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Zinc Whiskers Cripple Colorado's Computers
Mr. Christmas Lights writes "While zinc whiskers, small metallic fibers which grow on surfaces that have been electroplated with zinc, aren't a problem for Christmas lights, they can cause serious problems for computers. The Denver Post reports how they caused computer outages for the last three weeks in the Colorado secretary of state's office. This basically halted business and elections document filings. Zinc whiskers are becoming more of a problem as computers electronics get smaller. NASA has a good reference site which includes a interesting PDF summary paper complete with pictures. /.'ers with computer rooms might want to check this out."
Shocking! /sorry, couldn't resist.
Etiquette is etiquette. He kills his mother but he can't wear grey trousers.
I read the article, and I call bullshit. And FUD.
There is nothing special or unique about the computers in that particular office.
It's just a completely normal office. They are blaming their computer problems on some esoteric, invented problem rather than what's really causing them.
The person they interviewed, from Data Clean, specializes in building "clean rooms." Never in the history of computers have we needed a clean room to operate a computer. Obviously Rich Hill just wants some extra contract work.
...with a magnet!
I'm probably at the karma cap. Mod up a funny troll instead, it lightens the mood
Kind of makes you rethink the reliability of data centers, being that floor panels are used almost exclusively there...
Zinccccccc Zinnnccccc! Oh my god what have I done!
I don't need no instructions to know how to rock!!!!
I am wondering if they will have some sort of sheilding system for this in the future, if it becomes more of a problem. That could be as simple as a small layer of some nonconductive resin on the surface of the circuits. But will it ever be economically feasible?
I suppose in the mean time we'll have to do our own safeguarding if we are in a risky area.
The Cheese Stands Alone.
I guess we have to shave all zinc cats before we let them into the building.
Never attribute to stupidity what can be construed as a monopoly preservation tactic.
The metal frames for the raised floor are where the zinc whiskers are coming from. They get sucked into the power supplies and short them out.
"Do the Right Thing. It will gratify some people and astound the rest." - Mark Twain
"Do the Right Thing. It will gratify some people and astound the rest." - Mark Twain
Anybody ever see, much less be affected by, "zinc whiskers"? In the one or two times I've seen anything resembling this, I always thought it was metal shavings from the assembly process. That, or clever dust :-)
We are in the final streach for replacing the entire datacenter floor where I work because of zinc Whiskers. We had the underfloor area cleaned for the new A/C that blows from the floor up. We promptly lost 11 power supplies and the total count is up over 20 now. We did verify the presents of zinc whiskers in the dead powersupplies thanks to the onsite electron microscope.
Thankfully the high temperature never got above 85 degrees so the old A/C was able to keep up.
... amazinc.
Here's a yummy little google cache for y'all.
(-(friend^2))^(1/2)
Incoming mod-bombing for having a different viewpoint, 2 o'clock! Heads up!
Maybe they should invest in some cleaners...
Yup.
And the metal that the whiskers come from, have been used for computer room floor tiles, racks, and even (shudder) PSU cases.
Now that's scarey.
Robert Anton Wilson
I thought almost all quality electronic devices have a conformal coating (non-conducting polymer) applied to PCBs? Colorado must be buying el-cheapo crap. Remember, you get what you pay for.
"I'd rather be a lightning rod than a seismometer." -Ken Kesey
And are a problem with the new lead free processes.. especially as lead spacing decreases, and the euro lead-free requirement kicks in.
Agere wrote a good article in Analog Zone, available at http://www.analogzone.com/grnt0216.pdf. It has a good micrograph showing the problem.
"'Tis great confidence in a friend to tell him your faults, greater to tell him his." --Poor Richard's Almanac
I work in a large midwest hospital, and we've got a constant issue with Zinc whiskers in our network jacks in operating rooms. Supposedly the origin is the cleaning solutions that they use for the floor.
We have 3 rooms where I work that house our servers. We are migrating some stuff over to an HP-UX system running oracle. When we had some HP representatives come over to our area to check out the place we intended to house the HP servers, they insisted that zinc whiskers could potentially be very damaging and that we make sure our rooms were clean and free of zinc whiskers (not that our rooms were particularly dirty). I always wondered how legitimate their claims were.
Couldn't manufacturers spray some sort of nonconductive film onto new boards?
