I got my 0603 SMD LEDS, Now I have to Solder Wires to Them

[pickle9000]

So here are my bits.

- I used 1mm lead solder (Kester) and pretinned everything.
- Iron temp was 310deg and the tip was a 3mm chisel.
- I soldered on top of a piece of MDF (medium density fiberboard) and used paste flux (the solder was rosin core).
- The common wire was a single strand of 16 gauge wire pretinned made taught and screwed to the board.
- I marked the back side of the leds with a marker (red and yellow) to indicate the colour in case thy slipped.
- I used a scalpel blade to place and hold each led while soldering, make sure you have metal to metal contact as flux or paste may prevent it from taking. You need to hold it by the substrate not the lens.
- My eyes are poor so I did use a microscope.
- The actual soldering time (per connection) was well under a second. The action was wipe tip, retin tip, wipe tip, touch to connection, done.
- The image looks as if everything is melted (lens) but that is just the flux and it will clean up fine.
- After the first led was in place the rosin from the solder kept the other one there.
- Use as little solder as possible and the fastest soldering time, if you don't the leds will blob together.
- I did not use glue or tape mainly because everything is so close together it would just get ugly. If you do use something try the sticky stuff off of a post it note.

For your application you could turn the wire 90 deg after the common wire is soldered. That will lessen the profile, if you do that place the common wire in a large metal clip (aluminum would be best) and make sure the actual solder touches the aluminum. This will act as a heat sink an prevent the joint from melting.

How are you going to do the crossing lights? I know of a trick with a 4011 that would work perfectly.

[xrunner]

So here are my bits.

...

For your application you could turn the wire 90 deg after the common wire is soldered. That will lessen the profile, if you do that place the common wire in a large metal clip (aluminum would be best) and make sure the actual solder touches the aluminum. This will act as a heat sink an prevent the joint from melting.

Thanks for the suggestions. I put together a small mockup (see attachment). I'm thinking of running the wires out the back through tiny holes I can drill in the mounting block. I have strip styrene I can use for these parts which welds together very easily with plastic welder cement.

How are you going to do the crossing lights? I know of a trick with a 4011 that would work perfectly.

The RR crossing lights? Hadn't thought about it yet, but if these work out OK with the 0603s I will try to use red ones on the crossing signal models I have, because they have tiny lenses that are clear. I could put them behind the lens.

A 4011 NAND gate? Whatcha got in mind? 

[xrunner]

Here's the rig I set up to help me solder the 0603's. I'm soldering to 30 AWG magnet wire. The red and green magnet wire doesn't require stripping because the insulation melts and the manufacturer says it actually acts as flux. However I pre-tinned it anyway before soldering to the LED.

Funny thing is, the amber magnet wire they sell has enamel insulation that has to be stripped off by hand. I don't understand why they can't make that insulation like the red or green. 

BTW - the company is TemCo