CN114520089A - Common Mode Filters, Terminal Equipment - Google Patents

Abstract

The application relates to a common mode filter and terminal equipment. The common mode filter includes: the first coil group, the second coil group and the third coil group are mutually parallel and are a first magnetic layer, a first coil layer, one or more middle coil layers, a second coil layer and a second magnetic layer which are sequentially arranged; the first coil group comprises a first wire in each coil layer; the second coil group comprises a second wire in each coil layer; the third coil group comprises a third trace in each coil layer; the wires of each coil group are connected together through the wire through holes, and at least two wires of the wires in the same coil layer are wound in parallel. According to the common mode filter and the terminal device provided by the embodiment of the application, distances between all coil groups of the common mode filter and the first magnetic layer and distances between all coil groups of the common mode filter and the second magnetic layer are respectively kept consistent under the same phase, so that the symmetry among different coil groups is improved, and the longitudinal transfer loss of the common mode filter is reduced.

Description

Common Mode Filters, Terminal Equipment

technical field

The present application relates to the field of electronic technology, and in particular, to a common mode filter and terminal equipment.

Background technique

As terminal products such as mobile phones, smart tablets, and laptops become smaller in size and thinner in thickness, high-speed data transmission interfaces (such as mobile industry processing) used by radio frequency antennas and multimedia systems such as cameras and displays Mobile Industry Processor Interface (MIPI) alliance, serdes (SERializer (serializer)/DESerializer (deserializer) for short) interface, and a transmission interface that supports embedded digital audio and video (Embedded Display Port, referred to as eDP) etc.) the space distance is getting smaller and smaller, and the coupling between them is stronger, resulting in more and more interference to the radio frequency system caused by high-speed data transmission methods such as MIPI, and at the same time, it is also more susceptible to the influence of radio frequency transmission power, which becomes an influence The key factor for the electromagnetic compatibility coexistence of radio frequency and multimedia system on terminal products such as mobile phones. In order to solve the coexistence problem of RF and high-speed differential data transmission modules such as MIPI, Serdes, and eDP, a common mode filter with high common mode rejection, low vertical transfer loss and good symmetry is required to solve the problem of common mode filter in related technologies. The problem is that the symmetry is poor, and the common mode noise is easily converted into differential mode noise, so that the filtering effect of the common mode filter on the common mode interference noise is reduced.

SUMMARY OF THE INVENTION

In view of this, a common mode filter and terminal equipment with high symmetry and low vertical transfer loss are proposed.

In a first aspect, embodiments of the present application provide a common mode filter, including: multiple coil sets, multiple routing vias, and a first magnetic layer, a second magnetic layer, and multiple coil layers that are parallel to each other, The plurality of coil groups at least include a first coil group, a second coil group, and a third coil group, and the plurality of wiring vias at least include a first wiring via, a second wiring via, and a third wiring via wire vias, the plurality of coil layers include a first coil layer, at least one intermediate coil layer, and a second coil layer, each coil layer is provided with at least a first wiring, a second wiring and a third wiring, The first coil layer, the intermediate coil layer, and the second coil layer are sequentially stacked between the first magnetic layer and the second magnetic layer; the first coil group includes each coil layer the first trace in each coil layer, the second coil group includes the second trace in each coil layer, the third coil group includes the third trace in each coil layer; the first trace The via holes are used for connecting together a plurality of first wirings of the first coil group, the second wiring vias are used for connecting together a plurality of second wirings of the second coil group, The third wiring via is used to connect a plurality of third wirings of the third coil group together; wherein the first wiring, the second wiring and all the At least two of the third wirings are wired in parallel. The distances between all coil groups and the first magnetic layer and the second magnetic layer are kept the same respectively under the same phase, thereby improving the symmetry between different coil groups and reducing the longitudinal transfer loss of the common mode filter.

In a second aspect, embodiments of the present application provide a common-mode filter, including: a plurality of coil sets, a plurality of routing vias, and a first magnetic layer, a second magnetic layer, and a plurality of coil layers that are parallel to each other, The plurality of coil groups at least include a first coil group, a second coil group, and a third coil group, and the plurality of wiring vias at least include a first wiring via, a second wiring via, and a third wiring via wire vias, the plurality of coil layers include a first coil layer, at least one intermediate coil layer, and a second coil layer, each coil layer is provided with at least a first wiring, a second wiring and a third wiring, The first coil layer, the middle coil layer, and the second coil layer are arranged between the first magnetic layer and the second magnetic layer in sequence; the first coil group includes in each coil layer the first wiring of each coil layer, the second coil group includes the second wiring in each coil layer, the third coil group includes the third wiring in each coil layer; the first wiring is The holes are used to connect together a plurality of first wires of the first coil group, and the second wire vias are used to connect a plurality of second wires of the second coil group together, so The third wiring via is used to connect a plurality of third wirings of the third coil group together; wherein, the first wiring, the second wiring and the At least two of the third wirings are wound in parallel, and the wiring width of the same coil group satisfies any one of the following conditions: the width of the first wiring and the width of the second wiring are both the width of the first trace, the width of the third trace is the width of the second trace, and the width of the first trace and the width of the second trace are different; or, the width of the first trace, The width of the second trace and the width of the third trace are different, wherein the width of the first trace is the width of the first trace, and the width of the second trace is the width of the second trace width. Wherein, the first trace width and the second trace width satisfy: W1=p1×W2, W1 is the first trace width, W2 is the second trace width, p1 is a proportional coefficient, where p1∈[0.5,0.8] or p1∈[2,3].

Through the above arrangement, the distances between all coil groups and the first magnetic layer and the second magnetic layer are kept the same in the same phase, thereby improving the symmetry between different coil groups and reducing the longitudinal transfer loss of the common mode filter. . In addition, since the width of the traces of each coil group is set according to the preset width proportional relationship, it can further improve the thickness of the traces of different coil groups due to the difference in the sum of the lengths of multiple traces in different coil groups and the processing technology. Different, due to the difference in impedance caused by the inconsistency of the phase between the traces of different coil groups due to the position setting of the trace holes, the trace width of different coil groups can be adjusted by adjusting the width ratio relationship, so that different coil groups can be adjusted. The groups have similar or the same characteristic impedance, which improves the symmetry between different coil groups and reduces the longitudinal transfer loss of the common mode filter.

According to the first aspect or the second aspect, in a first possible implementation manner of the common mode filter, between the first wiring, the second wiring and the third wiring in the first coil layer having a first relative positional relationship, a second relative positional relationship among the first wiring, the second wiring and the third wiring in the second coil layer, and the first wiring in the middle coil layer There is an intermediate relative positional relationship between the second wiring and the third wiring, wherein the first relative positional relationship, the second relative positional relationship and the intermediate relative positional relationship are the same, and are used to achieve adjacent The centerlines of the first wiring vias connected by the first wiring, the second wiring vias connected by the second wirings, and the third wiring vias connected by the third wirings in the coil layer are located perpendicular to each on the same section of each coil layer. The distances between all coil groups and the first magnetic layer and the second magnetic layer are kept the same under the same phase; and in each coil layer, the relative positional relationship between the wires of different coil groups is the same, which can further improve the performance of different coil groups. Symmetry between groups, reducing the vertical transfer loss of the common mode filter.

According to the first aspect or the second aspect, in a second possible implementation manner of the common mode filter, between the first wiring, the second wiring and the third wiring in the first coil layer having a first relative positional relationship, a second relative positional relationship among the first wiring, the second wiring and the third wiring in the second coil layer, and the first wiring in the middle coil layer , There is an intermediate relative positional relationship between the second wiring and the third wiring, wherein the first relative positional relationship, the second relative positional relationship and the intermediate relative positional relationship are inconsistent, and the first coil the sum of the first lengths of the plurality of first traces of the group, the sum of the second lengths of the plurality of second traces of the second coil group, the third length of the plurality of third traces of the third coil group Always the same. The distances between all coil groups and the first magnetic layer and the second magnetic layer are kept consistent under the same phase; and by changing the relative positional relationship between the wires of different coil groups in each coil layer, the The sum of the winding lengths is the same, which further improves the symmetry between different coil sets and reduces the longitudinal transfer loss of the common mode filter.

According to the first aspect or the second aspect, in a third possible implementation manner of the common mode filter, between the first wiring, the second wiring and the third wiring in the first coil layer having a first relative positional relationship, a second relative positional relationship among the first wiring, the second wiring and the third wiring in the second coil layer, and the first wiring in the middle coil layer , the second wiring and the third wiring have an intermediate relative positional relationship, wherein the first relative positional relationship, the second relative positional relationship and the intermediate relative positional relationship are the same, and the first coil the sum of the first lengths of the plurality of first traces of the group, the sum of the second lengths of the plurality of second traces of the second coil group, the third length of the plurality of third traces of the third coil group The sum is the same. Make all coil groups keep the same distance from the first magnetic layer and the second magnetic layer under the same phase, and keep the same relative positional relationship between the traces of different coil groups in each coil layer. Changing the lengths of traces in different coil layers makes the sum of the lengths of the windings between different coil groups the same, which further improves the symmetry between different coil groups and reduces the longitudinal transfer loss of the common mode filter.

According to the first aspect, the second aspect, the first possible implementation manner, the second possible implementation manner, or the third possible implementation manner, in the fourth possible implementation manner of the common mode filter , the common mode filter further includes a reference ground structure, the reference ground structure is insulated from each of the first traces, each of the second traces and each of the third traces, and the reference ground structure is separate from all the The first magnetic layer and the second magnetic layer are both insulated. By setting the reference ground structure,

According to a fourth possible implementation manner, in a fifth possible implementation manner of the common mode filter, the reference ground structure includes a first auxiliary layer and a second auxiliary layer,

The first auxiliary layer is located between the first coil layer and the first magnetic layer, and the first auxiliary layer is provided with a first wiring and a second wiring in the first coil layer. , the first reference ground lines corresponding to the third traces respectively;

The second auxiliary layer is located between the second coil layer and the second magnetic layer, and the second auxiliary layer is provided with the first wiring, the second wiring and the first wiring in the second coil layer. The second reference ground lines corresponding to the three traces respectively. Make all coil groups keep the same distance from the first magnetic layer and the second magnetic layer under the same phase; and by setting the first auxiliary layer and the second auxiliary layer with the reference ground wire, the different coil groups have similar distances. The impedance to ground further improves the symmetry between different coil sets and reduces the longitudinal transfer loss of the common mode filter.

According to a fourth possible implementation manner, in a sixth possible implementation manner of the common mode filter, the reference ground structure includes: a first accompanying reference ground line, a middle accompanying reference ground line, and a second accompanying reference A ground wire, wherein the first coil layer is provided with a first accompanying reference ground of one or more first target wires among the first wire, the second wire, and the third wire of the first coil layer line, the first accompanying reference ground line is located on one side or both sides of the first target line;

The intermediate coil layer is provided with one or more intermediate target traces of the first trace, the second trace, and the third trace of the intermediate coil layer. The intermediate accompanying reference ground wire, the intermediate accompanying reference ground wire The ground wire is located on one or both sides of the intermediate target trace;

The second coil layer is provided with a second accompanying reference ground line of one or more second target lines among the first line, the second line, and the third line of the second coil layer, so The second accompanying reference ground line is located on one side or both sides of the second target line. The distance between all coil groups and the first magnetic layer and the second magnetic layer is kept the same under the same phase, and by setting the accompanying reference ground wire, different coil groups have similar ground impedance, and further improve the different coil groups. The symmetry between the groups reduces the vertical transfer loss of the common mode filter.

According to a sixth possible implementation manner, in a seventh possible implementation manner of the common mode filter, the first accompanying reference ground, the intermediate accompanying reference ground, and the second accompanying reference ground wire together. In this way, compared with the fourth possible implementation, it can further ensure that different coil groups have similar impedances to ground.

