Laserbonding instead of ultrasonic wire bonding — An alternative joining technology for power applications

Laserbonding is a newly developed technology that combines the flexibility and robustness of classical ultrasonic wire-bonding with the advantages of laser welding as regards large connector cross-sections, low quality requirements to surf aces and clamping rigidity. Thanks to modern laser sources with high brilliance, near-infrared radiation can be used in oscillation welding Cu even in a keyhole fashion even though Cu is traditionally considered illsuited for such laser wavelengths. The process is most useful for connecting copper ribbons of 2 × 0, 2 mm size to Li battery cells of the 18650 type but can also be adapted for larger prismatic cells. Further development is geared towards connecting power semiconductors.