CN105679512B - Chip inductor and its preparation method and application - Google Patents

Abstract

The invention relates to a chip inductor and a preparation method and application thereof. A preparation method of a chip inductor comprises the following steps: forming a first ferrite substrate body layer with a first electrode groove on the first ferrite substrate body, and forming a first electrode in the first electrode groove; forming an electrical connection on the first electrode; forming a dielectric film blank layer on the first ferrite blank layer by using ferrite slurry, wherein the electric connecting piece penetrates through the dielectric film blank layer; forming a second ferrite blank layer with a second electrode groove on the dielectric film blank layer, and forming a second electrode in the second electrode groove, wherein the second electrode is electrically connected with the electric connecting piece; laminating a second ferrite substrate blank on the second ferrite blank layer to obtain a semi-finished product; and sintering the semi-finished product to obtain the chip inductor. The preparation method of the chip inductor can effectively improve the rated current and the reliability of the chip inductor.

Description

Chip inductor and its preparation method and application

technical field

The invention relates to the manufacturing field of inductors, in particular to a chip inductor and its preparation method and application.

Background technique

Chip inductors are one of the most widely used chip components in the electronics industry. With the development of the domestic chip inductor industry, their production technology is becoming more and more mature. In order to meet people's increasing demand for components, electronic components Devices are developing in the direction of miniaturization, high frequency, high power and low power consumption.

However, the traditional chip inductor coil is directly printed on the substrate, and the coil printing has a certain thickness, so that there is a gap between the coil pattern and the substrate, and it is easy to cause bubbles to form at the connection when covering the dielectric layer, resulting in reduced product reliability. , The printing thickness of the coil is greatly limited, so that the rated current of the chip inductor is small, which cannot meet people's increasing demand for product performance.

Contents of the invention

In view of this, it is necessary to provide a preparation method capable of preparing a chip inductor with a large rated current.

In addition, a chip inductor and its application are also provided.

A method for preparing a chip inductor, comprising the steps of:

A first ferrite substrate blank is provided, a first ferrite blank layer having a first electrode groove is formed on the first ferrite substrate blank, and a first ferrite substrate layer is formed in the first electrode groove. electrode;

forming an electrical connection on the first electrode;

Using ferrite slurry to form a dielectric film base layer on the first ferrite base layer, and the dielectric film base layer shields the first ferrite base layer and the first electrode , the electrical connector is passed through the dielectric film base layer, wherein the first ferrite base layer, the first electrode, the electrical connector and the dielectric film base layer are in common Form the inductance unit;

A second ferrite base layer with a second electrode groove is formed on the dielectric film base layer, and a second electrode is formed in the second electrode groove, and the second electrode is electrically connected to the parts electrical connection;

A second ferrite substrate blank is provided, the second ferrite substrate blank is laminated on the second ferrite substrate layer, and the second ferrite substrate blank covers the second a ferrite green body layer and said second electrode to obtain a semi-finished product; and

The semi-finished product is sintered to obtain a chip inductor.

In one of the embodiments, it also includes the step of preparing the first ferrite substrate body and the second ferrite substrate body: tape-casting the soft ferrite slurry and drying to form the The first ferrite substrate blank and the second ferrite substrate blank;

Wherein, the soft ferrite slurry includes soft ferrite powder, n-propyl acetate, isobutanol, plasticizer, binder and dispersant, and the n-propyl acetate and the soft ferrite The mass ratio of the body powder is 75-85:100, and the mass ratio of the isobutanol to the soft ferrite powder is 15-20:100.

In one of the embodiments, the step of using the ferrite slurry to form the dielectric film base layer on the first ferrite base layer is specifically: coating the ferrite slurry on the layer, and making the ferrite slurry cover the first ferrite green body layer and the first electrode, exposing the electrical connector, and drying , forming the dielectric film green body layer;

Wherein, the ferrite slurry includes soft ferrite powder, n-propyl acetate, isobutanol, plasticizer, binder and dispersant, and the n-propyl acetate and the soft ferrite The mass ratio of the powder is 75-85:100, and the mass ratio of the isobutanol to the soft ferrite powder is 15-20:100.

In one of the embodiments, the step of forming the first electrode in the first electrode groove specifically includes: filling silver paste in the first electrode groove, and forming the first electrode after drying;

The step of forming the second electrode in the second electrode groove specifically includes: filling the silver paste in the second electrode groove, and forming the second electrode after drying.

In one embodiment, the step of forming the electrical connector on the first electrode specifically includes: screen printing silver paste on a part of the first electrode, and drying to obtain the electrical connector.

In one of the embodiments, the method of forming the first ferrite green body layer with the first electrode groove on the first ferrite substrate green body is screen printing; on the dielectric film The method for forming the second ferrite green body layer with the second electrode groove on the green body layer is screen printing.

In one of the embodiments, before the step of forming the second ferrite green body layer with the second electrode groove on the dielectric film green body layer, it also includes repeatedly preparing the first ferrite green body layer. Oxygen green body layer, the first electrode, the electrical connector and the dielectric film green body layer, so that a plurality of sequentially stacked inductors are formed on the first ferrite substrate green body unit, and among the two adjacent inductor units, the first ferrite base layer of one inductor unit is formed on the dielectric film base layer of the other inductor unit.

