Wire bonder transducer arrangement and method

A wire bonder for electrically coupling an integrated circuit die to associated wiring traces, the wire bonder comprising:

• first and second ultrasonic transducers;
• a capillary holder for supporting a capillary having a bonding wire suitable for electrically connecting an integrated circuit die pad to a lead on an associate wiring trace, the capillary holder being secured to the first and second transducers such that actuation of either of said transducers will cause movement of the capillary supported by the capillary holder;
• and
• signal generator means for applying drive signals to the transducers to mechanically bond a bonding wire to at least one of an integrated circuit die pad and a wiring trace, the signal generator means being arranged to permit independent actuation of the transducers at frequencies suitable for ultrasonic welding, the signal generator means including a controller for controlling the timing of the drive signals whereby the direction of ultrasonic energy applied during welding may be varied by adjusting the relative timing of actuation of the first and second transducers, wherein the drive signals transmitted to the first and second transducers are derived from a common source and the controller is arranged to adjust the phase of the drive signals.

A wire bonder for electrically coupling an integrated circuit die to associated wiring traces in a semiconductor package, the wire bonder comprising:

• a transducer arrangement;
• a capillary holder for supporting a bonding wire suitable for electrically connecting an integrated circuit die pad to a lead on an associate wiring trace, the capillary holder being secured to the transducer arrangement such that actuation of the transducer arrangement will cause movement of the capillary holder;
• and
• a signal generator for applying drive signals to the transducers at frequencies suitable for ultrasonic welding to ultrasonically weld a bonding wire between an integrated circuit die pad and a wiring trace lead, the signal generator being arranged to permit actuation of the transducer arrangement in a manner that permits non-linear variation of the direction of ultrasonic energy applied during welding of different bonding wires in a semiconductor package to provide good welds between the bonding wires and their associated wiring traces.

A method of wire bonding an integrated circuit to leads of associated wiring traces, the method comprising the steps of:

• bonding a first end of a first bonding wire to a first die pad;
• ultrasonically welding a second end of the first bonding wire to a lead of an associated first trace, the direction of the ultrasonic energy used for welding the second end of the first bonding wire to the lead of the associated first trace defining a first pattern;
• bonding a first end of a second bonding wire to a second die pad;
• and
• ultrasonically welding a second end of the second bonding wire to a lead of an associated second trace, the direction of the ultrasonic energy used for welding the second end of the second bonding wire to the lead of the associated second trace defining a second pattern that is non-linear and varies in direction from said first pattern.