Probe head structures for circuit probe test systems and methods of forming the same

Abstract

A probe card for a circuit probe test system and methods of fabrication thereof. The probe card includes a substrate portion, a guide plate having a plurality of openings, and a plurality of probe pins extending through the openings, including at least one first probe pin configured to carry power between the substrate portion and a device-under-test (DUT), at least one second probe pin configured to electrically couple the DUT to ground, and at least two third probe pins configured to carry loopback test signals between contact regions on the DUT. A low dielectric constant (low-k) material may be located between the third probe pins and the guide plate. The low-k material may prevent direct contact between the third probe pins and the relatively higher dielectric-constant material of the guide plate, which may improve the signal integrity (SI) of the loopback test signals.