Bewertung des Korrosionsschutzes von Drahtbondverbindungen mittels Glob Top bei unterschiedlichen Umgebungsbedingungen

High reliability in electronics has to be guaranteed at worse environmental conditions. At the same time the tendency to smaller dimensions holds on. Under these circumstances the protection against corrosion plays an important role. Methods of accelerated testing are presented for COB devices under glob top. The degradation mechanisms under the influence of temperature and humidity are investigated. There are always different mechanisms superimposing. Galvanic corrosion and crevice corrosion is only working at high humidity levels and the existence of free ions. High temperature leads to the formation of intermetallics. Thermal shock is connected with mechanical stress. Both may initiate the formation of cracks. It can be stated that as a result of a careful selection of materials and technology a sufficient reliability level is reached.