Laser-welded connections for high-power electronics in mobile systems

AbstractLaser welding of direct copper-aluminumconnections typically leads to the formation of intermetallicphases and an embrittlement of the metal joints. Consideringmobile systems such an embrittlement reduces the durabilityagainst temperature cycling as well as against dynamic loadsignificantly and limits the overall long-term stability. By meansof adapted filler materials it is possible to reduce the brittlephases and thereby enhance the ductility of these dissimilarconnections. As the element silicon features quite a wellcompatibility with copper and aluminum, filler materials basedon Al-Si and Cu-Si alloys are used in the current researchstudies. In contrast to direct Cu-Al welds, the aluminum filleralloy AlSi12 effectuates a more uniform element mixture and asignificantly enhanced ductility5 Halama