A kind of ingot graphite guard plate and its manufacturing method

Abstract

The invention discloses an ingot casting graphite guard board and a manufacturing method thereof.The method comprises the steps of manufacturing a bonding additive and a bonding agent; coating the outer side face of a graphite guard board body with the bonding additive; coating the outer side face of the graphite guard board body with the bonding agent, wherein the bonding agent above the horizontal center line of the outer side face of the graphite guard board body is set to be 0.5-1 mm, the bonding agent below the horizontal center line of the outer side face of the graphite guard board body is set to be 1-5 mm, and the bonding agent on the inner side face of the graphite guard board body becomes thicker gradually from top to bottom; curing the bonding agent onto the graphite guard board body.By the adoption of the ingot casting graphite guard board and the manufacturing method thereof, the difference of temperature between the upper portion and lower portion of the guard board can be reduced, stress on the guard board is made to be relatively uniform, the service life of the graphite guard board is prolonged, production cost is reduced, the transverse temperature gradient of the lower middle portion of a crucible is reduced, and defect proliferation is inhibited so as to improve the conversion efficiency of a silicon ingot battery.

Description

technical field [0001] The invention belongs to the technical field of photovoltaic equipment, in particular to an ingot graphite guard plate and a manufacturing method thereof. Background technique [0002] At present, in the production process of polycrystalline ingots, because the strength of the quartz crucible is not high, the entire ingot casting process is carried out under high temperature conditions, so the crucible is easy to crack and cause safety accidents. Graphite shield is an ideal crucible protection material because of its large thermal expansion coefficient and high temperature resistance. However, due to the characteristics of the thermal field of polycrystalline ingots, and the upper part of the crucible used in mainstream production is wider than the lower part, the degree of tightness between the guard plate and the upper and lower parts of the crucible is different, resulting in a shorter service life of the graphite guard plate and higher production c...

AI Technical Summary

Problems solved by technology

However, due to the characteristics of the thermal field of polycrystalline ingots, and the upper part of the crucible used in mainstream production is wider than the lower part, the degree of tightness between the guard plate and the upper and lower parts of the crucible is different, resulting in a shorter service life of the graphite guard plate and higher production costs. In addition, the distance between the middle and lower part of the crucible is relatively far from the top and side heaters, resulting in an excessive lateral temperature gradient in the middle and lower part of the crucible, which will also lead to rapid propagation of defects, thereby affecting the conversion efficiency of the produced silicon ingot battery

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