| 摘要 |
PURPOSE:To prevent a circuit pattern from being misjudged to a foreign matter, by employing a flat spot-shaped scan laser beam. CONSTITUTION:A spot light A made flat in the direction of scanning (direction Y) employs that equal to the circular spot light B used in the conventional method in the axial length L, center peak intensity E and overall energy in the direction (X) perpendicular to the direction of scanning. With such an arrangement, the reflectionally scattered energy from the edge part C of a circuit pattern is proportional in the magnitude the length of the long segment PQ at the edge part C positioned inside in the case of the circular spot light B of the conventional method whereas it is proportional to the length of the short segment RS at the edge part C positioned inside in the case of the flat- shaped spot light A. Thus, the reflectionally scattered energy from the edge part C of the circuit pattern can be reduced to RS/PQ as compared with that in the past. |
