Method of and apparatus for abrading outer peripheral parts of a semiconductor wafer

Abstract

The invention provides a method of and an apparatus for abrading outer peripheral parts of a semiconductor wafer having a protective sheet adhesively attached to its surface where semiconductor elements are formed. The semiconductor wafer is held horizontally and an abrading tape held inside an abrading head is run and pressed against the outer peripheral part of the semiconductor wafer. The abrading tape has abrading particles attached to a base sheet by electrostatic spraying.

1 . A method of abrading outer peripheral parts of a semiconductor wafer having a front surface on which semiconductor elements are formed and a protective sheet is adhesively attached, said method comprising the steps of:
 holding said semiconductor wafer such that said front surface is horizontal; and   causing an abrading tape mounted inside an abrading head to run and pressing said abrading tape against and thereby abrading an outer peripheral part of said semiconductor wafer;   wherein said abrading tape has abrading particles attached thereto by electrostatic spraying.   
   
   
       2 . The method of  claim 1  wherein said semiconductor wafer is held with said front surface facing downward and said outer peripheral part is abraded together with said protective sheet. 
   
   
       3 . The method of  claim 1  wherein said abrading tape runs horizontally or vertically while being pressed against said outer peripheral part of said semiconductor wafer. 
   
   
       4 . The method of  claim 1  wherein said abrading tape mounted inside said abrading head is pressed against and caused to abrade said semiconductor wafer, having a tape surface sloped by an angle of 10° or less from the vertical direction. 
   
   
       5 . The method of  claim 1  wherein said abrading particles are within the range of #600 or 30 μm to #3000 or 5 μm. 
   
   
       6 . The method of  claim 1  wherein a holding guide provided with a pad at a tip is mounted inside said abrading head and wherein a sliding motion of said holding guide causes said abrading tape to be pressed against and to thereby abrade said outer peripheral part of said semiconductor wafer. 
   
   
       7 . The method of  claim 6  wherein said pad comprises an elastic material having shore-A hardness in the range of 20-50°. 
   
   
       8 . The method of  claim 7  wherein said pad comprises a lubricant material at least on a frontal contact surface. 
   
   
       9 . An abrading apparatus for abrading outer peripheral parts of a semiconductor wafer having a front surface on which semiconductor elements are formed and a protective sheet is adhesively attached, said abrading apparatus comprising:
 holding means for holding said semiconductor wafer such that said front surface is horizontal; and   an abrading head containing therein an abrading tape which is adapted to run and to abrade an outer peripheral part of said semiconductor wafer being held by said holding means;   wherein said abrading tape has abrading particles attached thereto by electrostatic spraying.   
   
   
       10 . The abrading apparatus of  claim 9  wherein said abrading head is rotatable such that said abrading tape runs horizontally or vertically while being pressed against said outer peripheral part of said semiconductor wafer. 
   
   
       11 . The abrading apparatus of  claim 9  wherein said abrading head is rotatable such that said abrading tape is pressed against and caused to abrade said semiconductor wafer, having a tape surface sloped by an angle of 10° or less from the vertical direction while running. 
   
   
       12 . The abrading apparatus of  claim 9  wherein said abrading particles are within the range of #600 or 30 μm to #3000 or 5 μm. 
   
   
       13 . The abrading apparatus of  claim 9  wherein a holding guide provided with a pad at a tip is mounted inside said abrading head and wherein a sliding motion of said holding guide causes said abrading tape to be pressed against and to thereby abrade said outer peripheral part of said semiconductor wafer. 
   
   
       14 . The abrading apparatus of  claim 13  wherein said pad comprises an elastic material having shore-A hardness in the range of 20-50°. 
   
   
       15 . The abrading apparatus of  claim 14  wherein said pad comprises a lubricant material at least on a frontal contact surface. 
   
   
       16 . The abrading apparatus of  claim 13  wherein said abrading head further comprises a pressing position adjusting mechanism that rotates said holding guide in a radial direction of said semiconductor wafer;
 wherein said pressing position adjusting mechanism comprises a rotary arm that undergoes a rotary motion with said holding guide mounted thereto, a shaft that is connected to said rotary arm and a driving device that is connected to and transmits a torque for said rotary motion to said shaft; and   wherein said abrading head serves to control said torque by said driving device to adjust the rotary position where said abrading tape is pressed by said holding guide onto said outer peripheral part of said semiconductor wafer.