JP2013045939A - Semiconductor module and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor module capable of improving a heat dissipation property with a simple structure.SOLUTION: A semiconductor module 10 comprises: a circuit board 30 that has patterned wiring paths 31; a thin plate 40 that has a lead-out portion 41 for heat dissipation and is provided on the circuit board 30; and an IC 20 that has a plurality of electrodes 21 on a surface 23 thereof and is provided on a portion other than the lead-out portion 41 on the thin plate 40 so that the surface 23 faces upward. The module has a structure in which the thin plate 40 having the lead-out portion 41 for heat dissipation is disposed between the circuit board 30 and the semiconductor chip 20, to allow heat generated from the semiconductor chip 20 to be released from the lead-out portion 41 to the outside, thereby improving a heat dissipation property with a simple structure.

Description

  The present invention relates to a semiconductor module having a heat spreader structure of a semiconductor chip mounted with face-up and a method for manufacturing the same. Hereinafter, an IC (Integrated Circuit) as a semiconductor chip will be mainly described.

  In recent years, application of optical interconnection to packet switches and cross-connects has been studied as optical communication capacity increases. In particular, for backplane applications, it is desired to develop a transmission / reception module for optical interconnection that is small and inexpensive in addition to a transmission capacity exceeding 10 [Gbps].

  Currently, in optical interconnection, a method of bundling a plurality of optical fibers and performing parallel transmission is the mainstream. A general optical interconnection transceiver module contains a plurality of transceiver elements and an IC for controlling them.

  Here, in the transmission / reception module, in order to control a plurality of transmission / reception elements, an IC having the same number of control circuits as the transmission / reception elements is required. For example, in the CXP (C = hex character for 12; XP = eXtended capability Pluggable) standard which is an MSA (Multi Source Agreement) of an optical module, a total of 24 channels of 12 channels on the transmission side and 12 channels on the reception side are included in one package (PKG). Need to fit. In this case, a control circuit for 24 channels is required, and the amount of heat generated by the IC having this control circuit becomes very large.

  Usually, a connection electrode is formed on the surface of an IC, and the IC is mounted on some wiring board. The mounting methods can be roughly divided into two types: face-down mounting in which the IC surface faces the wiring board and face-up mounting in which the IC back surface faces the wiring board.

  In face-down mounting, effective heat dissipation can be realized by connecting the IC to the wiring board by solder bumps or the like and installing a heat spreader on the back surface of the IC. However, in face-down mounting, connection reliability becomes a problem. This is because, since ICs are always required to be miniaturized, the connection electrodes of ICs in recent years and the distance between them are as small as several tens [μm].

  On the other hand, in face-up mounting, since the IC is connected to the wiring board by wire bonding, there is no problem in connection reliability. However, in face-up mounting, since heat exhausted from the IC is directly transmitted to the wiring board, it is necessary to install a heat dissipation structure on the wiring board.

  For example, in face-up mounting disclosed in Patent Documents 1 to 4, a part of the wiring board is hollowed out, and the IC is housed in the opening along with the heat sink.

Japanese Patent Laid-Open No. 2004-296565 (FIG. 1 etc.) JP 2010-021515 A (FIG. 1 etc.) JP 2011-124251 A (FIG. 1 etc.) Re-specialized WO2002084733 (Fig. 1 etc.)

  Various techniques have been conventionally employed for heat radiation from the substrate when face-up mounting is performed. For example, there are a heat dissipation substrate with improved heat conduction and a structure different from that of the wiring substrate, and a wiring substrate with a material having high thermal conductivity (such as aluminum nitride). However, each technique has a problem in that the structure and the manufacturing method are complicated, and expensive materials are required. Moreover, in the related arts of Patent Documents 1 to 4, there is a problem that the structure and the manufacturing method are complicated because a part of the wiring board is hollowed out and the IC is accommodated in the opening together with the heat sink.

  Therefore, an object of the present invention is to provide a semiconductor module that can improve heat dissipation with a simple structure.

The semiconductor module according to the present invention is
A substrate with a patterned wiring path;
A thin plate provided on the substrate, having a drawer for heat dissipation,
A semiconductor chip having a plurality of electrodes on the surface and provided with the surface up in a portion other than the lead portion on the thin plate;
It is provided with.