With regard to the NASA reference, could you please go into more detail? I though growing crystals were slow to enlarge and fragile. I'm not doubting the veracity, I just don't understand how zinc crystals could grow *through* an inch of epoxy.
Zinc Whiskers? Hey, they stole my username!
Ok, no they didn't.
someone (I can't recall who) offered a prize to the site that could generate the highest google pagerank for the nonsense phrase "Nigritude Ultramarine". I'm sure if you google you can find some more information.
#931654: "Sorry, our computers seem to be growing metallic whiskers. What did you say your username was? bwahahahahaha"
bash: rtfm: command not found
My A-100's chorus/vibrato likes to go on summer vacation when it gets humid in the house, but works fine during the winter. Just thought I'd throw that in - I think the stuff is zinc-plated...
HAHAHHAHA a comment about the site being slashdoted!!!! How original and funny. MOD PARENT UP!!!111
See parent poster for details of the immaculate first post.
Did I ever mention that my mother looks like the cunt of a shaven yak?
With all the RoHS crap going on (the "lead free" european requirements), you'll be seeing a lot more failures do to tin wiskers. It's already looking like it will affect the life of most future electronic products.
First Computer Viruses,DoS, and now this ! Can't we see that humans and technology don't go along very well?? let's all go back to the dark ages *ZINC* .... Oh no I was just kidding!
What is best in life? To crush your enemies, to see them driven before you and to hear the lamentations of their women.
" I guess we have to shave all zinc cats before we let them into the building."
That's not a cat you're shaving.
...small compact computer designs get these whiskers easier. I don't doubt it happens, but where are all the millions of laptops shorted out then, or the mini itx machines,game machines, etc?
Is there something else here causing whiskers to grow some places and not in others, even though both have zinc?
and a narative
Access Floors
Today's power supplies suck. Zinc whiskers, my ass. I call BullShit.
Wohoo first post ever on slashdot!
Anyway, I work at an IBM data center with many computers and sensitive equipment around. We have zinc ducts here(well they look like zinc so I assume they are), and in the 15+ years this place has been running no problems have become of it as far as I know. That is no problem that can be traced to it. I suppose it is possible some problem that was blamed on something else could of been caused by this, but I've never heard of it.
Just some info.
"On-site electron microscope"...to "verify" the presence...
/. has gotten so lame.
Ummm... yeah.
JFC!
"Ironically, there are wood based floors used in data ceneters with steel reinforcing on the back of the tiles that are zinc-electroplated (thus being essentially undisturbed for years). So if a fairly old data center, that happens to have the right (wrong?) type of flooring, undergoes an upgrade or reorganization... well that might do it."
Reminds me of Asbestos. Silently waiting, until disturbed.
technology rears its cold head, and the zinc-whiskered men and women of the airplane and car rise up against their fathers...
I know I speak against my own name, here. But:
Living by the sea, especially with the high humidity that comes with it...and the salt...can give your more than just a few zinc whiskers on the PC board.
Salt oxidation--depending on how long the windows are open--can really eat a PC in two years or less; never mind the quality of the MB.
Sea salt is hydrophilic. If it accumulates on something, episodes of high humidity will attract moisture from the air, and add the basis for typical corrosive effects. I have had containers with dry sea salt, which have pulled moisture out of the air on their own.
(Most acids need water...so does salt to release it's own ions, which can have a corrsive effect similar to an acid on metallic equipment...usually involving the non-metal in the salt. Sea salt has lots of chlorine, a very strong oxidizing agent.)
So the days of calling program errors 'bugs' is finally over, huh? Now we need to call them 'whiskers'! Time to update BugZilla to WhiskerZilla I guess..
If these things are so small as to require an electron microscope to see, why arn't they simply vaporized/melted as soon as they find themselves shoved between two (relativly) massive wires?
You'd think that a microscopic piece of zinc would go before a macroscopic fuse/chunk of copper/etc. And since it's alot of single pieces blown around, it's not like several million are all going to do it at exactly the same time.
I've melted zinc, and it's pretty snappy, (Pennies after 1982 are mostly Zinc. When you melt them, you get a cool copper-skin effect going on.), but with the same torch ($15 propane torch) I was unable to even visibly affect the copper.
What this has to do with zinc whiskers, I fail to see.
in my life God comes first.... but Linux is pretty high after that
Francis Smit
We had to replace all the raised floor panels in one of our old data centers because of zinc whiskers. It took us a while to figure out what was going on.
