PROCESS FOR PREPARING FOAMED POLYURETHANE POLISHING PAD FOR FINE POLISHING TO IMPROVE FLATNESS OF PAD

摘要

PURPOSE: A process for preparing a foamed polyurethane polishing pad for fine polishing is provided to generate bubbles in a sheet of polyurethane foam without a separate hollow sphere for generating bubbles. CONSTITUTION: A foamed layer(3) of polyurethane resin having various bubbles(2) stacks on a substrate(1). To form a grinding pad, a grinding material layer having the mixture of the adhesive and grinding material is applied onto the foamed layer. The polyurethane resin foam is served as the grinding pad. The grinding material in the grinding material layer(4) is 10 to 40 micron in diameter. The polyurethane resin foamed layer is foamed by adding 10 to 50wt% of the grinding material to the resin into the polyurethane resin or by mixing active nitrogen containing compound containing the grinding material with liquid polyurethane pre-polymer.