Ball forming device, wire-bonding apparatus, and ball formation method
A ball forming device 50 for forming a ball 43 at a tip of a wire 42 by producing discharge between a torch electrode 48 and the tip of the wire 42 , the device includes: a current supply unit 54 configured to supply a ball-forming current between the torch electrode 48 and the tip of the wire 42 ; and a current control unit 57 configured to control the current supply unit 54 , so that a signal of the ball-forming current for a predetermined period includes a first period in which the signal takes a predetermined current value and a second period including a triangle wave. With this, it is possible to provide a ball forming device, a wire-bonding apparatus, and a ball formation method that are capable of suppressing formation of deformed balls.
1. A ball forming device for forming a ball at a tip of a wire by producing discharge between an electrode and the tip of the wire, the device comprising:
a current supply unit configured to supply a ball-forming current between the electrode and the tip of the wire;
a discharge detection unit configured to detect a discharge between the electrode and the tip of the wire; and
a current control unit, which controls the ball-forming current to a predetermined value to form the ball with a predetermined diameter at the tip of the wire after the discharge is detected, and controls to produce a plurality of triangle waves in the ball-forming current to flatten a surface of the ball after the ball with the predetermined diameter is formed.
2. The ball forming device according to claim 1 , wherein
the second period includes a triangle wave having predetermined amplitude.
3. The ball forming device according to claim 1 , wherein
the second period includes a triangle wave whose current value gradually decreases over time.
4. The ball forming device according to claim 2 , wherein
the second period includes a triangle wave whose current value gradually decreases over time.
5. The ball forming device according to claim 1 , wherein
the wire is constituted from a material of a plurality of metals.
6. A wire-bonding apparatus comprising:
the ball forming device according to claim 1 .
7. A ball formation method of forming a ball at a tip of a wire by producing discharge between an electrode and the tip of the wire, the method comprising:
a current supply step of supplying a ball-forming current between the electrode and the tip of the wire,
a discharge detection step of detecting a discharge between the electrode and the tip of the wire,
a step of controlling the ball-forming current to a predetermined value to form the ball with a predetermined diameter at the tip of the wire after the discharge is detected, and
a step of producing a plurality of triangle waves in the ball-forming current to flatten a surface of the ball after the ball with the predetermined diameter is formed.