3 ms·
You have to be careful when saying "silver" solder. For soft solder, the eutectic is SnAg3.5Cu0.9, which melts at 217C, 34C higher than the 63/37 eutectic Sn/P
by wrycoder 4y ago
You have to be careful when saying "silver" solder.
For soft solder, the eutectic is SnAg3.5Cu0.9, which melts at 217C, 34C higher than the 63/37 eutectic Sn/Pb. There's a lot of low cost lead-free solder out there which is essentially pure tin[0], with silver and copper content below 0.5 percent each. That melts even higher, at about 230C, and tends to be not eutectic, i.e. it has a pasty range.
I think you are talking about the eutectic alloys with about 3% silver. Good stuff, but the higher temperatures involved make it harder to use without damaging the components.
For repairing 20th century electronics and for general DIY electronics use, 63/37 is great, and flows better than 60/40 - just wash your hands afterwards.
For repairing 21st century electronics, use lead-free for compatibility.
https://en.wikipedia.org/wiki/Tin-silver-copper https://en.wikipedia.org/wiki/Tin-silver-copper
Also, to many people, saying "silver solder" means a silver-copper high temperature brazing alloy, which is a whole different thing. Better to say "tin-silver solder" or "tin-silver".
Edit: See also this entry on degradation of pure tin electronic connections[0]
[0] https://en.wikipedia.org/wiki/Tin_pest#Modern_tin_pest_since_adoption_of_RoHS https://en.wikipedia.org/wiki/Tin_pest#Modern_tin_pest_since...
- bmitc 4y agoI am just beginning to solder, and I am committed to using non-leaded solder. After some research, I have settled on SN100C, but I haven't used it yet. https://aimsolder.com/products/solder-alloys/sn100c https://aimsolder.com/products/solder-alloys/sn100c
- bmitc 4y agoNot sure about the downvotes. Is this bad solder or something? Don't try to convince me about leaded solder, please.
- ansgri 4y agoProbably because you haven't used it yet. Would like to hear from you after having some experience with it though.
- bmitc 4y agoI guess so. But there's nothing I can do about that right now sans going to the future, as I'm still acquiring the pieces. Haha. I was trying to just make it clear that this was a choice was due to research and not use, as of yet.
- wrycoder 4y agoNo idea, but I'll give you an upvote for joining in! The tin solder you mentioned is 99% tin and has a very high melting point, so you'll have to be careful with hand soldering not to cause heat damage. You can also expect rework to be difficult, with lots of burned flux. The photos at your link show some gorgeous joints, so good luck! It may be that the trace amounts of Ge in the solder will help with joint longevity. Since I don't do production soldering, and cost isn't really a consideration for me, I use 3% silver alloy to keep the temperatures down, when I'm not using 63/37. Kester solder listing: https://www.kester.com/knowledge-base/lead-free-solutions#47056-lead-free-alloys https://www.kester.com/knowledge-base/lead-free-solutions#47...