Dual-pore structure polishing pad

摘要

The polishing pad is useful for polishing at least one of magnetic, optical and semiconductor substrates. A porous polishing layer includes a dual porosity structure within a polyurethane matrix. The dual porosity structure has a primary set of pores having pore walls with a thickness of 15 to 55 μm and a storage modulus of 10 to 60 MPa measured at 25° C. In addition, pore walls contain a secondary set of pores having an average pore size of 5 to 30 μm. The porous polishing layer is either fixed to a polymeric film or sheet substrate or formed into a woven or non-woven structure to form the polishing pad.