Hitachi, Ltd.

Toshihiko Ayabe

Takanori Ninomiya

Asahiro Kuni

Toshimitsu Hamada

Kozo Nakahata

Toshiaki Ichinose

A method and an apparatus for inspecting a soldered joint with an X-ray, the soldered joint being formed by soldering a lead to a surface of a substrate. The method may include moving the substrate so as to move the surface of the substrate in an XY plane to position the soldered joint at a desired position in the XY plane, rotating the substrate so as to rotate the surface of the substrate in the XY plane to position the soldered joint at a desired orientation in the XY plane, rotating an X-ray source and a detector about the soldered joint in both of two mutually perpendicular planes perpendicular to the XY plane while maintaining the X-ray source and the detector at fixed positions relative to each other to establish a desired oblique irradiation angle between an X-ray from the X-ray source and the lead on the surface of the substrate, irradiating the soldered joint with the X-ray from the X-ray source at the desired oblique irradiation angle such that the X-ray is transmitted through the soldered joint and the substrate, detecting the X-ray transmitted through the soldered joint and the substrate with the detector, the detector producing an output signal indicative of the detected X-ray, and determining a condition of the soldered joint based on the output signal of the detector. The apparatus may operate in the same fashion.

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Yokohama, Japan

Toshihiko Ayabe