The production of solar photovoltaic panels involves a series of precise processes and specialized equipment. It starts with laser scribing to cut silicon wafers into cells, followed by soldering these cells into strings. The cells are then layered with materials like glass, EVA, and backsheet before being laminated under high temperature and pressure. Subsequent steps include frame assembly, junction box installation, cleaning, and rigorous testing (IV and EL) to ensure electrical performance and detect defects. Finally, the modules undergo comprehensive inspection and packaging. Each step is supported by dedicated equipment such as laser scribing machines, string soldering machines, laminators, and testing instruments. These processes and equipment work together to ensure the production of high-quality, reliable solar photovoltaic panels that meet industry standards.

Detailed Explanation of Solar Photovoltaic Panel Production Line

Process Flow and Equipment

1. Laser Scribing

• Process Content: Using laser technology to cut silicon wafers into individual solar cells. Laser scribing can precisely control the cutting path and depth, reducing microcracks in the wafers and enhancing the mechanical strength of the cells.
• Key Control Points:
• Cutting Precision: Ensure the cutting path aligns with the design to avoid deviations.
• Temperature Control: Prevent damage to the silicon wafers due to excessive heat during the laser cutting process.
• Equipment: Laser Scribing Machine.

2. Solar Cell Soldering

• Process Content: Soldering solar cells together with interconnect ribbons to form strings, creating a series electrical circuit. The quality of soldering directly affects the electrical performance and reliability of the module.
• Key Control Points:
• Cold Soldering: Ensure good electrical contact between the interconnect ribbons and the solar cells.
• Over-Soldering: Avoid damaging the solar cells due to excessive soldering temperature.
• Cell Cracking: Prevent the solar cells from breaking during the soldering process.
• Soldering Tensile Strength: The interconnect ribbons should have sufficient mechanical strength after soldering.
• Equipment: String Soldering Machine.

3. Lamination

• Process Content: Layering the soldered cell strings with glass, EVA (ethylene-vinyl acetate), and backsheet materials in a specific order. The typical layering sequence is: glass, EVA, cell strings, EVA, backsheet.
• Key Control Points:
• Material Alignment: Ensure all layers are properly aligned to avoid misalignment.
• Layering Sequence: Follow the process requirements for layering.
• Equipment: Automatic Laminating Equipment.

4. Laminating

• Process Content: Bonding the layered materials together under high temperature and pressure to form a module. During the laminating process, the EVA melts and fills the gaps between the solar cells, while firmly adhering the glass and backsheet together.
• Key Control Points:
• Laminating Temperature: Typically around 130°C.
• Laminating Time: Adjust according to the equipment and material characteristics.
• Laminating Pressure: Ensure the layers are tightly bonded.
• Equipment: Laminator.

5. Frame Assembly

• Process Content: Installing an aluminum frame to protect the edges of the module and facilitate installation. The frame is bonded to the module using silicone sealant.
• Key Control Points:
• Frame Sealing: Ensure the frame is properly sealed to the module to prevent moisture ingress.
• Installation Stability: The frame should be securely attached to the module.
• Equipment: Automatic Framing Machine.

6. Junction Box Installation

• Process Content: Installing a junction box for current output and module protection. The junction box is fixed to the back of the module through soldering or bonding.
• Key Control Points:
• Wiring Stability: Ensure the electrical connection between the junction box and the module is reliable.
• Waterproofing: The junction box should have good waterproof performance.
• Equipment: Junction Box Soldering Machine.

7. Cleaning

• Process Content: Removing dirt from the surface of the module to improve light transmittance. Cleaning is usually done with deionized water and specialized cleaning agents.
• Key Control Points:
• Cleaning Effectiveness: Ensure the module surface is free of residual dirt.
• Surface Cleanliness: The surface should be free of water marks and dust after cleaning.
• Equipment: Cleaning Equipment.

8. IV Testing

• Process Content: Testing the electrical performance parameters of the module, including open-circuit voltage, short-circuit current, and maximum power. The IV curve tester measures the output characteristics of the module.
• Key Control Points:
• Voltage: Measure the open-circuit voltage of the module.
• Current: Measure the short-circuit current of the module.
• Power Output: Calculate the maximum power of the module.
• Equipment: IV Curve Tester.

9. EL Testing

• Process Content: Using infrared imaging technology to detect internal defects in the module, such as microcracks, cold soldering, and hot spots. The EL tester uses electroluminescence principles to inspect the internal structure of the module.
• Key Control Points:
• Defect Detection Sensitivity: Ensure the ability to detect minor internal defects.
• Equipment: EL Tester.

10. Final Inspection

• Process Content: Conducting a comprehensive inspection of the module’s appearance and performance to ensure it meets quality standards.
• Key Control Points:
• Appearance Damage-Free: Check the module surface for scratches, cracks, and other damage.
• Performance Compliance: Ensure the electrical and mechanical performance of the module meets the design requirements.
• Equipment: Appearance Inspection Device.

11. Packaging

• Process Content: Packaging the finished module for storage or transportation. Packaging materials typically include moisture-proof film and cardboard boxes.
• Key Control Points:
• Packaging Stability: Ensure the module is securely packaged to prevent damage during transportation.
• Moisture Resistance: The packaging should have good moisture-proof performance.
• Equipment: Packaging Line.

Process Flow Table

Equipment Table

By providing a detailed explanation of the process flow and equipment, we can gain a comprehensive understanding of each link in the solar photovoltaic panel production line and its key control points, ensuring the production of high-quality photovoltaic modules.