| 摘要 |
PURPOSE:To detect a defective product of lead frame, by a method wherein a scanning laser beam is made to hit a lead frame of a film carrier and the time during which the beam is transmitted through the frame or shielded thereby is determined to detect the shape of the frame. CONSTITUTION:A laser beam 13a is radiated from a laser unit 13 and reflected with a mirror 96 to hit a conical mirror 7. Beam is reflected with the conical mirror 7 to scan a lead frame 3 in a circle. A rotating shaft 4a is turned with a motor 4 to move a moving stage 5 and then, the motor 4 is shifted to change the size of the circle of the scanning beam. then, the beam is shielded by the frame 3 or transmitted between leads. Subsequently, the beam is converted 11 into electricity from light and the measure time of the beam equivalent to a lead width and lead interval is measured with a processing circuit 12 to determined a size of the shape for the lead width and lead interval. Thus, the lead width and interval are detected by the light transmitted light and light shielded thereby enabling quick detection of a defective product.
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