Editing Kirkendall effect (section)

==Examples==

{{Expand section|Many examples exist beyond just metals. Adding a few would be good.|date=March 2024|small=no}}

In 1972, C. W. Horsting of the [[RCA Corporation]] published a paper which reported test results on the [[Reliability (statistics)|reliability]] of [[semiconductor devices]] in which the connections were made using [[aluminium]] wires [[ultrasonic welding|bonded ultrasonically]] to [[gold]]-plated posts. His paper demonstrated the importance of the Kirkendall effect in [[wire bonding]] technology, but also showed the significant contribution of any impurities present to the rate at which [[Precipitation (chemistry)|precipitation]] occurred at the wire bonds. Two of the important contaminants that have this effect, known as '''Horsting effect''' ('''Horsting voids''') are [[fluorine]] and [[chlorine]]. Both Kirkendall voids and Horsting voids are known causes of wire-bond fractures, though historically this cause is often confused with the purple-colored appearance of one of the five different [[gold–aluminium intermetallic]]s, commonly referred to as "purple plague" and less often "white plague".<ref>{{cite web |title=Contamination-Enhanced Growth of Au/Al Intermetallic and Horsting Voids |url=https://nepp.nasa.gov/index.cfm/20987 |work=NASA |access-date=28 April 2013}}</ref>