Authors: Harry Schoeller, Ph.D. and Michael Meilunas Company: Universal Instruments Corporation Date Published: 10/13/2013
Abstract: With 0.3mm pitch technology being integrated into the latest designs for smart phones/tablets and on the horizon for many other applications, rework is a major concern for high volume production. One of the steps to successfully adopting a high volume 0.3mm pitch process is developing a robust rework and re-balling procedure. The focus of this investigation is to develop a rework process using a standard rework procedure which could be easily adopted in a high volume manufacturing environment. The performance of reworked assemblies is compared to non-reworked assemblies in both drop/shock and thermal cycling accelerated life testing. The component solder joint microstructures are also compared in terms of Sn grain structure and IMC thickness. Comparison of the reworked and non-reworked assemblies shows no significant difference in N63 life. Failure analysis of the drop tested assemblies found different failure modes for the reworked and non-reworked assemblies.
0.3mm pitch BGA, rework, re-ball, drop test, thermal cycling