According to four possible implementation manners, in an eighth possible implementation manner of the common mode filter, the reference ground structure includes at least one of the following metal reference ground layers:

a first metal reference ground layer, located between the first coil layer and the first magnetic layer;

a second metal reference ground layer located between the second coil layer and the second magnetic layer;

A third metal reference ground layer is located between the first coil layer and the intermediate coil layer, and is provided with a first wiring via hole, a second wiring via hole, the first accommodating hole of the third wiring via;

The fourth metal reference ground layer is located between the second coil layer and the middle coil layer, and is provided with a first wiring via hole, a second wiring via hole, the second accommodating hole of the third wiring via;

an intermediate metal reference ground layer, the intermediate metal reference ground layer includes one or more, each intermediate metal reference ground layer is located between two intermediate coil layers, and is provided with a first trace accommodating through the third metal reference ground layer The third accommodating hole of the via hole, the second wiring via hole, and the third wiring via hole. Make all coil groups keep the same distance from the first magnetic layer and the second magnetic layer in the same phase, and compared with the common mode filter set in other possible implementations, by setting the metal reference ground layer, the difference between different coil groups can be achieved. They have similar impedance to ground, and further improve the symmetry between different coil groups and reduce the longitudinal transfer loss of the common mode filter.

According to an eighth possible implementation manner, in a ninth possible implementation manner of the common mode filter, when there are multiple metal reference ground layers, the multiple metal reference ground layers are connected through reference ground vias Together, the reference ground vias are provided in one or more of the first coil layer, the second coil layer, and the intermediate coil layer. And compared with the sixth possible implementation, the difference in impedance to ground between different coil groups can be further reduced by setting reference ground vias.

According to the first aspect, the second aspect, or any one of the above nine possible implementation manners, in a tenth possible implementation manner of the common mode filter, the common mode filter further comprises mutually parallel A third magnetic layer and a fourth magnetic layer, the first coil layer, the intermediate coil layer, and the second coil layer are located between the third magnetic layer and the fourth magnetic layer, and the first coil layer is located between the third magnetic layer and the fourth magnetic layer. The three magnetic layers are perpendicular to the first magnetic layer and the second magnetic layer, respectively, and the fourth magnetic layer is perpendicular to the first magnetic layer and the second magnetic layer, respectively. The distances between all coil groups and the first magnetic layer, the second magnetic layer, the third magnetic layer, and the fourth magnetic layer are kept the same under the same phase, and compared with the first magnetic layer, the second magnetic layer only The common mode filter arranged in this manner enables multiple coil groups to be in the same magnetic environment in two dimensions, further improving the symmetry between different coil groups and reducing the longitudinal transfer loss of the common mode filter.

According to a tenth possible implementation manner, in an eleventh possible implementation manner of the common mode filter, the common mode filter further includes a fifth magnetic layer and a sixth magnetic layer that are parallel to each other,

The first coil layer, the middle coil layer, and the second coil layer are located between the fifth magnetic layer and the sixth magnetic layer, and the fifth magnetic layer is perpendicular to the first magnetic layer, respectively The magnetic layer, the second magnetic layer, the third magnetic layer and the fourth magnetic layer, the sixth magnetic layer is perpendicular to the first magnetic layer, the second magnetic layer, the three magnetic layers and the fourth magnetic layer. The distances between all coil groups and the first magnetic layer, the second magnetic layer, the third magnetic layer, the fourth magnetic layer, the fifth magnetic layer and the sixth magnetic layer are kept the same respectively under the same phase, and compared with only the The method of the first magnetic layer and the second magnetic layer only includes the common mode filter arranged in the manner of the first magnetic layer, the second magnetic layer, the third magnetic layer and the fourth magnetic layer, so that the multiple coil groups can be arranged in three dimensions. Being in the same magnetic environment in the three-dimensional space further improves the symmetry between different coil groups and reduces the longitudinal transfer loss of the common mode filter.

According to a fourth possible implementation manner, in a twelfth possible implementation manner of the common mode filter, the reference ground structure includes a metal reference ground cladding layer, and the metal reference ground cladding layer covers on the surface of the common mode filter. The distances between all coil groups and the magnetic layer in the same phase are kept the same, and compared with the common mode filter set in the first aspect, multiple coil groups can be in the same reference ground environment in the three-dimensional space , the impedance to ground is the same, which further improves the symmetry between different coil groups and reduces the longitudinal transfer loss of the common mode filter.

According to a fourth possible implementation manner, in a thirteenth possible implementation manner of the common mode filter, the reference ground structure further includes a pad and a metal reference ground respectively connected to the terminals of each coil group strips, a portion of each pad is located on a first side of the common mode filter and another portion of each pad is located in a plurality of second sides on the common mode filter connected to the first side one; the metal reference ground strip is located between a plurality of bonding pads and surrounds at least a partial area of the first side surface of the common mode filter and the second side surface with bonding pads. The distances between all coil groups and the magnetic layer are kept the same under the same phase, and compared with the common mode filter set in the first aspect, different coil groups have similar ground impedances at the pad positions, which further improves the The symmetry between different coil sets is improved, and the longitudinal transfer loss of the common mode filter is reduced.

In a third aspect, an embodiment of the present application provides a terminal device, where the terminal device includes the common mode filter of the first aspect, the second aspect, or any one of the thirteen possible implementation manners.

These and other aspects of the present application will be more clearly understood in the following description of the embodiment(s).

Description of drawings

The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate exemplary embodiments, features and aspects of the application and together with the description, serve to explain the principles of the application.

FIG. 1 a , FIG. 1 b , and FIG. 1 c show schematic diagrams of wiring structures of a common mode filter in the related art.

FIG. 1d shows a perspective view of a common mode filter according to an embodiment of the present application.

FIG. 1e shows a front view of a common mode filter according to an embodiment of the present application.

Figure 1f shows a side view of a common mode filter according to an embodiment of the present application.

FIG. 1g shows a top view of a common mode filter according to an embodiment of the present application.

FIG. 1h shows a cross-sectional view of a common mode filter according to an embodiment of the present application.

FIG. 2a shows a cross-sectional view of a common mode filter according to an embodiment of the present application.

FIG. 2b shows a schematic structural diagram of a common mode filter according to an embodiment of the present application.

FIG. 2c shows a schematic structural diagram of a coil layer of a common mode filter according to an embodiment of the present application.

FIG. 3a shows a cross-sectional view of a common mode filter according to an embodiment of the present application.

FIG. 3b shows a schematic structural diagram of a common mode filter according to an embodiment of the present application.

FIG. 4 shows a schematic structural diagram of a common mode filter according to an embodiment of the present application.

FIG. 5a shows a cross-sectional view of a common mode filter according to an embodiment of the present application.

FIG. 5b shows a schematic structural diagram of a common mode filter according to an embodiment of the present application.

6a and 6b illustrate cross-sectional views of a common mode filter according to an embodiment of the present application.

FIG. 6c shows a schematic structural diagram of a common mode filter according to an embodiment of the present application.

FIG. 7a shows a cross-sectional view of a common mode filter according to an embodiment of the present application.

FIG. 7b shows a schematic structural diagram of a common mode filter according to an embodiment of the present application.

FIG. 7c shows a schematic structural diagram of a common mode filter according to an embodiment of the present application.

FIG. 8a shows a schematic structural diagram of a common mode filter according to an embodiment of the present application.

FIG. 8b shows a cross-sectional view of a common mode filter according to an embodiment of the present application.

FIG. 9a shows a schematic structural diagram of a common mode filter according to an embodiment of the present application.

FIG. 9b shows a cross-sectional view of a common mode filter according to an embodiment of the present application.

FIG. 10a shows a schematic structural diagram of a common mode filter according to an embodiment of the present application.

FIG. 10b shows a cross-sectional view of a common mode filter according to an embodiment of the present application.

FIG. 11a shows a schematic structural diagram of a common mode filter according to an embodiment of the present application.

FIG. 11b shows a cross-sectional view of a common mode filter according to an embodiment of the present application.

12a-12d show a perspective view and a three-view view of a common mode filter according to an embodiment of the present application.

13a-13d show a perspective view and three views of a common mode filter according to an embodiment of the present application.

FIG. 14a shows a cross-sectional view of a common mode filter according to an embodiment of the present application.

FIG. 14b shows a schematic diagram of multiple coil layers of a common mode filter according to an embodiment of the present application.

Detailed ways

Various exemplary embodiments, features and aspects of the present application will be described in detail below with reference to the accompanying drawings. The same reference numbers in the figures denote elements that have the same or similar function. While various aspects of the embodiments are shown in the drawings, the drawings are not necessarily drawn to scale unless otherwise indicated.

The word "exemplary" is used exclusively herein to mean "serving as an example, embodiment, or illustration." Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments.

In addition, in order to better illustrate the present application, numerous specific details are given in the following detailed description. It should be understood by those skilled in the art that the present application may be practiced without certain specific details. In some instances, methods, means, components and circuits well known to those skilled in the art have not been described in detail so as not to obscure the subject matter of the present application.

In the related art, a common mode inductor (a type of common mode filter) is usually composed of two coils, the number of turns and phases of the two coils are the same, and the two coils are wound around the same iron core. Because the common mode coil is wound in the same phase, when a differential mode current of equal amplitude and opposite phase flows through the common mode inductor, the differential mode current can generate a reverse magnetic field in the coil, so that the magnetic fields cancel each other and reduce the inductance effect. , the common mode inductor usually has no attenuation effect on the differential mode current, and the main factor affecting the differential mode current is the resistance of the common mode inductor coil. When a common mode current of equal amplitude and phase flows through the common mode inductor, since the common mode current has the same direction, the magnetic field generated in the common mode inductor coil is also in the same direction, thereby increasing the inductive reactance of the common mode inductor coil. , so that the coil exhibits high impedance, which will produce a strong damping effect, so that the common mode current can be attenuated and the filtering effect can be achieved. Common-mode filter devices with more than 2 wires (that is, more than 2 coils) have broad application prospects in high-speed data transmission, such as the C-PHY interface for MIPI (Mobile Industry Processor Interface, mobile industry processor interface). Abbreviation for port physical layer, English Port Physics Layer, C-PHY is a standard of port physical layer specified by MIPI) common mode filter of data transmission mode, which consists of three coils, and the three coils are coupled through coupling, Two-by-two differentials can filter out common-mode noise. In the related art, FIG. 1a, FIG. 1b, and FIG. 1c show schematic diagrams of the wiring structure of the common mode filter in the related art. Among them, the traces marked "A", "B", and "C" are the traces of three different coil groups. As shown in Figure 1a, the wirings of the three coil groups are arranged in an equilateral triangle, the wirings of the "A" and "B" coil groups are on the same layer, and the wirings of the "C" coil group are on a separate layer. In this way, The distances between the traces of the three coil groups relative to the ferrite are inconsistent, resulting in different phases between different coil groups. When the differential current signal flows through the common mode filter and performs a pairwise differential operation, it is difficult to completely align the common mode current. Cancellation, so that part of the common mode current is converted into differential mode current, resulting in differential mode noise. As shown in Figure 1b, the wiring of the three coil groups is also arranged in an equilateral triangle, and the wiring of the three coil groups "A", "B", and "C" are not on the same layer. In this way, the three coil groups The distance between the traces of the ferrite and the ferrite is inconsistent, which will also cause the phase between different coil groups to be different, so there is a problem of common mode to differential mode. As shown in Figure 1c, the traces of the three coil groups "A", "B" and "C" are not on the same layer. The traces of one coil group are wound in two layers, and the traces of the three coil groups are opposite to each other. Inconsistent distances between ferrites will also lead to different phases between different coil groups, resulting in the problem of common mode to differential mode. To sum up, the common mode filter device with more than 2 lines in the related art has the problem of poor symmetry, and it is easy to convert the common mode noise into differential mode noise, so that the filtering effect of the filter device on the common mode interference noise is reduced. In general, the common-mode slip characteristic of a common-mode filter is referred to as vertical transfer loss. How to provide a common mode filter with high symmetry and low vertical transfer loss is an urgent technical problem to be solved. To solve the above technical problems, the present application provides a common mode filter.

The common mode filter provided by the present application includes a plurality of coil groups, a first magnetic layer parallel to each other, a second magnetic layer, a first coil layer, an intermediate coil layer, a second coil layer, and a plurality of wiring vias. The first coil layer, the intermediate coil layer, and the second coil layer are sequentially disposed between the first magnetic layer and the second magnetic layer. The number of multiple coil groups can be at least three, and the multiple wires of each coil group are distributed in each coil layer respectively, and then the length of the wires of different coil groups in the same coil layer and the distance between the wires are determined. The relative position relationship and the line width ratio of the traces are set to obtain a common mode filter with high symmetry and low vertical transfer loss. For common-mode filters with different usage requirements, the structural layout settings such as the number of coil groups, the number of coil layers, the number and position of wiring vias can be adjusted accordingly, and those skilled in the art can set them as needed. This is not a limitation, but for the convenience of intuitively and clearly describing the layout of the coil group in the common mode filter, the following description takes "three coil groups in the common mode filter" as an example, and uses "A", "B" and "B" as an example. ” and “C” respectively represent three coil groups. When the number of coil groups is greater than 3, those skilled in the art can make corresponding adjustments with reference to the layout setting of "setting 3 coil groups in the common mode filter", which will not be repeated in this application.