A chip inductor, comprising a first ferrite substrate, a first ferrite layer, a first electrode, a dielectric film layer, a second ferrite layer, a second electrode, an electrical connector and a second ferrite A substrate, wherein the first ferrite layer, the dielectric film layer, the second ferrite layer and the second ferrite substrate are sequentially stacked on the first ferrite substrate; A first electrode slot is opened on the first ferrite layer, and the first electrode is accommodated in the first electrode slot; a second electrode slot is opened on the second ferrite layer, and the second electrode slot is opened on the second ferrite layer. The electrodes are accommodated in the second electrode groove; the electrical connectors are penetrated through the dielectric film layer, and the electrical connectors are electrically connected to the first electrode and the second electrode; the dielectric film layer The material is ferrite, and the first ferrite layer, the first electrode, the dielectric film layer and the electrical connector together form an inductor unit.

In one of the embodiments, there are a plurality of inductance units, and the plurality of inductance units are sequentially stacked on the first ferrite substrate, and among two adjacent inductance units, one of the inductance units The first ferrite layer of the inductance unit is stacked on the dielectric film layer of the other inductance unit, and the electrical connector of one inductance unit is electrically connected with the first electrode of the other inductance unit, and the second ferrite The oxide layer is stacked on the dielectric film layer of the inductor unit farthest from the first ferrite substrate.

Application of the above-mentioned chip inductors in electronic products.

The preparation method of the above-mentioned chip inductor is simple to operate and easy to industrialized production, and the preparation method of the above-mentioned chip inductor is filled in the electrode groove by filling the electrode, so that the dielectric film green body layer and the first ferrite green body layer, The connection of the second ferrite body layer is flat, avoiding the formation of air bubbles, and the way the electrodes are filled into the electrode slots can effectively increase the thickness of the electrodes, reduce the DC resistance of the electrodes, and increase the rated current of the chip inductor and reliability.

Description of drawings

Fig. 1 is a flow chart of the preparation method of the chip inductor of an embodiment;

Fig. 2 is the exploded view of the semi-finished product prepared by the preparation method of the chip inductor shown in Fig. 1;

FIG. 3 is an exploded view of a chip inductor according to one embodiment.

detailed description

In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the associated drawings. Preferred embodiments of the invention are shown in the accompanying drawings. However, the present invention can be embodied in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided to make the understanding of the disclosure of the present invention more thorough and comprehensive.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field of the invention. The terms used herein in the description of the present invention are for the purpose of describing specific embodiments only, and are not intended to limit the present invention.

As shown in Figure 1, the preparation method of the chip inductor of an embodiment comprises the following steps:

Step S110: providing a first ferrite substrate blank, forming a first ferrite blank layer with a first electrode groove on the first ferrite substrate blank, and forming a first electrode in the first electrode groove .

Wherein, the preparation step of the first ferrite substrate body is: tape-casting the soft magnetic ferrite slurry and then drying to form the first ferrite substrate body.

Wherein, the soft ferrite slurry includes soft ferrite powder, n-propyl acetate, isobutanol, plasticizer, binder and dispersant.

Among them, the soft magnetic ferrite powder is a ferrimagnetic oxide mainly composed of Fe ₂ O ₃ , which can be produced by powder metallurgy. Before preparing soft magnetic ferrite powder, n-propyl acetate, isobutanol, plasticizer, binder and dispersant into soft ferrite slurry, first put the soft ferrite powder at 100-150°C Dry for 6-12 hours.

The mass ratio of n-propyl acetate to soft magnetic ferrite powder is 75-85:100. The mass ratio of isobutanol to soft magnetic ferrite powder is 15-20:100.

The mass ratio of the plasticizer to the soft magnetic ferrite powder is 1.5-2.5:100; the plasticizer can be a commonly used plasticizer in this field, preferably, the plasticizer is dioctyl phthalate. For example, dioctyl phthalate plasticizer under the model number DOP.

The binder may be a commonly used binder in the field, preferably, the binder is polymethyl methacrylate resin. In this embodiment, the binder is a mixture of polymethyl methacrylate resins of type B44 and A21, or a polymethyl methacrylate resin of type B44. When the binder is polymethyl methacrylate resin of model B44, the mass ratio of binder to soft ferrite powder is 20-25:100; when the binder is polymethyl methacrylate resin of model B44 and A21 For the mixture of methyl methacrylate resin, the mass ratio of binder to soft ferrite powder is 1-1.5:100.

The mass ratio of the dispersant to the soft magnetic ferrite powder is 1-1.5:100. The dispersant can be a dispersant commonly used in the art, preferably, the dispersant is polyethylene glycol octylphenyl ether. For example, polyethylene glycol octyl phenyl ether dispersant type X-100.

Wherein, the soft magnetic ferrite slurry may also be LSF-11 type high-power ferrite slurry produced by Qingdao Haopu Company.

Wherein, the drying step after tape-casting the soft ferrite slurry is: drying at 75° C. for 3.5 minutes.

Specifically, the thickness of the first ferrite substrate blank is 100-300 microns.

Wherein, the method of forming the first ferrite body layer with the first electrode groove on the first ferrite substrate body is screen printing. The slurry used to form the first ferrite green body layer is plastic ferrite slurry. For example, the plastic ferrite slurry of H-T type produced by Yinhui Electronic Materials Co., Ltd.

Wherein, the thickness of the first ferrite body layer is 40-60 microns.

Wherein, the step of forming the first electrode in the first electrode groove specifically includes: filling the first electrode groove with silver paste, and forming the first electrode after drying. For example, the silver paste can be the silver paste of SP19L type produced by Dongrong Company.

Wherein, the drying step after filling the silver paste in the first electrode tank is: drying at 70° C. for 3.5 minutes.

Step S120: forming an electrical connection on the first electrode.

