Manufacturing process of solar cell modules

Component wiring, also known as encapsulation wiring, is a crucial step in solar cell production. Without good encapsulation technology, even the best cells cannot produce high-quality component panels. Cell encapsulation not only guarantees the lifespan of the cell but also enhances its resistance to impact. High-quality and long-lasting products are key to satisfying customers, making the quality of component panel encapsulation extremely important.

Process:

1. Cell testing

2. Front-side welding-inspection

3. Back-side connection-inspection

4. Laying (glass cleaning, material cutting, glass pre-processing, laying)

5. Laminating

6. Deburring (edge removal, cleaning)

7. Frame installation (glue application, installation of corner keys, punching, frame installation, wiping off excess glue)

8. Welding junction box

9. High-voltage testing

10. Component testing-appearance inspection

11. Packaging and warehousing

How to ensure the efficiency and longevity of solar components:

1.High conversion efficiency and high-quality cells.

2.High-quality raw materials such as high cross-linking EVA, high bonding strength encapsulants (neutral silicone resin adhesive), high transparency and high-strength tempered glass, etc.

3.Reasonable encapsulation process.

4.Diligent work ethic of employees.

As solar cells are high-tech products, some minor issues during production such as not wearing gloves when they should or unevenly applying reagents can affect product quality. Therefore, besides developing a reasonable production process, employee diligence and rigor are essential.

Solar cell assembly process overview:

Process overview: Here we will briefly introduce the role of the process to give you a perceptive understanding.

1.Cell testing: Due to the randomness of cell production conditions, the performance of produced cells is not consistent. Therefore, to effectively combine cells with consistent or similar performances, they should be classified according to their performance parameters. Cell testing is to classify cells based on the size of their output parameters (current and voltage). This improves cell utilization and produces qualified battery modules.

2.Front-side welding: The busbar is welded onto the main grid line of the cell's positive side (negative electrode) by a welder that can spot weld the tab to the main grid line in a multipoint fashion. An infrared lamp is used as a heat source for the welding. The length of the welding strip is about twice the length of the cell. The excess welding strip connects to the back electrode of the next cell when welding to the backside.

3.Back-side connection: Backside welding is to connect 36 cells in series to form a module string. We currently use manual processes, mainly relying on a jig board with 36 slots for placing cells. The size of the slot corresponds to the size of the cell. The position of the slot has been designed, different specifications of modules use different templates. Operators use electric soldering iron and tin wire to weld the positive electrode (negative electrode) of the "front cell" to the back electrode (positive electrode) of the "rear cell," thereby connecting 36 cells in series and welding out leads on the positive and negative poles of the module string.

4.Laying and laminating: After passing the backside connection inspection, the module string, glass, cut EVA, glass fiber, and back panel are laid in a certain order, ready for lamination. A layer of primer is applied to the glass in advance to increase the adhesion strength of the glass and EVA. During laying, ensure the relative positions of the cell string and materials such as glass, adjust the distance between cells, and lay the foundation for lamination. (The laying sequence from bottom to top is: glass, EVA, cells, EVA, glass fiber, back panel).

5.Component lamination: Place the laid cells into a laminator, extract the air inside the module through vacuum pumping, and then heat it to melt the EVA to bond the cells, glass, and back panel together. Finally, cool and remove the module. Lamination technology is a critical step in module production, and the lamination temperature and time are determined by the properties of the EVA. When using fast-curing EVA, the laminating cycle time is about 25 minutes. The curing temperature is 150℃.

6.Edge trimming: During lamination, the melted EVA extends outward due to pressure, forming burrs. After lamination, they should be cut off.

7.Frame installation: Similar to framing a picture, an aluminum frame is installed around the glass component to increase its strength, further seal the cell module, and extend the cell's lifespan. The gap between the frame and the glass component is filled with neutral silicone resin. The frames are connected by corner keys.

8.Welding junction box: A box is welded at the lead wire position on the backside of the module to facilitate the connection of multiple modules in series or parallel, allowing the generated electrical energy to be outputted externally. The junction box is welded using a special welding machine, and the box should meet IP65 waterproof requirements.

9.High-voltage testing: The high-voltage testing process is to check whether each component has a qualified insulation performance and to ensure that there is no leakage current. This test is performed after the junction box is welded and before packaging.

10.Component testing-appearance inspection: This step involves checking the appearance of the components for any abnormalities, such as scratches, breakage, deformation, and other defects. Simultaneously, the electrical properties of the components are tested, including open-circuit voltage, short-circuit current, maximum power, etc. Qualified products are then classified and packaged.

11.Packaging and warehousing: After passing the appearance and electrical performance inspections, qualified components are packaged, and the package size and quantity depend on customer requirements. Different specifications of packaging materials are used according to customer requirements. Finally, the components are stored in a dry and ventilated warehouse.

In summary, the solar cell assembly process is complex, involving multiple steps that require careful handling and attention to detail. Encapsulation technology is crucial for producing high-quality solar components that are efficient and long-lasting. Through the use of quality raw materials, reasonable manufacturing processes, and diligent work ethics of employees, manufacturers can produce high-quality solar components that will satisfy their customers' needs.