electronic soldering

Can you solder effectively? When I try, it sometimes comes out all right, but sometimes rather sloppy, as the hot ball of solder is often too big before it will leave the iron.

What exact solder type do you use? Diameter? What about flux? Size of soldering tip? How much does a decent, fixed temp iron cost and where to best buy one? How do you prepare that soldering tip?

When you are dealing with tiny components these matters become serious. Thank you. - David Lyga

There is a type of electrically conductive epoxy glue for heat sensitive applications and for the soldering-challenged.

Interesting: brand name and will this conduct electricity? - David Lyga

I use a fine tip Weller iron rated 35Wats. The solder is 24WG fine ressin core meant to be used for electronics.

After heating the iron n applying fresh solder to it, wipe it clean just before making your joint. If you are doing wires.. pre tin everything before making the joint. Put your pieces together, clean the tip again.. now just toutch the pieces with the iron to heat them and feed the solder till you have a nice looking joint. Dont toutch teh tip of the iron with the solder.

If you are doing a PC board... set up your part to be soldered on its trace or pad... clen the tip of the iron, toutch it to the part at the pad or trace n feed in the solder..

easy enough. Try looking it up on you tube so you actually see it done. Sounds harder than it is.

Max Bond is one company's name that makes this. Conducting electricity is its intended purpose.

Soldering is a good skill, you just need to develop the right technique, practice, practice, practice!

Or just use silver epoxy.

I use a Weller professional soldering station that I bought from ebay used, but it's probably overkill.
Adafruit sells reasonably priced irons and tools, their site also has some good tutorials and how-to guides.
https://www.adafruit.com/categories/84

Thanks all, I think that this thread will be of great benefit to many. - David Lyga

Personally I find silver epoxy to be far harder to use in the long run than proper soldering. The few times I've had to deal with gear that has been previously repaired with it I've found it to be more of a hinderance. We couldn't desolder it normally, and in one case it wicked oddly across a board and left small, nearly invisible, traces that caused us headaches.

It doesn't take long to learn to use good fine gauge lead solder on electronics, but it does take practice. Paying the little extra for a cheap hobby soldering station, rather than just a basic soldering iron, can really make things easier in the long run. Also picking up a few LED kits or something to practice with before jumping into trying to fix a camera is probably a good idea.

Key things to remember when soldering:
1. Clean work space - This includes not only the workbench you setup, but also keeping the tools and stuff you're working with clean. You can't solder onto corroded parts and expect it to work well after all. So take a few extra minutes and prep things before working with them.
2. The soldering Iron does NOT melt the solder! A point which seems really weird when you start, but usually learn quickly enough. The parts you are soldering are what needs to melt the solder. The iron is just used to bring those parts up to temperature.
3. Heat management is key. - Care and attention needs to be taken. Big chunky parts need more energy to bring them up to temp, but too much heat will kill some parts. If you're not familiar with something then best to spend some time on google for user comments on them. I've ruined more than a few random things over the years because I misjudged temperatures.
4. Spend time on youtube looking at GOOD soldering, and people who highlight good vs bad. It becomes easy to spot quickly enough.
5. Get a good multi-meter, and learn to use it. (Re-soldering a broken contact doesn't help you if the chip it is connected to is dead anyway.)

You should never have a big blob of solder on the tip, just clean and tinned with enough to help the new solder flow when it's applied. My little sponge is the messiest part of the rig when I'm done with something.

Properly prepare the parts, like Luckless said, you can't expect solder to flow onto grungy surfaces.

I have to say it, use leaded solder. The non-lead varieties only work in a restricted temperature range and your technique and gear will have to be above average. And that non-lead stuff looks like a corroded mess even when it's applied perfectly

Long ago I used Weller soldering irons if nothing else was available, but much prefer Ungar soldering irons with an appropriate tip.

luckless is exactly right. Find a good flux pen too. They are like a marker that you can pencil some flux right on the joint area. They make both rosin and no clean flux varieties. Place like Mouser and Digikey have these items mail order.

The right size tip is important too. a fine point tip will just not transfer enough heat for bigger parts. And obviously, a giant tip is hard to direct heat onto smaller parts. A good, adjustable iron is handy, you should turn it up to just hot enough to do the job.. avoid turning it all the way up, it just ruins the tip, and can damage the components. If you have to turn the heat up to get it to melt solder, then your tip is probably too small.

And leaded solder is much easier to get to flow for the hobbiest. Good luck

My tips here apply to hobby/prototyping and not to production work, and not to surface mount.

I usually switch the iron to high power setting ( eg 30W) before doing a joint, even for ic pins.
That is because a quick application of a hot iron will do a better joint and have less heat running down to the component that a slow joint with a cold iron.

Always examine the new joints with a magnifier, looking for fusion to the pin and no runs over to another pad.
A few minutes here can save big dramas and time wasting at power up time.

When replacing an ic, or header etc, first cut all the pins off with the nippers, then re-tin the pads, then just suck the remaining pin out of the pad.

Use IC sockets where possible.

For development or hobby work I do not wrap the wire around the terminal ( contrary to production procedure). Just make J hooks and fuse around the terminal.
This allows more reliable de/resoldering with less insulation damage if a change is to be made.

