Power semiconductor device

• US 20030213979A1
• Filed: 03/10/2003
• Published: 11/20/2003
• Est. Priority Date: 03/08/2002
• Status: Active Grant

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Nakajima, Dai, Kashiba, Yoshihiro, Chuma, Hideaki
• Granted Patent: US 6,979,843 B2
• Time in Patent Office: Days
• US Class Current: 257/200
• CPC Class Codes: H01L 2224/45015 being circular
• CPC Class Codes: H01L 2224/45124 Aluminium (Al) as principal constituent
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/48472 the other connecting portion not on the bonding area also being a wedge bond, i.e. wedge-to-wedge
• CPC Class Codes: H01L 2224/73219 Layer and TAB connectors
• CPC Class Codes: H01L 2224/73221 Strap and wire connectors
• CPC Class Codes: H01L 23/427 Cooling by change of state, e.g. use of heat pipes by liquefied gas H01L23/445
• CPC Class Codes: H01L 23/4334 Auxiliary members in encapsulations H01L23/49568 takes precedence
• CPC Class Codes: H01L 23/49562 for devices being provided for in H01L29/00
• CPC Class Codes: H01L 24/45 of an individual wire connector
• CPC Class Codes: H01L 24/48 of an individual wire connector
• CPC Class Codes: H01L 24/73 Means for bonding being of different types provided for in two or more of groups H01L24/10, H01L24/18, H01L24/26, H01L24/34, H01L24/42, H01L24/50, H01L24/63, H01L24/71
• CPC Class Codes: H01L 24/91 Methods for connecting semiconductor or solid state bodies including different methods provided for in two or more of groups H01L24/80 - H01L24/90
• 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 2924/00012 Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/01004 Beryllium [Be]
• CPC Class Codes: H01L 2924/01005 Boron [B]
• CPC Class Codes: H01L 2924/01006 Carbon [C]
• CPC Class Codes: H01L 2924/01013 : Aluminum [Al]
• CPC Class Codes: H01L 2924/01014 : Silicon [Si]
• CPC Class Codes: H01L 2924/01019 : Potassium [K]
• CPC Class Codes: H01L 2924/0102 : Calcium [Ca]
• CPC Class Codes: H01L 2924/01023 : Vanadium [V]
• CPC Class Codes: H01L 2924/01029 : Copper [Cu]
• CPC Class Codes: H01L 2924/01033 : Arsenic [As]
• CPC Class Codes: H01L 2924/01042 : Molybdenum [Mo]
• CPC Class Codes: H01L 2924/01058 : Cerium [Ce]
• CPC Class Codes: H01L 2924/01068 : Erbium [Er]
• CPC Class Codes: H01L 2924/01075 : Rhenium [Re]
• CPC Class Codes: H01L 2924/01082 : Lead [Pb]
• CPC Class Codes: H01L 2924/1301 : Thyristor
• CPC Class Codes: H01L 2924/15747 : Copper [Cu] as principal constituent
• CPC Class Codes: H01L 2924/15787 : Ceramics, e.g. crystalline carbides, nitrides or oxides
• CPC Class Codes: H01L 2924/181 : Encapsulation
• CPC Class Codes: H01L 2924/1815 : Shape
• CPC Class Codes: H01L 2924/18301 : being an anchoring portion, i.e. mechanical interlocking between the encapsulation resin and another package part
• CPC Class Codes: H01L 2924/19107 : off-chip wires
• CPC Class Codes: H01L 2924/2076 : equal to or larger than 100 microns
• CPC Class Codes: H01L 2924/351 : Thermal stress

Abstract

A power semiconductor device that uses a lead frame for making connection to a semiconductor device and has a structure less subject to fatigue failure at the connection part of the lead frame. A mold resin of a casing (14) is used for integrally covering the lead frame (6, 7, 13), semiconductor device (1), and metal block (15) serving as a substrate mounting the semiconductor device (1). The mold resin surrounding the lead frame (6) and semiconductor device (1) strengthens the joint therebetween, resulting in the power semiconductor device less subject to fatigue failure at the connection part of the lead frame (6).

Claims

1. A power semiconductor device comprising:

a semiconductor device having a top surface and a bottom surface;

a metal block fixed on said bottom surface of said semiconductor device;

a lead frame fixed on said top surface of said semiconductor device; and

a casing of a mold resin integrally covering said semiconductor device, said metal block and said lead frame.

2. The power semiconductor device according to claim 1 wherein

part of said lead frame is exposed from said casing as an external electrode, and

said external electrode is disposed at a location projecting from a main surface of said casing in a direction normal to and away from a plane of said metal block on which said semiconductor device is fixed.

3. The power semiconductor device according to claim 2 wherein

said external electrode is disposed at a point inwardly from a side end part of said casing in said main surface of said casing.

4. The power semiconductor device according to claim 2 wherein

part of said casing projects from said main surface thereof,

said external electrode is disposed on said part of said casing,

an air-gap extending to said external electrode is disposed inwardly of said part of said casing, and

a step is disposed on a wall surface of said part of said casing facing to said air-gap.

5. The power semiconductor device according to claim 1 wherein

a projection is disposed on a plane of said metal block on which said semiconductor device is fixed.

6. The power semiconductor device according to claim 1 wherein

part of said lead frame is exposed from a main surface of said casing as a radiation part.

7. The power semiconductor device according to claim 6 wherein

said radiation part is a recessed area provided in said lead frame, a bottom part of said recessed area being fixed on said top surface of said semiconductor device.

8. The power semiconductor device according to claim 6 wherein

other metal block is fixed on said radiation part.

9. The power semiconductor device according to claim 8 wherein

an air-gap capable of holding a refrigerant is disposed in said other metal block.

10. The power semiconductor device according to claim 1 wherein

an air-gap capable of holding a refrigerant is disposed in said metal block.

11. The power semiconductor device according to claim 1 wherein

there are plural sets of said semiconductor device, said metal block, and said lead frame, and

all of said plural sets are integrally covered with said mold resin of said casing.

12. The power semiconductor device according to claim 1 further comprising:

a heat sink on a side of the surface of said casing on which said metal block is disposed.

13. The power semiconductor device according to claim 1 wherein

said mold resin has a coefficient of linear expansion in the range of ±

20% different from that of said metal block.