Joseph P Golden

US Patent:

51967898, Mar 23, 1993

Filed:

Jan 28, 1991

Appl. No.:

7/646267

Inventors:

Joseph R. Golden - Cupertino CA
Brian T. Bernard - Saratoga CA

International Classification:

G01R 3102
G01R 1512

US Classification:

324158P

Abstract:

An improved spring loaded contact probe for testing printed circuit boards, electronic components, and substrates includes a center conductor, or wire, at least one outer layer of dielectric material surrounding the wire, a conductive layer surrounding the conductive layer, and a dielectric material surrounding the conductive layer, all in turn surrounded by a non-conductive bushing slidably mounted within a conductive tube and loaded by a compression spring with respect to the tube. One end of the tube has an end cap that contains and holds in place the compression spring. At the end of the center conductor, extending from the tube end opposite to the cap end, a conductive contact head is attached to center conductor, makes for making physical and electrical contact with the electronic component. In this way, electrical signals for test purposes can be applied to the center wire, and the conductive layer of the coaxial spring can be grounded through a suitable grounding lead, thereby preventing cross talk between other adjacent spring contact probes while still allowing the probes to be matched in impedance with the coaxial cable of the electrical tester, and to operate at higher frequencies.