To solve the following problems: deflection due to dead weight may occur when a printed circuit board that is an object is large since images are picked up by X-ray irradiation spreading cylindrically when an X-ray transmission image is imaged by an X-ray generator that is a spot-like X-ray generation source; the distance between the printed circuit board and the X-ray generation point of the X-ray generator is changed when the deflection occurs; geometric conditions for projection are inaccurate; and a stable image cannot be obtained.
A carbon plate is installed below the printed circuit board that is the object, and a ball mechanism for supporting the carbon plate from a lower portion prevents the deflection occurring from the dead weight of the printed circuit board, thus maintaining the specific distance between the printed circuit board and the X-ray generation point of the X-ray generator.
HIROKAWA SATOSHI
KITAMURA SATORU
