Abstract: A composite sheet whose product price can be reduced with a smaller number of manufacturing processes. A laser oscillator outputs a pulsed beam at a frequency f. A mask shapes the outer shape of the beam into a triangular, quadrangular or hexagonal shape. N pieces of time-sharing means time-share the beam to form N beams having a frequency f/N. N pairs of positioning means position the time-shared beams. A condensing lens condenses the beams. A rotating drum displaces a workpiece. A control means controls the time-sharing means, the N pairs of positioning means and a pedestal. The N pairs of positioning means are positioned to irradiate predetermined positions with the beams. The pedestal is moved. The time-sharing means are thereupon operated in predetermined order. The workpiece is machined to make holes whose outer shapes depend on the mask so that distances between sides of adjacent holes are equal to one another.

Abstract: A method and an apparatus for perforating a printed circuit board are provided so that the processing efficiency and the board densification can be improved. In test processing, a conductor layer 50i is irradiated with a pulsed laser beam 4a whose energy density is set at a value high enough to process the conductor layer 50i while emission 23a from a processed portion is monitored. Thus, the number of pulses of irradiation required for processing a window in the conductor layer 50i is obtained. An insulating layer 51i is irradiated with a pulsed laser beam 5a whose energy density is set at a value high enough to process the insulating layer 51i but low enough not to process a conductor layer 50i+1 under the insulating layer 51i. Thus, the number of pulses of irradiation required for processing a window in the insulating layer 51i is obtained.

Abstract: In a method of and an apparatus for drilling a hole in a workpiece, a pressure foot associated with a drill is moved into contact with the workpiece, and a drill bit associated with the drill is moved from a drill-starting position into the workpiece, toward the drill-starting position and again into the workpiece while maintaining the pressure foot in constant contact with the workpiece. The drill is reciprocally fed by a plurality of times under the pressure of the pressure foot acting upon the printed circuit board. In either of the method and the apparatus, a hole with a high aspect ratio can be formed in a workpiece made from a thin, flexible material.

Abstract: An apparatus for drilling a hole in a workpiece such as, for example, a printed circuit board wherein a pressure foot, associated with a drill, is moved into a position to exert a pressure on the workpiece. A drill bit associated with the drill is moved with respect to the workpiece, and an arrangement is provided for controlling the operations of the pressure foot and the drill bit in such a manner so as to move the drill bit from a drill starting position into the workpiece, then toward the drill starting position and again into the workpiece while maintaining the pressure exerted on the workpiece by the pressure foot.

Abstract: In a method of drilling a printed circuit board according to the present invention, an entry feed rate at which a drill is fed into the printed circuit boards during the initial stage of drilling is made slightly smaller than a drilling feed rate at which the drill is fed while it is drilling a hole through the printed circuit boards, so as to enhance the accuracy at which holes are located. One drilling operation includes a plurality of drilling feeds of the drill, and pulled-out positions of the drill which are reached by the drill between adjacent drilling feed rate are set within a range in which the pressure of a pressure foot is effective. This can prevent the stacked printed circuit boards from shifting and increase the accuracy at which the holes are located.