Thermal fatigue resistant electrical contact to silicon

[jedward]

Looking for proven method of making electical contacts to silicon chips that can withstand cycling -100C to + 100C > 20,000 cycles with cycle time of few minutes. Am attempting to join kovar to plated silicon using soldering. Has any one done this? All suggestions appreciated.

 

[btrueblood]

Gold is attractive for this application, since its ductility allows it to "absorb" a lot of the imposed thermal strains, and it remains highly conductive.