semiconductor devices

Abstract

The present invention provides a technique for reducing the height of protruding portions on the surface of a semiconductor module. The semiconductor device comprises a semiconductor module having a first groove; a disc spring having a recessed portion on its outer surface and a protruding portion on its inner surface; and a screw that passes through a hole in the disc spring and the first groove of the semiconductor module to screw the semiconductor module into place. The head of the screw is received in the recessed portion of the disc spring, while at least a portion of the protruding portion of the disc spring is received in the first groove of the semiconductor module.

Description

Technical Field

[0001] The present invention relates to a semiconductor device including a semiconductor module mounted on a mounted body. Background Art

[0002] Various technologies have been proposed for semiconductor devices having a semiconductor module mounted on a mounted object. For example, Patent Document 1 proposes a technology for mounting a semiconductor module on a mounted object by screwing the semiconductor module and the mounted object together via a disk spring having a hollow, substantially truncated cone shape. This technology allows the disk spring to disperse the stress generated by the screwing, thereby enabling the semiconductor module to be stably mounted on the mounted object.

[0003] Patent Document 1: Japanese Patent Application Laid-Open No. 2011-35265 Summary of the Invention

[0004] However, in the above-mentioned technology, the screw heads and disc springs protrude from the surface of the semiconductor module by their thickness. Due to the protrusion of the screw heads and disc springs from the surface of the semiconductor module, for example, it may be difficult to properly attach a control board to the surface of the semiconductor module.

[0005] Therefore, the present invention has been made in view of the above-mentioned problem, and an object of the present invention is to provide a technology capable of suppressing the height of a protruding portion on the surface of a semiconductor module.

[0006] The semiconductor device according to the present invention comprises: a semiconductor module having a first groove; a disc spring which is recessed from its own hole to the peripheral portion of the hole, thereby having a recessed portion on the outer surface and a convex portion on the inner surface; and a screw which passes through the hole of the disc spring and the first groove of the semiconductor module to screw the semiconductor module into place with a mounted body, the head of the screw being accommodated in the recessed portion of the disc spring, and at least a portion of the convex portion of the disc spring being accommodated in the first groove of the semiconductor module.

[0007] Effects of the Invention

[0008] According to the present invention, the head of the screw is received in the concave portion of the disc spring, and at least a portion of the convex portion of the disc spring is received in the first groove of the semiconductor module. This can reduce the height of the protruding portion on the surface of the semiconductor module.

[0009] The objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description and accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1This is a cross-sectional view showing the structure of the semiconductor device according to the first embodiment.

[0011] Figure 2 This is a cross-sectional view showing the structure of a semiconductor device according to Modification 1 of Embodiment 1.

[0012] Figure 3 This is a cross-sectional view showing the structure of a semiconductor device according to Modification 2 of Embodiment 1.

[0013] Figure 4 This is a cross-sectional view showing the structure of a semiconductor device according to Modification 3 of Embodiment 1.

[0014] Figure 5 This is a cross-sectional view showing the structure of a semiconductor device according to Modification 4 of Embodiment 1.

[0015] Figure 6 This is a cross-sectional view showing the structure of a semiconductor device according to Modification 4 of Embodiment 1.

[0016] Figure 7 This is a cross-sectional view showing the structure of a semiconductor device according to Modification 4 of Embodiment 1.

[0017] Figure 8 This is a cross-sectional view showing the structure of a semiconductor device according to Modification 5 of Embodiment 1.

[0018] Figure 9 It is a cross-sectional view showing the structure of a semiconductor device according to the second embodiment.

[0019] Figure 10 This is a cross-sectional view showing the structure of a semiconductor device according to a modified example of the second embodiment.

[0020] Figure 11 This is a cross-sectional view showing the structure of a semiconductor device according to a modified example of the second embodiment.

[0021] Figure 12 It is a cross-sectional view showing the structure of a semiconductor device according to a third embodiment.

[0022] Figure 13 It is a cross-sectional view showing the structure of a semiconductor device according to a fourth embodiment.

[0023] Figure 14 This is a cross-sectional view showing the structure of a semiconductor device according to Modification 1 of Embodiment 4.

