Lead Free solder , Sn Ag & Cu

[saint gillis]

  Hello there are several lead free solder alloys available, the most commons being :
- Sn99,3Cu0,7
- Sn99Ag0,3Cu0,7
- Sn96,5Ag3Cu0,5
Etc..

  Does anyone know what are the advantages or disadvantages of getting such or such dose of Ag, Cu etc ?

 

[JohnRoberts]

  Hello there are several lead free solder alloys available, the most commons being :
- Sn99,3Cu0,7
- Sn99Ag0,3Cu0,7
- Sn96,5Ag3Cu0,5
Etc..

  Does anyone know what are the advantages or disadvantages of getting such or such dose of Ag, Cu etc ?

The main advantage is being lead free... (ROHS compliant).

JR

 

[ruffrecords]

https://securityelectronicsandnetworks.com/2020/07/31/lead-free-or-leaded-solder-whats-best/

Cheers

Ian

 

[gyraf]

I find that the Sn99,3Cu0,7 is the most predictable to work with - both in terms on how it behaves in the soldering process and in how many post-the-fact errors I detect..

But as always ymmv

/Jakob E.

 

[abbey road d enfer]

I find that the Sn99,3Cu0,7 is the most predictable to work with - both in terms on how it behaves in the soldering process and in how many post-the-fact errors I detect..

But as always ymmv

/Jakob E.

I find that all lead-less solders are predictably unrewarding, in the sense they all look dry, the don't wet well and make blobs and whiskers. 
Now, of course, my employees use lead-less, but I use leaded. I'm not gonna change after 60 years of blanketing my lungs.  ;D
I would think that the most unhealthful part is inhaling rosin fumes, which is about the same whatever the metallic composition.

 

[ruffrecords]

I find that all lead-less solders are predictably unrewarding, in the sense they all look dry, the don't wet well and make blobs and whiskers. 

A decade or so ago when it was first planned to phase out leaded solder I purchased a lifetimes supply of the stuff only to find that it is still available!

Cheers

Ian

 

[JohnRoberts]

I used lead free solder in my current drum tuner. I have both leaded and lead free solder on my bench. I use lead free for final assembly solder joints for EU market... but I don't like it.

JR

 

[john12ax7]

I find that the Sn99,3Cu0,7 is the most predictable to work with - both in terms on how it behaves in the soldering process and in how many post-the-fact errors I detect..

But as always ymmv

/Jakob E.

Interesting,  will need to give that a shot.  Been using Kester 275 thus far which is Sn96,5Ag3Cu0,5

 

[Whoops]

I also tried out Lead-Free solder when here in EU the measures were applied. I found it hard to solder and never liked the results.

I then realized like Ian that the good old Lead solder was still available in electronic shops for repair duties, and still buy 60/40 Lead solder and really like it.

Being it the lead or the rosin fumes I really really advice anyone to have a fume extractor while soldering, the fumes are really toxic. You can buy one, or even build a DIY one it's easy, there's also cheap options with just a small fan an a carbon activated filter that are efficient of small DIY duties.

 

[rackmonkey]

You’ll never pry my brain-eating 64/36 lead solder from my hands. The lead-free stuff - every formulation I’ve tried - is inferior in every way. But especially where it comes to disassembly/de-soldering. It can be nearly impossible to remove without a good desoldering gun (forget using solder wick with it). Altec started using it in the 70s and 80s and I dread working on any of that stuff for that reason. I usually have to apply some lead solder over the joint and then desolder. Even then, it can be dicey.

Just get some good ventilation and stick with the good stuff. My 2 cents.

 

[Tubetec]

More or less the same experience as the rest of you , lead free never looks as good a joint . I've never tested the resistance but Im willing to bet a lump of crud doesnt contact nearly as well as the shiney concave like you get with lead based product. Extra flux paste may help with removal but sometimes the metals are so badly oxidised thats no good . Best way I found to clean away dead lead free solder is simply flood the joint with fresh leaded solder until everything is flowing again then get in quick with the sucker , now your pad should also clean up nicely with wick. My guess is there a whole host of compatibilty issues with various formulations of metals and fluxes found in modern gear. Another point that deserves mention is working temp , Ive generally found lead free needs a higher iron tip temp to flow, that translates into more stress on components more chance of damaging the board and higher subsequent failure rate in service.

Consumer electronics in the modern age most likely has only to live a year or two before its unceremoniously dumped, shonkey goods helps with the roll out of new products , with most people happy to contrive this as 'progress' in their minds.  The actual environmental cost is offset against the marketing and ad revenue potential of these gadgets, 40 inch 4k oled tv less than 400 euros. I suppose it could be argued the main people the Rohs helps is the people in the factories and the people who end up picking over and dismantling our electronic scrap mountain.

 

[Ricardus]

I haven't tried any ROHS solders yet, and based on things I've seen here and elsewhere I see no reason to, as long as what I like is still available. My dad is a maker from way back, so we have enough Kester 60/40 in the house to float a battleship, and I used that for years. But a friends who works for NASA and who solders things that fly in space talked me into something from ChipQuik. It's 62/36/2 - Sn/Pb/Ag

Even that little difference causes it to flow and wick differently than the 60/40, but I really like it.

