I wanted to do a project using these ws2812b leds, and I find them nearly impossible to hand-solder them because of the tiny contact points. Can someone teach me how to solder these by hand? They are surface mount components as you can see in the images.
I assume you don't have an SMT rework station :)
Put some solder paste on each pad. Place the part on the board. Use a toothpick or something similar to hold it in place, and use your iron to melt the soldering paste on each pad individually. I would guess about two cubic millimeters. If you are not happy with the result, you can touch up each pad individually. Use plenty of flux for the touch-up.
Practice on a scratch board with a dead part first, as it's easy to mess it up if you haven't done it before (but then again, how would I know :) )
Assuming you have clean PCB and diode, and you don't have any special equipment other than soldering station and small chisel tip. If you don't have soldering station, buy one, even a cheapo from AliExpress.
These diodes aren't hard to solder at all. They have huge pads which extend outside the package. With a tiny bit of technique this can easily be done.
- If you design the PCB, ensure that pads are larger than the diode so that you can touch the PCB pad with your soldering iron and not just LED pad.
- Add flux onto PCB pads
- With your soldering iron, add a tiny bit of solder to each of the pads so that each has noticeably convex amount of solder. There should be just enough solder to coat LED pad and not more than that.
- Add more fresh flux (you can never have too much flux)
- Place diode and delicately press it (so that it doesn't move anywhere) while you
- Delicately touch either just the PCB pad or both PCB pad and LED pad with your soldering iron, at the same time. Wait just enough for the solder to melt and visibly coat the LED pad. With well set temperature this should take half a second to a second.
- Clean the flux off the diode and the PCB
- If you don't have good technique, you will be safer using leaded solder. Leaded solder melts in lower temperature which means you have more margin for error before you destroy the LED. I use leaded solder exclusively because it makes my life easier.
- Set correct temperature on your soldering station. You want it just enough to melt the solder comfortably and that's it. Each station reacts differently and will require different setting, and frequently also different setting depending on what you are soldering. You need to experiment with it.