Inductive Sintering of Silver Micro Particles for Bonding of Microelectronic Components

In this article, an efficient die-bonding technology based on silver sintering due to induction heating is presented. By using this technology, the heat for the sintering reaction is locally limited to the bonding area and heating of the entire power module is avoided. Furthermore, the sintering reaction is promoted due to current flow between the silver particles, and the sintering time is drastically reduced. Next to the experimental trials presented in this paper, finite element (FE) simulation methods were applied to develop a suitable induction coil geometry for the bonding of a diode to a direct bonded copper (DBC) substrate. Additional heating and sintering tests verified the reliability of the simulation model as well as the technological approach. Diodes were successfully bonded during the experiments and were analyzed by means of scanning electron microscopy (SEM) and function tests to qualify the inductive bonding technology. The results presented in this paper demonstrate that induction heating has high potential for cost-effective production in the field of die attach and can drastically increase the output in power-electronics production.