Wherein, the step of forming the electrical connector on the first electrode specifically includes: screen printing silver paste on a part of the first electrode, and drying to obtain the electrical connector. For example, the silver paste can be the silver paste of SP19L type produced by Dongrong Company.

Wherein, the drying step of screen printing silver paste on part of the first electrodes is: drying at 70° C. for 3.5 minutes.

Step S130: using ferrite slurry to form a dielectric film base layer on the first ferrite base layer, and the dielectric film base layer shields the first ferrite base layer and the first electrode, and the electrical connector passes through It is arranged on the dielectric film base layer, wherein the first ferrite base layer, the first electrode, the electrical connector and the dielectric film base layer jointly form an inductor unit.

Wherein, the step of using the ferrite slurry to form the dielectric film green body layer on the first ferrite green body layer is as follows: coating the ferrite slurry on the first ferrite green body layer, and making the iron The oxide slurry shields the first ferrite body layer and the first electrode, and exposes the electrical connector, and is dried to form a dielectric film body layer.

Wherein, the ferrite slurry includes soft magnetic ferrite powder, n-propyl acetate, isobutanol, plasticizer, binder and dispersant.

Among them, the soft magnetic ferrite powder is a ferrimagnetic oxide mainly composed of Fe ₂ O ₃ , which can be produced by powder metallurgy. Before preparing soft magnetic ferrite powder, n-propyl acetate, isobutanol, plasticizer, binder and dispersant into soft ferrite slurry, first put the soft ferrite powder at 100-150°C Dry for 6-12 hours.

The mass ratio of n-propyl acetate to soft magnetic ferrite powder is 75-85:100. The mass ratio of isobutanol to soft magnetic ferrite powder is 15-20:100.

The mass ratio of the plasticizer to the soft magnetic ferrite powder is 1.5-2.5:100; the plasticizer can be a commonly used plasticizer in this field, preferably, the plasticizer is dioctyl phthalate. For example, dioctyl phthalate plasticizer under the model number DOP.

The binder may be a commonly used binder in the field, preferably, the binder is polymethyl methacrylate resin. In this embodiment, the binder is a mixture of polymethyl methacrylate resins of type B44 and A21, or a polymethyl methacrylate resin of type B44. When the binder is polymethyl methacrylate resin of model B44, the mass ratio of binder to soft ferrite powder is 20-25:100; when the binder is polymethyl methacrylate resin of model B44 and A21 For the mixture of methyl methacrylate resin, the mass ratio of binder to soft ferrite powder is 1-1.5:100.

The mass ratio of the dispersant to the soft magnetic ferrite powder is 1-1.5:100. The dispersant may be a dispersant commonly used in the art, preferably, the dispersant is polyethylene glycol octylphenyl ether. For example, polyethylene glycol octyl phenyl ether dispersant type X-100.

In this embodiment, the composition of the ferrite slurry used to prepare the dielectric film green body layer is the same as that of the soft ferrite slurry used to prepare the first ferrite green body layer. For example, the ferrite slurry used for preparing the dielectric film green body layer may also be the LSF-11 type high-power ferrite slurry produced by Qingdao Haopu Company.

Wherein, the thickness of the dielectric film base layer is 30-50 microns.

Step S140 : forming a second ferrite green layer with a second electrode groove on the dielectric film green layer, and forming a second electrode in the second electrode groove, and the second electrode is electrically connected to the electrical connector.

Wherein, the method of forming the second ferrite green body layer with the second electrode groove on the dielectric film green body layer is screen printing. The slurry used to form the second ferrite green body layer is plastic ferrite slurry. For example, the plastic ferrite slurry of H-T type produced by Yinhui Electronic Materials Co., Ltd.

Wherein, the thickness of the second ferrite green body layer is 40-60 microns.

Wherein, the step of forming the second electrode in the second electrode groove is specifically: filling silver paste in the second electrode groove, and forming the second electrode after drying. For example, the silver paste can be the silver paste of SP19L type produced by Dongrong Company.

Step S150: providing a second ferrite substrate body, laminating the second ferrite substrate body on the second ferrite body layer, and the second ferrite substrate body covering the second ferrite body layer and the second electrode to obtain a semi-finished product.

Wherein, the preparation step of the second ferrite substrate body is: tape-casting the soft magnetic ferrite slurry and then drying to form the second ferrite substrate body. Wherein, the soft ferrite slurry used to prepare the second ferrite substrate blank is the same as the soft ferrite slurry used to prepare the first ferrite substrate blank.

Specifically, the thickness of the second ferrite substrate blank is 100-300 microns.

Wherein, Fig. 2 is a semi-finished product 200 with an inductor unit prepared through the above steps, the first ferrite substrate blank 210 is sequentially stacked with a first ferrite blank layer 220, a dielectric film blank layer 230 , the second ferrite green body layer 240 and the second ferrite substrate green body 250 . Wherein, the first electrode groove 222 is formed on the first ferrite green body layer 220, and the first electrode groove 222 is filled with the first electrode 260, and the second electrode groove 242 is formed on the second ferrite green body layer 240. , the second electrode groove 242 is filled with the second electrode 270 . An electrical connector 280 electrically connected to the first electrode 260 is formed on the first electrode 260 . The electrical connector 280 penetrates the dielectric film body layer 230 and is electrically connected to the second electrode 270 .

