Multistage graphite heating system of sapphire crystal growth equipment and using method of multistage graphite heating system

Abstract

The invention belongs to the technical field of sapphire crystal growth furnace equipment, and provides a multistage graphite heating system of the sapphire crystal growth equipment and a using method of the multistage graphite heating system. The multistage graphite heating system comprises an upper heater, a middle heater, a bottom heater, three power supply devices, a growth furnace cavity, a crucible device and a heat preservation layer, wherein the growth furnace cavity comprises a small furnace cover, a large furnace cover, a furnace cylinder and a furnace base plate; the crucible device comprises a crucible, a crucible tray and a crucible supporting column; each of the upper heater and the middle heater comprise a continuous S-shaped fence-shaped graphite cylinder, four graphite round columns, two long water cooling copper electrodes and two short water cooling copper columns; the bottom heater comprises an S-shaped fence-shaped graphite disc, two graphite electrodes and a water cooling copper electrode; the three individually controlled power supplies are connected with water cooling cables of the upper heater, the middle heater and the bottom heater. The multistage graphite heating system of the sapphire crystal growth equipment and the using method of the multistage graphite heating system have the advantages that the temperature gradient requirement for the growth of large-sized sapphire crystals at each stage can be met, the cost can be reduced, and the quality can be improved.

Description

technical field [0001] The invention belongs to the technical field of sapphire crystal growth furnace equipment, and in particular relates to a multi-stage graphite heating system of sapphire crystal growth equipment and a use method thereof. Background technique [0002] Sapphire crystal is a single crystal of α-alumina, with a melting point of about 2050°C and a boiling point of close to 3500°C. It can work under the harsh conditions of high temperature of 1900°C. High light transmittance, the transmittance is as high as 85% under the condition of 3-5μm, strong radiation resistance, good thermal shock resistance, and super corrosion resistance. It is widely used in infrared military devices, satellite space technology, In the fields of window materials for high-intensity lasers, bell jars for supersonic missiles, and windows for submarines; furthermore, because the lattice structure of sapphire is relatively close to that of gallium nitride, it is widely used in the comme...

AI Technical Summary

Problems solved by technology

Metals or alloys are easily deformed at high temperatures, become thinner after volatilization or oxidation, thicker after absorbing volatiles, and the microstructure of the tungsten rod changes due to the growth of metal grains, which greatly shortens the heater’s lifespan. service life

[0005] In large-sized sapphire crystal growth equipment, usually a metal heater with a price of 30,000 yuan can only be used 8 times, resulting in very expensive production costs. Compared with metals with high melting points, graphite has excellent high-temperature performance, including high-temperature Therefore, graphite is also used to manufacture heaters for sapphire crystal growth equipment; the existing graphite heaters are single-stage, which cannot overcome the shortcomings of small temperature gradients, and in Inability to grow large-sized sapphire crystals head-to-tail, leading to poor production quality

So far, there is no graphite heater used in the Kyropoulos growing sapphire in the world, and the single-stage graphite heater cannot be applied to the large-sized Kyropoulos growing sapphire equipment at all.

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