| 摘要 |
PURPOSE:To avoid the influence of a residual magnetic force when an electromagnet is deenergized during a bonding operation by forming the core of the electromagnet and an attracting plate of an iron-nickel magnetic alloy. CONSTITUTION:An electromagnet 17 is energized when a capillary 9 is moved down and up to engage the holder 6 of a bonding horn 5 with a bonding driving arm 3 to prevent a vibration during that time. It is deenergized at first and second bonding times to transmit the force of a tensile coiled spring 23 as a pressing force. The core 19 of the electromagnet 17 and an attracting plate 22 are formed of iron-nickel magnetic alloy, and particularly an iron-nickel magnetic alloy which contains 45% or more of nickel. Thus, when the electromagnetic coil 20 of the electromagnet 17 is energized, the core 19 and the plate 22 are attracted magnetically strongly, but at deenergizing time the residual magnetism is extremely small, and only the force of the spring 23 is accurately transmitted as pressing force at first and second bonding times. |
