BALL FORMING METHOD IN WIRE BONDING

• Main Authors: SAKAMOTO HIROSHI, TAKAO KOICHI, YOSHIKAWA MAMORU
• Format: Patent
• Language: English
• Published: 18.05.1990
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; SEMICONDUCTOR DEVICES

PURPOSE:To easily form uniform balls by a simple constitution, and improve the reliability of a wire bonder by generating discharge between wire and a circular hole electrode surrounding a wire tail. CONSTITUTION:A wire tail 1 of length l protrudes from a capillary tool 2. A circular hole electrode 3 has a hole whose diameter is a little larger than the outer diameter of the tool 2. By a high voltage, discharge is generated between the tip of the wire tail 1 and the inner wall 3a of the electrode 3. A uniform ball 4 is formed by the discharge. Even when the length, l1'<l, l1''>l of the wire tail changes, excellent discharge generates. When the wire tail 1 is bent, the gaps l2', l2'' between an inner wall 3a and the wire tail become l2'<l2, l2''<l2, where l2 is a gap length when the bend is not present, and erroneous generation of discharge can be prevented. Thereby, uniform wire balls are easily formed by a simple constitution, and the reliability of a wire bonder is increased.