| 摘要 |
PURPOSE:To carry out penetration hole testing without any connection with a conductor adhered on an inner wall by providing a slit, which accepts only the penetration of light reflected on the surface of a green sheet, to an image formation plane of a measurement system which measures said reflected light from a slanted direction. CONSTITUTION:An irradiation system 2 irradiated laser light 22 vertically to a green sheet 1 while a slanted observation system 3 observes only the reflected light 33 from the sheet 1 from the slanted direction. A slit 34, which only accepts the penetration of reflected light from the sheet 1, installed to the image formation plane of the observation system 3. When a conductor 12 is filled up to the upper end of a penetration hole 11, the reflection light on the upper surface of the conductor 12 passes through the penetration hole 34. When the hole 11 is void or a space is present on the upper part of the conductor 12, the reflected light on the upper surface of the conductor 12 can not pass through the slit. When there is a space on the upper part of the conductor and the conductor is not adhered on the inner wall, the reflected light on the upper part of the conductor, even it leaks from the hole, is cut off with the slit 34. As a result, the output of an optical detector 32 is turned to 'H' only when the conductor fills the hole 11 up to the opening end, which makes it possible to carry out high reliability penetration testing. |
