In the 21st century, the photovoltaic industry has developed rapidly, and the output and market of polycrystalline silicon ingot materials for solar cells have increased by leaps and bounds. This also provides a new market with broad development prospects for graphite products in the photovoltaic industry. Ingot polysilicon, an important raw material required for solar cell silicon wafers, has begun to use a large number of high-purity, high-quality graphite materials in the ingot furnace of its production equipment. In the production of ingot polysilicon equipment, many components require graphite materials. In particular, the heating material used in the ingot furnace heater-high purity graphite, and the heat insulation material used-high purity carbon felt insulation material, are both important and indispensable for the current ingot polysilicon equipment Supporting materials.

Because the heating temperature of the ingot furnace heater is very high (over 1600°C), its heating material must not react with the silicon material and cause no pollution to the silicon material, and it can be used in vacuum and inert atmosphere for a long time. The heaters that meet the conditions of use are metal tungsten, molybdenum and non-metal graphite. Because tungsten and molybdenum are expensive and difficult to process, graphite has a wide source and can be processed into various shapes. In addition, graphite has the characteristics of low thermal inertia, rapid heating, high temperature resistance, good thermal shock resistance, large radiation area, high heating efficiency, and stable basic performance. Because of this, graphite material has become a necessary heating material in ingot furnace heaters.