| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a board inspection apparatus by which the magnification chromatic aberration of a secondary electron beam can be suppressed, while the irradiation region of a primary electron beam is being ensured, to provide an inspection system provided with the board inspection apparatus, and to provide a control method for the board inspection apparatus. SOLUTION: In a board inspection apparatus 90 which uses a nearly rectangular electron beam, an image-forming optical system as a telecentric system which is conjugate with an image-formation optical system in which a third lens 23 and a fourthlens 24 are controlled by secondary-optical system lens control parts 55, 56 and which is formed of a cathode lens 21 and a second lens 22 is formed, and square aperture diaphragms are arranged at focal planes 8, 9 which are mutually conjugate. As the square aperture diaphragms, movable rectangular diaphragms which are connected respectively to a driving mechanism using a piezoelectric element, comprising two rectangular flat boards arranged and installed in parallel in the direction of the long direction and in which their diaphragm widths formed of edges of sides facing to the rectangular flat boards can be adjusted are used. The movable rectangular diaphragms are arranged and installed in such a way that their long axis becomes a direction identical to that of the long axis of the cross-sectional shape of a primary electron beam 5 and that the long axis is at right angles to the long axis of the movable rectangular diaphragms.</p> |
