The Solutions of Resistive Ball Bond Failure in Ultra Fine Pitch Wire Bonding

In an ultra fine pitch (UFP) wire bonding process, understanding inter-metallic growth and its effect on package reliability are challenging areas. In most cases, eventual resistive ball bond failure is a challenge to the ultra fine pitch packaging. This paper presents an innovative approach to the wire bonding process, tools and material set to enable great performance in reliability packaging. The process also introduces a new, superior 3N gold wire in order to slow down the inter-metallic (IMC) growth to prevent the resistive ball bond failure at earlier stressing stage. A series of evaluations were conducted to establish optimal wire bonding process with good package reliability on different devices. The new material set and process has been proven through production assembly over ten months without any major issues.