Reliability of pressure-free Cu nanoparticle joints for power electronic devices

Novel pressure-free Cu nanoparticle joints for power electronic devices were fabricated, and their reliability was investigated. Si heater chips were bonded to Cu-65Mo baseplates without applied pressure in a N2 atmosphere. The increase in thermal resistance was found to be less than 30% after 1000 thermal cycles of −40/150 °C and −40/200 °C. Samples with Ag- or Cu-coated baseplates showed no deterioration following 3000 power cycles of 65/250 °C. In contrast, samples with baseplates coated with Au or Ni exhibited an increase in thermal resistance in power cycle tests of 65/200 °C and 65/250 °C.