 

[Gold]

It's 62/36/2 - Sn/Pb/Ag

That's silver bearing solder. That's the correct stuff to use on anything silver plated. I use it it for most stuff that isn't silver plater too. When I don't use that I use 63/37 eutectic solder. It doesn't stay in a liquid state as long as 60/40. It's better for stuff that isn't physically secure. Less chance of a cold solder joint.

 

[Rusan]

  You mean they make something besides Kester 44?

Actually, I once tried some Radio Shack Sn96/Ag4 or something like that, and while I found it acceptably OK for point-to-point circuits, it didn't want to wet the pads and leads very well on thru-hole PCBs, and left lots of tiny whiskers.  I wouldn't even attempt to use it on anything SMD.

But, that's how I roll.  I make, record and listen to music through tubes, write with a fountain pen (that I made myself), shave with a straight razor, use hot hide glue in my handmade wood crafts, have a nice vintage LP and cassette collection, use an alarm clock and a MP3 player instead of my phone, and am bitterly clinging to my leaded solder. Now, where's that phone book at?...

Joking aside, my aforementioned experiences with lead-free solder weren't very pretty (pun intended), and I'm sure it's probably given electronics manufacturers plenty of headaches as well as likely reducing the reliability of said electronics.  But nevertheless, I completely understand the need for limiting the amount of toxic metals in consumer electronics that often end up in landfills.  I just don't understand why the EU is so picky about the tiny amounts of lead in consumer electronics, when there are at least a billion lead-acid car batteries in Europe?

 

[Ricardus]

That's silver bearing solder. That's the correct stuff to use on anything silver plated. I use it it for most stuff that isn't silver plater too. When I don't use that I use 63/37 eutectic solder. It doesn't stay in a liquid state as long as 60/40. It's better for stuff that isn't physically secure. Less chance of a cold solder joint.

Yeah, that's what my NASA friend said. They aren't allowed to solder with things that are not non-eutectic. Does that sound right?

I'm using it on everything.

 

[evil grill]

...

Joking aside, my aforementioned experiences with lead-free solder weren't very pretty (pun intended), and I'm sure it's probably given electronics manufacturers plenty of headaches as well as likely reducing the reliability of said electronics.  But nevertheless, I completely understand the need for limiting the amount of toxic metals in consumer electronics that often end up in landfills.  I just don't understand why the EU is so picky about the tiny amounts of lead in consumer electronics, when there are at least a billion lead-acid car batteries in Europe?

And all the mercury from the low energy lamps! Toxic stuff!

 

[gyraf]

..because consumer electronics has a tendency of ending up as landfill waste, the 37% lead in solder is possibly critical, and I accept this as better-safe-than-sorry environmental protection rules. Car batteries must go to reuse of lead, absolutely no legal way around this ending for those.

If we must complain about the rules, then what I don't understand is the ban on optical compressors generally on the grounds of MICROGRAMS of cadmium in a photocell that rarely (if ever) ends up as landfill.

/Jakob E.

 

[Rusan]

..because consumer electronics has a tendency of ending up as landfill waste, the 37% lead in solder is possibly critical, and I accept this as better-safe-than-sorry environmental protection rules. Car batteries must go to reuse of lead, absolutely no legal way around this ending for those.

If we must complain about the rules, then what I don't understand is the ban on optical compressors generally on the grounds of MICROGRAMS of cadmium in a photocell that rarely (if ever) ends up as landfill.

/Jakob E.

Ah yes, that's right, car batteries must by law be recycled here in the U.S. as well.  I'd forgotten about that.  I recall driving somewhere once and passing by a business that collected car batteries; besides other piles, there was a pile in front of the building about 10 or so meters in diameter and 3 meters high.

Yep, we must ban those few micrograms of cadmium sulfide in that photocell, when there are untold TONS of old anti-corrosion cadmium plating and primer all over every square kilometer of the entire European continent.  Don't feel alone, our government does stuff just like that too.  It's no coincidence that a group of baboons is called a "congress."  :

Rusan   

 

[Tubetec]

How the low energy CFL lighbulbs got adopted as environmentally friendly really does show the crooked power of the lobbyists and the utter ineptitude and shortsightedness of politicians . The vast majority of people have no idea that if a CFL bulb is smashed in your house you need to open doors and windows and leave the area while the mercury vapour escapes. Led lamps arent without their own downsides either .
https://www.scientificamerican.com/article/led-lightbulb-concerns/

For years and years we were able to export troublesome waste to poorer places for disposal, that is fast coming to an end meaning down the line were gonna end up stuck with a growing pile of dangerous crap. The WEEE directive is a total p!ss take, obliging the sellers to take back like for like , in the case of used CFL's theres simply tossed into a skip out back and broken ,the noxious content swept into the air and water courses. The safety of Led type bulbs in the disposal chain  ,as far as I can see very much depends on construction, some are well contained in a glass or plastic envelope with others types much more likely to leech their toxic load into the environment. From all we've seen in relation to CFL bulbs disposal ,absolutely no reason to believe Led lamps will end up disposed of appropriately either.

 

[Gold]

Yeah, that's what my NASA friend said. They aren't allowed to solder with things that are not non-eutectic. Does that sound right?

I'm using it on everything.

Sounds right. I keep 62/36/2 and 67/37 in thin gauge and thick gauge on the bench. The silver solder in generally first choice. I just got both rolls of thin gauge delivered today as I ran out last week. It always surprises me when I go through a whole roll of solder.