Measuring apparatus of state of surface

Abstract

Abstract PURPOSE:To increase a rate of separative detection of an extraneous substance by avoiding a diffracted light generated from a circuit pattern and by sensing selectively only a scattered light flux from the extraneous substance. CONSTITUTION:A beam from a laser 1 passed through a stop 101 and enters a beam expander 102, whereby the radius of the beam is expanded. Then, it is reflected by a polygon mirror 2 and made to fall on each position of a beam scan line on a circuit board 5, through a lens 61 whose optical axis is inclined at an angle alpha to the surface of the board and at an angle beta to the longitudinal direction. The polygon mirror 2 is rotated for scanning on the board 5, while it is moved on the board 5 for scanning the whole surface. A condenser element of a light-sensing optical system condenses a scattered light flux from an extraneous substance on the board 5, and the flux is focused on a focal point PG on the rear side of the lens 61, passed through a stop 103 and led onto the light-sensing surface of a light-sensing element 9 by a lens 8.

Inventors

• 👤 Michio Kono
• 👤 道生 河野
• 👤 Eiichi Murakami
• 👤 栄一 村上
• 👤 Akiyoshi Suzuki
• 👤 章義 鈴木

Bibliographic Details