Fig. 1d shows a perspective view of a common mode filter according to an embodiment of the present application, and Fig. 1e shows a front view of the common mode filter according to an embodiment of the present application. Figure 1f shows a side view of a common mode filter according to an embodiment of the present application. FIG. 1g shows a top view of a common mode filter according to an embodiment of the present application. FIG. 1h shows a cross-sectional view of a common mode filter according to an embodiment of the present application, and FIG. 1h is a cross-sectional view obtained by cutting along the position of the dotted frame area s3 in FIG. Only the part related to the coil group is shown in the cross-sectional view 1h. Among them, the dotted frame area s2 in Fig. 1e, the dotted frame area s3 in Fig. 1f, and the dotted frame area s1 in Fig. 1g correspond to the same space area of the common mode filter.

An embodiment of the present application provides a common mode filter. As shown in FIG. 1h, the common mode filter includes a plurality of coil groups (the difference between the traces of different coil groups is not shown in FIG. 1h), a plurality of coil groups Trace vias, a first magnetic layer 11 parallel to each other, a second magnetic layer 12 , a plurality of coil layers, the plurality of coil layers including a first coil layer 21 , a second coil layer 22 , and one or more intermediate coils Layer 23 (in FIG. 1h, there are multiple intermediate coil layers for exemplary illustration), each coil layer is provided with at least a first wiring, a second wiring and a third wiring. The multiple coil groups at least include a first coil group A, a second coil group B, and a third coil group C (because the relative positional relationship between the wires of different coil groups in the same coil layer is not defined in FIG. The first coil group A, the second coil group B and the third coil group C are shown differentially, but reference can be made to the illustrations in Fig. 2a, Fig. 3a, Fig. 5a, Fig. 6a, Fig. 6b, Fig. 7a, Fig. 14a) , the plurality of wiring vias at least include a first wiring via, a second wiring via, and a third wiring via (not shown in FIG. 1h ).

Wherein, the first coil layer 21 , the intermediate coil layer 23 and the second coil layer 22 are sequentially arranged between the first magnetic layer 11 and the second magnetic layer 12 .

The first coil group A includes the first wiring in each coil layer, that is, the first coil group A includes the first wiring in the first coil layer 21 and the second coil layer 22 The first wiring in the middle coil layer 23 and the first wiring in the middle coil layer 23 . The second coil group B includes the second wiring in each coil layer, that is, the second coil group B includes the second wiring in the first coil layer 21 and the second coil layer 22 The second wiring in the middle coil layer 23 and the second wiring in the middle coil layer 23 . The third coil group C includes the third wiring in each coil layer, that is, the third coil group C includes the third wiring in the first coil layer 21 and the second coil layer 22 . The third wiring in the middle coil layer 23 and the third wiring in the middle coil layer 23 .

The first wiring via is used for connecting a plurality of first wirings of the first coil group together, and the second wiring via is used for connecting a plurality of second wirings of the second coil group together. The wirings are connected together, and the third wiring via is used to connect a plurality of third wirings of the third coil group together. At least two of the first trace, the second trace and the third trace in the same coil layer are wound in parallel.

In this embodiment of the present application, different coil groups are insulated from each other. An insulating layer of insulating material such as a dielectric can be added to the surface of each trace, or an interval can be set between different traces of the same coil layer, and adjacent The insulation between different coil groups can be achieved by arranging insulating materials such as dielectrics between the coil layers. For example, the insulating materials can be resin materials, ceramic materials, polymer materials, etc., and those skilled in the art can implement different coil groups according to their needs. They are set in a mutually insulating manner, which is not limited in this application.

In the embodiments of the present application, the first wiring vias, the second wiring vias, and the third wiring vias provided in each intermediate coil layer are not connected, contacted, and insulated from each other to ensure that Mutual isolation between different coil sets. The material filled in the first wiring via, the second wiring via, and the third wiring via is metal, which can be exactly the same as the wiring material of the corresponding coil group, such as copper, silver, gold, tungsten Other metals with good electrical conductivity can also be made of different metals from the wiring of the corresponding coil group. For example, the wiring material of the coil group is copper metal, and the filling material in the wiring via hole is silver metal, which is not covered in this application. limit.

In the embodiments of the present application, the materials of the first magnetic layer 11 and the second magnetic layer 12 may be magnetic materials such as ferrite, such as alloys, monomers or oxides containing elements such as Fe, Co, Ni, Mn, etc., This application does not limit this. In addition, the adjacent layers among the first magnetic layer 11 , the second magnetic layer 12 , and the plurality of coil layers (including the first coil layer 21 , the second coil layer 22 and the one or more intermediate coil layers 23 ) are insulated from each other. of. Insulation between adjacent layers can be achieved by adding an insulating layer or the like, and the material of the insulating layer can be insulating materials such as resin material, ceramic material, polymer material, etc., which is not limited in this application. The first magnetic layer and the second magnetic layer are set with spatial dimensions such as thickness, length, width, etc., which can be adjusted according to the limitations of processing technology, longitudinal transfer loss, differential mode loss, return loss, impedance index parameters, etc. Thickness, length and width are set, which are not limited in this application. However, in order to simplify the structure of the common mode filter, strengthen the wiring and the positional relationship of each layer in the common mode filter, the drawings of this application do not describe the dimensions of the first magnetic layer and the second magnetic layer in detail. It should not be considered a limitation of this application.

In this embodiment of the present application, at least two parallel windings among the multiple wirings in the same coil layer may include: two or more wirings are wound in parallel together, as shown in FIG. 2b, FIG. 2c, and FIG. 3b. Wire the wires together in parallel for multiple walks in each coil layer. At least two parallel windings in the plurality of wires in the same coil layer may include all or part of each wire wound together in parallel to participate in the winding of "all the wires wound together in parallel", and the other part participates in the winding of "all wires wound together in parallel". Parallel routing of one or more of the other routes in "All Routes Routed in Parallel Together". The distance between each trace in the same coil layer and the first magnetic layer is consistent, and the distance from the second magnetic layer is also the same (multiple traces in the same coil layer and the first magnetic layer and the second magnetic layer are also consistent. different distances between layers). The parallel winding of at least two wires in the same coil layer means that the wires in the same coil layer that need to be wound in parallel are wound in parallel to each other. Parallel-wound traces have the same phase between them.

For example, as shown in Figures 2b and 2c below, the multiple wires in each coil layer are all wound together in parallel, and the entire length of each wire participates in the parallel winding of the multiple wires. As shown in Figure 3b below, the multiple traces in each coil layer are all wound in parallel, but due to the difference in trace length, some traces cannot participate in the parallel winding with all other traces in the same coil layer. , and the rest of the length that does not participate in the "parallel winding with all other traces on the same coil layer" will continue to run in parallel with one or more of the remaining traces...until the full length is used up, and if it is time to go If the wire is the longest trace in the coil layer, it will have the remaining part of its length and cannot participate in any parallel winding. For example, in "Layer 1", the first trace a, the second trace b and the third trace c are wired together in parallel, but only the full length of the shortest second trace b participates in the three traces together. Parallel winding; part of the first line b participates in the parallel winding of the 3 lines together, and part participates in the parallel winding with the third line c; part of the third line c participates in the parallel winding of the 3 lines together Parallel winding, one part participates in parallel winding with the second trace b, and the last part is not parallel winding. As shown in Figure 4 below, although all the traces in each coil layer are also wound in parallel, due to the limitation of the length of different traces, in the "6th layer", the second trace b is only small. Part of it participates in the parallel winding of the three traces, and the rest is paralleled with the third trace c; only a small part of the first trace a participates in the parallel winding of the three traces, and a large part It is wound in parallel with the third trace c, and the other small part does not perform any wiring; only a small part of the third trace c also participates in the parallel winding of the three traces, and is wound in parallel with the first trace a Wire, a small part without any winding.

It should be noted that, in the actual manufacturing process of the common mode filter, the multiple coil layers, the first magnetic layer, and the second magnetic layer are in direct contact and closely attached together. The distances between different layers in the examples are only to illustrate the structure of the common mode filter more clearly, and do not limit the present application.

The common mode filter is set as shown in Fig. 1h, so that all coil groups including at least the first coil group, the second coil group, and the third coil group maintain the distance from the first magnetic layer and the second magnetic layer respectively under the same phase Consistent, thereby improving the symmetry between different coil sets and reducing the longitudinal transfer loss of the common mode filter.

Fig. 2a shows a cross-sectional view of a common mode filter according to an embodiment of the present application, and Fig. 2b shows a schematic structural diagram of the common mode filter according to an embodiment of the present application. Fig. 2a is a cross-sectional view obtained by cutting along the position of the dotted frame area s3 in Fig. 1h. In order to facilitate the understanding of the wiring layout of the coil assembly in the present application, only the cross-sectional view related to the coil assembly is shown in Fig. 2a. part. In a possible implementation manner, in each coil layer, the relative positional relationship between the traces of different coil groups is the same. In the same coil layer, the centerlines of the routing vias of each coil group are located on the same section perpendicular to the coil layer. Wherein, different segments of each trace in the same coil layer can be perpendicular to, parallel to, or located on the cross section. In the first coil layer 21, the first wire belonging to the first coil group A, the second wire belonging to the second coil group B, and the third wire belonging to the third coil group C have a first relative relationship. Positional relationship. In the second coil layer, the first wire belonging to the first coil group A, the second wire belonging to the second coil group B, and the third wire belonging to the third coil group C have a second relative position between them relation. There is an intermediate relative positional relationship among the first wires belonging to the first coil group A, the second wires belonging to the second coil group B, and the third wires belonging to the third coil group C in the middle coil layer. Wherein, as shown in Fig. 2a and Fig. 2b, the first relative positional relationship, the second relative positional relationship and the intermediate relative positional relationship are the same, and the first relative positional relationship is used to realize the wiring connection in the adjacent coil layers. The centerlines of the first wiring via hole Aa, the second wiring via hole Bb, and the third wiring via hole Cc are all located on the same section perpendicular to each coil layer. The “circular dotted frame” set on the trace in FIG. 2b is the position of the trace via to which the trace is connected.

Among them, as shown in Figure 2b, in each coil layer, the traces marked "a", "b", and "c" are the first trace, the second trace and the third trace of the coil layer where they are located, respectively. Lines, that is, the first line is "a", the second line is "b", and the third line is "c", then the multiple lines of the first coil group A are the first coil layer "No. 1", multiple intermediate coil layers "2 to 5", the traces marked "a" in the second coil layer "6". The multiple traces of the second coil group B are the first coil layer "Layer 1", the multiple intermediate coil layers "Layer 2 to Layer 5", and the second coil layer "Layer 6" marked as " b” trace. The multiple traces of the third coil group C are the first coil layer "Layer 1", the multiple intermediate coil layers "Layer 2 to Layer 5", and the second coil layer "Layer 6" marked as " c" trace.

In this implementation manner, the first relative positional relationship, the second relative positional relationship, and the intermediate relative positional relationship may refer to the adjacency relationship, the adjacent relationship, etc. between the traces, as shown in FIG. , The second relative positional relationship is the same as the intermediate relative positional relationship", that is, the first coil layer "1st layer", multiple intermediate coil layers "2nd to 5th layer", the second coil layer "6th layer" In each coil layer, the first trace a is at the outermost side, the third trace c is at the innermost side, and the second trace b is between the first trace a and the third trace c, that is, The relative positional relationship of the three traces is "a-b-c".

