Patent ID: 6284114
Filing Date: 2001-09-04
Classification: B24B,B24D,C09D,H01L

Abstract:
A method of making a porous polishing pad material for a polishing pad, the method comprising electrophoretic deposition by immersing spaced apart electrodes in a bath, and while mixing the bath, impressing the electrodes with controlled electrical conditions, the method further comprising the steps of:immersing spaced apart electrodes in a bath having polymeric particles and water;impressing the electrodes with the controlled electrical conditions that consist of, a controlled voltage difference across the electrodes, and 4 controlled current flow through the electrodes;depositing the polymeric particles on one of the electrodes to form a polymeric mass while generating gaseous bubbles within the polymeric mass, which bubbles open at an exterior surface of the polymeric mass to provide a porous polishing pad material having pores therein that open at an exterior polishing surface on the polishing pad material; andvarying one of the controlled electrical conditions over a time duration as a thickness of the polymeric mass increases to increase the lengths of the bubbles transverse to the thickness of the polymeric mass.