REAR PROTECTIVE AGENT FOR TAPE CARRIER AND MANUFACTURE OF TAPE CARRIER USING SAME

PURPOSE:To obtain a rear protective agent that is alkali-soluble, sufficiently flexible in thin application and highly strong, by using a copolymer of vinyl acetate and ethylenic unsaturated carboxylic acid of a specific mol ratio with average degree of polymerization within a specific range. CONSTITUTION:A copolymer of 98-85mol% of vinyl acetate and 2-15mol% of ethylenic unsaturated carboxylic acid, 200-1500 in average degree of polymerization, is used for the title rear protective agent. In manufacturing a tape carrier using such rear protactive agent, holes, such as device holes, are formed in a resin tape coated with adhesive, and a sheet of copper foil is applied thereto. Photoresist is applied to the front face of the resin tape, which is then subjected to mask exposure. The liquefied rear protective agent is applied to the rear face of the tape and dried. The copper foil is etched on the photoresist side to form a wiring pattern. Then the photoresist film on the front face of the resin tape and the rear protective agent film on the rear face are simultaneously removed.