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

[xrunner]

LOL - they're tiny. I have red, yellow, and green. I have 36 AWG wire and I need to make traffic lights for an N scale Model Railroad. I need tips on soldering wires to these tiny LEDS. These will be controlled via an Arduino that I already have a program written for which is being tested with larger LEDs.

Any tips are appreciated.   

[c4757p]

Glue them to a piece of thin paper to keep them from moving around. Add a spot of flux, hold the wire against it, and touch with a soldering iron with some solder already on the tip. Repeat for the other side. Just rip it off the paper when you're done, and you can get the rest of the paper off with water and a brush.

You might have a hell of a time getting a good mechanical connection, though. Personally I'd have had a bunch of tiny PCBs made.

[Paul Price]

For testing and working with SMD parts off a PCB:

(1) Use 3M a double sided tape piece to hold the little thing in place on top of a bench vice.
(2) Give the pins a swab with water soluble flux.
(3) Strip silver plated wire-wrap wire #28 to #32 for leads.
(4) With a solder temp just above melting point and with a steady hand solder the WW wire leads to pin after pin.
(5) Clean the finished work with another Q-tip dipped in denatured ethanol.

[xrunner]

Glue them to a piece of thin paper to keep them from moving around. Add a spot of flux, hold the wire against it, and touch with a soldering iron with some solder already on the tip ...

(1) Use 3M a double sided tape piece to hold the little thing in place on top of a bench vice.
(2) Give the pins a swab with water soluble flux.
(3) Strip silver plated wire-wrap wire #28 to #32 for leads ...

OK I'm starting to get the idea.

What I'll need is to have all the cathodes wired together and each R-Y-G LED with it's own wire, so that's four wires going down to the controller. Also need to glue the three LEDs to ... something ... to make it look like a traffic light but that's another issue.

[Paul Price]

Try wiring the LED's with two wires instead of one.
You can buy plastic transparent sheets at some artist, architecture supply or paper stores to create the traffic light lens effect. You can easily create a traffic light using paper to form a tube and fashion sun visors from paper as well and spray paint them to match their traffic pole. Architects often need to create scale models of their designs so architect supply places will offer all types of rods and foam etc. Never underestimate the utility of GOOP, Superglue, or silicon rubber to creating castings. Plaster can then be poured into molds made from wax or silicon rubber.

[millerb]

An 0603 will fit right between the pads on a 2.54mm (0.1") piece of veroboard which you can get cheaply from Radio Shack. Here's a photo of an 0603 resistor on one next to a  buck converter I put together.



I'd just cut a piece of board and tack them down on there instead of trying to solder wires onto them.

[xrunner]

Try wiring the LED's with two wires instead of one.
You can buy plastic transparent sheets at some artist, architecture supply or paper stores to create the traffic light lens effect. You can easily create a traffic light using paper to form a tube and fashion sun visors from paper as well and spray paint them to match their traffic pole. Architects often need to create scale models of their designs so architect supply places will offer all types of rods and foam etc. Never underestimate the utility of GOOP, Superglue, or silicon rubber to creating castings. Plaster can then be poured into molds made from wax or silicon rubber.

Yea I'll have to carefully plan all that so I can get the wires going in the right direction as soldered, if possible. You said to have the iron just above the melting point of solder? Not up at ~650 F or so, but near, say 200F?

[Paul Price]

For the sake of your lungs and that of  the little poor device you are momentarily torturing with heat, keep the heat to a point that will make the solder just flow as a bright shiny liquid,  you need hotter if the solder is like almost melted ice-cream soft in viscosity,  and if you see a lot smoke you are hot enough to make trouble and toast. Heat the joint of wire and device first and as you see the flux evaporate touch the joint, soldering tip and device pin all at once to add a tinsey widdle bit of  solder.

[andyturk]

I bet soldering that QFN was a barrel of fun.

[Paul Price]

Damn, Millerb, your soldering sho' looks nasty! Even Lincoln looks fried.

[xrunner]

Damn, Andyturk, your soldering sho' looks nasty!