If you had taken time to check into it, you could have avoided looking foolish.
I'm not completely sure, but isn't this one of the purposes of silk screening anyway? Which happens to be done on every single motherboard I've ever seen....
I'm not sure about this, though, I could be wrong.
-ReK
md5sum -c reality.md5
reality: FAILED
md5sum: WARNING: 1 of 1 computed checksum did NOT match
I've had a similar problem with zinc wiskers. I live in southwest Missouri, the zinc capital of the world, and every morning I wake up with a five o'clock shadow of old Atomic Number 30. I find that the Mach3Turbo from Gillette is the best solution to the problem. Word of advice- never use an electric razor, especially if you've recently washed you're face with water. Trust me, it's a volatile mixture.
...green dots are an audio solution. This smacks of freakish pseudoscience masquerading as real problems. Kind of like the gold plated power cords for stereos that cost audiophiles $180 each. The supposed reason that they improve sound is that gold has less resistance and therefore your amp will perform better if the electricity gets to it more readily. That's bullshit just like the zinc whisker issue.
Un-news
Our whole terminology is going to change. What was debugging is going to be called shaving, and instead of running DDT I'll be running Gilette to trace through and eliminate whiskers from my code. I guess it's finally time to learn FORTRAN++.
Tag lost or not installed.
Which effectively means that it's a component of dust... so if you have dust buildup in your room, you're likely to find this among other problems forming.
The only thing I can think of is the MST3k short where a man wishes there were no springs, and a satanic spring elf named "Springy" laughs manically as everything with springs stops working.
Not a Twitter sockpuppet... but I wish I was.
I'd be a lot more inclined to believe the "whiskers" are coming from movement of the tiles when people walk across them(they do shift, as does the frame slightly) and not some "growing whiskers" BS.
Furthermore, the problem is easily solved via any/combination of these:
Furthermore, if the little buggers are metallic, why don't you just install a few small but powerful magnets in various ducts? A metal grate made up with a set of magnetic rods would probably work like a swell charm, and only require periodic cleaning...
Please help metamoderate.
I had a close call with this problem in a 1960's era Kodak 16mm projector I was restoring, 2 months ago. It had a zinc-plated shield over the electronics, and the shield itself was absolutely thick with zinc whiskers.
The layer of whiskers must have been around 3mm to 5mm deep. They were a soft grey, but you could see them sparkling in the light.
After I removed this component for cleaning, I could immediately see thousands of the little needles floating around in the air, sparkling in the sunlight, just itching to be inhaled. Asbestosis, anyone?
D'Oh!
Well, I have the symptoms. Losing lots of power supplies, some systems are really flakey. We have powerful fans blowing air through the floor. Looks like we have the susceptible tiles. I pulled a couple, set them on thier side, turned out the lights, and looked them over with a flashlight. There is something there, at first glance it looks fuzzy, like a coating of dust, but I doubt that dust collects on the underside of the tiles. Anyways, as I looked across it, it does look like many tiny hairs growing out of the bottom tile surface, like a really short stubble. So am I just sounding like a hypocondriac or what?
I figure with the way things work here, they say sure, could be a problem, no budget to fix it, but you better get all those systems back on-line again, and no, you can't have any spare parts like replacement powersupplies.
I work tech support. I can't wait to start using this as an explanation of all sorts of things:
Customer: When I go on mah Innernet, I get this error 'bout id not bein' displayed.
Me: Sir, it looks like you've fallen victom to Zink Wiskers. No sir, you don't need to get rid of your cats.
Hi! I make Firefox Plug-ins. Check 'em out @ https://addons.mozilla.org/en-US/firefox/addon/youtube-mp3-podcaster/
Well done AC.
If you want, I'll send you a copy on Wednesday when I get back to work.
No, I'm not worried about zapping floppies. Your ideas are, for the most part very good ones, but zinc is paramagnetic, if I recall right, and is not attracted to the magnets. Same for tinfoil, BTW. The magnets would be effective in catching iron filings and related ferromagnetic particles, though, but that didn't seem to be the reported problem in this case.
Your friction hypothesis has merit, too, but growth of whiskers, more scientifically known as dendrites is actually quite common, especially where electric fields exist between conductors. I ran into that in a flexible touch keyboard we had designed using a silver alloy that was screened on as the conductors. Durn things would develop shorts after a while in the field, literally since it was on agricultural equipment. You couldn't see the shorts, but examination under a microscope revealed those nasty little whiskers. A metalurgist was consulted and provided a different alloy that solved the problem.
