Photovoltaic Welding Processing

Key manufacturing process points

Photovoltaic Welding Processing covers key steps such as single-cell welding, series welding, laminating, and lamination. Each step requires strict control of parameters to ensure quality:

Single-cell welding: Use a constant-temperature soldering iron to precisely weld the tin-plated solder strip to the main grid lines of the solar cell. The soldering iron head temperature is strictly controlled within 260-280°C, and the welding time is limited to within 3 seconds to avoid damage to the solar cell due to high temperature;

Series welding stage: Connect multiple solar cells in reverse series using solder strips. The spacing error of the cells is controlled within ±0.5mm, and the flatness of the solder strips directly affects the current transmission efficiency;

Laminating process: Layer the materials in the order of tempered glass, EVA adhesive film, solar cell series, and backsheet (TPT). After laminating, an EL test is conducted to completely eliminate defects such as micro cracks and incomplete soldering;

Lamination stage: Use a high-temperature and high-pressure process to melt and solidify the EVA adhesive film, forming a sealed structure. The temperature and vacuuming time need to be precisely adjusted according to the type of EVA to ensure the sealing performance. 

Installation and Connection Specifications

After the photovoltaic welding processing, the installation and connection of the components must strictly follow the standard specifications to ensure the stable operation of the system:

1. Railing fixation: For outdoor installation, hot-dip galvanized steel or aluminum alloy rails are required. They should be fixed using bolts or clamps, with an installation flatness error of ≤ 2mm and a diagonal deviation of < 4mm;

2. Component connection: MC4 photovoltaic connectors are used for inter-component connection. When inserting the positive and negative terminals, a "click" sound should be heard to confirm the tightness. The cable bending radius should be no less than 48mm to avoid insulation aging due to direct sunlight exposure;

3. Junction box welding: Before welding the bypass diode and the welding tape, infrared preheating is required. The preheating temperature should be controlled at 120-150℃, the soldering iron temperature should be reduced to 240-260℃, and the welding time should be shortened to within 2 seconds to prevent thermal damage to the diode;

4. Finished product inspection: After welding, conduct conduction and low resistance tests to ensure the connection resistance is < 0.5mΩ. At the same time, use X-ray imaging to check the internal void rate of the solder joints, comprehensively ensuring the welding quality. 

Q&A

1. Question: During the Photovoltaic Welding Processing, high temperatures can easily damage the battery cells. How to avoid this?

Answer: This can be achieved by precisely controlling the process parameters. The temperature of the soldering iron for single cells is limited to 260-280℃ and the time is no more than 3 seconds. The temperature of the soldering iron for the connection box is reduced to 240-260℃ and the time is no more than 2 seconds. At the same time, professional temperature control equipment is used for real-time monitoring to avoid local overheating.

2. Question: What should be done if the connection resistance of the welded components is too high?

Answer: First, check the adhesion of the soldering tape to the main grid lines of the battery to ensure there is no false soldering. Secondly, optimize the welding temperature and time parameters to ensure that the soldering tape and the battery are fully integrated. Finally, strictly perform low-resistance testing after welding and promptly rework the不合格 products.

3. Question： The welding areas of outdoor-installed photovoltaic components are prone to aging. How to ensure durability?

Answer： The supports are made of hot-dip galvanized steel or aluminum alloy to enhance the anti-corrosion ability. The cables avoid direct sunlight and ensure sufficient bending radius. The connection box is well sealed. From both material and installation details， the welding areas are ensured to be stable for a long time.

4. Question： How to adjust the parameters during the lamination stage for different types of EVA adhesive films?

Answer： The lamination temperature and vacuuming time need to be precisely adjusted according to the melting point and melt index of the EVA adhesive film to ensure that the EVA adhesive film is fully melted and solidified， forming a tight sealing structure. Specific parameters can be customized by the professional technical team based on the model of the adhesive film.

Shenghui Metal takes "precise craftsmanship and stable quality" as its core competitiveness. With years of accumulated experience in photovoltaic welding processing, it has provided stable and reliable processing services for multiple photovoltaic energy projects, and has gained a good reputation in the industry. We can precisely customize welding processes according to the specifications and material requirements of photovoltaic modules, and support the entire process from small batch prototyping to large-scale production. We provide detailed Price Lists and Quotations for support. We are one of the trusted Photovoltaic Welding Processing Brands worldwide, continuously delivering reliable Made in China processing results.