Alkaline type washing method for block-shaped silicon raw materials

Abstract

The invention discloses an alkaline type washing method for block-shaped silicon raw materials. The alkaline type washing method comprises the following steps that the portions containing impurities in the block-shaped silicon raw materials are polished; polished silicon raw materials are stored in a clear-water pool for flushing and then placed in an alkaline liquor pool for steeping, and the residual impurities and glue liquor residues on the surface of the silicon raw materials are steeped and washed; and the silicon raw materials are sequentially stored into the clear-water pool for flushing and then into ultrasonic washing equipment for washing. From the working process, it is known that acid is not required in the washing process of the silicon raw materials by adoption of the alkaline type washing method for the block-shaped silicon raw materials, so that producing cost is lowered, the washing efficiency of the silicon raw materials is improved, and the processing difficulty and the processing cost of waste water are lowered.

Description

technical field [0001] The invention relates to the field of cleaning bulk silicon raw materials, in particular to an alkaline cleaning method for bulk silicon raw materials. Background technique [0002] In the field of optoelectronics, silicon is a very important and commonly used semiconductor raw material, and is the most ideal raw material for solar cells. The preparation process of silicon wafers is generally to clean the raw materials first, then cast the cleaned raw materials into ingots, then cut the silicon ingots after casting, and then cut the squared silicon ingots into slices. During the whole process, the washing of raw materials is very critical. It is best to use raw materials as raw materials for silicon, but the price of raw materials is too expensive, so recycled materials are added to raw materials for ingot casting during production, which greatly reduces the production cost of the enterprise. The recycled material is the part located on the surface o...

AI Technical Summary

Problems solved by technology

[0004] However, due to pickling, there are relatively many cleaning steps and the cleaning cycle is relatively long; in addition, the cost of the acid required for the pickling step plus the cost of acid solution treatment is much higher than the purchase of non-heavy metal or only ultra-high metals. The difference between the cost of recycled materials for a small amount of heavy metals and the cost of purchasing ordinary recycled materials; moreover, due to the strengthening of environmental protection in the whole society, the requirements for wastewater treatment are higher, and there are many kinds of metal ions in acidic wastewater, and its treatment is complicated. The degree and difficulty are much higher than that of alkaline wastewater

Images