[0024] Figure 15 This is a cross-sectional view showing the structure of a semiconductor device according to a second modification of the fourth embodiment.

[0025] Figure 16This is a cross-sectional view showing the structure of a semiconductor device according to a third modification of the fourth embodiment.

[0026] Figure 17 This is a cross-sectional view showing the structure of a semiconductor device according to a fourth modification of the fourth embodiment. DETAILED DESCRIPTION

[0027] <Implementation Method 1>

[0028] Figure 1 It is a cross-sectional view showing the structure of the semiconductor device according to the first embodiment of the present invention. Figure 1 The semiconductor device includes a semiconductor module 1, a disc spring 2, and screws 3. The semiconductor module 1 is mounted on a cooling portion 11, which is a mounting body, by the screws 3. The cooling portion 11 is, for example, a cooling fin.

[0029] The semiconductor module 1 has a first groove 1a on the surface opposite to the surface in contact with the cooling unit 11. The semiconductor module 1 includes semiconductor elements (not shown), such as a MOSFET (Metal Oxide Semiconductor Field Effect Transistor), an IGBT (Insulated Gate Bipolar Transistor), an SBD (Schottky Barrier Diode), and a PND (PN Junction Diode), and a resin member covering the semiconductor elements. The shape of the semiconductor module 1 is substantially the same as that of the resin member of the semiconductor module 1. The presence of the first groove 1a in the semiconductor module 1 corresponds to the presence of the first groove 1a in the resin member.

[0030] Furthermore, the semiconductor module 1 according to the first embodiment includes the electrode terminals 1 b protruding laterally and the heat conductor 1 c provided on the surface in contact with the cooling portion 11 .

[0031] The disc spring 2 has a hollow, substantially truncated cone shape, similar to a conventional disc spring, and has a hole 2a in the center. The hole 2a of the disc spring 2 extends to the periphery of the hole 2a in a direction offset from the center of the disc spring 2 to the outer periphery 2d of the disc spring 2 ( Figure 1 The disc spring 2 is recessed in the same direction as the lower direction. Figure 1 The upper surface of the Figure 1 The lower surface) has a protrusion 2c.

[0032] Screws 3 pass through holes 2a in disc springs 2 and first grooves 1a in semiconductor module 1, threading semiconductor module 1 to cooler 11. The outer peripheral portion 2d of disc spring 2 is elastically movable relative to the central portion of disc spring 2 in the height direction of the roughly truncated cone shape. This disc spring 2 disperses the stress generated by screws 3 from the screws 3 to the semiconductor module 1, compressing a wide area of ​​the semiconductor module 1. Consequently, semiconductor module 1 can be stably mounted to cooler 11.

[0033] In the semiconductor device according to the first embodiment, the head 3a of the screw 3 is received in the recessed portion 2b of the disc spring 2, and at least a portion of the protruding portion 2c of the disc spring 2 is received in the first groove 1a of the semiconductor module 1. This structure reduces the height of the protruding portions of the screw 3 head 3a and the disc spring 2 on the surface of the semiconductor module 1. Furthermore, by making the disc spring 2 concave, it is possible to prevent the disc spring 2 from rotating in reverse.

[0034] <Variation 1 of Embodiment 1>

[0035] In embodiment 1, as Figure 2 As shown, the depth of the first groove 1a of the semiconductor module 1 may be greater than or equal to the height of the protrusion 2c of the disc spring 2. With this configuration, the protrusion 2c of the disc spring 2 can be substantially entirely accommodated in the first groove 1a, thereby reducing the height of the protruding portion on the surface of the semiconductor module 1.

[0036] <Variation 2 of Embodiment 1>

[0037] In embodiment 1, as Figure 3 As shown, the semiconductor module 1 may further include a second groove 1d for accommodating the outer peripheral portion 2d of the disc spring 2. This configuration allows the entire disc spring 2 to be positioned substantially close to the semiconductor module 1, thereby reducing the height of the protruding portion on the surface of the semiconductor module 1. Furthermore, the stress on the disc spring 2 is reduced, thereby preventing the disc spring 2 from rotating in reverse.

