| 摘要 |
PURPOSE:To surely and easily detect disconnection of a wire by detecting a shift between a spool of a bonding wire and a capillary chip. CONSTITUTION:A wire shift sensor unit 13a is provided between the spool 7 and capillary chip 6, a wire shift voltage responding to an output signal fed from the sensor is detected by a wire shift detection voltage generating unit 13b to detect the disconnection of the wire. For this detection, the wire is adapted to be moved in a bias magnetic field formed by the first magnet and second magnet, an eddy current flows inside the wire according to the moving speed and effects appearance of a bias in the bias field, so that a change of a resistance value of a bridge circuit is enough to be detected from the bias appearing in the bias field. Thus, the detection of the disconnection can surely and easily be conducted without a flow of the current through the wire or an influence by the outer induction. |
