The core power of reducing cost and increasing efficiency of crystalline silicon solar cells is technological progress rather than sacing product quality.According to the data of cell cost composition of China Photovoltaic Industry Association: silicon wafer cost accounts for 65%, non-silicon cost accounts for 35%, and metal chemical process accounts for more than 20% in the cell cost, so the research and development of new technologies to promote metalization progress is crucial for non-silicon cost reduction.
Metal chemical process usually USES screen printing equipment to print paste on the surface of the battery to form a circuit and electrode, screen plate, paste and printing sintering are the three key technologies.Although the direct cost reduction effect brought by the advancement of screen technology is not significant, it indirectly reduces the equipment depreciation, pulp consumption and labor costs of single watt batteries.At present, the mainstream screen plate processing is the use of exposure method, the production of electrode patterns on photosensitive materials;Dazu photovoltaic equipment innovatively introduces laser cutting method to process electrode pattern.
Traditional exposure method VS laser cutting method
Laser cutting is a revolutionary screen processing technology, for the industry to reduce cost and increase efficiency.Compared with the traditional exposure screen process, laser cutting screen has the following advantages:
● Screen life: using PI material instead of photosensitive material to make screen, better friction resistance, and advanced two printing technology, screen life can be more than 2 times, directly reduce the cost of screen allocation of a single battery;In addition, the screen plate replacement frequency to reduce the production capacity of the screen printing process and reduce the loss of silver paste, further reduce the non-silicon cost;
● More environmentally friendly process: laser treatment belongs to physical processing, no chemical developer, no waste liquid emissions, more environmentally friendly, greatly improve the working environment of employees;
● Change of pattern: draw electrode pattern directly in laser marking software, which saves the step of making exposure film, changes quickly, and facilitates to provide customized development plan for customers;
● Processing precision and quality: greatly improve the yield, in addition, laser processing can obtain excellent opening taper, finer grid line width, optimize the aspect ratio of the printed electrode, so as to further reduce the silver paste consumption.
By comparing the two technologies, it can be seen that laser cutting technology not only simplifies the process flow and improves the working environment, but also promotes the development of the industry with lower cost and higher efficiency.
Solar screen thin film laser cutting equipment
Before laser cutting screen, need to paste PI film on the screen surface.PI film screen plate processing technology is the specific wavelength of laser beam focused on PI film, the use of laser thermal effect of PI film and the corresponding rubber layer melting and vaporization, to form a specific figure.Solar screen film laser cutting equipment can be 7*24 hours of long-term stable operation, compatible with different sizes of screen, has a high-precision CCD positioning system + high-precision XY linear motor platform configuration, reduce precision error.The total processing time of a 160mm*160mm PI screen plate processed by the equipment is ≤15 minutes, and the processing efficiency is greatly improved compared with the traditional process.In the processing process, the steel mesh no damage, processing edge no burr, no residual glue;The taper and line range were controlled within 5 m, the line width was adjustable, the yield was more than 99%.