[0038] <Variation 3 of Embodiment 1>

[0039] In the second modification of the first embodiment, Figure 4 As shown, as long as the outer peripheral portion 2d of the disc spring 2 can press the semiconductor module 1, the depth of the first groove portion 1a and the depth of the second groove portion 1d may be different. With this structure, the height of the protruding portion on the surface of the semiconductor module 1 can be suppressed, and the disc spring 2 can press a wide area of ​​the semiconductor module 1.

[0040] <Variation 4 of Embodiment 1>

[0041] In embodiment 1, as Figure 5 and Figure 6 As shown, the cross-sectional shape of the hole 2a of the disc spring 2 may also correspond to the cross-sectional shape of at least a portion of the head 3a of the screw 3. Figure 5 In the embodiment, the cross-sectional shape of the hole 2a of the disc spring 2 corresponds to the cross-sectional shape of a portion of the head 3a of the screw 3. Figure 6 In FIG. 1 , the cross-sectional shape of the hole 2 a of the disc spring 2 corresponds to the cross-sectional shape of the entire head 3 a of the screw 3 .

[0042] In addition, in the first embodiment, it is also possible to replace Figure 5 and Figure 6 The structure, such as Figure 7 As shown, the cross-sectional shape of the hole 2a of the disc spring 2 corresponds to the cross-sectional shape of the entire head 3a of the screw 3 and the root 3b of the head 3a of the screw 3. This structure can reduce the height of the protruding portion on the surface of the semiconductor module 1 and suppress the looseness of the disc spring 2 relative to the screw 3.

[0043] <Variation 5 of Embodiment 1>

[0044] In embodiment 1, as Figure 8 As shown, the cross-sectional shape of the first groove 1a of the semiconductor module 1 corresponds to the cross-sectional shape of at least a portion of the protrusion 2c of the disc spring 2. Furthermore, the cross-sectional shape of the first groove 1a of the semiconductor module 1 may also include a tapered shape. This structure reduces the height of the protruding portion on the surface of the semiconductor module 1, allowing compression over a wider area of ​​the semiconductor module 1.

[0045] <Implementation Method 2>

[0046] Figure 9 2 is a cross-sectional view showing the structure of a semiconductor device according to Embodiment 2 of the present invention. Components according to Embodiment 2 that are identical or similar to the above-described components are denoted by identical or similar reference numerals, and the description will focus on the different components.

[0047] In the second embodiment, the disc spring 2 is a normal disc spring and does not have Figure 1 The screw 3 passes through the hole 2a of the disc spring 2 and screws the semiconductor module 1 to the cooling unit 11. Figure 3 In this way, the semiconductor module 1 includes the groove portion 1 e that accommodates the outer peripheral portion 2 d of the disc spring 2 .

[0048] This structure allows the entire disc spring 2 to be brought substantially closer to the semiconductor module 1, thereby reducing the height of the protruding portion on the surface of the semiconductor module 1. Furthermore, stress in the disc spring 2 is reduced, thereby preventing the disc spring 2 from rotating backward.

[0049] <Variation of Embodiment 2>

[0050] In embodiment 2, as Figure 10 As shown, a tapered shape may be provided around the groove 1e to guide the outer peripheral portion 2d of the disc spring toward the groove 1e. With this configuration, the entire disc spring 2 can be brought substantially closer to the semiconductor module 1, thereby reducing the height of the protruding portion on the surface of the semiconductor module 1.

[0051] Furthermore, the modified example of the first embodiment may be applied to the second embodiment, etc., and the modified example of the second embodiment may be applied to the first embodiment, etc. For example, in the modified example 2 of the first embodiment ( Figure 3 ), it is also possible to implement the modified example of embodiment 2 ( Figure 10 ), a tapered shape is provided on the periphery of the second groove portion 1d to guide the outer peripheral portion 2d of the disc spring to the second groove portion 1d. In addition, for example, in this embodiment 2, it is also possible to Figure 11 As shown, the cross-sectional shape of the hole 2a of the disc spring 2 corresponds to the cross-sectional shape of at least a portion of the head 3a of the screw 3. As described above, the modifications of each embodiment can be appropriately applied to other embodiments, and the same applies to the third embodiment and thereafter.

