Long-time Slashdot reader wonkavader found a video on YouTube where, at the 2:50 mark, there’s time-lapse footage of soldering paste magically melting into place. The secret?
Many circuit boards include a grounded plane as a layer. This doesn’t have to be a big unbroken expanse of copper — it can be a long snake to reduce the copper used. Well, if you run 9 volts through that long snake, it acts as a resistor and heats up the board enough to melt solder paste. Electronics engineer Carl Bugeja has made a board which controls the 9 volt input to keep the temperature on the desired curve for the solder.
This is an interesting home-brew project which seems like it might someday make a pleasant, expected feature in kits.
Hackaday is impressed by the possibilities too:
Surface mount components have been a game changer for the electronics hobbyist, but doing reflow soldering right requires some way to evenly heat the board. You might need to buy a commercial reflow oven — you can cobble one together from an old toaster oven, after all — but you still need something, because it’s not like a PCB is going to solder itself. Right?
Wrong. At least if you’re Carl Bugeja, who came up with a clever way to make his PCBs self-soldering…. The quality of the soldering seems very similar to what you’d see from a reflow oven…. After soldering, the now-useless heating element is converted into a ground plane for the circuit by breaking off the terminals and soldering on a couple of zero ohm resistors to short the coil to ground.
It’s an open source project, with all files available on GitHub. “This is really clever,” tweeted Adrian Bowyer, inventor of the open source 3D printer the RepRap Project.
In the video Bugeja compares reflow soldering to pizza-making. (If the circuit board is the underlying dough, then the electronics on top are the toppings, with the solder paste representing the sauce that keeps them in place. “The oven’s heat is what bonds these individual items together.”)
But by that logic making a self-soldering circuit is “like putting the oven in the dough and making it edible.”
Read more of this story at Slashdot.