Tin Whiskers

[LektroiD]

A few years ago I found a series of videos, each about a minute long talking about tin-whiskers caused by Lead-Free solder and the effects they have. I was wondering if anyone has any more information on this, or links to videos about this phenomenon. I'll link what I have below, but seems this is the only videos ever been made about it. I wonder which documentary these are from...

[T3sl4co1l]

That's the narrator voice from Modern Marvels, History Channel.

It seems much of the lead-free scare hasn't come to pass.  Although lead-free processes must be more tightly controlled, the end product (of good processing) is *enhanced* reliability.  It is a stronger differentiator, so that poorly controlled processes tend to fail more readily (which was the problem documented there).

Not to say it's not a concern; it certainly is.  But it also hasn't produced the "sky is falling" results that it was claimed to; consumer crap continues to be thrown out in the 90 days to 3 years timescale that it has always been, and things that randomly last longer than that.

Tim

[KD0CAC John]

Here is a NASA study I found yrs. ago , a PDF if you want .
http://nepp.nasa.gov/whisker/

[f5r5e5d]

funny, spending $10 Millions per major electronic OEM and causing avionics failures, a nuke power plant shutdown isn't a "problem" - when the environmental protection goals could have been met/exceeded at lower cost with a rational regime?

http://paris.utdallas.edu/IEEE-RS-ATR/document/2008/2008-19.pdf

[Stonent]

Between RoHS and bad caps, I think we've got the diagnosis for 75% of all electronics failures in the last 10 years.

[Rick Law]

Well, look at it this way - if one more person is killed by failed electronics due to whiskers, one less person is available to die of lead poisoning.  So, we are gaining ground.

Talking about death is upsadding.  I need some comfort food.  Where is my roll of rosin flavored solder?  That pine gum taste really takes the edge off.

[rolycat]

Talking about death is upsadding. 

It is, it is indeed.

On an upcheering note, you have embiggened our vocabularistic repertoire with your cromulent neologism.

[Rick Law]

Talking about death is upsadding. 

It is, it is indeed.

On an upcheering note, you have embiggened our vocabularistic repertoire with your cromulent neologism.

Oh, well, error on my part!  This one I "corrected" from the correct word to the wrong one.  Very careless of me.   While this is only a forum, looking stupid is... well, stupid.

Your criticism is well grounded.  I do think I would have benefited had I learned English better.  While my career (in the USA) was ok, but I know I could have done better had I wrote better.  Sometimes, particularly when I am tired or in too much of a hurry, my writing really make me look stupid.

[jlmoon]

Talking about death is upsadding. 

It is, it is indeed.

On an upcheering note, you have embiggened our vocabularistic repertoire with your cromulent neologism.

Metaphorically speaking cromulent is such a confusicating term with such embiggenment!

[rolycat]

Talking about death is upsadding. 

It is, it is indeed.

On an upcheering note, you have embiggened our vocabularistic repertoire with your cromulent neologism.

Oh, well, error on my part!  This one I "corrected" from the correct word to the wrong one.  Very careless of me.   While this is only a forum, looking stupid is... well, stupid.

Your criticism is well grounded.  I do think I would have benefited had I learned English better.  While my career (in the USA) was ok, but I know I could have done better had I wrote better.  Sometimes, particularly when I am tired or in too much of a hurry, my writing really make me look stupid.

It wasn't a criticism - more of an appreciative jest. I do happen to think that upsadding is a fine word - cromulent, in fact 

[T3sl4co1l]

Spoilers: "cromulent" and "embiggening" are from The Simpsons.

[coppice]

Tin isn't the only metal with whisker growth issues. Zinc and cadmium were causing trouble in electrical and electronic equipment before it was even realised that tin could also form whiskers. I've seen some amazing bundles of whiskers on zinc coatings that looked like grey cotton wool.

[rolycat]

Spoilers: "cromulent" and "embiggening" are from The Simpsons.

Well, they were from The Simpsons. Since their debut there in 1996 they have started cropping up in print, possibly to show that the author is a happening kind of dude(tte). Nothing wrong with neologisms - Shakespeare was a prolific source, of course (of course).

Back on topic, it does seem weird that after all the study devoted to them we still don't know the mechanism of whisker formation.

