Patent ID: 6366105
Filing Date: 2002-04-02
Classification: G01R

Abstract:
A method for testing an electrical circuit formed upon a substrate comprising:providing a substrate having an electrical circuit formed upon the substrate, the electrical circuit being accessed by a conductor contact also formed upon the substrate; positioning the substrate within an electrical test apparatus, the electrical test apparatus having a conductive probe tip fixed to the electrical test apparatus, the conductive probe tip being positioned in a first position in the proximity of but not in contact with the conductor contact; repositioning the conductive probe tip to a second position with respect to the substrate such that the conductive probe tip contacts the conductor contact while simultaneously purging the surface of the conductor contact with a purge gas stream; and obtaining an electrical measurement of the electrical circuit through the conductive probe tip in contact with the conductor contact while employing the electrical test apparatus, wherein the purging of the surface of the conductor contact with the purge gas stream is undertaken employing conditions such that when repositioning the conductive probe tip to the second position with respect to the substrate there is avoided a contact resistance increase of the conductive probe tip with respect to the conductor contact when contacting the conductor contact; wherein the purge gas stream is provided through a nozzle; the nozzle has an aperture having a diameter of from about 1 to about 2 millimeters; the nozzle is separated from the conductive probe tip by a distance of from about 40 to about 70 millimeters; and the purge gas stream has a purge gas flow rate of from about 85000 to about 90000 standard cubic centimeters per minute (sccm).