Patent ID: 7311862

Claim:
A method of manufacturing a chemical-mechanical polishing (CMP) pad comprising the steps of: (a) forming a layer of a polymer resin liquid solution; (b) inducing phase separation in the layer of polymer resin liquid solution to form an interconnected polymeric network comprising a continuous polymer-rich phase interspersed with a continuous polymer-depleted phase, the polymer-depleted phase comprising about 20 to about 90 percent of the combined volume of the separated phases, the phase separation being selected from the group consisting of a binodal decomposition, a spinodal decomposition, solvent-non-solvent induced phase separation, and a combination thereof; (c) solidifying the polymer-rich phase to form a porous polymer sheet defining an open network of substantially interconnected pores and having at least a portion of the polymer-depleted phase dispersed within the pores, the polymer sheet having a porosity in the range of about 20 to about 90 percent by volume, the network of pores comiprising pores having diameters in the range of about 0.01 to about 10 microns; (d) removing at least a portion of the polymer-depleted phase from the porous polymer sheet, wherein the step of removing the polymer-depleted phase is accomplished by a process selected from the group consisting of evaporation, solvent exchange, solvent stripping under vacuum, freeze drying and any combination thereof; and (e) forming a CMP pad from the porous polymer sheet.