摘要 |
A probe fixture for making multiple high frequency connections to an electronic device under test. An application for the apparatus is in integrated circuit wafer testing fixtures requiring high frequency signals. Low frequency signals are attached by ribbon cables to a printed circuit board. High frequency signals use coaxial cables. A probe carrying ceramic substrate has microstrips for the high frequency signals. Low frequency signals are connected from the printed circuit board to the ceramic substrate by a conductive elastomer interconnect strip clamped between the printed circuit board and the substrate. Coaxial adapters passing through the printed circuit board have spring loaded center conductors to provide pressure contact between the coaxial cables and microstrip signal strips. In one embodiment, contact between coaxial cable shields and microstrip ground is through a conductive clamp to a substrate backplane. In an alternative embodiment, contact between a coaxial cable shield and the microstrip ground is provided by a flat spring connected to a barrel on the coaxial adapter connector body and in pressure contact with coplanar ground contacts on the substrate. In the alternative embodiment, a short ground path from the cable shield to the microstrip ground minimizes transmission line impedance discontinuity.
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