Lift-Off Process for Metallizing Multilayer Ceramic Substrates Using Alumina-Based Paste As a Resist
Original Publication Date: 1987-Mar-01
Included in the Prior Art Database: 2005-Feb-01
This invention discloses a method and materials for forming stencils of circuit patterns, on ceramic substrates, capable of withstanding metal deposition at temperatures higher than normally tolerated by common, polymeric resist materials. The stencil is written by a laser beam into a deposited layer of a paste or slurry consisting of a suitable inorganic powder such as alumina, thermally depolymerizable binders such as polyvinyl butaryl, polymethyl methacrylate, etc., and volatile solvents commonly used in preparing such slurries or pastes. Typically such slurries or pastes will be composed of 60-70% by weight of the inorganic powder (e.g., alumina), 5-10% by weight of the polymeric binder (e.g., polymethyl methacrylate), with the solvent (e.g., amyl acetate) making up the remainder.