JP2009088169A - Element mounting substrate, semiconductor module, and method of manufacturing element mounting substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an element mounting substrate with high heat dissipation property, and to provide a semiconductor module having the same. <P>SOLUTION: In the element mounting substrate 10, an insulating layer 12 contains a filler which is formed of an insulating resin and has higher heat conductivity than that of the resin. An electrode 14 is provided in the insulating layer 12. An exposed portion 16a is exposed on the surface of the insulating layer 12 on the same side as the side where the electrode 14 is exposed. Consequently, when a semiconductor element is mounted on the element mounting substrate 10 and a terminal of the semiconductor element is connected to the electrode 14, the exposed portion 16a comes in contact with the semiconductor element with higher possibility, so the heat dissipation is more enhanced. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an element mounting substrate, a semiconductor module, and a method for manufacturing the element mounting substrate.

  In recent years, power consumption has been on the rise as circuit elements such as LSIs are further enhanced in performance and functionality. Further, as electronic devices are downsized, mounting boards are also required to be downsized and high density. For this reason, the power consumption (heat density) per volume of the circuit board is increased, and the necessity for heat radiation countermeasures is increasing.

On the other hand, flexible substrates have been frequently used due to demands for miniaturization of equipment and improvement in freedom of equipment design. The flexible substrate includes, for example, a support film made of an insulating material and a wiring layer formed of metal so as to be in contact with the support film. A flexible substrate is very thin compared to a hard printed circuit board and has a small mass at the same time, which contributes greatly to downsizing and weight reduction of equipment. Further, as a circuit board, a board having an insulating layer in which glass fibers are mixed into a resin for improving strength and functionality is also used (for example, Patent Document 1).
JP 2007-227809 A

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a technology for realizing an element mounting substrate with high heat dissipation and a semiconductor module including the same.

  In order to solve the above problems, an element mounting substrate according to an aspect of the present invention is provided with an insulating layer formed using an insulating resin and containing a filler having a higher thermal conductivity than the resin, and the insulating layer. An electrode. The filler has an exposed portion exposed from the surface on the same side as the side where the electrode of the insulating layer is exposed.

  According to this aspect, when the semiconductor element is mounted and operated, heat generated in the semiconductor element can be radiated through the filler having a higher thermal conductivity than the resin of the insulating layer.

  Another embodiment of the present invention is a semiconductor module. This semiconductor module includes a semiconductor element and an element mounting substrate. The exposed portion is in contact with the surface of the semiconductor element.

  According to this aspect, when the semiconductor element is operated, a semiconductor module capable of dissipating heat generated in the semiconductor element through the filler having higher thermal conductivity than the resin of the insulating layer can be realized with a simple configuration. it can.

  Yet another embodiment of the present invention is a method for manufacturing an element mounting substrate. The method includes the steps of preparing a substrate having an insulating layer formed of an insulating resin and including a filler having a higher thermal conductivity than the resin, forming an electrode on the insulating layer, Removing a surface on the same side as the side where the electrode is exposed, and exposing a part of the filler.

  According to this aspect, it is possible to easily manufacture an element mounting substrate with high heat dissipation.

  ADVANTAGE OF THE INVENTION According to this invention, the heat dissipation of an element mounting board | substrate and a semiconductor module provided with the same can be improved.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and repeated descriptions are omitted as appropriate. Moreover, the structure described below is an illustration and does not limit the scope of the present invention at all.

(First embodiment)
FIG. 1 is a cross-sectional view showing a schematic configuration of an element mounting substrate according to the first embodiment. The element mounting substrate 10 includes an insulating layer 12 formed of an insulating resin and an electrode 14 provided on the insulating layer 12. The insulating layer 12 includes a glass cloth 16 as a filler having a thermal conductivity higher than that of the contained resin. The glass cloth 16 is a fibrous filler oriented so that the direction of the fibers intersects the direction perpendicular to the surface of the substrate. The resin according to the present embodiment has a thermal conductivity of 0.2 W / m · K, and the glass cloth 16 has a thermal conductivity of about 1.0 W / m · K. The glass cloth 16 has an exposed portion 16a exposed from the surface on the same side as the side where the electrode 14 of the insulating layer 12 is exposed.

