Ultrasonic Welding of Al Busbars to Cu Contacts: The Role of Laser Structuring and Connection Reliability in Meeting IEC 60352–9 Standards

This study specifically addresses the challenges of ultrasonic welding (USW) to create connections between aluminum busbars and copper contacts in accordance with the quality standards defined by IEC 60352–9. This standard outlines the requirements for ultrasonically welded connections used in high reliability electronic assemblies. Our research focuses on the effects of film contamination and surface topography optimization on weld efficiency and durability. We highlight the detrimental effect of film contaminants on the electrical and mechanical stability of interconnects and show how optimized surface topography, achieved by laser structuring, plays a key role in improving weld strength. In addition, our research includes the analysis of intense vibrations during the USW process through simulations, highlighting the potential material degradation, especially when joining Al busbars to Cu contacts. The application of laser structuring for surface preparation is shown to be a critical factor in minimizing adverse effects and ensuring the integrity and performance of electrical contacts. Our results underscore the need for precise process control and advanced surface preparation techniques to meet the standards set by IEC 60352–9 and improve the reliability of electrical interconnection manufacturing.