Soldering Surface Mount LEDs

NOT BAD FOR NOT HAVING SOLDERED IN 8 YEARS! :)

I've been working on soldering some surface mount (SMD) LEDs. These LEDs are 1/8" long and a 1/16" wide. I attached these crimping beads that I found at a beading store and I used a fine clean tip with a high gauge solder wire. I think I got some good results. The LED next to quarter (near the a in "Dollar" doesn't have any crimping beads soldered onto it - just to give you an idea about how small I'm working here.

The long leads were an experiment for another small wall piece that I am working on. The LEDs aren't exposed here, just the leads with the crimps attached.

HERE IS A GREAT TIP (One that Ian Hanschen came up with): place the the components face down on a piece of tape and nest the beads next to them. The tape holds the beads in place while you solder them. Also you can tin the bead and gently roll it over to the LED or a lead (Leah Buechley method).

Hat

I am moving at a snails pace on the hat...but I am making progress. :) I may leave the circuitry exposed as I am really enjoying the components and stitching exposed.

Bracelet

Here is a bracelet that I knocked out in a few days. All of the stitching is done with conductive thread. The LEDs I found at Vetco in their 100 LEDs for $5 bin. Their old and boxy, so they make really interesting objects in of themselves. I was originally going to cover the bracelet with another layer of felt to cover the circuitry and the resistors, but I'm enjoying the way it looks exposed, so I'll just leave it that way.

Notes from the Lab 9/08 - Conductive Epoxy

I decided to use conductive epoxy on the connections between my "traces" and connections between traces and components on the hat project. I applied a little dabble in these places on one side of the hat, and I had fantastic results.

Unfortunately, when I applied it to the other side of the hat, I lost parts of my circuit. Yikes! What's happening? I am investigating the situation more. In fact, I've ripped out all of the circuitry on that side of the hat and I am now getting ready to sew it all back on by hand.

TEXTILES AND ELECTRONICS LINKS

Vincent Leclerc with XS LABS

Be sure to check out the SKORPIONS project on this page!

MIT Media's lab on wearables.

Leah Buechley
Leah Buechley is a researcher that studies soft circuits specifically. She has tons of info for all experience and level types (novice to hacker) plus lots of good links for materials and kits.

SparkLab

Fashioning Technology

The work of Anouk Wipprecht

Fashion designer and artist Hussein Chalayan.

Joo Yoon Paek

New Brave World - Hybrid Scrapyard

XY Interaction. This is really an EXCITING project involving sensors, electronics, etextiles and music. CHECK THIS OUT - IT IS A MUST.

Lucy McRae is doing some "wow" circuits as well.

Rebecca Horn works with electronics and has been for some time. Her early work uses the body as a point of departure.

Lady Ada is a great Hacker. She works with everything and has great resources and kits for everyone.

CONDUCTIVE EPOXY

I am trying conductive epoxy to seal some of my connections on my circuits. It is QUITE gooey and expensive. These two tubes, which came together, we about $32. I think you can get if for cheaper, if you shop around.

It is a cold solder that is made of silver and resins. The blob closest to the ruler is about 3/8" wide and about 1/16th of inch thick. It has a resistance of about 10 ohms. It takes about 3 hours for it to dry solid.

Notes from the Lab 8/08

Currently I am working on a project where I have been sewing a circuit into a hat (which is the style of the old aviator hats). It has a felt outer shell and an inner lining made of linen. My intention for this project was to have the circuitry covered by the felt layer and all of the circuits sewn into the linen layer, with the LEDs popping out into the felt layer. Felt is a great fabric to work with because you can make holes in it and it will not fray.

Ian Hanschen drafted out this circuit using the software Circuit Wizard, which is a great way to run a simulation of a circuit if you don't feel like setting it up on a bread board. The circuit is a LED flasher with 8 LEDs. 4 flash on one side of the hat and the other 4 flash on the other side.

I sewed the traces using my sewing machine (with conductive thread in the bobbin) and attached all of the components by hand. What I have discovered is that conductive thread actually contains a great deal of resistance. I am measuring about 80 ohms for every 10 inches of thread.

Here is the originally sewn hat with all of the traces sewn on with a machine.




This will definitley impact how many ohms my resistors may have to be and how long I run my "traces".

When the thread is sewn by hand, I double the thread, creating a bundle, which decreases my resistance by half. I began replacing the traces I had sewn hand stitched lines.



The other issue I seam to be running into is when the hat lays flat the circuit seems to work, but when it flexes, I loose connections. I believe this is because the connections between the thread and the components are not strong enough. Each time the hat is flexed the joint between the components and thread is articulating too much, causing it to short. I've also noticed that when I bring 2 traces together, I am also not making good contacts. Below is an example.


Back in the lab...shooting trouble, until I remedy these issues.

Later...