In this implementation, as shown in FIG. 2b, the “3rd layer” in the middle coil layer 23 and the first route for realizing the “2nd layer and the wiring connection of each coil group in the 3rd layer” Take the line via hole Aa, the second line via hole Bb, and the third line via hole Cc" as an example, in "Layer 3", between the "Layer 3" and The first wiring via hole Aa of the coil group A, the first wiring via hole Bb of the second coil group B, the first wiring via hole Cc of the third coil group C, the first wiring via hole Aa, the second wiring via hole The centerlines of the wiring vias Bb and the third wiring vias Cc (ie, the dotted lines shown in FIG. 2b ) are all located in the same section M, which is perpendicular to each coil layer. Since the first trace a, the second trace b, and the third trace c in "Layer 3" have multiple different segments, taking the first trace a in "Layer 3" as an example, The first trace a includes sections a1, a2, a3, a4, a5, wherein the section a1 is perpendicular to the section M, the section a2 is parallel to the section M, the section a3 is perpendicular to the section M, and the section a4 is perpendicular to the section M Parallel, segment a5 is perpendicular to section M. Similarly, "the first wiring via Aa, the second wiring via Bb, the third wiring via Cc connecting the wiring of each coil group in the 1st layer and the 2nd layer", "the 3rd layer The first wiring via Aa, the second wiring via Bb, the third wiring via Cc connected to the wiring of each coil group in the 4th layer", "the 4th and 5th layers in the The first wiring via hole Aa, the second wiring via hole Bb, the third wiring via hole Cc connected to the wiring of each coil group", "the wiring of each coil group in the 5th layer and the 6th layer" The centerlines of the first wiring via hole Aa, the second wiring via hole Bb, and the third wiring via hole Cc" for the wire connection are also on their corresponding cross-sections, respectively.

It should be noted that, in this application, Figure 2b and the following Figures 3b, 4, 5b, 6c, 7b-7c, and Figure 14b in order to simplify the winding method of multiple coil sets and clearly describe the winding structure, the number of turns of the first, second, and third wires of each coil layer is less than 2 turns. In actual production, the first, second, and third wires of each coil layer are The number of winding turns of the third wire may be any number of turns of one or more turns. In addition, in order to avoid the stress problem caused by tip discharge and right-angle turning, and also make the differential mode loss and return loss of the common mode filter smaller, the corner position of the trace can be made into an arc shape when winding (as shown in Figure 2c below). Show).

In this implementation manner, the number of layers of the multiple coil layers can be set according to the limitation of the index parameters of the longitudinal transfer loss, differential mode loss, return loss, and impedance of the common mode filter.

In this implementation, coils between two adjacent coil layers (first coil layer and adjacent middle coil layer, second coil layer and adjacent middle coil layer, two adjacent middle coil layers) The first wiring via hole Aa, the second wiring via hole Bb, and the third wiring via hole Cc required for the group wiring connection can be arranged in any one of the two coil layers, or can be arranged in any one of the two coil layers. Between two coil layers, or the first wiring via Aa, the second wiring via Bb, and the third wiring via Cc may also penetrate through each coil layer. The corresponding connection positions of the first wiring via hole Aa, the second wiring via hole Bb, and the third wiring via hole Cc in different coil layers (the position where the wiring via hole contacts the coil layer) can be the same or different. The setting positions of the first wiring via Aa, the second wiring via Bb, and the third wiring via Cc can be set according to actual needs, as long as the first wiring via Aa, the second wiring via Aa, and the second wiring via are ensured. The hole Bb and the third wiring via hole Cc can realize the electrical connection of the wirings in the first coil group, the second coil group, and the third coil group, which is not limited in this application. For example, the first wiring via hole Aa, the second wiring via hole Bb, and the third wiring via hole Cc required for the electrical connection of the coil group wiring between the first coil layer and the adjacent middle coil layer may be The ones arranged in the middle coil layer may also be arranged in the first coil layer, and may also be arranged between the first coil layer and the middle coil layer. The first wiring via hole Aa, the second wiring via hole Bb, and the third wiring via hole Cc required for the wiring connection of the coil group between the second coil layer and the adjacent middle coil layer can be arranged in the middle In the coil layer, it can also be disposed in the second coil layer, and can also be disposed between the middle coil layer and the second coil layer. The first wiring via hole Aa, the second wiring via hole Bb, and the third wiring via hole Cc required for the wiring connection of the coil group between two adjacent middle coil layers may be provided in the two middle coil layers. Any one of the layers can also be placed between two intermediate coil layers. It should be noted that, in fact, different coil layers are in direct contact and closely adhered to each other. The length of the trace via Cc is much longer than the thickness of the coil layer only to illustrate the structure of the common mode filter more clearly, not and does not limit the first trace via Aa and the second trace in the common mode filter. The actual length of the via hole Bb and the third wiring via hole Cc.

The common mode filter is set in the manner of Fig. 2a and Fig. 2b, so that the distances between all coil groups and the first magnetic layer and the second magnetic layer are kept the same under the same phase; and compared with the common mode filter set in Fig. 1h , in each coil layer, the relative positional relationship between the wires of different coil groups is the same, which can further improve the symmetry between different coil groups and reduce the longitudinal transfer loss of the common mode filter.

In this embodiment of the present application, each trace of different coil groups has a thickness and a width, and adjacent traces in the same coil layer may also have trace spacing, and can be adjusted according to the common mode filter. Longitudinal transfer loss, differential mode loss, return loss, impedance index parameters, processing technology limitations, etc., set the thickness and width of the traces, and trace spacing. Among them, the appearance length, width and thickness of the common mode filter used in the terminal equipment are 0.1mm-1mm, that is, the length, width and height of the three-dimensional space occupied by the common mode filter are 0.1mm-1mm. Taking the length, width and thickness of the common mode filter as 1mm as an example, the common mode filter adopts Low Temperature Co-fired Ceramic (LTCC), thin film bonding process, Integrated Passive Device (Integrated Passive Device) , referred to as IPD) process, limited by process, common mode filter size, vertical transfer loss, differential mode loss, return loss, impedance, the trace width is 5μm-30μm, and the trace spacing is 5μm-30μm. The thickness of the traces can be 0.1 μm-10 μm when the printing or electroplating process is used for processing and manufacturing. Those skilled in the art can set the trace thickness, trace width and trace spacing according to the actual design requirements of the common mode filter, which is not limited in this application. Considering the application of the common mode filter, it is necessary to ensure that its impedance is small, that is, the differential mode loss is small, that is, the differential mode current is not lost. Therefore, when making the common mode filter, the distance between the trace layers should be large enough to avoid the existence of stray capacitance, and the trace should have a certain thickness to avoid excessive DC resistance. In addition, the common mode filter should also have a specific filter band, and the control of the filter band is usually realized by adding ferromagnetic materials, that is, adding ferromagnetic materials on the upper and lower surfaces of the common mode filter, and the ferromagnetic materials have a certain loss. The tangent, which is a function of frequency, at some frequencies the loss tangent is larger. If there is a common-mode noise current flowing through the common-mode filter, the magnetic field generated by the common-mode current is dissipated as heat in the ferromagnetic material. In addition, the common mode filter provided in this application can be manufactured independently, the size of the manufactured common mode filter is relatively large, and it can only possibly meet its design requirements for the thickness and width of the traces, and various types of manufacturing can be used. The process realizes the manufacture of the common mode filter, and the resource cost, time cost and reliability of the common mode filter are low.

In a possible implementation manner, the trace widths of different traces in each coil layer in the common mode filter are set according to a preset width proportional relationship.

Wherein, the width proportional relationship may include any one of the following: the plurality of coil groups include one or more target coil groups and at least two coil groups of the same width, and the wires of different coil groups of the same width have the same first A trace width, the second trace width of each target coil set and the first trace width have a different first width proportional relationship; the multiple coil sets include one or more target coil sets and at least two coil sets of the same width, the traces of different coil sets of the same width have the same first trace width, and the traces of different target coil sets have the same second trace width, the second trace width There is a second width proportional relationship with the first trace width; the trace widths of the traces of each coil group are different from each other, and there is a third width ratio between the trace widths of the traces of different coil groups There is a corresponding fourth width proportional relationship between the trace widths of different traces in each coil layer.

Wherein, the trace width of the traces of each coil group may be the width of all traces of the coil group in different coil layers. Different traces of the same coil group can be set to have the same trace width, or different traces of the same coil group can be set to have inconsistent or different trace widths. When different traces of the same coil group have the same trace width, if the width proportional relationship is set, the first trace width of the same width coil group can be determined first, and then the trace width of the target coil group can be adjusted according to the width proportional relationship. Among them, the width proportional relationship between the first trace width W1 and the second trace width W2 is: W1=p1×W2, p1 is the proportional coefficient, and p1∈[0.5,0.8] or p1∈[2,3 ]. It is also possible to set multiple traces in the same coil layer to have inconsistent trace widths. Among the multiple traces, a reference trace can be determined first. The trace width w1 of the benchmark trace and the traces of the rest of the traces can be determined. The fourth proportional relationship between the widths w2 is: w1=p1×w2, p1 is a proportional coefficient, and P1∈[0.5,0.8] or P1∈[2,3].

In this way, since the trace width of each coil group is set according to the preset width proportional relationship, it is possible to further improve the thickness of the traces of different coil groups due to the difference in the sum of the lengths of multiple traces in different coil groups and the processing technology. Different, due to the difference in impedance caused by the inconsistency of the phase between the traces of different coil groups due to the position setting of the routing vias, the trace width of different coil groups can be adjusted by adjusting the width ratio relationship, so that different coil groups can be adjusted. The groups have similar or the same characteristic impedance, which improves the symmetry between different coil groups and reduces the longitudinal transfer loss of the common mode filter. Among them, when the thickness of the trace is the same, the smaller the trace width, the greater the corresponding impedance, because the impedance value is inversely proportional to the cross-sectional area of the trace, and the smaller the trace width, the smaller the cross-sectional area.

In order to facilitate the description of different ways of setting the ratio of the widths, the following description will be given by taking a plurality of coil groups including a first coil group A, a second coil group B, and a third coil group C as an example. Fig. 2c shows a schematic structural diagram of a coil layer of a common mode filter according to an embodiment of the present application. The difference between Figure 2c and Figure 2b is that in Figure 2c the width of the traces is set and the corners of the traces are set as arcs, so only the traces of the first coil layer "Layer 1" are shown in Figure 2c. There is only one target coil group, and other coil groups except "one target coil group" among the multiple coil groups are all coil groups of the same width. As shown in FIG. 2c, when the multiple coil groups include the first coil group A, the second coil group B, and the third coil group C, the first coil group A, the second coil group B, and the third coil group C can be selected. Any one of them is the target coil group, and the other coil groups are the same width coil group. For example, the third coil group C is the target coil group, the first coil group A and the second coil group B are the same width coil group, then W1a=W1b =p1*W2c, p1∈[0.5, 0.8]. Among them, since the first line a of the first coil group A, the second line b of the second coil group B, and the third line c of the third coil group C are sequentially from outside to inside, and the number of winding turns If there is more than one turn, you can choose to reduce the trace width of the first trace a and the second trace b; but you cannot adjust the impedance by increasing the trace width of the third trace c because, in order to ensure the first trace a. When the distance between the second trace b and the third trace c is the same and the coupling situation is the same, increasing the width of the third trace c will make the third trace c and the first trace a coupled closer, and even cause the two to be connected to cause a short circuit.

In the description of the following embodiments of the present application, in fact, the traces shown in Figs. 3b, 4, 5b, 6c, 7b, 7c, 8a, 9a, 10a, 11a and 14b They are all traces with thickness and width as shown in Figure 2b, but in order to simplify the structure of the common mode filter, strengthen the traces and the positional relationship of each layer in the common mode filter, in Figure 3b, Figure 4, Figure 5b, In Figs. 6c, 7b, 7c, 8a, 9a, 10a, 11a, and 14b, only "lines" with widths are used to illustrate wiring.

In the example given in FIG. 2b of the embodiment of the present application, the diameters of the first wiring via Aa, the second wiring via Bb, and the third wiring via Cc are the same as the width of the wiring to which they are connected. Processing technology (such as laser perforation, lithography, etc.), the electrical connection between traces, the width of traces, and the diameter of the traces vias. The diameter of the traces can be greater than, smaller than, or It is equal to the width of the traces to which it is connected, which is not limited in this application. Similarly, in Fig. 3b, Fig. 4, Fig. 5b, Fig. 6c, Fig. 7b, Fig. 7c, Fig. 8a, Fig. 9a, Fig. 10a, Fig. 11a, Fig. 14b two ends of each trace of the middle coil layer, the first One end of each trace of the coil layer and one end of each trace of the second coil layer are drawn with trace vias (that is, the circular illustrations of different grayscales shown in the figure), for convenience Indicates the location of the wiring via. The diameter of the wiring via is greater than the width of the wiring to which it is connected, but in fact the diameter of the wiring via can be greater than, less than, or equal to the width of the wiring to which it is connected. 2b, 3b, 4, 5b, 6c, 7b, 7c, 8a, 9a, 10a, 11a, 14b The diameter of the via hole shown in The size relationship between the widths of the traces does not limit the present application.

