When you’re just learning to sketch, you use graphite. Why? It’s cheap, great at training you to recognize different shades, and most of all, it’s erasable. When you’re learning, you’re going to make mistakes, and un-making them is an important part of the game. Same goes for electronics, of course, so when you’re teaching someone to solder, don’t neglect teaching them to desolder
We could argue all day about the best ways of pressing the molten-metal undo button, but the truth is that it’s horses for courses. I’ve had really good luck with solder braid and maybe a little heat gun to pull up reluctant SOIC surface-mount chips, but nothing beats a solder sucker for clearing out a few through-holes. (I haven’t tried the questionable, but time-tested practice of blasting the joint with compressed air.)
For bulk part removal, all you really have to do is heat the board up, and there’s plenty of ways to do that, ranging from fancy to foolish. Low-temperature alloys help out in really tough cases. And for removing rows of pinheaders, it can help to add more solder along the row until it’s one molten blob, and then tap the PCB and watch the part — and hot liquid metal! — just drop out.
Trying to solder an oddly shaped art PCB board? This 3D printed visa could help:
A regular vice is great if you want to clamp rectangular objects, but it can fall down a little with more complex shapes. Inspired by an ancient vise [Chris Borge] whipped up his own 3D-printed fractal clamping tool.
The inspiration for this one comes from the [Hand Tool Rescue] video that shows of the clever mechanism. The vice uses a series of interlocking parts that can freely articulate to grip the object of interest via several protruding fingers. In reproducing the design, [Chris] had some issues initially with the joints, but settling on a dovetail similar to that of the original metal vice which got things working nicely.
If you want to build cool things these days, you’ve probably had to master surface mount electronics. However, for many people, ball grid array (BGA) is still intimidating. Have a look at [VoltLog’s] video about his techniques for soldering BGA and inspecting that you managed to do it right.
He’s got quite a few tips about things like surface finish and flux selection. It looks easy when he does it. Of course, having a good PCB with good registration markings will help too.
You can’t get a soldering iron under the part, of course. A hot plate provides heat from underneath. A gentle push from a hot air gun will push the solder balls over the melting edge. Even taking the part off the hotplate requires a special technique.
Without seeing the result, how can you know if it was successful? Pros can use an X-ray machine, but you probably don’t have one of those sitting in your shop. [VoltLog] uses a DVM and tests the internal protection diodes that the chip almost certainly has on its pins. However, to do that, you need to put the chip on a bare board. If you were repairing an existing board, the technique wouldn’t be useful since other components on the board would throw the measurements off.
From Ken Olsen of Maker’s Box on Tindie:
Show off your Doctor Who cred with a DIY badge you can solder yourself. Powered by an Attiny85, lights and sounds like an 8-bit TARDIS. CR2032 Battery not included.
- 1 ea., Perfect Purple PCB from OSH Park,
- 1 ea., Pre-programmed Attiny85, Atmel ATTINY85V-10PU
- 1 ea., SPDT Switch C&K JS202011AQN
- 1 ea., White diffuse 5mm LED, Lumex SSL-LX5093UWW
- 1 ea., 100 ohm 1/6W 5% Resistor, Yageo CFR-12JB-52-100R
- 1 ea., Piezo speaker, TDK PS1240P02CT3
- 1 ea., CAP CER 0.1UF Vishay BC1160CT-ND
- 1 ea., SMD Battery holder, Linx BAT-HLD-001
From Al Williams on the Hackaday blog:
Oregon State University must be a pretty good place to go to school if you want to hack on robots. Their robotics club, which looks active and impressive, has a multi-part video series on how to solder surface mount components that is worth watching. [Anthony] is the team lead for their Mars Rover team and he does the job with some pretty standard-looking tools.
The soldering station in use is a sub-$100 Aoyue with both a regular iron and hot air. There’s also a cheap USB microscope that looks like it has a screen, but is covered in blue tape to hold it to an optical microscope. So no exotic tools that you’d need a university affiliation to match.
Even if you’ve done a lot of SMD soldering, you can always pick up new tips and tricks. There’s lots of flux, of course, and careful alignment before you secure the component down. We know the feeling of leaving a bad solder joint long enough to go secure the other pads and then cleaning it up at the end.
NOTE: make sure to check “After Dark” in the cart
The MakersBox has a great kit for beginners on Tindie:
The perfect night-light, and a great way to learn how to solder.
The Joule Thief is a clever little circuit that can light a LED with a battery that is nearly dead. It does this with a pair of opposing magnetic fields. I like this circuit because it is simple to build, yet demonstrates some very complex electrical behavior.