[0052] <Implementation Method 3>

[0053] Figure 12 3 is a cross-sectional view showing the structure of a semiconductor device according to Embodiment 3 of the present invention. Components according to Embodiment 3 that are identical or similar to the above-described components are denoted by identical or similar reference numerals, and the description will focus on the different components.

[0054] In the third embodiment, the screw 3 includes a screw portion 3c integral with the disc spring 2 so as to fill the hole 2a of the disc spring 2. The screw 3 screws the semiconductor module 1 to the cooling unit 11. This structure eliminates the need for the head portion 3a of the screw 3, thereby reducing the height of the protruding portion on the surface of the semiconductor module 1.

[0055] <Implementation Method 4>

[0056] Figure 131 is a cross-sectional view showing the structure of a semiconductor device according to Embodiment 4 of the present invention. Hereinafter, components according to Embodiment 4 that are identical or similar to the above components are denoted by identical or similar reference numerals, and the description will focus on the different components.

[0057] Figure 13 The semiconductor device includes a semiconductor module 1, a disc spring 2, a cover 4, screws 5, and an insulating terminal block 7. The semiconductor module 1 is mounted on a cooling unit 11, which is a mounting body, by screws 5. The cooling unit 11 is connected to a ground potential.

[0058] In the fourth embodiment, the semiconductor module 1 includes an electrode terminal 1b protruding laterally and a ground terminal (not shown) protruding laterally in the same manner as the electrode terminal 1b. The electrode terminal 1b is, for example, a main terminal for conducting electricity other than the ground terminal. Figure 13 In the embodiment, the semiconductor module 1 has Figure 1 The same hole through which the screw 3 passes may be provided, but the same hole may be provided.

[0059] In the fourth embodiment, the disc spring 2 is a normal disc spring and does not have Figure 1 The concave portion 2 b and the convex portion 2 c are arranged on the upper surface of the semiconductor module 1 .

[0060] The cover 4 includes a first portion 4a and a second portion 4b. The first portion 4a faces the electrode terminal 1b of the semiconductor module 1. The second portion 4b faces the upper surface of the semiconductor module 1 and projects upward from the first portion 4a to accommodate the disc spring 2. Furthermore, the second portion 4b presses the disc spring 2 toward the semiconductor module 1.

[0061] Furthermore, in the fourth embodiment, the first portion 4a is an insulating molded article made of, for example, epoxy resin, and the second portion 4b is a metal component. With this structure, even when the second portion 4b is electrically connected to the ground terminal of the semiconductor module 1, the insulating first portion 4a can insulate the electrode terminal 1b from the ground terminal.

[0062] Screws 5 screw together the first portion 4a of the cover 4, the electrode terminals 1b of the semiconductor module 1, and the cooling unit 11. With this structure, the heads of the screws do not overlap the disc springs above the semiconductor module 1. Therefore, by making the thickness of the second portion 4b of the cover 4 smaller than the height of the screw heads, the height of the protruding portion on the surface of the semiconductor module 1 can be reduced. Furthermore, the screws 5 are screwed together with the cooling unit 11, which has a ground potential, via the insulating terminal block 7. With this structure, the insulating terminal block 7 insulates the electrode terminals 1b from the cooling unit 11.

[0063] <Variation 1 of Embodiment 4>

[0064] In embodiment 4, Figure 14 As shown, the first portion 4a and the second portion 4b of the cover 4 may be a single insulating molded product made of, for example, epoxy resin.

[0065] <Variation 2 of Embodiment 4>

[0066] At once Figure 15 In the semiconductor device according to the second modification of the present embodiment, a ground terminal 1f is provided instead of the electrode terminal 1b on the right side of the semiconductor device according to the first modification of the fourth embodiment. Figure 15 As shown, the semiconductor device may also include a metal plate 6 provided on the inner surface of the cover 4 and in contact with the ground terminal 1f of the semiconductor module 1. The material of the metal plate 6 is, for example, copper (Cu), aluminum (Al), etc. According to such a structure, a shielding effect can be obtained. Figure 15 In the example, since both the ground terminal 1f and the cooling unit 11 have a ground potential, the screw 5 screwed into the metal plate 6 and the ground terminal 1f may be screwed directly into the cooling unit 11 without passing through the insulating terminal block 7 .

