Friction stir welding structure and power semiconductor device

• US 9,278,503 B2
• Filed: 08/09/2012
• Issued: 03/08/2016
• Est. Priority Date: 08/19/2011
• Status: Active Grant

• Current Assignee: Hitachi Astemo Ltd. (Hitachi, Ltd.)
• Original Assignee: Hitachi Automotive Systems Limited (Hitachi, Ltd.)
• Inventors: Hori, Toshio, Uraki, Keiichi, Higuma, Masato, Kaneko, Yujiro, Hirano, Satoshi, Sato, Akihiro
• Primary Examiner(s): Stoner, Kiley
• Application Number:
  US14/235,644
• Publication Number:
  US 20140210070A1
• Time in Patent Office: 1,307 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: B23K 20/122 using a non-consumable tool, e.g. friction stir welding
• CPC Class Codes: B23K 20/129 specially adapted for particular articles or workpieces
• CPC Class Codes: B23K 2101/40 Semiconductor devices
• CPC Class Codes: B23K 2103/10 Aluminium or alloys thereof
• CPC Class Codes: B32B 15/01 all layers being exclusively metallic making layered metal workpieces by pressure cladding B23K20/22; making coatings with a metallic material characterised by its composition C23C30/00
• CPC Class Codes: H01L 23/10 characterised by the material or arrangement of seals between parts, e.g. between cap and base of the container or between leads and walls of the container
• CPC Class Codes: H01L 23/34 Arrangements for cooling, heating, ventilating or temperature compensation ; Temperature sensing arrangements thermal treatment apparatus H01L21/00
• CPC Class Codes: H01L 23/473 by flowing liquids H01L23/4332, H01L23/4338 take precedence
• 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: Y10T 428/12493 Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]

Abstract

A friction stir welding structure is comprised of a first and a second member integrated into one piece by friction stir welding, and in which a thin section is formed along the friction stir weld section on at least one of either of the first and the second member.

Claims

1. A friction stir welding structure comprising:

first and second members formed into one piece by friction stir welding, wherein

a given section is formed along the friction stir weld section on at least one of the first and second members,

the first member and the second member are abutted together as a lap joint, and the abutted surface is friction stir welded,

the tensile strength S1 of the first member is set smaller than the tensile strength S2 of the second member, and

the relation between the thickness L1 of the given section of the first member and the weld depth D1 of the friction stir weld section is defined as;

(2×

S1)/(S1+S2)×

L1<

D1.

2. The friction stir welding structure according to claim 1, wherein

the first member is a rectangular plate, and the second member includes an opening sealed by the rectangular plate, and

a step is formed in the opening of the second member,

a weld section mounted on the step is formed on the outer peripheral edge of the first member,

the section where the outer peripheral edge of the first member abuts the step inner surface of the opening of the second member is welded across the entire circumference by friction stir welding, and

the given section is formed along the friction stir weld section of the first member.

3. The power semiconductor device including the friction stir welding structure according to claim 2, comprising:

a power semiconductor module;

a case that stores the power semiconductor module; and

a heat sink that cools the power semiconductor module,

wherein the second member is the case, and the first member is the heat sink that seals the opening of the second member.

4. A friction stir welding structure comprising:

first and second members formed into one piece by friction stir welding, wherein

a given section is formed along the friction stir weld section on at least one of the first and second members,

both the first and the second members contain given sections,

the first member and the second member are abutted and friction stir welded together as a butt joint,

the tensile strength S1 of the first member is set smaller than the tensile strength S2 of the second member, and

when the thickness of the given section of the first member is L1, and the thickness of the given section of the second member is L2, and the weld depth of the friction stir welding section is D1, the friction stir welding structure satisfies the relation;

(2×

S1)/(S1+S2)×

L1<

D1 and (S1/S2)×

L1<

L2.