This is how I solder small SMD LEDs. Thanks to okyoskar_1.87 who demonstrated this easy technique. For me, I would be using those grey 3M double-sided tapes instead as their glue kind of last longer against the soldering iron’s heat.
So, just lay the SMD LEDs with their solder contacts face up. They are polarity sensitive so you need to know which end is the negative side which are often identified by green arrows or top hats. Tin the solder pads and the wires, then place the wire on top of the LED’s solder pad and tap the soldering iron tip in them. If you want, you can place some solder flux as well, on to the LED’s solder pad first. After all that is done, use a sharp cutter to trim off the excess wires sticking out. This works with SMD LEDs from 0603 onwards. I have not tried with 0401’s which are to tiny and you need even smaller AWG wires for them.
You still have to trat them as fragile as a simple pull of the wires can separate the solder pad from the LED and it is then spoilt.
