US Patent 7362116 Method for probing impact sensitive and thin layered substrate

A method of moving a substrate to a probe card. The method includes moving a probe card and a substrate vertically closer to one another employing dynamically changing velocities during the moving. More than two different velocities are used during the moving. The velocities are at zero only at an initial location and a final location. The moving is such that the probe card and the substrate contact each other with a soft impact. The velocities for the moving begin with a high velocity and reduce to a lower velocity so that the contact between the probe card and the substrate has a microtouch impact.