Ultrasonic wire bonding has been established for decades as a key bonding process in microelectronics and the semiconductor industry. In the current context of the energy transition, developments are focusing on the weight, compactness and performance of electronic components, for example in the automotive industry. Furthermore, the rising energy demand in power electronics requires electrical connections with ever-larger conductor cross-sections.

In the ERDF-funded HoLeiB project, a vibration system was developed which, through multidimensional, multi-frequency excitation, achieves a higher ultrasonic power output than is the case with conventional ultrasonic wire bonding. This concept served as the basis and was further developed for ultrasonic wire bonding as part of the EU‘Power2Power’project. The project investigated whether the higher ultrasonic power enables wires with large diameters to be bonded more robustly than with conventional ultrasonic wire bonding. At the same time, the study investigated whether the multidimensional excitation during the bonding process is gentler on the substrate compared to conventional ultrasonic wire bonding, with a view to contributing to the sustainability of electronic components, as this can result in a longer service life for the components. The investigations carried out showed that, in the case of aluminium wire bonding, bond qualities comparable to those achieved with conventional ultrasonic wire bonding were obtained; however, no significant advantage was achieved in terms of damage to the substrate. In contrast, multidimensional wire bonding with copper wire significantly reduced cracks in the chip. However, compared with conventional ultrasonic wire bonding, more cracks occurred in the chip’s metallisation layer.