Lead-Free soldering equipment?

Hello Steve,

Solder manufacturers will hardly recommend irons. You have to go to the sites of manufacturers of irons such as Weller. Their silver series is advertised as more suited for lead free, mainly because of the use of higher power elements.

However, it depends of what you want to solder. The Weller stations here have variable temperature, meaning there is a potmeter up front. So I don't really see any problems there or why we'd have to buy new irons. I have seen people light a cigarette with an ordinary Weller iron. Not allowed around here though. For really big stuff there is a 500W big Bertha in the closet. For really, really big stuff we still have that blow torch ;-)

Regards, Joerg

If you need to do wire soldering, I have investigated many SAC305 wires, and can tell you that the best by far is Kester's SAC305 #66/48 (that means flux type 48, with 3% concentration.)

The #58/275 no-clean sold by many vendors is almost unusable without added flux.

I have also tried other brands. The best other one is Aim Solder SAC305 with no-clean "Glow-Core" 2.5% flux, and for a water soluble, Aim's WS482 3%.

Alpha's no-clean Telecore Plus SAC305 3.3% is fair, about as good as Aim's Glow-Core.

Basically, the non-Kester 48 is difficult wetting, but works well with added flux. Kester 48 is the best wetting lead-free by far without added flux, but often you still need added flux.

Lead-free just doesn't work like SnPb. Tinning wires for instance, is challenging. Even wetting the entire wire end before soldering, you can never really get the whole thing evenly wetted with solder, without also having to heat it for a minute and have the insulation dripping off. What works best here is just to add flux, then let a bead of solder on the tip of the iron soak into the wire in a few seconds. The strands won't be wetted on their outer surfaces, but will be glued together by the solder that wicked inside.

Actually, SAC305 is somewhat appealing for wire tinning, since lead solder tends to fatigue into mush rather easily when tinned ends are bent a few times, whereas the stronger SAC305 doesn't do this.

As far as soldering PTH parts into a PCB with wire solder, the Kester 48 is by far superior to the others in terms of wetting and flowing. But still not smooth like SnPb.

Use the same as before with a hotter tip.

Graham

PCB soldering is pretty easy, since the holes are already an almost perfect soldering surface. Actually, I was probably soldering to SnPb plated holes, as my proto PCB fab delivers this still. Haven't tried tin only yet.

But I found Kester 48 flowed clear through through-holes, while other fluxes didn't have the ability to "lead" the flowing metal enough to allow the wetting to propagate reliably through holes.

I haven't seen any troubles with cold solder joints, just poor flow.

The SAC305 of course solidifies to a "frosty" finish. This is more so on PCBs, and less so when soldering wires. In fact, oddly much of my wire soldering looks shiny.

It also isn't that difficult to get to soldering temp and flow on PTH PCBs. I use 750F tip temp. One has to be careful about overtemping not only parts, but the flux as well. That is why lead-free often requires solder manufacturers to rework the flux chemistry. Kester 48 is a high activity, higher-temp flux specially designed for lead-free alloys. Both the higher activity is needed, as well as higher temp.

The only place where I have trouble with burning things is tinning wires, like I said.

I haven't tried SMT soldering yet. That is the next phase of experimenting. I am debating whether to continue with 0.015" wire solder to do 0603-2010 range of parts, and ICs, or to try my hand at paste again. Perhaps I will get the 0.015" wire just because I can do it now instead of waiting to get approval and choose new hot-air soldering tools.

I'll comment on my experiences when I get to that. But it may take a few months. I have little need to work with lead-free here now, other than curiosity.

Hello Chris,

What is your experience in terms of results when hand-soldering lead free? What I mean is cold solder joints, burnt parts, general looks. Was it easy to get the hang of it after a few days?

Regards, Joerg

Hello Chris,

Thanks for sharing your experience.

That would be great.

Regards, Joerg

In article , Chris Carlen wrote: [...]

So its "no fluxing good".

I'll have to look into that stuff.

This sounds like Litz wire and lead free can't live together. Does anyone have experience with this combination yet?

Hakko 936 if you need a low price high quality soldering station. Or Metcal 500S if money is no object.

In article , maxfoo wrote: [...]

The Metcal is a nice product. You can solder an 0603 resistor and then solder two pennies together with the same tip. The temperature control happens very near the working point so the regulation is very good.

With the temperature regulation a property of the tips, do you need a different set of tips for lead-free (higher temperature) work?

-frank

The most obvious need is not just the iron, but a "lead free tip" Soldering fluxes are probably more important when using these other solders.

I'm not into lead free, yet

greg .

In article , Frank Miles wrote: [.... metcal ....]

I suspect that the answer is "sort of". The tip temperature is well above the melting point of lead based solder so chances are it would work for lead-free but not quite as well. I'd have to check to see if Metcal has lead-free tips.