Fig. 3a shows a cross-sectional view of a common mode filter according to an embodiment of the present application, and Fig. 3b shows a schematic structural diagram of the common mode filter according to an embodiment of the present application. Fig. 3a is a cross-sectional view obtained by cutting along the position of the dotted frame area s3 in Fig. 1f. In order to facilitate the understanding of the wiring layout of the coil group in the present application, only the cross-sectional diagram related to the coil group is shown in Fig. 3a. part. In a possible implementation manner, the sum of the lengths of the windings between different coil groups is similar, and the sum of the lengths is the sum of the lengths of multiple wires in the same coil group, and the lengths of the different coil groups in each coil layer are The relative positional relationship between the lines is inconsistent. As shown in FIGS. 3 a and 3 b , in the first coil layer 21 , the first wire belonging to the first coil group A, the second wire belonging to the second coil group B, and the first wire belonging to the third coil group C There is a first relative positional relationship among the three wires. In the second coil layer, the first wire belonging to the first coil group A, the second wire belonging to the second coil group B, and the third wire belonging to the third coil group C have a second relative position between them relation. There is an intermediate relative positional relationship among the first wires belonging to the first coil group A, the second wires belonging to the second coil group B, and the third wires belonging to the third coil group C in the middle coil layer. Wherein, the first relative positional relationship, the second relative positional relationship and the intermediate relative positional relationship are inconsistent, and the sum of the first lengths of the multiple wires of the first coil group A, the second coil The sum of the second lengths of the multiple wires of the group B and the third sum of the lengths of the multiple wires of the third coil group C are the same.

In this implementation manner, during the actual processing of the common mode filter, the first length sum, the second length sum, and the third length sum are affected by the processing technology, etc., and the three cannot actually be completely identical. Therefore, in this In the application, "the sum of the first length, the sum of the second length and the sum of the third length are the same" is a theoretical state. "Sum" is substantially the same, approximately approximately, approximately equal. Alternatively, the length difference can also be set according to the index requirements related to the common mode filter, such as the differential mode loss, the longitudinal transfer loss, the required total length of the multiple wires of each coil group, and so on, so that the sum of the first length and the The actual length difference between the sum of the second length and the sum of the third length is all less than or equal to the difference in length, so as to ensure that the sum of the winding lengths between different coil groups is as same as possible, and further improve the symmetry between different coil groups sex. The smaller the difference in length is, the closer the sum of the winding lengths of different coil groups is (that is, the closer the first length sum, the second length sum, and the third length sum are), and the symmetry between the different coil groups is Sex is better.

In this implementation, as shown in Fig. 3a and Fig. 3b, the relative positional relationship between the traces of different coil groups in each coil layer is inconsistent, which may be in the "first layer" (the first coil layer 21). The relative positional relationship between the first trace a, the second trace b, and the third trace c is "a-b-c", and the first trace a, the second trace b, the "second layer" (the middle coil layer 23) The relative positional relationship of the third trace c is "c-a-b", and the relative positional relationship of the first trace a, the second trace b, and the third trace c in the "third layer" (intermediate coil layer 23) is "b-c-a" ”, the relative positional relationship of the first trace a, the second trace b, and the third trace c in the “4th layer” (the middle coil layer 23) is “c-a-b”, and the “5th layer” (the middle coil layer 23 ) in the relative positional relationship between the first trace a, the second trace b, and the third trace c is "b-c-a", the first trace a, the second trace in the "6th layer" (the second coil layer 22) The relative positional relationship between the line b and the third line c is "a-b-c". That is to say, in the multiple coil layers, there are multiple layers "the first layer and the sixth layer" with the same relative positional relationship between the first trace a, the second trace b, and the third trace c, but all the coil layers The relative positions of the first trace a, the second trace b, and the third trace c are not completely consistent, such as the first and sixth layers, the third and fifth layers, and the second and fourth layers. The relative positional relationships of the first wiring a, the second wiring b, and the third wiring c are respectively the same, and the other different layers are different.

In this implementation manner, the number of layers of the multiple coil layers and the sum of the winding lengths of each coil group can be set according to the limitations of the index parameters of the longitudinal transfer loss, return loss, and impedance of the common mode filter. This does not impose restrictions.

The common mode filter is set as shown in Fig. 3a and Fig. 3b, so that the distances between all coil groups and the first magnetic layer and the second magnetic layer are kept the same under the same phase; By changing the relative positional relationship between the traces of different coil groups in each coil layer (that is, changing the first relative positional relationship, the second relative positional relationship and the middle relative positional relationship) The sum of the winding lengths between them is similar, which further improves the symmetry between different coil groups and reduces the longitudinal transfer loss of the common mode filter.

In a possible implementation manner, FIG. 4 shows a schematic structural diagram of a common mode filter according to an embodiment of the present application, and the difference between the arrangement of different coil groups in the multiple coil layers shown in FIG. 4 and FIGS. 3 a and 3 b The relative positional relationship between the traces is set differently. As shown in FIG. 4 , the first relative positional relationship, the second relative positional relationship and the intermediate relative positional relationship are the same, and the sum of the first lengths of the multiple wires of the first coil group, the The sum of the second lengths of the plurality of wires of the second coil group and the third sum of the lengths of the plurality of wires of the third coil group are the same.

In this implementation, as shown in FIG. 4 , the relative positional relationship between the first trace a, the second trace b, and the third trace c in each coil layer is the same (that is, the first relative position relationship, the second relative positional relationship and the intermediate relative positional relationship are the same). In order to meet the requirement that the sum of the winding lengths between different coil groups is the same, the first, second and/or third wiring in the same coil group may be greater than or equal to a full circle, or may be If it does not satisfy a full circle, that is, the lengths of the first wiring, the second wiring and the third wiring in the same coil layer are not limited.

The common mode filter is set as shown in Fig. 4, so that the distances between all coil groups and the first magnetic layer and the second magnetic layer are kept the same under the same phase, and compared with the common mode set in Fig. 2a and Fig. 2b Filter, on the premise of keeping the same relative positional relationship between the wires of different coil groups in each coil layer, by changing the length of the wires in different coil layers to make the sum of the winding lengths between different coil groups the same , which further improves the symmetry between different coil groups and reduces the longitudinal transfer loss of the common mode filter.

2a, 2b, 3a, 3b, and 4 provide several common-mode filters, in this application, the common-mode filter setting may also include a reference ground structure, the reference ground The structure is insulated from each of the first traces, each of the second traces and each of the third traces, and the reference ground structure is insulated from the first magnetic layer and the second magnetic layer. The reference ground structure can be connected to the ground pin, empty or floating to make it the "reference ground" of the wiring in each coil group, which is not limited in this application. Through the setting of the ground reference structure, different coil groups can have similar or even the same ground matching impedance, so as to further improve the symmetry between different coil groups and reduce the longitudinal transfer loss of the common mode filter.

Wherein, the implementation manner of the reference ground structure may include the implementation manners of the following manners 1 to 4. In the common mode filter, one or more manners of the first manner to the fourth manner may be selected to perform the setting of the reference ground structure.

In a first way, the reference ground structure may be one or more internal reference ground layers located inside the common mode filter, such as the "metal reference ground layer" described below.

In the second way, the reference ground structure may be one or more internal reference ground wire layers located inside the common mode filter, and the reference ground wire layer is provided with a “reference ground” for the traces in the adjacent coil layers. ” of at least one ground reference. The corresponding reference ground wire layer can be set for each coil layer; the corresponding reference ground wire layer can also be set for some coil layers; the corresponding reference ground wire layer can also be set for some coil layers and used as the "Reference Place". The "first auxiliary layer and the second auxiliary layer" as described below are the "reference ground" of all coil layers.

In the third way, the reference ground structure can be one or more accompanying reference ground lines located in the coil layer of the common mode filter, as described in the following "the first accompanying reference ground line, the middle accompanying reference ground line and the second accompanying reference ground line". ground wire".

In the fourth way, the reference ground structure may be a surface reference ground structure located on the surface of the common mode filter, such as the "metal reference ground cladding layer" and "metal reference ground strip" described below.

It can be understood that those skilled in the art can set the position of the reference ground structure in the common mode filter, its own structure and size, etc. as required, as long as the reference ground structure can provide the traces of the coil assembly. For reference, it is sufficient that different coil sets have similar or even the same matching impedance to ground, which is not limited in this application. ,

Fig. 5a shows a cross-sectional view of a common mode filter according to an embodiment of the present application, and Fig. 5b shows a schematic structural diagram of a common mode filter according to an embodiment of the present application. Fig. 5a is a cross-sectional view obtained by cutting along the position of the dotted frame area s3 in 1c. In order to facilitate the understanding of the wiring layout of the coil group in this application, only the part related to the coil group is shown in cross-section Fig. 5a . In a possible implementation manner, as shown in Fig. 5a and Fig. 5b, the reference ground structure may include a first auxiliary layer 31 and a second auxiliary layer 32. The first auxiliary layer 31 is located between the first coil layer 21 and the first magnetic layer 11 , and the first auxiliary layer 31 is isolated from the first coil layer 21 by an insulating medium to prevent the first auxiliary layer 31 It is electrically connected to the first coil layer 21 . The first auxiliary layer 31 is provided with a first reference ground wire 41 corresponding to the first wire a, the second wire b, and the third wire c in the first coil layer 21 , namely, the first reference ground wire 41 . The reference ground wire 41 includes: the reference ground wire segment Da of the first trace a in the first coil layer 21 , the reference ground wire segment Db of the second trace b in the first coil layer 21 , and the first coil layer 21 The reference ground segment Dc of the third trace c. The second auxiliary layer 32 is located between the second coil layer 22 and the second magnetic layer 12. Similarly, the second auxiliary layer 32 is separated from the second coil layer 22 by an insulating medium to prevent the second auxiliary layer 32 is electrically connected to the second coil layer 22 . The second auxiliary layer 32 is provided with a second reference ground wire 42 corresponding to the first wire a, the second wire b, and the third wire c in the second coil layer 22 , namely the second reference ground wire 42 . The reference ground wire 42 includes: the reference ground wire segment Fa of the first trace a in the second coil layer 22 , the reference ground wire segment Fb of the second trace b in the second coil layer 22 , and the second coil layer 22 The reference ground segment Fc of the third trace c.

In this implementation, the first auxiliary layer 31 and the second auxiliary layer 32 can be electrically connected through auxiliary layer vias; the first auxiliary layer 31 and the second auxiliary layer 32 can also be "suspended" between the magnetic layer and the coil layer , that is, the two do not need to be electrically connected. When electrically connected through the auxiliary layer vias, the auxiliary layer vias cannot be electrically connected to any traces and trace vias in the coil layer.

Among them, for the convenience of describing the arrangement of the first auxiliary layer 31 and the second auxiliary layer 32 in the common mode filter, only “FIG. 3a and FIG. 3b” are used as examples to describe the addition of the first auxiliary layer 31 in FIGS. 5a and 5b. and the arrangement of the second auxiliary layer 32, those skilled in the art can, according to the arrangement of the first auxiliary layer 31 and the second auxiliary layer 32 in FIG. 5a and FIG. The first auxiliary layer 31 and the second auxiliary layer 32 are added to the common mode filter of , which will not be repeated here.

In this implementation, as shown in FIG. 5a and FIG. 5b , the positions and layouts of the reference ground segments in the first reference ground wire 41 and the second reference ground wire 42 are the same as the positions and layouts of their corresponding traces, so that Ensure that different coil groups have similar ground impedance.

By setting the common mode filter as shown in Fig. 5a and Fig. 5b, the distances between all coil groups and the first magnetic layer and the second magnetic layer are kept the same under the same phase; The common mode filter set by adding the first auxiliary layer and the second auxiliary layer (that is, the corresponding ways of Fig. 2a, Fig. 2b, Fig. 4, etc.) The layers make different coil groups have similar impedance to ground, which further improves the symmetry between different coil groups and reduces the longitudinal transfer loss of the common mode filter.

