Lead frame fabricating method and lead frame fabricating apparatus

摘要

PCT No. PCT/JP94/01292 Sec. 371 Date Apr. 3, 1995 Sec. 102(e) Date Apr. 3, 1995 PCT Filed Aug. 4, 1994A lead frame fabricating method and a lead frame fabricating apparatus are provided which can easily fabricate lead frames of fine pattern at a high speed, can improve dimensional accuracy and quality of the lead frames after the fabrication, and can realize mass-production at a lower cost. To this end, when cutting a metal plate 1101 by irradiation of a laser beam, a laser beam 1011 emitted in the form of pulses and having a circular section is converted by a beam section transformer 1020 into a laser beam 1012 having an elongate elliptic section. The section of the laser beam 1012 is rotated on its optical axis by a beam rotating device 1030 so that the lengthwise direction of the section of the laser beam 1012 is coincident with the lengthwise direction of each of inner leads 1013. An optical axis of a laser beam 1015 is revolved along each of concentric paths 161 to 174 around the original optical axis given when the laser beam 1011 is emitted. Alternatively, a laser beam 3011 emitted in the form of pulses and having a circular section is converted by a beam section transformer 3020 into a laser beam 3012 having an elongate elliptic section. The section of the laser beam 3012 is rotated on its optical axis by a beam rotating device 3030 so that the lengthwise direction of the section of the laser beam 3012 is coincident with the lengthwise direction of each of the inner leads 1013.