Crucible adhesion preventing method of polycrystalline ingot casting

Abstract

The invention discloses a crucible adhesion preventing method of polycrystalline ingot casting. The method comprises coating a solid-liquid interface area of the inner surface of a crucible by a circle of a first crucible adhesion preventing coating with a first preset thickness, and spraying the whole area of the inner surface of the crucible by a second crucible adhesion preventing coating witha second preset thickness. According to the crucible adhesion preventing method of polycrystalline ingot casting, the crucible can be prevented from being adhered, a silicon ingot is prevented from edge failure and cracking, the quality of the silicon ingot is improved, and the production cost is reduced.

Description

technical field [0001] The invention belongs to the technical field of photovoltaic cells, in particular to an anti-sticking crucible method for polycrystalline ingots. Background technique [0002] With the development of the photovoltaic industry, crystalline silicon solar cells have gradually occupied the dominant position in the photovoltaic industry, and the cost of silicon wafers accounts for more than half of the cost of single / polycrystalline silicon, so the cost of silicon wafers is reduced and the quality of silicon wafers is improved. , increasing the photoelectric conversion efficiency of silicon wafers is of great significance to the development of the photovoltaic industry. [0003] In the prior art, in order to prevent the molten silicon from reacting with the quartz ceramic crucible and easy to be demoulded and separated during the polysilicon ingot casting process, a layer of high-purity silicon nitride is brushed on the inner surface of the crucible, which ...

AI Technical Summary

Problems solved by technology

However, during the melting process of the polycrystalline ingot, the silicon liquid fluctuates greatly, which has a strong scouring effect on the silicon nitride coating, especially the silicon nitride at the interface of the silicon liquid, that is, the three-phase interface, causing the coating to fall off and prone to sticking. crucible

If there is a sticky crucible at the solid-liquid interface on the upper surface of the silicon ingot, it may cause a small part of the silicon ingot to stick, or it may cause the silicon ingot to drop corners or even crack the entire silicon ingot, which will seriously affect the output and increase the ingot cost. cost, which in turn increases wafer cost

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