| 摘要 |
PROBLEM TO BE SOLVED: To provide a ball bonding method which can cut a wire at a fixed position without moving a capillary along a complicated track. SOLUTION: A wire W is clamped by a clamp R, a torch T is put close to the tip of the wire W projecting from a capillary C, and discharge is caused between the tip of the wire W and torch T to form a ball WB stop of the wire W (a). The discharge is carried out for a time which is about 5 to 10 times as long as a discharge time for normal ball formation, more specifically, for about 0.02 to 0.05 seconds while the voltage is 2,000 to 4,000 V and the current is maintained 20 to 50 A on the condition that the wire W is a gold wire of about 0.02 to 0.05 mm wire diameter. Then the wire B is released by opening the clamp R, and the ball WB atop of the wire W is pressed against an electrode S, by lowering the capillary C to bond the ball WB to the electrode S (b). Then the wire W is clamped by closing the clamp R, the clamp R and capillary C are moved up, and the wire W is cut at the root part of the ball WB to form a bump (WB) on the electrode S (c). |
