Packaging Materials Today
Alpha Emission Rates for Curr ent Packaging Mater ials (counts/kh/cm2)
Packag e T yp e
Terrestrial Component (neutrons/khr/cm2)
Flip Chip packaging materials adjacent to devices have the lowest alpha emission materials in the industry today
Lead free interconnect materials (current Sn/Pb solder bump alternative) for flip chip bump is being evaluated. This will eliminate the lead based source upsets. Trace impurities in these new materials will contribute to emission at a much lower level than the current low alpha leads.
Currently all PBGA mold compound and encapsulant base epoxies have lower alpha emission rates. Fused Silica fillers (60 to 80% by volume) are added to the base epoxy and are the main contributors for alpha emission (20 c/khr/cm2). Low alpha filler choices (1 c/khr/cm2)are also available and will be evaluated for manufacturability and reliability.
6 0 k -12 0 k
Flip Chip PBGA
20 (1 for low alpha MC)
10 (Low Alpha Solder)
6 0 K -12 0 k
Presentation Name 76