Polishing pad and method for making the same

Abstract

The present invention relates to a polishing pad and method for making the same. In the invention, a liquid-state polymer material is directly formed on the surface of a base material, and then the liquid-state polymer material is solidified to form a flat grinding layer. Whereby, the polishing pad has high unity and flatness. The grinding layer has attenuated structures and a plurality of holes, thus increasing the storage ability of polishing particles distributed in a polishing liquid. In addition, the polishing pad has high compression ratio, so the polishing pad can compactly contact a polishing workpiece, and will not scratch the surface of the polishing workpiece scratched. Therefore, the polishing effect and quality will be improved.

1 . A polishing pad, comprising:
 a base material, formed by covering a fiber layer with a polymer, and having a surface; and   a grinding layer, bonded to the surface, and having a plurality of holes.   
     
     
         2 . The polishing pad according to  claim 1 , wherein the fiber layer is made of a cloth material. 
     
     
         3 . The polishing pad according to  claim 2 , wherein the cloth material is a non-woven cloth. 
     
     
         4 . The polishing pad according to  claim 1 , wherein the material of the fiber layer is selected from PP, PET, or nylon. 
     
     
         5 . The polishing pad according to  claim 1 , wherein the polymer is continuous foam. 
     
     
         6 . The polishing pad according to  claim 5 , wherein the polymer is  15  selected from PU, PP, PET, or polymer resin. 
     
     
         7 . The polishing pad according to  claim 1 , wherein the surface is flattened, and the grinding layer is made of one material selected from PU, PP, PET, or polymer resin. 
     
     
         8 . The polishing pad according to  claim 1 , wherein the distribution thickness of the holes is at least half of a total thickness of the grinding layer. 
     
     
         9 . The polishing pad according to  claim 1 , wherein some fibers in the fiber layer are exposed on the surface, and are further covered by the grinding layer. 
     
     
         10 . The polishing pad according to  claim 1 , wherein the compression ratio of the polishing pad is 5% to 50%. 
     
     
         11 . The polishing pad according to  claim 1 , wherein the recovery ratio of the polishing pad is greater than 80%. 
     
     
         12 . The polishing pad according to  claim 1 , wherein a thickness of the polishing pad is 0.5 to 3.0 mm. 
     
     
         13 . The polishing pad according to  claim 1 , wherein the density of the polishing pad is 0.2 to 0.6 g/cm 3 . 
     
     
         14 . A method for making a polishing pad, comprising:
 (a) providing a base material, wherein the base material is formed by covering a fiber layer with a polymer and has a surface;   (b) forming a liquid-state polymer material on the surface; and   (c) solidifying the liquid-state polymer material to form a grinding layer, wherein the grinding layer is bonded to the surface and has a plurality of holes.   
     
     
         15 . The making method according to  claim 14 , wherein Step (a) further comprises:
 (a1) providing a fiber substrate;   (a2) immersing the fiber substrate in a polymer solution, so that the polymer solution covers the fiber substrate; and   (a3) solidifying the polymer solution to form the base material.   
     
     
         16 . The making method according to  claim 14 , wherein in Step (b), the liquid-state polymer material is formed on the surface by coating. 
     
     
         17 . The making method according to  claim 16 , wherein after Step (b), the liquid-state polymer material is solidified to form a flat surface, and the flat surface contacts a liquid-state polymer material in a coagulating tank, so as to form the grinding layer through single surface exchange. 
     
     
         18 . The making method according to  claim 14 , wherein in Step (c), the liquid-state polymer material is solidified by natural drying. 
     
     
         19 . The making method according to  claim 14 , wherein in Step (c), the liquid-state polymer material is solidified by air drying.