Solar panel system assembly process:
Packaging
The assembly line is also called the packaging line. Packaging is a key step in the production of solar cells. Without a good packaging process, no matter how good the battery is, it will not produce a good assembly board. Battery packaging not only ensures the life of the battery, but also enhances the battery's resistance. The high quality and long life of the product are the key to winning customer satisfaction, so the packaging quality of the assembly board is very important.
Process
1. Battery detection-2. Front welding-inspection-3. Back series connection-inspection-4. Laying (glass cleaning, material cutting, glass pretreatment, laying)-5. Lamination-6. Deburring (deburring, cleaning)-7. Frame installation (glue coating, corner key installation, punching, framing, scrubbing excess glue)-8. Welding junction box-9. High voltage test-10. Component test-appearance inspection-11. Packaging and warehousing
Quality assurance skills
1. High conversion efficiency, high-quality battery cells.
2. High-quality raw materials, such as: EVA with high cross-linking degree, encapsulant with high bonding strength (neutral silicone resin glue), tempered glass with high light transmittance and high strength, etc.
3. Reasonable encapsulation process.
4. Employees' rigorous work style (Since solar cells are high-tech products, some details in the production process, some inconspicuous problems such as not wearing gloves when they should be worn, and sloppy work when the reagents should be evenly applied, are the enemies that affect product quality. Therefore, in addition to formulating a reasonable production process, the seriousness and rigor of employees are very important).
Battery testing
Due to the randomness of the production conditions of the battery cells, the performance of the batteries produced is not the same. Therefore, in order to effectively combine batteries with consistent or similar performance, they should be classified according to their performance parameters; battery testing is to classify them by testing the size of the output parameters (current and voltage) of the battery. In order to improve the utilization rate of the battery and make battery components of qualified quality.
Front welding
It is to weld the busbar to the main grid line on the front (negative) of the battery. The busbar is a tinned copper strip. The welding machine we use can spot weld the strip to the main grid line in the form of multiple points. The heat source for welding is an infrared lamp (using the thermal effect of infrared rays). The length of the welding strip is about twice the length of the battery side. The extra welding strip is connected to the back electrode of the rear battery cell when welding on the back.
Back series connection
Back welding is to connect 36 batteries in series to form a component string. The process used is manual. The positioning of the battery mainly depends on a film mold plate with 36 grooves for placing battery cells. The size of the groove corresponds to the size of the battery. The position of the groove has been designed. Different specifications of components use different templates. The operator uses an electric soldering iron and solder wire to weld the front electrode (negative electrode) of the "front battery" to the back electrode (positive electrode) of the "rear battery". In this way, the 36 pieces are connected in series in turn and the leads are welded on the positive and negative electrodes of the component string.
Lamination and laying
After the back is connected in series and passed the inspection, the component string, glass and cut EVA, glass fiber, and backplane are laid in a certain layer and prepared for lamination. A layer of reagent (primer) is applied to the glass in advance to increase the bonding strength between the glass and EVA. When laying, ensure the relative position of the battery string and materials such as glass, adjust the distance between the batteries, and lay a good foundation for lamination. (Laying layers: from bottom to top: tempered glass, EVA, battery cell, EVA, glass fiber, backplane).
Component lamination
Put the laid battery into the laminator, vacuum the air in the component, and then heat the EVA to melt and bond the battery, glass and backplane together; finally cool and take out the component. The lamination process is a key step in component production. The lamination temperature and lamination time are determined by the properties of EVA. When we use fast-curing EVA, the lamination cycle time is about 25 minutes. The curing temperature is 150℃.
Trimming
During lamination, EVA melts and solidifies due to pressure, forming burrs, so it should be cut off after lamination.
Framing
Similar to putting a mirror frame on glass; putting an aluminum frame on the glass component increases the strength of the component, further seals the battery component, and extends the service life of the battery. The gap between the frame and the glass component is filled with silicone resin. The frames are connected with angle keys.
Welding junction box
Weld a box at the lead on the back of the component to facilitate the connection between the battery and other devices or batteries.
High voltage test
High voltage test refers to applying a certain voltage between the component frame and the electrode lead to test the pressure resistance and insulation strength of the component to ensure that the component is not damaged under harsh natural conditions (lightning strikes, etc.).
Component test
The purpose of the test is to calibrate the output power of the battery, test its output characteristics, and determine the quality level of the component. It mainly simulates the test Standard test condition (STC) of sunlight. Generally, the test time required for a solar panel is about 7-8 seconds.