Wasn't that millerb's soldering? (it was a quoted pic) 

In any case using that board would end up with a traffic light that was too big for N scale. 

[millerb]

Damn, Andyturk, your soldering sho' looks nasty!

Wasn't that millerb's soldering? (it was a quoted pic) 

In any case using that board would end up with a traffic light that was too big for N scale. 

This is too big?

[Paul Price]

Damn, Millerb, your soldering sho' looks nasty! (On the right side of the LED pictured.)  Left side looks great.

[xrunner]

This is too big?

No ... I said using the pads on that board to make up a traffic light would be too big. 

[Paul Price]

Xrunner, that picture has been magnified! Is isn't really that big.

And taking a second look, Damn, Millerb, your soldering sho' looks nasty! Looks like you nearly fried this LED's both pads, surprised it still lights.  You are not going to get a NASA Certified Soldering merit badge with this kinda work.
Hint: turn down the heat a little, man...and flux around a bit.

[xrunner]

Xrunner, that picture has been magnified! Is isn't really that big.

That's not the issue though. It's the space between the pads. Traffic lights have (proportionally) not nearly that much space between the lights. I understand that the 0603 LED can be soldered onto the pads as shown, but that's not the only concern with regards to my modelling application. 

[DavidDLC]

Can you provide the separation between the LEDs ?

I have a PCB LED matrix with 0603, maybe I can cut something for you depending on the distance.

David.

[TerminalJack505]

Get a cheap piece of balsa wood and cut a shallow grove in it for the wire and a small area for the LED.  Hold the piece of wood down to the bench with mounting putty (Fun-Tak, for example.)  Tin the wire, put it and the LED in place.  Use some flux and put a small amount of solder on the tip.  Steady the wire with your free hand, touch the tip to the LED and wire and Bob's your uncle.  Use a stereo microscope if you have one and you can hardly go wrong.

[andyturk]

Any tips are appreciated.

If you put 3 LEDs on a tiny board, you can probably get OSHPark to make them for pennies. A 2-layer board is $5/square inch (including postage).

[ConKbot]

Xrunner, that picture has been magnified! Is isn't really that big.

And taking a second look, Damn, Millerb, your soldering sho' looks nasty! Looks like you nearly fried this LED's both pads, surprised it still lights.  You are not going to get a NASA Certified Soldering merit badge with this kinda work.
Hint: turn down the heat a little, man...and flux around a bit.

Not like the nasa hand solder standard covers any real SMD work besides the goofy old gull wing packages you have to run though a $5000 lead former first. 

[Paul Price]

Xrunner:  Layout your parts positions and wiring using some free layout software such as PCB123 or equiv. Then print out a copy of the PCB onto film and place it over any substrate you wish (even balsa wood or paper might do the trick.) Then drill the holes and assemble the thingy using your own teensy-weensy wires to make ends meet and you've got watcha want.

[pickle9000]

Here is how I'd do it.

[andete]

There's actually a webshop called ledbaron on ebay [1] that sells among things nicely wired SMD LEDs.

[1] http://stores.benl.ebay.be/ledbaron

[hlavac]

My hands are too shaky for this stuff so i cheat, tin both ends, hold it together with tape or something, and use hot air gun to reflow the solder
Looks much better than when I beat it with soldering iron tip...

[xrunner]

Here is how I'd do it.

Yes, that's what I think I will need to do. I looked around on Ebay last night and found a seller of red, green, and copper colored magnet wire in many gauges -

Magnet Wire

I have some red 30 AWG solid wire and I twisted 4 wires together and it's small enough to look good - either as the type of hanging traffic light (one that hangs above the street on a cable) or to run down a small copper tube. Not only that, but as I've done with other single LED lights I've made by hand, the copper tube acts as the cathode wire, so all you have to do is solder the cathode of the LED at the top and a wire at the bottom of the tube (which can't be seen since it's below grade) and you eliminate one wire. 

The three colors make it easy to wire up at the other end. The stuff is dirt cheap (391 ft for $4) so I think I'll get that and I'll be OK. The hanging twisted wires can simply be painted flat silver or black - I'll have to go look at a traffic light today.