1. Cell Testing: To ensure the quality of solar cell modules, cell testing is the first step. Due to uncertainties in cell manufacturing conditions, the performance of produced cells will vary. Therefore, classifying cells according to their performance parameters is crucial to ensure that cells with consistent or similar performance can be combined. Cell testing classifies cells by measuring their output parameters (current and voltage), thereby improving cell utilization and laying the foundation for assembling qualified solar cell modules.
2. Welding: Connecting multiple solar cells in series to form a solar cell string is a critical step in the assembly process. Traditional welding methods include spot welding and infrared welding, but now, copper flat wire plated with 60% Sn, 38% Pb, and 2% Ag is more commonly used. During welding, temperature and time need to be controlled to avoid crystal growth in the weld seam or cell breakage. Simultaneously, it is essential to ensure proper fit and gaps between weld joints, resulting in smooth, flat, and reliably strong joints.
3. Back-side Stringing: Connecting 36 cells in series to form a module string is a key step in the assembly process. The operator must use a soldering iron and solder wire to connect the positive and negative terminals of adjacent cells sequentially to form a complete module string, ensuring uniform spacing and consistent color.
4. Lamination Installation: After the back-side stringing is completed, the module string, glass, EVA, fiberglass, and backsheet are laid out in specific layers, ready for lamination. During installation, the relative positions of the cell string and other materials such as glass must be accurate to lay a solid foundation for subsequent lamination.
5. Module Lamination: The installed cells are placed in a laminator for lamination. Vacuuming and heating melt the EVA, bonding the cells, glass, and backsheet together. Temperature and time must be carefully controlled during lamination to ensure proper EVA curing. After lamination, the module must be cooled, removed, and its quality inspected.
6. Trimming and Framing: After lamination, the module needs to be trimmed to remove burrs formed by the melted EVA. Framing is then performed to increase the module's strength and further seal the solar cell module, extending its lifespan. The gap between the frame and the glass assembly is filled with silicone resin to ensure a good seal.
7. Welding Junction Box and High-Voltage Testing: A junction box is welded to the lead wires on the back of the assembly to facilitate connection between the battery and other devices or batteries. High-voltage testing is conducted to check the assembly's withstand voltage and insulation strength to ensure it is not damaged under harsh natural conditions.
8. Assembly Testing: Finally, assembly testing is performed to calibrate the battery's output power and determine its quality grade. The international IEC standard test conditions are AM1.5, 100MW/m², and 25℃. The assembly is tested under these conditions to ensure its performance meets requirements.