  Therefore, when a semiconductor element in which a predetermined circuit is formed by a known technique is mounted on the element mounting substrate 10 and operated, heat generated in the semiconductor element is dissipated through the glass cloth 16 having a higher thermal conductivity than the resin. It becomes possible to do.

  The element mounting substrate 10 has a wiring layer 18 formed on the lower surface side of the insulating layer 12 shown in FIG. The electrode 14 according to the present embodiment includes a via conductor 20 formed in a hole penetrating the insulating layer 12 and electrically connected to the wiring layer 18 at one end. That is, the other end of the via conductor 20 functions as an electrode to which the terminal of the semiconductor element is connected.

  The glass cloth 16 on the side where the wiring layer 18 of the insulating layer 12 is not formed may be configured such that the height h1 of at least a part of the exposed portion 16a is higher than the height h2 of the electrode 14. Here, the height can be regarded as the degree of unevenness in the direction perpendicular to the reference plane parallel to the surface of the insulating layer 12. As a result, when the semiconductor element is mounted on the element mounting substrate 10 and the terminal of the semiconductor element and the electrode 14 are connected, the exposed portion 16a is more likely to come into contact with the semiconductor element. Can be increased.

  Next, a method for manufacturing the element mounting substrate 10 will be described. 2 to 4 are process cross-sectional views illustrating a method for manufacturing an element mounting substrate according to the first embodiment.

  First, as shown in FIG. 2A, a substrate 22 having an insulating layer 12 formed of an insulating resin and including a glass cloth 16 having a higher thermal conductivity than that of the resin is prepared. The insulating layer 12 has a first conductor film 24 formed on one surface thereof and a second conductor film 26 formed on the other surface thereof.

  Next, as shown in FIG. 2B, a part of the insulating layer 12 is removed by irradiating a laser from the second conductor film 26 side until the first conductor film 24 is exposed, and the opening 28 is formed. Form. Here, for example, a carbon dioxide laser can be used for laser irradiation. Laser irradiation is performed in two stages: a first irradiation condition for digging to an arbitrary depth with a beam having a high energy density, and a second irradiation condition for adjusting the shape of the via sidewall with a beam having a low energy density. Thus, an opening 28 having a diameter of about 80 to 100 μm having a tapered side wall whose diameter decreases as it approaches the first conductor film 24 from the surface of the insulating layer 12 can be formed as a via.

  Next, as shown in FIG. 3A, copper is plated on the inner surface of the opening 28 to a thickness of about 20 μm using an electroless plating method and an electrolytic plating method. As a result, the via conductor 30 is formed inside the opening 28, and the first conductor film 24 and the second conductor film 26 are conducted through the via. Thereafter, as shown in FIG. 3B, the wiring layer 18 is formed by etching the second conductor film 26 into a predetermined pattern by a known method.

  Next, as shown in FIG. 4A, the first conductor film 24 is peeled off, and a part of the via conductor 30 is removed by etching. Thereby, the electrode 14 is formed on the insulating layer 12. Thereafter, as shown in FIG. 4B, the resin on the surface of the insulating layer 12 on the same side as the side where the electrode 14 is exposed is dissolved and removed, and a part of the glass cloth 16 is exposed to mount the element. The substrate 10 for manufacturing is manufactured. Thus, according to this Embodiment, the element mounting board | substrate 10 with high heat dissipation can be manufactured easily. In the present embodiment, since the electrode is formed by removing a part of the via conductor 30, an element mounting substrate in which the height of the exposed portion 16 a is higher than the height of the electrode 14 is easily manufactured. be able to.

  FIG. 5 is a process sectional view showing the method for manufacturing the semiconductor module according to the first embodiment. First, as shown in FIG. 5A, a semiconductor element 32 such as an LSI or an IC is mounted on the element mounting substrate 10. At this time, the terminal 34 of the semiconductor element 32 and the electrode 14 of the element mounting substrate 10 are connected by metal bonding by pressure bonding. The pressure at the time of pressure bonding is, for example, about 1.5 MPa. In the present embodiment, the terminal 34 and the electrode 14 are made of the same copper. However, for example, gold may be plated on the surface of the copper, and the gold may be bonded by bonding.

