A Numerical Simulation Study on Wetting and Bridging of SnAgCu Solder Liquid
With size and pitch of the solder pad decreasing, solder bridging become one of the most common and critical defect in the high-density assembly process. Optimized geometry of solder with its pad is the guarantee of manufacturing process. By means numerical simulation technology, the wetting behavior of SnAgCu solder liquid on structured surface consisting of solder pad and solder mask was investigated. The solder liquid separation condition, that the solder height must below one and third quarter of the width of nonwetting zone, was verified. The simulation results demonstrate the validity of the criteria.