2a, 2b, 3a, 3b, and 4 provide several common-mode filters, Figures 6a and 6b show cross-sectional views of a common-mode filter according to an embodiment of the present application , FIG. 6c shows a schematic structural diagram of a common mode filter according to an embodiment of the present application. Figures 6a and 6b are cross-sectional views obtained by cutting along the position of the dotted frame area s3 in Figure 1f. In order to facilitate the understanding of the wiring layout of the coil set in this application, only the cross-sectional views shown in Figures 6a and 6b are shown. out the part related to the coil set. In a possible implementation manner, as shown in FIG. 6a, FIG. 6b, and FIG. 6c, the reference ground structure may include: a first accompanying reference ground wire, a middle accompanying reference ground wire, and a second accompanying reference ground wire, so The first accompanying reference ground line 51 of one or more of the first trace a, the second trace b, and the third trace c of the first coil layer 21 is arranged in the first coil layer 21 . , the first accompanying reference ground line 51 is located on one side or both sides of the first target line. The intermediate coil layer 23 is provided with a reference ground line 53 in the middle of one or more intermediate target traces among the first trace a, the second trace b, and the third trace c of the intermediate coil layer 23 . , the middle accompanying reference ground line 53 is located on one side or both sides of the middle target line. The second coil layer 22 is provided with a second companion of one or more second target traces among the first trace a, the second trace b, and the third trace c of the second coil layer 22 The reference ground line 52, the second accompanying reference ground line 52 is located on one side or both sides of the second target trace. Wherein, the material of the first accompanying reference ground wire, the middle accompanying reference ground wire, and the second accompanying reference ground wire may be the same metal as the material of the trace, or may be different metals.

6a and 6c only show that the first accompanying reference ground 51 is provided on one side (outside) of the first trace a, the second trace b, and the third trace c of the first coil layer 21, and also That is, the first trace a, the second trace b, and the third trace c of the first coil layer 21 are the first target traces; the first trace a, the second trace b, One side (outside) of the third trace c is provided with a second accompanying reference ground trace 52, that is, the first trace a, the second trace b, and the third trace c of the second coil layer 22 are the second target traces line; set the middle accompanying reference ground line 53 on one side (outside) of the first line a, the second line b, and the third line c of the middle coil layer 23, that is, the first line of the middle coil layer 23 a. The second line b and the third line c are the middle target lines. FIG. 6b only shows that the first accompanying reference ground 51 is provided on both sides of the first trace a, the second trace b, and the third trace c of the first coil layer 21 , that is, the first coil layer 21 The first trace a, the second trace b, and the third trace c are the first target traces; two of the first trace a, the second trace b, and the third trace c on the second coil layer 22 A second accompanying reference ground wire 52 is provided on the side, that is, the first trace a, the second trace b, and the third trace c of the second coil layer 22 are the second target traces; The intermediate reference ground line 53 is set on both sides of the trace a, the second trace b, and the third trace c, that is, the first trace a, the second trace b, and the third trace c of the middle coil layer 23 Run the line for the intermediate target. For the settings of the first accompanying reference ground wire 51, the second accompanying reference ground wire 52, and the intermediate accompanying reference ground wire 53 in other ways, the layout can be made with reference to the examples given in FIGS. 6a, 6b, and 6c. This will not be repeated here.

In this implementation, in the actual wiring process, the common mode filter that needs to be satisfied according to the layout settings of the first wiring, the second wiring, and the third wiring in different coil layers, along with the setting of the reference ground wire Use requirements, set the position of the accompanying reference ground wire in each coil layer, the number of accompanying traces, which one of the accompanying first trace, second trace, and third trace, and also That is, the setting conditions of the accompanying reference ground wires in different coil layers may be the same or different. In this way, the symmetry of the different coil groups can be improved, and the different coil groups have similar impedances to ground. Those skilled in the art can determine whether the first, second, and third traces in each coil layer are set with reference ground, one side or both sides, inside or outside, etc. according to actual needs. adjustment, which is not limited in this application.

For example, assume that the multiple coil layers are: Layer 1, Layer 2... Layer 6, where "Layer 1" is the first coil layer, "Layer 2-5" is the Layer 6" is the second coil layer. Then, in "Layer 1", the first accompanying reference ground wire 51 can be set only on one side of the first trace a, and in the "Layer 2", the intermediate accompanying reference ground wire can be set only on both sides of the first trace a. 53. In the "3rd layer", the intermediate reference ground line 53 can be set only on both sides of the first trace a and the second trace b. In the "4th layer", only the first trace a, the second trace The middle and reference ground lines 53 are arranged on both sides of the second line b and the third line c. In the "5th layer", the center can be set only on the outside of the first line a, the second line b, and the third line c. Along with the reference ground line 53 , the second accompanying reference ground line 52 may be provided only inside the first line a, the second line b, and the third line c in the “6th layer”.

By setting the common mode filter as shown in Fig. 6a, Fig. 6b, Fig. 6c, all the coil groups keep the same distance from the first magnetic layer and the second magnetic layer under the same phase, and compared with Fig. 4, etc. Add a common mode filter set in the manner of the accompanying reference ground line (that is, the corresponding manners in Figure 2a, Figure 2b, Figure 3a, Figure 3b, etc.), by setting the first accompanying reference ground wire, the second accompanying reference ground wire, the middle With the reference ground wire, different coil groups have similar ground impedances, and further improve the symmetry between different coil groups and reduce the longitudinal transfer loss of the common mode filter.

In a possible implementation manner, the accompanying reference ground wires in different coil layers may be connected together, that is, the first accompanying reference ground wire, the intermediate accompanying reference ground wire and the second accompanying reference ground wire The ground wires are connected together or not. Some or all of the first accompanying reference ground wire, the middle accompanying reference ground wire and the second accompanying reference ground wire may be connected together or not connected together according to the ground impedance of different coil groups. When the connection between the first accompanying reference ground wire, the intermediate accompanying reference ground wire and the second accompanying reference ground wire is required, the connection between the accompanying reference ground wires can be realized by setting vias in the corresponding coil layers, or external Set the wires to realize the connection between the first accompanying reference ground wire, the middle accompanying reference ground wire and the second accompanying reference ground wire. The material of the first companion ground reference, the middle companion ground reference and the second companion ground reference may be metal. In this way, compared with not connecting the first accompanying reference ground wire, the middle accompanying reference ground wire and the second accompanying reference ground wire together, it can further ensure that different coil groups have similar ground impedances.

In a possible implementation manner, the reference ground structure may include at least one of the following metal reference ground layers:

The first metal reference ground layer is located between the first coil layer and the first magnetic layer.

A second metal reference ground layer is located between the second coil layer and the second magnetic layer.

A third metal reference ground layer is located between the first coil layer and the intermediate coil layer, and is provided with a first wiring via hole, a second wiring via hole, The first accommodating hole of the third wiring via.

The fourth metal reference ground layer is located between the second coil layer and the middle coil layer, and is provided with a first wiring via hole, a second wiring via hole, The second accommodating hole of the third wiring via.

an intermediate metal reference ground layer, the intermediate metal reference ground layer includes one or more, each intermediate metal reference ground layer is located between two intermediate coil layers, and is provided with a first trace accommodating through the third metal reference ground layer The third accommodating hole of the via hole, the second wiring via hole, and the third wiring via hole.

In this implementation manner, the number and type of the metal reference ground layers can be determined according to the magnitude of the difference in impedance to ground between different coil groups after different types of metal reference ground layers are set. For example, on the basis of several common-mode filters provided in the above-mentioned FIGS. 2a, 2b, 3a, 3b, and 4, FIG. 7a shows a cross-section of a common-mode filter according to an embodiment of the present application FIG. 7b shows a schematic structural diagram of a common mode filter according to an embodiment of the present application. Fig. 7a is a cross-sectional view obtained by cutting along the position of the dotted frame area s3 in Fig. 1f. In order to facilitate the understanding of the wiring layout of the coil assembly in the present application, only the cross-sectional view related to the coil assembly is shown in Fig. 7a. part. As shown in Figure 7a and Figure 7b, the common mode filter includes a total of 6 coil layers of "Layer 1, Layer 2... "5th layer" is the middle coil layer, and "6th layer" is the second coil layer. The reference ground structure includes a first metal reference ground layer 61 , a second metal reference ground layer 62 , a third metal reference ground layer 63 , a fourth metal reference ground layer 64 and three intermediate metal reference ground layers 65 . Wherein, the third metal reference ground layer 63 is further provided with a first wiring via hole, a second wiring via hole, a third wiring via hole corresponding to the realization of "the wiring connection of the coil set between the first layer and the second layer" The first accommodating hole 630 of the wire via. The fourth metal reference ground layer 64 is also provided with a first wiring via hole, a second wiring via hole, and a third wiring via hole corresponding to the realization of "the wiring connection of the coil group between the fifth layer and the sixth layer". The second accommodating hole 640 of the hole. The three intermediate metal reference ground layers 65 are also provided with corresponding lines corresponding to "the wiring connection of the coil group between the second layer and the third layer", "the wiring connection of the coil group between the third layer and the fourth layer", "the first layer". The first wiring via hole, the second wiring via hole, and the third wiring via hole 650 for the wiring connection of the coil group between the 4th layer and the 5th layer.

As shown in FIG. 7b, a same accommodating hole (the accommodating hole is the above-mentioned first accommodating hole) can be provided for the first wiring via hole, the second wiring via hole, and the third wiring via hole passing through the metal reference ground layer. , the second accommodating hole or the third accommodating hole), the accommodating hole can accommodate the first wiring via hole, the second wiring via hole, and the third wiring via hole at the same time. Alternatively, a corresponding accommodating hole can be set for each routing via. The accommodating hole and the routing via hole it accommodates are insulated from each other, which can be achieved by means of dielectric insulation and physical spacing. In this way, the traces of different coil groups in different coil layers will not be connected together because they are in contact with the metal reference ground layer, so as to ensure mutual insulation between different coil groups.

By setting the common mode filter in the manner shown in Fig. 7a and Fig. 7b, all the coil groups keep the same distance from the first magnetic layer and the second magnetic layer in the same phase. For common mode filters set in the manner of adding a metal reference ground layer (that is, the methods corresponding to Figure 3a, Figure 3b, Figure 4, etc.), by setting at least one metal reference ground layer, different coil sets have similar grounding impedance, and further improve the symmetry between different coil sets and reduce the longitudinal transfer loss of the common mode filter.

In a possible implementation manner, when there are multiple metal reference ground layers, the multiple metal reference ground layers are connected together through a reference ground via hole, and the reference ground via hole is provided in the first coil layer , in one or more of the second coil layer and the intermediate coil layer, the number of the reference ground via holes may be one or more.

In this implementation manner, FIG. 7c shows a schematic structural diagram of a common mode filter according to an embodiment of the present application. The difference between the common mode filter shown in Fig. 7c and the common mode filter shown in Fig. 7b and Fig. 7a is that the common mode filter shown in Fig. 7c is provided with a reference ground via 212 in the coil layer. The number and size of the reference ground vias 212 can be set as required, which is not limited in this application. By setting reference ground vias, the difference in impedance to ground between different coil sets can be further reduced on the basis of the common mode filter shown in Figure 7b and Figure 7a.

In this implementation, the metal reference stratum is set with spatial dimensions such as thickness, length, and width, and the metal reference stratum can be determined according to the limitations of the processing technology, longitudinal transfer loss, differential mode loss, return loss, impedance index parameters, etc. The thickness, length, and width of the metal reference layer are set. In FIG. 7b and FIG. 7c, in order to more clearly indicate the position of the metal reference layer, only the “surface” is used to indicate the metal reference layer, and its thickness is not shown.

FIG. 8a shows a schematic structural diagram of a common mode filter according to an embodiment of the present application. FIG. 8b shows a cross-sectional view of a common mode filter according to an embodiment of the present application, and FIG. 8b is a cross-sectional view obtained by cutting along the position of the dotted frame area s4 in FIG. Only the part related to the coil group is shown in the cross-sectional Figure 8b. In a possible implementation manner, as shown in Figures 8a and 8b, the common mode filter may further include a third magnetic layer 13 and a fourth magnetic layer 14 that are parallel to each other. The first coil layer 21 , the intermediate coil layer 23 , and the second coil layer 22 are located between the third magnetic layer 13 and the fourth magnetic layer 14 , and the third magnetic layer 13 is respectively Perpendicular to the first magnetic layer 11 and the second magnetic layer 12 , and the fourth magnetic layer 14 are perpendicular to the first magnetic layer 11 and the second magnetic layer 12 , respectively.

