Edge cleaning method of ultraviolet laser thin-film solar battery

Abstract

The invention discloses an edge cleaning method of an ultraviolet laser thin-film solar battery, belonging to the field of laser processing. The invention has the key characteristics that: ultraviolet laser with quite high absorption rate of transparent conductive film is introduced to the edge cleaning application of a thin-film solar battery, and in contrast to the laser power adopted by infrared laser edge cleaning, the method can complete high quality laser edge cleaning efficiently with smaller ultraviolet power, besides, the edge cleaning method has low possibility of damaging glass, extremely strong compatibility with different types of transparent conductive films and reduced using cost.

Description

[0001] Technical field The present invention belongs to the field of laser processing, especially the field of edge cleaning of laser thin film solar cells. Background technique [0002] At present, the development of thin-film solar energy is in the ascendant. The last process of thin-film solar glass substrate battery is to hermetically encapsulate the glass substrate. In order to prevent battery short circuit and better airtight packaging, the thin film (positive and negative The electrode film and the active layer film) need to be cleaned, which is called edge cleaning or edge sweeping in the industry. The earliest method of sandblasting is low cost, but the environmental pollution is serious, so it is gradually eliminated. [0003] Using a laser to directly vaporize the surrounding area of ​​the battery glass through the glass is a relatively popular method at present. In order to meet the production rhythm of one piece of glass per minute, the industry usually uses a high...

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Problems solved by technology

[0005] We can think that during the laser edge cleaning process, the solar film is directly vaporized under the action of the laser. The total thickness of these films does not exceed 5 microns, and the total thickness of the solar film of most batteries does not even exceed 2 microns. The energy required can be determined according to the relevant The heat of vaporization of the material is calculated, but it is certain that most of the energy is not absorbed and wasted directly when a high-power infrared laser of 200W to 500W is used for laser edge cleaning.

This is because the conductive film of thin-film solar cells is transparent to visible light and has a certain transmittance to infrared light. Obviously, using infrared laser for laser edge cleaning is not a reasonable laser edge cleaning solution.

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