Alternatives of lead bearing solder alloys

Proposed legislation and regulation dealing with the use of lead in commercial products are the main driving forces in the search for lead-free solder replacements in printed circuit board assembly. Research into potential replacements for the use of lead-tin solder in surface mount applications has prompted examination of alternative interconnect materials which not only include lead-free solder alloys but also address the use of nonmetallic-based attachment systems. The author discusses the available free-lead substitutes with emphasis on performance considerations and current processing changes that might be warranted due to the use of alternative interconnected materials. The choice of a joining material will necessitate consideration and optimization of the entire assembly process, its individual constituents, and the resulting performance. A significant development effort will be required for joining material substitution to present assembly practices and successful implementation into electronic product manufacturing