Chemically amplified photoresist for visible laser direct imaging

Abstract

The potential for circuit board fabrication using scanning laser direct-imaging (LDI) technology has become an area of significant interest. Described in this paper are the characteristics of a new photoresist, VLPR (or Visible Laser PhotoResist), designed specifically for LDI applications. This resist incorporates chemical amplification as a route to high sensitivity, and employs a new and unique sensitizing dye to induce the formation of strong acid. The polymeric component of the resist is a methacrylate terpolymer with pendant reactive groups which are cleaved by the action of acid. The material meets all functional requirements for circuit board fabrication by LDI. Further, this resist is the first member of a family of related materials which offer the potential for very general application in packaging device fabrication.