Patents by Inventor Clarence E. Cowan

Clarence E. Cowan has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20040150416
    Abstract: To reduce noise in measurements obtained by probing a device supported on surface of a thermal chuck in a probe station, a conductive member is arranged to intercept current coupling the thermal unit of the chuck to the surface supporting the device. The conductive member is capacitively coupled to the thermal unit but free of direct electrical connection thereto.
    Type: Application
    Filed: July 25, 2003
    Publication date: August 5, 2004
    Inventors: Clarence E. Cowan, Paul A. Tervo, John L. Dunklee
  • Publication number: 20040027145
    Abstract: A low-current pogo probe card for measuring currents down to the femtoamp region includes a laminate board having a layer of conductive traces interposed between two dielectric layers. A plurality of probing devices, such as ceramic blades, are edge-mounted about a central opening so that the probing needles or needles included therein terminate below the opening in a pattern suitable for probing a test subject workpiece. A plurality of pogo pin receiving pad sets, each including a guard pad, occupy the periphery of the board. Each guard pad is electrically connected to a trace from the layer of conductive traces. The pad sets may be connected to the probing devices by low noise cables or traces. Air trenches separate the pad sets for reducing cross talk and signal settling times.
    Type: Application
    Filed: July 7, 2003
    Publication date: February 12, 2004
    Inventors: Paul A. Tervo, Clarence E. Cowan
  • Publication number: 20040017214
    Abstract: A low-current pogo probe card for measuring currents down to the femtoamp region includes a laminate board having a layer of conductive traces interposed between two dielectric layers. A plurality of probing devices, such as ceramic blades, are edge-mounted about a central opening so that the probing needles or needles included therein terminate below the opening in a pattern suitable for probing a test subject workpiece. A plurality of pogo pin receiving pad sets, each including a guard pad, occupy the periphery of the board. Each guard pad is electrically connected to a trace from the layer of conductive traces. The pad sets may be connected to the probing devices by low noise cables or traces. Air trenches separate the pad sets for reducing cross talk and signal settling times.
    Type: Application
    Filed: March 13, 2003
    Publication date: January 29, 2004
    Inventors: Paul A. Tervo, Clarence E. Cowan
  • Patent number: 6642732
    Abstract: To reduce noise in measurements obtained by probing a device supported on surface of a thermal chuck in a probe station, a conductive member is arranged to intercept current coupling the thermal unit of the chuck to the surface supporting the device. The conductive member is capacitively coupled to the thermal unit but free of direct electrical connection thereto.
    Type: Grant
    Filed: December 2, 2002
    Date of Patent: November 4, 2003
    Assignee: Cascade Microtech, Inc.
    Inventors: Clarence E. Cowan, Paul A. Tervo, John L. Dunklee
  • Publication number: 20030132767
    Abstract: A membrane probing assembly includes a probe card with conductors supported thereon, wherein the conductors include at least a signal conductor located between a pair of spaced apart guard conductors. A membrane assembly includes a membrane with contacts thereon, and supporting at least a signal conductor located between a pair of spaced apart guard conductors. The guard conductors of the probe card are electrically interconnected proximate the interconnection between the probe card and the membrane assembly. The guard conductors of the membrane assembly are electrically interconnected proximate the interconnection between the probe card and the membrane assembly.
    Type: Application
    Filed: November 29, 2000
    Publication date: July 17, 2003
    Inventors: Paul A. Tervo, Kenneth R. Smith, Clarence E. Cowan, Mike P. Dauphinais, Martin J. Koxxy
  • Publication number: 20030117157
    Abstract: A low-current pogo probe card for measuring currents down to the femtoamp region includes a laminate board having a layer of conductive traces interposed between two dielectric layers. A plurality of probing devices, such as ceramic blades, are edge-mounted about a central opening so that the probing needles or needles included therein terminate below the opening in a pattern suitable for probing a test subject workpiece. A plurality of pogo pin receiving pad sets, each including a guard pad, occupy the periphery of the board. Each guard pad is electrically connected to a trace from the layer of conductive traces. The pad sets may be connected to the probing devices by low noise cables or traces. Air trenches separate the pad sets for reducing cross talk and signal settling times.
    Type: Application
    Filed: December 6, 2002
    Publication date: June 26, 2003
    Inventors: Paul A. Tervo, Clarence E. Cowan
  • Patent number: 6559668
    Abstract: A low-current pogo probe card for measuring currents down to the femtoamp region includes a laminate board having a layer of conductive traces interposed between two dielectric layers. A plurality of probing devices, such as ceramic blades, are edge-mounted about a central opening so that the probing needles or needles included therein terminate below the opening in a pattern suitable for probing a test subject workpiece. A plurality of pogo pin receiving pad sets, each including a guard pad, occupy the periphery of the board. Each guard pad is electrically connected to a trace from the layer of conductive traces. The pad sets may be connected to the probing devices by low noise cables or traces. Air trenches separate the pad sets for reducing cross talk and signal settling times.
