EEVblog #180 - Soldering Tutorial Part 1 - Tools

[eternal_noob]

Since I'm a cheap ass I make my own liquid flux and desoldering braid.
I found a pack of old and dry Russian rosin chunks on ebay, and dissolved it in  isopropanol. If someone wants to try this, you can get rosin in music stores that sells violins and so on. Ask for a discount on the oldest they have on hand since violinists like them soft. The desoldering braid is simply strands taken out of a piece of speaker cable dipped in the liquid flux and set to dry before use. I apply the flux on the board with the help of a tiny dipstick.
Works like a charm.

[pmrlondon]

If I ever start needing to solder in a "bench" environment again, I will certainly go for a temperature controlled setup. I can see how it's better than a fixed or even coarse-adjustable iron, but many of my soldering situations have been where no convenient 230V AC supply exists - and sometimes no convenient 12V DC either, hence the fact that I currently use a butane iron. The control of that is nowhere near as good, of course.

As for solder composition, I have quite a bit of 60/40, mostly of the "Multicore" brand which is of course excellent - and some lead-free that came from Maplin, awful stuff to use, and all on the thicker side at present. I have found thinner solder gives me better results, as Dave suggests, and will buy some 0.5mm, probably 63/37, before I do any other jobs for which it's essential.

Where I need to use lead-free solder, I now only use it with tips kept for the purpose, as I've found it not to be much good for them.

Cheap solder suckers can be good - but I would recommend keeping two, just in case one jams up - that way, provided it doesn't happen to the other one too, you won't need to stop what you are doing to clean the sucker. (Murphy could easily descend on that, of course.)

For major through-hole rework where lots of ICs are involved, one of my friends used to use a Hot-Vac - not sure what is available in that line these days, and unless you are (like me) into restoring "antique" computers, it might not be a major issue.

[Trigger]

It's been a while since I've seen a well tip.  It seems most of the training and certification courses now are pushing the hoof tips for drag soldering.

The bent conical tips are mainly used to tack SMT parts in place before you drag solder them.

The biggest points for good soldering are a good iron, a clean tip, and liquid flux.  Yes, multicore solder has flux but when my office was sent to get certified to do high reliability work it was stressed to always use liquid flux even with through hole parts to get the best bond possible.

[aXit]

Seems like the only area I'm falling behind is my solder. I think I'll get some multicore then, seems like it's looked very highly upon.

I'm considering the following two:

http://au.element14.com/multicore-solder/3096525-m/solder-wire-60-40-0-5mm-250g/dp/5090787

http://www.ebay.com.au/itm/Multicore-SN63-Hydro-X-015-5lb-Spool-Solder-New-/160587953425?pt=LH_DefaultDomain_0&hash=item2563c9b511

I know dave recommended <0.5mm, but is 0.37mm too small?

[dimlow]

Dave, looks like you solder sucker tip is knackered, Quick tip, stick a bit of silicone tubing over the tip, works great!

[Trigger]

Seems like the only area I'm falling behind is my solder. I think I'll get some multicore then, seems like it's looked very highly upon.

I'm considering the following two:

http://au.element14.com/multicore-solder/3096525-m/solder-wire-60-40-0-5mm-250g/dp/5090787

http://www.ebay.com.au/itm/Multicore-SN63-Hydro-X-015-5lb-Spool-Solder-New-/160587953425?pt=LH_DefaultDomain_0&hash=item2563c9b511

I know dave recommended <0.5mm, but is 0.37mm too small?

Your solder should be between 30% and 50% of the diameter of your component holes for through-hole for control without making yourself feed a ton of solder to make the joint.  It should only take you about three to five seconds for a through-hole joint.  You touch iron to meeting point of the solder and lead to start and then move to the opposite side to fill since solder will move towards the heat source.  It takes some practice to know just how much to feed but you get a feel for it quickly.  I use .020" (0.5mm) for the majority of soldering tasks I have.  0.37mm will work but be ready to feed more for a good joint.  It you're doing SMT then the 0.5mm or 0.37mm will work fine.



This video shows the technique.  It shows lead free but leaded solder makes it easier.

[Bored@Work]

Arg, the dreaded "third hand" board holder  . Don't waste your money on them. They don't hold your board firm, but the alligator clip will scratch and damage your board.

Regarding a hoof or well tip, you can do drag soldering with a simple chisel tip, too. It takes a little bit of practice and you have to pay more attention.

[ejeffrey]

I really like using a small vise with plastic jaws and a rotating ball mount as a board holder, primarily for through hole components.  You can hold small boards clamped lengthwise between the jaws, while large boards can be clamped on the edge.  You can hold the board horizontally while leaving the bottom side clear so the leads don't press into the desk, or you can hold them vertically so you can solder the bottom side of the leads without the component falling out.

Surface mount components can easily be soldered with the board lying flat, although I still put small boards in the vice just to keep them from moving around. 

