How To Solder: Copper Pills,LEDS,Drivers,+ Equipment and Supplies

Hi everyone,

Here is what you can expect from the video.

1. Basic "how to" soldering skills
2. Best practices to avoid pitfalls and brittle joints
3. Tips and tricks on how to get stubborn parts like copper pills to solder
4. Equipment and soldering supplies I recommend.



If you have any helpful hints of your own please feel free to share

This works in the US where tin/lead solder is still common, but in much of the world, lead free solder is what they use and others can be hard to find.

- Brass pads work great for tin/lead, but not for lead free solders and their typical fluxes. You need the water/sponge to properly clean the iron tip (and prevent oxidation).
- I personally would not go with anything less than 40W
- The iron you reference is good, but it's 50W and temp controlled, not variable power
- The temp you are using for tin/lead and likely rosin flux is way too high. That's a fast path to oxidized tips and higher potential for damage of small parts. Something more in the 740 range would be better.

Some of the Chinese made irons are half decent and are compatible with Hakko tips. You can find the low end REAL Hakko irons for the same price as the Weller and get name brand tips at a reasonable price and no-name tips for next to nothing.

If you are going lead free, pay the extra money for the solder with silver in it. It flows much better and for the little you will use for flashlights, the cost is well worth it. Be careful with the lead free fluxes. Stick to no-clean unless you plan to clean your boards

I didn't know that brass wool doesn't work with lead free. The folks on our production floor have all switched recently to brass wool from wet sponges, and they use lead free about 95% of the time, with either water soluble or no-clean flux as called for (more WS than NC, but not by a huge margin). I haven't tried brass wool yet, but I guess I'll have to try it soon. If it's not as good, I'll have to berate them for liking an inferior product ;-).

At work we use SAC305, which is SnAgCu, 3.0% Ag, 0.5%Cu, balance Sn. In my own work, I've found that I prefer Sn100C. It produces a nicer finish and I think it wets better. I don't know the exact composition, but it is NOT pure tin. The tiny amounts of additives (which are patented, but I don't think secret) make Sn100C very different from Sn100. Having worked a fair amount with both SAC305 and Sn100C, I'd definitely recommend paying the small premium for Sn100C. I pay more for royalties than for silver, but I don't care. The cost is trivial in the long run.

Of course I would prefer to use 63/37 (it isn't an accident that it's been the most popular alloy for generations), but I ship a lot of stuff out of the US, so I use lead-free for everything, rather than risk cross-contamination. I keep the 63/37 around for personal projects because it's so much nicer to use, but I have a separate iron, sponge, etc, just like we do at work. It's all been in storage for quite a while now.

I have a roll of 0.032", which is great for tinning and for larger joints. For really fine work I have a roll of 0.010" which I love. Most modders won't need it, but if you assemble boards with fine-pitch parts, I highly recommend it.

One thing that hasn't been mentioned so far is that it is really important to keep your tips tinned (coated in solder). This keeps the tips working at optimum performance. When the tip is coated in solder the solder oxidizes, and this is okay because it gets wiped off. When the tip is exposed, the tip oxidizes, and this is bad. Strangely, it seems to be most important when you turn the iron off. I always tin the tip before turning it off, and frequently check a few minutes later to make sure I didn't forget (I'm not as young as I used to be).

Nobody over-emphasizes the importance of flux. It would be hard to do, as flux is really important. Without flux it would be nearly impossible to make good joints by soldering or brazing. In big joints - tinning wires, boards to pills, etc, the flux that's in the solder is often enough (assuming you are using flux-core solder, which almost everyone does). But in small joints (like 0.010" wide pins on 0.019" spacing) it really helps to have liquid flux applied prior to soldering. =

Another great tutorial Matt! You covered most of the important stuff quite well and you know what they about a picture. You didn't waste a bunch of time with associated tip's that could have made your video long and drawn out. It's important to not over simplify or get bogged down with technicalities. Tough to balance things out.

I would recommend to all of the viewers who wish to do this type of work, but have not received any certified or schooled training, ensure they understand some of the inherent dangers associated with exposure to soldering. Remember your liquefying metal. Don't hover directly over your work for prolonged periods breathing the fumes. Wear eye protection for not just burn protection but your epidermis as well. Known as MCS for some it can create some serious health issues. Lastly I would recommend you wear surgical gloves when using any liquid or paste flux. Chemical burns are something to take into consideration as direct contact contamination which can be ingested or placed where they will harm you like if rubbing your eyes or touching your face. Lord knows that one has gotten me several times over the decades when in a hurry to complete work.

