Observation device

Abstract

Provided is an observation device with which it is possible to observe an object surface of, for example, roughly 24.6*24.6mm, at a resolution of no more than 10 microns and at a large inclination angle which exceeds 45 degrees. An observation device 10 is provided with a light receiving surface 20 and an image forming optical system 30 for forming light from an object surface S into an image on the light receiving surface 20. The image forming optical system 30 includes a concave-surface primary mirror 32, a sub-mirror 34, and a flat extraction mirror 36. The beams of the light from the object surface S are reflected by the concave-surface primary mirror 32, the convex-surface sub-mirror 34, and the concave-surface primary mirror 32, in that order, and thereafter form an image on the light receiving surface 20 via the flat extraction mirror 36. The observation device 10 is provided with the following: a first tilting means which can change the angle alpha formed by the optical axis L1 of the light traveling from the object surface S towards the concave-surface primary mirror 32 and the perpendicular line N1 of the object surface S; and a second tilting means which can change the angle beta formed by the optical axis L2 of the light traveling from the flat extraction mirror 36 towards the light receiving surface 20 and the perpendicular line N2 of the light receiving surface 20.

Description

technical field [0001] The present invention relates to viewing devices. Background technique [0002] For example, in order to inspect defects of printed circuit boards, it is required to observe not only the two-dimensional shape of the surface of the printed circuit board but also the three-dimensional shape of the surface of the printed circuit board. That is, while observing the two-dimensional shape (XY plane shape) of the surface of the printed circuit board, it is required to observe the height (=height in the Z-axis direction) of the uneven shape on the surface. [0003] By observing the surface of the printed wiring board from directly above, the two-dimensional shape of the substrate surface can be measured. However, in order to obtain height information in the Z-axis direction, it is necessary to observe the uneven shape of the substrate surface from an oblique direction. For example, when the substrate surface is observed from an oblique direction, the width o...

AI Technical Summary

Problems solved by technology

[0010] In addition, when the imaging optical system of the observation device uses a refractive lens system, there is a problem that the wavelength band of light that can pass through the glass material used for the refractive lens is limited.

In this case, there is a problem that it is difficult to apply the observation device to the semiconductor and biological fields

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