MEMS spring probe for next generation wafer level testing

MEMS spring probe was fabricated for a nondestructive contact and testing of ultra small pitch devices. The probes have high suspension from the bottom planar surface, high elastic spring constant, and low interface contact resistivity. All contacts take place simultaneously. The contact interface area of the fabricated probe was 70 μm². Low RF signal loss was observed from RF testing. Measured S₁₁ parameter was approximately -50 dB and S₂₁ was -0.5 dB up to 30 GHz. The total resistance of the probe was 2 ohms and the inductance and capacitance were negligible.