Marconi Instruments Limited

John L Smith

Frank H Jenner

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.

An electrical probe apparatus for facilitating the testing of printed circuit boards is constructed in a gas tight manner. This allows the printed circuit board to be held by suction without losing vacuum pressure through the probe. A silicon rubber sleeve serves as the vacuum seal, and its resilience urges the probe into firm contact with the circuit under test.

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St. Albans, United Kingdom

John L Smith