What is the main function of the Photovoltaic Welding Strip Rolling Mill

      The Photovoltaic Welding Strip Rolling Mill is the core equipment for precision processing of photovoltaic ribbons. It is primarily used to roll raw brass/copper round wires into flat ribbons (also known as busbars or interconnectors) of specific thickness and width through multiple cold rolling processes. It is a key equipment in the photovoltaic module production chain, ensuring current transmission efficiency and module reliability. Its functions are mainly reflected in the following four aspects:

1.Achieve precise formation of solder ribbons to meet the connection requirements of photovoltaic cells

       Photovoltaic cell grid lines are extremely thin, requiring flat ribbons to achieve surface contact and reduce contact resistance. Through precise control of rolling pressure, roller speed, and pass distribution, the rolling mill can roll copper round wires into flat ribbons with a thickness of 0.08~0.3mm and a width of 0.8~5mm, with a tolerance controlled within ±0.005mm. This meets the welding adaptability requirements of different specifications of cells (PERC, TOPCon, HJT, etc.), while ensuring that the surface of the ribbons is smooth and burr-free, avoiding scratching the cell grid lines.

2.Enhance the conductivity and mechanical properties of the welding strip

       During the cold rolling process, the internal grains of the copper strip are refined and fiberized, which not only significantly enhances the tensile strength of the solder strip (up to over 300MPa), preventing solder strip fracture during component packaging or outdoor use; but also optimizes the conductivity of copper (the conductivity of copper strips with purity ≥99.9% can reach over 100% IACS after rolling), reducing current loss during transmission and directly improving the power generation efficiency of photovoltaic components.

3.Lay the foundation for the subsequent tin plating process

        The surface of the flat solder strip formed by rolling has a uniform roughness, which enhances the bonding force with the tin plating layer and prevents issues such as soldering defects and detachment caused by the peeling of the tin plating layer. Some high-end rolling mills also integrate online cleaning, drying, and straightening functions to remove oil stains and oxide layers from the surface of the solder strip, further improving the quality of tin plating and ensuring the corrosion resistance and soldering reliability of the solder strip.

4.Adapt to the needs of large-scale and flexible production

        Modern photovoltaic (PV) ribbon mills feature high-speed continuous rolling and rapid specification change capabilities, with rolling speeds reaching 60~120m/min, meeting the needs of large-scale mass production of PV modules. At the same time, by changing rollers and adjusting process parameters, the production of different specifications of ribbons can be quickly switched, adapting to the processing needs of new products such as HJT module low-temperature ribbons and double-sided module shaped ribbons, helping photovoltaic enterprises reduce costs and increase efficiency.