A kind of classification method after sapphire substrate sheet is sliced

Abstract

A method for sorting sapphire substrates after slicing according to the present invention is to sort the sliced ​​sapphire substrates according to the Warp value, wherein the substrates with Warp<16 μm are directly subjected to double-sided in-line boron carbide grinding; 16 μm≤Warp Substrates <25μm are annealed at 1400°C for 12 hours, and then double-sided in-line boron carbide grinding; substrates with 25μm≤Warp<35μm are annealed at 1400°C for 12 hours, and then double-sided by circulating boron carbide Grinding, such a classification management method can effectively avoid the problem of direct selection of circular boron carbide double-sided grinding, the rapid decline in efficiency, the obvious increase in the later grinding time, and the increase in grinding costs. It can also effectively avoid the warp value when using in-line boron carbide double-sided grinding The warp value of substrates ≥25μm is too large after grinding, which leads to the problem of secondary rework or even scrapping, which improves the yield rate and saves costs.

Description

technical field [0001] The invention relates to the technical field of sapphire crystal manufacturing, in particular to a method for classifying sapphire substrate slices after being sliced. Background technique [0002] Sapphire (A-alumina) crystal material is a colorless and transparent single crystal material with a series of excellent comprehensive physical and chemical properties such as high strength, high hardness (Mohs scale 9), high temperature resistance, and good chemical stability. It is widely used in high brightness LED substrate material. [0003] When the sapphire substrate transitions from 2 inches to 4 inches, the simple stress difference between the polishing surface and the grinding surface cannot control the bending of the sapphire substrate to the polishing surface, and the substrate surface shape will follow the wafer in the SagX and SagY directions The degree of warp (Warp) presents different Bow values. The current 4-inch sapphire substrate slices ...

AI Technical Summary

Problems solved by technology

The current 4-inch sapphire substrate slices are managed in batches of ingots after being sliced, and there are two processing methods for the subsequent grinding process: one is to circulate the entire batch of 4-inch sapphire substrate slices after slicing. Surface grinding, this method has the following disadvantages: Circular grinding is accompanied by an increase in the number of cycles, its grinding efficiency drops rapidly, and the length of subsequent grinding increases significantly; due to the increase in grinding time, a large increase in grinding equipment and operators is required. The processing cost is reduced; one is to carry out in-line boron carbide double-sided grinding on the entire batch of 4-inch sapphire substrates after slicing. This method has the following defects: some sapphire substrates with Warp values ​​≥ 25 are Warp after grinding. The value is too large, resulting in secondary rework or even scrapping