Cyclic utilization method of solar silicon wafer texturing solution

Abstract

The present invention discloses a cyclic utilization method of solar silicon wafer texturing solution. The method comprises the following steps of: (1) performing etching processing of a solar siliconwafer by employing a texturing solution, employing a reverse osmosis membrance circulation separation device to separate fluosilicic acid impurities from the mixed solution after etching on an etching groove; (2) performing quantitative analysis of hydrofluoric acid and nitric acid in the mixed solution after separation of the impurities respectively by employing an automatic measurement potentiometric titrator and a nitrate ion selective electrode automatic measurement potentiostat to obtain component concentration increment or decrement of the mixed solution after etching; and (3) accordingto the component concentration increment or decrement, adding acid with decreased concentration into the etching process or the cyclic utilization to retake as the etching solution of the silicon wafer. The effectively utilization of the mixed waste acid solution discharged in the etching process allows the economical benefit to be remarkable, greatly reduces the discharge of the mixed waste acidsolution with strong acid components and have remarkable environmental benefit.

Description

technical field [0001] The invention relates to the technical field of the recycling of mixed solutions in the etching process, in particular to a recycling method of a solar silicon wafer texturing solution. Background technique [0002] At present, when wet etching silicon wafers, a mixed solution of hydrofluoric acid and nitric acid is usually used, and the proportion of these solutions varies according to the type of processing equipment. When etching silicon wafers, in order to maintain the same etching effect, hydrofluoric acid and nitric acid should be replenished in time, and the generated fluorosilicic acid should be separated and removed in time. The traditional method is to quantitatively analyze the components of the mixed solution after use to determine the amount of supplementation, which requires complicated operations and a long time, and can only be judged based on experience; The increase of impurity content affects the etching effect. SUMMARY OF THE INV...

AI Technical Summary

Problems solved by technology

The traditional method is to quantitatively analyze the components of the mixed solution after use to determine the replenishment amount, which requires complicated operations and a long time, and can only be judged based on experience; Increased impurity content will affect the etching effect