Bumping technologies of fine-pitch BGA components

The assembling technology of fine-pitch Ball Grid Arrays (BGAs) is used for high-end applications such as technology of very high density circuits and package-on-package structures. Vapor phase soldering is a perspective technology, but as it is still not very widespread in the industry and in research laboratories, there are a lot of things to examine to standardize the process and to get more experiences. SAC solder bumps made with different technologies were compared to each other and to bumps of commercial BGA components. Another aim was to determine the limits of our laboratory facilities in bumping and PWB technologies. Bumping experiments were carried out on model BGA components with stencil printing, reflowed with vapor phase and with applying solder with mini-wave selective soldering equipment. The optimization of the solder amount and the appropriate technology was in the focus of our research. To have acceptable, high, uniform and good quality bumps, we developed these processes with parameter optimization.