Method for slicing workpiece and processing liquid

Patent metadata

Field	Value
Publication number	US-10189181-B2
Application number	US-201515124245-A
Country	US
Kind code	B2
Filing date	Mar 6, 2015
Priority date	Apr 3, 2014
Publication date	Jan 29, 2019
Grant date	Jan 29, 2019

Abstract

The present invention is a method for slicing a workpiece, including: forming a wire row by a wire spirally wound between a plurality of wire guides and traveling in an axial direction, and pressing a workpiece against the wire row while supplying a processing liquid containing abrasive grains to a contact portion between the workpiece and the wire, wherein a used portion of the abrasive grains are subjected to a treatment with a mixed liquid of sulfuric acid and hydrogen peroxide, and the abrasive grains subjected to the treatment are reused for the slicing of a workpiece. This makes it possible to slice a workpiece with suppressing contamination of a wafer with metal impurities when abrasive grains are reused in slicing a workpiece by use of a wire saw.

First claim

The invention claimed is:

1. A method for slicing workpieces, comprising:
forming a wire row by a wire spirally wound between a plurality of wire guides and traveling in an axial direction,
pressing a workpiece against the wire row while supplying a processing liquid comprising abrasive grains to a contact portion between the workpiece and the wire to slice the workpiece and thereby producing a waste slurry comprising at least a portion of the abrasive grains,
recovering at least a portion of the abrasive grains from the waste slurry,
subjecting the recovered abrasive grains to a treatment with a mixed liquid of sulfuric acid and hydrogen peroxide,
dispersing the treated abrasive grains into coolant to make a reused processing liquid, and
reusing the treated abrasive grains in the reused processing liquid for slicing of another workpiece.

2. The method of claim 1 , wherein
a concentration of copper contained in the treated abrasive grains is 1 ppm or less per 1 g of the treated abrasive grains.

3. The method of claim 1 , wherein the subjecting the recovered abrasive grains to the treatment with the mixed liquid of sulfuric acid and hydrogen peroxide removes copper from the recovered abrasive grains.

Assignees

• Shinetsu Handotai Kk

Inventors

• Kanbayashi Keiichi

Classifications

• B28D5/045

  by cutting with wires or closed-loop blades (B28D5/042 takes precedence) · CPC title

• C09K3/1463

  Aqueous liquid suspensions · CPC title

• B28D5/007 Primary

  Use, recovery or regeneration of abrasive mediums (for grinding and polishing in general B24B57/00) · CPC title

• Y02P70/179

  Cross-Sectional Technologies · mapped topic

• B24B27/0633 Primary

  using a cutting wire · CPC title