US 11,717,930 B2
Method for simultaneously cutting a plurality of disks from a workpiece
Guenther Grupp Mueller, Portland, OR (US); James Mal, Portland, OR (US); Adam Marion, Beaverton, OR (US); Stan Meek, Portland, OR (US); and James Mullins, Hillsboro, OR (US)
Assigned to SILTRONIC CORPORATION, Portland, OR (US)
Filed by Siltronic Corporation, Portland, OR (US)
Filed on May 31, 2021, as Appl. No. 17/334,829.
Prior Publication US 2022/0379426 A1, Dec. 1, 2022
Int. Cl. B24B 27/06 (2006.01); B24B 51/00 (2006.01); B24B 55/02 (2006.01)
CPC B24B 27/0633 (2013.01) [B24B 51/00 (2013.01); B24B 55/02 (2013.01)] 12 Claims
OG exemplary drawing
 
1. A method of cutting semiconductor wafers, the method comprising:
providing a semiconductor ingot in the shape of a cylinder;
cutting the semiconductor ingot into a workpiece using a saw; and
sawing the workpiece into slices using a wire grid comprising a fixed abrasive grain wire guided around two rollers, the rollers having grooves in which the fixed abrasive grain wire is guided,
wherein during the sawing, the workpiece is moved towards the wire grid,
wherein at a first contact of the workpiece with the wire grid, an initial cutting speed vstart is less than 2 mm/min, at the same time a coolant flow is less than 0.1 l/h, and at the same time a speed of the fixed abrasive grain wire vw is greater than 20 m/s,
wherein after the first contact, the workpiece is guided through the wire grid until a first cutting depth of at least 7 mm is reached,
wherein, during the sawing, the coolant flow remains constant until the first cutting depth is reached, and is then increased to at least 2000 l/h, and
wherein the cutting speed is reduced to less than 70% of the initial cutting speed between the first contact of the workpiece with the wire grid up to a cutting depth of half a diameter of the cylinder and is then increased.