Quantification of lead-free solder fatigue by EBSD analysis

Abstract Since lead-free solder was adopted for in-vehicle electronic components, a sufficient number of years have passed to allow examining the condition of lead-free solder joints in components used in the field. For this paper, using an EBSD analysis technique, solder joint degradation analysis was conducted on specimens subjected to accelerated testing and field-aged components. Degradation indicators of the level of grain refining and the amount of strain in the Sn phase in solder were obtained from specimens subjected to accelerated testing. The analysis results of field-aged components revealed increases in the degradation indicators commensurate with the age of components, thereby we were able to estimate field stress from the recovered components.