A method for manufacturing a semiconductor module according to the present invention includes:
On the substrate with the patterned wiring path, provide a thin plate with a heat radiating lead,
On this thin plate, a semiconductor chip having a plurality of electrodes on the surface is provided with the surface facing up,
It is characterized by that.

  According to the present invention, since the thin plate having the heat radiating lead portion is sandwiched between the substrate and the semiconductor chip, the heat generated from the semiconductor chip can be released to the outside from the lead portion. Therefore, heat dissipation can be improved with a simple structure.

It is a top view which shows Embodiment 1 of the semiconductor module which concerns on this invention. It is the II-II line longitudinal cross-sectional view in FIG. It is a top view which shows Embodiment 2 of the semiconductor module which concerns on this invention. It is a top view which shows Embodiment 3 of the semiconductor module which concerns on this invention. It is the VV line longitudinal cross-sectional view in FIG.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention (hereinafter referred to as “embodiments”) will be described with reference to the accompanying drawings. In the present specification and drawings, the same reference numerals are used for substantially the same components. The shapes depicted in the drawings are drawn so as to be easily understood by those skilled in the art, and thus do not necessarily match the actual dimensions and ratios.

[Embodiment 1]
FIG. 1 is a plan view showing a semiconductor module according to a first embodiment of the present invention. 2 is a longitudinal sectional view taken along line II-II in FIG. Hereinafter, a description will be given based on FIG. 1 and FIG.

  The semiconductor module 10 according to the first embodiment has a substrate 30 having a patterned wiring path 31, a heat-dissipating lead 41, a thin plate 40 provided on the substrate 30, and a surface (one surface) 23. The IC 20 is provided with a plurality of electrodes 21 and provided on the thin plate 40 other than the lead portion 41 with the surface 23 facing upward.

  In the manufacturing method of the semiconductor module 10 according to the first embodiment, a process of providing a thin plate 40 having a heat radiation leading portion 41 on a substrate 30 having a patterned wiring path 31, and a plurality of surfaces 23 on the thin plate 40 are provided. And a step of providing the semiconductor chip 20 having the electrode 21 with the surface 23 facing up.

  In other words, the semiconductor module 10 includes an IC 20 having a plurality of electrodes 21 on the surface 23, a substrate 30 having a patterned wiring path 31, and a heat conductive thin plate 40 having a heat radiating lead 41. Yes.

  The thin plate 40 is sandwiched between the IC 20 and the substrate 30 so that the thin plate 40 and the IC 20 are thermally connected. At least one of the plurality of electrodes 21 is electrically connected to the wiring path 31, at least one of the plurality of electrodes 21 is electrically connected to the thin plate 40, and the thin plate 40 and the substrate 30 are electrically connected. Yes.

  The electrode 21, the wiring path 31, and the thin plate 40 are connected by wire bonding, respectively. In other words, the electrode 21 is connected to the wiring path 31 and the thin plate 40 by the wire 22. The IC 20 has a quadrangular outer shape and has electrodes 21 on all four sides. The lead portion 41 is a heat dissipation path that releases heat generated from the IC 20 to the outside.

  This will be described in more detail below.

  The first embodiment is a semiconductor module 10 in which a rectangular IC 20 having electrodes 21 on four sides of a surface 23 is face-up mounted, and is characterized by a heat dissipation structure. The semiconductor module 10 is manufactured as follows.

  First, the substrate 30 and the thin plate 40 are prepared. The substrate 30 is made of alumina (aluminum oxide), and a wiring path 31 and a ground (GND) pattern 32 are patterned by gold plating. The thin plate 40 is made of copper tungsten having a thickness of 0.2 mm, and gold plating is applied to both surfaces thereof. Subsequently, the thin plate 40 is bonded onto the ground pattern 32 of the substrate 30 using solder. Subsequently, the IC 20 is mounted face up on the thin plate 40 using a silver paste. Thereafter, the electrode 21 on the surface 23 of the IC 20 and the wiring path 31 on the substrate 30 are connected using wire bonding.

  In FIG. 1, among the electrodes 21, the ground (GND) terminal 21 b is represented by a rectangle, and the other terminals 21 a are represented by a circle. Here, as shown in FIG. 1, a part of the thin plate 40 (the lead portion 41) is drawn out of the footprint of the IC 20 from the vicinity of the ground terminal 21b as a heat dissipation path. In the lead portion 41, the electrode 21 (ground terminal 21b) and the thin plate 40 are connected by wire bonding.

