2003 年 6 巻 5 号 p. 420-427
To know the characteristic reliability of SnZn soldering joints, we investigated with the thermal fatigue life with CSP which has Sn-3Ag-0.5Cu solder balls, and the mechanical fatigue life of soldering joints between Cu or Au/Ni plating on Cu after environmental test. We found that the soldering joints at reflow temperature which is lower than the melting point of Sn-3Ag-0.5Cu solder, had satisfied thermal fatigue life. However the soldering joints between Cu platings, which stored in the high temperature and high humidity chamber, had short mechanical fatigue life.