No-clean polymer flux evaluations and its impact on BGA solder joint quality and board level reliability

In the automotive industry, electronic systems are expected to perform well under harsh reliability conditions. There is an emphasis to continuously develop ball grid array (BGA) IC packages that perform increasingly well with respect to board level temperature cycling reliability. This paper is a study of three No-Clean Polymer Flux (NCPF) materials and evaluation of their performance relative to a standard water-soluble flux. The study was targeted to evaluate NCPF´s effect on processability, package ball grid array (BGA) solder joint quality and more importantly, its effect on temperature cycling reliability on board. Results showed that NCPFs generally performed comparatively on par or better than standard water-soluble flux. The NCPF variant selected for board level temperature cycling reliability test proved to have a positive impact in improving BGA solder joint reliability.