"Do the Right Thing. It will gratify some people and astound the rest." - Mark Twain
"Do the Right Thing. It will gratify some people and astound the rest." - Mark Twain
It's also worth noting that, at the finishing.com link I gave above, you'll find Cisco and well-known companies have known about this problem since at least 1996. Or perhaps finishing.com is involved in the conspiracy, or Cisco power engineers are idiots.
1. I first like to thank simoniker for adding the "small metallic fibers which grow on surfces that have been electroplated with zinc" to the article - made it more understandable/readable.
2. The NASA URL is one-level deep (a mistake on my part) - here is the top-level.
3. Related to #2, I would STRONGLY recommend /.'ers actually READ what that says. The Denver Post article was written by a reporter - would you expect that to be technically accurate/broad/etc? Again, take a look at the NASA site which DOES present a compelling case that this is a REAL issue and not FUD. The original study with the medical equipment makes for facinating reading.
4. Some Anonymous Coward seems to have a problem with my nickname. Did you actually click on the "Mr. Christmas Lights" and see what is there - tell me that isn't appropriate (it's been used before BTW).
5. The same AC made a smart-ass comment about the Nigritude Ultramarine SEO contest - while I'm aware of that contest (#4 above is a hint for 'ya!), I'm currently ranking #199 for the keyphrase with less than a week to do, so I'm not a contendor ... although I do rank #1 for the phrase Nigritude Ultramarine Hulk! ;-) ... and I actually did submit a wrapup article a few days ago about this, but it got rejected - good news is the contest is over July 7th, so all those N-U links will go away - they are a bit annoying.
6. I haven't seen anyone comment on a business (verus technical) aspect of the Denver Post article (but this is /.) where some state mucky-muck basically says this is a reason to bring all state websites under one authority and talks about $7.5 million in funding. One wonders if some empire building going on and/or play for more money!
7. There have been several Denver Post articles about the failure of these computer systems. I didn't mention that fact in my submission because I thought it would be too lengthy, but apparently the inability to electronically check/file business/elections stuff has been a real big deal - good example of our dependancy on computers.
'Nuff random late night rambling!
Hulk SMASH Celiac Disease
They'll do anything to keep Nader off the ballot in a swing state. :-)
dinner: it's what's for beer
There is a value to gold connectors, they don't tarnish, ergo, the connection doesn't degrade.
Is it worth the extra money? Not usually, but there is a benefit.
However, I do love when I hear people talk about improved 'sound quality'.
I always ask "So, the wires are gold as well?"
Usually the light downs.
I wil admit I have been out of the audio[hile loop for about 20 years. It seemed the widespread use popularity of CD's brought with it a large number of idiots who thought they where 'ausiophiles'.
Us a market around the edge of a CD to get better sound quality, indeed. bah
The Kruger Dunning explains most post on
I live within a mile of the ocean, and we have a lot of fixtures in our house which must be made of zinc, because they grow these whiskers just like were described. We have a chandelier in particular which looks like it's brass, but it's always covered with fuzz. Then I have a chin-up bar in a doorway and the same thing happens to it.
I wonder if it has to do with some kind of electrochemical reaction, where maybe there have to be different unlike metals with varying electronegativity, and enough humidity to get a low grade current flowing between them. I never saw this problem, when I lived elsewhere. But if my computers had zinc in them I'm sure it would grow whiskers just like the rest of my house.
Empty the computer room of all computers, and circulate the air through a filter that has somewhat dilute hydrochloric acid (Or whatever cheap stong acid) absorbed into it. The zinc will react to form ZnCl2 which will dissolve in the water. Shouldn't be to costly. Have one IT staffer and some grunts do it.
I hate grammar Nazi's.
there isn't even a link for zin whisker in wikipedia, but there is silver whisker and don't forget goatse is in wikipedia
steal this sig
The gold is to prevent corrosion leading to a degraded connection over time. I believe it also eliminates galvaniic corrosion issues. The difference in anoodic index between copper and iron is like .70 which pretty much guarantees corrosion even in a dry environment.
There is a value to gold connectors, they don't tarnish, ergo, the connection doesn't degrade.
Is it worth the extra money? Not usually, but there is a benefit.