  As described above, the thin plate 40 is electrically joined to the ground pattern 32 of the substrate 30. Therefore, the ground terminal 21 b of the IC 20 is electrically joined to the ground pattern 32 of the substrate 30 through the thin plate 40. Further, the drawer portion 41 may be thermally connected to an external heat sink (not shown). In this case, the heat generated in the IC 20 can be effectively released.

  In other words, the first embodiment is a semiconductor having a structure that effectively dissipates heat by connecting a heat spread to the back surface of the IC 20 when the IC 20 that needs to perform wire bonding connection from a plurality of sides is face-up mounted. The module 10 is related. That is, in the first embodiment, particularly for an IC 20 having electrodes 21 on all sides with a small size and high density, the heat radiation of the IC 20 mounted face-up while using an inexpensive substrate (such as alumina) 30 with a simple single plate structure. We propose a structure that ensures safety.

  Specifically, a thin plate 40 made of a metal or metal-plated material having good thermal conductivity and conductivity is laid between the substrate 30 and the IC 20. And the drawer | drawing-out part 41 which is a part of thin plate 40 is used as a heat radiator as it is, or the drawer | drawing-out part 41 is thermally connected to an external heat radiator. At this time, the lead portion 41 interferes with the wire 22. For the interfering electrode 21, the wire 22 is connected from the electrode 21 to the lead portion 41 and is electrically connected to the substrate 30 through the conductive thin plate 40. In particular, in a small and high-density IC 20, a plurality of electrodes 21 (that is, ground terminals 21b) may be gathered at one place or several places in order to stabilize the potential, and thus the thin plate 40 is connected to the outside at such places. Assumes that.

  According to the present invention, since the thin plate 40 having the heat radiating lead portion 41 is sandwiched between the substrate 30 and the IC 20, the heat generated from the IC 20 is released from the lead portion 41 to the outside. Therefore, heat dissipation can be improved with a simple structure.

[Embodiment 2]
FIG. 3 is a plan view showing a second embodiment of the semiconductor module according to the present invention. Hereinafter, a description will be given with reference to FIG.

  The semiconductor module 50 according to the second embodiment is characterized in that the thin plate 60 has a plurality of heat-dissipating lead portions 61 and 62. This will be described in more detail below.

  The IC 70 used here is a rectangular semiconductor chip having electrodes 21 on four sides of the surface 23 and ground terminals 21b on two sides. The second embodiment relates to a heat dissipation structure in the semiconductor module 50 in which the IC 70 is mounted face up.

  Although the mounting procedure is the same as that of the first embodiment, the second embodiment is characterized in that the lead-out portions 61 and 62 as heat dissipation paths are taken out from two places as shown in FIG. According to the second embodiment, the heat resistance can be kept low by dissipating heat from two locations, and at the same time, the thermal gradient of the thin plate 60 can be reduced, so that the IC 70 can be uniformly cooled.

  Other configurations, operations, and effects of the second embodiment are the same as those of the first embodiment.

[Embodiment 3]
FIG. 4 is a plan view showing a third embodiment of the semiconductor module according to the present invention. 5 is a vertical cross-sectional view taken along line VV in FIG. Hereinafter, a description will be given based on FIGS. 4 and 5.

  The semiconductor module 80 of the third embodiment is characterized by a thin plate 90. The thin plate 90 is made of a foldable material or structure (for example, a thin plate made of metal). The heat radiating lead portion 91 is separated from the mounting surface 33 on which the wiring path 31 of the substrate 30 is patterned, led to a surface spatially different from the mounting surface 33, and used as it is as a heat radiating plate, or For example, it is connected to the heat sink 100. This will be described in more detail below.

  The third embodiment relates to a three-dimensional heat dissipation structure for a semiconductor module 80 in which a square IC 20 having electrodes 21 on four sides of the surface 23 is mounted face up. The mounting procedure of the third embodiment is the same as that of the first embodiment, but a gold-plated copper foil is used as the thin plate 90 for heat dissipation. As shown in FIG. 5, the foil-like thin plate 90 is lifted in a direction perpendicular to the substrate 30 and thermally connected to an external heat sink 100 located above the substrate 30.

