公开(公告)号：EP1275463A3

公开(公告)日：2003-02-12

申请号：EP02011162.1

申请日：1998-12-09

Applicant: Hitachi, Ltd.

Inventor： Shimokawa, Hanae, Hitachi,Ltd., Int. Propt. Group ,  Soga, Tasao, Hitachi,Ltd., Int. Propt. Group ,  Okudaira, Hiroaki, Hitachi,Ltd., Int. Propt. Group ,  Ishida, Toshiharu, Hitachi,Ltd., Int. Propt. Group ,  Nakatsuka, Tetsuya, Hitachi,Ltd., Int.Propt.Group ,  Inaba, Yoshiharu, Hitachi,Ltd., Int.Propt.Group ,  Nishimura, Asao, Hitachi,Ltd., Int.Propt.Group

IPC: B23K1/20 ,  B23K35/26 ,  H05K3/34 ,  H01L23/50 ,  C22C13/02

CPC classification number: H05K1/181 ,  B23K1/0016 ,  B23K35/004 ,  B23K35/007 ,  B23K35/262 ,  B23K2201/40 ,  H01L23/488 ,  H01L23/49811 ,  H01L23/532 ,  H01L24/29 ,  H01L2224/83101 ,  H01L2924/01322 ,  H01L2924/15747 ,  H05K3/3426 ,  H05K3/3463 ,  H05K2201/10909 ,  Y02P70/613 ,  Y10T29/49144 ,  Y10T29/49149 ,  Y10T29/49169 ,  Y10T428/12708 ,  Y10T428/12715 ,  H01L2924/00

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.