High purity graphite generally refers to the amount of carbon containing more than 99.99% of graphite in the organizational structure can be divided into three categories: coarse grain structure, fine grain structure and fine grain structure. The base material for integrated circuits is mainly single crystal silicon chip, silicon single crystal growth process is currently mainly used in Czochralski (CZ) method, and other methods of magnetic Czochralski method (MCZ), regional (FZ) method and double crucible pulling method, the total amount of single crystal silicon 80% monocrystalline silicon with the global electronics industry. Czochralski graphite furnace is monocrystalline silicon using consumables, high purity graphite materials into the heating system of monocrystalline silicon furnace. In 2005 China needs to be directly drawn silicon single crystal furnace with graphite about 800 t. [1]
Another important use of high purity graphite is processed into various kinds of crucible, used for the production of precious metals, rare metals or high pure metal, non-metallic materials. Graphite electrode is also a kind of high purity graphite, which can be used for the spectral analysis of all elements except for carbon. The impurity content of finished product should be less than 6*10 were prepared by chemical method and standard sample collection for impurity spectrum of pure carbon powder or graphite pure spectrum in spectrum analysis, the two kinds of high purity materials of impurity content requirements are at 6 *10; in some cases, to the carbon content reached 99.9995% the total ash content of less than 5 *10. The molding methods of high purity graphite include three kinds of forming methods, such as extrusion, molding, and static pressing. Table 9 the physical and chemical properties of high purity graphite products made in China
