Life prediction of lead alloy based on multi-failure criteria

Abstract

The aim of the study is to carrying out a series of experimental reliability tests for lead solder alloy Sn63Pb37 regarding to the so-called model of damage accumulation. In spite of Sn63Pb37 is prohibited in mostly cases by RoHS directive it is still used in lots of electronic devices which have influence on human life safety e.g. life-support machines, airplanes etc. That's why authors decided to examine the behavior of this solder alloy. Obviously the proposed method can be also used with lead-free solder alloys as well. The research is concerned on an identification of important solder alloys parameters and properties, which determine the description of solder joints reliability, especially in the microscale. In order to extract an essential properties of solder alloy, measurements will be executed mainly for the analysis of conventional individual failure modes i.e. creep, fatigue. Additionally an integrated mode, typical for the multi-failure criteria, i.e. creep plus fatigue, will be taken into account, which helps studying an appropriate model of damage accumulation and thereby for more accurate analysis and reliability forecasting due to an existence of multi-failure modes. A confirmation of the validity of the above-mentioned hypothesis is that results and tests, performed by the authors, indicate a significance of multi-failure on behavior and reliability parameters solder alloys in microscale. This requires a development of appropriate models and measuring techniques what will effect in improved quality of solder joints used in modern electronic devices. Thereby it will be able to increase the lifespan, i.e. reliability of these electronic devices, which are used in the processes under severe ambient conditions (dust, high humidity, high temperatures, mechanical stress), e.g. medical, automotive, military or airport industry.