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. 04, 2010
Filed:
Jan. 13, 2006
Hanae Shimokawa, Yokohama, JP;
Tasao Soga, Fujisawa, JP;
Hiroaki Okudaira, Yokohama, JP;
Toshiharu Ishida, Fujisawa, JP;
Tetsuya Nakatsuka, Yokohama, JP;
Yoshiharu Inaba, Tachikawa, JP;
Asao Nishimura, Kokubunji, JP;
Hanae Shimokawa, Yokohama, JP;
Tasao Soga, Fujisawa, JP;
Hiroaki Okudaira, Yokohama, JP;
Toshiharu Ishida, Fujisawa, JP;
Tetsuya Nakatsuka, Yokohama, JP;
Yoshiharu Inaba, Tachikawa, JP;
Asao Nishimura, Kokubunji, JP;
Renesas Technology Corp., Tokyo, JP;
Abstract
Provided are a bonded structure by a lead-free solder and an electronic article comprising the bonded structure. The bonded structure has a stable bonding interface with respect to a change in process of time, an enough strength and resistance to occurrence of whiskers while keeping good wettability of the solder. In the bonded structure, a lead-free Sn—Ag—Bi alloy solder is applied to an electrode through an Sn—Bi alloy layer. The Sn—Bi alloy, preferably, comprises 1 to 20 wt % Bi in order to obtain good wettability of the solder. In order to obtain desirable bonding characteristics having higher reliability in the invention, a copper layer is provided under the Sn—Bi alloy layer thereby obtaining an enough bonding strength.