Further, before the step of forming the second ferrite green body layer with the second electrode groove on the dielectric film green body layer, it also includes repeatedly preparing the first ferrite green body layer, the first electrode, the electrical connection parts and dielectric film green body layers, so that a plurality of successively stacked inductor units are formed on the first ferrite substrate green body, and among two adjacent inductor units, the first ferrite green body of one inductor unit Layers are formed on the dielectric film base layer of another inductor unit, the electrical connector of one inductor unit is electrically connected to the first electrode of the other inductor unit, and the second ferrite base layer is stacked on top of the first ferrite layer. On the dielectric film blank layer of the inductor unit farthest from the substrate blank.

Step S160: Sintering the semi-finished product to obtain a chip inductor.

Wherein, the sintering step is sintering at 880° C. for 4 to 6 hours. Specifically, the sintering system is as follows: from room temperature to 230°C for 2 hours, then to 280°C for 2 hours, to 880°C for 6 hours, and to keep at 880°C for 4 to 6 hours, then to cool naturally.

The preparation method of the above-mentioned chip inductor is simple to operate and easy to industrialized production, and the preparation method of the above-mentioned chip inductor is filled in the electrode groove by filling the electrode, so that the dielectric film green body layer and the first ferrite green body layer, The connection of the second ferrite body layer is flat, avoiding the formation of air bubbles, and the way the electrodes are filled into the electrode slots can effectively increase the thickness of the electrodes, reduce the DC resistance of the electrodes, and increase the rated current of the chip inductor and reliability.

As shown in FIG. 3 , a chip inductor 300 according to an embodiment can be prepared by the above-mentioned manufacturing method of a chip inductor. The chip inductor 300 includes a first ferrite substrate 310, a first ferrite layer 320, a first electrode 330, a dielectric film layer 340, a second ferrite layer 350, a second electrode 360, and an electrical connector 370. and a second ferrite substrate 380 . Wherein, the first ferrite layer 320 , the first electrode 330 , the dielectric film layer 340 and the electrical connector 370 together form an inductor unit.

Wherein, the first ferrite layer 320 , the dielectric film layer 340 , the second ferrite layer 350 and the second ferrite substrate 380 are sequentially stacked on the first ferrite substrate 310 .

A first electrode groove 322 is opened on the first ferrite layer 320 , and the first electrode 330 is accommodated in the first electrode groove 322 .

A second electrode groove 352 is opened on the second ferrite layer 350 , and the second electrode 360 is received in the groove of the second electrode 352 .

The electrical connector 370 is disposed through the dielectric film layer 340 , and the electrical connector 370 is electrically connected to the first electrode 330 and the second electrode 360 .

The material of the dielectric film layer 340 is ferrite.

Further, there are multiple inductance units, and the plurality of inductance units are stacked on the first ferrite substrate 310 in sequence. Among two adjacent inductance units, the first ferrite layer 320 of one inductance unit is stacked on the other inductor. On the dielectric film layer 340 of the unit, and the electrical connector 370 of one inductance unit is electrically connected to the first electrode 330 of the other inductance unit, and the second ferrite layer 350 is stacked on the farthest from the first ferrite substrate 310 on the dielectric film layer 340 of the inductor unit.

The first electrode 330 and the second electrode 360 of the above-mentioned chip inductor 300 are accommodated in the first electrode groove 322 and the second electrode groove 352 respectively, so that the dielectric film layer 340 and the first ferrite layer 320, the second ferrite layer The junction of the layer 350 is flat, avoiding the formation of air bubbles, and the first electrode 330 and the second electrode 360 are accommodated in the first electrode groove 322 and the second electrode groove 352 respectively, which can effectively increase the thickness of the electrode and reduce the thickness of the electrode. The DC resistance improves the rated current and reliability of the chip inductor 300 .

The above-mentioned chip inductors can be widely used in electronic products. Among them, electronic products are notebook computers, smart phones, power converters, etc.

The following is the specific embodiment part:

Example 1

The preparation steps of the chip inductor of this embodiment are as follows:

(1) Preparation of the first ferrite substrate blank and the second ferrite substrate blank: dry the soft ferrite powder at 130°C for 9 hours, then dry the dried soft ferrite powder, acetic acid n-propyl ester, isobutanol, plasticizer, binder and dispersant are mixed to prepare soft ferrite slurry, wherein the mass ratio of n-propyl acetate to soft ferrite powder is 80:100, iso The mass ratio of butanol to soft ferrite powder is 18:100, the plasticizer is dioctyl phthalate whose model is DOP, and the mass ratio of plasticizer to soft ferrite powder is 2:100 , the binder is polymethyl methacrylate resin model B44, the mass ratio of binder to soft ferrite powder is 20:100, and the dispersant is polyethylene glycol octyl resin model X-100 The mass ratio of phenyl ether, dispersant and soft ferrite powder is 1:100. The soft magnetic ferrite slurry was tape-casted and dried at 75°C for 3.5 minutes to form a first ferrite substrate blank and a second ferrite substrate blank respectively. The thickness of the first ferrite substrate blank is 100 microns, and the thickness of the second ferrite substrate blank is 100 microns.

(2) Preparation of the first ferrite green body layer: screen-print plastic ferrite paste on the first ferrite substrate green body, and dry at 60°C for 3.5 minutes to form a layer with a thickness of 50 microns and the first The first ferrite green body layer of the electrode tank.

(3) Fill silver paste in the first electrode tank, and dry at 70° C. for 3.5 minutes to form the first electrode in the first electrode tank.

(4) Screen-print silver paste on part of the first electrodes, and dry at 70° C. for 3.5 minutes to obtain electrical connectors.

