Grind wheel design for low edge-roll grinding

Patent metadata

Field	Value
Publication number	US-12533767-B2
Application number	US-202418598825-A
Country	US
Kind code	B2
Filing date	Mar 7, 2024
Priority date	Mar 7, 2024
Publication date	Jan 27, 2026
Grant date	Jan 27, 2026

Abstract

Grinding systems and methods for semiconductor workpieces are provided. In one example, a grinding system includes a workpiece support operable to support a semiconductor workpiece and rotate the semiconductor workpiece about a first axis. The grinding system further includes a grind wheel operable to rotate about a second axis. The grind wheel has a plurality of grinding teeth arranged in a grinding ring on the grind wheel. A radius of the grinding ring is less than or equal to a radius of the semiconductor workpiece (e.g., such that an effective gap ratio between grinding teeth on the grind wheel are reduced).

First claim

What is claimed is:

1 . A grinding system for a semiconductor workpiece, the grinding system comprising:
a workpiece support operable to support a semiconductor workpiece and rotate the semiconductor workpiece about a first axis; and a grind wheel operable to rotate about a second axis, wherein the grind wheel has a plurality of first grinding teeth arranged in a first grinding ring on the grind wheel; wherein a radius of the first grinding ring is such that grind wheel comprises an effective gap ratio when the plurality of first grinding teeth are contacting an edge of the semiconductor workpiece of about 0.8 or less, wherein the effective gap ratio comprises a ratio of an effective gap measurement between the plurality of first grinding teeth to an actual gap measurement between the plurality of first grinding teeth, wherein the effective gap measurement is a distance between a last point of a grinding tooth of the plurality of first grinding teeth contacting an edge of the semiconductor workpiece and a first point of an adjacent grinding tooth of the plurality of first grinding teeth contacting the edge of the semiconductor workpiece in a rotational direction of the grind wheel.

2 . The grinding system of claim 1 , wherein the grind wheel is positioned such that the first grinding ring at least partially overlaps a center of the workpiece support.

3 . The grinding system of claim 1 , wherein each of the plurality of first grinding teeth comprises a grind surface, the grind surface having a first edge and a second edge forming an acute angle.

4 . The grinding system of claim 3 , wherein the acute angle is in a range of 1° to 60°.

5 . The grinding system of claim 3 , wherein the grind surface has a parallelogram shape.

6 . The grinding system of claim 1 , wherein the grind wheel comprises a second grinding ring that is arranged within the first grinding ring, the second grinding ring comprising a plurality of second grinding teeth.

7 . The grinding system of claim 6 , wherein the plurality of first grinding teeth of the first grinding ring are staggered relative to the plurality of second grinding teeth of the second grinding ring.

8 . The grinding system of claim 1 , wherein each of the plurality of first grinding teeth comprise an abrasive containing material.

9 . The grinding system of claim 1 , wherein the semiconductor workpiece comprises silicon carbide.

10 . The grinding system of claim 1 , wherein the radius of the first grinding ring is such that the effective gap ratio when the plurality of first grinding teeth are contacting the edge of the semiconductor workpiece is about 0.5 or less.

11 . The grinding system of claim 1 , wherein the radius of the first grinding ring is such that the effective gap ratio when the plurality of first grinding teeth are contacting the edge of the semiconductor workpiece is about 0.1 or less.

12 . A method for grinding a surface of a semiconductor workpiece, comprising:
providing a semiconductor workpiece on a workpiece support, the workpiece support rotatable about a first axis; providing a surface of the semiconductor workpiece against a first grinding ring on a grind wheel, the grind wheel rotatable about a second axis; and rotating one or more of the grind wheel or the workpiece support to implement a grinding operation on the semiconductor workpiece; wherein an effective gap ratio when a plurality of grinding teeth are contacting an edge of the semiconductor workpiece is about 0.8 or less, wherein the effective gap ratio comprises a ratio of an effective gap measurement between the plurality of grinding teeth to an actual gap measurement between the plurality of grinding teeth, wherein the effective gap measurement is a distance between a last point of a grinding tooth of the plurality of grinding teeth contacting an edge of the semiconductor workpiece and a first point of an adjacent grinding tooth of the plurality of grinding teeth contacting the edge of the semiconductor workpiece in a rotational direction of the grind wheel.

13 . The method of claim 12 , wherein a radius of the first grinding ring is less than a radius of the semiconductor workpiece.

14 . The method of claim 12 , wherein each of the plurality of grinding teeth comprises a grind surface, the grind surface having a first edge and a second edge forming an acute angle.

15 . The method of claim 12 , wherein the grind wheel comprises a second grinding ring that is arranged within the first grinding ring, the second grinding ring comprising a plurality of second grinding teeth.

16 . The method of claim 12 , wherein each of the plurality of grinding teeth comprise an abrasive containing material.

17 . The method of claim 12 , wherein the semiconductor workpiece comprises silicon carbide.

18 . The method of claim 12 , wherein the effective gap ratio when the plurality of grinding teeth are contacting the edge of the semiconductor workpiece is about 0.5 or less.

19 . The method of claim 12 , wherein the effective gap ratio when the plurality of grinding teeth are contacting the edge of the semiconductor workpiece is about 0.1 or less.

Assignees

• Wolfspeed Inc

Inventors

• Bubel Simon
• Leonard Robert

Classifications

• H01L21/0445

  Electricity · mapped topic

• B24B37/16

  characterised by the shape of the lapping plate surface, e.g. grooved · CPC title

• B24B7/228 Primary

  for grinding thin, brittle parts, e.g. semiconductors, wafers (grinding edges of thin, brittle parts B24B9/065) · CPC title

• H10D62/8325

  Silicon carbide · CPC title

• B24D7/14

  Zonally-graded wheels; Composite wheels comprising different abrasives · CPC title