Single crystal silicon wire cutting debris cleaning method

Abstract

A method for cleaning debris in monocrystal silicon wire-cut electrical discharge machining relates to solar silicon washing techniques and comprises the following sequential steps: a, charging debris into a cleaning basket of pp, and soaking in HF (hydrofluoric acid); b, adding KOH into a cleaning tank, placing the basket holding the debris from monocrystal silicon wire-cut electrical discharge machining into an alkaline solution, stirring and cleaning with a polytetrafluoroethylene rod, and rinsing with purified water; c, preparing mixed liquid with HCL, HF and purified water, placing the basket holding the debris from monocrystal silicon wire-cut electrical discharge machining into the mixed liquid, stirring, cleaning and rinsing; d, adding purified water, heating to 40-50 DEG C, ultrasonically cleaning, transferring to a cleaning liquid, drying to obtain circulation tailing meeting the standard for ingot casting. The method has the advantages that for the debris from monocrystal silicon wire-cut electrical discharge machining, cutting waste liquid residue and metal impurity produced during cutting procedure are thoroughly removed by blending different chemical reagents via multiple cleaning, quality level of monocrystal debris is increased, ingot production cost is reduced, and feedable quantity of fragmented silicon is increased so that cost reduction and efficiency increasing are achieved.

Description

technical field [0001] The invention relates to the technical field of solar mono- and polycrystalline silicon wafer manufacturing, in particular to the technology of single-crystalline silicon wire cutting debris washing. Background technique [0002] As the price of raw polycrystalline polysilicon ingots continues to decline, the cost of waste treatment such as wire cutting chips is relatively high; at present, the market is generally HF+HNO3 mixed solution pickling treatment or traditional alkaline cleaning treatment, and the cost of pickling treatment is relatively high. The cost of chemical reagents per kilogram of waste in production and treatment is about 5 yuan, and the pressure on environmental protection is high. Although the cost of traditional alkaline cleaning treatment is low, the loss of silicon wafers is not easy to control. With the promotion of diamond wire cutting technology in the field of single crystal, the single crystal market is bound to pick up; the...

AI Technical Summary

Problems solved by technology

[0004] The object of the present invention is to provide a method for cleaning and treating monocrystalline silicon wire cutting fragments, which overcomes the defects of the existing processing technology, and has low processing cost and is suitable for the next process of casting ingots and putting them into furnaces.