How to Easily Solder Wires to SMT LEDs

The Problem
There are a lot of cool applications where you need to embed small surface mount LEDs into things like clothing, jewelry, etc. In order to do so, you need an easy way to solder small magnet wire to the tiny LEDs. There have been other attempts at making this an easy process, but I have found nothing as simple, quick and easy as this new method.

The Solution - Duct Tape
The process is basically simple. We need to hold an SMT LED upside down so we can hand solder wires to it. The best way to hold the LED is to attach it to a piece of duct tape. Magnet wire (30 guage) is probably the best size for most applications. If you use two colors - one red, the other green, you can show the polarity of the LED during final assembly. If you don't use two colors, you will need some other way to mark the polarity.

Here are the steps:

Step 1:
Use masking tape to mount a square of duct tape upside-down (sticky side up) to a flat surface.

Step 2:
Set your LED upside-down on the duct tape and press to make sure it is firmly attached. To save time, you can mount several LEDs in one big column. Make sure each LED is facing the right way polarity-wise. The polarity is shown in the photo above.

Step 3:
Pre-tin your magnet wire ends. This is the most time consuming step. A solder pot would make it go much faster.

Step 4:
Add a small solder bead to each pad of the LEDs. Just a small dab is all that is needed.

Step 5:
Hold the magnet wire on the LED pad and heat with soldering iron. When the solder melts, remove the iron. Hold the wire steady until the solder solidifies. If you use a lighted magnifier to see better, this step is amazingly fast and easy, provided you have a steady hand.

All Done
When done soldering, the LED lifts easily from the tape and is ready to embed in your project. Don't forget to use current limiting resistor on your PCB or elsewhere for attaching the LEDs to.

Comments

[Johin_Manning_1985]

Can anyone give me some advice on which is the best soldering iron to use for this project?

This is what I am looking at right now…

[marciokoko]

oh wait! If magnet wire was,ia net zed t would be awesome!

[Ralphxyz]

SMT surface Mount Technology

SMD Surface Mount Device

A SMD uses SMT to be mounted, normally to a PCB (Printed Circuit board).

Thanks ProvideYourOwn, very helpful strutable!!

[Yonatan24]

"strutable"?

[Ralphxyz]

Yeah "strutable": with the knowledge gained one is able to strut proudly!!

[zack247]

SMD, SMT, PCB.. so many abbreviations! :P

[MerlinMakes]

me thinks this field's (electronics) purpose in life is to make abbreviations.... AVR, SOIC, IC, MC, SMD, SMT, PCB, DIP switches, AC, DC, it's no wonder it's so bloody hard to actualy learn this stuff. it's written in marsian.

[Nobin]

Very good job and idea, thank for share.

[KevinAlien26]

What makes magnet wire so useful for SMT components?

[sreeci]

First of all, the term "Magnet wire " is illogical and uncalled for a single strand lacquer or varnish coated (for insulation) copper wire. Kevin, it also confused me when I read the description. I thought why do we need a wire that's magnetized?
Well It's a simple single strand Copper wire used for transformer winding, and it's used for soldering SMD LEDs because it's very thin and undetected where ever the SMD LED is used.

[KevinAlien26]

Ahh clarification! Thank you :) lately I've been trying to ask as many questions as I have and I appreciate being answered. Can I simply use the wire from an old transformer or should I use new wire?

[blounsb999]

Kevin, I've been dealing with 'magnet wire' for the past few months now while winding guitar pickups. Mostly 42 gauge - hair thin. I think... THINK... the term comes from its use in electromagnets.

[killbox]

recycle away! just remember that that kind of wire looks like it has no insulation, but it really does. the easiest way to get the enamel paint off the ends so you can solder them is with a quick run through a cigarette lighter flame and then some fine sandpaper or steel wool.

[avengine]

very good idea.
where do you buy the magnet wire? and what is the advantage for using this?

[ApprenticeWizard]

You also can get Wire Wrap wire, which is very fine wire (similar to magnet wire), but has insulation in multiple colors.

[ProvideYourOwn]

I buy it from e-bay. Search for 'magnet wire XX gauge', filling in the gauge you want. I used 30 gauge for this project. You can get all gauges, lengths and colors. I don't recommend harvesting from transformers as it will come with the goo/glue that is used to hold it together, plus it is a lot of work. Also, be sure to get the heat strippable (or solderable) kind - see my solder pot tip I recently posted for how I found to easily strip the insulation from the ends.

The advantage as far as I am concerned is the small size. It is small enough to be used for jewelry purposes or threading through clothing. As one person commented, the joints aren't terribly strong, so care must be used until the assembly can be immobilized somehow.

[sdudley]

Try radioshack:

http://www.radioshack.com/product/index.jsp?productId=2036277

[michaelmacnz]

I think the "Magnet wire" is just the enamel coated single strand copper wire that is used to wind "Electro"magnets.. Yes? readily avail from your favorite radio store. Another good source is to recycle it from computer power supplies or small electric motors. Small mains electric motors have really fine wire.

[Mic100]

In French CMS Composants Montes en Surface, ( Montes is lake Mounted in English)
the site Instructables not know the French accents and the e de Montes need a one

[Mic100]

In French CMS Composants Montés en Surface