Water-soluble working fluid for fixed abrasive wire saw

Abstract

Provided is a water-soluble working fluid for a fixed-abrasive wire saw, the water-soluble working fluid comprising: (C) a carboxylic acid; (D) a compound which shows basicity on dissolution in water; and (E) water, wherein an electrical conductivity at 25°C of the water-soluble working fluid is 300 µS / cm or more and 3000 µS / cm or less; a pH at 25°C of the water-soluble working fluid is 5 or more and 10 or less; and a viscosity of a simulated fluid formed by adding 10 mass % of a silicon powder having an average particle size of 1.5 µm to the water-soluble working fluid and stirring a resultant mixture is less than 30 mPa·s at 25°C.

Description

technical field [0001] The present invention relates to water-soluble working fluids for fixed abrasive wire saws. Background technique [0002] In recent years, in order to reduce the manufacturing cost of semiconductor devices, the diameter of silicon wafers has been rapidly increased, and it has become important to improve the dicing and processing technology of silicon wafers. As this dicing processing technique, there is, for example, a dicing method using a wire tool (wire saw) with less cutting loss and high processing efficiency. There are free abrasive method and fixed abrasive method in the cutting method using the wire saw. The following problems have been pointed out in the free abrasive method: (1) Since the slurry obtained by dispersing the abrasive in the oil is used as the processing fluid, the The pollution of cutting operation and surrounding environment is significant; (2) it is necessary to discard the slurry containing a large amount of cutting chips ge...

AI Technical Summary

Problems solved by technology

There are free abrasive method and fixed abrasive method in the cutting method using the wire saw. The following problems have been pointed out in the free abrasive method: (1) Since the slurry obtained by dispersing the abrasive in the oil is used as the processing fluid, the The cutting operation and the pollution of the surrounding environment are significant; (2) It is necessary to discard the slurry containing a large amount of chips generated during cutting; (3) It is difficult to separate free abrasives and chips; (4) The speed of lead wire movement is limited, and the improvement of processing efficiency is limited, etc.

The non-aqueous processing fluid that basically does not contain water has the following problems: the non-aqueous volatile component (solvent component) deteriorates the working environment, the processing fluid becomes a flammable liquid, and the cleaning process after processing, waste liquid treatment, etc. become more soluble than those using water. The situation of sexual processing fluid is more complicated, etc.

That is, silicon has high reactivity. During cutting, it will react with moisture or alkali in the processing fluid to generate hydrogen gas, which may be flammable.

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