| 摘要 |
<p>PROBLEM TO BE SOLVED: To perform uniform surface treatment for working at the periphery which is not weak. SOLUTION: Luminous flux from a laser device is condensed into a rectangular aperture 2, by using a spherical mirror or a convex lens. The optical component of a first axis in a direction perpendicular to the optical path of an image of the rectangular aperture 2 is projected on a board surface with a first cylindrical concave mirror. Rear laser luminous flux of the first cylindrical concave mirror is divided into two luminous fluxes with a grid mirror 4. A second and a third cylindrical concave mirror 5, 6, which project the optical components of a second axis in a direction perpendicular to the optical path of the image of the rectangular aperture 2 on the board surface are arranged in both the luminous fluxes. The luminous fluxes are reflected with the second cylindrical concave mirror 5, symmetrically inclined at least 30 deg. from the perpendicular line of the board, condensed on a common rectangular region on the board, and made to interfere with each other to generate a strip pattern having pitches of at most the wavelength of the luminous flux. Thereby the surface of an insulating resin layer is etched, and stripe patterns are etched in a plurality of positions of the insulating resin by moving the board with a sending mechanism.</p> |
