High performance screen-printable silicone as selective hybrid IC encapsulant

An excellent solvent-, flux-, and detergent-resistant screen-printable silicone (SPS) with a modest curing temperature and excellent adhesion to gold-plated substrate has been developed. The author describes the material formulation of and the need for an encapsulant with the above properties. Microdielectrometry was used to define the precise SPS cure schedule; temperature-humidity-bias was used to qualify the material´s electrical performance; Auger spectroscopy and laser ionization mass spectrometry were used to further elucidate the crosslinking density and the interfacial interaction of the SPS and the encapsulated substrate. The high crosslinking density resulting from the addition of an aminosilane and high filler (fused silica) loading were shown to be the keys to a solvent-resistant silicon formulation