Influence mechanism of pad type on the shear performance of Sn3.0Ag0.5Cu/Cu solder joint

The influence mechanism of different pad types (SMD and NSMD) on the shear performance of Sn3.0Ag0.5Cu/Cu solder joint was investigated by experiment and Finite Element Analysis (FEA) method. The shear force of NSMD solder joint was significantly higher than SMD solder joint by using ball shear test method according to JSED22-B117A standard. The difference in shear force was attributed to the different distribution of stress of the solder joint by using different pad type during shear testing. The location of maximum vians stress in solder joint with NSMD pad changed from the right corner of joint to the boundary of substrate and pad with test time going on. However, the maximum stress always located at the right corner of joint and the end of ram for joint with SMD type pad. The different distribution of stress resulted to a distinct failure model of solder joint.