Vacuum furnace suitable for preparing large-diameter high-purity polysilicon ingot

Abstract

The invention relates to an ingot vacuum furnace which is suitable for making polysilicon with large size and high purity. An insulating cover is designed to be a lifting type. A main body of a lifting mechanism consisting of a servo linear motion mechanism and a continuous-motion bar is arranged on a furnace cover, wherein, one end of the continuous-motion bar is fixedly arranged on the top of the insulating cover. An electrode of a power supply part is a water cooling type. A transmission cable in the furnace is a flexibility water cooling type. As a material platform and a crucible are free from the working interference of the lifting mechanism, a fixed type of the crystallization quality is beneficial to being ensured. The volume size in the crucible is only related to the bearing ability of the material platform; therefore, the crucible with large capacity is easy to be arranged. Furthermore, the water cooling type of the upper and lower electrodes and the water cooling type of the flexibility cable are adopted to ensure the reliable service life, thus ensuring the free lifting of the insulating cover. The ingot vacuum furnace has the advantages of scientific and reasonable structure, reliable working, long service life, stable product quality and high purity, which is suitable for producing polysilicon with large size and high purity and has strong practicability.

Description

technical field [0001] The invention relates to metal smelting equipment, in particular to a vacuum furnace suitable for manufacturing large-scale high-purity polysilicon ingots. Background technique [0002] Polycrystalline silicon wafer is a basic material for manufacturing solar silicon cells. The polycrystalline silicon ingot used to manufacture polycrystalline silicon wafers for solar silicon cells requires high purity. The polycrystalline silicon solution melted at high temperature in a vacuum furnace crucible usually presents a three-layer structure. The bottom is The impurity layer with a heavier specific gravity, the upper part is a slag-containing layer with a lighter specific gravity, and only the middle layer is a usable layer with a relatively pure texture. For a small crucible, due to its small volume, the impurity layer at the bottom is relatively close to the slag-containing layer at the upper part, not only the obtained intermediate usable layer is often ver...

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Problems solved by technology

[0003] The purpose of the present invention is to provide a vacuum furnace suitable for manufacturing large-scale high-purity polysilicon ingots, so as to completely reverse the problem that the polysilicon ingot crystallization furnace in the prior art is easily disturbed by a mechanical lifting mechanism and affects the crystallization quality. Reasonable structural form and overcome the disadvantages that are not suitable for casting large-size, high-purity polysilicon ingots

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