Environmental regulations are forcing the elimination of lead (Pb) from electronic equipment. Solders containing lead have been the standard in printed circuit assembly processes. Lead-free solders currently being used and developed for printed circuit assembly require higher processing temperatures that can degrade the base materials commonly used in printed circuits, resulting in decreased long-term reliability. Following a brief discussion of the regulations and lead-free materials and processes, this paper will discuss several base material properties and present test data that highlights the importance of specific properties that should be considered when selecting materials for lead-free applications.