The Microelectronic Wire Bond: Past, Present, and Future

Since its very inception, the microelectronic wire bond has been the dominate form of first-level interconnection (chip to package or substrate). Wire bonds account for over 80% of first-level chip interconnections made by the microelectronic industry each year. Wire bonding is reliable, flexible, and low cost when compared to other forms of first-level interconnections. In this article a brief discussion of wire bonding is presented along with bond formation fundamentals. Aspects of wire bond reliability will be explored in conjunction with methods of wire bond testing. Particular attention is given to fine pitch bonding, bonding to stacked die, higher frequency bonding, ball bonding with copper wire, and advanced bond testing methods.