[TimFox]

Tin isn't the only metal with whisker growth issues. Zinc and cadmium were causing trouble in electrical and electronic equipment before it was even realised that tin could also form whiskers. I've seen some amazing bundles of whiskers on zinc coatings that looked like grey cotton wool.

Also "dendritic silver" is a whisker growth issue in certain situations.

[T3sl4co1l]

We know quite a bit more about whiskers nowadays -- new research, that has lifted everyone up, so that from the highest NASA papers (linked earlier) to the lowliest of programs (also linked earlier), we now understand at least a little more, and what to do about it.

I would suggest looking for references since 2012.  Those NASA docs for example are 2009ish, and mostly reference materials even older (2000s and less).  Should be plenty from, like, IPC, IEEE, etc. out there?  (No, I don't have any to hand, unfortunately.)

If you're looking to get products manufactured, and your choice is leaded, or a lead-free process and formula that's unchanged since 2000... I'd go with lead any day.  Such are the same processes documented in those papers.

Tim

[Rick Law]

We know quite a bit more about whiskers nowadays -- new research

...

If you're looking to get products manufactured, and your choice is leaded, or a lead-free process and formula that's unchanged since 2000... I'd go with lead any day.  Such are the same processes documented in those papers.

Tim

Trouble is, we have a generation of folks programmed to think not only lead free, but that lead is evil  - to the point they are worried about breathing lead-fume during soldering.  And of course they have no idea about the reliability impact.

[f5r5e5d]

and in hiRel applications allowing lead it is now difficult to obtain parts - many now have to stripped, coated outside of the OEM process controls

[LektroiD]

We know quite a bit more about whiskers nowadays -- new research

...

If you're looking to get products manufactured, and your choice is leaded, or a lead-free process and formula that's unchanged since 2000... I'd go with lead any day.  Such are the same processes documented in those papers.

Tim

Trouble is, we have a generation of folks programmed to think not only lead free, but that lead is evil  - to the point they are worried about breathing lead-fume during soldering.  And of course they have no idea about the reliability impact.

I'll always use 60/40. I'm more concerned with breathing flux than lead fumes (that's if such a thing as 'lead fumes' exist)...

In a sense, RoHS is way worse when it comes to all the failed electronic waste in landfills. RoHS solder seems pointless anyway, it's not like the consumers are going to open their new TV and lick the PCB.

There's a lot worse substances being used than a little lead in solder to prevent whisker shorts, unless planned obsolescence is the agenda...

[savril]

Trouble is, we have a generation of folks programmed to think not only lead free, but that lead is evil  - to the point they are worried about breathing lead-fume during soldering.  And of course they have no idea about the reliability impact.

My concern is not to breath lead, due to the heavy mass of lead, it's unlikely to breath a signifiant amount of lead I think.

My concern is more about that :
https://www.google.fr/search?q=african+computer+recycle&biw=998&bih=761&source=lnms&tbm=isch&sa=X&ei=kVJJVev6Hc_base1gYgB&ved=0CAYQ_AUoAQ

There also on youtube videos from stupid people on how to get gold by melting chips. Not only there's the lead problem but there's also the halide which turn into dioxin while burning. Due to corrupt people, a significant amout of electronic waste will end burning like this and polluting for a long time a foreign country.
I do my part by not using leaded solder and I don't suffer from unacceptable bad soldering and I don't care if I may have tin whisker problem in 5-10 years, my design will probably be totally out of date by then. This make my life easier as I don't have to write in my testament "Please handle my electronic with care and send them to a proper recycle facility".

[Rick Law]

We know quite a bit more about whiskers nowadays -- new research

...

If you're looking to get products manufactured, and your choice is leaded, or a lead-free process and formula that's unchanged since 2000... I'd go with lead any day.  Such are the same processes documented in those papers.

Tim

Trouble is, we have a generation of folks programmed to think not only lead free, but that lead is evil  - to the point they are worried about breathing lead-fume during soldering.  And of course they have no idea about the reliability impact.

I'll always use 60/40. I'm more concerned with breathing flux than lead fumes (that's if such a thing as 'lead fumes' exist)...

...

That is exactly my point.  Lead doesn't evaporate at that low a temperature, but their phobia caused them to overlook the obvious (flux fumes) and instead scared to death of lead fume which is impossible at such a low temperature.