(5) Dry the soft ferrite powder at 130°C for 9 hours, then mix the dried soft ferrite powder, n-propyl acetate, isobutanol, plasticizer, binder and dispersant to prepare Become ferrite slurry, wherein, the mass ratio of n-propyl acetate and soft ferrite powder is 80:100, the mass ratio of isobutanol and soft ferrite powder is 18:100, plasticizer is The model is dioctyl phthalate of DOP, the mass ratio of plasticizer and soft magnetic ferrite powder is 2:100, and binder is the polymethyl methacrylate resin of model B44, binder and The mass ratio of the soft ferrite powder is 20:100, the dispersant is polyethylene glycol octyl phenyl ether of model X-100, and the mass ratio of the dispersant to the soft ferrite powder is 1:100. Next, coating the ferrite slurry on the first ferrite green body layer, and making the ferrite slurry cover the first ferrite green body layer and the first electrode, and exposing the electrical connector, after 75 Dry at ℃ for 3.5 minutes to form a dielectric film green body layer. The electrical connector is pierced through the dielectric film green body layer. The first ferrite green body layer, the first electrode, the electrical connector and the dielectric film green body layer together form an inductor unit . The thickness of the dielectric film green body layer is 40 microns.

(6) Screen-print the plastic ferrite paste on the dielectric film base layer, and dry it at 60° C. for 3.5 minutes to form a second ferrite base layer with a thickness of 50 μm and a second electrode groove.

(7) Fill silver paste in the second electrode tank, and dry at 70° C. for 3.5 minutes to form the second electrode, and the second electrode is electrically connected to the electrical connector.

(8) A second ferrite substrate blank is stacked on the second ferrite blank layer, and the second ferrite substrate blank covers the second ferrite blank layer and the second electrode to obtain a semi-finished product.

(9) Heat the semi-finished product from room temperature to 230°C for 2 hours, then heat up to 280°C for 2 hours, continue to heat up for 6 hours to 880°C, and keep it at 880°C for 5 hours, then cool it naturally, and then apply silver, burn silver, End processing, sorting and braiding processes are used to make chip inductors.

A HP4338B milliohm meter is used to test the DC resistance of the chip inductor of this embodiment; the rated current of the chip inductor of this embodiment is tested according to GJB1864A-2011. Wherein, the DC resistance and rated current of the chip inductor in this embodiment are shown in Table 1.

Example 2

The preparation steps of the chip inductor of this embodiment are as follows:

(1) Preparation of the first ferrite substrate blank and the second ferrite substrate blank: dry the soft ferrite powder at 150°C for 6 hours, then dry the dried soft ferrite powder, acetic acid n-propyl ester, isobutanol, plasticizer, binder and dispersant are mixed to prepare soft ferrite slurry, wherein the mass ratio of n-propyl acetate to soft ferrite powder is 75:100, iso The mass ratio of butanol to soft ferrite powder is 20:100, the plasticizer is dioctyl phthalate whose model is DOP, and the mass ratio of plasticizer to soft ferrite powder is 2.5:100 , the binder is polymethyl methacrylate resin model B44, the mass ratio of binder to soft ferrite powder is 25:100, and the dispersant is polyethylene glycol octyl resin model X-100 The mass ratio of phenyl ether, dispersant and soft ferrite powder is 1.5:100. The soft magnetic ferrite slurry was tape-casted and dried at 75°C for 3.5 minutes to form a first ferrite substrate blank and a second ferrite substrate blank respectively. The thickness of the first ferrite substrate blank is 200 microns, and the thickness of the second ferrite substrate blank is 200 microns.

(2) Preparation of the first ferrite green body layer: screen-print plastic ferrite paste on the first ferrite substrate green body, and dry at 60°C for 3.5 minutes to form a layer with a thickness of 40 microns and the first The first ferrite green body layer of the electrode tank.

(3) Fill silver paste in the first electrode tank, and dry at 70° C. for 3.5 minutes to form the first electrode in the first electrode tank.

(4) Screen-print silver paste on part of the first electrodes, and dry at 70° C. for 3.5 minutes to obtain electrical connectors.

(5) Dry the soft ferrite powder at 150°C for 6 hours, then mix the dried soft ferrite powder, n-propyl acetate, isobutanol, plasticizer, binder and dispersant to prepare Become ferrite slurry, wherein, the mass ratio of n-propyl acetate and soft ferrite powder is 75:100, the mass ratio of isobutanol and soft ferrite powder is 20:100, plasticizer is The model is DOP dioctyl phthalate, the mass ratio of plasticizer to soft magnetic ferrite powder is 2.5:100, the binder model is B44 polymethyl methacrylate resin, the binder and soft ferrite powder The mass ratio of the magnetic ferrite powder is 25:100, the dispersant is polyethylene glycol octyl phenyl ether of model X-100, and the mass ratio of the dispersant to the soft magnetic ferrite powder is 1.5:100. Next, coating the ferrite slurry on the first ferrite green body layer, and making the ferrite slurry cover the first ferrite green body layer and the first electrode, and exposing the electrical connector, after 75 Dry at ℃ for 3.5 minutes to form a dielectric film green body layer. The electrical connector is pierced through the dielectric film green body layer. The first ferrite green body layer, the first electrode, the electrical connector and the dielectric film green body layer together form an inductor unit . The thickness of the dielectric film green body layer is 30 microns.

(6) Screen-print plastic ferrite paste on the dielectric film green body layer, and dry at 60°C for 3.5 minutes to form a second ferrite green body layer with a thickness of 40 microns and a second electrode groove.

(7) Fill silver paste in the second electrode tank, and dry at 70° C. for 3.5 minutes to form the second electrode, and the second electrode is electrically connected to the electrical connector.

