Laser processing method

A laser processing method which is carried out by a laser apparatus comprising:

• an oscillator;
• a spatial filter comprising a first convex lens, a member having a pinhole portion, and a second convex lens on an optical axis of the laser beam from an oscillator;
• two galvano-mirrors;
• and an f.theta. lens, the method comprising:
• emitting a laser beam from the oscillator;
• focusing the laser beam by the first convex lens;
• removing non-focusing components in a peripheral portion of a focusing spot performed by the first convex lens by passing the laser beam which has passed through the first convex lens through the pinhole portion, a focal distance of the first convex lens being set so that a focusing diameter of the laser beam at the pinhole portion of the member is equal to or smaller than a focusing diameter of the laser beam which has passed through the f.theta. lens;
• restoring the laser beam which has passed through the pinhole portion into a parallel laser beam by the second convex lens:
• scanning the laser beam which has passed through the second convex lens by means of the two galvano-mirrors;
• focusing the scanned laser beam by means of the f.theta. lens on a work to execute processing of the work:
• and
• wherein a hole diameter of the pinhole portion of the member is set to 1 to 1.4 times as great as a diameter of the focusing spot at a focusing point of the first convex lens, while the focusing spot diameter of the laser beam focused by the first convex lens is a diameter of a portion at which laser beam intensity becomes 1/e.sup.2 of its peak intensity.

A laser processing method which is carried out by a laser apparatus comprising:

• an oscillator;
• a spatial filter comprising a first convex lens, a member having a pinhole portion, and a second convex lens on an optical axis of the laser beam from an oscillator;
• two galvano-mirrors;
• and an f.theta. lens, the method comprising:
• emitting a laser beam from the oscillator;
• focusing the laser beam by the first convex lens;
• removing non-focusing components in a peripheral portion of a focusing spot performed by the first convex lens by passing the laser beam which has passed through the first convex lens through the pinhole portion, a focal distance of the first convex lens being set so that a focusing diameter of the laser beam at the pinhole portion of the member is equal to or smaller than a focusing diameter of the laser;
• beam which has passed through the f.theta. lens;
• restoring the laser beam which has passed through the pinhole portion into a parallel laser beam by the second convex lens;
• scanning the laser beam which has passed through the second convex lens by means of the two;
• focusing the scanned laser beam by means of the f.theta. lens on a work to execute processing of the work;
• and
• between the restoring of the laser beam and the scanning of the laser beam, removing non-focusing components in a peripheral portion of the parallel laser beam formed by the second convex lens by passing the parallel laser beam through a circular aperture of a member arranged between the second convex lens and an entrance of the galvano-mirrors on an optical axis of the laser beam from the oscillator.

A laser processing method which is carried out by a laser apparatus comprising:

• an oscillator;
• two galvano-mirrors;
• an f.theta. lens;
• and a member having a circular aperture before an entrance of the galvano-mirrors on an optical axis of the laser beam from the oscillator, the method comprising:
• emitting a laser beam from the oscillator;
• removing non-focusing components in a peripheral portion of the laser beam from the oscillator by passing the laser beam which is emitted from the oscillator through the circular aperture;
• scanning the laser beam which has passed through the circular aperture by means of the two galvano-mirrors;
• focusing the scanned laser beam by means of the f.theta. lens on a work to execute processing of the work;
• and
• wherein a diameter of the circular opening of the aperture member is set to a diameter 1 to 1.5 times as great as a diameter of a portion at which intensity of the laser beam becomes 1/e.sup.2 of its peak intensity.