Patent ID: 7947098
Filing Date: 2011-05-24
Classification: B01F,B24B,B24D,B29B,B29C

Abstract:
1. A method of forming a chemical mechanical polishing pad polishing layer, comprising: providing a mold; providing a liquid prepolymer material; providing a plurality of microspheres in an inert carrier gas; providing an inert purge gas; providing a mix head assembly, having a housing with at least one housing inlet and a housing outlet; a seal interfaced with the housing; and a rotating mixer with a shaft; wherein the rotating mixer is disposed within the housing; wherein the shaft extends out of the housing through the seal; and wherein the shaft has a passage therethrough with a shaft passage inlet and a shaft passage outlet to facilitate venting of the inert carrier gas and the inert purge gas out of the housing through the shaft passage; combining the liquid prepolymer material with the plurality of microspheres in the inert carrier gas in the housing, under the action of the rotating mixer, forming a mixture of liquid prepolymer and microspheres; supplying the inert purge gas to the housing; venting the inert carrier gas and the inert purge gas from the housing through the shaft passage; transferring the mixture of liquid prepolymer and microspheres through the housing outlet to the mold; allowing the mixture of liquid prepolymer and microspheres to solidify into a cake in the mold; and, deriving a chemical mechanical polishing pad polishing layer from the cake.