KR101086833B1 - Printed circuit board and manufacturing method thereof - Google Patents

Abstract

The present invention relates to a structure of a printed circuit board in which a device is embedded and a method of manufacturing the same, and specifically, (A) forming a first electrode pad on a substrate; (B) forming a first bump on the first electrode pad; (C) bonding the first element on the first bump by applying heat and pressure; (D) sequentially stacking an insulating layer and a metal layer on the substrate and forming a circuit pattern on the surface layer portion; As shown in FIG.

According to the present invention, it is possible to simplify the process of fixing the device by fixing the pad and the device through the bumps on the electrode pad without going through the process of using a conventional solder when fixing the device mounted inside the printed circuit board. It has an effect.

Stud bump, Au plated bump

Description

Printed circuit board and its manufacturing method {PRINTED CIRCUIT BOARD AND MANUFACTURING METHOD OF THE SAME}

The present invention relates to a printed circuit board having a structure in which a device is embedded and a manufacturing method thereof.

With the development of advanced technology, miniaturization and high density of printed circuit boards are required, and a technology related to a printed circuit board in which various components mounted on the surface of a conventional printed circuit board are embedded in the substrate is being developed. Such a buried printed circuit board can cope with small space and high density of the surface mount portion.

Figure 1 shows a specific process example of a conventional method for manufacturing a device buried printed circuit board.

Specifically, (a) a mounting pad 31 and a circuit pattern for mounting an element only on one side of the double-sided copper-clad laminate P are formed, and a solder paste 41 is applied to the mounting pad 31 to ripple. Reflow heating is performed to fix the element 10. The insulating layer 21 and the metal layer 22 are prepared to be stacked on the copper foil laminated plate P.

(b) the insulating layer 21 and the metal layer 22 are sequentially stacked by heating and pressing, and then (c) the surface of the metal layer 22 is exposed to the mounting pads 32 through exposure, development, and etching. A circuit pattern is formed. In this case, a through hole 25 and a connection via 26 may be formed together.

Thereafter, (d) the solder paste 42 is applied on the mounting pad 32 formed in the step (c), and the device 20 is fixed by reflow heating to obtain an element-embedded printed circuit board.

However, in this process, the size of the device embedded in the printed circuit board and the device mounted on the surface of the substrate should be a special device different from each other by increasing the thickness and rigidity as the insulating layers are stacked. When fixing the solder, re-melt is generated, a problem occurs that the short between the electrodes of the internal electrode element occurs.

In addition, there is a problem in that production time or cost increases because solder paste must be printed and inspected and subjected to reflow and deflux processes.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an electrode pad without fixing a device mounted on the electrode pad in a device-embedded printed circuit board without using a solder process. The process of fixing the device and the electrode pad by using the bump can simplify the process of fixing the device.

In addition, it is possible to prevent a short circuit between the electrodes of the electrode element by remelting due to the use of solder during surface mounting of the device by not using a conventional solder process to fix the device. have.

SUMMARY OF THE INVENTION A configuration of the present invention provided to solve the above problems includes (A) forming a first electrode pad on a substrate; (B) forming a first bump on the first electrode pad; (C) bonding the first element on the first bump by applying heat and pressure; (D) sequentially stacking an insulating layer and a metal layer on the substrate and forming a circuit pattern on the surface layer portion; Provides a method for manufacturing a device-embedded printed circuit board, comprising a step of eliminating the process of using a conventional solder in fixing the device and the electrode pad to simplify the process to reduce the production time and cost for product production You can do it.

In particular, the substrate of step (A) in the above-described manufacturing process is a metal layer,

The insulating layer and the metal layer may be sequentially stacked, or the metal layer, the insulating layer, and the metal layer may be sequentially stacked.

In addition, the first bump of the step (B) is any one of a solder bump, a stud bump or an Au plating bump, characterized in that using the existing solder when fixing the device embedded in the printed circuit board It is possible to simplify the process by fixing the device by forming a bump on the electrode pad without going through the process, and after the step (B), further comprising the step of coining the first bump (Coining) If necessary, to ensure the flatness.

In addition, the step (D), (D-1) forming a second electrode pad and a circuit pattern on the surface layer; (D-2) forming a second bump on the second electrode pad; (D-3) bonding a second device on the second bump by applying heat and pressure; In the mounting of the device on the surface layer portion of the printed circuit board, it may include a bump to fix the device, the step (D), (d-1) the second electrode pad and the circuit portion in the surface layer portion Forming a pattern; (d-2) printing solder paste on the second electrode pads; (d-3) placing a second device on the solder paste; (d-4) reflowing the solder paste to fix a second device on a second electrode pad; (d-5) Deflux step of removing flux; It may include a step of printing a general solder paste when the device is mounted on the surface layer of the printed circuit board to fix the device.

In particular, the second bump of (D-2) may be any one of solder bumps, stud bumps, or Au plating bumps, and after step (D-2), coining the second bumps It characterized in that it further comprises a step to ensure the flatness of the bump.

