Method and apparatus for rounding the edges of semiconductive wafers

• US 4,718,202 A
• Filed: 08/23/1982
• Issued: 01/12/1988
• Est. Priority Date: 01/31/1980
• Status: Expired due to Fees

• Current Assignee: Pacific Western Systems, Inc.
• Original Assignee: Pacific Western Systems, Inc.
• Inventors: Worsham, Daniel A.
• Primary Examiner(s): OLSZEWSKI, ROBERT PAUL
• Application Number:
  US06/410,812
• Time in Patent Office: 1,968 Days
• Field of Search: 51/71, 51/74 R, 51/77 R, 51/103 R, 51/104, 51/215 AR, 51/215 R, 51/263, 51/283 R, 51/289 R, 51/289 S, 51/290, 51/292, 51/318, 409/132, 409/138, 198/625, 198/663
• US Class Current: 451/44
• CPC Class Codes: B24B 9/065 of thin, brittle parts, e.g. semiconductors, wafers

Abstract

In an apparatus for rounding the edges of semiconductive wafers, the wafers are loaded onto two parallel counter rotating screws one having a right hand thread and the other having a left hand thread. The grooves of respective ones of said screw engage the edges of the semiconductive wafer to be rounded. The grooves of the respective screws are of rounded cross-section and an abrasive slurry is introduced into the grooves to facilitate abrading of the edges of the wafers. A pressure roller engages the edges of the wafers and forces the wafers into the grooves to further facilitate rounding of the edges. Due to the action of the screws, the wafers, as they are being rounded are caused to traverse the length of the screws to provide a continuous processing of the wafers.

Claims

1. In a method for rounding the edges of semiconductive wafers, the steps of:

loading the wafers onto a screw so that the edges of the wafers to be rounded ride in a groove of said screw; and

turning said screw relative to said loaded wafers so as to rotate the wafer and to substantially abrade the edges of the loaded rotating wafers causing same to be rounded.

2. The method of claim 1 wherein said groove in said screw is of rounded cross section so as to cause the rounded edges of said loaded wafers to conform to the rounded contour of said groove.

3. The method of claim 1 including the step of applying a force to the loaded wafers to force their edges into frictional engagement with the walls of said groove in said screw.

4. In a method for rounding the edges of semiconductive wafers, the steps of:

loading the wafers onto a screw so that the edges of the wafers to be rounded ride in a groove of said screw;

turning said screw relative to said loaded wafers so as to rotate the wafer and to substantially abrade the edges of the loaded wafers causing same to be rounded; and

introducing an abrasive slurry into the groove of said screw to facilitate abrasion of the edges of the loaded wafers to be rounded.

5. In an apparatus for rounding the edges of semiconductive wafers:

screw means having threads dimensioned to receive the marginal edge of essentially only individual ones of the wafers to be ground and which are free to rotate;

means for turning said screw means relative to said wafer so as to rotate said wafer about an axis of rectilinear translation of the wafer and to substantially abrade the edges of the loaded wafers causing same to be rounded;

said screw means including a pair of generally parallel rotating screw means of left and right handed threads respectively;

means for counter rotating said screw means so as to cause the loaded wafers to travel axially of said rotating screw means along said axis of rectilinear translation to facilitate batch processing of semiconductive wafers to be rounded; and

means for introducing an abrasive slurry into said thread of said screw means to facilitate abrasion of the edges of the loaded wafers.

6. In an apparatus for rounding the edges of semiconductive wafers;

screw means having a thread groove to receive the marginal edges of the wafers to be rounded;

means for turning said screw means relative to said wafer so as to rotate the wafer about an axis parallel to the axis of revolution of said screw means to produce frictional engagement between said thread groove and the peripheral edge of the wafer for driving said wafer in opposite rotational senses at spaced peripheral portions of the wafer to substantially abrade the edges of the loaded wafers causing same to be rounded;

said screw means including a pair of generally parallel rotating screw means;

said screw means having said thread groove arranged so as to cause the wafer to travel axially of said rotating screw means to facilitate batch processing of semiconductive wafers to be ground; and

pressure roller means having an axis of rotation generally parallel to that of said screw means for engaging the edges of the loaded wafers for forcing the edges of the loaded wafers into frictional engagement with the walls of said groove in said screw means.

7. In an apparatus for rounding the edges of semiconductive wafers:

screw means having threads dimensioned to receive the marginal edges of essentially only individual ones of the wafers to be ground and which are free to rotate.

means for turning said screw means relative to said wafer so as to rotate said wafer about an axis of rectilinear translation and to substantially abrade the edges of the loaded wafers causing same to be rounded;

said screw meaens including a pair of generally parallel rotating screw means of left and right handed threads respectively; and

means for counter rotating said screw means so as to cause the loaded wafers to travel axially of said rotating screw means to facilitate batch processing of semiconductive wafers to be rounded.

8. The apparatus of claim 7 wherein said thread in said screw means is of a rounded cross section so as to cause the rounded edges of said loaded wafers to conform to the rounded contour of said thread.

9. The apparatus of claim 7 including means for applying a force to the loaded wafers to force the edges of the loaded wafers into frictional engagement with the walls of said thread in said screw means.