US Patent 7780056 Horn attachment arm

A horn attachment arm for a bonding apparatus that performs high speed bonding with high accuracy to a large sized workpiece is provided. The horn attachment arm includes a fixing bracket fixed to a moveable member of a driving motor and a ultrasonic horn attaching bracket for attaching an ultrasonic horn on a tip end side to be fixed by being sandwiched between flat plates made of carbon fiber reinforced plastic. A flat plate space keeping member is attached between the flat plates so as to extend between the brackets. Flanges of the brackets and the longitudinal structure member are fixed to respective flat plates using a screw and an adhesive agent. The carbon fiber reinforced plastic that constitutes the flat plates has a greater number of reinforced fibers in a longitudinal direction than in a width direction, and is high in strength and rigidity in the longitudinal direction.