Nidec-read Corporation

Yoshio Tsuji

Masayoshi Yamada

Masami Yamamoto

A laser beam irradiation unit irradiates a laser beam on a top surface pattern portion of a wiring to be inspected among plural wirings formed on a substrate, with an intensity high enough to cause laser abrasion or two-photon absorption at the irradiated portion. A D.C. power supply applies, via an ammeter, a predetermined voltage between an electrode portion that traps electrons released from the top surface portion and a contact prove pressed against a bottom surface pattern of the wiring. An open circuit state and a short-circuit state of the wiring are judged using a current value measured in the ammeter. It is thus possible to inspect a wiring for an open circuit and a short-circuit easily without bringing a probe into contact with the lands of wirings on a top surface of the substrate to be inspected.

Substrate inspection device and substrate inspecting method

A circuit board testing apparatus for testing continuity and/or short-circuit of wirings formed on a circuit board, includes an electromagnetic wave irradiator which irradiates first terminals of the wirings with an electromagnetic wave so that electrons are discharged from the first terminals by photoelectric effect. Discharged electrons are trapped by an electrode which is electrically biased to have a higher potential than that of the second terminals of the wirings, thereby causing an electric current to flow through the wirings via the electrode. Existence of open-circuit and/or short-circuit of the wirings is judged based on the current flowing the wirings.

Growing community of inventors

Kyoto, Japan

Yoshio Tsuji