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Tin Whiskers — Fact Or Fiction?
bLanark writes "Some time ago, most electronics were soldered with old-fashioned lead solder, which has been tried and tested for decades. In 2006, the EU banned lead in solder, and so most manufacturers switched to a lead-free solder. Most made the switch in advance, I guess due to shelf-life of products and ironing out problems working with the new material. Lead is added to solder as it melts at low temperature, but also, it prevents the solder from growing 'whiskers' — crystalline limbs of metal. The effect of whiskers on soldered equipment would include random short-circuits and strange RF-effects. Whiskers can grow fairly quickly and become quite long. Robert Cringley wrote this up this some time ago, but it seems that the world has not been taking notice. I guess cars (probably around 30 processors in a modern car) and almost every appliance would be liable to fail sooner than expected due to tin whiskers. Note that accelerated life-expectancy tests can't simulate the passing of time for whiskers to grow. I've googled, and there is plenty of research into the effects of tin whiskers. I should point out that the Wikipedia page linked to above states that tin whisker problems 'are negligible in modern alloys,' but can we trust Wikipedia? So: was the tin whisker problem overhyped, was it an initial problem that has been solved in the few years since lead-free solder came into use, or is it affecting anyone already?"
Look at it from the manufacturer's point of view. There's a chance that any piece of consumer electronics is now going to wear out and die even faster, causing people to buy replacements more frequently. Sounds like a great deal for the manufacturer with no downside. They don't have to pay to dispose of these things properly. And no, chucking your old electronics in the trash is not the proper way of disposing of them, unless you like cadmium, mercury, hexavalent chromium, and brominated flame retardants seeping into your drinking water.
Make manufacturers bear the ENTIRE cost of properly and safely disposing of their products, and overnight we'd have cleaner, greener, more long-lasting and durable products.
I used to buy into Wikipedia's stated ethos until I realized that any one person can (and all too frequently do) hijack articles to push and protect their point of view and once that happens you can forget about the "Five Pillars" and objectivity.
Yes, because all connections, switches, and transistors are tested by a JTAG boundary scan...
LOL! You've never heard of Analog?
Visual inspection is key to debugging crucial and intermittent errors due to things like badly soldered bypass caps and ground bounce. Put that in your JTAG and smoke it.
It takes *very little* current to short a FET gate, i.e. microamps or less. Indeed, compare the geometry of these whiskers to the tracks etched on silicon. Not every bit of metal exposed on a PCB will carry current large enough to fuse these whiskers before they cause disruption. Furthermore, chip-scale assembly techniques likes BGA will give you plenty of areas with large blobs of solder within convenient whisker distance of each other.
As referenced in another comment, NASA Goddard Space Flight Center does indeed seem pretty concerned:
http://nepp.nasa.gov/WHISKER/
"Probably we don't have any major car manufacturer sued because nobody ever cares to examine cars electronics after accidents. It's so easy to blame the drunk/distract/incompetent driver."
:)
Especially when they ARE drunk/distracted/incompetent.
Automobile systems are very well designed to fail gracefully or just not matter much when they crap out. (That's also why drive-by-wire is a stupid idea.)
The average car is driven by a mechanical illiterate who barely maintains it (washing does not count) and is designed accordingly. I am an experienced mechanic and know whereof I speak.
"This post is an artistic work of fiction and falsehood. Only a fool would take anything posted here as fact."
Yep, if I went to a "legitimate" encyclopedia rather than Wikipedia i'd guess 99% or more of the topics I look up every day wouldn't be there at all.
I don't get all the hate for Wikipedia. So it's not perfect, well neither is the Encyclopedia Britannica, but for me Wikipedia is the single most useful resource on the internet second only to Google, and even that may be a tossup because Google often just links me to a Wikipedia page. I'm there dozens of times every day, whether it be looking up something I saw on TV, an actor's name, a musician's discography, or something I just read about.
It's a shame such a valuable resource takes so much heat. Maybe it has its problems but it's alot more accurate and alot less opinionated than the average webpage you'll find on any given topic, and honestly it doesn't really matter to me that the article on Chevy Chase hasn't been published in a scientific journal for peer review.
On Wikipedia, the truth is what the Admins says is the truth.
And that's different than a commercial information source how?
Commercial sources don't claim to use the so-called wisdom of crowds.
Commercial sources don't say anyone can edit the entries.
There is no "-1 offended" or "-1 you don't agree with me" mod options for a reason.
There really aren't that many consumer electronics items from the 1950s and 1960s in general use, even when they're compatible with "current" standards. The exception are a few items, like those you mention, that were expensive then and are expensive now. There were hundreds - possible thousands - of millions of radios and TVs made during that time, for example. These are 100% electronic items, unlikely to have failed due to mechanical problems (wear and tear), nor incompatible (in practice) with current standards and systems. Where are they now?
There are items made today that will still be in use in 40 years time, but the number is small, and as with the previous example, they'll be the obscure, highly priced, built-by-craftsmen objects. The "decline in quality" meme is a myth. If it's built in a factory, for the mass market, it isn't - and never has been - in the manufacturer's best interests to make it last for more than a decade. Exceptions exist - but they'll always exist. And, to be honest, there's a remarkable amount of stuff hitting landfills these days not because it fails to function as designed, but because it's obsolete. I suspect the number of 8088-based PCs that could still be working if their owners hadn't put them in the trash would probably number in the tens of millions. And that was hardly an industry where quality was considered a priority.
You are not alone. This is not normal. None of this is normal.