Power module including first and second sealing resins

• US 9,497,873 B2
• Filed: 07/10/2013
• Issued: 11/15/2016
• Est. Priority Date: 08/09/2012
• Status: Active Grant

• Current Assignee: Hitachi Astemo Ltd. (Hitachi, Ltd.)
• Original Assignee: Hitachi Automotive Systems Limited (Hitachi, Ltd.)
• Inventors: Takagi, Yusuke, Matsushita, Akira, Yoshinari, Hideto, Tsuyuno, Nobutake
• Primary Examiner(s): PAPE, ZACHARY
• Application Number:
  US14/419,013
• Publication Number:
  US 20150245523A1
• Time in Patent Office: 1,224 Days
• US Class Current: 1/1
• CPC Class Codes: H01L 2224/0603 Bonding areas having different sizes, e.g. different heights or widths
• CPC Class Codes: H01L 2224/32245 the item being metallic
• CPC Class Codes: H01L 2224/33181 On opposite sides of the body
• CPC Class Codes: H01L 2224/40137 the bodies being arranged next to each other, e.g. on a common substrate
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 23/051 another lead being formed by a cover plate parallel to the base plate, e.g. sandwich type
• CPC Class Codes: H01L 23/24 solid or gel at the normal operating temperature of the device H01L23/3135 takes precedence
• CPC Class Codes: H01L 23/3135 Double encapsulation or coating and encapsulation
• CPC Class Codes: H01L 23/3142 Sealing arrangements between parts, e.g. adhesion promotors
• CPC Class Codes: H01L 23/42 Fillings or auxiliary members in containers or encapsulations selected or arranged to facilitate heating or cooling
• 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 24/73 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 25/07 the devices being of a type provided for in group H01L29/00
• CPC Class Codes: H01L 25/072 the devices being arranged next to each other
• CPC Class Codes: H01L 25/18 the devices being of types provided for in two or more different subgroups of the same main group of groups H01L27/00 - H01L33/00, or in a single subclass of H10K, H10N
• 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 2924/1305 Bipolar Junction Transistor [BJT]
• CPC Class Codes: H01L 2924/13055 : Insulated gate bipolar transistor [IGBT]
• CPC Class Codes: H01L 2924/13091 : Metal-Oxide-Semiconductor Field-Effect Transistor [MOSFET]
• CPC Class Codes: H01L 2924/181 : Encapsulation
• CPC Class Codes: H02M 7/003 : Constructional details, e.g. physical layout, assembly, wiring or busbar connections
• CPC Class Codes: H05K 5/062 : sealed by a material injected between a non-removable cover and a body, e.g. hardening in situ
• CPC Class Codes: H05K 7/20409 : Outer radiating structures on heat dissipating housings, e.g. fins integrated with the housing
• CPC Class Codes: H05K 7/20418 : the radiating structures being additional and fastened onto the housing

Abstract

Sealing force between a metal case and a power semiconductor module is improved. In a power semiconductor module 3, peripheral side surfaces of power semiconductor devices 31U and 31L and conductor plates 33 to 36 are integrated by being covered with a first sealing resin 6. An oxide layer (rough surface layer) 46 is formed on an inner surface of a metal case 40. A fluid resin material is injected into a space S between the oxide layer 46 provided to the metal case 40 and a power semiconductor module 30, and then a second sealing resin 52 is formed. The second sealing resin 52 fills dents of the oxide layer 46, and therefore sealing force improves.

Claims

1. A power module, which is used in a power converter and mutually converts DC and AC, comprising:

a power semiconductor module comprising a pair of conductor plates, a semiconductor device disposed between the conductor plates, and a first sealing resin covering side surfaces of the pair of conductor plates, the power semiconductor module being integrated by the first sealing resin;

a metal case comprising a heat dissipation unit on an outer surface thereof and a storage unit storing the power semiconductor module; and

a second sealing resin provided on an outer peripheral side of the first sealing resin of the power semiconductor module stored in the metal case, a side surface of the second sealing resin adhering to an inner surface of the metal case,

wherein a rough surface layer for improving adhesiveness with the second sealing resin is provided at least on a region opposing the side surface of the second sealing resin on the inner surface of the metal case, and the second sealing resin fills dents of the rough surface layer,

wherein an oxide layer is formed on an outer side surface of the metal case, and

wherein the metal case comprises;

a frame including an opening; and

a heat dissipation fin plate formed of a material different from that of the frame and including a heat dissipation fin bonded to a periphery of the opening of the frame,

the oxide layer is formed on outer side surfaces of the frame and the heat dissipation fin plate, and

the thickness of the oxide layer formed on the outer side surface of the frame and the thickness of the oxide layer formed on the outer side surface of the heat dissipation fin plate are different.

2. The power module according to claim 1, wherein the second sealing resin is formed by injecting a fluid resin material.

3. The power module according to claim 2, wherein the rough surface layer is an oxide layer.

4. The power module according to claim 3, wherein at least a region including the rough surface layer is formed of aluminum-based metal, and the rough surface layer is formed of an anodized layer of aluminum-based metal.

5. The power module according to claim 1, wherein the rough surface layer is formed by a structure in which irregularities are formed on an inner side surface of the metal case.

6. The power module according to claim 1, wherein the metal case comprises:

an oxide layer formed at least on an outer surface of a joint between the frame and the heat dissipation fin plate.

7. The power module according to claim 1, wherein

the heat dissipation fin plate is formed of a material having a higher heat dissipation performance than that of the frame.

8. The power module according to claim 1, wherein the thickness of the rough surface layer is 0.5 to 30 μ

m.

9. The power module according to claim 1, wherein the oxide layer is an anodized layer.

10. The power module according to claim 1, wherein, in the oxide layer formed on the outer side surface of the frame and the oxide layer formed on the outer side surface of the heat dissipation fin plate, a part of the thinner oxide layer is removed and becomes a ground potential connection unit.