(8) A second ferrite substrate blank is stacked on the second ferrite blank layer, and the second ferrite substrate blank covers the second ferrite blank layer and the second electrode to obtain a semi-finished product.

(9) Heat the semi-finished product from room temperature to 230°C for 2 hours, then raise the temperature to 280°C for 2 hours, continue to heat up for 6 hours to 880°C, and keep it at 880°C for 6 hours, then cool it naturally, and then apply silver, burn silver, End processing, sorting and braiding processes are used to make chip inductors.

Using the same test method as in Example 1, the DC resistance and rated current of the chip inductor in this example are obtained as shown in Table 1.

Example 3

The preparation steps of the chip inductor of this embodiment are as follows:

(1) Preparation of the first ferrite substrate blank and the second ferrite substrate blank: dry the soft ferrite powder at 100°C for 12 hours, then dry the dried soft ferrite powder, acetic acid N-propyl ester, isobutanol, plasticizer, binder and dispersant are mixed to prepare soft ferrite slurry, wherein the mass ratio of n-propyl acetate to soft ferrite powder is 85:100, iso The mass ratio of butanol to the soft ferrite powder is 15:100, the plasticizer is dioctyl phthalate whose model is DOP, and the mass ratio of the plasticizer to the soft ferrite powder is 1.5:100 , the binder is a mixture of polymethyl methacrylate resins of type B44 and A21, the mass ratio of binder to soft ferrite powder is 1:100, and the dispersant is polyethylene oxide of type X-100 Glycol octyl phenyl ether, the mass ratio of dispersant to soft ferrite powder is 1:100. The soft magnetic ferrite slurry was tape-casted and then dried at 75° C. for 3.5 minutes to form a first ferrite substrate blank and a second ferrite substrate blank respectively. The thickness of the first ferrite substrate blank is 300 microns, and the thickness of the second ferrite substrate blank is 300 microns.

(2) Preparation of the first ferrite green body layer: screen-print the plastic ferrite paste on the first ferrite substrate green body, and dry at 60°C for 3.5 minutes to form a layer with a thickness of 60 microns and the first The first ferrite green body layer of the electrode tank.

(3) Fill silver paste in the first electrode tank, and dry at 70° C. for 3.5 minutes to form the first electrode in the first electrode tank.

(4) Screen-print silver paste on part of the first electrodes, and dry at 70° C. for 3.5 minutes to obtain electrical connectors.

(5) Dry the soft ferrite powder at 100°C for 12 hours, then mix the dried soft ferrite powder, n-propyl acetate, isobutanol, plasticizer, binder and dispersant to prepare Become ferrite slurry, wherein, the mass ratio of n-propyl acetate and soft ferrite powder is 85:100, the mass ratio of isobutanol and soft ferrite powder is 15:100, plasticizer is The model is DOP dioctyl phthalate, the mass ratio of plasticizer to soft magnetic ferrite powder is 1.5:100, and the binder is a mixture of polymethyl methacrylate resins whose models are B44 and A21. The mass ratio of the binder to the soft ferrite powder is 1:100, the dispersant is polyethylene glycol octyl phenyl ether whose model is X-100, and the mass ratio of the dispersant to the soft ferrite powder is 1:100. Next, coating the ferrite slurry on the first ferrite green body layer, and making the ferrite slurry cover the first ferrite green body layer and the first electrode, and exposing the electrical connector, after 75 Dry at ℃ for 3.5 minutes to form a dielectric film green body layer. The electrical connector is pierced through the dielectric film green body layer. The first ferrite green body layer, the first electrode, the electrical connector and the dielectric film green body layer together form an inductor unit . The thickness of the dielectric film green body layer is 50 microns.

(6) Screen-print plastic ferrite paste on the dielectric film green body layer, and dry at 60°C for 3.5 minutes to form a second ferrite green body layer with a thickness of 60 microns and a second electrode groove.

(7) Fill silver paste in the second electrode tank, and dry at 70° C. for 3.5 minutes to form the second electrode, and the second electrode is electrically connected to the electrical connector.

(8) A second ferrite substrate blank is stacked on the second ferrite blank layer, and the second ferrite substrate blank covers the second ferrite blank layer and the second electrode to obtain a semi-finished product.

(9) Heat the semi-finished product from room temperature to 230°C for 2 hours, then raise the temperature to 280°C for 2 hours, continue to heat up to 880°C for 6 hours, and keep it at 880°C for 4 hours, then cool it naturally, and then apply silver, burn silver, End processing, sorting and braiding processes are used to make chip inductors.

Using the same test method as in Example 1, the DC resistance and rated current of the chip inductor in this example are obtained as shown in Table 1.

Example 4

The preparation steps of the chip inductor of this embodiment are as follows:

(1) Preparation of the first ferrite substrate blank and the second ferrite substrate blank: dry the soft ferrite powder at 130°C for 9 hours, then dry the dried soft ferrite powder, acetic acid n-propyl ester, isobutanol, plasticizer, binder and dispersant are mixed to prepare soft ferrite slurry, wherein the mass ratio of n-propyl acetate to soft ferrite powder is 80:100, iso The mass ratio of butanol to the soft ferrite powder is 15:100, the plasticizer is dioctyl phthalate whose model is DOP, and the mass ratio of the plasticizer to the soft ferrite powder is 2:100 , the binder is a mixture of polymethyl methacrylate resins of type B44 and A21, the mass ratio of binder to soft ferrite powder is 1.5:100, and the dispersant is polyethylene oxide of type X-100 Glycol octyl phenyl ether, the mass ratio of dispersant to soft ferrite powder is 1.2:100. The soft magnetic ferrite slurry was tape-casted and then dried at 75° C. for 3.5 minutes to form a first ferrite substrate blank and a second ferrite substrate blank respectively. The thickness of the first ferrite substrate blank is 100 microns, and the thickness of the second ferrite substrate blank is 100 microns.

