85kg to 120kg sapphire crystal growth automatic control method

Abstract

The invention discloses a method for automatically controlling growth of 85-120kg sapphire crystals. The method comprises the step of sapphire crystal seeding and is characterized in that an electronic weighing device used for measuring the crystal weight is arranged in a single crystal furnace and sends a weight signal to a PLC (programmable logical controller) system; after sapphire crystal seeding is finished, the PLC judges the crystal growth stage in the growth process according to the crystal weight, calls out the process parameter packet of the corresponding stage and adjusts the parameters via PID (proportion integration differentiation); when the crystal net weight measured by the electronic weighing device exceeds 3-5kg, the PLC adjusts the temperature reduction amplitude and controls the sapphire crystals to grow in an isodiametric manner; when the crystal weight measured by the electronic weighing device exceeds 45-70kg, the PLC adjusts the temperature reduction amplitude and controls growth of the sapphire crystals to end; and when the reduction amplitude of the heater powder computed by the PLC exceeds 15-20%, the sapphire crystals are automatically transferred to the cooling and inflating stage and leave from the pot, thus completing growth.

Description

Technical field

[0001] The invention belongs to a large-size sapphire crystal growth automatic control technology executed after seeding is completed, in particular to an 85kg to 120kg sapphire crystal growth automatic control method. Background technique

[0002] The composition of sapphire is alumina (Al 2 O 3 ), is composed of three oxygen atoms and two aluminum atoms covalently bonded together, and its crystal structure is a hexagonal lattice structure. It is often used in A-Plane, C-Plane and R-Plane. Due to the wide optical penetration band of sapphire, it has good light transmittance from near ultraviolet light (190nm) to mid-infrared. Therefore, it is widely used in optical components, infrared devices, high-intensity laser lens materials and mask materials It has the characteristics of high sound velocity, high temperature resistance, corrosion resistance, high hardness, high light transmittance, and high melting point (2045℃). It is a very difficult material to process,...

Images