Device for purifying polysilicon by shell melting method, and method

A polycrystalline silicon and solar-grade technology, applied in chemical instruments and methods, silicon compounds, inorganic chemistry, etc., can solve the problems of slow flow rate of silicon melt, slow impurity removal rate, secondary pollution, etc.

Inactive Publication Date: 2011-05-11
陈庆汉
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0008] In order to solve the problem of secondary pollution caused by the use of non-silicon material crucibles in the prior art, the purpose of the present invention is to provide a device for manufacturing solar-grade polysilicon, using shell melting technology, using high-purity or solar-grade high-purity silicon fusion shells as The crucible containing the silicon melt eliminates the pollution of the crucible material to the high temperature silicon melt in the previous technology
[0009] In order to solve the problem that the flow rate of silicon melt is relatively slow when graphite resistance or graphite induction heating is used in the prior art, so the impurity removal rate of high-temperature vacuum melting and plasma atmosphere refining mainly relying on surface volatilization and reaction is also relatively slow. Another purpose of the invention is to provide a technical means, using the strong electromagnetic stirring effect of the ultra-high frequency electromagnetic field on the silicon melt, so that the rate at which each part of the silicon melt is exposed to the surface through convection is greatly increased, thereby greatly strengthening the main dependence on the silicon melt. The impurity removal rate of high temperature vacuum melting and plasma atmosphere refining based on surface reaction and volatilization

Method used

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  • Device for purifying polysilicon by shell melting method, and method
  • Device for purifying polysilicon by shell melting method, and method

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0040] 1. Form a melting shell crucible and melt the polysilicon raw material in it:

[0041] Raise the water-cooled chassis to the lower edge of the annular water-cooled copper tube, and then apply silicon powder slurry with a purity of 4N on the annular water-cooled copper tube and the water-cooled chassis to form a container, and load 4N ​​polysilicon blocks to the upper edge of the copper tube.

[0042] Vacuum the furnace to 10 -3 Pa, filled with argon flow for 10 minutes; then start the argon plasma spray gun, ionization frequency 3MHz, power 60KW, melt a molten pool in the upper center of the polysilicon block, when the diameter of the molten pool reaches 20mm or more, start the ultra-high frequency induction The heating coil is directly coupled with the silicon molten pool and the power is gradually increased. The induction heating frequency is 1.3MHz and the power is 200KW to gradually expand the silicon molten pool. At the same time, the feeder is continuously fed unt...

Embodiment 2

[0053] 1. Form a melting shell crucible and melt the polysilicon raw material in it:

[0054] Raise the water-cooled chassis to the lower edge of the annular water-cooled copper tube, and then apply silicon powder slurry with a purity of 6N on the annular water-cooled copper tube and the water-cooled chassis to form a container, and load 4N ​​polysilicon blocks to the upper edge of the copper tube.

[0055] Vacuum the furnace to 10 -3 Pa, filled with argon flow for 20 minutes; then start the argon plasma spray gun, ionization frequency 3.5MHz, power 100KW, melt a molten pool in the upper center of the polysilicon block, when the diameter of the molten pool reaches 20mm or more, start the ultra-high frequency The induction heating coil is directly coupled with the silicon molten pool and the power is gradually increased. The induction heating frequency is 1.8MHz and the power is 200KW, so that the silicon molten pool is gradually expanded, and the feeder is continuously fed unt...

Embodiment 3

[0066] 1. Form a melting shell crucible and melt the polysilicon raw material in it:

[0067] Raise the water-cooled chassis to the lower edge of the annular water-cooled copper tube, and then apply silicon powder slurry with a purity of 6N on the annular water-cooled copper tube and the water-cooled chassis to form a container, and load AN polysilicon blocks to the upper edge of the copper tube.

[0068] Vacuum the furnace to 10 -3 After Pa, fill with argon gas and flow for 30 minutes; then start the argon plasma spray gun with an ionization frequency of 4.5MHz and a power of 100KW to melt a molten pool in the upper center of the polysilicon block. When the diameter of the molten pool reaches 20mm or more, start the ultra-high frequency The induction heating coil is directly coupled with the silicon molten pool and the power is gradually increased. The induction heating frequency is 2.5MHz and the power is 300KW to gradually expand the silicon molten pool. At the same time, t...

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PUM

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Abstract

The invention discloses a device for purifying polysilicon by adopting shell melting technology, which comprises a water cooling vacuum hearth, annularly arranged water cooling copper pipes, a water cooling base plate with a lifting device, a plasma torch, a feeder and ultrahigh frequency induction heating coils. The invention also discloses a method for manufacturing solar-grade polysilicon, which comprises the following steps of: forming a solid silicon shell-melting crucible, performing ultrahigh frequency and ultrahigh temperature vacuum melting and plasma atmosphere refining on silicon raw materials in the shell-melting crucible, and performing directional solidification.

Description

technical field [0001] The invention relates to the purification technology of polysilicon, in particular to a device and a manufacturing method for manufacturing solar-grade 6N polysilicon by adopting shell melting technology. technical background [0002] At present, solar power generation plays an important role in new energy policies proposed by countries around the world. Its most basic material is high-purity solar-grade polysilicon. The quality and cost of solar-grade polysilicon determine the development prospects of this industry. Now most manufacturers in the world use the improved Siemens method to produce electronic-grade polysilicon, which is mainly supplied to the IC industry and a small part to the photovoltaic industry. The production cost is relatively high, and the purity (9N-10N) is also much higher than the actual needs of solar-grade silicon (6N-7N) for power generation, which is a waste. In fact, in June 2008, Suzhou Astor Corporation (CSI) has publi...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01B33/037
Inventor 陈庆汉何雪梅李多加高尚久徐家跃展宗贵张道标
Owner 陈庆汉
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