Isostatic graphite is a very important material in photovoltaics and semiconductors. With the rapid rise of domestic isostatic graphite companies, the monopoly of foreign companies in China has been broken. With continuous independent research and development and technological breakthroughs, the performance indicators of some of our core products are on par with or even better than those of international competitors. However, due to the dual impact of falling raw material prices and cost reductions by end-user customers, prices have continued to decline. Currently, the profits of domestic low-end products are less than 20%. With the continuous release of production capacity, new pressures and challenges are gradually brought to isostatic graphite companies.
1. What is isostatic graphite?
Isostatic graphite refers to graphite materials produced by isostatic pressing. Because isostatically pressed graphite is pressurized uniformly and steadily by liquid pressure during the molding process, the graphite material produced has excellent properties. Since its birth in the 1960s, isostatic graphite has become a leader among new graphite materials due to its unique properties and wide range of applications.
2. Isostatic graphite production process
The production process flow of isostatically pressed graphite is shown in the figure. Isostatic graphite requires structurally isotropic raw materials. The raw materials need to be ground into finer powders. Isostatic pressing molding technology needs to be applied. The roasting cycle is very long. In order to achieve the target density, multiple impregnation and roasting cycles are required. , the graphitization period is also much longer than that of ordinary graphite.
3. Application of isostatic graphite
Isostatic graphite has a wide range of applications, mainly in the semiconductor and photovoltaic fields.
In the field of photovoltaics, isostatically pressed graphite is mainly used in graphite components in the graphite thermal field in single crystal silicon growth furnaces and in the graphite thermal field in polycrystalline silicon ingot furnaces. Specifically, clamps for polycrystalline silicon material production, gas distributors for hydrogenation furnaces, heating elements, insulation cylinders and polycrystalline ingot heaters, directional blocks, as well as guide tubes for single crystal growth and other smaller sizes. parts;
In the field of semiconductors, heaters and insulation cylinders for sapphire single crystal growth can use either isostatic graphite or molded graphite. In addition, other components such as crucibles, heaters, electrodes, heat-insulating shielding plates, and seed crystals About 30 types of holders, bases for rotating crucibles, various circular plates, and heat reflection plates are made of isostatically pressed graphite.
Post time: May-06-2024