The photovoltaic module processing is an important part of the solar photovoltaic industry chain, which can operate reliably in harsh outdoor environments by encapsulating thin solar cells.
At present, the packaging form used in the processing technology of mainstream photovoltaic modules is EVA; film packaging, which is composed of multiple processes such as cell detection, cell single welding, cell string welding,module cascade，module lamination, mounting frame and installation junction box, finished product testing and packaging storage. Each process is interlocked, so the level of process of each process directly affects the quality and grade of the product.
The first step is cell detection. As the main raw material for the processing of photovoltaic modules-the performance of the cell directly determines the quality of the photovoltaic module. Therefore, in addition to its appearance, chromatic aberration and resistivity detection, but also to test the battery in a specific light, temperature conditions of the output current, output voltage and stability, durability and other parameters, its test is mainly through professional instruments and equipment to complete.
The second step is the monolithic welding of the battery. When welding, the left hand pinches the pressure welding strip at about 1/3; of the end, and places the welding strip flat on the main grid line of the cell,and the other end of the welding strip touches the grid line on the cell. Take the soldering iron in your right hand and gently press the soldering belt evenly from left to right. When welding, the starting point of the soldering iron tip should be on the left side of the single piece, and the plane of the soldering iron tip should always be close to the welding belt. Welding should be firm, no burrs, no virtual welding and tin slag, the surface is smooth and beautiful.
The third step is the string welding of the cell. The operation process is: the specified number of welded cells, the back of the back up on the template, with one hand to gently press the two cells, so that they are attached to the heating template, close to each other, in accordance with the specified spacing (2士0.5 mm ). Press the solder strip from the latter cell with a soldering iron on the back electrode of the previous cell. When welding, the solder strip is required to be welded smoothly, the appearance is straight, there is no convex solder lump, and also no virtual welding phenomenon.
The fourth step is cascading. Lift the tempered glass to the laminated workbench with the suede of the tempered glass facing upwards and lay a layer of EVA on top of the tempered glass. The margin of EVA on the four sides of tempered glass ≥5mm. Pay attention to the smooth side of the EVA facing the tempered glass suede, put the positioning template in line with the component plate type on the EVA, the battery string corresponds to the head and tail templates, and the battery string is correctly placed according to the positive and negative symbols identified on the template on the EVA, the anti-reflective film of the battery string faces down.
After the battery string is placed in place, according to the requirements of the pattern and the positioning template, the distance of the battery is measured with a steel plate ruler, and the position of the battery string is adjusted. According to the assembly splicing diagram and voltage requirements, the busbar band is welded correctly and the bar code is pasted in the specified position. Lay the EVA, its suede facing the battery string, and then lay the TPT, conduct ANEL test to confirm that there is no hidden crack, virtual welding, desoldering, black sheet and other defects.
The fifth step is lamination. Start the laminator according to the operating procedures of the laminator equipment, adjust the lamination temperature and evacuation time according to the characteristics of EVA, and record the temperature, pressure and other technical parameters on the operation record sheetput a layer of high-temperature non-stick cloth on the heating plate in the laminator, send the spliced components tempered glass downward into the middle of the laminate heating plate, and then put a layer of high-temperature non-stick cloth, press the cover button, and the laminator enters the automatic control system. When the lamination is over, the laminator automatically opens the lid and takes out the processed components in time, requiring the chip in the components to be free of foreign matter, debris, cracks, etc.
The sixth step is framing. The aluminum alloy frame groove is evenly marked with silicone, the assembly is embedded in the aluminum gold groove, and the framer is started to complete the framing. On the back of the component TPT and aluminum alloy junction evenly coated with silicone, on the back of the corresponding specification of the junction box and the lead out of the root, around the even plastered silicone, glued to the junction box, the lead to the junction box. Curing at room temperature and humidity. Requirements: The frame installation is flat and not bent, the gap at the right angle connection of the aluminum alloy is not large to 0.2mm, and the error of the 2 diagonal lines of the aluminum alloy frame is less than 4 mm.
The seventh step is cleaning. Peel off the plastic film on the surface of the aluminum profile and wash various contaminants on the surface of the component with alcohol to ensure that the appearance of the component is clean and pollution-free.
The eighth process is the testing of the finished component. According to the solar module tester operating procedures for testing, first use the standard module in the same environment to calibrate the solar module tester, and do a calibration record, put in the photovoltaic module to be tested, connect the positive and negative poles, test the module. Through comparison and analysis, calculate the electrical performance parameters of the module, and record.
