Lead-free (halide-free) silver alloys solder

[Elerion]

Hello.
I've been using 60/40 solder for years.
I tried lead-free (halide free), pure tin, with a little bit of copper, and 227ºC.
Even though I use a good quality soldering station, it's hard to work with it. Doesn't flow nearly as well, and the higher temperature required makes my iron tip darker much sooner, so I need to clean and re-tin it very often, which slows down.
I'm thinking about trying a silver alloy, which melts at 217ºC and I heard it flows better.
But I'm wondering what about halides. I'm looking for the least "toxic" solder, for home use, and as far as I know from other topics, hallides are no good. I'm quite sure the flux in the solder is more of a concern than the solder itself.

The question is, does it mater if the core contains hallides, from a technical point of view?

 

[kubeek]

unless you are doing stuff that you are selling in large quantities, I would stick to good old 63/37 tin-lead solder. No need to go lead free as it brings a lot of downsides.

The solder is basically not toxic at all, unless you have a habit of licking the solder joints or putting the solder wire in your mouth all the time.

 

[Elerion]

You inevitably inhale. Sure it is not toxic in the sense of "poison"; it won't kill you. But it is an accumulative process. Lead and flux surely isn't healthy stuff.

 

[Nigel Goodwin]

You inevitably inhale. Sure it is not toxic in the sense of "poison"; it won't kill you. But it is an accumulative process. Lead and flux surely isn't healthy stuff.

There's no health risk from lead/tin solder while soldering it - I was part of a study by the Health & Safety Executive. The actual study was about the effects of the flux NOT the lead - apparently there was a slight risk of the flux fumes triggering asthma attacks in asthma sufferers. The results of the study were that fume extraction was recommended for production workers, but none was required for workers in the service trades.

For home use normal leaded solder is perfectly fine, I wouldn't use anything else (or at work for that matter).

 

[Colin]

Lead has never been a problem. Lead does not vapourise at 300 degrees. The only problem with lead is touching the solder and if you have a holder, you never touch the stuff.
If you want good quality solder you must get eutectic solder. The slight different in percentages of lead and tin makes the solder flow much better than 60/40.

 

[Elerion]

Lead has never been a problem. Lead does not vapourise at 300 degrees.

I understand.
Let's shift to the flux then.
As far as I know, the asthma is related to rosin based flux, not water based.
Anyway, even though it does not cause asthma to most of us, doesn't mean it is good for us in the long term.
I suppose that halide-free flux will, thus, be better for humans.
Agree? Disagree?

 

[Nigel Goodwin]

I understand.
Let's shift to the flux then.
As far as I know, the asthma is related to rosin based flux, not water based.
Anyway, even though it does not cause asthma to most of us, doesn't mean it is good for us in the long term.
I suppose that halide-free flux will, thus, be better for humans.
Agree? Disagree?

Disagree, there's no health hazard with any flux in normal usage, it's only in a production environment where you're soldering 7-8 hours a day every day that it's a slight issue (and only if you're an asthma sufferer). Interestingly my questions to the Health & Safety Executive discovered that they were unable to find a single asthma sufferer in the TV Service trade

Water based flux is rubbish, presumably the 'halide-free' (whatever that might be?) will be even worse - I would recommend proper rosin based flux, that works properly and makes good soldered joints.

 

[JonSea]

I have a spool of "no clean" flux solder. I find the vapors from it extremely irritating. Rosin flux on the other hand is almost pleasant.

 

[hyedenny]

I tried lead-free (halide free)...

Lead-free and halide-free are two COMPLETELY different things. I don't think I've ever seen solder intended for electronics that had any halogens in the flux, and certainly not in the solder.
Rosin is basically tree sap. That doesn't mean it's completely harmless, but it's no more dangerous than burning a log in your fireplace.

 

[hyedenny]

Lead does not vapourise at 300 degrees.

Although your premise is correct, that statement is technically incorrect. Lead (or any substance) has a certain vapor pressure at any temperature above zero K.

 

[kubeek]

Although your premise is correct, that statement is technically incorrect. Lead (or any substance) has a certain vapor pressure at any temperature above zero K.

Yes, but for lead that vapor pressure is so low that the amount that gets in air is miniscule.

 

[hyedenny]

I think I already acknowledged that. ("Although your premise is correct...")

 

[camerart]

Hi,
I have just started making surface mount PCBs, and the last one has probable tracking faults, which is most likely my soldering practice. (I used old unknown solder paste)
I hope to add sensor modules into my projects, one being a barometer pressure sensor. Reading the information sheets, it appears that a lot of care needs to be used when soldering them, e,g, static charge earthing, also soldering temperature, timing and type of solder.
Here are two images from the Data sheet.
Cheers, Camerart.