Alongside ultrasonic wire bonding, the process of ultrasonic welding plays a key role in power semiconductor electronics. In particular, the terminal connections (known as control and load current terminals) of a power module are welded onto the substrate using this process. Compared with ultrasonic wire bonding, significantly more power is required to successfully form a connection due to the considerably larger geometries of the terminals. However, the fundamental mechanism of connection formation is similar.

To achieve a good welded joint, relative movement between the substrate and the current collector is required. This relative movement can be reduced by a substrate that vibrates in phase. It is therefore necessary to carry out a detailed investigation of the substrate dynamics during the welding process. Furthermore, these investigations can provide indications of potential damage caused, for example, by resonance effects in the substrate or to sensitive components such as wire bonds or semiconductors. In order to control the dynamics in the production process, complex clamping systems are usually developed for power electronics modules. Modelling the substrate dynamics is intended to facilitate the development of clamping systems by enabling their design to be based on a model. Experimental vibration analyses using laser vibrometry serve as the basis for this modelling. In the field of ultrasonic welding, the Chair works closely with Infineon Technologies AG Warstein, a manufacturer of power semiconductor modules.