The wire bonders are available to use in the backend bay of the clean room. The West-Bond model has been set up as an ultrasonic 45-degree wedge bonder. The ultrasonic energy attaches a 0.001" aluminum wire at room temperature. The wire is clamped and threaded diagonally under the bonding wedge, allowing independent feeding action but requiring front-to-back bonding direction. The tool is guided manually by the operator using hand/eye reference to bond targets and elevations.

Wire Ultrasonic Wedge Bonding is an established assembly interconnect technique in the semiconductor industry. Commonly referred to as Wedge Bonding, this technique connects the semiconductor chip to the external leads. The physical connection is accomplished via a gold or aluminum wire, ranging from .0005"/13µm to .003"/75µm in diameter. The wire material used is critical for wedge material selection and design due to the different material properties of aluminum versus gold wire. Bonding has three basic methods: ultrasonic, thermocompression and thermosonic. The ultrasonic method uses ultrasonic energy to attach the wire. Thermocompression uses heat and pressure to attach the wire. For thermosonic, the wire is fed through a capillary; an electrical spark melts the tip to form a ball; and then the capillary moves downward to touch the bonding pad. After pressure, the capillary moves upward release some wire and then positioned to make the second bond.

For additional information about the West-Bond 7476D Wire Bonder, please contact James Vichiconti at jv2534@columbia.edu or email the clean room staff at cnicleanroom@columbia.edu.