So, You’re Scared Of Surface Mount

If you are lucky enough to encounter a piece of homebrew electronics from the 1950s, the chances are that under the covers the components will be assembled on solder tags, each component with long leads, and chassis-mounted sockets for tubes. Easy to assemble with the most agricultural of soldering irons.

Open up a home build from the 1960s or early 1970s, and you might find the same passive components alongside germanium transistors mounted through holes in a curious widely spaced stripboard or even a home-made PCB with chunky wide tracks.

By the late 1970s and early 1980s you would find a more familiar sight. Dual-in-line ICs through-hole on 0.1″ spaced stripboard, and home-made PCBs starting to appear on fibreglass board. Easy to use, easy to solder. Familiar. Safe. Exactly what you’ll see on your breadboard nearly forty years later, and still what you’ll see from a lot of kit manufacturers.

Nice and familiar, a through-hole Arduino. By Nicholas Zambetti -, CC BY-SA 3.0
Nice and familiar, a through-hole Arduino.
By Nicholas Zambetti CC BY-SA 3.0

But we all know that progress in the world of electronic components has not stood still. Surface-mount components have a history going back to the 1960s, and started to appear in consumer equipment from the end of the 1980s. More components per square inch, smaller, cheaper devices. Nowadays they are ubiquitous, and increasingly these new components are not offered in through-hole versions. Not a problem if your experiments are limited to the 741 and the 555, but something that rather cramps your style if your tastes extend to novel sensors for a microcontroller, or RF work.

This development has elicited a range of reactions. Many people have embraced the newer medium with pleasure, and the project pages are full of really clever SMD projects as a result. But a significant number have not been able to make the jump to SMD, maybe they are put off by the smaller size of SMD components, the special tools they might require, or even the new skills they’d have to learn. When you sell a kit with SMD components these are the reactions you will hear from people who like the kit but wish it was available in through-hole, so this article is for them. To demystify working with SMDs, and to demonstrate that SMD work should be within the grasp of almost anyone who can wield a soldering iron.

But They’re So Tiny!

Tiny SMDs - fortunately most of which you will not have to worry about.
Tiny SMDs – fortunately most of which you will not have to worry about.

It’s likely to be the first reaction from a lifelong through-hole solderer. SMD parts are often very small indeed, and even those with larger packages can have leads that seem as numerous and thin as the hairs on a cat when seen with the rabbit-in-the-headlights panic of the uninitiated.

But it is important to take a step back and understand that not all SMDs are created equal. Some of them are grain-of-sand tiny and only hand-solderable by those with God-like powers, but plenty of devices are available in SMD packages large enough for mere mortals.

So don’t worry when you look at a board covered with grain-of-dust-sized components. Very few people could attempt that level of construction, your scribe certainly can’t. (We await commenters claiming to routinely hand-solder thousand-pin BGAs and 01005 chip components with anticipation, however such claims are useless without proof.)

Instead, concentrate on the SMD packages you can handle. SMD chip component packages are refered to by a number that relates to their dimension. Confusingly there are both metric and imperial versions of the scheme, but the format is the same: length followed by width.

Consider the picture above with the PCB and the tape measure, it’s the underside of a Raspberry Pi model B+, and will have been assembled by a robotic pick-and-place machine. The majority of the components are very tiny indeed, but you will notice L3 as the black component towards the bottom left that looks huge compared to its neighbours. That package is a “1008”, 0.1 inches long by 0.08 inches wide. It’s still tiny, but imagine picking it up with a pair of tweezers under a magnifying glass. Not so bad, is it. You’ve probably handled plenty of things in that size range before, do SMD parts seem so scary now? The larger components – 0805, 1008, and 1206 – are surprisingly within the grasp of the average maker.

But I need all sorts of special tools!

Retro Populator, a homebrew pick-and-place machine we featured back in 2014
Retro Populator, a homebrew pick-and-place machine we featured back in 2014

In a commercial environment an SMD device will be assembled by machine. Glue or solder paste will be printed in the relevant parts of the board, and a robotic pick-and-place machine will retrieve components from their tape packaging and automatically place them in their correct orientations. The board will then be soldered all-at once, either in a reflow oven or by a wave soldering machine.