  In the case of this structure, the heat radiation path can be formed not only on the plane of the substrate 30 but also three-dimensionally. Therefore, according to the third embodiment, it is possible to keep the thermal resistance low by shortening the heat radiation path, and at the same time, it is possible to increase the degree of freedom in designing the positional relationship between the IC 20 and the heat sink 100. Therefore, it is possible to optimize the structure such as miniaturization of the semiconductor module 80.

  Other configurations, operations, and effects of the third embodiment are the same as the configurations, operations, and effects of the first and second embodiments.

[Other Embodiments]
In the structure of each of the above embodiments, the same material as the IC such as Si, Ge, GaAs or the like may be used for the thin plate for heat dissipation. At this time, since the material of the thin plate is not a conductor, the side surface is plated with gold in addition to the front and back surfaces. This eliminates the difference in coefficient of thermal expansion between the thin plate and the IC, so that it is possible to suppress changes in characteristics or deterioration of reliability due to the thermal expansion of the IC. Moreover, silicon carbide or aluminum nitride can be used as the material of the thin plate.

  In the structure of each of the above embodiments, when the back surface of the IC is gold-plated, solder can be used for joining the thin plate for heat dissipation and the IC. As a result, the thermal resistance can be further reduced, and at the same time, there is an advantage that connection reliability in a high temperature and high humidity environment is improved. Moreover, you may use a silver paste and heat conductive resin instead of solder.

  The electrode electrically connected to the thin plate may be a ground terminal or a power supply terminal. In this case, since the current flows through the ground terminal or the power supply terminal, the electric resistance can be lowered by flowing the current through the thin plate, and the heat generation can be suppressed accordingly.

[Summary]
The present invention is a semiconductor module characterized by having a structure that effectively dissipates heat by connecting a heat spread to the back surface of an IC when an IC that requires wire bonding connection from a plurality of sides is face-up mounted. is there. That is, the present invention secures the heat dissipation performance of a face-up mounted IC while using an inexpensive substrate (alumina, etc.) with a simple single plate structure, particularly for a small and high density IC having electrodes on all sides. It proposes the structure to do.

  Specifically, a thin plate made of a metal or a metal-plated material having good thermal conductivity and conductivity is laid between the substrate and the IC, and a part of the thin plate is thermally connected to an external radiator. At this time, a part of the thin plate interferes with the wire wiring, but for the interfering electrode, the wire is connected from the electrode to the thin plate and electrically connected to the substrate through the conductive thin plate. In particular, in a small and high-density IC, a plurality of GND electrodes may be collected in one place or several places in order to stabilize the potential, and it is assumed that a thin plate is connected to the outside at such places. The substrate is not limited to the one on which only one semiconductor chip is mounted, and for example, a plurality of semiconductor chips, passive components, and other active components may be mounted thereon. The wiring path is not limited to a rectangle, and may be a line that electrically connects components on the board, for example.

  Although the present invention has been described with reference to the above embodiments, the present invention is not limited to the above embodiments. Various changes that can be understood by those skilled in the art can be made to the configuration and details of the present invention. Further, the present invention includes a combination of some or all of the configurations of the above-described embodiments as appropriate.

  Although a part or all of the above embodiments can be described as the following supplementary notes, the present invention is not limited to the following configurations.

[Appendix 1] a substrate having a patterned wiring path;
A thin plate provided on the substrate, having a drawer for heat dissipation,
A semiconductor chip having a plurality of electrodes on the surface and provided with the surface up in a portion other than the lead portion on the thin plate;
A semiconductor module comprising:

[Appendix 2] In the semiconductor module described in Appendix 1,
The thin plate has a plurality of the heat dissipation drawers,
A semiconductor module characterized by that.

[Appendix 3] In the semiconductor module described in Appendix 1 or 2,
The thin plate is made of a foldable material or structure,
The heat-dissipating lead portion is separated from the surface of the substrate on which the wiring path is patterned, and is led in a plane spatially different from the plane.
A module characterized by that.

[Appendix 4] In the semiconductor module according to any one of Appendixes 1 to 3,
At least one of the plurality of electrodes is electrically connected to the wiring path;
At least one of the plurality of electrodes is electrically connected to the thin plate;
The thin plate and the substrate are electrically connected;
A semiconductor module characterized by that.

[Appendix 5] In the semiconductor module described in Appendix 1 or 2,
The thin plate is made of the same semiconductor material as the semiconductor chip,
A semiconductor module characterized by that.

