Small Sample Testing Technique for Solders

Abstract

This paper discusses a newly developed tensile testing, low cycle fatigue testing and creep testing technique for electronic materials solder. A investigate working group in Society of Materials Science, Japan established a making procedure for a small size specimen which has 3mm-diameter gage part and developed a testing technique for the small size specimen. Cooling rate of the melted solder for the small size specimen is controlled as under 10K/s by using cooling rate calculation equation developed in this study. The developed testing technique made it possible to conduct not only static tensile testing or creep rupture testing but also low cycle fatigue testing under strain control mode with the small size specimen. This paper also discusses the specimen size influence on static tensile strength, cyclic fatigue and creep properties of solders. There was no specimen size influence on the tensile strength for Sn-3.0Ag-0.5Cu. Although there was stress amplitude difference between the small size specimen and the bulk type specimen which has 10mm in diameter, there was no low cycle fatigue lives difference for Sn-3.0Ag-0.5Cu. Creep rupture time of Sn-3.0Ag-0.5Cu with small size specimen was almost same as that of the bulk type specimen.