A Comparison Study of the Bondability and Reliability Performance of Au Bonding Wires with Different Dopant Levels

Over 90% of all interconnection methods in the semiconductor industry are using gold bonding wire. As the industry migrates into smaller unit size for electronic products, thinner wires are required. The general lower break load and decreased reliability of small wires drives the need for stronger and higher dopant concentration wires. This has prompted a market focus on 2N and 3N wires. In this study, 2N and 3N wires of similar dopants are compared based on both bondability and reliability. Studies indicate that 3N wires display a larger 2^nd bond window, while 2N wires reveal a short tail that limits bonding. On the other hand, 2N wires show superior reliability performance with no ball lift up to 10,000 hrs at 175degC. For 3N wires, a significant numbers of ball lifts were observed at comparable condition.