Dual-side wafer bar grinding

Abstract

A dual-side wafer bar grinding method and apparatus is disclosed herein that slices wafer bars from a wafer block for use in manufacturing thin film magnetic heads, for example. By grinding opposing faces of the wafer bars sliced from the wafer block, variations in flatness, perpendicularity, surface finish, and/or overall dimensions are improved.

What is claimed is: 
     
         1 . A method comprising:
 grinding opposing faces of a wafer bar sliced from a thin film wafer block.   
     
     
         2 . The method of  claim 1 , further comprising:
 slicing the wafer bar from the wafer block.   
     
     
         3 . The method of  claim 2 , wherein the grinding operation includes:
 grinding a first surface of the wafer block prior to the slicing operation; and   grinding a second surface of the wafer bar after to the slicing operation, wherein the first surface and the second surface are the opposing faces.   
     
     
         4 . The method of  claim 1 , wherein the grinding operation is accomplished using opposite sides of a grinding wheel. 
     
     
         5 . The method of  claim 4 , wherein the grinding wheel has an area of increased thickness that performs the grinding operation. 
     
     
         6 . The method of  claim 5 , wherein the area of increased thickness has one of a curved cutting surface and a faceted cutting surface. 
     
     
         7 . The method of  claim 1 , wherein the grinding operation simultaneously grinds a face of the wafer block and a face of the wafer bar. 
     
     
         8 . The method of  claim 1 , wherein the grinding operation sequentially grinds a face of the wafer block and a face of the wafer bar. 
     
     
         9 . The method of  claim 1 , wherein the wafer bar includes a row of thin film heads. 
     
     
         10 . The method of  claim 1 , wherein the wafer bar is less than 200 μm thick. 
     
     
         11 . An apparatus comprising:
 a slicing blade mounted on an axle that slices wafer bars from a thin film wafer block; and   a grinding wheel mounted on the axle that grinds opposing faces of the wafer bar.   
     
     
         12 . The apparatus of  claim 11 , wherein the grinding wheel is configured to grind a first surface of the wafer block prior to the slicing operation and grind a second surface of the wafer bar after to the slicing operation, wherein the first surface and the second surface are the opposing faces. 
     
     
         13 . The apparatus of  claim 11 , wherein the grinding wheel is configured to grind the opposing faces of the wafer bar using opposite sides of a grinding wheel. 
     
     
         14 . The apparatus of  claim 11 , wherein the grinding wheel has an area of increased thickness that performs the grinding operation. 
     
     
         15 . The apparatus of  claim 14 , wherein the area of increased thickness has one of a curved cutting surface and a faceted cutting surface. 
     
     
         16 . The apparatus of  claim 11 , wherein the grinding wheel is configured to simultaneously grind a face of the wafer block and a face of the wafer bar. 
     
     
         17 . The apparatus of  claim 11 , wherein the grinding wheel is configured to sequentially grind a face of the wafer block and a face of the wafer bar. 
     
     
         18 . The apparatus of  claim 11 , wherein the wafer bar includes a row of thin film heads. 
     
     
         19 . The apparatus of  claim 11 , wherein the wafer bar is less than 200 μm thick. 
     
     
         20 . A bar of thin film heads sliced from a block of substrate material, wherein the bar of thin film heads has mechanically ground opposing faces.