Tin and lead tarnish yet it's still very common place. Silver also tarnishes yet is, or at least was common place on larger ships. Aluminium tarnishes practicly the moment you expose it to air. The wisdom to what you say is the fact that a copper tarnish aka copper oxide is an insolator.
I've been upgrading to gold connectors simply because i've been finding them for $3.99 per RCA pair. I don't claim they are the apex of audio cables, but they are decent quality and better then your mega-mart varity.
There is no sanctuary. There is no sanctuary. SHUT UP! There is no shut up. There is no shut up.
I really hate this shit. When the opportunity arrives, some fuckstick gets the brilliant idea to go create a unique username and post something relevant to the story to get modded Funny and then the account is never heard from again. First of all, it is usually only mildly funny. In this particular case, it is not funny at all because it is so completely fucking obvious that you created that account 10 seconds ago. Secondly, it is wasteful. It takes up an entry in the Slashdot database and it takes up a username. It is entirely possible that a legitimate user would want to register under that name at some time in the future. Now they will be unable to do so. Thirdly, and lastly, FUCK YOU! YOU ARE A MOTHERFUCKING COCKSUCKING SHITFACED FAGGOT! I hope you get taken captive by Unity and Jihad.
The real reason for gold plating has more to do with oxidation than the resistance of the different metals. Dending on where you live, those connections can develop problems fairly quickly. I also had someone point out that they paid a LOT of money for their equipment and don't want any dissimlar metal issues. While I'm not sure about the odds of that being an issue, who am I to quibble with him over a 100 dollar cable to hook up 3000 dollar rack equipment?
_damnit_
It's my job to freeze you. -- Logan's Run
problem happens in copper wiring small copper "whiskers" grow right through the insulation. if two wire are close when this happens they can short out and cause fires. usually only happens in really old wiring
Has the risk been put to any scientific testing? Or just a theory to blame crap on? I'm not leaning either way. I find this fascinating but I am just wondering if it has stood the test of the scientific method.
If something exists that does not need a creator (god) then why must the cosmos need one?
I'm curious as to what preparation process you used to preserve the fragile 3-D structure of the Zn whiskers. How did you differentiate the between the Zn whiskers from something like fibreglas insulation and other atmospheric floaties in your sample collection, or did you just plate everything?
Also, what kind of controls did you use?
(Curious because this may have an application outside of old floortiles.)
There are 1.1... kinds of people.
hmm... Nothing change in my trouble shooting routine...
:)
#1 Beat the crap outta it.
#2 Try #1 again, otherwise engage brain.
Is it just me, or does this "problem" have applications. If these fibers conduct electricity (as they must in order to cause shorts) and they are "grown," it seems to me, some clever person out there might figure out a way to grow circuits out of them. The /. crowd has GOT to have someone that sees this too.
Come back zinc! Come back!
Zinc? Zinc? It was just a dream, zut my good computer still doesn't work. Damn you ZINC!!!
he said 'electron microscope' as in a microscope that runs on electrons. As all microscopes do. duh!!!
But then I thought to myself "too scary to be true" (especially the claims of asbestos-like hazard, in addition to the short inducing), and so I scrolled back to the cover page to doublecheck the date...
Hi, It just so happens that I work with this guy and he his correct in his statement. In fact my mom is the electron microscopist on site. Please note this is a VERY OLD electron microsope. around 8 - 10 years old. It doesn't have the ability to look at the lattice structure of a molecule because it simply isn't powerful enough. In our case the zinc whiskers where in the hundreds of microns in size. There is an attachment to the machine that can give you a breakdown of metals in the sample you are analyzing. In our case it was very obviously zinc. We have had problems with our new Sun equipment popping power supplies for several months nows (V480, 420R, etc.) although none of the Ultra 2's have had a problem at this point. We thought it was heat and power (thus the new AC unit for cooling) and the power checked out ok. The sun rep said we are the only company we service that was having supplies pop (in fact the data center across the hall wasn't having any issues but they have different tiles than us) when we had the cleaning crew in to clean under the tiles (prep for the under floor AC unit...note that we are using ceiling air now) In the span of 3 hours during the cleaning we lost 13 supplies all on new sun equipment. Once they stopped running vacs and pulling tiles it dropped off. Sun confirmed (with a sample of five dead supplies) that they were all caused by a short. Our tiles were wood core with hot dip galvanizing that had been recycled from an old computer room. These tiles had 20 years plus of use.
