Silicon-block cutting method

Abstract

The invention discloses a silicon-block cutting method, which relates to the technical field of crystalline-silicon manufacture. The method comprises the following steps of respectively preparing the usage amounts of recycled silicon carbide and a recycled suspending liquid used in mortar as 40 to 100 percent, modulating the density of the mortar as 1.625 to 1.635kg / L, and adding the mortar according to the effective cutting length of a silicon block in the cutting process, wherein the adding proportion of the added mortar is 0.235 to 0.3L / mm, and the adding amount of the mortar is equal to the effective cutting length of the silicon block multiplied by the adding proportion of the mortar; selecting a guiding wheel to enable the notch of the guiding wheel to be matched with a steel wire; setting the cutting speed of the steel wire as 12 to 14m / s, the moving speed of a worktable as 250 to 330mu m / min and the flow quantity of the mortar as 130 to 160kg / min, cutting the silicon block, and cooling; cutting a structural wire, the outer surface of which is provided with spiral bulges and is coated with an anti-oxidation layer by the steel wire. According to the invention, through the technical matching property of the cutting speed of the steel wire, the moving speed of the worktable and the flow quantity of the mortar, the updating of the mortar is reduced, the production cost can be lowered, the rate of fragments generated in silicon-block cutting is reduced, the rate of finished products is increased, and the quality of the products is improved.

Description

technical field [0001] The invention relates to the technical field of crystalline silicon production. Background technique [0002] At present, in the solar energy industry, the processing of silicon wafers refers to cutting silicon blocks into silicon wafers of a certain thickness. The cutting of silicon block is mainly driven by steel wire and mortar cutting. Mortar consists of suspension and silicon carbide. In the processing of silicon wafers, steel wires, mortar, and guide wheels are required to participate. At the same time, the high-speed rotation of the steel wires and the continuous flow of mortar on the steel wires are required to complete the cutting of silicon wafers. Specific cutting process: the steel wire with a certain tension rotates horizontally at high speed under the drive of the guide wheel, the mortar flows on the steel wire continuously, and the viscous suspension can carry silicon carbide and attach to the rotating steel wire. As the block of sili...

AI Technical Summary

Problems solved by technology

Since the surface of the steel wire is relatively smooth, the ability to carry mortar is relatively weak, and the ability of the steel wire to cut silicon wafers is poor. In order to meet the cutting effect, more mortar is needed to participate in the cutting, which leads to longer cutting time. It will increase the cost of cutting; in addition, the cutting speed of conventional steel wire, the moving speed of the worktable and the flow rate of mortar are relatively low, the work efficiency is low, and the cost is high

[0007] Diamond steel wire cuts silicon wafers, the cutting speed is relatively fast, and there are shortcomings. Since there is no matching cutting process at present, saw marks will appear on the surface of silicon wafers during the process of cutting silicon wafers, and the silicon powder after cutting is easy to remain in the cutting equipment. On the other hand, it is not easy to clean, and because of the fast cutting speed in cutting with diamond wire, the steel wire is easy to break, and the cost is high

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