Semiconductor Module

Abstract

To provide a semiconductor module capable of achieving both heat dissipation and insulation.SOLUTION: A semiconductor module 100 includes a substrate 1 having a main surface 1a and a main surface 1b opposite to the main surface 1a, a semiconductor device 3 mounted on the main surface 1a, and a heat sink 7 attached to the main surface 1b via an insulating sheet 6 having thermal conductivity, and the substrate 1 has a through hole 1c penetrating from the main surface 1a to the main surface 1b, and the semiconductor device 3 includes a plurality of electrodes 4c exposed from the surface facing the main surface 1a and a projection 4b formed between the plurality of electrodes 4c and inserted through the through hole 1c. The insulating sheet 6 is formed to be longer in the thickness direction of the substrate 1 than the tip of the protrusion 4b projecting from the through hole 1c.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a semiconductor module. [Background technology]

[0002] Surface-mount semiconductor modules are generally used without a heat sink, in which case heat generated by the semiconductor chip inside the package is dissipated from the surface of the package through the resin that makes up the package into the air, or dissipated to the board through electrodes that connect the inside of the package to the outside (see, for example, Patent Document 1).

[0003] Patent Document 1 discloses a configuration in which a resin protrusion is provided on the molded resin to increase the creepage distance between adjacent lead frames (corresponding to electrodes) in order to suppress creepage currents that flow along the surface of the molded resin of a semiconductor device, and the resin protrusion fits into a through hole in a wiring board. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2014-207275 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the technology described in Patent Document 1, resin protrusions are provided in the molded resin, thereby ensuring an insulation distance between adjacent lead frames, making it possible to narrow the spacing between adjacent lead frames, i.e., to increase the size of the lead frames.

[0006] This allows a larger current to flow through the lead frame, which results in a problem that the temperature of the semiconductor module rises during operation, deteriorating the solder used in the semiconductor module and reducing the durability of the semiconductor module.

[0007] In order to improve the heat dissipation performance of a semiconductor module, it is possible to attach a heat sink to the wiring board, but the technology described in Patent Document 1 has a problem in that the insulation distance between the lead frame and the heat sink is shortened because the resin protrusion fits into the through hole of the wiring board. Thus, with the technology described in Patent Document 1, it is difficult to achieve both heat dissipation and insulation properties in a semiconductor module.

[0008] In view of the above, an object of the present disclosure is to provide a semiconductor module that is capable of achieving both heat dissipation and electrical insulation properties. [Means for solving the problem]

[0009] A semiconductor module according to the present disclosure includes a substrate having a first main surface and a second main surface opposite to the first main surface, a semiconductor device mounted on the first main surface, and a heat sink attached to the second main surface via a thermally conductive insulating member, the substrate having a first through hole penetrating from the first main surface to the second main surface. ,before The semiconductor device has a plurality of electrodes exposed from a surface opposite to the first main surface, and a protrusion formed between the plurality of electrodes and inserted into the first through hole. ,before The insulating member has a length in a thickness direction of the substrate that is longer than a tip end of the protrusion that protrudes from the first through hole. Short Formed A groove is formed on a surface of the heat sink facing the insulating member, and the tip of the protrusion is received through the insulating member. It is something. Effect of the Invention

[0010] According to the present disclosure, since the insulating member is disposed between the substrate on which the semiconductor device is mounted and the heat sink, an insulating distance can be ensured between the plurality of electrodes and the heat sink. Furthermore, heat generated in the plurality of electrodes is transferred not only from the substrate but also from the tips of the protrusions to the heat sink via the insulating member, and is dissipated to the outside by the heat sink. This allows the semiconductor module to achieve both heat dissipation and insulation. [Brief description of the drawings]

[0011] [Figure 1] 1 is a cross-sectional view of a semiconductor module according to a first embodiment. [Diagram 2] FIG. 11 is a cross-sectional view of a semiconductor module according to a second embodiment. [Diagram 3] FIG. 11 is a cross-sectional view of a semiconductor module according to a third embodiment. [Figure 4] FIG. 11 is a cross-sectional view of a semiconductor module according to a fourth embodiment. [Diagram 5] FIG. 13 is a cross-sectional view of a semiconductor module according to a fifth embodiment. [Figure 6] FIG. 13 is a cross-sectional view of a semiconductor module according to a sixth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] <Embodiment 1> The first embodiment will be described below with reference to the drawings. Fig. 1 is a cross-sectional view of a semiconductor module 100 according to the first embodiment.

[0013] In FIG. 1, the X direction, the Y direction, and the Z direction are mutually orthogonal. The X direction, the Y direction, and the Z direction shown in the following figures are also mutually orthogonal. In the following, the direction including the X direction and the -X direction opposite to the X direction is also referred to as the "X-axis direction". In the following, the direction including the Y direction and the -Y direction opposite to the Y direction is also referred to as the "Y-axis direction". In the following, the direction including the Z direction and the -Z direction opposite to the Z direction is also referred to as the "Z-axis direction".

