Evaluation of Non-proportional Multiaxial Fatigue Strength of Lead-free Solder with Elements Addition

Abstract

The effect of element addition on creep and fatigue properties of Sn1.0Ag0.7Cu solder with addition of nickel, germanium and bismuth are reviewed. Element additions imporove creep properties although those deteriorate fatigue properties. From above results, necessity of non-proportional multiaxial fatigue tests are discussed. The load cell with high sensitivity was designed by making to detect small load during fatigue test was developed by making the strain detection part hollow circular. The inner diameter and the outer diameter of the load cell satisfying the condition that excessive strain does not occur regardless of high sensitivity was determined by strength calculation.