Annular grindstone

Patent metadata

Field	Value
Publication number	US-11229986-B2
Application number	US-201916360681-A
Country	US
Kind code	B2
Filing date	Mar 21, 2019
Priority date	Mar 29, 2018
Publication date	Jan 25, 2022
Grant date	Jan 25, 2022

Abstract

An annular grindstone includes a grindstone portion including a binding material, and abrasive grains which are dispersed into the binding material to be fixed, in which the binding material contains a nickel-iron alloy. Preferably, a contained ratio of iron in the nickel-iron alloy is in a range of 5 wt % or more to less than 60 wt %. More preferably, a contained ratio of iron in the nickel-iron alloy is in a range of 20 wt % or more to 50 wt % or less. Preferably, the annular grindstone includes the grindstone portion only. In addition, the annular grindstone further includes an annular base including a grip portion, in which the grindstone portion is exposed at an outer peripheral edge of the annular base.

First claim

What is claimed is:

1. an annular grindstone comprising: a grindstone portion including a binding material, and abrasive grains which are dispersed into the binding material to be fixed by electrodeposition to the grindstone,
wherein the binding material contains a nickel-iron alloy;
wherein a contained ratio of iron in the nickel-iron alloy is in a range of 20 wt % or more to 50 wt % or less.

2. The annular grindstone according to claim 1 ,
wherein the annular grindstone comprises the grindstone portion only.

3. The annular grindstone according to claim 1 , further comprising:
an annular base including a grip portion,
wherein the grindstone portion is exposed at an outer peripheral edge of the annular base.

4. The annular grindstone according to claim 1 , wherein the corrosion rate of the grindstone portion is 0% when cutting water comprising carbon dioxide is supplied to the grindstone.

5. A process for cutting a semiconductor wafer using an annular grindstone and cutting water, the grindstone comprising:
a grindstone portion including a binding material, and abrasive grains which are dispersed into the binding material to be fixed by electrodeposition to the grindstone,
wherein the binding material contains a nickel-iron alloy;
wherein a contained ratio of iron in the nickel-iron alloy is in a range of 20 wt % or more to 50 wt % or less;
the process comprising:
bringing the grindstone into contact with the semiconductor wafer; supplying the cutter water to the grindstone, wherein the cutter water comprises carbon dioxide.

6. The process of claim 5 wherein the cutting water has a specific resistance value of 0.1 MΩ·cm.

7. The process of claim 5 wherein the cutting water has a specific resistance value of 0.2 MΩ·cm.

8. The process of claim 5 , wherein the corrosion rate of the grindstone portion is 0% in response to the supplying the cutting water comprising carbon dioxide to the grindstone.

Assignees

• Disco Corp

Inventors

• Aikawa Hiroki

Classifications

• B24B27/0683 Primary

  Accessories therefor · CPC title

• B24D3/06 Primary

  metallic {or mixture of metals with ceramic materials, e.g. hard metals, "cermets", cements} · CPC title

• B24B41/04

  Headstocks; Working-spindles; Features relating thereto · CPC title

• B26D2001/0053

  having a special cutting edge section or blade section · CPC title

• B26D1/0006

  Cutting members therefor · CPC title