Hi, Another note about how the electron microscope came into play. My mom took sticky sample pads and stuck them onto the bottoms of the floor tiles and then put the sample pad in the scope. In addition, we took the same sample pads and ran them over the input fan shrouds of the dead supplies. In the case of the floor tile samples the whole thing is pretty much just zinc whiskers. In the power supply samples it is a mix of dust and zinc.
"It's not my code, it's the zinc whiskers"
As I recall, old computer used to suffer from mice chewing on the wires and they used to keep a cat to keep the programs running smoothly. Then it was bugs and I am not sure if spiders helped or added to the problem.
I, for one, welcome our new zinc-eating nanobots.
> There is a value to gold connectors, they don't tarnish, ergo, the connection doesn't degrade. Is it worth the extra money? Not usually, but there is a benefit.
Take a look at a PCI edge connector. Most of the better ones are gold-plated, but some low-end cards are tin-plated.
Is there an advantage to the gold-plating? Yes, it doesn't tarnish as fast, so the conductivity remains good even with age.
Is it worth the extra money? The plating is a few microns thick, so it only costs a few pennies more than tin. But the $100 graphics accelerator on which it is found will work reliably for 10 years instead of 6 months. So I'd say, yes, it's worth the additional 2 pennies to go with gold plating.
No, this is real. Here's why: a tarnished connector can become a non-linear junction. Tarnish such as a thin film of a sulfide, in contact with a 'pure' metal, can be a rectifier. If you put one on a curve tracer, you could actually see this. So there really is merit in a gold, i.e., non-corrodable, connector.
it may delay whisker production, but it won't prevent it.
Well, if those guys are involved, you just know it's a hoax.
Zinc is not attracted by magnets. The only ferromagnetic materials are iron, nickel and cobald.
Magnets will have no effect whatsoever.
What person will donate an airborne act of love?
For a while I worked with heavily galvanized radio tower parts. I noticed that I would occasionally get splinters from these parts or that the surfaces of galvanized steel could sometimes feel crunchy the first time it was touched. I knew that I could get splinters from freshly cut sheet metal but I couldn't figure out how galvanized steel could have metal splinters, now I know.
Move Zinc
(could not help myself, sorry)
Sweet. Lusers were getting wise to our PEBCAK and solar radiation excuses anyways.
Thermite is the stuff dreams are made of.
I don't read or respond to AC posts
As cut/pasted from my browser
HTTP 403.9 - Access Forbidden: Too many users are connected
Internet Information Services
GO NASA, GO!!!!!!!!!!!!!!! *WWoooooooooo!!!*
Life is like a box of chocolates, you never know when your gonna get food poisoning.
The EXACT mechanism that creates the metal (tin, zinc, etc.) whisker shaped crystals is unknown but LOTS is known:
What are the Commonly Reported Characteristics of Tin Whiskers?
The vast disparity in the observations reported by different experimenters is evidence of the complications associated with understanding and controlling tin whiskers. The following list is intended to provide a very basic overview of some of the observed characteristics of tin whiskers.
1.
Shapes: Whiskers may be straight, kinked, hooked or forked. Their outer surfaces are often grooved. Some growths may form as nodules or pyramidal structures.
2.
Incubation (Dormancy) Period: Experimenters report the incubation period may range from days to years. This attribute of whisker growth is particularly concerning because meaningful experiments to determine the propensity for a particular process to form whiskers may need to span very long periods of time.
3.
Growth Rate: Growth rates from 0.03 to 0.9 mm/yr have been reported. Growth is highly variable and is likely to be determined by a complex relationship of factors including plating chemistry, plating thickness, substrate materials, grain structure and environmental storage conditions.
4.
Whisker Length: Whiskers as long as a few millimeters are not uncommon with some experimenters observing whiskers as long as10 mm (400 mils) in length.
5.
Whisker Diameter: Typical diameters are a few microns with some reports as large as 10 um
6.
Environmental Factors: There is a great deal of contradictory information regarding environmental factors that might affect whisker formation. Several organizations are attempting to devise accelerated test methods to determine a particular plating process's propensity to form tin whiskers. However, to date, there are no accepted test methods for evaluating whisker propensity. Indeed, much of the experimental data compiled to date has produced somewhat contradictory findings regarding which factors accelerate (or retard) whisker growth.
