| 摘要 |
PURPOSE:To automatically detect defects in wire bonding with high accuracy without depending upon visual observation by applying a light beam between a projector and a receptor and relatively displacing the light beam with respect to a wire in the direction crossing the direction of the stretching of the wire. CONSTITUTION:Light beams L are applied between projector-receptor 13, 14 disposed in the vertical direction of clearances (m) among the land section 2 and leads 6, 7 of a lead frame 1, thus detecting defective bonding. That is, light beams L are displaced in parallel only by a specified stroke at every one semiconductor pellet 3 along the longitudinal direction while being received by the receptor 14. Light beams L are interrupted by wires 8, 9, 9 by the scanning of the light beams L, output signals P from the receptor 14 as shown in the figure are acquired, and the number of the output signals is counted. Accordingly, the presence of the wires having small wire diameters and array pitches can positively be detected automatically without depending upon the visual observation of an operator.
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