Polishing pad having a sealed pressure relief channel

Abstract

The present invention provides a chemical mechanical polishing pad comprising a window formed in the polishing pad, the window having a void provided on a side thereof. The invention further provides a pressure relief channel provided in the polishing pad from the void to a periphery of the polishing pad. In addition, a membrane is provided in the channel to prevent contamination of the void.

1 . A chemical mechanical polishing pad comprising: 
 a window formed in the polishing pad, the window having a void provided on a side thereof;    a pressure relief channel provided in the polishing pad from the void to a periphery of the polishing pad; and    a membrane provided in the channel to prevent contamination of the void.    
     
     
         2 . The polishing pad of  claim 1  wherein the membrane is selected from the group comprising polyester, polyethylene, polypropylene, fluoropolymers, polyurethane foamed films, silicone, nylon, silk, woven materials and polyethylene terephthalate.  
     
     
         3 . The polishing pad of  claim 2  wherein the membrane is polytetrafluoroethylene.  
     
     
         4 . The polishing pad of  claim 3  wherein the membrane is expanded polytetrafluoroethylene.  
     
     
         5 . The polishing pad of  claim 1  wherein the pressure relief channel has a width between 0.70 mm to 6.50 mm.  
     
     
         6 . The polishing pad of  claim 5  wherein the width varies between the void to the periphery of the polishing pad.  
     
     
         7 . The polishing pad of  claim 1  wherein the pressure relief channel has a depth between 0.38 mm to 1.53 mm.  
     
     
         8 . A chemical mechanical polishing pad comprising: 
 a polishing layer having a window formed therein, the window being exposed to a void on a side thereof;    a pressure relief channel provided in the polishing layer from a portion of the void-exposed side of the window to a periphery of the polishing layer; and    a membrane provided in the channel to prevent contamination of the void.    
     
     
         9 . A chemical mechanical polishing pad comprising: 
 a polishing layer overlying a bottom layer, and an adhesive layer disposed between the polishing layer and the bottom layer;    a window formed in the polishing layer, the window being exposed to a void on a side thereof;    a pressure relief channel provided in the adhesive layer from the void to a periphery of the adhesive layer; and    a membrane provided in the channel to prevent contamination of the void.    
     
     
         10 . A chemical mechanical polishing pad comprising: 
 a polishing layer overlying a bottom layer, and an adhesive layer disposed between the polishing layer and the bottom layer;    a window formed in the polishing layer, the window being exposed to a void on a side thereof;    a pressure relief channel provided in the bottom layer from the void to a periphery of the bottom layer; and    a membrane provided in the channel to prevent contamination of the void.