Sintering as a key technology for the energy transition and e-mobility

Assemblies with high-performance semiconductors are key components for the global energy transition and electromobility. For this reason, Tresky GmbH from Hennigsdorf near Berlin has been working on this key technology for some time and will present further product and process innovations in 2023 as part of additional development steps.

DIE Attach or DIE Bonding is the generic term for the process of permanently bonding a semiconductor DIE to a substrate, package, wafer or other component. In the sintering process, the DIE is very well bonded to the substrate not only electrically but also thermally by means of silver and, more recently, copper paste. This is done with the aid of heat and pressure. In this process, the silver or copper particles are bonded together by diffusion processes. The advantage over normal soldering processes is the very high thermomechanical stability, which is required above all in power electronics.

"The service life and energy efficiency of these assemblies essentially determine the efficiency and economic success of the process in which the assembly fulfills its function. State-of-the-art assembly and joining technology is the solution here to today's problems in the production of power electronic assemblies," says Daniel Schultze, managing director of Tresky GmbH. In copper and silver sintering, the paste dispensing and the placement of the semiconductor are the most important process steps. "We have developed a process that combines these two important steps, the two-dimensional application of the Cu or Ag sintering paste to the substrate, and the placement of the power semiconductor in one system," Schultze continues. This combination, coupled with the already established Tresky process modules, enables cycle-time-optimized production in which reproducible results are guaranteed.

Furthermore, the sintering process can be combined with additional options, such as the picking from wafer, the bonding of components with high force, and the dispensing of a tacking agent. The latter supports the positioning and fixing of the DIE on the substrate provided with sintering paste. This avoids the need to press the DIE during the assembly process, which is otherwise used to fix the semiconductor prior to vacuum soldering. For this purpose, four dispensing points are set before the DIE is placed, which fix the component in place. "This gives our customers a clear advantage in terms of their time to market, as development and series production can be implemented quickly and reliably," says Schultze.