[0014] As shown in FIG. 1, a semiconductor module 100 includes a substrate 1, a semiconductor device 3, an insulating sheet 6 (corresponding to an insulating member), and a heat sink 7 having a plurality of fin portions 7a.

[0015] The substrate 1 has a main surface 1a (corresponding to a first main surface), a main surface 1b (corresponding to a second main surface) opposite to the main surface 1a, and a through hole 1c (corresponding to a first through hole). The through hole 1c penetrates from the main surface 1a to the main surface 1b and extends in the Y-axis direction. The main surface 1a of the substrate 1 is provided with a metal pattern 2a.

[0016] The semiconductor device 3 is mounted on the main surface 1a of the substrate 1. The semiconductor device 3 includes a main body 4a, a protrusion 4b, and a plurality of electrodes 4c. The main body 4a is formed of resin in a rectangular shape when viewed from the Z-axis direction. The protrusion 4b is formed between the plurality of electrodes 4c in the main body 4a using resin, and protrudes toward the substrate 1 (Z-direction) and extends in the Y-axis direction. The protrusion 4b is formed slightly smaller than the length of the through hole 1c in the X-axis direction and the Y-axis direction so that it can be inserted into the through hole 1c of the substrate 1. Since the protrusion 4b is longer than the length in the thickness direction (Z-axis direction) of the substrate 1, the tip of the protrusion 4b protrudes from the main surface 1b of the substrate 1 when the protrusion 4b is inserted into the through hole 1c of the substrate 1.

[0017] With the protrusions 4b inserted into the through holes 1c of the substrate 1, the electrodes 4c and the metal pattern 2a are bonded to each other with a bonding material 5, thereby mounting the semiconductor device 3 on the substrate 1. The bonding material 5 is solder or a conductive resin paste.

[0018] The number of protrusions 4b may be one or more. When there are multiple protrusions 4b, they are provided side by side at intervals in the X-axis direction.

[0019] The insulating sheet 6 is made of a thermally conductive sponge and is disposed on the main surface 1b of the substrate 1 in order to ensure an insulating distance between the plurality of electrodes 4c and the heat sink 7. The heat sink 7 is fixed to the main surface 1b of the substrate 1 with screws via the insulating sheet 6. The heat sink 7 may be fastened together with the substrate 1 and the semiconductor device 3 via the insulating sheet 6.

[0020] The insulating sheet 6 is formed to be longer in the thickness direction (Z-axis direction) of the substrate 1 than the tips of the protrusions 4b protruding from the through holes 1c. The insulating sheet 6 is also flexible enough to allow the tips of the protrusions 4b to bite into the insulating sheet 6 when they come into contact with the insulating sheet 6. As a result, when the insulating sheet 6 is fixed to the substrate 1, the tips of the protrusions 4b bite into the insulating sheet 6, but the tips of the protrusions 4b do not press against the heat sink 7 via the insulating sheet 6.

[0021] By the tip portions of the projections 4b biting into the insulating sheet 6, heat generated in the multiple electrodes 4c is transferred not only from the substrate 1 but also from the tip portions of the projections 4b via the insulating sheet 6 to the heat sink 7, and is dissipated to the outside by the heat sink 7. Here, the magnitude relationship of the thermal conductivity of the members constituting the semiconductor module 100 is as follows: heat sink 7>insulating sheet 6>projections 4b>substrate 1. Therefore, in the semiconductor module 100, heat is transferred to the heat sink 7 more effectively than when the tip portions of the projections 4b do not bite into the insulating sheet 6.

[0022] As described above, the semiconductor module 100 of embodiment 1 comprises a substrate 1 having a main surface 1a and a main surface 1b opposite to main surface 1a, a semiconductor device 3 mounted on main surface 1a, and a heat sink 7 attached to main surface 1b via a thermally conductive insulating sheet 6, wherein the substrate 1 has a through hole 1c penetrating from main surface 1a to main surface 1b, the semiconductor device 3 has a plurality of electrodes 4c exposed from a surface opposite to main surface 1a, and a protrusion 4b formed between the plurality of electrodes 4c and inserted into the through hole 1c, and the insulating sheet 6 is formed to be longer in the thickness direction (Z-axis direction) of the substrate 1 than the tip of the protrusion 4b protruding from the through hole 1c.

