RoHS, Six Years After

Folks,

I was at IPC Apex Expo the other week.  San Diego is a great venue for the show, but I always forget how cold it can be (55°-65°F) this time of year.

While at the show, I was interviewed on lead-free reliability and its cost for consumer electronics. These are topics I think about often, so let’s discuss them a bit. First, let’s consider reliability.  RoHS was enacted on July 1, 2006, more than 6 ½ years ago. Each year more than $1 trillion worth of electronics are made, therefore, in this period of time, something over $3 trillion worth of consumer electronics have been manufactured. There have been no “the sky is falling”-type of reliability issues in this time. How can I say this? Well, my office at the Thayer School of Engineering at Dartmouth is across the hall from the IT (information Technology) Dept. They purchase all the millions of dollars worth of PCs, printers, displays etc. that Thayer uses. Several years ago (say early 2011) I stopped by when most of the department was in and cheerfully asked if the reliability of the equipment they purchase has gone down since lead-free assembly was enacted. They asked me in unison, “What’s lead-free assembly.” After I explained what lead-free assembly was, they confirmed that they have noticed no changes in reliability. Since RoHS, my family has purchase about 100+ electronic devices, a few have had reliability problems, about as many as in the past. Most were attributed to hard drive fails. Of the scores of friends and colleagues I have, no one has ever commented that they have noticed an increase in electronics fails. So, my conclusion is that consumer product reliability is not “practically” worse if my family and  these many  other folks haven’t noticed it.

I have made an informal study of reliability data of lead-free vis-a-vis tin-lead solders published in papers. A statement from Rockwell Collins’ JCAA/JGF-PP No Lead solder Project: -55C-125C Thermal Cycle Testing Final Report  sums up my overview conclusion nicely: “Test vehicles assembled with lead-free materials (notably tin-silver-copper) exhibited lower reliability under some test conditions.”  Naysayers might be quick to suggest that this statement says that lead-free is no good. However, the statement could be reworded to say: “In considerably more than half of the test conditions, test vehicles assembled with lead-free materials had higher reliability.” Counting the comparisons in the Rockwell-Collins paper shows lead-free better in 51 cases, tin-lead better in 31 cases, and one draw. However, it is disturbing that a small percentage of lead-free assembled test vehicles had much much worse reliability than tin-lead test vehicles. This later information makes me believe that lead-free is not yet ready for mission-critical, high-reliability, long-life products. These small numbers of much poorer reliability assemblies must be understood and corrected before lead-free is ready for mission-critical prime time. The much shorter lifecycle of today’s consumer electronics may also mask this concern.

What about cost? I don’t at all want to minimize the expense that many went through to go lead-free and RoHS compliant. In about 2007, one of our colleagues estimated that it cost the electronics industry $20 billion to become RoHS compliant. I think this number is low, but, from a consumer’s perspective, there has been no cost hardship. The price of a PC continued to go down during and after RoHS implementation, as shown in the figure below. While performing my non-scientific survey of co-workers, family, and friends on reliability, I also asked about cost. All agreed, electronics are cheaper than ever.

 

Challenges still exist, even in consumer electronics with the Head-in-Pillow, Graping, non wet opens, and other defects.  However, we can all purchase lead-free, RoHS compliant products at a reasonable cost and reliability.

 

Cheers,

Dr. Ron

The source for the image is :http://thomaslah.wordpress.com/2010/02/03/apple-and-intel-defying-gravity/

 

Best Wishes,

Dr. Ron

About Dr. Ron

Materials expert Dr. Ron Lasky is a professor of engineering and senior lecturer at Dartmouth, and senior technologist at Indium Corp. He has a Ph.D. in materials science from Cornell University, and is a prolific author and lecturer, having published more than 40 papers. He received the SMTA Founders Award in 2003.
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