If you’re new to SMDs you are unlikely to have any of this kit just lying around on your bench. There are self-built pick-and-place machines and a host of self-built reflow ovens, but it’s safe to say they’re still quite an advanced thing to have.

You’ll also see all manner of commercial kit aimed at the bench-top SMD constructor. Hot air soldering stations or SMD bits for conventional irons, all of which are very useful but come with a hefty price tag.

The good news is that you don’t need any of these special tools to dip your toe into the SMD water. You almost certainly already have everything you need, and if you don’t then very little of what you lack is specifically for SMD work. If you have the following items then you are good to go:

A basic SMD soldering toolkit
A basic SMD soldering toolkit

A good light source. Even the larger SMDs are still pretty small. Plenty of light ensures you will be able to see them clearly. A good downward pointing desk lamp should suffice. A clear high-contrast surface. Because SMDs can be difficult to see, it helps if they are manipulated over a bright white surface. A fresh sheet of white printer paper on a desk makes a suitable working area. Good hands-free magnification. Unless you are fortunate enough to have amazing eyesight, you will need a decent magnifier to work with surface-mount components. The “Helping hands” type on a stand are suitable. A very small flat-blade screwdriver. You will need this to hold surface-mount components down while you solder them. A good-quality set of precision metal tweezers. You will need these for picking up, manipulating, and turning over surface-mount devices. A fine-tipped soldering iron. If you have a standard fine tipped iron suitable for use with conventional 0.1” pitch through-hole components then you should be well-equipped.

That said there is one special tool that might be worth your consideration. Holding an SMD device while soldering it can sometimes seem like a task that needs three hands, so one or two tools can be found to help. Fortunately this is something you can build yourself. Take a look at the SMD Beak, a weighted arm for example, or your scribe’s spring clamp third hand.

I’m sorry, this is just beyond my soldering skill level

Desolder braid and plenty of flux are your friends.
Desolder braid and plenty of flux are your friends.

It is easy to imagine when you are looking at an SMD integrated circuit that its pins are just too small and too close together, you couldn’t possibly solder them by hand. The answer is that of course you can, you simply need to view how you solder them in a different way.

With a through-hole IC you solder each 0.1″ pitch pin individually. It is something of a disaster if you manage to put a solder bridge between two pins, and you race for your desolder pump or braid.

With a surface-mount IC by comparison there is little chance that you as a mere mortal could solder each pin individually, so you don’t even try. Instead you solder an entire row at once with an excess of solder, and remove the resulting huge solder bridge with desolder braid to leave a very tidy and professional-looking job. Surface tension and plenty of flux are your friends, and there is very little soldering skill required that you do not already have if you are an experienced through-hole solderer.

If you can hold it down onto the board and see it clearly with your magnifier if necessary, then it doesn’t matter what the component is, you can solder it. Give it a try, you’ll surprise yourself!

What next?

1206 chip discrete components hand-soldered to a PCB
1206 chip discrete components hand-soldered to a PCB

So we hope we’ve convinced you as an SMD doubter, that you have the ability to work with SMDs yourself. What next?

Start by reading up on the subject. Your favourite search engine should deliver, tutorials can be found from Sparkfun, from Adafruit, or from Instructables among many others. And look for videos, YouTube has a huge number of SMD soldering guides.

But there is no substitute for practice. Find a scrap board populated with reasonably-sized surface-mount components, and have a go at reworking it. Desoldering its components may be a bit difficult, but you should easily be able to rework the solder joints. Slather an integrated circuit’s pins with flux, and try running a blob of molten solder along them, then removing the excess with desolder braid. The great thing about a scrap board is that it doesn’t matter if you damage it, so you can practice these techniques to your heart’s content until you are satisfied with your new-found skill.

So you’re ready to move forward, and make your first SMD project. Well done! What you do next is up to you. Design your own circuit and get a PCB made, buy a kit, or find an SMD project you like on with downloadable PCB files and order your own.

Whatever you do, be happy that you’ve conquered your SMD fears, and resolve to be first in the queue to try any new technology in the future!

DIY Hakko Soldering Station

[Julez] wanted another soldering station, so he decided to build one himself using a Hakko 907 soldering iron (or a clone). Of course, he could have bought a station, but anyone who reads Hackaday doesn’t require an explanation for why you would build something you could buy.

