An ultrasonic horn used in, for instance, wire bonding having a structure for holding a capillary therein, the capillary holding structure including an external screw section which protrudes from the end surface of the horn and a spacer mount which is larger in diameter than the external screw section and formed on the root portion of the external screw section. A ring-form spacer is mounted on the spacer mount, and the spacer has a shape that prevents the rotation of the spacer on the spacer mount and is formed so that its vertically opposing end portions are positioned above and below the capillary attachment hole, and the length between the horizontally opposing end portions of the spacer is shorter than the length of the vertically opposing end portions. In addition, a tightening member, such as a nut, is screwed on the external screw section so that a ring-form pressing part which is formed on the tightening member presses only against the vertically opposing end portions of the spacer, thus holding the capillary on the horn.

An alignment apparatus is provided for ensuring proper positioning of a wire bonding capillary during installation of the wire bonding capillary onto the horn of a wire bonding machine. The apparatus ensures that the capillary is in a correct position relative to its longitudinal axis and is also in a desired rotational position with respect to the horn. The apparatus includes a first arm and a second arm which are movable toward each other to engage an outer surface of the horn thereby gripping the horn between the first and second arms. The apparatus also includes a support for holding the capillary. When the apparatus is properly positioned on the horn the support holds the capillary in a predetermined position in which the capillary is properly aligned with respect to the horn. A locking mechanism of the horn may then,be used to lock the capillary onto the horn.

A bump bonding apparatus comprising: a loader section that holds trays which accommodate semiconductor pellets and an unloader section that holds trays which accommodate semiconductor pellets to which bumps have been applied, the loader and unloader sections being provided next to each other on one side of a bonding stage; a buffer station and a supply and holding station provided so as to positionally correspond to the loader section and unloader section, respectively; a first pusher for sending trays from the loader section to the buffer station, a second pusher for sending trays from the supply and holding station to the unloader section, a third pusher for sending trays from the buffer station to the supply and holding station, and a pellet transfer mechanism for picking up a semiconductor pellet in the tray in the supply and holding station, transferring it to the bonding stages and then returning the semiconductor pellets to which bumps have been applied on the bonding stages back to the tray in which the semiconductor pellet has been accommodated.

The present invention concerns a self locking system for holding a wire bonding tool in a wire bonding transducer and comprises an unitary cam key rotatably mounted in a cam key aperture extending through an anti-node end of an ultrasonic transducer. A cam surface on the cam key is operable to lock a bonding tool mounted in a substantially vertical bonding tool aperture when rotated less than 360.degree. in said cam key aperture.

A transducer horn for holding a tool, such as a capillary, for a wire bonder has a pair of resilient arms which flex to clamp about a tool placed in a passage between the arms. The arms have free distal ends between which a wedge is inserted to open the passage to allow the tool to be inserted into, or removed from, the tool holder. The arms may be covered by protective walls, in which case an end wall is provided with an aperture to allow the wedge to access a slot between the arms.