Semiconductor apparatus

Abstract

The present invention provides a semiconductor cooling apparatus that has high cooling performance. A semiconductor apparatus (10) according to the present invention comprises: a semiconductor module (51) that is provided with a heating element (1) that is a semiconductor chip; and a cooling device (52) that is provided so as to face the semiconductor module (51). The semiconductor module (51) is provided with a substrate (2) on which the heating element (1) is mounted, and a module case (20) for securing the substrate (2). The cooling device (52) is provided with a cooling case (21) that accommodates a cooling fluid, and fins (11) that are provided to the cooling case (21). The module case (20) is provided with a hole (30) on a surface that faces the cooling device (52). The cooling case (21) is provided with a protrusion (31) that protrudes toward the semiconductor module (51). The protrusion (31) passes through the hole (30) and is connected to the heating element (1) with an insulating resin (5) interposed therebetween.

Description

Semiconductor device

[0001] The present invention relates to a semiconductor device, and particularly to a semiconductor device provided with a cooling device.

[0002] In recent years, in-vehicle electronic systems represented by an advanced driver assistance system (ADAS) have been evolving. A large number of sensors such as cameras, radars, and lidars are connected to in-vehicle electronic systems, and an electronic control unit (ECU), which is a semiconductor device, controls these sensors. Further, from the viewpoints of ease of control and improvement of signal quality, etc., the ECU has been changing to an architecture called an integrated ECU (or a central centralized processing ECU), in which the ECUs are collectively arranged in one place within the electronic system.

[0003] The structure of the integrated ECU is considered to have a multi-board structure in which a plurality of substrates on which heat generating bodies are mounted are electrically connected to each other. A typical heat generating body is, for example, a SoC (System on Chip) which is a semiconductor chip. Further, with an increase in power consumption and heat generation of the SoC, a water cooling method is generally becoming the mainstream for the cooling method of the SoC.

[0004] In addition to this, from the viewpoints of cost reduction, etc., a configuration (an upgradable configuration) in which a plurality of substrates on which SoCs having different performances are mounted are prepared and the substrates can be exchanged according to the desired performance is also required for the integrated ECU.

[0005] An example of a conventional semiconductor device is described in Patent Document 1. The circuit module described in Patent Document 1 includes a thermally conductive board forming a part of the housing, a circuit board having an opening, a semiconductor chip connected to a plurality of electrode pads on the upper surface of the circuit board, a heat sink joined to the upper surface of the semiconductor chip, and a thermally conductive member passing through the opening of the circuit board and contacting the lower surface of the semiconductor chip and the surface of the thermally conductive board, and enhances the cooling effect of semiconductor components on the circuit board.

[0006] Japanese Unexamined Patent Application Publication No. 2009-117612

[0007] In semiconductor devices, the substrate on which the heat-generating semiconductor chip (e.g., SoC) is mounted is sometimes enclosed in a case for vibration resistance. Upgradable configurations of semiconductor devices can be achieved by replacing modules that include both the substrate and the case.

[0008] In conventional semiconductor devices, when the substrate is covered by a case, insulating resin is required between the heat-generating element and the module case, and between the module case and the cooling device case, in order to ensure a heat dissipation path from the heat-generating element to the cooling device (e.g., a water cooling device). However, semiconductor devices with this configuration have the problem that the heat-generating element cannot obtain sufficient cooling performance because the thermal resistance of the insulating resin is high.

[0009] The objective of the present invention is to provide a semiconductor cooling device with high cooling performance.

[0010] The semiconductor device according to the present invention comprises a semiconductor module equipped with a heating element which is a semiconductor chip, and a cooling device disposed opposite the semiconductor module. The semiconductor module comprises a substrate on which the heating element is mounted, and a module case for fixing the substrate. The cooling device comprises a cooling case containing a cooling fluid and fins provided on the cooling case. The module case has holes on the surface facing the cooling device. The cooling case has protrusions that project toward the semiconductor module. The protrusions are connected to the heating element via an insulating resin through the holes.

[0011] According to the present invention, a semiconductor cooling device with high cooling performance can be provided. Problems, configurations, and effects other than those described above will be clarified by the following description of embodiments for carrying out the invention.

