Difficult Penetration of Highly Reflective Copper & Aluminum: 3 Core Processes for Laser Autogenous Welding of Power Battery Busbars
With the surging export volume of new energy vehicles, power batteries, as the core component, face stringent requirements on production capacity and quality. In battery module manufacturing, the welding of busbars and poles is a critical process that determines the conductivity, internal resistance and airtightness of battery packs.
However, many manufacturers are troubled by drawbacks of conventional welding processes. Copper and aluminum alloys feature high laser reflectivity, making full penetration hard to achieve. Traditional resistance welding and TIG welding generate heavy spatter and high heat input, which easily burn adjacent plastic insulation components. Worse still, pores tend to form inside weld seams, lowering inspection pass rates and limiting production tact time and yield. Solving the challenges of high reflectivity and porosity in copper-aluminum welding has become an essential task for new energy smart manufacturing.
Field Upgrade Record of a Leading Power Battery Manufacturer
Recently, a leading power battery maker upgraded its busbar and copper-aluminum connector welding processes to laser autogenous welding during capacity expansion. Faced with three major issues: high reflectivity of copper, high porosity rate and large thermal deformation, the manufacturer introduced Eagle Laser automatic welding machines. Combined with process optimization and equipment coordination, stable autogenous welding of highly reflective materials was realized.
Eagle Laser Solutions: 3 Core Processes to Break Bottlenecks
- High Power Density & Keyhole Effect to Overcome High Reflectivity
Copper has very low absorption rate for conventional laser beams, which often leads to cold joints in traditional processes. Eagle Laser automatic welding machines optimize beam quality and focusing systems to boost power density to 10⁶~10⁷ W/cm². Under the keyhole effect, the material surface vaporizes instantly to form a deep penetration cavity. Laser energy is repeatedly reflected and fully absorbed inside the cavity, eliminating the high-reflection barrier of copper and aluminum. Pure autogenous welding is adopted without filler wire or auxiliary materials, delivering ultra-clean welds and greatly reduced internal resistance, fully meeting strict low-resistance requirements of power batteries. - Beam Oscillation Technology to Suppress Porosity and Spatter
Copper and aluminum molten pools flow easily and are prone to pore formation. Eagle Laser equipment integrates beam oscillation technology. The laser beam oscillates along preset paths at high frequency to agitate the molten pool and extend the escape time of bubbles. This process reduces weld porosity to an extremely low level and minimizes welding spatter. Smooth weld appearance removes the need for post-weld grinding. - Precise Heat Input Control to Protect Adjacent Insulation Parts
Power battery packs have compact internal space with dense plastic insulators around busbars. Eagle Laser autogenous welding is non-contact processing with micron-level heat-affected zones. Supported by Eagle’s self-developed welding process expert system, pulse waveform and heat input are accurately controlled. Reliable metallurgical bonding is achieved while surrounding plastic parts remain free from burns and deformation, improving overall battery pack safety.
Verified On-site Performance Data
After production line upgrade, busbar welding efficiency increases 3–5 times compared with traditional processes. 100% of welds pass metallographic and airtightness tests, with stable yield above 99%. Post-weld cleaning and grinding procedures are eliminated, saving more than 40% of labor and consumable costs for each production line annually.
Eagle Laser: Industry-University-Research Integration Simplifies Welding of Highly Reflective Materials
Based in Changchun, the birthplace of China’s first laser, Eagle Laser is a high-tech enterprise leveraging industry-university-research resources from Changchun Institute of Optics, Fine Mechanics and Physics and Huazhong University of Science and Technology. It has accumulated rich expertise in welding highly reflective metals and automated system integration. Our machines feature strong anti-electromagnetic interference performance and maintain stable continuous operation in complex battery workshop environments.
Moreover, Eagle Laser is developing an integrated framework of “Laser + Automation + AI”. Services cover visual positioning, adaptive parameter optimization and robotic flexible manufacturing. We provide one-stop full-cycle support including technical consultation, solution design, installation and commissioning, helping new energy and precision manufacturers overcome technical barriers.
About Eagle Laser
Changchun Eagle Laser Equipment Co., Ltd. is a high-tech enterprise located in the Optoelectronics & Intelligent Manufacturing Industrial Park of Changchun New District. Rooted in Changchun’s robust optoelectronic industry and research institutes, we focus on R&D and manufacturing of laser welding, cutting, marking and cleaning systems. We hold 2 invention patents, plus over 20 utility model patents and software copyrights. Our products serve automotive manufacturing, precision machinery, sheet metal fabrication and other sectors, and are exported worldwide.
Tel: +86 132 3430 6142
Email: sales01@flelaser.com
Website: www.flelaser.com
Douyin: Changchun Eagle Laser Equipment Co., Ltd. (for more on-site product videos)
Address: No.2888 Zhongsheng Road, North Lake Science & Technology Development Zone, Changchun, Jilin Province, China