Photovoltaic module processing technology is an important part of the solar photovoltaic industry chain. By encapsulating thin solar cells, they can operate reliably in harsh outdoor environments.
The current mainstream photovoltaic module processing technology adopts the packaging form of EVA film packaging, and each process is interlinked. Therefore, the level of technology in each process directly affects the quality and grade of the product.
1. Solar cell inspection
As the main raw material in the processing of photovoltaic modules - the performance of cells directly determines the quality of photovoltaic modules.
Therefore, in addition to testing its appearance, color difference and resistivity, it is also necessary to test parameters such as output current, output voltage and stable durability of solar cells under specific lighting and temperature conditions. Its testing is mainly completed by professional instruments and equipment.
2. Solar cell monolithic welding
When welding, squeeze about 1/3 of one end of the welding tape with your left hand, place the welding tape flat on the main grid line of the battery, and touch the other end of the welding tape to the grid line on the battery; Hold the soldering iron in your right hand and gently press weld along the welding belt from left to right.
When soldering, the starting point of the soldering iron tip should be on the left side of the single chip, and the flat surface of the soldering iron tip should always be close to the soldering tape. Welding should be firm, free of burrs, virtual welding and tin slag, and the surface should be smooth and beautiful.
3. String welding of solar cells
The operation process is as follows: Arrange the specified number of welded cells on the template with the back facing upward, and lightly press the two cells with one hand to make them stick to the heating template and close to each other.
According to the specified distance (2±0.5 mm), the solder bar drawn from the latter cell is pressure-welded to the back electrode of the former solar cell with a soldering iron. When welding, it is required that the solder bar is welded flat, the appearance is straight, there is no protruding solder bumps, and there is no virtual welding phenomenon.
4. Lamination of solar photovoltaic modules
Lift the tempered glass to the workbench, with the velvet surface of the tempered glass facing up, lay a layer of EVA on the tempered glass, and the margin of EVA on the four sides of the tempered glass is ≥5mm;
Note that the smooth surface of the EVA should face the tempered glass suede, and a positioning template that conforms to the panel type of the solar photovoltaic module should be placed on the EVA. The battery strings correspond to the head and tail templates respectively.
According to the positive and negative symbols marked on the template, correctly place the battery string on the EVA, with the anti-reflection film of the battery string facing down. After the battery string is in place, measure the distance of the battery with a steel ruler and adjust the position of the battery string according to the requirements of the drawing and the positioning template.
According to the component splicing diagram and voltage requirements, solder the busbar correctly, and paste the barcode on the specified position. Lay the EVA with its suede facing the battery string, and then lay the TPT. Carry out EL test to confirm that there are no defects such as cracks, virtual soldering, desoldering, and black flakes.
5. Lamination of solar photovoltaic modules
Start the laminator according to the operating procedures of the laminator, adjust the lamination temperature and evacuation time according to the characteristics of EVA, and record the technical parameters such as temperature and pressure on the operation record sheet;
Put a layer of high temperature non-stick cloth on the heating plate in the laminator, put the spliced solar photovoltaic module tempered glass face down into the middle of the heating plate of the laminator, then put a layer of high temperature non-stick cloth, press and close the cover button, the laminator enters the automatic control system.
When the lamination is over, the laminating machine automatically opens the cover and takes out the processed components in time. The chips in the module are required to be free of foreign objects, fragments, cracks, etc.
6. Frame of solar photovoltaic modules
Put silica gel evenly in the groove of the aluminum alloy frame, embed the components into the groove of the aluminum alloy, and start the frame assembling machine to complete the framing. Apply silicone evenly at the junction of TPT and aluminum alloy on the back of the module.
On the back of the junction box of the corresponding specification and the root of the lead wire, evenly apply silica gel around it, glue the junction box, connect the lead wire to the junction box, and cure at room temperature and a certain humidity.
7. The cleaning of solar photovoltaic module
Tear off the plastic film on the surface of the aluminum profile, and use alcohol to clean the various contaminants on the surface of the component to ensure that the component looks clean and free of contamination.
8. Testing of finished solar photovoltaic modules
To test in accordance with the operating procedures of the photovoltaic module tester, first calibrate the solar module tester with standard components in the same environment.
And make calibration records, put in the photovoltaic modules to be tested, connect the positive and negative poles, test the solar photovoltaic modules, calculate and record the electrical performance parameters of the modules through comparison and analysis.