Make sure those tiny parts know their place by using this surface mount solder assistant (translated). It’s like a clamp for small packages; gravity and a needle to hold them in place while you do some hand soldering. [Red Devil] started the built by soldering together some brass rails into a hinged frame with a clamp to accept the needle tip. Next, a pair of tubes were added to accept LEDs which light the work area (we think that’s a fantastic touch). Finally, the assembly was mounted to the corner of a square base that makes up the work surface.
This is basically a complex version of a simple gravity clamp. But if you’re doing some assembly line soldering this would be indispensable. For this kind of work, custom jigs are often built. That would still be the case, but this armature removes the need of building something into each jig to hold the SMD components in place.
For SMD work, solder paste and a heat gun is great. Heat guns aren’t the cheapest thing, so [Karel] decided to make cheap reflow oven out of a toaster oven. With a PCB taken from a laminator temperature control board, the build was fairly successful, so [Karel] decided to add a thermistor to his oven.
There was a problem with placing this thermistor near the board: solder melts in a reflow oven, so [Karel] needed to figure how to connect the thermistor to the control board outside the oven. The solution was crimping thin copper tubing to the thermistor leads and passing that tube through the wall of the oven. Epoxy was used to avoid an electrical short. A low tech solution, but very effective. After applying some solder paste and going in the oven, this board looks very clean. There are a few solder bridges, but nothing a wick can’t take care of.
[Karel] is now working on an update to the temperature controller that controls the oven over a serial connection. Check out the video of a few temperature cycles after the break.
Continue reading “Toaster oven forgoes Pop-Tarts, reflows solder”
[Augusto] wrote in to tell us about his keychain-sized persistence of vision project. He built the original prototype on some protoboard, using a PIC 16F627 to drive eight LEDs. Synchronization is managed by a tilt sensor on the board that starts the strobing to match the direction the board is traveling. This is a similar setup as the POV device that used an accelerometer, but it should be quite a bit easier to code for the tilt switch.
Once [Augusto] had the hardware dialed in he set to work laying out a surface mount design. The two AAA batteries were traded for a single 3V coin cell, which is on the back side of the board you see above. This is his first attempt at working with surface mount components and we think he did a great job. Check out the POV in action in the video after the break.
Continue reading “POV keychain from prototype to SMD board”
Need to use that antiquated hardware that can only be connected via a parallel port? It might take you some time to find a computer that still has one of those, or you could try out this USB to Parallel port converter. It’s not limited to working with printers, as the driver builds a virtual parallel port that you should be able to use for any purpose. But what we’re really interested in here isn’t the converter itself, but the build process. [Henrik Haftmann] posted a three-part series of videos on the assembly process, which you can watch after the break.
The build is mostly surface mount soldering with just a handful of components that need to be hand soldered. The first of his videos shows him stenciling solder paste onto the boards. From what we can see it looks like he built a nice jig for this using scrap pieces of copper-clad which match the thickness of the PCB, and hold it and the stencil securely in place. There’s a bunch of other tips you can glean from the videos, like the image seen above. It’s a clamp that holds the PCB and USB jack together while they are soldered.
If you’re ever thinking of assembling a bunch of boards you should set aside thirty minutes to watch them all.
Continue reading “One-man SMD assembly line shares a lot of tips about doing it right”
[Noel] does a lot of SMD work and wanted a pair of “smart” tweezers that could be used to place components as well as for reading their capacitance and resistance values on the fly. As we have seen, these things can be somewhat costly, and not really necessary if you already have a good multimeter. With that in mind, he figured he could build his own for almost nothing.
He started off with a pair of kids’ “training” chopsticks which are durable, but more importantly, non-conductive. He took a second pair of tweezers, this time made of metal, and split them in two. He soldered wire to a set of ring terminals, mounting one on each leg of his broken tweezers. The final bit of assembly involved using zipties to mount everything on the plastic chopsticks along with the addition of banana plugs to the end of his probes.
[Noel] says that the tweezers work quite well, and with such a low price tag, we can’t argue.
A Hack a Day reader needed a tool to solder a lot of SMD parts, so he built a DIY heat gun, and we’re impressed with the results.
After trawling the internet looking for ideas for his heat gun, [MRGATZ85] found that most builds used the ceramic element from cheap soldering irons. Experiments in this direction didn’t go very well because the ceramic element in these irons tends to fall apart very easily. In a moment of inspiration, [MRGATZ85] realized he had an old vaporizer lying around and decided to take it apart. To his surprise, the vaporizer element was a great size, self-contained, and most importantly free. After fabricating a case out of high-temperature foam, aerosol cans, and deadbolt parts, [MRGATS85] was left with a very nice build.
Aside from SMD work, a heatgun can be a very valuable tool for PCB stripping and being used for solder reflow. We’re a little surprised we haven’t seen a homebrew heat gun in quite a while. Even though the element is surrounded by high-temperature foam, the gun still gets a little hot to the touch. We’re hoping that will eventually be under control; it’s a very useful build otherwise.
Check out the image gallery, or the video demo after the break.
Continue reading “Homebrew heat gun from scrounged parts”
Drag soldering works exactly as its name implies, by dragging a bead of solder across fine-pitch pins you can quickly solder an entire row. The method relies on clean joints, so liquid solder flux is often used to make sure there is good flow. But if you’re drag soldering on boards that you’ve etched yourself the solder can sometimes run down the trace, rather than staying where you want it. Professionally manufactured boards don’t have this problem since they have solder mask covering the copper that doesn’t need soldering. [Ahmad Tabbouch] has a method that uses Kapton tape to act as a temporary solder mask on diy boards.
The process involves several steps. First, three strips are place horizontally across the board, leaving just a portion of the upper and lower pads exposed. Those pads are then tinned with solder, and a light touch with an X-acto knife is then used to score the tape covering the vertical rows of pads. Once the waste as been removed, two more strips are added and those rows are tinned. From there the chip is placed and soldered as we’ve seen before; first tacked in place, then fluxed, and finally drag soldered to complete the connections. This achieves a crisp and clean connection, presumably without the need to clean up your solder mess with solder wick.
Kapton tape resists heat, making it perfect for this process. We’ve also seen it used on hot beds for 3D printers, and as a smoothing surface for sliding mechanisms.
[via Dangerous Prototypes]