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Tin whiskers are a fact [1] and a reason why military and space applications only use leaded solder. I want my electronics to be reliable and last a long time,

Tin whiskers are a fact [1] and a reason why military and space applications only use leaded solder. I want my electronics to be reliable and last a long time, which is why I'll never use lead-free solder. Leaded solder is safe as long as you take basic precautions (e.g. use a fume extractor, wear gloves, don't lick the solder [2]). [1] https://nepp.nasa.gov/whisker/ https://nepp.nasa.gov/whisker/ [2] https://www.edn.com/analog-guru-jim-williams-dies-after-stroke/ https://www.edn.com/analog-guru-jim-williams-dies-after-stro...

deleted 7y ago
[deleted]
postalrat 7y ago
I figured the fume extractor is for flux fumes. Do the fumes also contain lead?
- deleted 7y ago
  [deleted]
- metroholografix 7y ago
  No, lead vaporizes at much higher temperatures than ones used for soldering. But the flux/rosin fumes are major lung irritants and can exasperate or even cause asthma.
  - shawnz 7y ago
    So where does the danger come from with leaded solder then? Skin contact?
    - foldr 7y ago
      Skin contact if you don't wash your hands. But more seriously, ingestion of small pieces of solder. Little balls of solder get everywhere in the surrounding environment.
IndrekR 7y ago
I wonder why new "we will all die to tin whiskers" articles stopped appearing 5 years ago. It used to be a really big thing, but now even all the new military projects are RoHS without any issues. Did not get your link to Jim Williams article. Care to elaborate?
- potatochup 7y ago
  In my (limited) exposure of products failing in the field due to whiskers, the mitigations included coating the entire board in some kind of film, and changing layout to make the board less vulnerable in the first place. Probably designers just got good enough at that to the point where it doesn't matter
  - varjag 7y ago
    Conformal coating is not related to whiskers, it's to prevent condensation damage in certain applications. Used where it is called for regardless of solder type.
    - strbean 7y ago
      Some of the linked articles in this comment section claim that conformal coatings mitigate whisker shorting because the whiskers can't pierce the coating.
- exmadscientist 7y ago
  A lot of it has to do with the platings on component leads/terminations. Within the last 10 years it's become clear just how well component manufacturers have dialed things in. They had to go pretty far to do that, though. I know the amounts used are miniscule, but it still amazes me that cheap commodity ICs have leadframes plated with palladium and gold, and dirt cheap resistors have ruthenium in them. (All very, very expensive noble metals!)
- metroholografix 7y ago
  Jim Williams used to lick solder as he was soldering as did other old-timers. Another observed behavior was licking the thumb and wiping the joint immediately after soldering. Later he developed Parkinson's disease (probably related [1]) and died of a stroke. [1] https://www.ncbi.nlm.nih.gov/pubmed/20807691 https://www.ncbi.nlm.nih.gov/pubmed/20807691
BoorishBears 7y ago
For casual hobbyists I don’t agree it’s safe (I used to think so though) A professional is usually working in a dedicated workspace completely separate of a working area, and that distinction alone is important. Everyone is aware they should wash their hands after working with lead solder, but if you’re working where you live, it’s all too easy to contaminate areas that you often come in contact with. I remember trying to clean out my solder sucker one day and realizing the sucker was literally atomizing solder. Just cleaning that thing probably contaminated a good radius around my desk. And I mean you can say “just wipe down the desk”, but that’s where the hobbyist aspect comes in, a lot of people will do this on a desk with a keyboard and a mouse, maybe a carpet, a ton of places for little bits of solder to hide. They’re doing things that a professional probably wouldn’t do too, accidentally getting solder balls all over the place and stuff. I’ve decided it’s not worth the risk. 99% of my soldering is through hole components you could solder with your eyes closed. Most hobbyists are not doing the volume of soldering that any extra work with non leaded solder is going to be terrible anyways. And they’re also often not going to take precautions like wearing gloves and buying a fume extractor for the same reason
- exmadscientist 7y ago
  Environment is huge. Listen to this guy! If you're doing this in your kitchen, stay far, far away from lead. If you're doing this in your commercial building's electronics lab, where food and drink is prohibited, and there are only electronics people around... leaded solder is going to win. If you're doing this in your factory, where your processes are tightly dialed in and you're moving mountains of product... now you can use either one just as easily, so there's no reason to risk lead unless the customer or application demands it.
  - sverhagen 7y ago
    Naive question, but isn't it forbidden? How could an application ask for it?
    - bigcheesegs 7y ago
AngryData 7y ago
On the flip side, lead-free solder has gotten my last 3 GPUs on the cheap as 'non-working" when all they needed was 15 minutes in the oven to help reflow the solder.
- abandonliberty 7y ago
  Wait, what? How do you do this?
  - lonelappde 7y ago
    Put it in the oven at low heat to melt solder.
  - AngryData 7y ago
    Remove all the heat sinks and anything else you possible can, preheat an oven to 385 (might want to use a thermometer and some thermal mass if your stove kicks on real hard so you don't overheat), make some tinfoil balls/pyramids and use that to elevate your card above the board, make sure most of the mounted components face up, cook for 10-15 minutes, VERY CAREFULLY remove it, or just turn the oven off and let it cool down again so you don't risk knocking anything while it is semi-solid, reapply heatsinks with new paste and install and test. Sometimes they need a bit more time or a few degrees or to be done more than once, but it works most of the time. Do not get your oven too hot or you risk causing components to fall off, it isn't actually reaching full melting point, just close enough for solder cracks and tin whiskers to self-heal. I probably don't need to say this but don't do this with a card that works because it is a small risk. The key is keeping a stable temperature and not rushing it. Ive never had it fail on me, but that could just be luck of the draw.
amelius 7y ago
What if you clean it with IPA and use a coating? Could that help prevent whiskers?
reportingsjr 7y ago
Tin whiskers aren't the result of lead free solder. They are a result of the tin coating on component leads. If you take a close look at that nasa page you'll see that every photo is of just a component lead/termination. Tin plating has largely been replaced by tin alloys at this point which has more or less solved the whisker issue at a large scale. More info here: https://www.indium.com/blog/pb-free-solders-are-not-the-cause-of-tin-whiskers.php https://www.indium.com/blog/pb-free-solders-are-not-the-caus...
- lonelappde 7y ago
  Unfortunate homograph there at "lead".

