Patent ID: 8427186

Claim:
A microelectronic probe element for making pressure-based electrical contact to a microelectronic device for testing said microelectronic device, said microelectronic probe element comprising: a base; a tip electrically connected to said base and comprising a conductive material suitable for making pressure based electrical contact to a microelectronic device; a spring assembly coupled between said tip and said base, said spring assembly comprising: a first spring, wherein said first spring has a first spring characteristic comprising a negative stiffness over a predefined displacement range of said tip relative to said base; and a second spring, wherein said second spring has a second spring characteristic comprising a positive stiffness over said predefined displacement range, wherein said first spring and said second spring are coupled so that said positive stiffness substantially cancels said negative stiffness to produce a net spring characteristic of said tip relative to said base over said predefined displacement range.