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Tin whiskers: What happens when they spontaneously erupt? (2018)

microcontrollertips.com

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Re: Tin whiskers: What happens when they spontaneously erupt? (2018)

#31

Post by Damogran6 »

State of Colorado Datacenters got them. The response to them were weird...if any machine were in any of the affected areas, they were persona non grata...they could never leave those datacenters as functional server.

It DID lever some money for an awesome off-site backup datacenter...which was eventually our only datacenter for 'reasons'.

In our case, I think one of the datacenter's raised floors got carpeted (don't judge, it predated me, I was equally baffled) and a grounding issue caused a voltage drift causing the tin to migrate...

Re: Tin whiskers: What happens when they spontaneously erupt? (2018)

#32

Post by MisterTea »

stefan_ wrote: post #25
robomartin wrote: post #9

I have dealt with the tin whisker problem in the context of aerospace applications (both space-borne and terrestrial flight), including extensive consulting with subject matter experts from NASA. The bottom line is quite simple: Tin whisker growth onset is a stochastic process. We cannot predict when it will start and we cannot prevent it. Once they start growing it is almost impossible to contain them. They will pok…

The Restriction of Hazardous Substances Directive (RoHS) is not about preventing garbage in landfills, and frankly it's been 18 years and the sky is not falling.

Yes but the parent is not stating that. They are stating that a "save the environment" effort is not very environmentally friendly if it makes more waste.

Re: Tin whiskers: What happens when they spontaneously erupt? (2018)

#33

Post by xmodem »

the-dude wrote: post #14
Flozzin wrote: post #10

Earlier quoted context omitted.

I wouldn't recommend this. If you do use lead soldering, make sure you don't breathe in any fumes.

The boiling point of lead is 1749 °C (3180 °F).

The boiling point of water is 100 °C, and yet my shower seems to produce an awful lot of steam despite not being anywhere close to that.

Re: Tin whiskers: What happens when they spontaneously erupt? (2018)

#34

Post by kadoban »

the-dude wrote: post #19
turminal wrote: post #16

Earlier quoted context omitted.

That by itself does not imply fumes cannot form at lower temperatures.

Great. If we follow this line, standing next to a roll of solder is just as dangerous. No need to fire up the iron. If lead was so easily dissolved into air, wouldn't we have had massive issues in electronics factories? I don't recall ever reading such a thing ( as opposed to painters madness for example ). Not a native speaker, probably doesn't translate too well.

Or you could just look at the actual material property that matters, which I believe is called vapor pressure.

Re: Tin whiskers: What happens when they spontaneously erupt? (2018)

#35

Post by adrian_b »

dmitrygr wrote: post #4

Use lead solder, like NASA does: easier to use, and no whisker issues. Just wash your hands afterwards

Besides lead, there is a second element which greatly reduces the risk of tin whiskers, when alloyed to tin: antimony.

However the proposals of replacing the tin-lead alloys withe tin-antimony alloys have been rejected due to the fear that antimony is also toxic.

While antimony in high doses is indeed quite toxic, it is less dangerous as a pollutant than lead, because it does not have the same tendency for very long time accumulation in animal bodies and such a strong effect on the nervous system.

Re: Tin whiskers: What happens when they spontaneously erupt? (2018)

#36

Post by jccooper »

prutschman wrote: post #7

Could potting prevent this, or can the whiskers "push through" epoxy?

Yes; satellite boards tend to have conformal coatings, it helps but it's not a complete solution. (The coatings also help avoid shorts from junk floating around, and launch vibration.) Because of the inherent unreliability and difficulty in replacement, they also try really hard to avoid lead-free solder requirements.

Re: Tin whiskers: What happens when they spontaneously erupt? (2018)

#37

Post by mmastrac »

dmitrygr wrote: post #15
mmastrac wrote: post #6

Earlier quoted context omitted.

Better to solve these issues long-term. Lead's external costs in full product lifecycles are just too high.

As you read in TFA, there is no known solution, nor even a known cause for whiskers

No known cause or solution _yet_

Re: Tin whiskers: What happens when they spontaneously erupt? (2018)

#38

Post by xmodem »

robomartin wrote: post #9

I have dealt with the tin whisker problem in the context of aerospace applications (both space-borne and terrestrial flight), including extensive consulting with subject matter experts from NASA. The bottom line is quite simple: Tin whisker growth onset is a stochastic process. We cannot predict when it will start and we cannot prevent it. Once they start growing it is almost impossible to contain them. They will pok…

Do you happen to know if tin whiskers have anything to do with passing current? (in other words, will a device that's in constant use develop them faster than a physically identical device that's switched off and in storage)

Re: Tin whiskers: What happens when they spontaneously erupt? (2018)

#39

Post by tejohnso »

This is very surprising to me. I had no idea that certain conductors had some kind of (stochastic, according to robomartin) built-in time delayed short circuit mechanism that will, without question, manifest itself given enough time.

Like some kind of natural electronics prank.

Re: Tin whiskers: What happens when they spontaneously erupt? (2018)

#40

Post by mcguire »

the-dude wrote: post #19
turminal wrote: post #16

Earlier quoted context omitted.

That by itself does not imply fumes cannot form at lower temperatures.

Great. If we follow this line, standing next to a roll of solder is just as dangerous. No need to fire up the iron. If lead was so easily dissolved into air, wouldn't we have had massive issues in electronics factories? I don't recall ever reading such a thing ( as opposed to painters madness for example ). Not a native speaker, probably doesn't translate too well.

"Results showed that the mean PbB concentration of the exposed workers (6.12 +4.61 µg/dl) was significantly higher than that of the unexposed workers (4.63+3.91 µg/dl ) (z = 4.96; p = 0.001). There was a significant association between the blood lead concentrations with the exposure to lead (2 = 437.72; p = 0.001)." (https://www.researchgate.net/publication/271077842_Occupatio...)

"Epidemiological and experimental studies indicate that chronic exposure resulting in blood lead levels (BLL) as low as 10 µg/dL in adults are associated with impaired kidney function, high blood pressure, nervous system and neurobehavioral effects, cognitive dysfunction later in life, and subtle cognitive effects attributed to prenatal exposure. Pregnant women need to be especially concerned with reducing BLL since this can have serious impact on the developing fetus." (https://www.osha.gov/lead/health-effects)

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