Abstract: A testing device for a printed circuit includes a plate which is at least partly constituted by semiconducting material, and sensing elements for the transmission of testing signals between the testing device and the printed circuit. The sensing elements may be in the form of projections or coils integral with the plate or in the form of pins receivable in recesses of the plate. The printed circuit has pads for the transfer of testing signals between the circuit and the testing device, and the sensing elements are so densely packed that at least two sensing elements cooperate with each pad.

Abstract: Selected test points of conductors on the substrate of a printed circuit board are tested by positioning the circuit board adjacent an array of electrodes or by utilizing a set of conductors in or on the substrate as an array of electrodes. An electric potential is set up by applying an inhomogeneous electric field to the array of electrodes or to the conductors to be tested, and signals denoting the characteristics of the electric potential are generated. Such signals are evaluated by a suitable circuit, for example, by comparing them with reference signals which are indicative of passable or non-defective conductors, i.e., of conductors which are devoid of open and/or short circuits, or by comparing the generated signals with each other. Test probes are utilized to apply an electric field to the conductors to be tested and/or to transmit signals to the evaluating circuit.

Abstract: A multispindle machine for drilling, milling or the like of workpieces has several spindles mounted on at least one crossbeam rail (4), and the workpieces and spindles can be displaced relative to one another along X and/or Y coordinates. To minimize machining time, each crossbeam rail mounts at least two spindles (3) which are displaceably independently of one another in the long direction or X coordinate of the crossbeam rail (4).