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> Not sure about what they're saying about the solder though. There's more than one solder alloy in use. There's more than one class of solder alloy in use. So

> Not sure about what they're saying about the solder though. There's more than one solder alloy in use. There's more than one class of solder alloy in use. Some are easier to use, some are harder to use. Some are high-performance, low-tolerance, some are low-performance, high-tolerance. Some are expensive, some are cheap. The most troublesome family is SnBi. These are relatively new. They have a big "greenwashing" problem in that they solder at lower temperatures, which is "environmentally friendly" (and cheaper to run). Also the base metal is dirt cheap. (Wonder why manufacturers are interested?) It's also very, very brittle. It also happens to be a low-temperature alloy... so it's much easier to get hot enough to desolder during operation. Lots of trouble all around and in general a very high field failure rate. Not recommended... oh wait but it's cheap and greenwashable. Sigh.

userbinator 3y ago
I won't ever forget the widespread BGA failures caused by the RoHS-forced switch to lead-free solder. No doubt massive amounts of additional ewaste were created, but at least it's "environmentally friendly" ewaste? Military/aerospace are still exempt and continue to use leaded solder.
- qiqitori 3y ago
  I don't want to pick a fight, but here's my rando opinion on that: Almost all electronic devices end up as e-waste after a few years. If a couple % fail prematurely, that doesn't create a massive amount of additional ewaste, but rather a _very_ slight increase in e-waste. And it's relatively benign e-waste. You could shred the board and sprinkle it over your field and it wouldn't be a huge problem (* don't take my word on this; there's flux residue and somewhat toxic stuff used in other components, the plastics will probably leak BPA and other stuff, etc.)
- imtringued 3y ago
  If you are talking about Nvidia's flip chip problems. Those were actually caused by the glue holding the chip onto the substrate, not the solder. The glue expanded at a different rate from the solder balls and caused them to crack. This was especially the case on consoles. People kept reballing and doing other useless repairs that solved the problem by accident by melting the solder balls between the substrate and the silicon chip. Some even managed to remelt the solder balls simply by replacing capacitors, which then made everyone think the capacitors were the problem and everyone swallowed it because replacement capacitors were cheap.
qiqitori 3y ago
Are there places that use SnBi for production devices? I know Bismuth alloys are used to desolder stuff (and they work amazingly well for that), but the general rule is that you should clean it up before soldering something new. (And keep it for later use, because it isn't exactly cheap.) It's a heavy metal and reading https://en.wikipedia.org/wiki/Bismuth#Toxicology_and_ecotoxicology https://en.wikipedia.org/wiki/Bismuth#Toxicology_and_ecotoxi... it looks like we don't know a lot about it yet, but to me it looks extremely unlikely to be better for the environment than SnAgCu. Also Bismuth appears to be rare: https://en.wikipedia.org/wiki/Abundances_of_the_elements_(data_page) https://en.wikipedia.org/wiki/Abundances_of_the_elements_(da... Rarer than palladium. All the even rarer elements are generally known to be rare and/or precious, or radioactive elements that normal people would never come across.
- exmadscientist 3y ago
  Lenovo had a lot of press releases about switching over. I don't know to what extent they actually did it. I agree it's probably not any better for the environment, but you know how the PR cycle goes.
- duskwuff 3y ago
  > it looks like we don't know a lot about it yet, but to me it looks extremely unlikely to be better for the environment than SnAgCu. Bismuth is quite safe. Pepto-Bismol (bismuth subsalicylate) is over 50% bismuth by mass, and it's sold over the counter.

userbinator 3y ago

I won't ever forget the widespread BGA failures caused by the RoHS-forced switch to lead-free solder. No doubt massive amounts of additional ewaste were created, but at least it's "environmentally friendly" ewaste? Military/aerospace are still exempt and continue to use leaded solder.

qiqitori 3y ago
I don't want to pick a fight, but here's my rando opinion on that: Almost all electronic devices end up as e-waste after a few years. If a couple % fail prematurely, that doesn't create a massive amount of additional ewaste, but rather a _very_ slight increase in e-waste. And it's relatively benign e-waste. You could shred the board and sprinkle it over your field and it wouldn't be a huge problem (* don't take my word on this; there's flux residue and somewhat toxic stuff used in other components, the plastics will probably leak BPA and other stuff, etc.)
imtringued 3y ago
If you are talking about Nvidia's flip chip problems. Those were actually caused by the glue holding the chip onto the substrate, not the solder. The glue expanded at a different rate from the solder balls and caused them to crack. This was especially the case on consoles. People kept reballing and doing other useless repairs that solved the problem by accident by melting the solder balls between the substrate and the silicon chip. Some even managed to remelt the solder balls simply by replacing capacitors, which then made everyone think the capacitors were the problem and everyone swallowed it because replacement capacitors were cheap.

qiqitori 3y ago

Are there places that use SnBi for production devices? I know Bismuth alloys are used to desolder stuff (and they work amazingly well for that), but the general rule is that you should clean it up before soldering something new. (And keep it for later use, because it isn't exactly cheap.) It's a heavy metal and reading https://en.wikipedia.org/wiki/Bismuth#Toxicology_and_ecotoxicology https://en.wikipedia.org/wiki/Bismuth#Toxicology_and_ecotoxi... it looks like we don't know a lot about it yet, but to me it looks extremely unlikely to be better for the environment than SnAgCu. Also Bismuth appears to be rare: https://en.wikipedia.org/wiki/Abundances_of_the_elements_(data_page) https://en.wikipedia.org/wiki/Abundances_of_the_elements_(da... Rarer than palladium. All the even rarer elements are generally known to be rare and/or precious, or radioactive elements that normal people would never come across.

exmadscientist 3y ago
Lenovo had a lot of press releases about switching over. I don't know to what extent they actually did it. I agree it's probably not any better for the environment, but you know how the PR cycle goes.
duskwuff 3y ago
> it looks like we don't know a lot about it yet, but to me it looks extremely unlikely to be better for the environment than SnAgCu. Bismuth is quite safe. Pepto-Bismol (bismuth subsalicylate) is over 50% bismuth by mass, and it's sold over the counter.