In the manufacturing of solar panels, busbar welding is a crucial process for connecting individual solar cells and constructing current transmission channels, directly determining the power generation efficiency, reliability, and lifespan of the panel. As a core link in the photovoltaic industry chain, the precision of this process is a vital support for the development of photovoltaic technology towards higher efficiency and lighter weight.
The core value of busbar welding lies in achieving efficient current convergence and low-loss transmission. The output current of a single solar cell is limited, requiring busbars to connect several cells in series or parallel to form a battery string with actual power supply capability. The quality of welding directly affects the contact resistance: high-quality welding ensures that the contact resistance approaches the ideal value, minimizing heat loss during current transmission; however, defects such as incomplete or false welds will drastically increase the contact resistance, not only reducing power generation efficiency but also potentially causing safety hazards due to localized overheating.
Achieving high-quality busbar welding requires precise control of multiple technical aspects. In terms of welding material selection, it is necessary to match the electrode material of the solar cells. Commonly used copper-based busbars require surface tin-plating or silver-plating to improve welding compatibility and enhance oxidation resistance, ensuring long-term service stability. Regarding welding processes, the current mainstream methods are infrared welding and laser welding: Infrared welding uses thermal radiation to uniformly heat the welding area, suitable for large-scale mass production, and effectively avoids microcracks caused by localized overheating of the solar cells; laser welding, with its advantages of high energy density and high precision, can achieve narrow weld seams, adapting to the production needs of ultra-thin, high-efficiency solar cells and reducing mechanical damage to the solar cells.
Quality control during the welding process is equally indispensable. Before welding, the surfaces of the solar cell electrodes and busbars must be rigorously cleaned to remove oil, oxide layers, and other impurities, ensuring a good bond at the welding interface; during welding, parameters such as temperature and pressure must be monitored in real time to avoid welding defects caused by parameter fluctuations; after welding, visual inspection, tensile testing, and resistance testing are required to screen out unqualified products, ensuring the welding quality of each solar panel.
As the photovoltaic industry moves towards higher efficiency and grid parity, busbar welding technology is also continuously being upgraded. From traditional manual welding to the widespread adoption of automated welding equipment, and from conventional welding processes to the application of high-precision laser welding technology, each technological innovation has driven improvements in solar panel performance. In the future, with the integration of new materials and intelligent welding technologies, busbar welding will become more precise, efficient, and reliable, providing a stronger technological guarantee for the sustainable development of the global photovoltaic industry.