[0012] This is a cross-sectional view showing an example of the configuration of a conventional semiconductor device. This is a cross-sectional view showing an example of the configuration of a semiconductor device according to Embodiment 1 of the present invention. This is an exploded view showing an example of the configuration of a semiconductor device according to Embodiment 2 of the present invention. This is an exploded view showing an example of the configuration of a semiconductor device according to Embodiment 3 of the present invention. This is a cross-sectional view showing an example of the configuration of a semiconductor device according to Embodiment 4 of the present invention. This is a cross-sectional view showing an example of the configuration of a semiconductor device according to Embodiment 5 of the present invention. This is a diagram showing an example of an elastic member in an extended state in Embodiment 5. This is a diagram showing an example of an elastic member in a contracted state in Embodiment 5. This is a cross-sectional view showing an example of the configuration of a semiconductor device according to Embodiment 6 of the present invention.

[0013] The semiconductor device according to the present invention has a module case for a semiconductor module equipped with a heating element, which is provided with holes, and a cooling case for a cooling device, which is provided with protrusions, which are connected to the heating element via an insulating resin through the holes. With this configuration, the semiconductor device according to the present invention can reduce the thermal resistance of the insulating resin and improve the cooling performance of the heating element.

[0014] Furthermore, in the semiconductor device according to the present invention, the module case is detachable from the cooling case, allowing for easy replacement of the semiconductor module. Therefore, in the semiconductor device according to the present invention, it is possible to replace (upgrade) the substrate of the semiconductor module to match the desired performance on a per-semiconductor module basis.

[0015] First, an example of a conventional semiconductor device configuration will be explained using Figure 1.

[0016] Figure 1 is a cross-sectional view showing an example of the configuration of a conventional semiconductor device. The conventional semiconductor device 100 comprises a module case 20 and a cooling case 21, and a substrate 2 on which a heating element 1 is mounted is fixed to the module case 20. The cooling case 21 contains cooling water 12. An insulating resin 5a is provided between the heating element 1 and the module case 20, and an insulating resin 5b is provided between the module case 20 and the cooling case 21. The insulating resins 5a and 5b are provided to ensure a heat dissipation path for the heating element 1.

[0017] Conventional semiconductor devices 100 have a problem in that the heat-generating element 1 cannot obtain sufficient cooling performance due to the high thermal resistance of the insulating resins 5a and 5b.

[0018] Embodiments of the present invention will be described below with reference to the drawings. The embodiments are illustrative examples for explaining the present invention, and have been omitted and simplified as appropriate for clarity of explanation. The present invention can also be carried out in various other forms. Unless otherwise specified, each component may be singular or plural.

[0019] The positions, sizes, shapes, and ranges of the components shown in the drawings may not represent their actual positions, sizes, shapes, and ranges in order to facilitate understanding of the invention. Therefore, the present invention is not necessarily limited to the positions, sizes, shapes, and ranges disclosed in the drawings.

[0020] When there are multiple components with the same or similar function, they may be described using the same symbol but with different subscripts. Furthermore, when it is not necessary to distinguish between these multiple components, the subscripts may be omitted in the description.

[0021] An example of a semiconductor device according to an embodiment of the present invention is an electronic control unit (ECU). In the drawings referenced herein, the same or corresponding components are denoted by the same reference numerals, and repeated descriptions of these components may be omitted.

[0022] A semiconductor device according to Embodiment 1 of the present invention will be described with reference to Figure 2.

[0023] Figure 2 is a cross-sectional view showing an example of the configuration of the semiconductor device 10 according to this embodiment. The semiconductor device 10 according to this embodiment includes a semiconductor module 51 and a cooling device 52 arranged opposite the semiconductor module 51.

[0024] The semiconductor module 51 comprises a heating element 1, which is a semiconductor chip such as an SoC; a substrate 2 on which the heating element 1 is mounted; an insulating resin 5 placed on the heating element 1; and a module case 20 that houses and secures the substrate 2.

[0025] The substrate 2 is installed in the module case 20 via a fixing member 6a and is fixed to the module case 20 by substrate fixing bolts 3 and the fixing member 6a. The fixing member 6a is located between the substrate 2 and the module case 20 and is made of a flexible material, for example, so that it can be freely deformed to fill the gap between the substrate 2 and the module case 20. The insulating resin 5 is installed on the surface of the heating element 1 opposite to the surface in contact with the substrate 2 and has electrical insulating properties.

[0026] The module case 20 is an enclosure that covers the substrate 2. The module case 20 has a hole 30 on the surface facing the cooling device 52, at a position facing the heat-generating element 1.

[0027] The cooling device 52 comprises a cooling case 21, fins 11 provided inside the cooling case 21, and a protrusion 31.

