Improvement of Moisture Resistance by Ion-Exchange Process

To improve the moisture resistance after soldering heat stress for SMD(Surface Mount Device), a new approach introducing the "Ion-exchange process" was succesfully tried out. In this approach, ion-exchanging material(usually called "ion-trap") is added to the molding compound substituting the highly active impurity+ ions+ in the compound by weak ones(ex. Cl- → OH-, Na+ → H+). By applying this process, the lifetime for both cathodic and Al pad corrosion becomes 1.5~3 times longer for the epoxy compounds tested.