Anyone else using lead free solder?

So, all the RoHS labels on my parts got me thinking, do I really need to use solder with lead? I tried a sample of some lead free stuff. So far it's pretty good, some small whiskers occasionally, but it looks nice. You need to set your iron a little hotter - my cheap butane iron is doing it without too much trouble, even the bigger diodes, but I have no idea at what temperature the tip is running at.

Anyone else using lead free solder? Any tips or ideas?

Wade

You need higher temps, the flux in it gives off worse toxic fumes so you need extraction and it is harder to make good joints and they always look like dry joints. It will probably grow tin whiskers over time causing everything to short out.

I stick to leaded at home unless I am repairing something that is lead free. It is not good to mix.

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[www.hydraraptor.blogspot.com]

I've been using it for a couple of years, nothing religious just the last spool I bought was lead free and I've still not got through it.

My random observations/thoughts are:

Lead free solder doesn't correspond to one alloy. A quick look at wikipedia gives 15 common alloys, compared to the two common, and very similar, lead alloys. I'm using Sn/Cu0.7 which was cheep but has the highest melting point out of the lead free solders.

For hand soldering: I had to get a better iron to get good results with it, my old one wasn't temp controlled and I don't think it was hot enough. My new one is temp controlled and 48W, 375C works but I tend to use 400C to avoid heating the leads of a component for too long. At such high temperatures I worry about the tip wearing quickly but it still looks fine after about 100 hours over 2 years.

Flux: the flux in my stuff doesn't do much, the components either have to be carefully cleaned before or extra flux added to the surface. I can't tell what flux is in my solder though so this doesn't necessarily mean anything about the fluxes used in other people's solders.

For long term durability; I have things I soldered two years ago that are still working fine. I doubt there is much knowledge though about how it fares over decades as few manufactures would want it to work that long.

Tin whiskers: Not that I've noticed, but they can be very small and may take up to a number of years to start appearing. A good site on it is [nepp.nasa.gov] although what it mostly explains is how many unknowns there are.

Overall, little reason to avoid it, little reason to use it.

Matching the existing solder when carrying out repairs is probably the strongest deciding factor in selection.

Pete

P.S. despite practice, reading and equipment I am still far from 'good' at soldering. I've reached the level where I don't burn tracks up from the board but I'm slow and it's clear from arms length my soldering / repair compared to the rest of the board. None of this is likely to be the solders fault though ;-}>

Interesting! My reason for switching to lead free was to minimize my toxic exposure, but it sounds like the flux is worse. Not good, as I don't have any sort of fume extraction yet, other than an open window. Maybe I'll make a little exhaust fan pipe combo to suck the fumes out the window.

I'm used to hand soldering surface mount parts, very fine pitch, and I had no trouble at all using the lead free solder. I haven't done this much soldering in a few years, but it went well, although I did notice my iron tip wore down noticeably over the course of 3 stepper driver boards. Probably the lack of temperature control on my cheapo iron, and the higher tin content of the solder.

Tin whiskers I don't know about. They sound like trouble down the road, I'll have to keep an eye out and check the type of solder I have to see if it's susceptible.

Funny thing is, I think I'm faster at surface mount soldering. I found all the wire insertion, bending, and clipping a bit tedious - I'm used to soldering up piles of 0804 resistors in a row with tweezers, bang bang bang. One of my co-workers was great at tomb stoning surface mount parts up into intricate shapes on prototype boards, we called it Theo's 3d House of Circuits.