[0028] The cooling case 21 is an enclosure that houses the cooling fluid, cooling water 12, and is installed facing the module case 20. The fins 11 are provided on the surface of the cooling case 21 that faces the semiconductor module 51.

[0029] The protrusion 31 is provided on the surface of the cooling case 21 facing the semiconductor module 51 and protrudes toward the semiconductor module 51. In this embodiment, the protrusion 31 is integrated with the cooling case 21.

[0030] The hole 30 in the module case 20 is provided on the surface of the module case 20 facing the cooling case 21. The protrusion 31 of the cooling device 52 protrudes from the cooling case 21 toward the module case 20, is inserted into the hole 30, and contacts the insulating resin 5 through the hole 30. Therefore, the heating element 1 is connected to the protrusion 31 of the cooling device 52 via the insulating resin 5.

[0031] The module case 20, cooling case 21, fins 11, and protrusions 31 are made of a high thermal conductivity material, such as metal, which allows for high cooling performance.

[0032] A fixing member 6b is installed between the module case 20 and the cooling case 21. The fixing member 6b is made of, for example, a flexible material and can be freely deformed to fill the gap between the module case 20 and the cooling case 21. The module case 20 and the cooling case 21 are fixed to each other by housing fixing bolts 4 and the fixing member 6b. In this way, the semiconductor module 51 is fixed to the cooling device 52.

[0033] In the following, the direction in which the semiconductor module 51 and the cooling device 52 are aligned (the vertical direction in Figure 2) will be referred to as the height direction. The thicknesses of the module case 20 and the cooling case 21 are their respective lengths in the height direction.

[0034] The semiconductor device 10 according to this embodiment has the above configuration, and while housing the substrate 2 in the module case 20, the length of the insulating resin portion in the heat transfer path from the heating element 1 to the fin 11 can be shortened compared to conventional designs, thereby reducing thermal resistance. For this reason, the semiconductor device 10 according to this embodiment has high cooling performance and can sufficiently cool the heating element 1.

[0035] It is preferable that the area of ​​the portion of the protrusion 31 facing the heating element 1 is large. When the area of ​​the portion of the protrusion 31 facing the heating element 1 is large, the contact area with the heating element 1 via the insulating resin 5 is increased, and the cooling performance can be improved. Furthermore, even if the semiconductor module 51 is replaced and the area of ​​the portion of the heating element 1 facing the protrusion 31 becomes larger, or if the position of the heating element 1 relative to the protrusion 31 changes, the protrusion 31 can still contact the heating element 1 via the insulating resin 5, and the cooling performance can be maintained.

[0036] Furthermore, in the semiconductor device 10 according to this embodiment, the module case 20 and the cooling case 21 are fixed to each other by housing fixing bolts 4, so the module case 20 is detachable from the cooling case 21. Therefore, the semiconductor module 51 can be easily replaced, and the substrate 2 can be replaced (upgraded) on a module-by-module basis to match the desired performance.

[0037] If the height of the heating element 1 changes due to the replacement of the semiconductor module 51, the heating element 1 can be brought into contact with the protrusion 31 by replacing the module case 20 with one whose height has been adjusted to match the height of the heating element 1, thereby maintaining the cooling performance. Alternatively, even without replacing the module case 20, the cooling performance can be maintained by replacing the fixing member 6a with one whose height has been adjusted to match the height of the heating element 1.

[0038] In this embodiment, the semiconductor device 10 can be upgraded in units of semiconductor modules 51.

[0039] A semiconductor device 10 according to Embodiment 2 of the present invention will be described with reference to Figure 3. Below, the differences between the semiconductor device 10 according to Embodiment 1 and the semiconductor device 10 according to Embodiment 1 will be mainly described.

[0040] Figure 3 is an exploded view showing an example of the configuration of the semiconductor device 10 according to this embodiment.

[0041] In the semiconductor device 10 according to this embodiment, the protrusion 31 of the cooling device 52 is a component independent of the cooling case 21 and is detachable from the cooling case 21. The protrusion 31 has a groove 32 on the surface facing the cooling case 21.

[0042] The protrusion 31 is inserted into the hole 30 and installed so as to be in contact with the cooling case 21 and the insulating resin 5. The housing fixing bolts 4 fix the module case 20 and the cooling case 21 to each other, thereby fixing the position of the protrusion 31 inside the hole 30.

