| 摘要 |
PURPOSE:To lessen the spreading of a gold ball in lateral direction when a press-welding is performed as well as to reduce the area of bonding pad by a method wherein a recessed part is provided at the tip of a capillary, and a thermo-press welding is performed on the bonding pad and the gold ball in the state wherein a part of the gold ball is buried in the recessed part. CONSTITUTION:A gold wire 4 of prescribed length is protruded at the tip of a capillary 1 when a bonding work is performed, and the tip part of said gold wire 4 is formed into a ball-like lump 5 (gold ball) by discharging electricity, for example. Load is applied on the gold ball 5 through the capillary 1, the ball 5 plastically flows on the surface of bonding, it is transformed and spreads out on a bonding pad 7. The oxide film on the surface of the bonding pad 7, which is the objective substance of bonding, falls off by the drift energy of the gold ball generated at that time, and the newly appeared surfaces are jointed together. As the greater part of the gold ball 5 is placed in the recessed part 3 provided at the tip part of the capillary 1, load is applied by the tip part of the capillary 1, thereby enabling to reduce the volume of the gold ball 5 in the state of plastic flow. As a result, the control of bonding area can be made possible. |
