A thermal insulation structure for the upper part of a sapphire single crystal furnace

Abstract

The invention provides a thermal insulation structure for the upper part of a sapphire single crystal furnace. The structure consists of circular support structure, zirconia insulation layer and molybdenum heat shield from top to bottom. The fixed support structure is a single-layer circular stainless steel plate. The molybdenum heat shield is composed of multi-layer molybdenum sheets. The zirconia bricks made by sintering zirconia fibers are assembled. There are circular center holes and rectangular observation holes on the molybdenum sheet. Molybdenum bolts and molybdenum nuts are used between the circular support structure, zirconia insulation layer and molybdenum heat shield. The connection is fixed. The invention can reduce the heat loss of the upper part, enhance the heat preservation effect, establish a reasonable temperature gradient, and make the temperature field easier to adjust, thereby solving the problem of the molybdenum upper heat shield structure used in the traditional Kyropoulos single crystal furnace in the high temperature environment. The inner and upper parts dissipate heat quickly, the temperature field is not reasonable enough, and the temperature adjustment is difficult to control.

Description

(1) Technical field [0001] The invention relates to a thermal field structure in a crystal growth furnace, in particular to an upper heat preservation structure in a single crystal furnace for growing sapphire by a cold-heart shoulder micro-pulling method. (2) Background technology [0002] Sapphire is an aluminum oxide (Al 2 o 3 ) single crystal, belonging to the hexagonal crystal system. Sapphire crystal has good light transmission from near ultraviolet (190nm) to mid-infrared. Therefore, it is widely used in optical components, infrared devices, and high-strength laser lens materials. In addition, it has the characteristics of high hardness, high temperature resistance, and corrosion resistance, and has been widely used in the industry in recent years. In particular, optical-grade large-size sapphire materials have become a hot spot in research, development and industrialization at home and abroad in recent years because of their stable performance, large market deman...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to provide a method that can reduce the heat loss of the upper part, enhance the heat preservation effect, establish a reasonable temperature gradient, and make the temperature field easier to adjust, so as to solve the problem of the high temperature of the molybdenum upper heat shield structure used in the traditional Kyropoulos single crystal furnace. The thermal insulation structure of the upper part of the sapphire single crystal furnace has problems such as fast heat dissipation in the upper part of the furnace during use in the environment, unreasonable temperature field, and difficult control of temperature regulation.

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