Method for slicing wafers from a workpiece using a sawing wire
View Patent ↗A method for slicing wafers from a workpiece using a sawing wire, wherein at least two wire guide rolls clamp a wire web, each wire guide roll having a multiplicity of grooves in its lateral surface, wherein at least one groove in which no wire is inserted during the wire sawing is present alongside a wire-guiding groove and, after wear on the wire-guiding grooves or after a defined number of sawing processes, the sawing wire is wound over into the previously unoccupied grooves that are not yet worn or used, respectively.
1. A method for slicing a wafer from a workpiece using a sawing wire, the method comprising:
forming a wire web with the sawing wire, the wire web comprising a multiplicity of wire sections arranged parallel, and the wire web being clamped at least by two wire guide rolls, a wire inlet side roll and a wire outlet side roll; and
guiding the sawing wire by the at least two wire guide rolls through wire-guiding grooves, the wire-guiding grooves having a distance A between each another, in two lateral surfaces, an each groove having a width C,
wherein at least one further groove, in which no wire is inserted during the wire sawing, is present alongside a wire-guiding groove, and
wherein the width C of the wire-guiding grooves and the further groove decreases from the wire inlet side roll to the wire outlet side roll.
2. The method of claim 1 , wherein the distance A between two wire-guiding grooves is constant over an entire length of the wire guide roll.
3. The method of claim 1 , wherein the distance A between two wire-guiding grooves decreases from a wire inlet side to a wire outlet side.
4. The method of claim 1 , further comprising:
winding the sawing wire over into a closest adjacent groove not yet guiding a sawing wire, once the wire-guiding grooves are worn.
5. The method of claim 1 , further comprising:
periodically winding the sawing wire over into a closest adjacent groove not yet guiding a sawing wire, once the wire-guiding grooves are used for a first defined number of sawing processes; and
winding the sawing wire back into previously used wire-guiding grooves, after a second defined number of sawing processes.
6. The method of claim 1 , wherein wire guide roll comprises a polyurethane comprising a polyester.
7. The method of claim 1 , wherein wire guide roll comprises a polyurethane comprising a polyether.
8. The method of claim 1 , wherein a depth T of the wire-guiding grooves is in a range of from 50 to 1500 μm.
9. The method of claim 1 , further comprising:
introducing the wire-guiding grooves for subsequent wire guidance into a casing of the wire guide rolls mechanically.
10. The method of claim 1 , further comprising:
introducing the wire-guiding grooves for subsequent wire guidance into a casing of the wire guide rolls optically.
11. The method of claim 1 , further comprising:
introducing the wire-guiding grooves for subsequent wire guidance into a casing of the wire guide rolls using a laser.
12. The method of claim 1 , wherein every n-th groove is occupied by a wire, n being at least two.
13. The method of claim 1 , wherein every second groove is occupied by a wire.
14. The method of claim 1 , wherein every third groove is occupied by a wire.
15. The method of claim 1 , wherein the grooves have identical depth.
16. The method of claim 1 , wherein the distance A between two wire-guiding grooves decreases from a wire inlet side to a wire outlet side, and
wherein the distance decreases in a range of from above 0 to 750 μm.
17. The method of claim 1 , wherein the wire guide roll includes (i) a core including a first material, and (ii) a casing including a second material.
18. The method of claim 17 , wherein the first material is identical to the second material.
19. The method of claim 17 , wherein the first material is different than the second material.
20. The method of claim 17 , wherein the casing has a thickness in a range of from 0.5 to 50 mm.