[0043] In the semiconductor device 10 according to this embodiment, the protrusion 31 is detachable from the cooling case 21, so it can be replaced or its position inside the hole 30 can be changed. For example, if the semiconductor module 51 is replaced and the area of ​​the part of the heating element 1 facing the protrusion 31 becomes larger, or if the position or height of the heating element 1 changes, the cooling performance can be maintained by replacing or changing the position of the protrusion 31 in accordance with the changes in the heating element 1.

[0044] For example, when the height of the heating element 1 changes due to the replacement of the semiconductor module 51 for the upgrade of the substrate 2, even if the module case 20 or the fixing member 6a is not replaced, by replacing the convex portion 31, the convex portion 31 can be brought into contact with the heating element 1 through the insulating resin 5, and the cooling performance can be maintained.

[0045] Further, when upgrading to a substrate 2 on which components with a height higher than that of the heating element 1 are mounted near the heating element 1, and the component and the convex portion 31 come into contact with each other so that the convex portion 31 cannot contact the heating element 1 through the insulating resin 5, the convex portion 31 can be brought into contact with the heating element 1 by replacing the convex portion 31 or changing the position of the convex portion 31.

[0046] In the semiconductor device 10, friction may occur between the semiconductor module 51 and the cooling device 52 due to vibration applied from the outside, and metal friction may occur between the convex portion 31 and the cooling case 21. In this embodiment, since the convex portion 31 is provided with a groove 32 on the surface facing the cooling case 21, the metal powder generated by this metal friction can be received by the groove 32. Since the groove 32 accommodates such metal powder, it is possible to prevent malfunction caused by the metal powder contacting the substrate 2.

[0047] The semiconductor device 10 according to Embodiment 3 of the present invention will be described with reference to FIG. 4. Hereinafter, the semiconductor device 10 according to this embodiment will be mainly described with respect to the differences from the semiconductor device 10 according to Embodiment 1.

[0048] FIG. 4 is an exploded view showing an example of the configuration of the semiconductor device 10 according to this embodiment.

[0049] In the semiconductor device 10 according to this embodiment, the cooling case 21 includes a metal plate 22 on the surface facing the semiconductor module 51. The metal plate 22 is detachable from the cooling case 21 and is a component independent of the cooling case 21. The metal plate 22 includes fins 11 and a convex portion 31.

[0050] The metal plate 22 is fixed to the module case 20 and the cooling case 21 with the housing fixing bolts 4. The metal plate 22 is fastened with the housing fixing bolts 4 so that no gap can be formed between the metal plate 22 and the cooling case 21.

[0051] Since the metal plate 22 is detachable from the cooling case 21, when the semiconductor module 51 is replaced for the upgrade of the circuit board 2, the metal plate 22 can be replaced to match the semiconductor module 51. Also, by replacing the metal plate 22, the fins 11 can be replaced.

[0052] The semiconductor device 10 according to this embodiment has such a configuration that it can be upgraded in units of semiconductor modules 51, and furthermore, the fins 11 can also be replaced. For this reason, in the semiconductor device 10 according to this embodiment, even if the amount of heat generated by the heat-generating element 1 increases due to, for example, the replacement of the semiconductor module 51, the cooling performance can be improved by replacing the fins 11 with high-performance ones that have a greater heat dissipation effect, thereby coping with the increase in the amount of heat generated by the heat-generating element 1.

[0053] A semiconductor device 10 according to Embodiment 4 of the present invention will be described with reference to Figure 5. Below, the differences between the semiconductor device 10 according to Embodiment 1 and the semiconductor device 10 according to Embodiment 1 will be mainly described.

[0054] Figure 5 is a cross-sectional view showing an example of the configuration of the semiconductor device 10 according to this embodiment.

[0055] In the semiconductor device 10 according to this embodiment, the protrusion 31 has a side surface 31b and a tip surface 31a, and the side surface 31b is inclined with respect to the tip surface 31a. That is, the side surface 31b is an inclined surface. The tip surface 31a of the protrusion 31 is the surface (protruding surface) that faces the heating element 1. The side surface 31b of the protrusion 31 is the surface that intersects with the tip surface 31a.

[0056] In the semiconductor device 10 according to this embodiment, the cooling device 52 may be equipped with a plate-shaped member 40 on the protrusion 31. The plate-shaped member 40 is provided on the surface of the protrusion 31, at least on the tip surface 31a and the side surface 31b, and is located between the protrusion 31 and the resin 5. The plate-shaped member 40 can be made of a material with high thermal conductivity, such as metal, a vapor chamber, and a graphite sheet. The plate-shaped member 40 increases the thermal conductivity of the protrusion 31 in the direction along the surface of the protrusion 31, and promotes the transfer of heat from the heating element 1 in this direction.

