Cascade Microtech, Inc.

Credence Systems Corporation

Daniel L Harris

Peter McCann

A chuck adapted to test electrical and/or optical components on a device-under-test (DUT).

Optical testing device

A rotary chuck with indexed rotation promotes rapid rotation of a device under test and increases the productivity of a probe station on which the device is being tested. A device mounting member of a rotatable chuck is supported for rotation on a first surface of a base until a vacuum is applied drawing the device mounting member into contact with a second surface of the base and constraining the device mounting member against rotation.

Indexing rotatable chuck for a probe station

The arrangement of test points on an integrated circuit (IC) undergoing testing in a probe station often requires rotation of the IC or the probes when performing a series of tests. A chuck with indexed rotation promotes rapid rotation of the device under test to a new test position and increases the productivity of the probe station. The device under test is mounted on a device mounting member that is affixed to a shaft rotationally mounted in a base. A resilient seal supports the device mounting member and forms a sealed chamber over a substantial part of the area of the device mounting member. Applying vacuum or pressure to the sealed chamber urges the device mounting member and base toward contact. The support provided by the resilient seal over substantial portion of device mounting member's diameter promotes stability and consistent planarity of the device mounting member without regard to the orientation of the shaft to device mounting member.

An electrical parameter of a rod-form conductive element is measured using a measurement fixture which includes an insulating support on which a first conductive element is mounted. A transmission line connector mounted on the insulating support and has a signal conductor connected to a first conductive element mounted on the support member. A holder for removably receiving the rod-form element includes a conductive member which is in electrically conductive contact with the rod-form element when the latter is positioned in the holder. The holder is mounted relative to the support member by a mounting structure such that when the rod-form element is positioned in the holder, an end of the rod-form element can be brought into electrically conductive contact with the first conductive element. The mounting structure includes a resistor structure electrically connected between the conductive member of the holder and the ground conductor of the transmission line connector and having an electrical resistance substantially equal to the characteristic impedance of the transmission line connector.

Growing community of inventors

Beaverton, OR, United States of America

Daniel L Harris