Enhancing Flexibility in Power Electronics Production: A Study on Robotic Handling of Copper Clips for Laser Bonding

Abstract

The production of power electronic modules re-quires cost-effective manufacturing of customer-specific small batches to meet today's requirements. Consequently, traditional methods of production are being replaced by highly flexible and fully automated manufacturing processes. This paper introduces a novel approach: a robot-assisted laser beam welding method designed to join copper clips with power modules' Direct Bonded Copper substrates and power terminals. The proposed setup involves using two six-axis articulated robots to assemble the components. Additionally, stationary scanner optics are utilized to guide a laser beam with a wavelength of 515 nm in order to establish the connections. To investigate the feasibility of the proposed approach initial experiments which focus on examining the influence of the pick and place process on the laser beam welding were conducted. The results demonstrate the feasibility of the manufacturing concept while showing a correlation between the geometry of the copper clamp, the clamping force and the resulting gap between the welded copper clamp and the Direct Bonded Copper. The findings obtained from these experiments contribute valuable insights toward the development of a flexible and reliable production method for power electronic modules.