  Thereafter, as shown in FIG. 5B, the wiring layer 18 is covered with a solder resist layer 36. The solder resist layer 36 functions as a protective film for the wiring layer 18, and an epoxy resin or the like can be used. Then, solder bumps 38 functioning as external connection terminals are formed on the wiring layer 18 exposed from the opening of the solder resist layer 36 by using a solder printing method, and the semiconductor module 100 is completed.

  In the semiconductor module 100, as shown in FIG. 5B, the exposed portion 16a of the glass cloth 16 is in contact with the surface of the semiconductor element 32 on the terminal 34 side. Thus, the semiconductor module 100 according to the present embodiment can dissipate the heat generated in the semiconductor element 32 through the glass cloth 16 having a higher thermal conductivity than the resin of the insulating layer 12.

(Second Embodiment)
In the semiconductor module 100 according to the first embodiment, the connection between the terminal 34 and the electrode 14 is directly performed by metal bonding. However, in the semiconductor module according to the present embodiment, the bonding between the terminal 34 and the electrode 14 is performed. This is done via solder. The following description will focus on differences from the first embodiment.

  6 and 7 are process cross-sectional views of a method for manufacturing an element mounting substrate according to the second embodiment. The element mounting substrate according to the present embodiment is manufactured using the substrate 22 in which the openings 28 are formed by laser as in the process shown in FIG.

  As shown in FIG. 6A, according to the element mounting substrate manufacturing method of the present embodiment, all openings 28 are filled with copper by using an electroless plating method and an electrolytic plating method. As a result, a via conductor 42 is formed inside the opening 28, and the first conductor film 24 and the second conductor film 26 are conducted through the via. Thereafter, as shown in FIG. 6B, the second conductor film 26 is etched into a predetermined pattern by a known method to form the wiring layer 18.

  Next, as shown in FIG. 7A, the first conductor film 24 is peeled off, and a part of the via conductor 42 is removed by etching. Thereby, the electrode 14 is formed on the insulating layer 12. At this time, since the via conductor 42 is filled in the entire opening 28, it is possible to prevent the via conductor 42 from forming a through hole even if the amount of etching of the removed via conductor 42 is increased.

  Further, as the etching amount of the via conductor 42 increases, the step between the surface of the via conductor 42 that is recessed from the insulating layer 12 and the surface of the insulating layer 12 increases. Therefore, as shown in FIG. 7B, when the resin on the surface of the insulating layer 12 on the same side as the electrode 14 is exposed is dissolved and removed, the exposed portion 16a of the glass cloth 16 increases, The difference between the height h3 of the exposed portion 16a and the height h4 of the electrode 14 is increased. Thus, according to the present embodiment, it is possible to easily manufacture the element mounting substrate 40 with higher heat dissipation. In the present embodiment, since the electrode is formed by removing a part of the via conductor 42, an element mounting substrate in which the height of the exposed portion 16a is higher than the height of the electrode 14 is easily manufactured. be able to.

  FIG. 8 is a process cross-sectional view illustrating the method for manufacturing the semiconductor module according to the second embodiment. First, as shown in FIG. 8A, a semiconductor element 32 such as an LSI or an IC is mounted on an element mounting substrate 40. At this time, the terminal 34 of the semiconductor element 32 and the electrode 14 of the element mounting substrate 10 are connected via the solder 44. As described above, in the element mounting substrate 40, the difference between the height h3 of the exposed portion 16a and the height h4 of the electrode 14 is larger than in the case of the element mounting substrate 10 of the first embodiment. Therefore, it becomes possible to manufacture a semiconductor module using the thick solder 44, and the degree of freedom of the manufacturing process is increased.