(2) Preparation of the first ferrite green body layer: screen-print plastic ferrite paste on the first ferrite substrate green body, and dry at 60°C for 3.5 minutes to form a layer with a thickness of 50 microns and the first The first ferrite green body layer of the electrode tank.

(3) Fill silver paste in the first electrode tank, and dry at 70° C. for 3.5 minutes to form the first electrode in the first electrode tank.

(4) Screen-print silver paste on part of the first electrodes, and dry at 70° C. for 3.5 minutes to obtain electrical connectors.

(5) Dry the soft ferrite powder at 130°C for 9 hours, then mix the dried soft ferrite powder, n-propyl acetate, isobutanol, plasticizer, binder and dispersant to prepare Become ferrite slurry, wherein, the mass ratio of n-propyl acetate and soft ferrite powder is 80:100, the mass ratio of isobutanol and soft ferrite powder is 15:100, plasticizer is The model is DOP dioctyl phthalate, the mass ratio of plasticizer to soft magnetic ferrite powder is 2:100, and the binder is a mixture of polymethyl methacrylate resins whose models are B44 and A21. The mass ratio of the binder to the soft ferrite powder is 1.5:100, the dispersant is polyethylene glycol octyl phenyl ether whose model is X-100, and the mass ratio of the dispersant to the soft ferrite powder is 1.2:100. Next, coating the ferrite slurry on the first ferrite green body layer, and making the ferrite slurry cover the first ferrite green body layer and the first electrode, and exposing the electrical connector, after 75 Dry at ℃ for 3.5 minutes to form a dielectric film green body layer. The electrical connector is pierced through the dielectric film green body layer. The first ferrite green body layer, the first electrode, the electrical connector and the dielectric film green body layer together form an inductor unit . The thickness of the dielectric film green body layer is 40 microns.

(6) Screen-print the plastic ferrite slurry on the dielectric film green body layer, dry at 60°C for 3.5 minutes to form a first ferrite green body layer with a thickness of 50 microns and a second electrode groove, and repeat In steps (3)-(5), the second inductor unit is formed on the dielectric film base layer of the first inductor unit.

(7) Screen-print plastic ferrite paste on the dielectric film base layer of the second inductance unit, and dry it at 60°C for 3.5 minutes to form a second ferrite with a thickness of 40-60 microns and a second electrode groove. Oxygen body layer.

(8) Fill the second electrode tank with silver paste, and dry at 70° C. for 3.5 minutes to form the second electrode, and the second electrode is electrically connected to the electrical connector.

(9) Laminating the second ferrite substrate green body on the second ferrite green body layer, and the second ferrite substrate green body covers the second ferrite green body layer and the second electrode to obtain a semi-finished product.

(10) Heat the semi-finished product from room temperature to 230°C for 2 hours, then raise the temperature to 280°C for 2 hours, continue to heat up to 880°C for 6 hours, and keep it at 880°C for 5 hours, cool it naturally, and then apply silver, burn silver, End processing, sorting and braiding processes are used to make chip inductors.

Using the same test method as in Example 1, the DC resistance and rated current of the chip inductor in this example are obtained as shown in Table 1.

Comparative example 1

The preparation steps of the chip inductor of Comparative Example 1 are as follows:

The first ferrite substrate with a thickness of 100 microns and the second ferrite substrate with a thickness of 100 microns are prepared by tape casting with ordinary ferrite slurry (such as the SB material magnetic permeability 80 provided by Changping), and the silver paste is used in screen-print the first electrode on the first ferrite substrate, and screen-print electrical connectors on part of the first electrode; tape-cast to prepare a dielectric film; screen-print the second electrode on the second ferrite substrate, and partially Screen printing electrical connectors on the second electrode, stacking the first ferrite substrate with the first electrode, the dielectric film and the second ferrite substrate with the second electrode to obtain a semi-finished product, the semi-finished product from room temperature Raise the temperature for 2 hours to 230°C, then raise the temperature for 2 hours to 280°C, continue to heat up for 6 hours to 880°C, and keep it at 880°C for 5 hours, then cool naturally, and then go through silver coating, silver burning, end treatment, sorting and braiding (both existing mature technology) and other processes are made into chip inductors.

Using the same test method as in Example 1, the DC resistance and rated current of the chip inductor in Comparative Example 1 are obtained as shown in Table 1.

Table 1 shows the DC resistance and rated current of the chip inductors of Examples 1-4 and Comparative Example 1.

Table 1

It can be seen from Table 1 that the DC resistance of the chip inductors in Examples 1 to 4 is at most 29mΩ, and the rated current is at least 200mA, respectively, while the DC resistance of the chip inductor in Comparative Example 1 is as high as 200mΩ, and the rated current is only 200mA. 50mA. Apparently, the chip inductors in Examples 1-4 have lower DC resistance and higher rated current, which improves the reliability of the chip inductors.

The various technical features of the above-mentioned embodiments can be combined arbitrarily. To make the description concise, all possible combinations of the various technical features in the above-mentioned embodiments are not described. However, as long as there is no contradiction in the combination of these technical features, should be considered as within the scope of this specification.

The above-mentioned embodiments only express several implementation modes of the present invention, and the descriptions thereof are relatively specific and detailed, but should not be construed as limiting the patent scope of the invention. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent for the present invention should be based on the appended claims.