I’ve designed a printed circuit board to help make this easier to build for beginning Makers. I used open source KiCAD software to lay it out (a future Instructable?), and OSHPark to manufacture it. If you want to just wire one up without the board, check out Angelo’s Instructable which uses essentially the same circuit.
The kit contains:
- 1 – PCB, https://oshpark.com/shared_projects/rLeF8F88
- 2 – AA Battery Clip, Keystone Electronics #92
- 1 – Ferrite Tubular Bead, Digi-Key 240-2301-ND or similar
- 1 – SPDT slide switch, E-Switch EG1218
- 1 – 1K resistor 1/8 – 1/4 W
- 1 – PN2222 Resistor, Fairchild Semiconductor PN2222ATA
- 2 nanoseconds (about 24″) of insulated wire. Two different colors are helpful.
- 1 – LED, 10mm white (or use your own)
Soldering irons are a personal tool. Some folks need them on the cool side, and some like it hot. Getting it right takes some practice and experience, but when you find a tip and temp that works, you stick with it. [Riccardo Pittini] landed somewhere in the middle with his open-source soldering station, Soldering RT1. When you start it up, it asks what temperature you want, and it heats up. Easy-peasy. When you are ready to get fancy, you can plug in a second iron, run off a car battery, record preset temperatures, limit your duty-cycle, and open a serial connection.
The controller has an Arduino bootloader on a 32u4 processor, so it looks like a ProMicro to your computer. The system works with the RT series of Weller tips, which have a comprehensive lineup. [Riccardo] also recreated SMD tweezers, and you can find everything at his Tindie store.
Soldering has a way of bringing out opinions from novices to masters. If we could interview our younger selves, we’d have a few nuggets of wisdom for those know-it-alls. If ergonomics are your priority, check out TS100 3D-printed cases, which is an excellent iron, in our opinion.
Read more: Simultaneous Soldering Station — Hackaday
As we’ve said many times in the past, the creation of custom cases and enclosures is one of the best and most obvious applications for desktop 3D printing. When armed with even an entry-level printer, your projects will never again have to suffer through the indignity of getting hot glued into a nondescript plastic box. But if you’re printing with basic PLA, you need to be careful that nothing gets too hot inside.
Which was a problem when [Oleg Vint] started work on this 3D printed case for the popular TS100 soldering iron. But with the addition of a standard 608 bearing, the case provides a safe spot for the iron to cool off before it gets buttoned back up for storage. Of course, you can also use the flip-out perch to hold the iron while you’re working.
As [Oleg] explains on the Thingiverse page for the case, he actually blended a few existing projects together to arrive at the final design. Specifically, the idea of using the 608 bearing came from a printable TS100 stand originally designed in 2017 by [MightyNozzle]. Released under Creative Commons, [Oleg] was able to mash the bearing stand together with elements from several other printable TS100 cases to come up with his unique combined solution.
Solder is the conductive metal glue that one uses to stick components together. If you get the component and the PCB hot enough, and melt a little solder in the joint, it will stay put and conduct reliably. But it’s far from simple.
There are many different solder alloys, and even the tip of the soldering iron itself is a multi-material masterpiece. In this article, we’ll take a look at the metallurgy behind soldering, and you’ll see why soldering tip maintenance, and regular replacement, is a good idea. Naturally, we’ll also touch upon the role that lead plays in solder alloys, and what the effect is of replacing it with other metals when going lead-free. What are you soldering with?
Soldering, and its higher temperature cousin, brazing, are one of essentially two ways create metal-to-metal bonds, and they allow the use of low-temperature techniques that still create relatively stable bonds between two metal surfaces. Soldering is also an interesting chapter in the field of metallurgy, on account of it being based around so-called intermetallic compounds (IMCs).
Welding stands in contrast to soldering, where high temperatures melt the metal on both sides of the pieces that are being joined, permanently fusing them. Welding is a high-strength, high-reliability way of joining metal pieces, but is unfortunately wholly unsuited for delicate electronics where excess heat can damage parts and the goal is more to ‘glue’ electrically conducting elements together than to melt them together.
This also leads us to the reason why soldering and IMCs are such a source of trouble, to the point where IMCs are referred to as ‘evil’. IMCs are essentially bits of the two metal surfaces on either side dissolved into the solder, causing enough of a joining that each side of the joint is more or less stably fused with the solder. Unfortunately such an IMC is a far cry from the stable solid metal of a welding joint, and as a result can be brittle depending on exactly which metals were involved in the solder alloy.
But the IMCs formed in soldering are strong enough, and their formation is at the root of why every solder alloy uses tin. Tin has the property that it is very good at letting other metals dissolve into it. In fact, it’s possible to solder with pure tin, although as we’ll see below, most solder is improved by adding other metals into the mix.