  Thereafter, as shown in FIG. 8B, the wiring layer 18 is covered with a solder resist layer 36. The solder resist layer 36 functions as a protective film for the wiring layer 18, and an epoxy resin or the like can be used. Then, solder bumps 38 functioning as external connection terminals are formed on the wiring layer 18 exposed from the opening of the solder resist layer 36 by using a solder printing method, and the semiconductor module 200 is completed.

  In the semiconductor module 200, as shown in FIG. 8B, the exposed portion 16 a of the glass cloth 16 is in contact with the surface of the semiconductor element 32 on the terminal 34 side. Thus, the semiconductor module 200 according to the present embodiment can dissipate the heat generated in the semiconductor element 32 through the glass cloth 16 having a higher thermal conductivity than the resin of the insulating layer 12.

(Third embodiment)
In each of the semiconductor modules described above, the terminal of the semiconductor element is provided so as to protrude from the surface. However, in this embodiment, the case where the terminal of the semiconductor element is provided at a location recessed from the surface will be described.

  FIG. 9 is a process cross-sectional view of the element mounting substrate manufacturing method according to the third embodiment. The element mounting substrate according to the present embodiment is manufactured using the substrate 22 on which the wiring layer 18 is formed in the step shown in FIG.

  According to the method for manufacturing an element mounting substrate according to the present embodiment, as shown in FIG. 9A, a part of the first conductor film 24 is removed by etching, and the other part functions as the electrode 14. Leave as a wiring layer. As a result, the electrode 14 including the wiring layer is formed on the insulating layer 12 without requiring a step of removing a part of the via conductor 30. Thereafter, as shown in FIG. 9B, the resin on the surface of the insulating layer 12 on the same side as the side where the electrode 14 is exposed and from which the first conductor film 24 is removed is dissolved and removed. Then, a part of the glass cloth 16 is exposed to manufacture the element mounting substrate 50. Thus, according to this Embodiment, the element mounting board | substrate 50 with high heat dissipation can be manufactured easily.

  In the present embodiment, since a part of the first conductor film 24 is left and used as the electrode 14, an element mounting substrate in which the height of the exposed portion 16 a is lower than the height of the electrode 14 is easily manufactured. be able to.

  FIG. 10 is a process cross-sectional view illustrating the method of manufacturing the semiconductor module according to the third embodiment. First, as shown in FIG. 10A, a semiconductor element 52 such as an LSI or an IC is mounted on an element mounting substrate 50. At this time, the terminal 54 of the semiconductor element 52 is provided at a location recessed from the surface of the semiconductor element 52. Therefore, even if the semiconductor element 52 is mounted on the element mounting substrate 50 in which the electrode 14 protrudes from the exposed portion 16 a, the exposed portion 16 a can come into contact with the surface of the semiconductor element 52.

  That is, when the terminal 54 of the semiconductor element 52 to be mounted is provided at a location recessed from the surface, the terminal 54 of the semiconductor element 52 can be formed without removing the via conductor 30 and forming the electrode 14. Since the surface on the provided side can be in contact with the exposed portion 16a, the process can be simplified.

  Thereafter, as shown in FIG. 10B, the wiring layer 18 is covered with a solder resist layer 36. The solder resist layer 36 functions as a protective film for the wiring layer 18, and an epoxy resin or the like can be used. Then, solder bumps 38 functioning as external connection terminals are formed on the wiring layer 18 exposed from the opening of the solder resist layer 36 by using a solder printing method, and the semiconductor module 300 is completed.

  In the semiconductor module 300, as shown in FIG. 10B, the exposed portion 16 a of the glass cloth 16 is in contact with the surface of the semiconductor element 32 on the terminal 34 side. As described above, the semiconductor module 300 according to the present embodiment can dissipate heat generated in the semiconductor element 52 through the glass cloth 16 having a higher thermal conductivity than the resin of the insulating layer 12.

  The present invention has been described with reference to each of the above-described embodiments. However, this is an exemplification, and the present invention is not limited to each of the above-described embodiments, and the configuration of each embodiment is appropriately set. Combinations and substitutions are also included in the present invention. Various modifications such as design changes can be added to each embodiment based on the knowledge of those skilled in the art, and the embodiments to which such modifications are added are also included in the scope of the present invention. sell.

