Process Development of micro-bump flip chip bonding with Non-Conductive Film

Non-Conductive Film (NCF) is one of the packaging technology used for micro-bump flip chip bonding beside capillary underfill. The bonding process used with the NCF need to be optimized to avoid NCF fillet entrapment inside the solder material and also to ensure good solder interconnects. The process development of forming solder interconnects for die stacking should be carried out without subjecting too much thermal loading to the solder joint. The developed bonding process had demonstrated its robustness through non-bias highly accelerated stress test (HAST) at 130°C/85% relative humidity for 96hr.