Method and apparatus for polishing the edge of a bonded wafer
AssigneeAccretech USA, Inc.
InventorRobert E. Steere, III
Life of this patent
Estimating the term…
Abstract
A polishing bar is provided with a plurality of backings that are carried via blocks of impact absorbent material on a bar of greater stiffness. Each backing is shaped with two surfaces at an angle to each other. A polishing tape is disposed over the angled surfaces of each backing. The portion of the polishing tape over the forward surface of the backing is employed to polish the angled edge of the top wafer of a rotating bonded wafer pair.
Claims16
An apparatus for polishing a bonded wafer, said apparatus comprising
- a support;
- a body of impact absorbent material mounted on said support;
- a backing mounted on said body and having a first surface and a second surface disposed at an angle to said first surface, said first and second surfaces being disposed on an opposite side of said backing from said body and said support;
- and
- means for positioning a polishing tape on said first surface and said second surface of said backing whereby said first surface is positioned for polishing a peripheral edge of a top wafer of a pair of bonded wafers.
In combination
- a support;
- a body of impact absorbent material mounted on said support;
- a backing mounted on said body and having a pair of surfaces disposed at an angle to each other and disposed on an opposite side of said backing from said body and said support;
- and
- a polishing tape on said surfaces of said backing for positioning of a portion of said tape on a forward surface of said surfaces against a peripheral edge of a top wafer of a pair of bonded wafers.
A method of polishing a bonded wafer, said method comprising the steps of
- rotating a pair of bonded wafers including a handling wafer and a top wafer bonded to the handling wafer about an axis perpendicular to the top wafer, the top wafer having a lesser diameter than the handling wafer and the handling wafer having an exposed ledge extending beyond the top wafer;
- positioning a backing having a first surface and a second surface disposed at an angle to said first surface opposite a peripheral edge of the top wafer;
- positioning a polishing tape on the first surface of the backing in facing relation to the peripheral edge of the top wafer;
- and
- moving the top wafer and backing relative to each other perpendicularly of said axis to bring the polishing tape into polishing contact with the peripheral edge of the rotating top wafer.
A method of processing a bonded wafer, said method comprising the steps of
- rotating a pair of bonded wafers including a handling wafer, a top wafer and a bonding layer bonding the top wafer to the handling wafer about an axis perpendicular to the top wafer, the top wafer having a lesser diameter than the handling wafer, the handling wafer having an exposed ledge extending beyond the top wafer and the bonding layer having an exposed periphersl edge;
- positioning a backing having a first surface and a second surface disposed at an angle to said first surface opposite a peripheral edge of the top wafer;
- positioning a polishing tape on the first surface of the backing in facing relation to the peripheral edge of the top wafer;
- and
- moving the top wafer and backing relative to each other perpendicularly of said axis to bring the polishing tape at the juncture of the first surface and second surface of the backing into contact with the peripheral edge of the bonding layer.
Dependencies are inferred from the claim text.