LFBGA273 Die Crack Reduction through Mold Process Improvement

In the changing package portfolio of ST Calamba from a major HVQFN plant to a BGA plant, one of the most complex and highest volume package lead type was LFBGA273. This was successfully transferred and qualified to our site but during the large scale volume production it encountered a major quality excursion which is die crack detected at test but was pinpointed to be encountered at mold process. This technical paper will be utilizing DMAIC as the strategy in solving this problem. With a very extensive defect analysis to define the failure mechanism and sound simulation to replicate problem lead to concrete actions such as mold cleaning process enhancement and input variable controls to significantly reduce die crack occurrence from reaching test and permanently addressing sources at assembly.