[saturation]

Third hands aren't bad, its like having an army of munchkins holding things.  If you need a vise, get a vise.  I use the 3rd hand to hold wires while soldering, and their metal hands take heat very well; Panavise are far more costly and its all plastic construction is a bit more frail that the steel hands.  The hands also act as heat sinks when soldering items, pulling heat away if you need them.  You can use them to hold items while you blast them to heat shrink tube them and not worry about heat; you can put them inside a DUT, to hold things for you.

If you do get one, spend the extra $1 to get the better made clone with arms that are thumb screwed versus snap on.  There are so many copies, the bad ones are much worse.

Cheap clone on the left, note the alligator is just snap on, versus held with thumb screws on the right.  The hand on the right is 20+ years old, cost about $7, the one on the left is newly made clone, about $3.  Note the diameter of the shaft and thicknesses of the metal, the clone is about 1/3rd thinner.



If you worry about the alligators scratching or biting things, just insert a guard, a penny or washer between teeth to provide a flat surface, or insert a folded U shaped sheet of thin rubber.

[saturation]

Never thought of making my own solder wick, but that's a good idea, thanks.  I can get scrap braided wire and dip it rosin and see what happens.  Better than just dumping it, recycle, reuse!

Since I'm a cheap ass I make my own liquid flux and desoldering braid.
I found a pack of old and dry Russian rosin chunks on ebay, and dissolved it in  isopropanol. If someone wants to try this, you can get rosin in music stores that sells violins and so on. Ask for a discount on the oldest they have on hand since violinists like them soft. The desoldering braid is simply strands taken out of a piece of speaker cable dipped in the liquid flux and set to dry before use. I apply the flux on the board with the help of a tiny dipstick.
Works like a charm.

[EEVblog]

Better than just dumping it, recycle, reuse!

Used solder wick makes excellent high current wire!

Dave.

[vtl]

Good video, look forward to the followup. Soldering is certainly one of my favourite aspect of electronics.

I think theres not many good videos out there on soldering, its certainly a hard topic to cover properly. Theres quite a lot to know from gear, technique and knowing the characteristics of solder. Most instructional videos simply show you how to solder some dip chip into a perf board or something. Thats generally useless and anyone can do that really.

You said its hard to do bad soldering but I've certainly found most of the people at my uni absolutely suck at it, even with proper soldering stations. What people really need to learn is how the solder actually works and know what to do when something goes wrong. I reckon you really need to know how solder works otherwise you'll be sitting there wondering why the solder wont stick to the joint. Time and time again I've seen people are doing shit joints because they've burnt off all the flux and they end up with a huge blob on the board, wondering why it wont work.

[sacherjj]

I have one of the third hand devices and it is crap.  I use one of these Panavises: http://www.amazon.com/gp/product/B000JC7FM0

Works great on small to large boards.  Legs up from the third hands.  Just did my first SMD soldering with it last night.  Worked great.

[mikeselectricstuff]

Seems like the only area I'm falling behind is my solder. I think I'll get some multicore then, seems like it's looked very highly upon.

Multicore is just a sales gimmick from the company of the same name.
May be noticeable on large wire diameters, but at the sort of sizes used in electronics there is no difference between single and multi cored solder.
Just so long as it does have a flux core. You rarely see non cored electronics (as opposed to plumbing) solder - I've only ever seen it in Russia.

On the subject of holding boards down, a lump of blu tak is often very effective

[Mercator]

Hi,
I don't get why Dave hates those soldering irons that have a direct connection to the mains. I'm not an electronics professional (mechanical engineering student) and I only use through hole parts, but for years I used the cheapest solder (1mm) and an Ersa soldering iron with a direct connection to the mains and I never had any problems with it! And if so, I used a solder sucker and did it again. No problem.

Don't get me wrong: I'm sure a soldering station and expensive super thin multicore solder make great joints, but the cheap stuff works as well.

Oh, by the way: My soldering iron has a conical tip!

[dengorius]

Hi,
I don't get why Dave hates those soldering irons that have a direct connection to the mains. I'm not an electronics professional (mechanical engineering student) and I only use through hole parts, but for years I used the cheapest solder (1mm) and an Ersa soldering iron with a direct connection to the mains and I never had any problems with it! And if so, I used a solder sucker and did it again. No problem.

Don't get me wrong: I'm sure a soldering station and expensive super thin multicore solder make great joints, but the cheap stuff works as well.

Oh, by the way: My soldering iron has a conical tip!

Because they're basically firesticks. While they're ok for soldering some PTH components, they're not very good for fine pitched SMD or temperature sensitive parts. Beside that, most of the time the tips and heating elements are made of low quality materials and worn out pretty quickly.

Without a good quality, temperature regulated soldering iron is much easier to get cold joints, damage parts or even scorch the board.

[Neilm]

There is nothing wrong with the conical tip that is supplied with a soldering iron. I have been quite happy to use one. I needed to widen a hole in a plastic box and it was EXACTLY the correct size.

Neil

[Vertigo]

i get the impression that Dave feels that being limited to only trough hole components
is not going to be an option for much longer even for hobbyists.

