PURPOSE: To increase a connection strength across a wire by optimizing the bonding conditions separately by leads parallel with the oscillation direction of ultrasonic waves and by leads perpendicular to the direction.
CONSTITUTION: Concerning the bonding on the lead frame (3) side, the side face of a coated wire 12 is pressed down onto a lead 3b with a first oscillation. Then, the bonding is conducted by the two-stage ultrasonic oscillation method by which the coating is broken by ultrasonic oscillation and then the wire and the lead are bonded with a second oscillation. When bonding the coated wire 12 on the lead frame (3) side, the bonding conditions for the first and second oscillation processes are controlled separately by the leads 3b facing the oscillation Y direction of ultrasonic waves and by the leads 3b facing the X direction to cross at right angles with the Y direction, out the leads 3b formed on the lead frame 3. By this method, the tensile strengths of the wires bonded onto the leads facing the Y direction is increased and thereby there is no difference in tensile strength of the leads between in the X and Y directions.
OKIKAWA SUSUMU
MIKINO HIROSHI
TANIMOTO MICHIO
TAKASHIMA KAZUHISA
TAKASUGI NOBUHIRO
HITACHI TOKYO ELECTRONICS
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