Workpiece polishing apparatus

Abstract

A workpiece polishing apparatus including a polishing pad to polish a workpiece, a polishing agent supplying mechanism to supply a polishing agent, and a polishing head to hold the workpiece such that a back surface of the workpiece is held by a backing pad and an edge of the workpiece is held by an annular template. This apparatus polishes the workpiece by pressing the workpiece and the template against the polishing pad and thereby bringing the workpiece into sliding contact with the polishing pad. The template is made of a resin containing filler or woven fabric and has fine depressions created by filler or woven fabric exposed on the surface on the side that presses the polishing pad. This apparatus can stabilize the polishing rate of the outer circumferential portion of the workpiece and thereby polish the workpiece into a very flat workpiece.

1 . A workpiece polishing apparatus comprising:
 a polishing pad configured to polish a workpiece;   a polishing agent supplying mechanism configured to supply a polishing agent; and   a polishing head including a backing pad and an annular template configured to hold the workpiece such that a back surface of the workpiece is held by the backing pad and an edge of the workpiece is held by the template;   the apparatus being configured to polish the workpiece by pressing the workpiece and the template against the polishing pad and thereby bringing the workpiece into sliding contact with the polishing pad, wherein   the template is made of a resin containing filler and has fine depressions on a surface on a side that presses the polishing pad, the fine depressions being created by the filler exposed on the surface on the side that presses the polishing pad, and   a surface coverage of the depressions on the surface of the template on the side that presses the polishing pad ranges from 5% to 85%.   
     
     
         2 . The workpiece polishing apparatus according to  claim 1 , wherein each of the depressions has a depth of 0.05 mm or more. 
     
     
         3 . The workpiece polishing apparatus according to  claim 1 , wherein each of the depressions has an opening with a width of 5 mm or less, and pitches among the depressions are 10 mm or less. 
     
     
         4 . The workpiece polishing apparatus according to  claim 2 , wherein each of the depressions has an opening with a width of 5 mm or less, and pitches among the depressions are 10 mm or less. 
     
     
         5 . The workpiece polishing apparatus according to  claim 1 , wherein a contact angle between each of the depressions and the polishing pad is 90° or less. 
     
     
         6 . The workpiece polishing apparatus according to  claim 2 , wherein a contact angle between each of the depressions and the polishing pad is 90° or less. 
     
     
         7 . The workpiece polishing apparatus according to  claim 3 , wherein a contact angle between each of the depressions and the polishing pad is 90° or less. 
     
     
         8 . The workpiece polishing apparatus according to  claim 4 , wherein a contact angle between each of the depressions and the polishing pad is 90° or less. 
     
     
         9 . The workpiece polishing apparatus according to  claim 1 , wherein the surface coverage of the depressions on the surface of the template on the side that presses the polishing pad is more than 25% and 85% or less.