One thing I would like to recommend to the lessons being demonstrated here is to always clean your work after completion. Make it free from flux residue. Not hard to do. Buy a big pack of Q-tips and some 90% iso alcohol (or your favorite solvent) and ensure its all tack free or shiny clean. Nothing worse than swapping out a drop in 6 months down the road and wonder why its sticky?

Take your time. Have a plan. Stick with good work habits. Don't succumb to short cut's.

+1 on cleaning. Usually this is purely cosmetic, but the flux I use is really sticky and makes things unpleasant to handle. Comes off with IPA, but I've recently switched to denatured alcohol (bought in the home center paint department). It has no water at all, so dries really fast, and it dissolves the flux faster too.

But note some fluxes MUST be cleaned, as they are either conductive or continue to be active on the board, eroding the copper. I've seen more than one board destroyed by highly active flux that wasn't cleaned properly after somebody worked on it.

Cleaning also makes it easier to see defects in the soldering.

Those active fluxes are the ones that don't work well with brass sponges and leave your tips damaged. Even no clean fluxes have some activity.

Alcohol does not work for all fluxes. Some modern fluxes require a proper cleaner ... And some are best cleaned with DI water.

I would recommend a short bristle brush over a q-tip and always always rinse with lots of flux remover. With modern no clean fluxes poor cleaning can be worse than no cleaning. Poor cleaning can just release conductive residue and allow it to wick under fine pitch and other SMT parts causing the circuit to fail.

+1 on cleaning. I use an dent alch wash, then a di water scrub followed by another fresh alch rinse and dried compressed air to blow dry. Flux residue, wether rma, nc or rosin, should be cleaned off in any situation, especially in anything sealed with optics. Non rosin fluxes (including no clean liq) can damage boards over a fairly short period of time.

Thank you everyone for your input, its much appreciated!

My personal best cleaner for the flux is actually Goof Off. Instantly devolves even the residue from the tacky flux. Just make sure you do NOT touch the LED dome with. This will cause it to cloud and crack.

Huh. Goof-Off never would have occurred to me. I'd worry that it might damage other parts too, especially markings. I know it strips paint pretty well. How much experience do you have with it on electronics?

I think the worst thing to clean is when someone fails to clean one flux off before using an incompatible one. Some combinations (rosin flux-core and no-clean liquid, at least the ones we use) create a black crust that's especially hard to remove, while others create white films or crust, especially between fine-pitch IC leads. I'll have to try Goof-Off next time I encounter one of these. It might be a while, though, as most of us are pretty careful to 'always clean between'.

DIW, hence the 3 stage wash that I do... Covers all bases. My wife and I have been in the electronics industry for many years now and short of having an electronics wash system, the said 3 stage wash is best for ALL the issues you've stated.... Please don't use goofoff on electronics without tons to waste.
Adding: dry compressed air is a major plus in drying washed populated boards, beit smd OR thruhole.

DIWdiver said:

Huh. Goof-Off never would have occurred to me. I'd worry that it might damage other parts too, especially markings. I know it strips paint pretty well. How much experience do you have with it on electronics?

I think the worst thing to clean is when someone fails to clean one flux off before using an incompatible one. Some combinations (rosin flux-core and no-clean liquid, at least the ones we use) create a black crust that's especially hard to remove, while others create white films or crust, especially between fine-pitch IC leads. I'll have to try Goof-Off next time I encounter one of these. It might be a while, though, as most of us are pretty careful to 'always clean between'.

Click to expand...

I've been using the goof off for a year or so. I've never had it remove any markings (other than ink pen ones). The only component I have had it damage that I know of is the dome of an LED, but I basically work with the same parts all the time.

What are thoughts on using acetone? I already have some for other projects so that's what I use.

:::sigh:::

So I guess I should just buy some alcohol then. I looked at the denatured while at Walmart earlier, it's also in the paint section.

light-modder said:

So I guess I should just buy some alcohol then. I looked at the denatured while at Walmart earlier, it's also in the paint section.

Click to expand...

Please do. Your electronics will thank you.