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:
May. 05, 2009
Filed:
Jan. 04, 2006
Ryouichi Kajiwara, Hitachi, JP;
Kazutoshi Itou, Hitachi, JP;
Hidemasa Kagii, Takasaki, JP;
Hiroi Oka, Tamamura, JP;
Hiroyuki Nakamura, Maebashi, JP;
Ryouichi Kajiwara, Hitachi, JP;
Kazutoshi Itou, Hitachi, JP;
Hidemasa Kagii, Takasaki, JP;
Hiroi Oka, Tamamura, JP;
Hiroyuki Nakamura, Maebashi, JP;
Renesas Technology Corp., Tokyo, JP;
Abstract
Pb free solder is used in die bonding. A thermal stress reduction plate is disposed between a semiconductor chip and a die pad made of a Cu alloy. The semiconductor chip and the thermal stress reduction plate are joined and the thermal stress reduction plate and the die pad are joined by a joint material of Pb free solder having Sn—Sb—Ag—Cu as its main constituent elements and having a solidus temperature not lower than 270° C. and a liquidus temperature not higher than 400° C. Thus, die bonding can be performed using the Pb free solder without generating any chip crack.