Cutting method of crystalline silicon blocks

Abstract

The invention relates to a cutting method of crystalline silicon blocks, a crystalline silicon block to be cut is placed on a section cutter platform, a plurality of line-shaped saws are horizontally distributed and spray mortar so as to cut the crystalline silicon block; and the method is characterized in that: the two end surfaces of the crystalline silicon block are polished to be level before being cut, and the line-shaped saws are parallelly distributed at equal intervals, with the width of shorter than the length of the crystalline silicon block to be cut. The technical proposal improves the 'climbing' phenomenon in the cutting process of the crystalline silicon block, and well solves the problems of wire-break and line-skipping caused by that silicon fragments generated in the cutting process of the crystalline silicon block drop to the line-shaped saw net or an idler pulley.

Description

technical background [0001] The invention belongs to the technical field of crystalline silicon block processing and silicon wafer preparation, and particularly relates to a polysilicon block cutting method for improving the slicing yield of the crystalline silicon block. Background technique [0002] Crystalline silicon wafers are widely used in the field of microelectronics or solar cells. They are made of silicon materials by Czochralski or ingot casting methods into monocrystalline rods or polycrystalline silicon ingots, cubed, cut into silicon blocks and then sliced. The main working principle of its slicing is to stick silicon blocks of different lengths on a fixed length of viscose glass. The thin steel wire on the guide wheel with fine grooves drives the mortar supplied to the steel wire, and the silicon block is cut by the SiC fine powder in the mortar. [0003] With the rapid development of the solar photovoltaic industry in recent years, the industry has an incre...

AI Technical Summary

Problems solved by technology

The "climbing" phenomenon of the inclined surface in the slice can easily cause the vibration of the linear sawing net, cause jumping wires, and cause abnormal fluctuations in the linear sawing net as a whole. The vibration of the local linear sawing net near the end face is particularly obvious, usually Many defective chips are generated near the end face

[0006] Second, during the slicing process, it is very easy to produce tiny silicon fragments falling into the wire saw net or the guide wheel, which will also cause wire breakage and jumping, and may also cause damage to the guide wheel and reduce the service life of the guide wheel

In the study of bad pieces at the seams, it was found that if the slope of these seams is too large or not smooth enough during the slicing process, many waste pieces at the end will be produced.

Because the two ends connected at the seam together disturb the slicing process more, not only produce more bad pieces on the end faces, but also greatly affect the overall slicing quality

[0008] There are no special equipment and methods at home and abroad to accurately deal with the problem of end face slope and unevenness. Foreign countries use internal circular cutting machines or precision band saws for cutting processing, but they do not deliberately aim at improving end face verticality, etc. Ways to Improve Slicing Yield

With the rapid development of the silicon wafer manufacturing process, the thickness of the silicon wafer currently accepted by the market is less than 220 microns, while the domestic cutting machine usually causes a slope of more than 500 microns during the segmentation process. And the loss of silicon wafers caused by it is also increasing

The existence of the slope of the end face makes the slope "climbing" or debris during the slicing process unavoidable, which disturbs the entire wire network and affects the slicing quality

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