Polishing pad of polymer coating

Abstract

A polishing pad constructed with an underlay providing a shaped preform, and a layer of polishing material provided as a coating conforming to the shaped preform, the coating forming a polishing surface on the polishing pad, the coating adhering to the shaped preform without completely covering openings extending through the thickness of the underlay, whereby the openings provide the polishing pad with a desired porosity.

What is claimed is:  
     
         1 . A polishing pad comprising: an underlay with openings extending through the thickness of the underlay, the underlay providing a shaped preform, and a layer of polishing material provided as a coating conforming to the shaped preform, the coating forming a polishing surface on the polishing pad, the coating adhering to the shaped preform without completely covering the openings extending through the thickness of the underlay, whereby the openings provide the polishing pad with a desired porosity.  
     
     
         2 . The polishing pad as recited in  claim 1 , further comprising: the openings providing passages for flowing polishing fluid.  
     
     
         3 . The polishing pad as recited in  claim 1 , further comprising: the openings being arranged in an array of openings, and the array of openings through the thickness of the underlay providing a porous filter.  
     
     
         4 . The polishing pad as recited in  claim 1 , further comprising: the shaped preform having a preform topography corresponding to a desired surface texture for the polishing pad, and the coating conforming to the preform topography to provide the polishing pad with the desired surface texture.  
     
     
         5 . The polishing pad as recited in  claim 1 , further comprising: the shaped preform having reinforcing strands.  
     
     
         6 . The polishing pad as recited in  claim 1 , further comprising: the shaped preform being a further polishing material under the coating of polishing material.  
     
     
         7 . The polishing pad as recited in  claim 1 , further comprising: the coating further having abrasive particles distributed in the polishing material.  
     
     
         8 . The polishing pad as recited in  claim 1 , further comprising: the underlay having multiple strands arranged in an array of strands, and the openings through the thickness of the underlay being provided by clearance spaces among the strands.  
     
     
         9 . The polishing pad as recited in  claim 1 , further comprising: the underlay having multiple strands arranged in an array of strands, the array of strands including one or more of; an randomly arranged array, a woven array, and a repeating pattern array, and the openings through the thickness of the underlay being provided by clearance spaces among the strands.  
     
     
         10 . The polishing pad as recited in  claim 1 , further comprising: the underlay having multiple strands arranged in an array of strands, the array of strands including, a woven array and a repeating pattern array, and the openings through the thickness of the underlay being provided by clearance spaces among the strands.  
     
     
         11 . A polishing pad comprising: an underlay providing a shaped preform, the shaped preform having a shaped preform topography corresponding to a desired surface texture for the polishing pad, and a layer of polishing material provided as a coating conforming to the shaped preform, the coating forming a polishing surface on the polishing pad, and the coating overlying the shaped preform topography to provide the polishing surface with a surface texture with minimized macro-defects.  
     
     
         12 . The polishing pad as recited in  claim 11 , further comprising: openings extending through a thickness of the underlay, the coating adhering to the underlay without covering the openings, and the openings providing the polishing pad with a desired porosity.  
     
     
         13 . The polishing pad as recited in  claim 11  wherein, the shaped preform comprises, multiple strands arranged in an array of strands, the shaped preform topography being shaped by sizes and shapes of the strands.  
     
     
         14 . The polishing pad as recited in  claim 1  wherein, the shaped preform comprises, multiple strands woven together, the polishing material comprises, a coating on each of the strands, and the coating on each of the strands being woven together with the strands.  
     
     
         15 . The polishing pad as recited in  claim 1  wherein, the shaped preform comprises, multiple strands woven together, the polishing material comprises, a coating on each of the strands, and the strands being woven together without the coating being woven together with the strands.  
     
     
         16 . A method for making a polishing pad, comprising the steps of: fabricating an underlay to provide a preform with a shaped preform topography corresponding to a desired surface texture for the polishing pad, overlying the underlay with a polishing material in a manner to provide a polishing surface on the polishing pad, and overlying the shaped preform topography with the polishing material to provide the polishing surface with a surface texture with minimized macro-defects.  
     
     
         17 . The method as recited in  claim 16 , further comprising: providing openings through the underlay to provide passages for flowing polishing fluid.  
     
     
         18 . The method as recited in  claim 16 , further comprising: providing openings through the underlay to provide passages of a porous filter.  
     
     
         19 . The method as recited in  claim 16 , further comprising: providing the underlay with reinforcing strands.  
     
     
         20 . The method as recited in  claim 16 , further comprising: providing the shaped preform as having a further polishing material under the coating of polishing material.  
     
     
         21 . The method as recited in  claim 16 , further comprising: providing the coating with abrasive particles distributed in the polishing material.  
     
     
         22 . The method as recited in  claim 16 , further comprising: providing the underlay as having multiple strands arranged in an array of strands, and providing openings through the thickness of the underlay as clearance spaces among the strands.  
     
     
         23 . The method as recited in  claim 16 , further comprising: providing the underlay as having multiple strands arranged in an array of strands, the array of strands including one or more of; an randomly arranged array, a woven array, and a repeating pattern array, and providing openings through the thickness of the underlay as clearance spaces among the strands.  
     
     
         24 . The method as recited in  claim 25 , further comprising: providing the underlay as having multiple strands arranged in an array of strands, the array of strands including, a woven array and a repeating pattern array, and providing openings through the thickness of the underlay as clearance spaces among the strands.  
     
     
         25 . A method for making a polishing pad, comprising the steps of: fabricating an underlay as a shaped preform with openings extending through the thickness of the underlay, coating the underlay with a layer of polishing material in a manner to conform the coating to the shaped preform and form a polishing surface on the polishing pad, and adhering the coating to the shaped preform without completely covering the openings extending through the thickness of the underlay to provide the polishing pad with a desired porosity.  
     
     
         26 . The method as recited in  claim 25 , further comprising: providing openings through the underlay to provide passages for flowing polishing fluid.  
     
     
         27 . The method as recited in  claim 25 , further comprising: providing openings through the underlay to provide passages of a porous filter.  
     
     
         28 . The method as recited in  claim 25 , further comprising: providing the shaped preform with a preform topography corresponding to a desired surface texture for the polishing pad, and conforming the coating to the preform topography to provide the polishing pad with the desired surface texture.  
     
     
         29 . The method as recited in  claim 25 , further comprising: providing the underlay with reinforcing strands.  
     
     
         30 . The method as recited in  claim 25 , further comprising: providing the shaped preform as having a further polishing material under the coating of polishing material.  
     
     
         31 . The method as recited in  claim 25 , further comprising: providing the coating with abrasive particles distributed in the polishing material.  
     
     
         32 . The method as recited in  claim 25 , further comprising: providing the underlay as having multiple strands arranged in an array of strands, and providing the openings through the thickness of the underlay as clearance spaces among the strands.  
     
     
         33 . The method as recited in  claim 25 , further comprising: providing the underlay as having multiple strands arranged in an array of strands, the array of strands including one or more of; an randomly arranged array, a woven array, and a repeating pattern array, and providing the openings through the thickness of the underlay as clearance spaces among the strands.  
     
     
         34 . The method as recited in  claim 25 , further comprising: providing the underlay as having multiple strands arranged in an array of strands, the array of strands including, a woven array and a repeating pattern array, and providing the openings through the thickness of the underlay as clearance spaces among the strands.