Invention Grant
- Patent Title: Pb-free solder-connected structure and electronic device
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Application No.: US12773128Application Date: 2010-05-04
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Publication No.: US08503189B2Publication Date: 2013-08-06
- Inventor: Hanae Shimokawa , Tasao Soga , Hiroaki Okudaira , Toshiharu Ishida , Tetsuya Nakatsuka , Yoshiharu Inaba , Asao Nishimura
- Applicant: Hanae Shimokawa , Tasao Soga , Hiroaki Okudaira , Toshiharu Ishida , Tetsuya Nakatsuka , Yoshiharu Inaba , Asao Nishimura
- Applicant Address: JP Kanagawa
- Assignee: Renesas Electronics Corporation
- Current Assignee: Renesas Electronics Corporation
- Current Assignee Address: JP Kanagawa
- Agency: Antonelli, Terry, Stout & Kraus, LLP.
- Priority: JP9-346811 19971216
- Main IPC: H05K7/00
- IPC: H05K7/00 ; H01B5/00

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.
Public/Granted literature
- US20100214753A1 Pb-free solder-connected structure and electronic device Public/Granted day:2010-08-26
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