High reliable and environmental friendly molding compound for CABGA(R) packages

In this study, four kind of epoxy resins (biphenyl, naphthol, multi-functional, and OCN type) have applied to molding compound for CABGA packages. Basic, thermal, and mechanical properties of all molding compounds were measured and compared with moldability (coplanarity and wire sweep) and reliability (moisture sensitivity level) in the CABGA packages. From factor study, it was clear that molding compound which had high Tg and low shrinkage represents low coplanarity of CABGA packages. Coplanarity of MAP-type CABGA package decreased with increasing Tg and decreasing shrinkage of molding compound. Especially, coplanarity of the said package was found to be linearly proportional to the difference of shrinkage between PCB substrate and molding compound at room temperature. In case of reliability, the amount of absorbed moisture and flexural modulus of molding compounds affected on moisture sensitivity level. Low moisture absorption and flexural modulus are profitable for high reliability-JEDEC Level 3, 30°C/60%RH/192 hours at reflow temperature 260°C