Lead-free ... Are You Ready?
02/01/2000
Mark Diorio
Word has it that a prominent Silicon Valley-based semiconductor company president decreed to his packaging group that Japan`s requirement on lead-free electronic assemblies and the elimination of lead from the external solder on an integrated circuit (IC) package by the first quarter of 2001 (1Q01) will not be an impediment to his company`s shipment into Japan. In other words, "Packaging engineering, don`t let lead-free be another obstacle between Japan and U.S. trade; make sure you have a fix!" While I am quite sure that this particular company will find a solution, the question for the U.S. packaging community is: Are we aware that some Japanese companies are imposing lead-free criteria on components as early as 1Q01, and will the U.S. packaging community have a solution in time?
While some may question this effort, it is to the U.S.` benefit to come up with a solution. As packaging engineers dedicated to the trade and advancement of the IC package, we can make an effort to remove lead. And if our somewhat insignificant contribution will aid the world environment, then we should make that effort.
There are several lead-free efforts under way by a variety of industry associations. The most significant in the U.S. appears to be the National Electronics Manufacturing Initiative (NEMI), which, combined with the IPC, is initiating efforts to aid North American companies in producing lead-free electronic products by 2001. It appears that much of its work is targeted appropriately because members are attempting to foster cooperation between various communities of electronic assemblies (components, boards, equipment, materials) and are intending to modify and/or develop the appropriate JEDEC or IPC standards for lead-free electronics manufacturing. However, it is my opinion that there is not a strong enough initiative from the semiconductor packaging groups to support the lead-free effort. It appears that companies are just waiting for someone else to give them a lead-free solution for their packages.
Most lead-free efforts under consideration require manufacturing processing temperatures up to 260°C. Even if someone were to give us a lead-free material solution, do we know and understand how this temperature level will affect components? What will happen to the die? What will happen to the package? Have we analyzed the package stress and included the CTE analysis with both alpha 1 and alpha 2 values? What happens to the flame retardant in the mold compound at the elevated processing temperatures? And how about visual inspection criteria as it pertains to the filet height and coverage? The point is that, even if there was a lead-free solution, we still need to know how it truly affects packages. There are many questions that need to be answered as they pertain to package performance criteria; the answers to these questions, I can assure you, have not been thought about, let alone will come from any one consortium, task force or initiative.
One group that appeared ready to meet the lead-free packaging challenge was an effort briefly led by San Jose State University in cooperation with Silicon Valley-based semiconductor companies. While the university is currently struggling to maintain the effort because of an apparent lack of resources, this is the type of lead-free effort needed for the packaging community, as the companies and individuals involved in the project - senior level packaging engineers highly experienced in such technical initiatives and who possess a thorough understanding of the package and its environment - came with high credibility. However, until the university can determine its involvement, this effort may not realize its potential and provide the results required to achieve a lead-free package success. Similar efforts, if they exist, can also achieve good results, but the point is that such efforts require active participation from the packaging community and those individuals involved must possess a full technical understanding of the task at hand.
So what are we to do? Sit back and wait for a lead-free solution to present itself, while running the risk of U.S. ICs being blocked from shipping into Japan? Or do we, as packaging engineers, take a more active posture to eliminate lead from the external package? At the end of the day, packaging should be part of the solution, not part of the problem.
MARK DiORIO, chief operating officer, can be contacted at MTBSolutions Inc., 2685 Marine Way, Suite 1220, Mountain View, CA 94043; 650-960-3203; E-mail: [email protected].