Loss of a Legend

Werner Engelmaier, a man I have known for 20 years, died Friday on a trip to Jordan.

News of his passing stunned and saddened me. Werner was a force: a man of unmistakable integrity, commitment, intelligence and fearlessness.

Werner had attained guru status before I even had entered the industry. In the mid 1990s, while on the technical staff at IPC, I often was left with a long list of faxed questions (you read that right: our boss at the time didn’t like phone calls from those pesky customers) from process engineers mystified by one specification or another. Werner became one of my go-to guys, and always took the time to explain the thinking behind the standards. Who knows how many engineers thought I knew what I was talking about when in fact, I was simply quoting Werner.

Appreciating for years his passion for skiing — Werner would often take advantage of flights from his Florida home to the West Coast by stopping off at one of his favorite mountains — I once mentioned how much I liked the Snowbird resort outside Salt Lake City. Werner laughed, and said he preferred a nearby peak, adding he had a saying, “I ski Alta, and I give you the ‘Bird’ ” a tongue-in-cheek reference to the one-finger salute.

That was Werner. He had his opinions — be it Alloy 42 or lead-free soldering — and stuck to them, insisting on data above politics and the path of least resistance. He was patient and respectful, but he carried that trait to which all journalists aspire: He spoke truth to power.

And, as his son Peter said, he was “reliable” in every sense of the word. It was strange not seeing Werner at IPC Apex last week. It was the first time I can remember him missing an IPC meeting (and I know why he did, although I’m not going to write it here). Instead, he gave a two-day seminar in Israel, then flew to Aqaba, Jordan, to go scuba diving. In his absence, he still received a pair of awards for work on newly released IPC standards.

I will miss a lot of things about Werner: his sense of humor and smile, his tenacity, his mind. But mostly, I will just miss him.



Some Consensus on SAC

Back in November, I posted comments on lead-free availability. In this post, I mentioned that I chaired a session at SMTAI on Alternate 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 Pb-free thermal cycle reliability as a function of silver content and compared the results to SnPb reliability.

Both papers concluded that, as far as 0oC to 100 oC thermal cycle reliability is concerned, in their experiments

SnPb < SAC105 < SAC305 < SAC405

Coyle’s presentation summed it up 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.”

To be clear, it was two papers by two different groups coming to the same conclusion. It would probably be a stretch to say that the conclusions of either group were “almost unique”.

Denny Fritz responded to this blog post with this point: “No one I know will dispute your ranking of SAC better than SnPb solder using the commercial temperature cycle Henshall uses – 0C to 100C. But, harsh environment electronics have to perform to either -40C or -55C, and most use a top end cycling temperature of 125C. IT IS IN THAT WIDE THERMAL CYCLE TESTING THAT SnPb outperforms SAC solders.”

Denny’s point is well- taken. I believe it can be said that SAC alloys have demonstrated acceptable reliability in commercial, non harsh environments (i.e., mobile phones, PCs, consumer electronics, etc.). However, it cannot be said that acceptable reliability for SAC has been established for military (RoHS exempt) and harsh (i.e., automobile engine compartment) environments.

A short time ago, Werner Engelmaier wrote an article on this topic (Global SMT, vol. 11, no. 1, January 2011, pp. 38-40), referring to my post he said: “Of course, ‘Dr. Ron’ selectively picks data agreeing with the point of view he held from the inception of the Pb-ban under RoHS on a plot with an expanded x-axis overemphasizing the differences and supporting a solder joint reliability ranking of SnPb < SAC105 < SAC305 < SAC405.”

Ouch! My motives were not quite so nefarious, I chaired a session and wanted to share the conclusions.

However, Werner makes good points in his article, data exist disagreeing with this reliability ranking and he suggests some good points on how to conduct reliability tests so that comparisons can be made between data sets.

In reading some of his other articles, I was delighted to find that we actually agree on the state of lead-free reliability in thermal cycle testing. Here is a statement of his circa 2008 (Global SMT, vol 8., no. 8, August 2008, pp. 46-48.): “It has been 2 years since the infamous ban of Pb-solders under RoHS. What have we learned? For solder joints, no dramatic differences in reliability are apparent. The data bases for LF-solders have grown, the favored LF-solders might be shifting, and no reliability model exists as of yet. Nevertheless, progress has been made.”

Best Wishes,

Dr. Ron