Briefly about soldering
What should you know when soldering electronics? If you're picking up a soldering iron for the first time, start by practicing on wires or a test board. Don’t ruin your electronics. And make sure to read the entire list before starting.
-1. Prepare the room for soldering
Inhaling toxic fumes and burning your desk is a bad idea. You need a ventilated space, whether it's a desk by the window or a DIY fume extractor on the table. Solder on a wooden surface or a soldering mat to avoid damaging furniture. Buy a magnifying glass and a "third hand" (tool); they will definitely come in handy. Use a good lamp to ensure you can clearly see what you're doing. Remove distractions—children, pets—so you don’t accidentally burn anyone.
0. Buy a proper soldering iron, solder, and flux
The most popular soldering irons for this hobby are Hakko T12, Pine64, TS100. They have tips that heat up well, unlike soldering irons where the tip is just a "cap" on the heater. AliExpress has plenty of spare tips of all standards.
As for solder, the ideal ratio of tin to lead is 60/40. This solder melts easily at 280°C and is suitable for most tasks, from soldering chips to power wires.
Regarding flux, it should match the material you're soldering. Ideally, use neutral flux, though it’s still recommended to clean up any residue with alcohol after soldering. Do NOT use acid for soldering wires—unless you want oxidation and disconnection under the silicone insulation. Rosin can work, but jelly flux is more convenient. For example, TT Flux Gel is a good option.
1. Set the correct temperature
For soldering thin wires with 60/40 solder, 280°C is enough. For power wires (12-14AWG), you’ll need 400-450°C depending on the tip size and your soldering skills. The key is not to overheat the board.
2. Ensure the tip heats to the set temperature
You can’t really check it by feel or with a thermometer, but if the soldering iron heats up and the solder doesn’t melt on contact, something is wrong.
3. Clean the tip
Always keep a sponge handy to clean the soldering tip. A clean tip grabs the solder better and won’t introduce dirt into your soldering area.
4. Tin the soldering points
Apply flux to the untinned contact. It's better to hold the wire or board with tweezers or the third hand to avoid burns. Simultaneously bring the tip and solder to the contact, waiting until the solder spreads across the necessary area. Don't overheat it so the solder doesn’t flow under the silicone insulation of the wire (this will result in a stiff part of the wire, which, at the very least, doesn’t look nice) and to avoid small components on the board moving due to overheating.
If soldering connector contacts, use the mating connector to keep them in alignment.
5. Solder confidently
No need to panic! Everything will work out if you’ve followed the steps above. Here’s the key part: firmly press the wire and the soldering pad together. If there’s enough solder on them, apply the broad side of the tip at the correct temperature and hold it until you get a smooth joint. Don’t wiggle the iron around! Just heat it well. Once the solder melts and the two parts become one, carefully remove the iron to avoid creating a messy blob. If you skimped on solder during tinning, add some during the soldering process. Don’t overdo it, but don’t skimp either—you need a solid connection. If the joint isn’t shiny, add more flux and reheat so the solder spreads evenly.
If it doesn't spread properly, something's wrong. Reread the instructions above.
6. Make sure you haven’t knocked off nearby components
If you were soldering on a board, you might have accidentally knocked off a small component nearby with the iron. Visually check that everything is in place.
7. Clean the soldering area
Clean the tip with a sponge. Use alcohol and a synthetic brush or cotton swab (as long as it doesn’t leave fibers) to remove flux residue on the board. Check that no solder balls remain on the board behind components or between contacts. Slide heat shrink tubing over soldered wire connections or between a wire and connector. Clean up any remaining solder from the mat or surface you were working on so it doesn’t get on your drone (motor magnets are great at picking up all kinds of debris). And organize your tools to avoid turning your desk into a mess.
8. (Optional) Use coating to protect boards
After ensuring everything is done correctly and no further soldering is needed, coat the board with coating to protect it from dust, moisture, and accidental short circuits from external contacts. Use special sealants/lacquers for this purpose. You can learn more here.
Congratulations, now I’m proud of you! I hope soldering brings you as much joy and usefulness as it does for me.