@nrp Hey Nirav,
I just thought of a issue, I would prefer to use leaded solder in all my expansion cards due to strength but that would mean I would not be able to import to the EU, side note on the FCC manual it says that says everything except memory use lead solder. May I get confirmation on what framework laptops use, and your suggestion on moving forward with solder mixtures?
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I thought that the issues with unleaded solder was that the mixtures were new and more prone to snapping. It’s been well over a decade since replacement mixtures have come out, and electronics sold globally appear to be reliable now that they’ve worked out the formulas (and even have formulas designed for specific use cases).
Lead was easier to work with, but are there still issues with unleaded in commercial applications?
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Yep, aircraft must have leaded as there have been air accidents regarding solder, the defence forces use it as its more robust. Plus higher temperatures.
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Ok… What about laptop failures in the EU? Most systems are sold with lead-free solder, and as far as I can tell the issues people have had historically don’t seem to be present. Are there known ongoing issues with lead-free systems from, say, the last four-to-six years?
And how many are connector-based failures that aren’t the result of abuse (i.e. because we plug-in and remove from ports, and USBC has been the standard on some phones for a while now)? I imagine that this would be a weak spot for devices using newer solder, and the Framework has an advantage of making connector damage less direct against he motherboard since it uses an adaptor that provides a buffer against mechanical failure/poor insertions.
I’m only challenging the idea to see where the business conversation might go and to better understand it. I’m not necessarily opposed to the idea; even if the Framework is designed to be component-level repairable, the issue being addressed is how to minimize the need for repair in the first place, and whether using lead is worth the trade-off vs. the environmental concerns.
The primary area where non-leaded solder joints would be at mechanical risk would have to be material fatigue. I would imagine that’s less of a concern when it comes to something like an expansion card, where you’ll see a couple hundred stress cycles, or perhaps a couple thousand in extremely frequent use situations. This is compared to the aviation industry and in defense applications, where high vibration from engines and reduced vibration damping needs leads to cycle counts in the millions.
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Yep I understand, but you cannot deny that leaded solder is much better as long as you do not snack on it or lick the solder you should be all right.
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In some cases unleaded is worse for your health due to the stronger rosin.
We always had trouble with the GE Master 100w radios… The pre-amp board bridge to the main amp board was just a solder lump. We were always replacing it with a copper plate and silver solder. Even lead solder didn’t work. Vibration is a bear.
My comment is that use what fits your needs. And yep, don’t lick it.
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Don’t lick it and use a good fume extractor 
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Yep, the fumes aren’t as bad as long as it’s not over the boiling point, still is good practice to use a fume extractor or even a 12v pc fan!
With all the varieties of solder we have there is no reason to use leaded solder unless its some very niche cases. Also toxic materials in consumer products aren’t seen positivly. This chart shows the steanght of different solder materials very well. 
There are also a lot of other solder that arn’t on this list like AuSn20 which has a tensile strenght of 39000 psi or 270 MPa. Indium based solder on the other hand are pretty soft and also more flexible
Lead is not toxic unless you ingest or inhale which you will be doing. Indium and other materials apart from the basic tin,lead,copper are the more expensive. Before you say I’m one of those people who just say something is bad by just looking at it, I’ve used lead free and know how bad it is, leaded is much nicer for SMD and THT work. Lead free solder can go black and detach from solder legs causing failure in the product and also has a shelf life due to the style of flux.
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From the comments in this thread, I guess whisker formation isn’t a problem anymore?
Not sure if solder joints going black is really a problem anymore. The most common failure of solder joints breaking is from too much stress for example from thermal expansion. Another one is the wrong combination of metals which can cause some reactions. Those things can be prevented though. All in all is solder joints breaking a pretty rare issue nowadays. Also some lead free solders can behave really nice for soldering. I personally never used leaded solder but some so i can’t talk from experience but some lead free solders are supposed almost as good as leaded ones. In case of PCB production has lead free one better properties than leaded solder. The shelf life of flux isn’t ideal but its also not too much of a problem
A nic isn’t an airplane, and rohs isn’t about “licking” by either techs or consumers. 63/37 is nice, but it’s hardly a big deal. I solder with plain old sac305 all the time, manually, even for tsop and bga, no problem. “car batteries are way more and electronics are 0.teeny%…” whiny-baby excuses. It’s just not that hard, unless you’re just not very good, but surely someone planning to produce a product for sale would not have just picked up an iron for the first time last week? For that matter… why is the solder even your problem anyway when you can order these kinds of things assembled right from the same pcb fabs these days?
On the note of PCB fabs, I’m trying to keep production of my cards in Australia. Prices will be way too high for assembly so its hand assembly. Aswell as the PCBs.