Simulation analysis and optimization of pin failure of a CSOP-packaged devices

Surface mount technology solder joint reliability issue is the impact on the performance of surface mount components and the service life of the key problems, the main factors which influence the reliability of including the internal quality of welds, mechanical properties and loading conditions of solder joints. This paper mainly focused on the pins' failure of Ceramic Small Out-Line Package (CSOP) devices after the temperature cycling test in the quality uniformity inspection. The solder defect was excluded by the examination of pins' pretreating layer, pins' weldability test and process quality reliability test. Mechanical simulation was applied to analysis failure mechanism. It indicated that the major failure cause was the inappropriate matching of coefficient of thermal expansion (CTE) between devices and PCB, and the unreasonable pins' formation also resulted in the failure. A method of optimizing the pins' formation was proposed in this paper, and the results of experiments showed that the solution was effective.