Reliability of low current electrical spring contacts in power modules

摘要

Advanced power module designs simplify the assembly process by electrical pressure contact technology. This technology can be applied to load connectors, control contacts and auxiliary sensor contacts. While the advantages for the assembly process are widely accepted, there is still concern about the long term stability of electrical spring contacts in power applications. However, knowledge base on wrap connector contacts which seems to support this concern cannot be applied due to important differences in construction. Employing Sn plus or Ag plated surfaces on the spring contact interface leads to reliable electrical contacts, that meet the demands of contact force and environmental stability. Accelerated thermal, environmental and mechanical tests will be presented, that prove the excellent reliability of the spring contact system.