[0023] Therefore, since the insulating sheet 6 is disposed between the substrate 1 on which the semiconductor device 3 is mounted and the heat sink 7, an insulating distance can be ensured between the plurality of electrodes 4c and the heat sink 7. Furthermore, heat generated at the plurality of electrodes 4c is transferred not only from the substrate 1 but also from the tips of the protrusions 4b to the heat sink 7 via the insulating sheet 6, and is dissipated to the outside by the heat sink 7. This makes it possible to achieve both heat dissipation and insulation properties in the semiconductor module 100. As a result, it is possible to improve the durability of the semiconductor module 100.

[0024] <Embodiment 2> Next, a semiconductor module 100A according to embodiment 2 will be described. Fig. 2 is a cross-sectional view of the semiconductor module 100A according to embodiment 2. Note that in embodiment 2, the same components as those described in embodiment 1 are denoted by the same reference numerals and description thereof will be omitted.

[0025] As shown in FIG. 2, in the second embodiment, a semiconductor module 100A includes, instead of an insulating sheet 6, an adhesive 16 that has thermal conductivity and insulating properties.

[0026] The adhesive 16 is applied to the main surface 1b of the substrate 1 to ensure an insulation distance between the multiple electrodes 4c and the heat sink 7. The substrate 1 and the heat sink 7 are joined by the adhesive 16. The adhesive 16 is applied so that the length of the adhesive 16 in the thickness direction (Z-axis direction) of the substrate 1 is longer than the tip of the projection 4b protruding from the through hole 1c, so that the tip of the projection 4b is not exposed from the adhesive 16. Here, the adhesive 16 corresponds to an insulating member.

[0027] As described above, the semiconductor module 100A according to the second embodiment includes the adhesive 16 having thermal conductivity and insulating properties instead of the insulating sheet 6, and therefore provides the same effects as those of the first embodiment.

[0028] <Embodiment 3> Next, a semiconductor module 100B according to embodiment 3 will be described. Fig. 3 is a cross-sectional view of the semiconductor module 100B according to embodiment 3. Note that in embodiment 3, the same components as those described in embodiments 1 and 2 are denoted by the same reference numerals and descriptions thereof will be omitted.

[0029] As in the case of embodiment 1, if the length of the insulating sheet 6 in the thickness direction (Z-axis direction) of the substrate 1 becomes long, the thermal conduction performance from the insulating sheet 6 to the heat sink 7 decreases, so it is preferable that the length of the insulating sheet 6 in the thickness direction (Z-axis direction) of the substrate 1 is short.

[0030] Therefore, in embodiment 3, as shown in Figure 3, the insulating sheet 6 is formed so that its length in the thickness direction (Z-axis direction) of the substrate 1 is shorter than the tip of the protrusion 4b, and a groove 7b is formed on the surface of the heat sink 7 facing the insulating sheet 6 to accommodate the tip of the protrusion 4b via the insulating sheet 6.

[0031] In the third embodiment, the length of the insulating sheet 6 in the thickness direction (Z-axis direction) of the substrate 1 is approximately 1 / 3 of that in the first embodiment. The lengths of the groove 7b in the thickness direction (Z-axis direction) of the substrate 1, the X-axis direction, and the Y-axis direction are each greater than the lengths of the tip of the protrusion 4b in the thickness direction (Z-axis direction), the X-axis direction, and the Y-axis direction, respectively, so that the tip of the protrusion 4b can be accommodated via the insulating sheet 6.

[0032] As described above, in the semiconductor module 100B of embodiment 3, the insulating sheet 6 is formed so that its length in the thickness direction (Z-axis direction) of the substrate 1 is shorter than that of the tip of the protrusion 4b, and a groove 7b is formed on the surface of the heat sink 7 facing the insulating sheet 6 to accommodate the tip of the protrusion 4b via the insulating sheet 6.

[0033] Therefore, it is possible to achieve both heat dissipation and electrical insulation in the semiconductor module 100B. Furthermore, since the thermal conductivity from the insulating sheet 6 to the heat sink 7 can be improved compared to the first embodiment, it is possible to improve the heat dissipation performance of the semiconductor module 100B compared to the first embodiment.

[0034] Furthermore, when the heat sink 7 is formed by extrusion, the grooves 7b can be formed at the same time, so that the manufacturing cost of the semiconductor module 100B does not increase compared to the first embodiment.

[0035] <Fourth embodiment> Next, a semiconductor module 100C according to embodiment 4 will be described. Fig. 4 is a cross-sectional view of the semiconductor module 100C according to embodiment 4. Note that in embodiment 4, the same components as those described in embodiments 1 to 3 are denoted by the same reference numerals and description thereof will be omitted.

[0036] In the first embodiment, the heat sink 7 is provided to improve the heat dissipation performance of the semiconductor module 100, but in cases where a heat dissipation performance lower than that of the heat sink 7 is acceptable, a ceramic heat sink 17 having a shorter length in the thickness direction (Z-axis direction) of the substrate 1 than that of the heat sink 7 is provided instead of the heat sink 7, as shown in Fig. 4. The heat sink 17 is attached in the same manner as in the case of the heat sink 7. The heat sink 17 can also be adopted in the semiconductor modules 100A and 100B of the second and third embodiments.