[0057] In this embodiment, the semiconductor device 10 has a sloped side surface 31b of the protrusion 31. For example, even if a component taller than the heating element 1 is mounted near the heating element 1 on the substrate 2, contact between this component and the protrusion 31 can be prevented, and the protrusion 31 can be expanded in a direction perpendicular to the height direction (i.e., the area of ​​the portion facing the heating element 1 can be increased). Furthermore, if the protrusion 31 is equipped with a plate-like member 40, the plate-like member 40 can actively conduct heat to the lower portion of the protrusion 31. The lower portion of the protrusion 31 is the portion that is short in distance to the fin 11. Therefore, if the side surface 31b of the protrusion 31 is sloped and the protrusion 31 is equipped with a plate-like member 40, the cooling performance can be further improved.

[0058] Furthermore, since the side surface 31b of the protrusion 31 is sloped, the connection angle between the protrusion 31 and the cooling case 21 is large, and the plate-shaped member 40 can bend smoothly at this connection point, thus preventing damage to the plate-shaped member 40.

[0059] A semiconductor device 10 according to Embodiment 5 of the present invention will be described using Figures 6 and 7a and 7b. Below, the differences between the semiconductor device 10 according to Embodiment 1 and the semiconductor device 10 according to Embodiment 1 will be mainly described.

[0060] The semiconductor device 10 according to this embodiment is equipped with a case-to-case distance adjustment mechanism. The case-to-case distance adjustment mechanism is a mechanism for changing the distance between the module case 20 and the cooling case 21. For example, if the height of the heating element 1 changes due to the replacement of the semiconductor module 51, the distance between the module case 20 and the cooling case 21 can be easily adjusted using the case-to-case distance adjustment mechanism. The case-to-case distance adjustment mechanism is not limited to the configuration exemplified below and can be equipped with any configuration.

[0061] Figure 6 is a cross-sectional view showing an example of the configuration of the semiconductor device 10 according to this embodiment.

[0062] The semiconductor device 10 according to this embodiment includes an elastic member 33 installed inside the module case 20 between the substrate 2 and the protrusion 31 as a case-to-case distance adjustment mechanism. The elastic member 33 is expandable and contractible in the height direction of the heating element 1 and can be made of, for example, metal.

[0063] The elastic member 33, which is a case-to-case distance adjustment mechanism, stretches in the height direction due to its elastic force and applies force to the protrusion 31. When the force of the elastic member 33 is applied to the protrusion 31, the cooling case 21 moves away from the module case 20. As a result, the distance between the module case 20 and the cooling case 21 changes.

[0064] Figures 7A and 7B show examples of the elastic member 33. The elastic member 33 can be made of, for example, a leaf spring. Figure 7A shows the elastic member 33 in an extended state. Figure 7B shows the elastic member 33 in a compressed state.

[0065] The inter-case distance adjustment mechanism may also have the following configuration:

[0066] The inter-case distance adjustment mechanism may include housing fixing bolts 4 (Figure 6) and holes (bolt holes) provided in the cooling case 21 and the module case 20 into which the housing fixing bolts 4 are inserted. The bolt holes in the cooling case 21 penetrate through the cooling case 21, and the bolt holes in the module case 20 penetrate through the module case 20.

[0067] If the bolt holes penetrate both the cooling case 21 and the module case 20, and the housing fixing bolts 4 are sufficiently long, both ends of the housing fixing bolts 4 can protrude from the cooling case 21 and the module case 20. Nuts are provided on the portions of the housing fixing bolts 4 that protrude from the cooling case 21 or the module case 20 to fasten the cooling case 21 and the module case 20 together.

[0068] As a mechanism for adjusting the distance between cases, the distance between the module case 20 and the cooling case 21 can be changed by having the housing fixing bolt 4 protrude from only one of the cooling case 21 and the module case 20, having the housing fixing bolt 4 protrude from both the cooling case 21 and the module case 20, changing the length of the protruding portion of the housing fixing bolt 4, and changing the fastening force of the housing fixing bolt 4 to the cooling case 21 and the module case 20 by the nut.