[Appendix 6] In the semiconductor module described in Appendix 1 or 2,
The thin plate is made of silicon carbide or aluminum nitride,
A semiconductor module characterized by that.

[Appendix 7] In the semiconductor module according to any one of Appendixes 1 to 6,
The semiconductor chip and the thin plate are joined by a silver paste, a heat conductive resin or solder,
A module characterized by that.

[Appendix 8] In the semiconductor module according to any one of Appendixes 1 to 7,
The electrode and the thin plate were electrically connected by wire bonding,
A semiconductor module characterized by that.

[Appendix 9] In the semiconductor module according to any one of Appendixes 1 to 8,
The electrode electrically connected to the thin plate is a ground terminal or a power supply terminal.
A semiconductor module characterized by that.

[Appendix 10] A thin plate having a lead-out portion for heat dissipation is provided on a substrate having a patterned wiring path,
On this thin plate, a semiconductor chip having a plurality of electrodes on the surface is provided with the surface facing up,
A method for manufacturing a semiconductor module.

[Appendix 11] A semiconductor chip having a plurality of electrodes on one surface, a substrate having a patterned wiring path, and a heat conductive thin plate having a heat radiating lead,
The thin plate is sandwiched between the semiconductor chip and the substrate so that the thin plate and the semiconductor chip are thermally connected,
At least one of the plurality of electrodes is electrically connected to the wiring path;
At least one of the plurality of electrodes is electrically connected to the thin plate;
The thin plate and the substrate are electrically connected;
A semiconductor module characterized by that.

[Appendix 12] In the semiconductor module described in Appendix 11,
The thin plate is made of metal.
A semiconductor module characterized by that.

[Appendix 13] In the semiconductor module described in Appendix 11,
The semiconductor chip is an IC whose outer shape is a square and has the electrodes on all four sides thereof.
A semiconductor module characterized by that.

  The present invention can be used for a heat dissipation structure of a semiconductor chip mounted face-up. As the semiconductor chip, an IC, a power transistor, or the like can be used.

10 Semiconductor module 20 IC (semiconductor chip)
21 Electrode 21a Other terminal 21b Ground terminal 22 Wire 23 Surface 30 Substrate 31 Wiring path 32 Ground pattern 33 Mounting surface 40 Thin plate 41 Lead part 50 Semiconductor module 60 Thin plate 61, 62 Lead part 70 IC (semiconductor chip)
80 Semiconductor module 90 Thin plate 91 Drawer 100 Heat sink

Claims (10)

A substrate with a patterned wiring path;
A thin plate provided on the substrate, having a drawer for heat dissipation,
A semiconductor chip having a plurality of electrodes on the surface and provided with the surface up in a portion other than the lead portion on the thin plate;
A semiconductor module comprising: The semiconductor module according to claim 1,
The thin plate has a plurality of the heat dissipation drawers,
A semiconductor module characterized by that. The semiconductor module according to claim 1 or 2,
The thin plate is made of a foldable material or structure,
The heat-dissipating lead portion is separated from a mounting surface on which the wiring path of the substrate is patterned, and is led in a plane spatially different from the mounting surface.
A module characterized by that. In the semiconductor module according to any one of claims 1 to 3,
At least one of the plurality of electrodes is electrically connected to the wiring path;
At least one of the plurality of electrodes is electrically connected to the thin plate;
The thin plate and the substrate are electrically connected;
A semiconductor module characterized by that. The semiconductor module according to claim 1 or 2,
The thin plate is made of the same semiconductor material as the semiconductor chip,
A semiconductor module characterized by that. The semiconductor module according to claim 1 or 2,
The thin plate is made of silicon carbide or aluminum nitride,
A semiconductor module characterized by that. The semiconductor module according to any one of claims 1 to 6,
The semiconductor chip and the thin plate are joined by a silver paste, a heat conductive resin or solder,
A module characterized by that. The semiconductor module according to any one of claims 1 to 7,
The electrode and the thin plate were electrically connected by wire bonding,
A semiconductor module characterized by that. The semiconductor module according to any one of claims 1 to 8,
The electrode electrically connected to the thin plate is a ground terminal or a power supply terminal.
A semiconductor module characterized by that. On the substrate with the patterned wiring path, provide a thin plate with a heat radiating lead,
On this thin plate, a semiconductor chip having a plurality of electrodes on the surface is provided with the surface facing up,
A method for manufacturing a semiconductor module.

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