Thermal Field Structure of Polycrystalline Ingot Furnace for Large Size Silicon Ingot

Abstract

The invention relates to a novel thermal field structure of a large-size silicon ingot polycrystal ingot furnace. The novel thermal field structure comprises a thermal insulation cage defined by an upper insulating plate, a lower insulating plate and side insulating plates, wherein a gas inlet pipe extending into the thermal insulation cage is arranged on the upper insulating plate, a directional solidification block is arranged on the lower part in the thermal insulation cage, a plurality of graphite supporting pillars for supporting the directional solidification block are arranged on the lower part of the directional solidification block, a graphite crucible is arranged on the directional solidification block, a quartz crucible is arranged in the graphite crucible, graphite heaters are arranged around the graphite crucible, and a thermal insulation plate fixed together with the side insulating plates is arranged between the periphery of the bottom of the graphite crucible and the side insulating plates. The large-size silicon ingot can be cast by redesigning and distributing the internal structure, appearance and size of a thermal field, and the production capacity can be greatly improved; and special heating devices and gas inlet devices are matched with a large-size silicon ingot casting technology so as to control a desirable long crystal solid-liquid interface, impurities can be effectively removed, the crystal defects can be reduced, and the crystalline quality of the large-size silicon ingot can be effectively improved.

Description

technical field [0001] The invention relates to polysilicon production equipment, in particular to an ingot furnace thermal field structure for producing large-size polysilicon ingots by directional solidification in the solar photovoltaic industry. Background technique [0002] At present, the photovoltaic industry is developing rapidly, and market competition is stimulating. Improving the quality of silicon ingots and reducing production costs have become the top priorities. Large-size polysilicon ingots have become the current development trend. Continuously increasing the weight of polysilicon ingots and saving energy and reducing consumption are the next steps to reduce costs. way. [0003] The silicon ingots that can be produced by the thermal field of the existing polysilicon ingot casting furnace mainly include: silicon ingots with a weight of 450kg, silicon ingots that can be prescribed 25 silicon blocks, that is, G5 silicon ingots; silicon ingots formed by vertical...

AI Technical Summary

Problems solved by technology

Conventional polysilicon ingot thermal field, the temperature distribution is not suitable, and the quality improvement is not obvious

[0006] Existing polycrystalline ingot furnaces are equipped with top and bottom heaters, especially the G5 polycrystalline ingot furnace, which has a small amount of charge, and its thermal field structure is not conducive to the growth of large-sized silicon ingots, and the solid-liquid interface during the crystal growth process It is also convex and concave, which is not conducive to the removal of impurities during the crystal growth process, and has a greater impact on the overall quality of the crystal.

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