In this implementation manner, the fourth magnetic layer and the third magnetic layer are set with spatial dimensions such as thickness, length, and width, and can be set according to the limitations of the processing technology, longitudinal transfer loss, differential mode loss, return loss, and impedance indicators The thickness, length, and width of the fifth magnetic layer and the sixth magnetic layer are set by parameters, etc. In FIG. 8a, the positions of the third magnetic layer and the fourth magnetic layer are more clearly indicated, and the third magnetic layer is only represented by "plane" , the fourth magnetic layer, the thickness of which is not shown. The materials of the fourth magnetic layer and the third magnetic layer can be magnetic materials such as ferrite, and the materials of the third magnetic layer and the fourth magnetic layer can be the same as or different from the materials of the first magnetic layer and the second magnetic layer. There are no restrictions on the application.

By setting the common mode filter as shown in Fig. 8a and Fig. 8b, the distances between all coil groups and the first magnetic layer, the second magnetic layer, the third magnetic layer, and the fourth magnetic layer are kept the same in the same phase, and the phase Compared with Fig. 1h and other common-mode filters that only provide the first magnetic layer and the second magnetic layer (as shown in Fig. 2a-Fig. 2b, Fig. 4, etc.), multiple coil groups can be in the same two dimensions. The magnetic environment can further improve the symmetry between different coil groups and reduce the longitudinal transfer loss of the common mode filter.

FIG. 9a shows a schematic structural diagram of a common mode filter according to an embodiment of the present application. FIG. 9b shows a cross-sectional view of a common mode filter according to an embodiment of the present application, and FIG. 9b is a cross-sectional view obtained by cutting along the position of the dotted frame area s2 in FIG. Only the part related to the coil group is shown in the cross-sectional Figure 9b. In a possible implementation manner, as shown in FIG. 9a and FIG. 9b , when the common mode filter includes the third magnetic layer 13 and the fourth magnetic layer 14 that are parallel to each other, the common mode filter may also include a third magnetic layer 13 and a fourth magnetic layer that are parallel to each other. the fifth magnetic layer 15 and the sixth magnetic layer 16. The first coil layer 21 , the intermediate coil layer 23 , and the second coil layer 22 are located between the fifth magnetic layer 15 and the sixth magnetic layer 16 , and the fifth magnetic layer 15 is respectively perpendicular to the first magnetic layer 11 , the second magnetic layer 12 , the third magnetic layer 13 and the fourth magnetic layer 14 , the sixth magnetic layer 16 is perpendicular to the first magnetic layer 11. The second magnetic layer 12 , the third magnetic layer 13 and the fourth magnetic layer 14 .

In this implementation manner, the fifth magnetic layer and the sixth magnetic layer are set with spatial dimensions such as thickness, length, and width, and can be set according to the limitations of the processing technology, longitudinal transfer loss, differential mode loss, return loss, and impedance indicators The thickness, length, and width of the fifth magnetic layer and the sixth magnetic layer are set by parameters, etc. In FIG. 9a, the fifth magnetic layer is only represented by “plane” in order to illustrate the positions of the fifth and sixth magnetic layers more clearly. , the sixth magnetic layer, the thickness of which is not shown. The materials of the fifth magnetic layer and the sixth magnetic layer can be magnetic materials such as ferrite, and the materials of the fifth magnetic layer and the sixth magnetic layer can be the same as the first magnetic layer and the second magnetic layer, the third magnetic layer and the The materials of the four magnetic layers are the same or different, which is not limited in this application.

In this implementation manner, lead-out via holes for the electrodes of the common mode filter may be provided in the first magnetic layer, the second magnetic layer, the third magnetic layer, the fourth magnetic layer, the fifth magnetic layer, and the sixth magnetic layer, It is convenient for the common mode filter to be assembled and electrically connected in the circuit system. Those skilled in the art can set the position and size of the lead-out via hole as required, which is not limited in this application.

The common mode filter is set in the manner of Fig. 9a and Fig. 9b, so that all coil sets are in the same phase with the first magnetic layer, the second magnetic layer, the third magnetic layer, the fourth magnetic layer, the fifth magnetic layer and the sixth magnetic layer The distances of the magnetic layers are kept the same respectively, and compared with the method of Fig. 1h, only the first magnetic layer and the second magnetic layer are arranged (as shown in Fig. 2a-Fig. 2b, Fig. 4, etc.). The coil group can be in the same magnetic environment in the three-dimensional space, which further improves the symmetry between different coil groups and reduces the longitudinal transfer loss of the common mode filter.

In a possible implementation manner, the reference ground structure may include a metal reference ground cladding layer, and the metal reference ground cladding layer coats the surface of the common mode filter. Metallic reference ground cladding is used to clad the components included in the common mode filter above. The common mode filter is set by adding a metal reference ground cladding layer, so that the distances between all coil groups and the magnetic layer are kept the same under the same phase, and compared with Fig. 1h without the metal reference ground cladding layer (such as 2a-2b, Fig. 4, etc.), the common mode filter is set up, so that multiple coil groups can be in the same reference ground environment and the same impedance to ground in the three-dimensional space, which further improves the relationship between different coil groups. The symmetry reduces the vertical transfer loss of the common mode filter.

For example, FIG. 10a shows a schematic structural diagram of a common mode filter according to an embodiment of the present application. Fig. 10b shows a cross-sectional view of a common mode filter according to an embodiment of the present application, and Fig. 10b is a cross-section obtained by cutting along the position of the dotted frame area s2 in Fig. 1e (or the dotted frame area s4 in Fig. 1g ). In the figure, in order to facilitate the understanding of the wiring layout of the coil assembly in the present application, only the part related to the coil assembly is shown in the cross-sectional view 10b. In a possible implementation manner, as shown in FIGS. 10a and 10b , the metal reference ground cladding layer 71 is used to coat the first magnetic layer 11 , the second magnetic layer 12 and the multiple coil layer.

FIG. 11a shows a schematic structural diagram of a common mode filter according to an embodiment of the present application. 11b shows a cross-sectional view of a common mode filter according to an embodiment of the present application, and FIG. 11b is a cross-sectional view obtained by cutting along the position of the dotted frame area s2 in FIG. Only the part related to the coil group is shown in the cross-sectional view 11b. In a possible implementation manner, as shown in FIGS. 11a and 11b , the metal reference ground cladding layer 71 is used to coat the first magnetic layer 11 , the second magnetic layer 12 , and the third magnetic layer 71 . layer 13 , the fourth magnetic layer 14 , the fifth magnetic layer 15 , the sixth magnetic layer 16 , the plurality of coil layers.

In this implementation, when the reference ground structure includes parts such as the metal reference ground layer, the first auxiliary layer and the second auxiliary layer, these parts also need to be covered by the metal reference ground cladding layer 71 .

In this implementation, the metal reference ground cladding layer, the first magnetic layer 11 , the second magnetic layer 12 , the third magnetic layer 13 , the fourth magnetic layer 14 , the fifth magnetic layer 15 , and the sixth magnetic layer In 16, the lead-out holes of the common-mode filter electrodes are arranged to facilitate the assembly and electrical connection of the common-mode filter in the circuit system. Those skilled in the art can set the position and size of the lead-out holes as required. No restrictions apply.

In this implementation manner, the metal reference ground cladding layer has a thickness setting, and the metal reference ground cladding layer can be adjusted according to the limitations of the processing technology, longitudinal transfer loss, differential mode loss, return loss, impedance index parameters, etc. The thickness is set, which is not limited in this application.

Fig. 12a shows a perspective view of a common mode filter according to an embodiment of the present application, and Fig. 12b shows a front view of the common mode filter according to an embodiment of the present application. Figure 12c shows a side view of a common mode filter according to an embodiment of the present application. FIG. 12d shows a top view of a common mode filter according to an embodiment of the present application. FIG. 13a shows a perspective view of a common mode filter according to an embodiment of the present application, and FIG. 13b shows a front view of the common mode filter according to an embodiment of the present application. Figure 13c shows a side view of a common mode filter according to an embodiment of the present application. Figure 13d shows a top view of a common mode filter according to an embodiment of the present application. In a possible implementation manner, as shown in FIGS. 12a-12d and 13a-13d, the reference ground structure may further include a The pads 81(s) of the terminals and the metal reference ground strips 91. Wherein, one end of the two ends of the traces located in the first coil layer in each coil group that is not connected to the traces of the same coil group in other coil layers is a terminal of the coil group, and one end of each coil group located in the first coil group is located in the first coil group. One end of the two ends of the wires in the second coil layer that is not connected to the wires of the same coil group in the other coil layers is the other terminal of the coil group. For example, one end of the two ends of the first wire located in the first coil layer in the first coil group that is not connected to the first wire in the intermediate coil layer is a terminal of the first coil group; in the first coil group One end of the two ends of the first wire in the second coil layer that is not connected to the first wire in the middle coil layer is the other terminal of the first coil group.

A part of each pad 81 is located on the first side of the common-mode filter (ie, the bottom surface of the common-mode filter in FIGS. 12a-12d and 13a-13d ), and another part of each pad 81 is located on the first side of the common-mode filter. One of multiple second side surfaces connected to the first side surface of the common mode filter (that is, the side surfaces connected to the bottom surface of the common mode filter in FIGS. 12a-12d and 13a-13d), so The metal reference ground strip 91 is located between the plurality of bonding pads 81 and surrounds at least part of the first side surface of the common mode filter and the second side surface with bonding pads.

In this implementation, as shown in the examples shown in Fig. 12a-Fig. 12d and Fig. 13a-Fig. 13d, it is assumed that the common mode filter has 3 coil groups and 6 pads 81, and each of the 6 pads 81 is partially located in The bottom surface (ie, the first side) of the common mode filter, and the other part of three of the six pads 81 (hereinafter referred to as the first group of pads) are located on the front side of the common mode filter that is connected to the bottom surface. (that is, the second side), the other part of the other three pads 81 (hereinafter referred to as the second group of pads) among the six pads 81 is located on the side directly behind the common mode filter connected to the bottom surface (that is, the second side). As shown in FIGS. 12a-12d, the metal reference ground strip 91 may only be located between the first group of pads and the second group of pads, that is, a part of the metal reference ground strip 91 is in the middle area of the first side and Passing through the first set of pads and the second set of pads, the other parts of the metal reference ground strip 91 are located on the left side and the right side of the common mode filter, respectively, and the metal reference ground strip 91 is on the left side and The height of the part on the right side is at least equal to the height of the pad 81 on the front side and the rear side, so as to ensure that each pad can use the metal reference ground strip as a reference ground. As shown in Figures 13a-13d, the metal reference ground strip 91 continues to extend around the entire common mode filter on the basis of Figures 12a-12d to ensure that each pad can connect the metal reference ground strip as a reference point.

In this implementation manner, the metal reference ground strip is set in thickness and width, and the metal reference ground cladding layer can be clad according to the limitations of the processing technology, longitudinal transfer loss, differential mode loss, return loss, impedance index parameters, etc. The thickness is set, which is not limited in this application.

12a-12d and 13a-13d are used to set the common mode filter, so that the distances between all coil groups and the magnetic layer are kept the same under the same phase, and compared with the common mode filter set in the way of Fig. 1h , so that different coil groups have similar ground impedances at the pad positions, which further improves the symmetry between different coil groups and reduces the longitudinal transfer loss of the common mode filter.

Fig. 14a shows a cross-sectional view of a common mode filter according to an embodiment of the present application, and Fig. 14b shows a schematic diagram of a plurality of coil layers of the common mode filter according to an embodiment of the present application. Fig. 14a is a cross-sectional view obtained by cutting along the position of the dotted frame area s3 in Fig. 1f. In order to facilitate the understanding of the wiring layout of the coil group in the present application, only the cross-sectional view related to the coil group is shown in the cross-section Fig. 14a. part. In a possible implementation, the common mode filter shown in Fig. 14a and Fig. 14b is the same as the above-mentioned Figs. 2a-2b, 3a-3b, 4, 5a-5b, 6a-6c , Figures 7a-7c, 8a-8b, 9a-9b, 10a-10b, 11a-11b, 12a-12d, 13a-13d The common mode filter shown in 14b includes four coil groups, the plurality of coil groups further includes a fourth coil group D, and the plurality of routing vias further includes a fourth routing via (in the figure). (not shown, see FIG. 2b and the arrangement of the wiring via holes in the related text description), each fourth coil group D includes the fourth wiring d in the first coil layer 21, the second coil layer 22 The fourth wiring d in the middle coil layer 23 and the fourth wiring d in the middle coil layer 23 . A plurality of traces of the fourth coil group D are connected together through the fourth trace via holes, and the first trace a, the second trace b, the third trace c and the fourth trace in the same coil layer Trace d is wound in parallel.

