Tag Archives: Richard Coyle

RoHS: 10 Years After

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Every so often, I get to work on a project that I find utterly rewarding.

The RoHS article in this month’s issue of PCD&F/Circuits Assembly was one such project.

Titled “Was RoHS Worth It?“, it attempts to recap the chaos and angst that preceded the ban of lead in Europe (and the de facto phase outs elsewhere). It a real eye-opener how even the most hardened anti-RoHS researchers came around to seeing value from the experience. There was broad agreement, even among those who felt the fears over lead were overblown, that much was learned from the process, not the least of which is that no matter how much we have invested in one technology, there are likely others that are better.

As Dr. Iver Anderson told me, “You could say RoHS banning electronics really is a glimpse of the future. Because it won’t be the last time.”

To me, that quote distills in two sentences what I hope to achieve from embarking on this retrospective: a record that the researchers and engineers of the future can use as a benchmark for future broad-based transitions.

I am grateful to Karl Seelig, Jim McElroy, Paul Vianco, Dr. Carol Handwerker, Tetsuro Nishimura, Kay Nimmo, Iver Anderson, Dave Hillman and Dr. Richard Coyle for their invaluable help.

Happy reading!

 

On Pb-Free Reliability and its Doubters

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I was at SMTAI (Surface Mount Technology Association International) in late September. As mentioned, I chaired a session on Alternative Alloys. At this session, Greg Henshall presented a paper on the Low Silver BGA Sphere Metallurgy Project. This paper was a collaborative effort of six companies. In addition, Richard Coyle presented an overview of the work of three companies titled “The Effect of Silver Content on the Solder Joint Reliability of a Pb-free PBGA Package.” Both projects evaluated lead-free thermal cycle reliability as a function of silver content and compared the results to SnPb reliability.

Both papers concluded that as far as thermal cycle reliability is concerned

SnPb < SAC105 < SAC305 < SAC405

Coyle’s paper summed it best:

Each of the SAC alloys outperformed the SnPb eutectic alloy in every test, including the long, 60 min. dwell time test. This tends to diminish the argument that SAC is less reliable than SnPb. (See Coyle’s figure. Data curves to the right are more reliable.)

Henshall’s paper also showed that the addition of dopants, to improve shock resistance, in SAC105 does not reduce thermal cycle life.

So, it appears, at this time, that, from a thermal cycle and drop shock perspective, it is looking more and more like SAC-based solders out perform SnPb solders in these two reliability arenas.

At the end of the session a noted lead-free curmudgeon came over to introduce himself.  We have had a jovial disagreement on several blogs, etc., in the past re: lead-free status and issues, but had not met in person. I should mention that this person is a college graduate, a former technical leader at several influential technological companies, and he owns a PE license. I asked him what he now thought about lead-free reliability after hearing the talks. He claimed that he is a little less likely to think that Pbfree reliability is a disaster. He still refuses to purchase lead-free products. He buys old units (pre-2006) on eBay.

I mentioned that over $2 trillion of electronics has been placed in the field since 2006 with no unusual reliability issues. I then went on to say that a RoHS-compliant product is much more likely to fail due to a non-RoHS related issue. He did not disagree. So then I asked him why he won’t use RoHS compliant electronics. His answer: “I just don’t trust them.”

Cheers,

Dr. Ron