FORM OF MICROSCOPIC DOT MARK USING LASER BEAM AND MARKING METHOD THEREOF

摘要

PROBLEM TO BE SOLVED: To obtain a dot marking method for enabling accurate formation of a microscopic dot, which is superior in visibility and has a singular form. ;SOLUTION: A laser beam balanced by a beam homogenizer 3 is passed through a liquid crystal mask 4 and is divided, the energy density of the divided laser beams is set at a density of 1.0 to 15.0 J/cm2, each laser beam which passed through the mask 4 in each one dot is reduced by a lens unit 6, so that the longest length of the one dot is formed with a length of 1 to 15 m and the image of the dot is made to form on an article W to be marked to form a dot mark. The dot mark obtained consists of a single dot mark in each laser irradiated point, the length of the central part of the above mark which extends along the surface of the rising part swelling upward from the surface of the article W is 1 to 15 m, the height of the swelling part is 0.01 to 5 m and, even through the dot is microscopic, it is formed into an even form and is superior in visibility.;COPYRIGHT: (C)2000,JPO