Once you’ve been tinkering around with electronics for a while, you’ll realize the through-hole components that make breadboarding a circuit so easy won’t cut it anymore. Surface mount parts are the future, and make it incredibly easy to build a semi-professional mockup at home. The question arises, though: how do you store thousands of surface mount parts smaller than a grain of rice?
As [George] was building up his SMD inventory, he came across a few clever solutions. The first was a binder sold by Adafruit (and others) that holds strips of cut tape SMD components. [George] wanted something a little more modular, and when he came across an eBay auction for 5000 0805 resistors and 3000 0805 caps, he needed to find a storage solution.
[George] ran across these tiny modular boxes while shopping at Adafruit. These boxes are completely modular, interlock with each other, and have a hinged lid that will hopefully prevent the eventual, ‘SMD parts everywhere’ spill everyone his likely to have.
After printing out some labels for his boxes, [George] had a very tidy solution to his SMD organization problems. We’re wondering what other Hackaday readers use to organize their parts, so if you have a better solution send it in.
Gone are the days when all the cool chips are able to be thrown into a breadboard very easily. [starlino] was working with a circuit that uses an accelerometer, but unfortunately these chips come in hard to solder LGA-16 packages. [starlino] figured out a way to prototype with these packages that doesn’t require a custom breakout board or spending any time watching a reflow oven.
[starlino]’s LGA-16 adapter board began with a piece of perf board drilled out to form a space that perfectly fits his accelerometer. A piece of tape is placed over the pads of the chip and perf board, and the gap between the chip and board is filled in with a two-part plumbers putty.
Once the putty has cured, the leads on the acclerometer are connected to the pads on the board with a silver conductive pen. After putting a few header pins in the corners of the board, [starlino] soldered the pads to the pins and had a permanent breakout board for a very small accelerometer.
It’s not by any means a pretty build, but after [starlino] sealed the entire build in liquid electrical tape and installed it in a DIP socket, he had a completely functional accelerometer in an easy to prototype package. Not bad for a breakout board that can be built from stuff just lying around a workbench.
For those that have always felt a bit treppidatious when approaching SMD, you can relax. Here’s a simple guide to walk you through your first shaky steps into surface mount devices. Distributed freely under the creative common license, the Manga Guide to SMD is an 18 page comic that has a goal of making SMD producers out of all of us. There’s a good visual explanation of what SMT is and why we use it, as well as a thorough walk through of how to solder the tiny devices with your soldering iron. They don’t go into dealing with a small reflow oven in this issue.
If this fits well with your learning style, you might also be interested in the Manga Guide to Electricity.
Here’s an oldie but a goodie. [RunnerPack] stumbled upon an article from 2001 about building a stereo microscope from a pair of binoculars and a camera lens. With a ring light attached to the end of the camera lens, we couldn’t think of a better microscope for SMD work.
To mount the binoculars to the camera lens, [Giorgio Carboni] made a very nice adapter containing four prisms. These prisms are very carefully aligned and glued down with a little bit of epoxy. By using an 8×30 pair of binoculars and a 35-100 mm camera lens, [Giorgio] was able to get a magnification factor of 10-57x. With a macro lens this factor can be increased (a 28mm lens bumps it up to 71x, but a lot more light is needed).
The pedestal is just a few ground rods and ground steel rods, something that requires a bit of machining. Since 2001, though, a lot of tinkerers have 3D printers so it could be possible to build a more easily manufactured version of the focusing apparatus.
[RunnerPack] had a pair of binoculars and a camera lens handy and tried a mono version of this build. He says he was blown away, but unfortunately didn’t provide any pictures. If you decide to build this project, be sure to snap a few pics and send it in on the tip line.
[Adam] was tired of plopping the same components over and over into his Arduino-based designs. He spent part of his weekend laying out a small board that would host everything he needed and could be built as a single component for all future projects. Above you can see the project he calls SMDuino, an Arduino clone that can be used as a surface mount part.
The contacts on four sides of the board break out the pins. They’ve been designed with 0.1″ pitch which means they will work with standard pin headers. But since they’re plated through from top to bottom they are easy to solder to surface mount pads as well. The project is open source, so you can order your own boards (he used DorkBot PDX) or email him if you want to get in on a pre-order. That is for unpopulated PCBs only. But there’s few components used here so it’s pretty inexpensive to throw together. You’ll need four caps, four resistors, a crystal, an LED, the ATmega*8 of your choice (an ATmega328 is used here), and a low dropout regulator. Of course it is possible to go without the crystal oscillator.
Does this remind anyone else of the Basic Stamp 2?
We try to stick to the 0805 parts because they’re still big enough to solder by hand. But [Scott] shows us that it doesn’t take too many special tools to reflow fine-pitch components at home. In this case he’s using 0402 resistors, a footprint that we consider functionally impossible to solder using an iron.
The two parts of the equation that he spent some money on are professionally produced PCBs and a solder stencil. The stencil is laser-cut from Kapton, which is heat-resistant so it doesn’t warp during the cutting process. An acrylic frame holds the PCB in place, and he just tapes the stencil over it and uses a chunk of acrylic as a squeegee to evenly apply the solder paste. Splurging on the PCB and stencil means you’ll achieve tolerances which lead to success.
The next issue is placing the components. [Scott] shows off some vacuum tweezers he built using an aquarium pump. Watch the video after the break to see how small those 0402 parts are when he extracts one of the resistors from the tape packaging. With the board manually populated (check everything twice!) he moves the board to a completely unaltered toaster oven for reflow. We have seen a lot of projects which add controllers to these ovens, but he really makes the case that you don’t need it. Instead, he uses a thermocoupler read by a multimeter just to let him know what’s going on with the temperature. He uses a smart phone as a timer, and switches the oven on and off to match the solder’s heat profile. Continue reading “Fine-pitch SMD soldering with minimal tools”
SMD components have a lot of advantages over the through-hole parts our fathers and grandfathers soldered. Working with these tiny surface mount components requires a larger investment than a soldering iron and a wire-wrap gun, though. Here’s a few reflow ovens that were sent in over the past week or two.
[ramsay] bought a 110 V toaster oven off of eBay. Even though [ramsay] is in England and has 230 V mains, everything in the oven is mechanical and works just fine with a higher voltage. His first test didn’t go quite as planned; the solder paste wasn’t melting at 120° C, so he cranked up the temperature and learned that the FR in FR-4 stands for flame retardant. Never deterred, [ramsay] decided to build a controller so the temperature ramps up and cools off at the right rates for the flux and paste to do their thing.
Solder paste has a temperature profile that requires the board to be kept at a temperature between 150° and 180° C for a minute or so before climbing up to 220° for a second so the solder will melt. [Nicolas] had the interesting idea of putting a USB port in his toaster oven and storing the heating profiles on his desktop. The build uses an MSP430 microcontroller to turn the relays powering heating elements on and off. [Nick] is working on a C# desktop app to monitor and regulate the oven temperature from his computer, so we’re fairly interested in seeing the final results.
Watching the SMD self-alignment videos on YouTube is a lot more fun than messing around with tweezers, stereo microscopes, and extremely fine soldering irons. If you’ve got a better idea for a toaster/reflow oven, send it in on our tip line and we’ll check it out.