Wire bonding is an important part of modern electronics. It connects semiconductor parts to form complete and working modules. Homes, cars, spacecraft and many other things depend on circuitry with many small conductors interconnected. Most of these connections use either ball bond or wedge bond methods. Let’s check out each method to show you the different applications.
What Are Ball Bonds?
When you need to connect computer chips to circuitry, tiny gold wires work best, and ball bonding is the most common technique. Gold wire is best because the oxides formed during the process don’t interfere with bonding. Copper wiring is sometimes used, but it needs nitrogen gas to prevent copper oxide material from forming.
Many companies choose copper for the ball bond method because it is a cost-effective alternative and a superior electrical conductor. Also, copper is harder and less likely to damage computer chips, than gold.
To create a ball bond, electricity heats one wire end, forming a ball. The ball presses against the contact surface while a machine stretches out the wire and presses it tightly against the next surface, applying heat and breaking the wire in the wire bonding process. This method produces as many as 12 wires a second.
Wedge Bonds
Wedge bonding uses heat, pressure, and ultrasound. It’s often used with aluminum wire and uses lower temperatures than ball bonding. The welding process produces a wedge shape instead of a ball. Even though the process is slower than ball bonding, wedges are smaller than balls and allow for finer welding points. A typical wedge bond process welds about six wires per second.
Which is the Best Wire Bonding Method?
Both wedge and ball bonds are highly effective. If you want the fastest method for bonding gold wires, choose ball bonds. For aluminum bonding and welding fine points, go with wedge bonding.