[0067] <Variation 3 of Embodiment 4>

[0068] In the second variation of the fourth embodiment, Figure 16 As shown, the cover 4 is integrated with the disc spring 2. With such a structure, the assembly of the pressing mechanism in the semiconductor device is facilitated.

[0069] <Variation 4 of Embodiment 4>

[0070] In the second variation of the fourth embodiment, as Figure 17 As shown, the semiconductor module 1 may include a groove 1e for receiving the outer peripheral portion 2d of the disc spring 2. This configuration can suppress the height of the protrusion on the surface of the semiconductor module 1 and the inversion of the disc spring 2, similarly to the second embodiment.

[0071] In addition, although not shown in the figure, Figure 17 In the structure of the second embodiment, a tapered shape can be provided around the groove 1e to guide the outer peripheral portion 2d of the disc spring toward the groove 1e, similarly to the modified example of the second embodiment. With this structure, the entire disc spring 2 can be substantially brought closer to the semiconductor module 1, thereby reducing the height of the protruding portion on the surface of the semiconductor module 1.

[0072] Furthermore, the present invention can freely combine the various embodiments and various modifications, or can appropriately modify or omit the various embodiments and various modifications within the scope of the present invention.

[0073] While the present invention has been described in detail, the above description is in all aspects illustrative and the present invention is not limited thereto, and it is understood that numerous modifications not shown here are conceivable without departing from the scope of the present invention.

[0074] Description of the label

[0075] 1. Semiconductor module, 1a. First groove, 1b. Electrode terminal, 1d. Second groove, 1e. Groove, 1f. Ground terminal, 2. Disc spring, 2a. Hole, 2b. Concave, 2c. Protrusion, 2d. Outer periphery, 3. Screws, 5. 3a. Head, 3b. Root, 3c. Screw, 4. Cover, 4a. First portion, 4b. Second portion, 6. Metal plate.

Claims

1. A semiconductor device comprising: A semiconductor module having a first groove portion; A disc spring that is recessed from its hole to the periphery of the hole, thereby having a concave portion on the outer surface and a convex portion on the inner surface; and a screw that passes through the hole of the disc spring and the first groove of the semiconductor module to screw the semiconductor module to the mounted body; The head of the screw is received in the recess of the disc spring. The protrusions of the disc spring are all received in the first groove of the semiconductor module. The outer peripheral portion of the disc spring is in surface contact with the semiconductor module.

2. The semiconductor device according to claim 1, wherein The depth of the first groove of the semiconductor module is greater than or equal to the height of the protrusion of the disc spring.

3. The semiconductor device according to claim 1, wherein The semiconductor module further includes a second groove portion that receives an outer peripheral portion of the disc spring.

4. The semiconductor device according to claim 3, wherein The depth of the first groove portion is different from the depth of the second groove portion within a range in which the outer peripheral portion of the disc spring can press the semiconductor module.

5. The semiconductor device according to claim 1, wherein The cross-sectional shape of the hole of the disc spring corresponds to the cross-sectional shape of at least a portion of the head of the screw. The semiconductor device according to claim 5 , wherein: The cross-sectional shape of the hole of the disc spring corresponds to the cross-sectional shape of the entire head of the screw.

7. The semiconductor device according to claim 6, wherein The cross-sectional shape of the hole of the disc spring corresponds to the cross-sectional shape of the entire head of the screw and the base of the head of the screw.

8. The semiconductor device according to claim 1, wherein The cross-sectional shape of the first groove portion of the semiconductor module corresponds to the cross-sectional shape of at least a portion of the protrusion of the disc spring.

9. The semiconductor device according to claim 8, wherein The cross-sectional shape of the first groove portion of the semiconductor module includes a tapered shape.

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