3 ms·

I am teaching art students with Sn96,5Ag3,0Cu0,5 (Felder iso-core clear) solder. They all tend to do pretty good after a few hours. Soldering temperature needs

by atoav 4y ago

I am teaching art students with Sn96,5Ag3,0Cu0,5 (Felder iso-core clear) solder. They all tend to do pretty good after a few hours. Soldering temperature needs to be higher, and using one of those fancier soldering stations where the temperature sensing element is directly in the tip instead of somewhere in the shaft makes a ton of sense (to avoid temperature dips). I think soldering with lead free can indeed be harder, but for teaching that means the people will have to learn the right technique. It is much easier to do it wrong and still get something that looks ok using leaded solder. And if they don't have the comparison they won't complain ; ) I will have to check out the bismuth solder nonetheless.

avian 4y ago
I'm an electrical engineer and I just spend the whole day yesterday reworking some factory-made Sn/Cu/Ag boards in the lab. What kind of parts are you soldering? Thru-hole parts are easy. Surface-mount parts can go quickly from annoying to very hard/nearly impossible to work with Sn/Cu/Ag, depending on their size and thermal sinking ability. Sn/Cu/Ag solder has a narrow window where the solder is melted and wets pads but the FR4 substrate isn't yet degrading. If you have sensitive plastic parts like connectors, etc. the window is even narrower. This is doable in an industrial reflow owen. However when doing hand work or repair, it's impossible to control the temperature this well. For example, after years of experience, I'm still unable to desolder large BGA or PGA parts without visibly degrading the board (i.e. there's usually a brown mark left on it - unfortunately the boards I commonly work with these days use white soldermask, which makes this even more obvious). That's with a temperature controlled pre-heater and a hot-air station. I won't even attempt to solder such parts manually with Sn/Cu/Ag.

by atoav 4y ago

avian 4y ago

I'm an electrical engineer and I just spend the whole day yesterday reworking some factory-made Sn/Cu/Ag boards in the lab. What kind of parts are you soldering? Thru-hole parts are easy. Surface-mount parts can go quickly from annoying to very hard/nearly impossible to work with Sn/Cu/Ag, depending on their size and thermal sinking ability. Sn/Cu/Ag solder has a narrow window where the solder is melted and wets pads but the FR4 substrate isn't yet degrading. If you have sensitive plastic parts like connectors, etc. the window is even narrower. This is doable in an industrial reflow owen. However when doing hand work or repair, it's impossible to control the temperature this well. For example, after years of experience, I'm still unable to desolder large BGA or PGA parts without visibly degrading the board (i.e. there's usually a brown mark left on it - unfortunately the boards I commonly work with these days use white soldermask, which makes this even more obvious). That's with a temperature controlled pre-heater and a hot-air station. I won't even attempt to solder such parts manually with Sn/Cu/Ag.