[0069] The semiconductor device 10 according to this embodiment is equipped with a case-to-case distance adjustment mechanism that changes the distance between the module case 20 and the cooling case 21. For example, even if a component taller than the heating element 1 is mounted near the heating element 1 on the substrate 2, it is easy to change the distance between the module case 20 and the cooling case 21 to prevent contact between this component and the protrusion 31. For this reason, it is easy to replace the semiconductor module 51 in order to upgrade the substrate 2.

[0070] Even if the protrusion 31 has the shape shown in Figure 6, the protrusion 31 can be inserted into the hole 30 of the module case 20 by making the surface of the module case 20 facing the cooling case 21 openable and closable (or making a part of this surface openable and closable).

[0071] A semiconductor device 10 according to Embodiment 6 of the present invention will be described with reference to Figure 8. Below, the differences between the semiconductor device 10 according to Embodiment 1 and the semiconductor device 10 according to Embodiment 1 will be mainly described.

[0072] Figure 8 is a cross-sectional view showing an example of the configuration of the semiconductor device 10 according to this embodiment.

[0073] The semiconductor device 10 according to this embodiment includes an insulating member 34 inside the module case 20 that covers the side surface of the heating element 1. The side surface of the heating element 1 is the surface that intersects with the surface facing the protrusion 31 of the heating element 1. The insulating member 34 is an electrically insulating material and extends in the height direction from the substrate 2 to the surface of the module case 20 with the hole 30, covering the side surface of the heating element 1 without any gaps. The shape of the insulating member 34 can be arbitrarily determined. The insulating member 34 can be made of, for example, the same material as the insulating resin 5 or a clay-like heat conductive material.

[0074] The semiconductor device 10 according to this embodiment has the above configuration, provides high cooling performance, can be upgraded in units of semiconductor modules 51, and the insulating member 34 acts as an electromagnetic shield, improving reliability against electromagnetic noise.

[0075] The insulating member 34 is preferably made of a material with a higher thermal conductivity than air. If the insulating member 34 has a higher thermal conductivity than air, the cooling performance can be further improved.

[0076] 1...heating element, 2...substrate, 3...substrate fixing bolt, 4...housing fixing bolt, 5...insulating resin, 5a, 5b...insulating resin, 6a, 6b...fixing member, 10...semiconductor device, 11...fin, 12...cooling water, 20...module case, 21...cooling case, 22...metal plate, 30...hole, 31...protrusion, 31a...tip surface, 31b...side surface, 32...groove, 33...elastic member, 34...insulating member, 40...plate-shaped member, 51...semiconductor module, 52...cooling device, 100...conventional semiconductor device.

Claims

1. A semiconductor device comprising: a semiconductor module having a heating element which is a semiconductor chip; and a cooling device disposed opposite to the semiconductor module, wherein the semiconductor module comprises a substrate on which the heating element is mounted and a module case for fixing the substrate; the cooling device comprises a cooling case containing a cooling fluid and fins provided on the cooling case; the module case has a hole on the surface facing the cooling device; the cooling case has a protrusion that projects toward the semiconductor module; and the protrusion is connected to the heating element via an insulating resin through the hole.

2. The semiconductor device according to claim 1, wherein the protrusion is detachable from the cooling case.

3. The semiconductor device according to claim 2, wherein the protrusion has a groove on the surface facing the cooling case.

4. The semiconductor device according to claim 1, wherein the cooling case comprises a metal plate that is detachable from the cooling case, and the metal plate comprises the fins and the protrusions.

5. The semiconductor device according to claim 1, wherein the protrusion comprises a side surface and a tip surface facing the heating element, and the side surface is inclined with respect to the tip surface.

6. The semiconductor device according to claim 1, further comprising a case-to-case distance adjustment mechanism for changing the distance between the module case and the cooling case.

7. The semiconductor device according to claim 6, wherein the case-to-case distance adjustment mechanism is an elastic member installed inside the module case between the substrate and the protrusion.

8. The semiconductor device according to claim 6, wherein the inter-case distance adjustment mechanism comprises holes provided in the module case and the cooling case, and bolts inserted into the holes for fixing the module case and the cooling case to each other, the holes provided in the module case penetrate the module case, and the holes provided in the cooling case penetrate the cooling case.

9. The semiconductor device according to claim 1, further comprising an insulating member inside the module case that covers the side surface of the heating element.

10. The semiconductor device according to claim 1, wherein a flexible fixing member is installed between the cooling case and the module case.

11. The semiconductor device according to claim 1, wherein a flexible fixing member is installed between the substrate and the module case.

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