Advanced fillers for electronics encapsulation and electro-magnetic compatibility (EMC)

EMC self-shielding in electronics packaging has become possible with the use of specially configured Ferro-silicate powder, which is a by-product from another process. Present transfer moulded microelectronics packages dominate the packaging of the multi-billion semiconductor devices manufactured annually. These make use primarily of epoxy thermosets which are compounded with compatible inorganic particle "fillers" up to 85% by weight. Further, the electronics equipment businesses make use of plastic enclosures in almost every application, from commodity to complex systems. Analyses have shown that the special ferro-silicate powder is chemically, physically, mechanically and radioactively suited as a filler both with thermosets and thermoplastic composites. The substitution of existing inorganic fillers by appropriately processed ferro-silicate powder is an good opportunity as a significant differentiator filler. Research and development results show that a processed ferro-silicate powder is compatible with the polymer and the moulding process, does not damage or short-circuit the semiconductor chip surface, and provides more than the desired EM shielding ranging from 10 dB up to 90 dB. Microfocus X-ray inspection has confirmed uniformity of particle dispersion resulting from the compounding and moulding processes used. Scanning Acoustic Microscopy has confirmed there are no abnormal delaminations in the moulded packages and enclosures. Electrical measurements have confirmed that the compounding and moulding processes did not result in shorting of the active devices or cause other performance problems as the ferro-silicate is enhanced by further chemical treatments. Reliability testing with Highly Accelerated Stress Test (HAST) of QFPs have demonstrated reliability with no failures during the equivalent of 20 years in tropical climates.