Screen printing involves printing the first layer of battery cells - back electrode paste - silver aluminum paste, the second layer of back electric field - aluminum paste and the third layer of positive electrode - paste silver. The basic principle of the screen. printing involves scratching. The bar extrusion screen will flow the paste onto the material to be printed (silicon wafer). The main thing is to stand there and watch to see if any faulty films are passing through the machine. I used to work at Zhongsheng Optoelectronics for one. while. The first class.
What are the process problems encountered in solar cell screen printing and their solutions?
The wire mesh employees of the photovoltaic solar cell factory are doing a good job. The work in the photovoltaic factory is not tiring and it is not physical work. As long as you are brave and careful, you can basically start in half a month. The equipment has a low voltage level and is reliable. There are few workers for maintenance and operation, and the responsibilities are not as great as those in thermal, hydroelectric and nuclear power. generally sparsely populated and isolated. There are many photovoltaic installations and there are few problems after installation.
Why do solar cells have thin grid lines?
1. Warp:\x0d\1. The silicon wafer is too thin - check the thickness of the original silicon wafer\x0d\2. Printing The aluminum paste is too thick - check the weight of the aluminum paste\x0d\3 The sintering temperature is too high - adjust the temperatures in zones 4, 5, 6 and 7 of the sintering furnace\x0d \4. The effect in the cooling zone of the sintering furnace is not good - check the fan condition, temperature and pressure.n of inlet and outlet water, etc. \x0d\ 2. Aluminum packaging: \x0d\ 1. The sintering temperature is too high - adjust the temperature in zones 4, 5, 6 and 7 of the sintering furnace \x0d\ 2. The printed aluminum paste is too thin - The weight of the printed aluminum paste increases\x0d\3 The slurry is not stirred sufficiently before use - the. the stirring time should reach the specified time\x0d\4. The drying time after printing the aluminum paste is not enough - increase the drying time or increase the drying temperature\x0d\ x0d\5. Exhaust air from the sintering furnace\x0d\6. The cooling effect in the sintering furnace cooling zone is not good - check the fan condition, inlet and outlet water temperature and pressure, etc.\x0d\ 3. False impression:\x0d\1. Print pressure is too low - increase print pressure\x0d\2. Spacing between printing platesion is too large - reduce the spacing between the plates\x0d\3. scraper strip\x0d\4. Work The tabletop is uneven and badly worn - replace the worktable\x0d\5 The screen printing guide rails are uneven - readjust the guide rails\x0d\ 4. Thick lines: \x0d\1. . The screen plate has been used too many times and the voltage is not enough - —Replace screen version\x0d\2. Screen version settings are not qualified. Check the screen settings of this batch and replace the screen version\x0d\3. . The mud is too fine and the mud mixing time is too long. Strictly enforce regulations on mud mixing time\x0d\4. The screen printer settings are inappropriate.x0d\\x0d\It is recommended to learn on the actual production line.
Because of the screen printing.
Once the solar cell has undergone processes such as texturing, diffusion and PECVD, ithas been transformed into a PN junction, which can generate current under light. In order to conduct the generated current, this is necessary. to make positive and negative junctions on the surface of the battery electrode. There are many ways to manufacture electrodes, and screen printing is currently the most common production process for manufacturing solar cell electrodes.
For solar cells, in order to obtain the highest possible photoelectric conversion efficiency, the cell structure must be designed in detail. The metal grid is responsible for guiding the photocurrent inside the battery to the outside of the battery. Optimal design of solar cell arrays relies on minimizing total battery power loss.
A well-designed grid structure will minimize the series resistance of the battery, thereby minimizing power loss and maximizing power.output power. This is especially important for single solar cells with large area power output.
Reducing the width of the fine grid lines during the process can reduce the required optimal spacing of the fine grid lines, which can significantly reduce the total relative power loss of the side current of the upper layer and the relative power of the fine lines. shading losses of the grid line, thereby reducing the total power loss caused by the electrode. In order to increase the resistance of the sheet and reduce the power loss caused by the electrode, it is necessary to increase the number of fine grid lines and reduce the width of the fine grid lines.
Detailed Information
Screen printing uses printing to print predetermined graphics onto the substrate. The equipment is printed with silver aluminum paste tothe back of the battery. , consisting of three parts: aluminum paste printing on the back of the battery and silver paste printing on the front of the battery. Its working principle is as follows:
Use the mesh of the sieve pattern to penetrate the slurry, apply some pressure to the slurry sieve part with a scraper, and move to the other end of the sieve at the end. at the same time. The ink is expelled by the scraper from the mesh of the graphic part onto the substrate during movement. Due to the viscosity of the paste, the impression is fixed within a certain range. When printing, the scraper is always in linear contact with the screen printing plate and the substrate. The contact line moves with the movement of the scraper, completing the movement. printing stroke.
Baidu Encyclopedia-Solar Cells