deleted 7y ago

[deleted]

postalrat 7y ago

I figured the fume extractor is for flux fumes. Do the fumes also contain lead?

deleted 7y ago
[deleted]
metroholografix 7y ago
No, lead vaporizes at much higher temperatures than ones used for soldering. But the flux/rosin fumes are major lung irritants and can exasperate or even cause asthma.
- shawnz 7y ago
  So where does the danger come from with leaded solder then? Skin contact?
  - foldr 7y ago
    Skin contact if you don't wash your hands. But more seriously, ingestion of small pieces of solder. Little balls of solder get everywhere in the surrounding environment.

IndrekR 7y ago

I wonder why new "we will all die to tin whiskers" articles stopped appearing 5 years ago. It used to be a really big thing, but now even all the new military projects are RoHS without any issues. Did not get your link to Jim Williams article. Care to elaborate?

potatochup 7y ago
In my (limited) exposure of products failing in the field due to whiskers, the mitigations included coating the entire board in some kind of film, and changing layout to make the board less vulnerable in the first place. Probably designers just got good enough at that to the point where it doesn't matter
- varjag 7y ago
  Conformal coating is not related to whiskers, it's to prevent condensation damage in certain applications. Used where it is called for regardless of solder type.
  - strbean 7y ago
    Some of the linked articles in this comment section claim that conformal coatings mitigate whisker shorting because the whiskers can't pierce the coating.
exmadscientist 7y ago
A lot of it has to do with the platings on component leads/terminations. Within the last 10 years it's become clear just how well component manufacturers have dialed things in. They had to go pretty far to do that, though. I know the amounts used are miniscule, but it still amazes me that cheap commodity ICs have leadframes plated with palladium and gold, and dirt cheap resistors have ruthenium in them. (All very, very expensive noble metals!)
metroholografix 7y ago
Jim Williams used to lick solder as he was soldering as did other old-timers. Another observed behavior was licking the thumb and wiping the joint immediately after soldering. Later he developed Parkinson's disease (probably related [1]) and died of a stroke. [1] https://www.ncbi.nlm.nih.gov/pubmed/20807691 https://www.ncbi.nlm.nih.gov/pubmed/20807691

