A self scrubbing buckling beam
contactor for contacting an array of pads positioned on a
device under test is described. The
contactor consists of three insulating dies: a top, an offset and a lower die separated from each other by an insulated spacer of
variable thickness. Each die is provided with holes. The buckling beam has an array of flexible wires positioned substantially perpendicular to the dies, each of the flexible wires crossing a corresponding hole in each of the top, offset and lower dies to allow each wire respectively contact a pad of the
device under test. By shifting the center of the hole of the lower die relative to the center of the offset die, the tip of the wire exits from the lower die at an angle with respect to the plane formed by the pads of the
device under test. The
exit angle of the wire tip is controlled by the
relative displacement of the offset die relative to the bottom die, such that the
exit angle of the tip of the wire at the bottom die changes when the probe wire is under compression. By applying a
reciprocating motion to the tip of the wire contacting the surface of the device under test, a scrubbing motion is achieved that lowers the resistance between the pad of the device under test. In this manner, the tip of the wire cleans the surface of the pads and prevents contaminants from adhering to the tip of the wire.