A Study on the Thermal Fatigue Characteristics of Microelectronic Packaging Solder Joints

摘要

In Electronic Packaging, solder joints are in long-term condition of high temperature and cyclic strain state in the process of thermal cycle. The study on the behavior of the solder joints under thermal cycling at high temperature is therefore practically significant. The method of mount strain gages is used to measure the stress/strain hysteresis loops of the solder joints under thermal cycle. Results show the evidence for the interaction of creep and fatigue and shear moduli decrease along with the process. High sensitivity moire interometry method has been used to measure the residual thermal strain distribution of solder joints in different thermal cycling parameters. The experimental results showed that the mismatch of CTE between the two parts jointed by the solder joints results in large shear strains in the solder joints, and the strain distribution is not uniformity.