PALLADIUM SURFACE FINISH FOR SOFT TOUCH SWITCHES AND HIGH DENSITY SMT ASSEMBLIES
Author: P. Seto Company: ChryslerHuntsvilleElectronics Date Published: 8/23/1998
Surface Mount International
Abstract: Palladium is a flat durable finish which is cost competitive with Hot Air Solder Leveled (HASL) surface finish, and is considerably less expensive than Ni/Au. The shelf life and ability to withstand multiple thermal cycles without degradation of the solderable surface offers distinct advantages over lower cost Organic Solder Protestants (OSP’S). The flatness of palladium is much better than HASL and the availability of a matte or gloss finish is useful fortailoring machine vision performance. Measurement of the coating is possible with conventional X-Ray Fluorescence (xRF) and is reproducible to +/- 1.0 microinch for coatings in the 3,0-9.0 microinch range. Palladium surface finish is suitable for wave solder, solder paste reflow, and soft touch switch applications.