Straight pulling single crystal furnace and processing method of carbon-carbon composite material for straight pulling single crystal furnace

Abstract

The invention discloses a processing method of carbon-carbon composite material for a straight pulling single crystal furnace. The method comprises the steps of processing carbon fiber into a prefabricated body, then heating the prefabricated body in a chemical deposition furnace to 1050-1150 DEG C, and introducing propane gas, wherein the propane gas is decomposed at high temperature to generate carbon and the carbon is deposited in the prefabricated body; placing the compacted prefabricated body in a graphitization furnace; heating to 2300-2800 DEG C, and maintaining the temperature for 2-4 hours and cooling to form the carbon-carbon composite material. The invention further discloses the straight pulling single crystal furnace which comprises a heater processed by the carbon-carbon composite material. Density of the heater is greater than or equal to 1.8g / cm<3>. The processing method of the carbon-carbon composite material provided by the invention replaces a method of repeated impregnation by carrying out compacting treatment to the prefabricated body by using the chemical vapor deposition furnace, so that not only is the process simple, but also more impurities do not be doped in the compacting treatment process, and high temperature purification is not needed, thereby greatly simplifying the processing method.

Description

technical field [0001] The invention relates to the field of photovoltaics, in particular to a processing method for a carbon-carbon composite material used in a Czochralski single crystal furnace and a Czochralski single crystal furnace used for producing single crystal silicon. Background technique [0002] The Czochralski single crystal furnace is mainly used to melt polycrystalline materials such as polysilicon, and grow dislocation-free single crystal equipment using the Czochralski method. During the processing, a suitable thermal field is required, that is, the entire process of maintaining the single crystal growth under a certain temperature gradient. heat system. If the thermal field does not meet the single crystal growth conditions, the quality of the grown single crystal is poor, with dislocations and other structural defects, or it is easy to make the single crystal become polycrystalline, or even fail to seed. Therefore, the thermal field configuration of the...

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Problems solved by technology

However, since the above-mentioned processing method adopts the method of repeatedly impregnating asphalt and resin to densify the heater prefabricated body, in this process, repeated impregnation is required, which makes the processing method more cumbersome, and the heater prefabricated body will be doped with more The impurities need to be purified by high temperature, and the high temperature purification is relatively complicated, which increases the difficulty of the processing method to a certain extent

At present, the processing method is still in the stage of small batch test, and the application technology is not yet mature.

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