Polyurethane composition for cmp pads and method of manufacturing same
AssigneePraxair S.T. Technology, Inc.
InventorsYong Zhang, David Huang, Lu Sun
Life of this patent
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Abstract
Polyurethane composition based on a certain polyether and polyester prepolymer reaction mixture, wherein the composition is utilized in manufacturing chemical mechanical polishing/planarizing (CMP) pads. The CMP pads have low rebound and can dissipate irregular energy as well as stabilize polishing to yield improved uniformity and less dishing of the substrate.
Claims23
A polyurethane chemical mechanical polishing pad derived from a polyether/polyester based prepolymer reaction mixture, comprising:
- (a) toluene diisocyanate (TDI)-terminated polytetramethylene ether glycol based prepolymer in an amount of about 60-80 weight percent (wt %) based on the total weight of prepolymer mixture;
- (b) toluene diisocyanate (TDI)-terminated ethylene adipate polyester prepolymer in an amount of about 40-20 weight percent (wt %), wherein the weight percent based on the total weight of prepolymer mixture;
- (c) an effective amount of surfactant and curative, respectively, and
- (d) a foaming agent introduced into the reaction mixture to form said polishing pad, wherein the resulting polishing pad has a density ranging from about 0.6 to about 0.95 g/cc.
A method of making a polyurethane chemical mechanical polishing pad derived from a polyether/polyester based prepolymer reaction mixture, comprising:
- (a) mixing toluene diisocyanate (TDI)-terminated polyether prepolymer in an amount of about 60-80 weight percent (wt %) with toluene diisocyanate (TDI)-terminated polyester prepolymer in an amount of about 40-20 weight percent (wt %), in the presence of an effective amount of surfactant, wherein the weight percent is based on the total weight of the prepolymers;
- (b) frothing the reaction mixture of step (a) by introducing a foaming agent into the reaction mixture;
- and
- (c) polymerizing the frothed reaction mixture in the presence of an effective amount of curative to form a polishing pad having a density ranging from about 0.6 to about 0.95 g/cc.
Dependencies are inferred from the claim text.