Temperature: Some experimenters report that ambient temperatures of approximately 50C are optimal for whisker formation, while others observe that room temperatures (22C to 25C) grow whiskers faster. Reportedly, whisker growth ceases at temperatures above 150C
Pressure: Whiskers will grow in vacuum as well as earth based atmospheric pressure.
Moisture: Some observe that whiskers form more readily in high humidity (85% RH) whereas others report moisture is not a contributing factor
Thermal Cycling: Some experimenters report that thermal cycling increases the growth rate of whiskers, but others report no effect due to thermal cycling.
Electric Field: Whiskers grow spontaneously without requiring an applied electric field to encourage their growth. Some recent observations of tin whisker induced field problems in the commercial sector seem to suggest that an electric field could stimulate whisker growth, but more analysis is required to confirm these effects (if any). GSFC has demonstrated that whiskers can bend due to the forces of electrostatic attraction thus increasing the likelihood of tin whisker shorts (ref. to GSFC experiment #4).
7.
Whisker Prone Processes: There is tremendous debate in the industry regarding which plating processes are prone to whisker formation. Most of the literature agrees that "pure tin" electroplated surfaces (especially those that employ brighteners in the plating process) are the most susceptible to whisker formation. There are also reports that tin-lead plating can also grow whiskers; however, such whiskers are generally reported to be less than 50um long.
In their Best Practices Guide for the E10000 (written back in 2000) metions zink whiskers in 2.3.0.
Weird... So if Zinc Whiskers can cause system failures, what does breathing in 1mm/2mm strands of zinc do your your lungs? Silver Lung Disease? SysOps Disease? Breathing zinc can't be much better for you than breathing asbestos.
Yikes, I'd be more worried about getting these things in my lungs...that can't be healthy.
What was debugging is going to be called shaving
You deserve some points for this, but as I've already posted in this thread, I'll have to give you an honorary +1 Funny. It's like an honorary degree, but not as good.
For great justice
Take off every zinc!
Sorry, but someone had to say it...
Let's see - terrifically important election coming up, largest voter-registration drive in history, Republican governor, sudden 'mysteriously undiagnosible computer problem'.
Yeah right. Why don't the Colorado Republicans just start shooting or arresting the Democrats - worked in the 1800's. I swear, these people are shamelessly stupid and power-mad.
Bottom-line fact: Dubya gets reelected, there's going to be riots and a LOT of big businesses are going get 'severely damaged'. Time for King George and his painfully-ignorant cronies to GET THE FUCK OUT.
Yeah right sure.
u si nessNews&storyID=5576217
e 32 67.htm
http://www.reuters.com/newsArticle.jhtml?type=b
And while we're on the subject of King George II,
why aren't we hearing about this:
http://www.informationclearinghouse.info/articl
Bush is a vicious bastard and is going to be voted OUT, regardless of what his idiot cronies try.
Please, please, get some fiber - maybe a nice hot enema too.
Bullshit. You have NO idea what you are talking about.
Modern switching supplies use IC controllers, many of which are going to very fine pitch packages. A very small whisker can short out the signals in the control circuit, where the currents are miniscule.
Sure, a whisker across the output will be vaporized. A whisker across a high impedance portion of the voltage regulation feedback loop won't be vaporized, and it could cause the output voltage to spike, causing all sorts of other failures.
BTW, I've designed supplies that are run by CPU's. You admit that zinc whiskers could cause problems with a data bus. Why do you refuse to consider that power supplies also have sensitive signals?
So.. you stuck the pads on the floor and zinc, then you stuck the same pads on the fans and found dust and zinc.
Maybe just maybe the zinc was from the floor, not the fans?
And before anyone points out that they're the same thing, they're not. Galvanizing involves dipping steel into molten zinc. Despite the name, it has nothing to do with galvanic action, electroplating or Mr Galvani. Galvanized panels don't suffer from zinc whiskers, anyway.
When I am king, you will be first against the wall.
I bet they didn't think of that. da-huuh huh huh.
Nice!
"Well, with zinc whiskers, you won't have that computer."
*ding!*
"Or that power supply."
*ding!*
"Or your husband's pacemaker."
*ding!*
"Or your artificial limb."
*ding!*
1. Make rework much harder. The plastic coating has to be carefully scraped away to fix a soldering error. Even with cheap Chinese labor it would be expensive.
