Orthodyne Electronics Corporation

Hal W Smith, Jr

Michael C Smith

An improved ultrasonic wire bonding method and apparatus is disclosed having a wire delivery conduit for removing coil set in the wire through a serpentine movement prior to being bonded, which also provides sufficient drag to prevent displacement as the bonder with the wire is being moved from one location to another, and which orients the wire to said bonding tool end. An improved wire cutter moves independently of the wire bonding tool and is directly connected to the main Z positioning movement of said wire bonder so that the wire bonding tool and the cutter can move independently during the process. The wire bonding tool can be biased by a magnetic bias with an armature connected to the wire bonding tool. The wire bonding apparatus and the method provide a loop in the wire between first and second bonds by forming an arcuate bend in the wire as it moves away from the first point of bonding. After a second bond, the wire is partially cut by a cutter that moves relative to the bonding tool to partially cut the wire which is then severed by pulling the bonding tool and cleating the wire in the end thereof.

Ultrasonic wire bonder wire formation and cutter system

The specification sets forth an ultrasonic wire bonding system for bonding wire to an underlying electronic circuit or terminal. The system incorporates a bonding tool connected to a transducer which causes the bonding tool to ultrasonically vibrate and when impressed against a wire lying thereunder, bond said wire to an underlying electronic circuit. The transducer is driven by a generator which generates either a constant current or constant voltage to the transducer while it is bonding. The constant current mode accommodates thick films and stitch bonding which require substantially more force, while the constant voltage mode provides for thin films and ball bonding which requires substantially less ultrasonic force. As a consequence, the generator provides for the foregoing dual mode so as to optimize the bonding characteristics between the two respective bonds that are provided by this invention and is controlled by a host computer, a digital to analog converter (DAC) and a phase detector connected to a reactance modulator with a limiter and a synchronous detector through a power amplifier to a respective transducer that is to be driven in either the constant current or constant voltage mode.

Dual mode ultrasonic generator in a wire bonding apparatus

The following specification discloses a touchdown sensor for ultrasonic wire bonding devices. Such ultrasonic wire bonding devices are used for purposes of bonding wires to integrated circuits, package terminations, hybrids, and discrete semiconductor devices. The devices entail the utilization of a transducer that operates in a series resonant mode. The means of exciting the resonant mode is through an electrical signal imparted thereto, so that a tool attached to the transducer can then impart an ultrasonic bond to a wire with which it is placed in contact. The tool attached to the transducer is lowered by the device to a discrete location. The point of contact is monitored by sensing an increased impedance by contact of the tool and dampening of the transducer's resonant mode. This increased impedance is read by means of producing a voltage proportional to transducer current and determining when it has decreased below a previously set reference voltage. A comparator then makes a comparison of the reference voltage with respect to the decreased voltage and signals a control microprocessor to stop the device. This is done by preventing a motor from carrying the tool farther after it has made contact with the work.

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Costa Mesa, CA, United States of America

Hal W Smith, Jr