The manufacturing process of the solar cell sheet is as follows: the back electrode slurry, the backfield slurry, and the positive silver slurry (hereinafter referred to as the slurry) are printed on the silicon sheet through the screen to form the back electrode, the backfield and the main gate, by drying and sintering process made of solar cells, the assembled solar cells will generate electricity to the outside world, so that photovoltaic power generation.
In the conventional production process, the resulting rework piece is usually rework processing, you need to use a dust-free cloth dipped in terpineol for manual scrubbing. In the process of cleaning, the metal in the slurry is easy to sticks to the edge of the battery, resulting in impurities on the surface of the battery What's more, the surface of the battery is made up of a small pyramid structure. It's not easy to wipe off the slurry in the depression. To wipe off the slurry completely by hand would destroy the anti-reflection film on the surface, even destroy about 0.3 mm p-n junction, and then print the slurry in the place where the P-N junction is destroyed, it is easy to cause p-n junction leakage, low battery conversion efficiency and so on.
The ultrasonic cleaning equipment makes use of the cavitation, acceleration, and direct flow action of ultrasonic waves in the liquid to make direct or indirect action on the liquid and the dirt, which makes the dirt layer be dispersed, emulsified, and peeled off, to achieve the goal of cleaning. We use the ultrasonic cleaning machine mainly cavitation, ultrasonic pressure, and compression of more than 20,000 times per second to the interaction of high-frequency conversion of liquid transmission. When the pressure is reduced, the vacuum nuclear group bubbles are formed in the liquid; when the pressure is applied, the vacuum nuclear group bubbles are subjected to the pressure and produce a strong impact force when they are crushed, thereby stripping the dirt on the surface of the cleaned object, to achieve the goal of rapid cleaning.
Through the analysis of the reworked sheet after cleaning, it is found that the removal efficiency of the reworked sheet after ultrasonic cleaning is slightly lower and other parameters are normal, which proves that the ultrasonic cleaning equipment can be used. The ultrasonic cleaning machine can meet the needs of solar cell printing rework sheet cleaning, the cleaning effect is good, easy to operate, greatly improve the recycling rate of printed defective products, and reduce the loss of production capacity, the utility model has certain use-value.
