A method for etching extremely-thin electrical isolation grooves on the surface of an ITO conductive thin film

Abstract

The invention provides a method for etching extremely-thin electrical isolation grooves on the surface of an ITO conductive thin film. The method is characterized in that, to begin with, sputtering metal chromium on the reverse side of an ITO conductive thin film glass substrate; fixing the ITO conductive thin film glass substrate on an object bearing table, with the side having the metal chromium being on the side of laser emission area and keeping the area needing etching on one side of the ITO conductive thin film not to be contacted with the object bearing table; and at last, utilizing picoseconds laser to etch ITO conductive thin film backwardly, wherein the center line of the picoseconds laser beam must keep perpendicular to the surface of the ITO conductive thin film and the focal position of the picoseconds laser must be on the ITO conductive thin film in the whole processing process. The method in the invention effectively reduces the width of the grooves in the surface of the ITO conductive thin film in a thin-film solar cell, guarantees processing efficiency of the picoseconds laser, and improves the overall level of the thin-film solar cell manufacture.

Description

Technical field [0001] The invention belongs to the field of micro-manufacturing technology, and specifically relates to a method for etching extremely fine electrical isolation grooves on the surface of an ITO conductive film. Background technique [0002] At present, thin film technology is applied to the field of new solar cell manufacturing, successfully solving the high cost problem of crystalline silicon solar cells. Due to the high light transmittance in the visible light region and good conductivity, the ITO conductive film with electrical isolation grooves on the surface is widely used as the front surface electrode of thin film solar cells. In the manufacturing process of thin-film solar cells, it is usually necessary to cut the whole ITO film into several units by textured electrical isolation grooves, and through the structural design, a series structure is formed between each unit to achieve the best voltage and current ratio. The size and accuracy level of the elec...

AI Technical Summary

Problems solved by technology

Since the nanosecond pulse width is much longer than the thermal diffusion time of the material, during the ablation removal process of the material, it is affected by heat conduction, causing serious thermal impact and thermal damage to the edge state of the active area

When processing nanosecond laser ablation processing with a thin-film solar cell groove structure, there are many problems, such as protrusions on the edge of the processed micro-groove, shunt or short circuit from the local to the upper layer; Micro-cracks and local material peeling, thereby shortening the service life of solar cells; when the laser pulse superposition rate is too high, due to the accumulation of thermal effects, the substrate glass may be melted and the barrier may be destroyed. The above problems seriously hinder many Normal commercial production and use of thin-film solar cells

The processing quality and efficiency of mechanical scribing are worse than those of nanosecond laser processing. It is difficult to engrave a micro-groove width below 50 μm. Low

The above-mentioned problems of nanosecond laser ablation and mechanical scribing processing make it difficult to manufacture thin-film solar cells with high efficiency and high precision, and have become a technical bottleneck that seriously hinders the development of such solar cells.

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