Inverted cell pad material for grinding, lapping, shaping and polishing

Abstract

A polishing pad material is provided with a cellular polymeric layer containing elongated cells normal to the major surfaces of the material, such that the cell openings on the polishing surface of the material comprise a majority of the surface area, and the cells have a mean diameter of about 50 to 200 microns with the diameter of the surface openings being preferably larger than the cell diameters below the surface. The cells are preferably cone-shaped and have a depth at least 1.5 times the diameter of the surface openings. The pad material is formed from a poromeric material, preferably polyurethane elastomer, with microporous cell walls having pore diameters less than 0.1 times the diameter of the cells. The polishing pad material may be made according to conventional poromeric technology, but instead of removing the usual top poromeric skin, the poromeric layer is inverted and the original bottom poromeric skin and any attached substrate are removed to open and expose the cells at a plane corresponding to their largest diameters.

Dependencies are inferred from the claim text.