It is sectional drawing which shows schematic structure of the element mounting substrate which concerns on 1st Embodiment. FIG. 2A and FIG. 2B are process cross-sectional views illustrating a method for manufacturing an element mounting substrate according to the first embodiment. FIG. 3A and FIG. 3B are process cross-sectional views illustrating the method for manufacturing the element mounting substrate according to the first embodiment. FIG. 4A and FIG. 4B are process cross-sectional views illustrating the method for manufacturing the element mounting substrate according to the first embodiment. FIG. 5A and FIG. 5B are process cross-sectional views illustrating the method for manufacturing the semiconductor module according to the first embodiment. FIG. 6A and FIG. 6B are process cross-sectional views illustrating a method for manufacturing an element mounting substrate according to the second embodiment. FIG. 7A and FIG. 7B are process cross-sectional views of the method for manufacturing the element mounting substrate according to the second embodiment. FIG. 8A and FIG. 8B are process cross-sectional views illustrating a method for manufacturing a semiconductor module according to the second embodiment. FIG. 9A and FIG. 9B are process cross-sectional views of the method for manufacturing the element mounting substrate according to the third embodiment. FIG. 10A and FIG. 10B are process cross-sectional views illustrating a method for manufacturing a semiconductor module according to the third embodiment.

Explanation of symbols

  10 element mounting substrate, 12 insulating layer, 14 electrodes, 16 glass cloth, 16a exposed portion, 18 wiring layer, 20 via conductor, 22 substrate, 24 first conductor film, 26 second conductor film, 28 opening, 30 via conductor, 32 semiconductor element, 34 terminal, 36 solder resist layer, 38 solder bump, 40 element mounting substrate, 42 via conductor, 44 solder, 50 element mounting substrate, 52 semiconductor element, 54 terminal, 100 semiconductor module.

Claims (10)

An insulating layer formed of an insulating resin and including a filler having a higher thermal conductivity than the resin;
An electrode provided on the insulating layer,
The element mounting substrate, wherein the filler has an exposed portion exposed from a surface on the same side as the side where the electrode of the insulating layer is exposed. A wiring layer formed on one surface of the insulating layer;
The element mounting substrate according to claim 1, wherein the electrode includes a via conductor electrically connected to the wiring layer. A first wiring layer formed on one surface of the insulating layer so as to be electrically connected to a semiconductor element;
A second wiring layer formed on the other surface of the insulating layer;
A via conductor that penetrates through the insulating layer and electrically connects the first wiring layer and the second wiring layer,
The element mounting substrate according to claim 1, wherein the electrode includes a part of the first wiring layer.   3. The element mounting substrate according to claim 1, wherein the filler is configured such that at least a part of the exposed portion has a height higher than a height of the electrode.   The element mounting substrate according to claim 1, wherein the filler is glass fiber. A semiconductor element;
An element mounting substrate according to any one of claims 1 to 5,
The exposed module is in contact with the surface of the semiconductor element. Preparing a substrate having an insulating layer formed of an insulating resin and including a filler having a higher thermal conductivity than the resin;
Forming an electrode on the insulating layer;
Removing the surface of the insulating layer on the same side as the side where the electrode is exposed, exposing a part of the filler;
A method for manufacturing an element mounting board, comprising: The step of forming the electrode includes:
Forming a via in the insulating layer having a first conductor film formed on one surface and a second conductor film formed on the other surface;
Forming a via conductor that electrically connects the first conductor film and the second conductor film through the via;
Removing at least a portion of the first conductor film;
Have
8. The method for manufacturing a device mounting board according to claim 7, wherein the step of exposing a part of the filler removes the surface of the insulating layer from which the first conductor film is removed.   9. The method for manufacturing a device mounting board according to claim 8, further comprising a step of removing a part of the via conductor after the step of removing at least a part of the first conductor film.   The method for manufacturing an element mounting substrate according to claim 6 or 7, wherein the filler is glass fiber.

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