2. Affect impedances. Commodity motherboards already have low (let's be honest: negative) timing margin. Random-thickness plastic coating over those long squiggly traces would make a bad situation worse. OTOH, it might not be so bad for the self-timed serial links that are becoming popular.
3. Have a higher failure rate. The spray will sometimes get onto connector and jumper terminals, and that sort of flakiness is way expensive.
First in years gone by there was rumours that seagate had a fluid filled drive, this was to protect against movement of the drive heads to allow more platters in the smaller frame. Second using a non-conductive liquid (such fluids exist 3M i think makes it, but right now it's expensive), you could have a completely sealed system, with a heat exchanger, outside of the case. This benefits the computer, in a few ways, no dust (which most people have a dust elephants in their computers); better performance(this fluid actually improves electrical flows with small gaps); quieter system, if needed you could move a fan to another area, or altenatively larger water reserves as well; lastly with a sealed case, you have better security of the system, which is more important in a work environment.
It's Fluorinert Here's an interesting thing for you overclockers, this guy got out of the Celeron 366 he got it to over 600 http://www.octools.com/index.cgi?caller=articles/s ubmersion/submersion.html
http://www.octools.com/index.cgi?caller=articles/s ubmersion2/submersion2.html
Zinc does grow whiskers. Ask anyone who's worked on a GE MASTR II radio (certain vintages) where the helical coils in the receiver front-end get shorted out over time by "dendrites" as they've been nicknamed in the radio world.
Walk over to the radio, give it a few solid whacks with your fist and the receiver gets a microvolt worth of additional sensitivity!
Interesting that NASA says they've seen these grow right back through their coatings they put on top of it. The "fix" for these radios is usually to remove the receiver casting and coils from the radio, clean thouroughly with whatever cleaner floats your boat, and then spray the inside of the receiver casting with clear spraypaint or shellac. Once that's done, the radio will operate correctly until the end of its service life.
+++OK ATH
...replacing the entire datacenter floor where I work because of zinc Whiskers. We had the underfloor area cleaned for the new A/C that blows from the floor up. We promptly lost 11 power supplies and the total count is up over 20 now. We did verify the presents of zinc whiskers in the dead powersupplies thanks to the onsite electron microscope.
You sure they are zinc and not steel? We had similar problems decades ago, where we got intermittant random memory errors. Turns out the blowers on the bottom of the frame were sucking up steel fibers left from the cleaners using steel wool pads on those huge floor buffers. They were being blown through the core memory arrays (yeah, REAL core memory).
Heisenberg may have been here.
Yes, it's solder mask ReK was thinking of (though soldermask used to be applied via a silkscreening process). The "silkscreen" is the text applied to the board: reference designators ("J2", "C25", etc.), PCB part numbers, company names, et. al.
.005" or less.
Regarding mlyle's comments about solder mask: production quality has improved greatly over the past decade. The unmasked areas are getting progressively smaller as the board manufacturers' ability to meet tight tolerances improves. It is now common for the gap between the mask and the exposed pads to be
Another post suggested the application of conformal coating to the board. This would work, but the folks in production - who build and test the boards - really don't like to do that. For those who don't know what conformal coat is, it's a plastic-like coating that is applied (in liquid form) to a circuit board. Once it is cured, it provides a relatively effective barrier to moisture, oxygen and corrosive pollutants.
It adds cost to the product, though, for several reasons: price of the coating material, man-hours spent masking areas not to be coated, applying the coating, sending it to cure, retrieving the cured boards, as well as added time spent repairing boards with faulty components found in the final board tests.
Personally, I support conformal coating boards - but then I'm a circuit board designer. The only work it adds for me is the addition of a note or two on the fabrication specs.
"A generation which ignores history has no past and no future." -- Robert Heinlein
This other page (from this /. comment) states that zinc whiskers are too small for normal dust filters, and it pretty much dismisses filtering as being a viable solution. (Of course, they're selling a non-filter solution so it's in their best interest to dismiss alternates...).
Check out Chad's News
NO.........We aren't stupid. My mom has been doing work with the electron microscope for more than 20 years now. you never re-use sample pads which is a standard rule when taking sample. Each sample was only used once and clearly marked where it was taken from so that they didn't get mixed up. In fact the power supply sample were taken a different day than the floor samples.
As I stated in a different post.....The electron microscope used for verification has a machine attached to it that can give you a breakdown of the metals in a givne sample. Each metal gives off a unique reading. It was very obviously zinc and not steel.