The station has two switchable outputs so you can use two different irons (perhaps with different tips) although you can only use one at a time. [Julez] bought a case with a transparent top from eBay and also got a digital temperature controller from eBay, which is the heart of the project. As for the actual iron, you can find clone versions of the 907 handpiece for well under $10.

Because the station uses a module, the actual wiring isn’t terribly difficult. There’s a pot to control the temperature and the controller directly connects to the iron’s heating element and temperature probe. There’s also a standby switch that reduces the temperature using a fixed resistor in series with the control pot.

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BGA Hand Soldering Video

By 2016, most people have got the hang of doing SMD soldering in the garage–at least for standard packaging. Ball Grid Array or BGA, however, remains one of the more difficult packages to work with [Colin O’Flynn] has an excellent video (almost 30-minutes, including some parts that are sped up) that shows exactly how he does a board with BGA.

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The Internet of Reflow Ovens

Using a toaster oven to reflow solder isn’t a new idea. But [Sukasa] wanted something that had more features and improved appearace. So he married a Netduino, a toaster oven, and some solid state relays to made a clean-looking reflow oven. His goal was to have nothing look like an overt modification to a casual observer. Inside, however, the oven now has a network connection for system status via a Web browser or JSON.

The new brains of the oven are a Netduino Plus 2 and an I2C port expander that connects to a few extra I/O devices. The challenging I/O, though, is the heaters. When cold, the oven can draw over 16 amps, so a pair of 12A solid state relays in parallel handle that load. There are also two fans: one to keep the electronics cool and another on software control. An IGBT allows the controller to pulse width modulate the fan’s output. A pair of MAX31855s read the thermocouples that report the temperature.

lcdThe controller was a mashup of the existing oven’s keypad and an add-on LCD display (see right). One thing we didn’t see was a schematic. Of course, you can read the code and figure out how it is all connected and (unless you use the exact same oven) you are probably going to need to modify things to suit your particular setup, anyway.

We’ve seen other good looking reflow oven and controller builds in the past, including one with a touchscreen. It is also worth noting that you can find reflow ovens at relatively low prices now if you don’t feel like rolling your own.

Review: Voltera V-One PCB Printer

Back in Feburary, I was one of the first people to throw some cash at the Voltera V-One circuit board printer on Kickstarter. With an anticipated delivery date of Q4 2015, I sat back and waited. This week, my V-One arrived!

I’ll preface this article by pointing out that I do know the folks at Voltera as we went to university together. That being said, I did put down my own cash for the device, so I’ve bought the right to be critical. I also have no relationship with their company. In this article, we’ll go through unboxing and printing, then get into a review of the V-One based on what we’ve seen so far.

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Hackaday’s DC Meetup and Workshops

Washington DC has a vibrant hardware hacking community and it was out in force on Saturday night. We had over one hundred people through the door at Nova Labs in Reston, Virginia (DC metro area). This sleek and spacious hackerspace opened their doors for a Hackaday Meetup as part of a weekend packed full of activities.

The building that Nova Labs moved into not too long ago is a really well-suited area for a Hackerspace. The front half of the building includes a huge open space which has plenty of room for people to set up the hardware they wanted to show off. The back has a full woodshop, machine shop, and more, with classrooms and conference rooms in between.

Above are a set of hats with addressible LED strings wrapped around them which [ArsenioDev] brought along with him. Several members of the Wyolum team are involved with Nova Labs and they were showing off some LED matrix-based projects like the marquee cube and a 3-player reaction time game. And clacking away all night long is a vintage teletype machine that [Bob Coggeshall] fixed and connected to a Raspberry Pi.

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Surface Mount Soldering Workshop Shares Secrets of CM

Friday afternoon I had the pleasure of sitting in on a surface mount soldering workshop. I’ve done some surface mount soldering before and am quite adept with a soldering iron, but this focused on solder paste and a hot air pencil. [Bob Cogeshall] ran the workshop and went beyond the most basic information. His experience founding Small Batch Assembly, a contract manufacturer whose offices are in the Nova Labs hackerspace, has led him to learn a lot of tricks of the trade.

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