Thermally Prepared Palladium-Silica Catalytic Laminates
Original Publication Date: 1988-Jan-01
Included in the Prior Art Database: 2005-Feb-14
A palladium on silicon dioxide catalyst is prepared by thermal means and incorporated in the epoxy resin of circuit board laminates. The particle size is much smaller than that of a corresponding system in which palladium is supported on kaolin clay, and the catalyst is characterized by fewer ionic impurities and a higher proportion of palladium in the zero valence, catalytic state. A fumed silica (silicon dioxide) is employed having surface area of 200 square meters per gram and primary particle size of 12 nm. The dielectric constant is approximately 3.8 at 100 mHz. Fifty grams of this fumed silica is dispersed by mechanical stirring in just enough distilled water to provide a thick suspension. In a separate vessel 4.17 grams of palladium chloride is dissolved in 50 ml of hydrochloric acid of 50 percent by volume.