Net plate used for testing sheet resistance after wet etching operation

Abstract

The invention discloses a net plate used for testing sheet resistance after wet etching operation. The net plate is characterized in that a plurality of hollow parts are formed in the front surface (namely, main grid lines) of a battery piece and are coated with photosensitive resists, therefore wax cannot permeate the net plate, and five to nine hollow parts are symmetrically distributed in the front surface and are arranged on grid lines or off the grid lines; the hollow parts are round, quadrilateral or elliptical in shape; and the size of each hollow part is (5-15)mm*(5-15)mm. The beneficial effects of the net plate are that by forming a plurality of the hollow parts in the main grid lines and coating the hollow parts with the photosensitive resists, sheet resistance after wet etching operation can be accurately tested.

Description

technical field [0001] The invention relates to the field of preparation of crystalline silicon solar cells, in particular to a screen used for testing square resistance after wet etching. Background technique [0002] In the selective emitter (SE) preparation process of crystalline silicon solar cells, it is necessary to test the square resistance of the silicon wafer after the wet etching (SPH) process. At present, there are two main methods to test the square resistance after SPH: one is to measure the square resistance after SPH treatment with the cells sprayed with wax, because when the cells pass through SPH, the wax is washed off and the mark is not clear At the same time, in order to improve the efficiency of the cell, the number of grid lines is increasing. When testing the square resistance between the grid lines, the probe cannot be accurately placed between the grid lines, resulting in inaccurate measured square resistance; the second is Directly perform SPH tre...

AI Technical Summary

Problems solved by technology

At present, there are two main methods to test the square resistance after SPH: one is to measure the square resistance after SPH treatment with the cells sprayed with wax, because when the cells pass through SPH, the wax is washed off and the mark is not clear At the same time, in order to improve the efficiency of the cell, the number of grid lines is increasing. When testing the square resistance between the grid lines, the probe cannot be accurately placed between the grid lines, resulting in inaccurate measured square resistance; the second is Directly perform SPH treatment on the diffused silicon wafer without wax spraying, and then conduct the square resistance test. The square resistance tested in this way is different from the square resistance of the wax-sprayed cell, and the SPH cannot be accurately tested. Rear square resistance

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