Do not strip mod wire or enamelled copper wire. Instead, use the iron tip aganst a paper pad to melt off the insulation. This is to avoid nicks in the copper wire which can break at edge of the joint.

When the iron is sitting in its holder set it to low ( eg 15 W ) to preserve tip life.

To get the tip hottest for a bigger joint, hold the iron vertically so the hot air shrouds the tip, before doing the joint.

Before desoldering using a solder wick or solder sucker, always remelt the joint first with a soldering iron and apply some new solder (mainly for the flux).

When the tip gets eroded, I file it back to a new tip with a flat then re-tin.

I have a life time supply of the old 60/40 resin core, but for my son's projects I use lead free. It seems to work just as well.

Oh.. and my soldering improved greatly after the new lens implants !

+1 all the advice to use lead solder. For small work, you allude to, i use .031 44% resin core Pb solder. Soldering iron is important also as many point out. You need a temperature controlled solder iron. For Pb, 700F is about right. The temp may be why you have a ball of solder at the end of the tip. I use a temp controlled tip rather than the temperature controller box, it is not important just a personal preference.

@bdial link to soldering equipment and how-tos looked nice. the temp controlled iron they had looked good and is a lot less expensive than my weller. If tips are readily available then it might be a good choice.

@Luckless had great notes.
Use the wet sponge every time the iron is withdrawn from the work, and just before tinning the tip. keep sponge wet.
Except for being tinned, solder should not be globbed on tip when put to the work. The iron is not for applying solder, but just for heating the joint.
Also before tinning the tip but after cleaning with wet sponge, i dip tip of iron in a little resin paste.
Heat both metal parts (wire, pads) just enough that the solder will flow - first. Do not apply heat for too long. Only then, feed just enough solder to the joint (not trying to feed the iron) as the solder melts. Not very much will be required. It should flow well and mold to the work being soldered. remove solder feed and heat. Joint really should have a shiny surface when it cools down.
Heat sinks when they can be applied between leads and component case will save destruction of the component.

Great tips! Thanks for posting this!

Use a soldering iron size, wattage and tip, according to what you are soldering. I use a 15 watt iron when soldering IC chips. Never use a soldering gun on solid state devices, diodes, transistors, IC's. The AC current is applied to a heating element in a iron and direct to the tip on a gun. The direct application of AC can/will damage the solid state materials.
Use only rosin core solder for electronics.
As others have said keep the tip clean and tinned.
Place the tip next to the item to be soldered insuring it makes good contact with the item. Touch the solder to the side opposite the iron. Flow only enough solder onto the joint to make good contact. Remove the solder then the soldering iron.
Do not move the joint until it cools on its own.
I have spent many an hour soldering IC chips with a 15 watt iron and a 5X magnifier lamp to see the chip pins.

luckless tip #2 is where my students usually fail. Don't be afraid of the heat, just apply it decisively then solder onto that. Easy and quick when you get the hang of it. Lead solder is easiest but don't mix with more modern solders, clean all and then go lead

Buy high quality irons of suitable size and wattage for the jobs you need done. Buy appropriate tips for those irons. Keep the tips clean as you solder. Heat the connection, not the solder, and let the connection melt the solder (don't touch the solder to the iron). Don't overheat delicate components. Other than that, any decent solder with flux center works fine but use thin solder for tiny jobs and thicker solder for big jobs.

Once I asked my dad if he had solder, and he gave me some. I could not get it to flow right, and it had to be too for the electronics I was working on. It turned out to be tin/antimony solder - for plumbing. Definitely use lead solder, with a flux core if possible.

I'm not sure what you are soldering, but typically you heat the material with the iron and then touch the solder to the joint - is should melt and flow in.
Someone once taught me to solder to circuit boards - he would actually tin the trace and the wire before soldering them together.

Heat the joint in the circuit that you want to solder and then bring the solder to the joint, not the solder iron. The heat will melt the solder. Silver solder is for jewelry; acid core solder is for plumbing; resin core solder is for circuits, unless the equipment is for space flight which means that you cannot use solder with tin since that would form tin whiskers in zero gravity.

Thank you all. What I learned that is most important here is this: 1) use the correct size of soldering wire: I use .06 and you say to use half that size. 2) do not melt the solder by touching it to the iron (unless tinning the iron), and 3) use a narrow tip on the iron.

I appreciate all this and you have also helped others as well. - David Lyga

Yes, David, and keep the solder tip CLEAN. A damp (not wet) sponge works well.

Yes the sponge is very impotant and damp not wet but keep it moist (i may have said wet earlier, ONF cleared up on damp).

The type of solder and flux are the most important factors. Some solder is poor due to regulations for the cellphone/trash industry that presume what which you are soldering will be put in the trash dump.

I use the Hakko soldering work station and fine tips. I teach the students to apply heat on the wire and apply the solder to opposite side and not directly to the soldering tip. I agree with making sure the iron is hot enough so a minimal of time is applied to the joint. The appearance I look for is a shiney sheen and shaped like a Hershey kiss with the copper pc pad being covered. The best little thing item for cleaning off excess solder is the ball of brass shavings you can buy nowadays. The newer Hakko workstation us it to clean the tips with. I used to use the wet sponge but have now switched over to the brass shavings. As for solder, lots about. Just use the ones designed for circuit board work (really small 24 or 28 gauge) with a 5 resin core. Preferably lead free.