    Type: Grant
    Filed: January 24, 2000
    Date of Patent: May 6, 2003
    Assignee: Cascade Microtech, INC
    Inventors: Paul A. Tervo, Clarence E. Cowan
  • Publication number: 20030080765
    Abstract: To reduce noise in measurements obtained by probing a device supported on surface of a thermal chuck in a probe station, a conductive member is arranged to intercept current coupling the thermal unit of the chuck to the surface supporting the device. The conductive member is capacitively coupled to the thermal unit but free of direct electrical connection thereto.
    Type: Application
    Filed: December 2, 2002
    Publication date: May 1, 2003
    Inventors: Clarence E. Cowan, Paul A. Tervo, John L. Dunklee
  • Patent number: 6512391
    Abstract: To reduce noise in measurements obtained by probing a device supported on surface of a thermal chuck in a probe station, a conductive member is arranged to intercept current coupling the thermal unit of the chuck to the surface supporting the device. The conductive member is capacitively coupled to the thermal unit but free of direct electrical connection thereto.
    Type: Grant
    Filed: June 24, 2002
    Date of Patent: January 28, 2003
    Assignee: Cascade Microtech, Inc.
    Inventors: Clarence E. Cowan, Paul A. Tervo, John L. Dunklee
  • Publication number: 20020167329
    Abstract: To reduce noise in measurements obtained by probing a device supported on surface of a thermal chuck in a probe station, a conductive member is arranged to intercept current coupling the thermal unit of the chuck to the surface supporting the device. The conductive member is capacitively coupled to the thermal unit but free of direct electrical connection thereto.
    Type: Application
    Filed: June 24, 2002
    Publication date: November 14, 2002
    Inventors: Clarence E. Cowan, Paul A. Tervo, John L. Dunklee
  • Patent number: 6445202
    Abstract: The chuck of a probe station is shielded from capacitive currents generated by fluctuation of the power to the thermal unit of a thermal chuck. The thermal chuck includes a chuck for supporting a device under test; a thermal unit for modifying the temperature of the chuck and a conductive member capacitively coupled to but free from direct electrical connection to the thermal unit. The conductive member is electrically connected to the controller supplying power to the thermal units. The conductive member intercepts substantially all of the capacitive currents emanating from the operation of the thermal unit and provides a conductive path to return these currents to the controller. An extension of the probe station's conductive environmental enclosure is capacitively coupled to the conductive member so as to intercept capacitive currents emanating from the conductive member and conduct these currents to ground outside of the environmental enclosure.
    Type: Grant
    Filed: June 30, 1999
    Date of Patent: September 3, 2002
    Assignee: Cascade Microtech, Inc.
    Inventors: Clarence E. Cowan, Paul A. Tervo, John L. Dunklee
  • Patent number: 6034533
    Abstract: A low-current pogo probe card for measuring currents down to the femtoamp region includes a laminate board having a layer of conductive traces interposed between two dielectric layers. A plurality of probing devices, such as ceramic blades, are edge-mounted about a central opening so that the probing needles or needles included therein terminate below the opening in a pattern suitable for probing a test subject workpiece. A plurality of pogo pin receiving pad sets, each including a guard pad, occupy the periphery of the board. Each guard pad is electrically connected to a trace from the layer of conductive traces. The pad sets may be connected to the probing devices by low noise cables or traces. Air trenches separate the pad sets for reducing cross talk and signal settling times.
    Type: Grant
    Filed: June 10, 1997
    Date of Patent: March 7, 2000
    Inventors: Paul A. Tervo, Clarence E. Cowan
  • Patent number: 4862020
    Abstract: An electronic delay control circuit provides small, constantly variable delays to an input pulse signal without altering the pulse width of the input signal. The input pulse signal together with a first reference signal are input to three comparators in parallel. The output of one comparator is a pulse signal corresponding to the input pulse signal, and the outputs of the other two comparators are tied together and input to a pulse shaping network to produce delay current pulses for the leading and trailing edges of the input pulse signal. The delay current pulses are added to the output pulse signal to produce a delayed output pulse signal. The delay current pulses are a function of the amount of a constant current steered between the two comparators as determined by a delay control signal.
    Type: Grant
    Filed: June 20, 1988
    Date of Patent: August 29, 1989
    Assignee: Tektronix, Inc.
    Inventors: Clarence E. Cowan, Ronald K. Christensen