Tin Whiskers, Short Circuiting Our Lives.

[Michael Ou]

This post is not an attempt to spread FUD, but to educate and inform us regarding the long term affects of the reliability of all lead-free electronics. This is NOT a RED problem, but a problem for all electronics that may contain lead-free solder (yes that would include Arri, Sony, Panavision, Blackmagic, Canon, etc.). This is pretty much also limited to cars, aviation, high-tech/nuclear weapons, boats, the computer industry, telecom, aerospace, medical devices, toys. . . or any device that uses solder, circuit boards and tin plating.

With the global trend to rightfully protect ourselves from the dangers of Lead poisoning and contamination. There has been revealed an unfortunate phenomenon with the adoption of lead-free solders and electronic components meeting the EU's RoHS certification: Tin Whiskers.

(Excerpts taken from a paper submitted to NASA 8/2011)

What are tin whiskers?

Tin whiskers are spontaneous hair-like growths from surfaces that use Pb-free tin (Sn) as a final finish
–Electrically conductive
–May grow in hours, days, weeks, or years
–Pb-free tin-plated electronic & mechanical parts can grow whiskers

Tin Whisker Background
•Tin whiskers were first reported by Bell Labs around 1947
•Growth inception and rate varies widely
–Can start growing after years of dormancy or in a few hours
–Whiskers can start growing, stop, and then resume growing
•Whisker shapes and forms vary considerably
•Lengths range from few microns to over 20 millimeters
–23 millimeters is the current record holder
•Up to 200 whiskers per square millimeter have been observed
•Whiskers can grow through thin conformal coatings


The full paper can be found here (tin whiskers begin at page 41):
http://nepp.nasa.gov/whisker/reference/tech_papers/2011-kostic-pb-free.pdf

Especially interesting is the cause of the 2005 Toyota Camry sudden acceleration issue to be attributed to tin whiskers (p 57)

It's a good thing that this information is being widely disseminated as the EU's well-intentioned policy has not yet been adopted globally. It's certainly not too late to address this concern.

 

[Tim Whitcomb]

wow thats fascinating if not disturbing. thanks for sharing!

 

[Michael Ou]

To date, no real solutions have been found, besides adding a minimum 3% lead to tin solder. On the darker side, this is a potential short term/high cost (to us) windfall for manufacturers as all our RoHS electronics become disposable items after their warranty periods. Companies stand to make fortunes over this phenomenon, I wonder how motivated they really are to address this problem?

 

[Nick Eason]

The problem is that as long as RoHS is in effect in Europe, its in effect everywhere since no company wants to bother with 2 product lines for different regions if they can help it.

While this is a happy accident for the consumer electronics industry, its a serious safety hazard in critical systems like life-support and cars. These companies stand to loose millions in lawsuits. But solutions to chemical problems like this do not come easily. Like you posted, the phenomenon has been known for decades and there is no solution as of yet.

To date, no real solutions have been found, besides adding a minimum 3% lead to tin solder. On the darker side, this is a potential short term/high cost (to us) windfall for manufacturers as all our RoHS electronics become disposable items after their warranty periods. Companies stand to make fortunes over this phenomenon, I wonder how motivated they really are to address this problem?