Claims (10)

1. a kind of preparation method of chip inductor, it is characterised in that comprise the following steps：

First ferrite substrate base substrate is provided, first with first electrode groove is formed on the first ferrite substrate base substrate Ferrite green body layer, and form first electrode in the first electrode groove；

Electrical connector is formed on the first electrode；

Deielectric-coating green body layer, and the deielectric-coating green body layer are formed on the first ferrite green body layer using ferrite slurry The first ferrite green body layer and the first electrode are covered, the electrical connector is arranged in the deielectric-coating green body layer, its In, the first ferrite green body layer, the first electrode, the electrical connector and the deielectric-coating green body layer collectively constitute electricity Feel unit, the thickness of deielectric-coating green body layer is 30~50 microns；

The second ferrite green body layer with second electrode groove is formed in the deielectric-coating green body layer, and in the second electrode Second electrode is formed in groove, and the second electrode electrically connects with the electrical connector；

Second ferrite substrate base substrate is provided, the second ferrite substrate base is laminated on the second ferrite green body layer Body, and the second ferrite substrate base substrate covers the second ferrite green body layer and the second electrode, obtains semi-finished product； And

The semi-finished product are sintered, obtain chip inductor.

2. the preparation method of chip inductor according to claim 1, it is characterised in that also including first ferrite The preparation process of substrate base substrate and the second ferrite substrate base substrate：It will be dried after soft magnetic ferrite slurry flow casting molding, point The first ferrite substrate base substrate and the second ferrite substrate base substrate are not formed；

Wherein, the soft magnetic ferrite slurry includes soft magnetic ferrite powder, n-propyl acetate, isobutanol, plasticizer, binding agent And dispersant, the mass ratio of the n-propyl acetate and the soft magnetic ferrite powder is 75~85:100, the isobutanol with The mass ratio of the soft magnetic ferrite powder is 15~20:100.

3. the preparation method of chip inductor according to claim 1, it is characterised in that existed using the ferrite slurry The step of forming the deielectric-coating green body layer on the first ferrite green body layer be specially：In the first ferrite green body layer The upper coating ferrite slurry, and the ferrite slurry is covered the first ferrite green body layer and first electricity Pole, and expose the electrical connector, through drying, form the deielectric-coating green body layer；

Wherein, the ferrite slurry includes soft magnetic ferrite powder, n-propyl acetate, isobutanol, plasticizer, binding agent and divided The mass ratio of powder, the n-propyl acetate and the soft magnetic ferrite powder is 75~85:100, the isobutanol with it is described The mass ratio of soft magnetic ferrite powder is 15~20:100.

4. the preparation method of chip inductor according to claim 1, it is characterised in that the shape in the first electrode groove It is specially into the step of first electrode：Silver paste is filled in the first electrode groove, forms first electricity after drying Pole；

The step of forming the second electrode in the second electrode groove be specially：In the second electrode groove described in filling Silver paste, the second electrode is formed after drying.

5. the preparation method of chip inductor according to claim 1, it is characterised in that formed on the first electrode The step of electrical connector is specially：The silk-screen printing silver paste in the first electrode of part, through drying, obtain described be electrically connected Fitting.

6. the preparation method of chip inductor according to claim 1, it is characterised in that in first ferrite substrate The method that the first ferrite green body layer with the first electrode groove is formed on base substrate is silk-screen printing；In the medium The method that the second ferrite green body layer with the second electrode groove is formed in film green body layer is silk-screen printing.

7. the preparation method of chip inductor according to claim 1, it is characterised in that in the deielectric-coating green body layer Before the step of forming the second ferrite green body layer with the second electrode groove, in addition to it is repeated several times described in preparation The step of first ferrite green body layer, the first electrode, the electrical connector and deielectric-coating green body layer, so that described Multiple inductance units stacked gradually are formed on one ferrite substrate base substrate, and in the two neighboring inductance unit, one First ferrite green body layer of the individual inductance unit is formed in the deielectric-coating green body layer of another inductance unit, one The electrical connector of the inductance unit electrically connects with the first electrode of inductance unit another described, second ferrite green body It is laminated on layer by layer in the deielectric-coating green body layer of the inductance unit farthest from the first ferrite substrate base substrate.

8. the chip inductor that a kind of preparation method of chip inductor as claimed in claim 1 is prepared, its feature exist In, including the first ferrite substrate, the first ferrite layer, first electrode, media coating, the second ferrite layer, second electrode, electricity Connector and the second ferrite substrate, wherein, first ferrite layer, the media coating, second ferrite layer and Second ferrite substrate is stacked gradually on first ferrite substrate；First is offered on first ferrite layer Slot electrode, the first electrode are contained in the first electrode groove；Second electrode groove is offered on second ferrite layer, The second electrode is contained in the second electrode groove；The electrical connector is arranged in the media coating, and described is electrically connected Fitting electrically connects the first electrode and the second electrode；The material of the media coating is ferrite, the first iron oxygen Body layer, the first electrode, the media coating and the electrical connector collectively constitute inductance unit.

9. chip inductor according to claim 8, it is characterised in that the inductance unit is multiple, and multiple described Inductance unit is stacked gradually on first ferrite substrate, in the two neighboring inductance unit, an inductance list First ferrite layer of member is laminated on the media coating of another inductance unit, and inductance unit is electrically connected Fitting is electrically connected with the first electrode of inductance unit another described, and second ferrite layer is laminated in from the first iron oxygen On the media coating of the farthest inductance unit of structure base board.

10. application of the chip inductor as claimed in claim 8 or 9 in electronic product.