Marconi Instruments Limited

Frank H Jenner

John L Smith

Ricki E White

Patrick C Thompson

In an interface arrangement for automatic test equipment a substrate, such as a circuit board, is supported between spring loaded test probes within a vacuum chamber so that application of a vacuum causes the probes to contact the board. An internal dam is mounted within the vacuum chamber and, upon the application of the vacuum, seals off an internal portion of the chamber containing the probe arrays so that cooling air may be applied to the circuit board without breaking the vacuum in the outer portion of the chamber. Access may also be provided to the circuit board in this condition.

Electrical interface arrangement

An electrical interface arrangement enables a complex circuit board to be connected to an electrical test equipment to verify the correct operation of the circuit board or to identify malfunctions. The interface arrangement makes electrical contact with predetermined points of the circuit board and connects these points to predetermined terminals of the test equipment. Each electrical interface arrangement is likely to be unique to a particular type of circuit board, and it has proved very difficult and time consuming to reliably interconnect the contacts of the electrical interface arrangement--typically 200 to 300 interconnecting leads are required. To facilitate the interconnection process, the interface arrangement is provided with a movable connector which in one position co-operates with the test equipment and which in another position is such that its terminals lie in substantially the same plane as those of the electrical contacts which, in operation, touch the predetermined locations of the circuit board. In the latter position the two sets of terminals can be interconnected very readily using a semi-automatic wiring machine.

Electrical interface arrangements

An electrical interface arrangement enables a circuit board to be connected to test equipment for the purpose of verifying its correct operation or enabling malfunctions to be identified. The interface arrangement carries a two dimensional array of electrical contacts which, in operation, are brought into touching contact with predetermined locations of the circuit board. It is necessary to hold the circuit board firmly in contact with the array of contacts in exactly the correct alignment. The invention provides a common housing which serves to locate the circuit board in alignment with the two dimensional array of contacts and either the circuit board can be secured to the housing by means of a suction effect generated by a suction chamber located within the housing, or alternatively the circuit board can be secured by means of an externally located pressure plate.

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St. Albans, United Kingdom

Frank H Jenner