BoorishBears 7y ago

For casual hobbyists I don’t agree it’s safe (I used to think so though) A professional is usually working in a dedicated workspace completely separate of a working area, and that distinction alone is important. Everyone is aware they should wash their hands after working with lead solder, but if you’re working where you live, it’s all too easy to contaminate areas that you often come in contact with. I remember trying to clean out my solder sucker one day and realizing the sucker was literally atomizing solder. Just cleaning that thing probably contaminated a good radius around my desk. And I mean you can say “just wipe down the desk”, but that’s where the hobbyist aspect comes in, a lot of people will do this on a desk with a keyboard and a mouse, maybe a carpet, a ton of places for little bits of solder to hide. They’re doing things that a professional probably wouldn’t do too, accidentally getting solder balls all over the place and stuff. I’ve decided it’s not worth the risk. 99% of my soldering is through hole components you could solder with your eyes closed. Most hobbyists are not doing the volume of soldering that any extra work with non leaded solder is going to be terrible anyways. And they’re also often not going to take precautions like wearing gloves and buying a fume extractor for the same reason

exmadscientist 7y ago
Environment is huge. Listen to this guy! If you're doing this in your kitchen, stay far, far away from lead. If you're doing this in your commercial building's electronics lab, where food and drink is prohibited, and there are only electronics people around... leaded solder is going to win. If you're doing this in your factory, where your processes are tightly dialed in and you're moving mountains of product... now you can use either one just as easily, so there's no reason to risk lead unless the customer or application demands it.
- sverhagen 7y ago
  Naive question, but isn't it forbidden? How could an application ask for it?
  - bigcheesegs 7y ago

AngryData 7y ago

On the flip side, lead-free solder has gotten my last 3 GPUs on the cheap as 'non-working" when all they needed was 15 minutes in the oven to help reflow the solder.

abandonliberty 7y ago
Wait, what? How do you do this?
- lonelappde 7y ago
  Put it in the oven at low heat to melt solder.
- AngryData 7y ago
  Remove all the heat sinks and anything else you possible can, preheat an oven to 385 (might want to use a thermometer and some thermal mass if your stove kicks on real hard so you don't overheat), make some tinfoil balls/pyramids and use that to elevate your card above the board, make sure most of the mounted components face up, cook for 10-15 minutes, VERY CAREFULLY remove it, or just turn the oven off and let it cool down again so you don't risk knocking anything while it is semi-solid, reapply heatsinks with new paste and install and test. Sometimes they need a bit more time or a few degrees or to be done more than once, but it works most of the time. Do not get your oven too hot or you risk causing components to fall off, it isn't actually reaching full melting point, just close enough for solder cracks and tin whiskers to self-heal. I probably don't need to say this but don't do this with a card that works because it is a small risk. The key is keeping a stable temperature and not rushing it. Ive never had it fail on me, but that could just be luck of the draw.

amelius 7y ago

What if you clean it with IPA and use a coating? Could that help prevent whiskers?

reportingsjr 7y ago

Tin whiskers aren't the result of lead free solder. They are a result of the tin coating on component leads. If you take a close look at that nasa page you'll see that every photo is of just a component lead/termination. Tin plating has largely been replaced by tin alloys at this point which has more or less solved the whisker issue at a large scale. More info here: https://www.indium.com/blog/pb-free-solders-are-not-the-cause-of-tin-whiskers.php https://www.indium.com/blog/pb-free-solders-are-not-the-caus...

lonelappde 7y ago
Unfortunate homograph there at "lead".