The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 20, 2007
Filed:
Nov. 29, 2005
Koji Sasaki, Tsuchiura, JP;
Shinji Hiramitsu, Kashiwa, JP;
Tadaaki Kariya, Tokai, JP;
Satoshi Matsuyoshi, Takahagi, JP;
Ryouichi Kajiwara, Hitachi, JP;
Shosaku Ishihara, Chigasaki, JP;
Koji Sasaki, Tsuchiura, JP;
Shinji Hiramitsu, Kashiwa, JP;
Tadaaki Kariya, Tokai, JP;
Satoshi Matsuyoshi, Takahagi, JP;
Ryouichi Kajiwara, Hitachi, JP;
Shosaku Ishihara, Chigasaki, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A semiconductor device is provided, in which buffer layers having a coefficient of linear expansion of 3×10−6/° C. to 8×10−6/° C. are joined to upper and lower surfaces of a silicon chip through a Pb-free solder having a thickness of not more than 0.05 mm and a melting point of not less than 250° C. The upper surface of the upper buffer layer and the lower surface of the lower buffer layer are respectively joined to a lead and a base through Pb-free solders having a thickness of not less than 0.15 mm and a melting point of not less than 250° C.