Linear cutting method of polycrystal casting ingot

Abstract

The invention relates to the technical field of polycrystal casting ingot linear cutting, in particular to a linear cutting method of a polycrystal casting ingot. The production method is as follows: firstly, marking: carrying out square opening on the polycrystal casting ingot to obtain silicon blocks, and identifying silicon blocks at the periphery of the edge of the casting ingot close to a crucible so as to distinguish A surfaces and B surfaces of the silicon blocks, wherein the B surfaces are close to the crucible, and the A surfaces are corresponding surfaces of the B surfaces; secondly, carrying out IR (infrared radiation) test, LT test, disconnection and surface grinding on the silicon blocks after the square opening; thirdly, bar sticking, comprising the steps of sticking the B surfaces of the silicon blocks with the A surfaces and the B surfaces on a crystal support, sticking bars on the other silicon blocks as usual, and after the curing of mucilage glue, adding the bars and cutting wafers; and fourthly, wafer cutting: cutting the wafers on the cured silicon blocks, and distinguishing the A surfaces of the silicon blocks with the A surfaces and the B surfaces as knife entering surfaces. In the linear cutting method, as the A surfaces with less impurities and hard points are adopted as the knife entering surfaces, steel wires are easier to enter a crystal, so that bad records such as wire jumping and edge jumping and the like are greatly reduced, the wafer discharging rate of silicon wafers is improved greatly, the cutting cost of the silicon wafers is reduced and the economical efficiency of enterprises is improved.

Description

technical field [0001] The invention relates to the technical field of polycrystalline ingot wire cutting. Background technique [0002] In the current process of growing polycrystalline ingots, crystals are crystallized and grown using ceramic crucibles as carriers. In order to prevent silicon crystals from adhering to the crucible and causing adverse effects such as cracking of the ingot, the crucible needs to be sprayed with SiNx fine powder during the ingot casting process. In this way, during the crystal growth process, the SiNx impurities in the crucible and the surface coating preferentially diffuse to the polysilicon ingot close to the crucible, resulting in the surface metal impurities and SiC, SiN, SiCNx and other internal polysilicon with significantly higher hardness coefficients. At present, in the polycrystalline ingot slicing process, the process methods generally used are: squaring, truncation, grinding, sticking rods, and wire cutting. When sticking the ro...

AI Technical Summary

Problems solved by technology

[0003] The technical problem to be solved by the present invention is to provide a wire cutting method for polycrystalline ingots, which solves the problem of low qualification rate of silicon block slices where the edges of

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