Abstract: A method of electrically testing an electrical component containing a plurality of networks with at least one node. The method uses segmented, charge limiting testing to charge the nodes and detect shorted or disconnected nodes while preventing accumulated charges in the networks from making uncharged nodes appear charged. The method is well suited for voltage contrast electron beam testing of unpopulated high density multichip modules and interconnect substrates.

Abstract: An electron beam testing apparatus for applying an electron beam to parts of an electronic component and measuring the secondary electrons released from the part including a secondary electron collector having a plurality of vertically extending screens with a detector positioned adjacent one of the screens. A different voltage is applied to each of the screens of the collector for collecting the secondary electrons over a large area. The apparatus may include a combination blanking and Faraday cup for metering the electron beam current when it is blanked. The apparatus may also be used to measure net work capacitance by measuring the time required to charge a network to a predetermined voltage.