Patent ID: 7297472

Claim:
A method for processing a photoresist-coated board comprising steps of intermittently projecting a pulse-like laser beam onto a photosensitive material layer on or above a light absorption layer provided in the photoresist-coated board to expose the photosensitive material layer to the laser beam, and developing the photosensitive material layer, thereby forming a raised and depressed pattern on the photosensitive material layer, wherein when a length of a depressed portion or a projecting portion of the raised and depressed pattern is shorter than a predetermined length, a duty ratio of the pulse-like laser beam is varied in accordance with the length of the depressed portion or the projecting portion of the raised and depressed pattern, and when the length of the depressed portion or the projecting portion of the raised and depressed pattern is equal to or longer than the predetermined length, the duty ratio of the pulse-like laser beam is kept constant independently of the length of the depressed portion or the projecting portion of the raised and depressed pattern, thereby exposing the photosensitive material layer to the laser beam.