Micro-circuit test apparatus

Abstract

Testing of integrated circuit components of the silicon wafer type is accomplished by a test probe assembly mounted on a support table, the latter being spaced vertically with respect to a platform on which the circuit components are placed. The test probe assembly, which includes a probe test unit, is mounted on the support in such a fashion that the test probe may be moved to a precise predetermined position corresponding to the precise location of that portion of the integrated circuit to be tested. This is accomplished by mounting the assembly housing such that it moves arcuately with respect to its support structure, while providing a slide unit within the housing which is movable vertically as well as axially with respect to the housing. Once the proper predetermined position has been determined and the test probe assembly adjusted such that the probe is properly aligned with the particular portion of the integrated circuit to be tested, the entire assembly is maintained in proper position. Thereafter, by computer control, the platform supporting the integrated circuits to be tested is indexed in accordance with the predetermined program and each of the particular circuits of the integrated circuit units is tested in the desired sequence. The test probe assembly housing includes separate rotatable adjusting members which independently bring about axial and vertical movement of the slide member upon which the test probe is mounted. The probe test unit, supported by the slide, is connected by means of a cable to a suitable external control circuit for testing the individual circuits on the integrated circuit wafer. Also described is an improved probe arm assembly having a needle tip which operates to reduce the capacitive effect between closely spaced probe arms.