Semiconductor device and method of manufacture thereof

• US 7,436,672 B2
• Filed: 04/20/2005
• Issued: 10/14/2008
• Est. Priority Date: 09/28/2004
• Status: Active Grant

• Current Assignee: Mitsubishi Electric Corporation
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Miyamoto, Noboru, Ushijima, Koichi, Hassan, Hussein Khalid
• Primary Examiner(s): Gandhi; Jayprakash N
• Assistant Examiner(s): HOFFBERG, ROBERT JOSEPH
• Application Number:
  US11/109,788
• Publication Number:
  US 20060067059A1
• Time in Patent Office: 1,273 Days
• Field of Search: 361/600, 361714-715, 361/700, 361/704, 361/707, 361709-710, 361/719, 361799-800, 361/816, 361/818, 165/80.3, 165/104.33, 165/185, 257/508
• US Class Current: 361/715
• CPC Class Codes: H01L 25/162 the devices being mounted on two or more different substrates
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H05K 7/1432 specially adapted for power drive units or power converters
• CPC Class Codes: H05K 7/14322 wherein the control and power circuits of a power converter are arranged within the same casing

Abstract

A transfer mold type power module (“TPM”) is provided with a projection at each of the four corners on its front main surface. The TPM is also provided a first screw hole at its center. A shielding plate is provided with a second crew hole in a position that corresponds to the first screw hole. A control substrate is provided with third screw holes in positions that correspond to the projections. The shielding plate and the TPM are joined by putting a first screw through the first and second screw holes and temporarily fastening the tip of the first screw by a temporary fastening member at the rear main surface of the TPM. The control substrate and the TPM are joined by second screws via the third screw holes.

Claims

1. A semiconductor device comprising:

a power module in which a power semiconductor element is sealed with resin, said power module having a first hole extending therethrough and a substantially planar top surface;

a control substrate for controlling said power module and having a second hole extending therethrough and aligned with said first hole of said power module; and

a shielding plate having a third hole extending therethrough and aligned with said first hole of said power module and said second hole of said control substrate, and having a substantially planar bottom surface mounted directly and entirely on said top surface of said power module via a fastener disposed through said first and third holes,

wherein said power module includes a structure for mounting said control substrate to said power module, said control substrate being mounted above said shielding plate via said structure.

2. The semiconductor device according to claim 1, wherein

said shielding plate is mounted on only a part of said top surface of said power module via said fastener,

said power module includes projections formed at locations on said top surface other than said part of said top surface on which said shielding plate is mounted and

said control substrate is joined to said projections.

3. The semiconductor device according to claim 2, wherein said power module is substantially rectangular, and said projections are respectively formed on corners of said power module.

4. The semiconductor device according to claim 2, wherein

said control substrate has a plurality of fourth holes extending therethrough, and said projections each have a fifth hole formed therein and extending through an upper portion thereof, each one of said fourth holes of said control substrate being respectively aligned with one of said fifth holes formed in said projections, and

said control substrate is fastened to said projections via another fastener disposed through each corresponding pair of one of said fourth holes of said control substrate and one of said fifth holes of said projections.

5. The semiconductor device according to claim 1, further comprising a temporary fastening member for temporarily fastening said fastener at a bottom surface of said power module to said top surface of said power module.

6. The semiconductor device according to claim 5, wherein said power module includes engagement parts on its side surfaces, so that side surfaces of a plurality of said power modules can be engaged via said engagement parts.

7. The semiconductor device according to claim 6, further comprising a plurality of said power modules, said plurality of said power modules being continuously engaged by said engagement parts.

8. The semiconductor device according to claim 7, further comprising a bus bar electrode for connection to electrode terminals of said plurality of power modules, wherein

said bus bar electrode includes external electrode terminals for connection to peripheral components and module side electrode terminals for connection to said electrode terminals, and

said module side electrode terminals are located in symmetry with respect to said external electrode terminals.

9. The semiconductor device according to claim 8, wherein

said bus bar electrode includes a plurality of partial bus bar electrodes, and

said partial bus bar electrodes are joined to insulating films interposed therebetween.

10. The semiconductor device according to claim 5, wherein said fastener is a screw, and said temporary fastening member is a nut made of resin or a vinyl tube.

11. The semiconductor device according to claim 1, wherein

said power module further includes a bus bar electrode connected to said power semiconductor element, and

said power semiconductor element and said bus bar electrode are sealed together with resin.

12. The semiconductor device according to claim 11, wherein

said power module further includes peripheral components connected to said bus bar electrode, and

said power semiconductor element, said bus bar electrode, and said peripheral components are sealed together with resin.

13. The semiconductor device according to claim 1, further comprising a cooling fin provided on a bottom surface of said power module opposite to said top surface of said power module.

14. The semiconductor device according to claim 13, wherein said control substrate mounted to said power module is configured to accommodate, while said shielding plate is mounted to said power module, a tool through said second hole to mount said cooling fin to said bottom surface of said power module via said fastener disposed through said first and third holes aligned with said second hole.

15. The semiconductor device according to claim 1, wherein the shielding plate provides a shielding effect for the control substrate.

16. The semiconductor device according to claim 15, wherein the shielding plate also functions as a pressure plate.

17. The semiconductor device according to claim 1, wherein the shielding plate prevents radiation noise from affecting the control substrate.

18. The semiconductor device according to claim 1, wherein

said first hole extends from a central portion of said top surface of said power module through a central portion of a bottom surface of said power module opposite to said top surface of said power module,

said third hole extends from a central portion of a top surface of said shielding plate through a central portion of said bottom surface of said shielding plate opposite to said top surface of said shielding plate, and

said fastener is disposed through said first and third holes respectively provided at the central portions of said power module and said shielding plate so as to mount said shielding plate on said power module by bringing said bottom surface of said shielding plate into contact with said top surface of said power module.

19. The semiconductor device according to claim 1, wherein said fastener is a screw.

20. The semiconductor device according to claim 1, wherein

the power semiconductor element is sealed with said resin by the transfer molding method, and

said shielding plate is connected to a ground line of said control substrate.

21. The semiconductor device according to claim 1, wherein said control substrate mounted to said power module is configured to provide access, while said shielding plate is mounted to said power module, to said fastener disposed through said first and third holes aligned with said second hole, via said second hole.

22. A method of manufacturing the semiconductor device recited in claim 1, comprising the steps of:

(a) mounting said shielding plate on said power module;

(b) mounting said control substrate on said power module; and

(c) conducting a function test on said power module with said shielding plate and said control substrate being mounted threreon.

23. The method of manufacturing the semiconductor device according to claim 11, further comprising the step of mounting a cooling fin on a bottom surface of said power module after said step (c).

24. A method of manufacturing the semiconductor device recited in claim 5, comprising the steps of:

removing said temporary fastening member; and

mounting a cooling fin by said fastener disposed in said first and third holes.