Method of selectively releasing plastic molding material from a surface

摘要

A method of making a transfer molded chip carrier. A semiconductor device (10) is first electrically and mechanically attached to a substrate (12). The substrate (12) is then treated by sputter etching so that it will provide good adhesion between the substrate and a molding compound (18) that is subsequently molded to the substrate (25). Portions of the treated substrate are then selectively contaminated in order to reduce the adhesion between these selected portions of the substrate and the molding compound. The molding compound is then formed around the semiconductor device so as to encapsulate it and also part of the surface of the substrate. Portions (20) of the transfer molded material that were molded over the selectively contaminated portions of the substrate (12) are then removed by breaking away.