Laser processing apparatus and electronic device manufacturing method

An electronic device manufacturing method comprising:

• producing an interposer by laser processing an interposer substrate with a laser processing apparatus, the laser processing apparatus performing laser processing by irradiating a workpiece with a laser beam output from a laser apparatus and including
• a mask disposed on an optical path of the laser beam and provided with an opening,
• an illumination optical system configured to focus the laser beam to illuminate the opening,
• a projection optical system configured to form an image of the opening on a surface of the workpiece,
• a beam splitter disposed between the illumination optical system and the mask and configured to branch the laser beam,
• an image sensor disposed on an optical path of the laser beam branched by the beam splitter and configured to generate an image including a focal image of the laser beam on the mask, and
• a processor configured to correct a focal position of the laser beam relative to the opening by controlling the illumination optical system based on the generated image;
• coupling and electrically connecting the interposer and an integrated circuit chip to each other;
• and
• coupling and electrically connecting the interposer and a circuit substrate to each other.