Abstract: A number of techniques and substrate arrangements are described that working individually and in common have been found to significantly improve the environmental resistance of the resulting package. In one aspect, conductive pads (referred to herein as landing pads) on the top surface of a substrate are slightly undercut. This permits molding material applied during later packaging to flow into the undercut regions to help improve adhesion between the substrate and the molding material. In another aspect, metallic die attach pads formed on the substrate are patterned to provide better adhesion between the substrate and a solder mask that covers the die attach pads. More specifically, the metallic die attach pads are patterned to have a number of opening defined therein that leave corresponding portions of the substrate exposed.