Might as well worry about lightning strikes while soldering.  That is at least more probable than lead fume.

[Rick Law]

Trouble is, we have a generation of folks programmed to think not only lead free, but that lead is evil  - to the point they are worried about breathing lead-fume during soldering.  And of course they have no idea about the reliability impact.

My concern is not to breath lead, due to the heavy mass of lead, it's unlikely to breath a signifiant amount of lead I think.
...

Lead in solder doesn't evaporate at such low temperature.  There is no chance lead-vapor can form and there is no possibly you can breath any "lead fume" in.

It is not merely unlikely.  It is impossible!

Imagine worry about steam burn because a dog walked into the swimming pool.  The dog's body temperature is warmer than water.  But even if a million dogs walked into the swimming pool, the warmth from that million dogs will not boil the water.

[T3sl4co1l]

Well, let's not be stupid here.

Any use of lead products inevitably produces dust, too.  Wiping or striking off the soldering iron produces small globs and dust.  It's not much, but it's more than zero.

Keep your work area separate from your eating area, and wash your hands inbetween.

Tim

[savril]

My concern is not to breath lead, due to the heavy mass of lead, it's unlikely to breath a signifiant amount of lead I think.
...

Lead in solder doesn't evaporate at such low temperature.  There is no chance lead-vapor can form and there is no possibly you can breath any "lead fume" in.

It is not merely unlikely.  It is impossible!

Imagine worry about steam burn because a dog walked into the swimming pool.  The dog's body temperature is warmer than water.  But even if a million dogs walked into the swimming pool, the warmth from that million dogs will not boil the water.

It's not that simple I think. If you look at your solder workspace, you'll see lot of little spots of solder balls more than 20 cm away from you solder area (depends on how much flux used). When I solder small SMT, I tend to be close to the PCB. There's a chance that nano part of lead will be pushed by hot air from boiling flux and that you can breathe it (because the force from evaporating flux may be enough to push small lead spheres). Boiling flux may be more likely to make lead jump from the board to your mouth. I'm not a lot educated in physics of materials but I think it may be possible. However the amount of contaminant involved in this case seems marginal I think.
That's why I'm more concerned about flux for the people doing the soldering (which you can hardly get any information from any solder or flux manufacturer, secret recipe if it is not pure rosin).

[PeterFW]

About "lead fumes" and "breathing in" lead...
Lead boils at way, way every imgainable temperature that is used to solder.
I do not know about the details but if the boiling point is around 1700° it can not be that much that gets airborne at 400°C (worst case).

There are a great number of people who regularly breath in real "lead fumes" and oxides. In moderation with proper ventilation but no respirators.
I am one myself and i do not know annyone who has had problems with that, even all the folks way past 75, all still alive.
Some claim to have had the doctors check their levels and they claim they were rather high, but folks talk all kind of crazy talk if they think they "know stuff".
And none of them had signs of lead posioning.

Edit:
Ok, lets say "acute lead posioning", today people are all wonky in the head annyway, maybe that is caused by long time lead exposure

Yes, lead is a tad bad for you but not nearly as much as you think, at least over two to three generations. Maybe future generations will walk around with a third arm, who knows.

Water contamination through lead in the soil is very, very unlikely.
I know a few contaminated areas were the ground water regularely checked, not a single problem.
One heavily contaminated local forrest has even been declared a wildlife preserve to my knowledge, because all the little critters and plants are very happy to live there because filthy humans dont bother them and are all healthy...

[LabSpokane]

In short, lead is toxic. The main problem isn't immediate death. The problem is that continued exposure causes long term health and mental developmental problems - particularly in children.

For anyone who doubts the human health effects of chronic lead exposure, you are hereby cordially invited to our nearby Superfund Cleanup site at Kellogg, Idaho, USA. In the 1980's, the children tested there has the highest blood concentrations of lead in the world. Many of those exposed are still there today. Come see the results and feel free to arrive at your own conclusions.

We also have a bonus side trip! We'll go for a bike ride down the valley from the cleanup site where you can see acre after acre of dead swans - who die from eating the lead-laden mud that covers the tubers that are a food source.

---------

Please do not interpret the above as an endorsement of RoHS.