| 摘要 |
PURPOSE:To accurately perform the positional determination of a through-hole, by judging that the through-hole is present at a set position when light from a light emitting optical fiber is not reflected and does not enter a light receiving optical fiber while passes the through-hole. CONSTITUTION:The under surface electrode 50b of a probe is slightly protruded from the upper surface of a table 2 and a focus adjusting plate 37 corresponding to the thickness of a wiring board (x) to be measured is inlaid with a placing circular groove 36. The wiring board (x) is placed and positional determination is visually performed so that a through-hole (y) is positioned on the moving line of an electrode 50 while light is irradiated from a light emitting optical fiber 47 and allowed to irradiate the wiring board (x) by the condensing lens 44 provided to the leading end of a fiber unit 41. When the through-hole (y) is not coincided with the moving line at this time, light is reflected from the wiring board (x) and reflected light is collected by the condensing lens 44 provided to the leading end of the other optical fiber unit 41 to recognize the inferiority of the positional determination of the through-hole (y). If the position of the through-hole (y) is accurately determined, reflected light is not detected because light passes the through-hole.
|
