Abstract: A probe station includes a fully guarded chuck assembly and connector mechanism for increasing sensitivity to low-level currents while reducing settling times. The chuck assembly includes a wafer-supporting first chuck element surrounded by a second chuck element having a lower component, skirting component and upper component each with a surface portion extending opposite the first element for guarding thereof. The connector mechanism is so connected to the second chuck element as to enable, during low-level current measurements, the potential on each component to follow that on the first chuck element as measured relative to an outer shielding enclosure surrounding each element. Leakage current from the first chuck element is thus reduced to virtually zero, hence enabling increased current sensitivity, and the reduced capacitance thus provided by the second chuck element decreases charging periods, hence reducing settling times.
Type:
Grant
Filed:
April 21, 2005
Date of Patent:
February 12, 2008
Assignee:
Cascade Microtech, Inc.
Inventors:
Randy J. Schwindt, Warren K. Harwood, Paul A. Tervo, Kenneth R. Smith, Richard H. Warner
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 to 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.
Abstract: An interconnect assembly for evaluating a probe measurement network includes a base, respective inner and outer probing areas in mutually coplanar relationship on the upper face of the base, a reference junction, and a high-frequency transmission structure connecting the probing areas and the reference junction so that high-frequency signals can be uniformly transferred therebetween. A preferred method for evaluating the signal channels of the network includes connecting a reference unit to the reference junction and successively positioning each device-probing end that corresponds to a signal channel of interest on the inner probing area.
Type:
Grant
Filed:
January 11, 2007
Date of Patent:
January 22, 2008
Assignee:
Cascade Microtech, Inc.
Inventors:
Eric W. Strid, Jerry B. Schappacher, Dale E. Carlton, K. Reed Gleason
Abstract: A shielded probe for measuring the electrical characteristics of integrated circuits or other microelectronic devices at high frequencies. The probe may include a probe tip that extends through a dielectric substrate that supports on a first surface a signal path to test instrumentation and on a second surface a ground path that shields both the signal path and the probe tip.
Type:
Grant
Filed:
December 1, 2006
Date of Patent:
December 4, 2007
Assignee:
Cascade Microtech, Inc.
Inventors:
K. Reed Gleason, Tim Lesher, Eric W. Strid, Mike Andrews, John Martin, John Dunklee, Leonard Hayden, Amr M. E. Safwat
Abstract: A cable includes an inner conductor, an inner dielectric, and a guard conductor, where the inner dielectric is between the inner conductor and the guard conductor. The cable also includes an outer dielectric, and a shield conductor, where the outer dielectric is between the guard conductor and the shield conductor. The cable further includes an additional layer of material between the outer dielectric and the shield conductor of suitable composition for reducing triboelectric current generation between the outer dielectric and the shield conductor to less than that which would occur were the outer dielectric and the shield conductor to directly adjoin each other.
Type:
Grant
Filed:
September 27, 2006
Date of Patent:
November 13, 2007
Assignee:
Cascade Microtech, Inc.
Inventors:
Timothy Lesher, Brad Miller, Clarence E. Cowan, Michael Simmons, Frank Gray, Cynthia L. McDonald
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:
October 11, 2006
Date of Patent:
November 6, 2007
Assignee:
Cascade Microtech, Inc.
Inventors:
Clarence E. Cowan, Paul A. Tervo, John L. Dunklee
Abstract: A direct current and a modulation signal are simultaneously applied to contact pads on a device under test, such as a laser diode, with a probe that reduces signal distortion and power dissipation by transmitting a modulated signal through an impedance matching resistor and transmitting of a direct current over a second signal path that avoids the impedance matching resistor.
Type:
Grant
Filed:
March 5, 2007
Date of Patent:
October 23, 2007
Assignee:
Cascade Microtech, Inc.
Inventors:
Leonard Hayden, Scott Rumbaugh, Mike Andrews
Abstract: A probe measurement system for measuring the electrical characteristics of integrated circuits or other microelectronic devices at high frequencies. The probe measurement system preferably includes a probe having a conductive path extending between the first and second surfaces of a membrane and a probe contact electrically connected to the conductive path.
Type:
Grant
Filed:
March 28, 2006
Date of Patent:
September 18, 2007
Assignee:
Cascade Microtech, Inc.
Inventors:
K. Reed Gleason, Tim Lesher, Mike Andrews, John Martin
Abstract: A substrate, preferably constructed of a ductile material and a tool having the desired shape of the resulting device for contacting contact pads on a test device is brought into contact with the substrate. The tool is preferably constructed of a material that is harder than the substrate so that a depression can be readily made therein. A dielectric (insulative) layer, that is preferably patterned, is supported by the substrate. A conductive material is located within the depressions and then preferably lapped to remove excess from the top surface of the dielectric layer and to provide a flat overall surface. A trace is patterned on the dielectric layer and the conductive material. A polyimide layer is then preferably patterned over the entire surface. The substrate is then removed by any suitable process.
Type:
Grant
Filed:
January 14, 2005
Date of Patent:
September 11, 2007
Assignee:
Cascade Microtech, Inc.
Inventors:
Reed Gleason, Michael A. Bayne, Kenneth Smith, Timothy Lesher, Martin Koxxy
Abstract: A probe station for probing a test device has a chuck element for supporting the test device. An electrically conductive outer shield enclosure at least partially encloses such chuck element to provide EMI shielding therefor. An electrically conductive inner shield enclosure is interposed between and insulated from the outer shield enclosure and the chuck element, and at least partially encloses the chuck element.
Type:
Grant
Filed:
June 9, 2006
Date of Patent:
July 31, 2007
Assignee:
Cascade Microtech, Inc.
Inventors:
Ron A. Peters, Leonard A. Hayden, Jeffrey A. Hawkins, R. Mark Dougherty
Abstract: A probe assembly suitable for making test measurements using test signals having high currents. The disclosed probe assembly provides for a test signal exhibiting relatively low inductance when compared to existing probe assemblies by preferably reducing the electrical path distance between the test instrumentation and the electrical device being tested.
Abstract: A system for low-current testing of a test device includes a probing device for probing a probing site on the test device. The probing device includes a dielectric substrate having first and second sides, an elongate conductive path on the first side of the substrate, an elongate probing element connected to the elongate conductive path so as to extend in a cantilevered manner beyond the substrate, and a conductive area on the second side of the substrate. The probe housing is matingly detachably engageable with the probing device.
Abstract: A probe assembly having a switch that selectively electrically connects, for example, either a Kelvin connection or a suspended guard element with the probe assembly.
Abstract: A direct current and a modulation signal are simultaneously applied to contact pads on a device under test, such as a laser diode, with a probe that reduces signal distortion and power dissipation by transmitting a modulated signal through an impedance matching resistor and transmitting of a direct current over a second signal path that avoids the impedance matching resistor.
Type:
Grant
Filed:
May 25, 2006
Date of Patent:
April 17, 2007
Assignee:
Cascade Microtech, Inc.
Inventors:
Leonard Hayden, Scott Rumbaugh, Mike Andrews
Abstract: A probe station for probing a test device has a chuck element for supporting the test device. An electrically conductive outer shield enclosure at least partially encloses such chuck element to provide EMI shielding therefor. An electrically conductive inner shield enclosure is interposed between and insulated from the outer shield enclosure and the chuck element, and at least partially encloses the chuck element.
Type:
Grant
Filed:
November 3, 2004
Date of Patent:
March 13, 2007
Assignee:
Cascade Microtech, Inc.
Inventors:
Ron A. Peters, Leonard A. Hayden, Jeffrey A. Hawkins, R. Mark Dougherty