[0037] As described above, the semiconductor module 100C according to the fourth embodiment includes, instead of the heat sink , the heat dissipation plate 17 that is shorter in length in the thickness direction (Z-axis direction) of the substrate 1 than the heat sink .

[0038] Since the heat dissipation plate 17 is lighter in weight than the heat sink 7, it is possible to realize a semiconductor module 100C that is more resistant to vibration than the first embodiment.

[0039] <Embodiment 5> Next, a semiconductor module 100D according to embodiment 5 will be described. Fig. 5 is a cross-sectional view of the semiconductor module 100D according to embodiment 5. Note that in embodiment 5, the same components as those described in embodiments 1 to 4 are denoted by the same reference numerals and description thereof will be omitted.

[0040] As shown in Fig. 5, in the fifth embodiment, a through hole 1d (corresponding to a second through hole) is formed in the substrate 1, penetrating from the main surface 1a to the main surface 1b in addition to the through hole 1c. Metal patterns 2a and 2b are provided on the main surface 1a and the main surface 1b, respectively, to cover the through hole 1d. A conductive film (not shown) is provided on the inner wall of the through hole 1d to make the metal patterns 2a and 2b conductive. This allows a current to flow between the main surface 1a and the main surface 1b, which are both sides of the substrate 1.

[0041] The through hole 1d may be one or more. The through hole 1d may be adopted in the semiconductor modules 100A, 100B, and 100C of the second to fourth embodiments.

[0042] As described above, in the semiconductor module 100D of embodiment 5, in addition to the through hole 1c, a through hole 1d penetrating from the main surface 1a to the main surface 1b is formed in the substrate 1, and metal patterns 2a, 2b covering the through hole 1d are provided on the main surface 1a and the main surface 1b, respectively.

[0043] Therefore, heat generated in the multiple electrodes 4c is transferred from the metal pattern 2a through the through holes 1d to the metal pattern 2b, improving the heat dissipation performance compared to when the through holes 1d are not provided. In addition, since a current can flow through the main surfaces 1a and 1b, which are both sides of the substrate 1, it is also possible to suppress heat generation in the substrate 1.

[0044] <Sixth embodiment> Next, a semiconductor module 100E according to embodiment 6 will be described. Fig. 6 is a cross-sectional view of the semiconductor module 100E according to embodiment 6. Note that in embodiment 6, the same components as those described in embodiments 1 to 5 are denoted by the same reference numerals and description thereof will be omitted.

[0045] 6, in the sixth embodiment, the through-holes 1d of the substrate 1 are filled with grease 11 having heat dissipation properties. Alternatively, the through-holes 1d may be filled with a thermally conductive gel instead of the grease 11. The structure in which the through-holes 1d are filled with the grease 11 having heat dissipation properties or the gel having heat conductivity may also be employed in the semiconductor modules 100A, 100B, and 100C of the second to fourth embodiments.

[0046] As described above, in the semiconductor module 100E of embodiment 6, the through holes 1d are filled with grease 11 having heat dissipation properties or gel having thermal conductivity, thereby improving the heat dissipation performance compared to embodiment 5.

[0047] It should be noted that the embodiments can be freely combined, and each embodiment can be modified or omitted as appropriate. [Explanation of symbols]

[0048] 1 substrate, 1a, 1b main surface, 1c through hole, 1d through hole, 2a, 2b metal pattern, 3 semiconductor device, 4b protrusion, 4c electrode, 6 insulating sheet, 7 heat sink, 7b groove, 16 adhesive, 17 heat sink, 100, 100A, 100B, 100C, 100D, 100E semiconductor module.

Claims

1. a substrate having a first major surface and a second major surface opposite the first major surface; a semiconductor device mounted on the first main surface; a heat sink attached to the second main surface via an insulating member having thermal conductivity; the substrate has a first through hole penetrating from the first main surface to the second main surface, the semiconductor device has a plurality of electrodes exposed from a surface opposite to the first main surface, and a protrusion formed between the plurality of electrodes and inserted into the first through hole; the insulating member is formed to have a length in a thickness direction of the substrate shorter than a tip end of the protrusion protruding from the first through hole, a groove for receiving the tip of the protrusion with the insulating member interposed therebetween, the groove being formed on a surface of the heat sink facing the insulating member;

2. 2. The semiconductor module according to claim 1, further comprising, in place of said heat sink, a heat sink having a length shorter in the thickness direction of said substrate than said heat sink.

3. The semiconductor module according to claim 1 , wherein the thermal conductivity of the members constituting the semiconductor module satisfies the following magnitude relationship: Heat sink > insulating material > protrusion > substrate

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