One of the major failure mechanism of the solder joints used in surface mount components is a thermal fatigue fracture by the periodic temperature cycling and thermal gradient. There is a great increase in the heat dissipation per unit area, because there is a tendency in which surface mounted components used in electronic products become integrated and miniaturized. Therefore, fatigue fracture phenomenon induced by thermal gradient and temperature cycling are considered very important in the view of product reliability.
Generally, there are chamber cycling test and power cycling test for measuring material properties under thermal environment and investigating fatigue behavior. The former has a advantage that it can generate a wide temperature range and is easy for experiment, but it apply same boundary condition for all surfaces of specimen. The latter can copy a practical usage environment of packaging component and can be a precision experiment. In this research, moire equipment is used for measuring a whole field displacement of specimen and suggesting a fatigue life prediction method.
In this research power cycling tester using conduction is developed for measuring properties of a solder joint and investigating thermal fatigue behavior, and moire interferometry is used for measuring a displacement field of solder joint during a temperature cycle. As a result, the technique of thermal fatigue life prediction using moire interferometry is developed.
