Mold used for manufacturing crucible

Abstract

The invention discloses a mold used for manufacturing a crucible. A non-water-absorption mold core is arranged in a water absorption tank body. The water absorption tank body is matched with the non-water-absorption mold core so that a cavity for paste to be poured therein can be formed between the water absorption tank body and the non-water-absorption mold core. According to the mold, due to the fact that the non-water-absorption mold core is used, impurities and fine particles in the paste are prevented from moving inwards, the impurities and the fine particles in the paste are made to move towards the outer wall of the crucible only by absorbing the paste outwards through the external water absorption tank body, and therefore purity and roughness of the inner wall of the crucible are improved, the quality of polycrystalline silicon ingots is improved, the adhesion of silicon nitride release agents is enhanced, and the crucible adhering phenomenon is avoided.

Description

technical field [0001] The invention relates to the field of photovoltaic technology, in particular to a mold for making a crucible. Background technique [0002] Quartz ceramic crucible has the advantage of high temperature resistance and can be used to hold high temperature molten silicon material. Generally speaking, the grouting method is used to make quartz ceramic crucibles. This method is not only mature in technology, but also stable in quality. Since in the solar polysilicon ingot industry, the purity of the silicon material is required to be above 6N, the purity requirement for the crucible is also relatively high. [0003] The mold used in the grouting method in the prior art is mainly made of the mold core in the middle and the side mold of the periphery, and the mold core and the side mold are all made of gypsum with water absorption. When the aqueous slurry is injected into the mould, the gypsum The mold core and gypsum side molds absorb the water in the slur...

AI Technical Summary

Problems solved by technology

In this way, during the process of ingot casting polysilicon, the inner wall of the quartz ceramic crucible in contact with high-purity silicon will cause metal impurities and other pollution to the polysilicon crystal, thereby reducing the minority carrier life of solar silicon wafers, and spraying on the inner wall of the crucible during ingot casting Silicon nitride release agent, which requires the inner wall of the crucible to have a certain roughness to prevent the occurrence of sticky crucible and the introduction of impurities caused by the falling off of silicon nitride, while the inner wall of the crucible made by the double-sided slurry suction process in the prior art is relatively smooth , not easy to adhere to silicon nitride

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