A process capability study: eliminating latent failures of surface mount multilayer ceramic capacitors from the wave solder process

This paper describes the test method and results of the inherent variation of preheat profiles in a wave solder machine for surface mount 1812 size multilayer ceramic capacitors (MLC). This study was undertaken to reduce the risk of latent failures that are found in 1812 size capacitors due to inadequate preheat levels in the wave soldering process. The results have shown that the inherent wave solder machine preheat variation is far less significant than the preheat variation from product design (component location to component location). This indicates that product design has a much larger effect on the peak preheat temperatures obtained for 1812 capacitors than the inherent variation of the wave solder machine