Tungsten Crucible for Quartz Continuous Melting Furnace

Quartz glass is a kind of special glass only made of silica, whose microstructure is a simple network which is made of tetrahedral structure of silica, having a compact structure. The optical property of transparent quartz glass is excellent. Except that, it also has an excellent transmittance in the range of continuous wave between ultraviolet and infrared radiation. Quartz glass formed by quartz continuous melting furnace can be widely applied in various processes of the semiconductor manufacturing.

Tungsten crucible has a high melting point, high boiling point with an excellent high temperature strength property, therefore, it is widely used in quartz continuous melting furnace. At present, the main process equipment is installing the molybdenum electrodes and 64molybdenum rods in heating device of quartz continuous melting furnace, these molybdenum electrodes and molybdenum rods would spread evenly around the wolfram crucible. When the electrodes are conducted by electricity and heating, as the conductive heating element, 64 molybdenum rods would make wolfram crucible continue heat up.

However, this process equipment has a serious flaw. When these 64 molybdenum rods are considered as the conductive heating element, there exist an 8-12mm distance between molybdenum rods which can cause heating of the wolfram crucible unevenly, thereby prolonging its heating time, it would greatly reduce the production effectiveness of quartz continuous melting furnace. In order to deal with this problem, users can install charge pipe and tungsten core rod on the top wolfram crucible of the furnace to protect the entrance of the gases. Putting a molding material platform whose central section should be designed with a forming port, and then put the heating unit on wolfram crucible external. Molybdenum rods can be replaced by molybdenum network and coverage the surface of wolfram crucible evenly. The uniform coverage of molybdenum network can make tungsten crucible be heating evenly, so that it can effectively solve the quality problems.

In addition to quartz continuous melting furnace, tungsten also plays an important role in powder metallurgy technology, electronic spraying, and crystal growth. The production of quartz glass requires the high tungsten carbide inserts purity quartz sand continue to flow into the tungsten tube of continuous furnace, the material continued to be melted at a temperature above 2000 ° C, and then flow continuously along the tungsten material table, finally, freeze it. Most of the materials would become deformation under the continuous high temperature, while the wolfram crucible can withstand the test of the process.