Tungsten screen sapphire furnace
At present, the single crystal sapphire crystal has been widely used in the optoelectric industry LED. However, the drawing of sapphire crystal needs to be done in a closed cavity, and the temperature of AL203 should be raised above the melting point of 2050°. Seed crystal is used to achieve a series of operations such as crystal leading, shoulder setting, equidiameter and end. Due to the need to reach such high temperature inside the furnace, the thermal field of the sapphire furnace is made of tungsten and molybdenum materials, and in order to get high-quality sapphire crystal, the design of the thermal field often needs to meet the temperature environment suitable for sapphire crystal growth.
The traditional tungsten molybdenum sapphire furnace insulation products are simply symmetrically installed inside the furnace, so as to form a balanced temperature environment, but often can appear in the process of installing the offset, and after many experiments thermal field itself also can appear different degree of deformation, which can cause in the process of heating furnace temperature is more and more uneven, which seriously affected Control the temperature in the furnace and the integrity of the crystal during the whole process.
A sapphire furnace with a rotating insulating tungsten screen can solve this problem. In the process of crystal pulling, insulating tungsten screen through the rotation of the motor drive for low speed is slow, the temperature distribution of cavity in the body is more uniform, and can be more effective in the process of the formation of crystal pulling to temperature gradient, need to see at the time of the led chip, the emergence of the cold heart, and in the crystal growth rate and the complete crystal shape control are very favorable.
