Method for manufacturing integral heater for carbon/carbon polycrystalline silicon ingot furnace

Abstract

The invention discloses a method for manufacturing an integral heater for a carbon / carbon polycrystalline silicon ingot furnace. The method comprises the following steps of: winding carbon cloth or needled carbon felts on which resin is painted on a steel mold core layer after layer to obtain a prefabricated body; performing pressurized curing, carbonization and chemical vapor deposition densification treatment until the density of a heater product is more than or equal to 1.50 g / cm<3>; performing machining to achieve a shape and a size required by a customer; and performing high temperature purification treatment through a chemical vapor deposition (CVD) silicon carbide protective layer to obtain the integral heater for the carbon / carbon composite polycrystalline silicon ingot furnace. Compared with the conventional carbon material heater, the raw material consumption of the integral heater is lowered by over 90 percent; and a CVD surface deposition silicon carbide protective layer is formed on the surface of the product, so that corrosion of silicon steam, oxygen and the like on the product is blocked and service life is prolonged by at least more than one time.

Description

technical field [0001] The invention relates to an industrial heater applied to a polysilicon ingot furnace capable of melting and casting silicon material at high temperature to form a large-size square silicon ingot, and specifically introduces the structure and preparation method of a carbon / carbon composite integral heater. Background technique [0002] In the world's photovoltaic industry, polysilicon wafers occupy a dominant position in solar cells due to their advantages of high production capacity, low energy consumption, and low cost. Most of the polysilicon ingot heaters are still graphite heaters. But as the polysilicon ingot furnace is getting bigger and bigger, the graphite heater is getting bigger and bigger. Because large-size graphite products are extremely difficult to form and expensive, polysilicon manufacturers find it hard to accept. There are generally heaters on the market that assemble multiple graphite plates by screws. For example, Chinese patent ...

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Problems solved by technology

The main disadvantages of the above two inventions are that the cutting workload is large, the material consumption is large, and the cost is high; the heater has not been treated with an anti-oxidation coating, and it is easy to undergo oxidation-reduction reactions with the quartz crucible, and the service life of the heater is relatively short