In addition, a printed circuit board in which the device is embedded, the printed circuit board comprising: a first electrode pad formed on an inner layer of the printed circuit board; A first bump formed on the first electrode pad; A first element fixed on the first bump through heat and pressure; It may provide an element-embedded printed circuit board comprising a.

In particular, the support layer below the first electrode pad may be a metal layer, or an insulating layer and a metal layer may be sequentially stacked, or a metal layer, an insulating layer, and a metal layer may be sequentially stacked, and the first bump may include solder bumps. , Stud bump or Au plating bump, so that the device can be mounted on the internal electrode pad using bump without using solder paste.

In addition, the surface layer portion of the printed circuit board, the second electrode pad is formed, the second element is fixed to the medium via the second bump formed on the second electrode pad, the device on the surface layer portion of the printed circuit board The second bump may be any one of a solder bump, a stud bump, and an Au plating bump.

In addition, the surface layer portion of the printed circuit board, a second electrode pad is formed and the device embedded type printed circuit board, characterized in that to fix the second element by reflow heating the solder paste printed on the second electrode pad. In addition to the bumps used in mounting the device on the surface layer of the printed circuit board, a general solder paste may be used.

According to the present invention, in embedding an element in a printed circuit board, bumps are formed on an electrode pad formed in the printed circuit board and the process is simplified by mounting the element on the electrode pad using heat and pressure. As a result, the manufacturing time of the printed circuit board with the device embedded therein can be reduced in production time or cost. In other words, the solder paste is printed on the electrode pad to inspect the solder, the reflow heating is performed to fix the element on the electrode pad, and the process of performing drying and inspection through the deflux process and cleaning can be simplified.

In addition, when the device mounted inside the printed circuit board is fixed on the electrode pad by using solder paste, the internal solder is remelted by heat during the surface mounting of the device and flows between the electrode pads, causing short between electrodes. It will have the effect of blocking.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, embodiments of the present invention may be modified in many different forms, and the scope of the present invention should not be construed as being limited by the embodiments described below. Embodiments of the present invention are provided to more completely explain the present invention to those skilled in the art. Therefore, the shape and the like of the elements in the drawings are exaggerated to emphasize a more clear description, and the elements denoted by the same reference numerals in the drawings means the same elements.

2 and 3a to 3h illustrate a flow chart and process diagram for a specific manufacturing process according to the present invention. However, FIG. 2 illustrates only a flowchart of steps until a device is mounted on an electrode pad during a manufacturing process of a device-embedded printed circuit board, and an insulating layer and a metal layer are stacked to form a circuit pattern.

(A) forming a first electrode pad on a substrate; (B) forming a first bump on the first electrode pad; (C) bonding the first element on the first bump by applying heat and pressure; (D) sequentially stacking an insulating layer and a metal layer on the substrate and forming a circuit pattern on the surface layer portion; A method of manufacturing a device-embedded printed circuit board, the method comprising: a printed circuit that simplifies the process by using bumps instead of solder paste when fixing a device embedded in the printed circuit board. It is at its core to provide a substrate.

Specifically, referring to the drawing, in step 3a, the first electrode pad 120 for mounting the first device 140 is formed on the substrate 110. The substrate 110 may be formed of only a metal layer, or an insulating layer and a metal layer or a metal layer, an insulating layer, and a metal layer may be sequentially stacked. In this case, not only the first electrode pad 120 but also a circuit pattern may be formed on the substrate 110 (step S1).

In FIG. 3B, a first bump 130 is formed on the first electrode pad 120 (S2). When fixing a device through reflow heating by printing a conventional solder paste, when mounting the device on the surface layer of a printed circuit board, internal solder may be remelted to cause short circuit between electrodes. While it takes a lot of time and cost such as a reflow and a deflux process, it is possible to simplify the process when the device is mounted using bumps and there is no problem of shorting between electrodes. That is, the method used for the active die flip chip bumping is applied to the buried device. In this case, the bumps 130 may use solder bumps, stud bumps, and Au plating bumps, and FIG. 3B illustrates stud bumps. The stud bump is called having a wire (stud) of a predetermined length (height) on the crimping ball pressed onto the pad of the die. Stud bumps in a typical stud bump process, as in normal bonding wire bonding, lead the wire, such as gold, through the hole in the capillary to create a ball for forming the stud bump by electrical discharge. Then, using an ultrasonic wave generated through the hole in the capillary hole, the ball is pressed to the bonding pad of the aluminum electrode on the semiconductor chip with a proper pressure, and then the capillary is lifted up to break the wire to make a stud bump having a suitable size. Will form.

In step 3c, when the height between the formed stud bumps 130 is different due to a tail, it is preferable to perform a coining process to secure flatness.

Thereafter, in step 3d, the first device 140 may be fixed on the first bump 130 by applying heat and pressure (step S3). The use of bumps rather than solder paste eliminates the reflow process and deflux process, which simplifies the process.