Among them, as shown in Figure 14b, in each coil layer, the traces marked "a", "b", "c", and "d" are the first trace and the second trace of the coil layer where they are located, respectively. , the third line and the fourth line, that is, the first line is "a", the second line is "b", the third line is "c", and the fourth line is "d". The multiple traces of the first coil group A are the first coil layer "Layer 1", the multiple intermediate coil layers "Layer 2 to Layer 5", and the second coil layer "Layer 6" marked as " a" trace. The multiple traces of the second coil group B are the first coil layer "Layer 1", the multiple intermediate coil layers "Layer 2 to Layer 5", and the second coil layer "Layer 6" marked as " b" trace. The multiple traces of the third coil group C are the first coil layer "Layer 1", the multiple intermediate coil layers "Layer 2 to Layer 5", and the second coil layer "Layer 6" marked as " c" trace. The multiple traces of the fourth coil group D are the first coil layer "Layer 1", the multiple intermediate coil layers "Layer 2 to Layer 5", and the second coil layer "Layer 6" marked as " d" trace.

In this implementation, the four coil groups can be adjusted with reference to the common mode filter shown in FIG. 14a and FIG. 14b above, other parts (such as metal reference ground cladding layers, etc.) are added, and the The layout of the traces is not limited in this application. The number of coil groups, the thickness, width, and spacing of the wiring of the coil group can be set according to device requirements, processing technology limitations, etc., which are not limited in this application.

By setting the common mode filter in the way of Fig. 14a and Fig. 14b, the distances between all coil groups and the magnetic layer are kept the same in the same phase. Compared with Fig. 1h, there are only three coil groups (Fig. 2a-Fig. 2b). , Figure 4, etc.) common mode filter, while increasing the number of coil groups in the common mode filter, the symmetry between different coil groups is improved, and the longitudinal transfer loss of the common mode filter is reduced.

Various embodiments of the present application have been described above, and the foregoing descriptions are exemplary, not exhaustive, and not limiting of the disclosed embodiments. Numerous modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The embodiments of the present application and features in the embodiments may be combined with each other without conflict. The terminology used herein was chosen to best explain the principles of the embodiments, the practical application or improvement over the technology in the marketplace, or to enable others of ordinary skill in the art to understand the embodiments disclosed herein.

Claims (19)

1. A common mode filter, comprising: the coil comprises a plurality of coil groups, a plurality of routing through holes, a first magnetic layer, a second magnetic layer and a plurality of coil layers which are parallel to each other, wherein the plurality of coil groups at least comprise a first coil group, a second coil group and a third coil group;

the first coil layer, the intermediate coil layer and the second coil layer are sequentially stacked between the first magnetic layer and the second magnetic layer;

the first coil group comprises a first trace in each of the coil layers, the second coil group comprises a second trace in each of the coil layers, and the third coil group comprises a third trace in each of the coil layers;

the first trace via hole is used for connecting a plurality of first traces of the first coil group together, the second trace via hole is used for connecting a plurality of second traces of the second coil group together, and the third trace via hole is used for connecting a plurality of third traces of the third coil group together;

at least two of the first wire, the second wire and the third wire in the same coil layer are wound in parallel.

2. A common-mode filter, comprising: the coil comprises a plurality of coil groups, a plurality of routing through holes, and a first magnetic layer, a second magnetic layer and a plurality of coil layers which are parallel to each other, wherein the plurality of coil groups at least comprise a first coil group, a second coil group and a third coil group, the plurality of routing through holes at least comprise a first routing through hole, a second routing through hole and a third routing through hole, the plurality of coil layers comprise a first coil layer, at least one middle coil layer and a second coil layer, each coil layer is at least provided with a first routing, a second routing and a third routing,

the first coil layer, the middle coil layer and the second coil layer are sequentially arranged between the first magnetic layer and the second magnetic layer; the first coil group comprises a first trace in each coil layer, the second coil group comprises a second trace in each coil layer, and the third coil group comprises a third trace in each coil layer;

the first trace via hole is used for connecting a plurality of first traces of the first coil group together, the second trace via hole is used for connecting a plurality of second traces of the second coil group together, and the third trace via hole is used for connecting a plurality of third traces of the third coil group together;

at least two of the first wire, the second wire and the third wire in the same coil layer are wound in parallel, and the width of the same coil group meets any one of the following conditions:

the width of the first wire and the width of the second wire are both the width of the first wire, the width of the third wire is the width of the second wire, and the width of the first wire is different from the width of the second wire; or,

the width of the first wire, the width of the second wire and the width of the third wire are different, wherein the width of the first wire is the width of the first wire, and the width of the second wire is the width of the second wire.

3. A common-mode filter according to claim 2,

the first trace width and the second trace width satisfy:

w1 is p1 xW 2, W1 is the first trace width, W2 is the second trace width, and p1 is a proportionality coefficient, wherein p1 is E [0.5,0.8] or p 1E [2,3 ].

4. The common mode filter according to any one of claims 1 to 3, wherein the first trace, the second trace and the third trace in the first coil layer have a first relative positional relationship therebetween, the first trace, the second trace and the third trace in the second coil layer have a second relative positional relationship therebetween, the first trace, the second trace and the third trace in the intermediate coil layer have an intermediate relative positional relationship therebetween,

the first relative position relationship, the second relative position relationship and the middle relative position relationship are the same, and the center lines of the first routing via hole connected with the first routing, the second routing via hole connected with the second routing and the third routing via hole connected with the third routing in the adjacent coil layers are all located on the same cross section perpendicular to each coil layer.

5. A common-mode filter according to any one of claims 1 to 3,

the first wire, the second wire and the third wire in the first coil layer have a first relative position relationship, the first wire, the second wire and the third wire in the second coil layer have a second relative position relationship, the first wire, the second wire and the third wire in the middle coil layer have a middle relative position relationship,

the first relative position relationship, the second relative position relationship and the middle relative position relationship are the same, and the sum of the first lengths of the first wires of the first coil group, the sum of the second lengths of the second wires of the second coil group and the sum of the third lengths of the third wires of the third coil group are the same.

6. The common mode filter according to any one of claims 1 to 3, wherein the first trace, the second trace and the third trace in the first coil layer have a first relative positional relationship therebetween, the first trace, the second trace and the third trace in the second coil layer have a second relative positional relationship therebetween, the first trace, the second trace and the third trace in the intermediate coil layer have an intermediate relative positional relationship therebetween,

the first relative position relationship, the second relative position relationship and the middle relative position relationship are not consistent, and the sum of the first lengths of the first wires of the first coil group, the sum of the second lengths of the second wires of the second coil group and the sum of the third lengths of the third wires of the third coil group are the same.

7. A common-mode filter according to any one of claims 1 to 6, characterized in that the common-mode filter further comprises at least one ground reference structure, the ground reference structure is insulated from each first trace, each second trace and each third trace, and the ground reference structure is insulated from the first magnetic layer and the second magnetic layer.

8. A common-mode filter according to claim 7, characterized in that the ground reference structure comprises a first auxiliary layer and a second auxiliary layer,

the first auxiliary layer is positioned between the first coil layer and the first magnetic layer, and first reference ground wires corresponding to a first wire, a second wire and a third wire in the first coil layer are arranged in the first auxiliary layer;

the second auxiliary layer is located between the second coil layer and the second magnetic layer, and second reference ground wires corresponding to the first wire, the second wire and the third wire in the second coil layer are arranged in the second auxiliary layer.

9. A common-mode filter according to claim 6 or 7, characterized in that the ground reference structure comprises: a first companion ground reference line, an intermediate companion ground reference line and a second companion ground reference line,

the first coil layer is provided with a first accompanying reference ground wire of one or more first target wires of the first wire, the second wire and the third wire of the first coil layer, and the first accompanying reference ground wire is positioned at one side or two sides of the first target wires;

the middle coil layer is provided with a middle accompanying reference ground wire of one or more middle target wires in the first wire, the second wire and the third wire of the middle coil layer, and the middle accompanying reference ground wire is positioned at one side or two sides of the middle target wires;

the second coil layer is provided with a second accompanying reference ground wire of one or more second target wires of the first wire, the second wire and the third wire of the second coil layer, and the second accompanying reference ground wire is positioned on one side or two sides of the second target wires.

10. A common-mode filter according to claim 9, characterized in that the first, intermediate and second companion ground reference lines are connected together.

11. A common-mode filter according to any one of claims 7 to 10, characterized in that the reference ground structure comprises at least one of the following metal reference ground layers:

a first metal reference ground layer between the first coil layer and the first magnetic layer;

a second metal reference ground layer between the second coil layer and the second magnetic layer;

the third metal reference stratum is positioned between the first coil layer and the middle coil layer and is provided with a first accommodating hole for accommodating a first routing through hole, a second routing through hole and a third routing through hole which pass through the third metal reference stratum;

the fourth metal reference stratum is positioned between the second coil layer and the middle coil layer and is provided with a first routing through hole, a second routing through hole and a second containing hole for containing the third routing through hole which pass through the third metal reference stratum;

the middle metal reference stratum comprises one or more middle metal reference stratums, each middle metal reference stratum is located between two middle coil layers and is provided with a first routing through hole, a second routing through hole and a third containing hole, and the first routing through hole, the second routing through hole and the third routing through hole penetrate through the third metal reference stratum.

12. A common-mode filter according to claim 11, wherein when the metal reference ground layer is plural, plural metal reference ground layers are connected together by a ground reference via provided in one or more of the first coil layer, the second coil layer and the intermediate coil layer.

13. A common-mode filter according to any one of claims 1 to 12, characterized in that the common-mode filter further comprises a third magnetic layer and a fourth magnetic layer parallel to each other,

the first coil layer, the middle coil layer and the second coil layer are located between the third magnetic layer and the fourth magnetic layer, the third magnetic layer is perpendicular to the first magnetic layer and the second magnetic layer respectively, and the fourth magnetic layer is perpendicular to the first magnetic layer and the second magnetic layer respectively.

14. A common-mode filter according to claim 13, characterized in that the common-mode filter further comprises a fifth magnetic layer and a sixth magnetic layer parallel to each other,

the first coil layer, the middle coil layer and the second coil layer are located between the fifth magnetic layer and the sixth magnetic layer, the fifth magnetic layer is perpendicular to the first magnetic layer, the second magnetic layer, the third magnetic layer and the fourth magnetic layer respectively, and the sixth magnetic layer is perpendicular to the first magnetic layer, the second magnetic layer, the third magnetic layer and the fourth magnetic layer respectively.

15. A common-mode filter according to any of claims 7 to 14, characterized in that the ground reference structure comprises a metal ground reference cladding layer, which metal ground reference cladding layer is cladded at the surface of the common-mode filter.

16. A common-mode filter according to any one of claims 7 to 14, characterized in that the ground reference structure comprises a pad and a metal ground reference strip respectively connected to the terminals of each coil group,

a part of each bonding pad is positioned on a first side face of the common mode filter, and the other part of each bonding pad is positioned on one of a plurality of second side faces connected with the first side face on the common mode filter;

the metal reference ground strip is positioned between the pads and surrounds at least partial areas of the first side and the second side with the pads of the common mode filter.

17. A common-mode filter according to any one of claims 1 to 3, characterized in that the plurality of coil groups further include a fourth coil group, the plurality of routing vias further include a fourth routing via, each coil layer is further provided with a fourth routing, the fourth coil group includes a fourth routing in each coil layer, the plurality of fourth routing of the fourth coil group are connected together through the fourth routing via, and at least two of the first routing, the second routing, the third routing and the fourth routing in the same coil layer are wound in parallel.

18. A common-mode filter according to any one of claims 1 to 17, wherein the first trace, the second trace and the third trace in the same coil layer are separated by a dielectric, and different coil layers are separated by the dielectric.

19. A common-mode filter according to claim 18, characterized in that the material of the dielectric is ceramic material, and the material of the coil assembly and the trace via is metal material.

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