iNEMI Issues Recommendations for Managing Lead-Free Solder Alloys

iNEMI has outlined a set of key approaches to help the electronics industry respond to the many issues and challenges emerging in the manufacturing process as a result of numerous lead-free solder alloy options.

Sally Cole Johnson, Contributing Editor -- Semiconductor International, 7/10/2008 8:31:00 AM

There are serious challenges associated with managing multiple lead-free solder alloys — in terms of both manufacturing and product performance. To help the electronics industry deal with this growing issue, the International Electronics Manufacturing Initiative (iNEMI, Herndon, Va.), an industry-led consortium focused on identifying and closing technology gaps, has outlined a set of key approaches to manage lead-free alloy alternatives. Their recommendations support guidelines developed by the EMS Forum (a group with representatives from Celestica [Toronto, Canada], Flextronics [Singapore], Jabil [St. Petersburg, Fla.], Plexus [Neenah, Wis.] and Sanmina-SCI [San Jose]).

Managing lead-free solder alloy alternatives is a complex, critical issue facing the industry, noted Dongkai Shangguan, Flextronics’ vice president of technology, chair of the iNEMI board assembly roadmap and coordinator of the EMS Forum. “The global industry must take a methodical and holistic approach, balancing the need for innovation and considerations for cost, performance, processes and logistics, as well as standardization,” he said.

Many questions remain regarding the processing parameters, reliability and performance of lead-free solder alloys. SAC 305 and 405 are the most prevalent alloys to date, but there are concerns about using these alloys, for example, in wave soldering, selective soldering, hand soldering and rework.

“The industry’s experience with lead-free processing is still in its infancy, and much remains to be learned. It is inevitable that industry will continue to innovate and develop new solder formulations and fluxes as our experience with lead-free grows,” said Jim McElroy, iNEMI’s CEO. “The use of multiple alloys, however, poses several challenges in the manufacturing process, and industry needs a way to manage these challenges and limit their impact.”

To manage the use of multiple solder alloys, iNEMI is recommending the following five approaches:

• Drive the convergence on a minimal number of lead-free alloys that will satisfy most application requirements within the electronics industry
• Develop an industry-standard methodology to assess the overall process and technical impact of new alloys
• Establish performance guidelines when considering the use of alternative alloys because manufacturing considerations must be fully understood
• Update standards as changes in alloy formulations and related manufacturing process parameters evolve
• Identify and differentiate alloys by using unique markings to minimize manufacturing errors in environments dealing with multiple alloy formulations

“While there are generally very good reasons to move to alternate lead-free alloys, both at the component level and in printed circuit assembly, the potential impact on manufacturing processes can be quite severe,” said Peter Tomaiuolo, director of corporate technology at Celestica. “It is critical that customers, manufacturers and suppliers have an open dialogue to fully understand these impacts so that the quality and reliability of the end product is not compromised.”

Optimizing the reliability of SAC solder joints without creating a multitude of component-centric solutions is important to Intel (Santa Clara, Calif.), according to Martin Rausch, general manager of SMTD at Intel. “We’re looking to iNEMI’s lead-free Alloy Alternatives Project to address this topic, because this issue can more effectively be addressed by the industry as a whole rather than on a company-by-company basis,” Rausch pointed out.

iNEMI’s full recommendations are available online.