Next, in step 3e, the insulating layer 150 and the metal layer 210 are sequentially stacked on the substrate 110 on which the first device 140 is mounted. (S4 step) In this case, the insulating layer 150 ) And the metal layer 210 are preferably laminated by applying heating and pressure.

In FIG. 3F, the circuit pattern 240 is formed through the stacked metal layers 210 (step S5), and the second electrode pad 220 and the second bump 230 for mounting the second device 250 are formed. ) Can be formed. In this case, in order to mount the second device 250, the general solder paste may be printed on the second electrode pad 220 instead of the second bump 230. When the solder paste is printed and the second element is mounted on the surface of the printed circuit board, the solder paste may be reflowed to fix the second element on the second electrode pad and to perform a deflux process of removing flux. have. However, in the drawing, the second bumps 230 are formed on the second electrode pads 220, and the second bumps 230 may use solder bumps, stud bumps, or Au plating bumps. The stud bump is shown in the figure.

Thereafter, in step 3g, when the stud bumps in step 3f are not the same height due to the tail, a coining process may be performed.

Next, in FIG. 3H, the device buried printed circuit board may be provided by fixing the second device 250 on the second bump 230 by applying heat and pressure.

3A to 3H are cross-sectional views illustrating elements and electrode pads in cross-sections of printed circuit boards. Accordingly, a circuit pattern may be formed on the substrate 110 of FIG. 3A, and the circuit pattern may be formed on both sides of the substrate 110 as a double-sided copper-clad laminate. Connection vias may be formed. In addition, the present invention can provide a device-embedded printed circuit board and a method of manufacturing the same by applying the same process to a multilayer board as well as a single layer.

The best embodiments have been disclosed in the drawings and specification above. Although specific terms have been used herein, they are used only for the purpose of describing the present invention and are not used to limit the scope of the present invention as defined in the meaning or claims. Therefore, those skilled in the art will understand that various modifications and equivalent other embodiments are possible from this. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

1 is a manufacturing process diagram of a device-embedded printed circuit board according to the prior art.

2 is a flowchart of a method of manufacturing an element-embedded printed circuit board according to an exemplary embodiment of the present invention.

3A to 3H are manufacturing process diagrams of a device-embedded printed circuit board according to a preferred embodiment of the present invention.

<Code Description of Main Parts of Drawing>

110 substrate 120 first electrode pad

130: first bump 140: first element

150: insulating layer 210: metal layer

220: second electrode pad 230: second bump

240: circuit pattern 250: second element

Claims (14)

(A) forming a first electrode pad on the substrate; (B) forming a ball for forming a stud bump in the capillary; (C) pressing the ball onto the first electrode pad at a predetermined pressure to bond the ball; (D) lifting the capillary to break a wire to form a first bump; (E) coining the first bumps; (F) bonding a first device on the first bump by applying heat and pressure; (G) sequentially stacking an insulating layer and a metal layer on the substrate and forming a circuit pattern on the surface layer portion; Method for manufacturing a device buried printed circuit board comprising a. The method according to claim 1, The substrate of step (A), Metal layer, The insulation layer and the metal layer are stacked in this order, A method of manufacturing a device-embedded printed circuit board, wherein a metal layer, an insulating layer, and a metal layer are sequentially stacked. delete delete The method according to claim 1 or 2, Step (G), (G-1) forming a second electrode pad and a circuit pattern on the surface layer portion; (G-2) forming a second bump on the second electrode pad; (G-3) bonding a second device on the second bump by applying heat and pressure; Method for manufacturing a device buried printed circuit board comprising a. The method according to claim 1 or 2, Step (G), (G-1) forming a second electrode pad and a circuit pattern on the surface layer portion; (G-2) printing solder paste on the second electrode pads; (G-3) placing a second device on the solder paste; (G-4) reflowing the solder paste to fix a second device on a second electrode pad; (G-5) Deflux step of removing flux; Method for manufacturing a device buried printed circuit board comprising a. delete The method according to claim 6, After the step (G-2), And coining the second bumps. In a printed circuit board in which the device is embedded, A first electrode pad formed on an inner layer of the printed circuit board; A ball is formed to form a stud bump in a capillary and is pressed by pressing the ball on the first electrode pad at a predetermined pressure, and is formed by lifting the capillary to break a wire, and coining The first bump to be processed; A first element fixed on the first bump through heat and pressure; A device buried printed circuit board comprising a. The method according to claim 9, The support layer at the bottom of the first electrode pad, Metal layer, The insulation layer and the metal layer are stacked in this order, An element-embedded printed circuit board, wherein a metal layer, an insulating layer, and a metal layer are sequentially stacked. delete The method according to claim 10, The surface layer portion of the printed circuit board, A second electrode pad is formed, And a second device fixed through the second bump formed on the second electrode pad. delete The method according to claim 10, The surface layer portion of the printed circuit board, And a second electrode pad is formed to fix the second element by reflow heating the solder paste printed on the second electrode pad.

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