Durability Properties Characterization of Sn62Pb36Ag2 Solder Alloy

Abstract

The cyclic durability properties of a near-eutectic Sn62Pb36Ag2 solder alloy are explored using a piezoelectric-actuated Thermo-Mechanical-Microstructural (TMM) test apparatus. The miniature test specimens are an Iosipescu-type shear configuration with a typical joint thickness of 180μm, so that significant length-scale effects are captured. Cyclic, total displacement-controlled tests are executed at room temperature and at various strain rates and amplitudes. A variety of failure models are employed to quantify the durability of this alloy, compared to the baseline Sn-Pb eutectic solder. Power-law relationships between the number of cycles to failure and three damage metrics (total strain, inelastic strain and hysteresis energy) are established for the Sn62Pb36Ag2 solder alloy. There is good agreement between the results presented here and other data in the literature for the inelastic strain and hysteresis energy models. The parameters of the total strain-based damage model do not agree well with other published data. A discussion of these results is included, along with details of recent developments in the test method used here, as well as other future work.