Method for casting large-sized silicon ingot

Abstract

The invention discloses a method for casting a large-sized silicon ingot, relating to the technical field of manufacturing methods of silicon ingots. The method comprises the following steps: (1) modifying a thermal field in a G5 ingot furnace till the thermal field is consistent with the arrangement requirements of a bottom plate, side plates and a crucible of the G6 ingot furnace, and arranging the bottom plate, the side plates and the crucible of the G6 ingot furnace in the thermal field; (2) heating; (3) melting; (4) crystallizing; (5) annealing; (6) cooling. By adopting the method, upgrade of the thermal field is realized on the premise of not changing large-sized thermal field components such as heaters, radiators and the like, and the yield of a Jinggong 500N ingot furnace is released to the maximum extent; meanwhile, the modification cost of the method is low, the original heating structure of the thermal field is not damaged, damage to thermal field components is eliminated, the thermal field can be directly changed into a G5 small-sized silicon ingot thermal field under an proper production demand, and convenience is brought to use.

Description

technical field [0001] The invention relates to the technical field of manufacturing methods of silicon ingots, in particular to a method for casting large-size silicon ingots using a small-size ingot casting furnace. Background technique [0002] At present, the photovoltaic industry is developing rapidly, and the development trend of polysilicon ingots in the direction of large size is obvious. At the same time, under the pressure of market costs, increasing the production capacity of ingot furnaces on the basis of existing equipment has become an important way to further reduce the cost of silicon ingots in the ingot process. [0003] Taking Jinggong 500N ingot casting furnace as an example, the thermal field design ingot weight is 500kg, and the thermal field profile is as follows Figure 4 As shown, the top rod-shaped heater is used as the heat source, and the bottom uses a water-cooled copper plate to dissipate heat. The water-cooled copper plate and the internal therma...

AI Technical Summary

Problems solved by technology

Adding a bottom heater under the Jinggong 500N ingot cooling table is expensive, and after adding the bottom heater, the heater is too close to the bottom water-cooled copper plate. If the power output is too large, the thermal field temperature at the bottom of the cooling table will be too high, and the water cooling An increase in the water temperature in the copper plate will easily cause the cooling water to vaporize, causing danger; the low power output of the bottom heater will not be able to effectively heat the silicon material at the bottom, so a heater is added at the bottom to solve the problem of Jinggong 500N casting There are great difficulties and potential safety hazards in the problem of slow material change when sizing silicon ingots

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