| 摘要 |
PURPOSE:To detect a pattern without producing a shadow or halation by a method wherein an object under inspection is illuminated by using a coaxial incident illuminator incorporated in a tube and by using a ring-shaped illuminator composed of an optical fiber installed at a tip part of the tube. CONSTITUTION:An optical inspection apparatus is equipped with the following: a tube 23 which has been arranged and installed above a stage 22 where a submount 1 is placed; a camera 24 which has been arranged and installed at its upper part. A coaxial incident illuminator 25 is installed in a halfway part of the tube 23. Light 30 which has traveled to the lower part of the tube 23 is reflected at the submount 1; reflected light 31 reflected by the surface passes through a half mirror 29, changes its light path at a prism 32 and reaches the camera 24. On the other hand, a ring-shaped illuminator 34 is arranged and installed at an outer periphery of an objective part 33; an optical fiber 36 extended inside a light guide 35 is buried inside a ring body 37. Accordingly, in object under inspection is illuminated by using the coaxial incident illuminator and its whole peripheral part is illuminated by using the ring-shaped illuminator; the quantity of light can be adjusted; accordingly, a pattern can be inspected accurately without producing a shadow or halation. |