[nukie]

In regards to solder wire size, once you go down to 0.3mm size you will find that there's very little flux inside them you will have to work quickly before they oxidize under heat. In most cases extra flux helps. I find that 0.5mm is a bit thick for SMT soldering but it contains adequate flux.

In my experience, 0.2mm conical tips is best for SMT, get the short ones, not long ones. Short tips has faster thermal recovery than long tips that's why some people have problem with thermal transfer. If you add flux to your soldering area I don't see why heat don't move around. Flux is a good thermal conductor. I do about 2500 SMT solder joints per week, mostly SOT, 0603, 0805 sizes.

I like the higher end hakko FX-951 which has the tip and temperature sensor coupled tightly like wise for JBC irons. The thermal recovery is much better on these tips. I like how Antex implement their sleeve tips, there's a leaf spring in it that secures the tip to the heating element. It's a tight fit means good heat transfer.

For the Hakko 93x/888 units, I recommend copper shims from K&S metals of 0.002 or 0.003" thickness wrapped around the heating element before inserting the tips. I used this trick for many years it seems to work well. If you look carefully, there's iron shim in the original tip, if you can remove it, then replace it with a thicker shim it will be best. When fitting a shim make sure it's not too tight so there's room for the heating element to expand.

[Big Gaz]

Hi All,

I found Dave's SMD work very enlightening. I have always avoided SMD's and if challenged I used the finest tip I could find and applied solder pin by pin.

I'm in the market for a new soldering iron and after Dave's recommendation I have been looking at the FX888. We only have one stockiest here in the UK.

Can anyone provide the Hakko model/part number for the concave tip Dave was using for the sweep motion SMD work

Regards

Garry

[FreeThinker]

If you don't use a lot of solder buy the small reel size (about the size of a half roll of electrical tape). I've found that solder can oxidise on the top layer if left untouched for a few months and it can make solder flow difficult. We used to buy 500grm
spools and it could sit  in the cupboard for years before being used up. Another tip is to get an old 35mm film container, wrap solder around the outside like a spring, pop it inside the container and put a small hole in the lid. Pass one free end through the hole and pop on the lid. This helps to keep the solder clean and free from sweat from the hands. You are also not holding the solder and absorbing lead.

[sacherjj]

If you don't use a lot of solder buy the small reel size (about the size of a half roll of electrical tape). I've found that solder can oxidise on the top layer if left untouched for a few months and it can make solder flow difficult. We used to buy 500grm
spools and it could sit  in the cupboard for years before being used up. Another tip is to get an old 35mm film container, wrap solder around the outside like a spring, pop it inside the container and put a small hole in the lid. Pass one free end through the hole and pop on the lid. This helps to keep the solder clean and free from sweat from the hands. You are also not holding the solder and absorbing lead.

I've been using some small solder that I acquired 26 years ago.  It flows fine.  I've used about 1/2 pound of the 1 pound roll.  Good quality solder and flux make this not a problem. 

[FreeThinker]

I've been using some small solder that I acquired 26 years ago.  It flows fine.  I've used about 1/2 pound of the 1 pound roll.  Good quality solder and flux make this not a problem.

This is true flux will cause the oxide and other crap to pool on the surface. However this is part of the problem as the small pitch (and lack of leads in some cases)  of smd devices can cause solder bridges due to this oxidation residue not allowing it to wick correctly.It's not a major problem but one that can catch out the novice and can be very difficult to correct if it gets under the device. If you have a large stock of old solder then by all means use it, but if you are buying new, don't bulk buy if you are a low volume user, unless you have a good reason.

[pmrlondon]

Another tip is to get an old 35mm film container, wrap solder around the outside like a spring, pop it inside the container and put a small hole in the lid. Pass one free end through the hole and pop on the lid. This helps to keep the solder clean and free from sweat from the hands. You are also not holding the solder and absorbing lead.

Ah, a DIY dispenser.

The Multicore brand solder I have came in dispensers - one a metal one that may well date from the 1970s, the other a plastic one from 1988 or so. The lead-free Maplin solder is also in a much smaller plastic dispenser. I agree, avoiding handling the solder directly is a good idea, on all the points mentioned.

[FreeThinker]

Another tip is to get an old 35mm film container, wrap solder around the outside like a spring, pop it inside the container and put a small hole in the lid. Pass one free end through the hole and pop on the lid. This helps to keep the solder clean and free from sweat from the hands. You are also not holding the solder and absorbing lead.

Ah, a DIY dispenser.

The Multicore brand solder I have came in dispensers - one a metal one that may well date from the 1970s, the other a plastic one from 1988 or so. The lead-free Maplin solder is also in a much smaller plastic dispenser. I agree, avoiding handling the solder directly is a good idea, on all the points mentioned.

Yep the old multicore 'Steradent' tubes were great but sadly no longer availing AFAIK. But a diy version is just as good One enhancement is to pass the solder through a narrow bore tube first, supposed to help prevent snagging.