Hand wiring up smd led's

I found some hair thin wire and was able to get it working... actually the hardest part was getting the cathods all wired up using the 24 guage wire. Supprisingly the "hair wire" (I think it's like 40 gauge(about 3-5 mills thick) sticks pretty well.

Is there any way to remove the enamel coating quickly and easily? Right now I'm scraping it off but I need a better way.

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Have you considered ditching the discrete LED's and just go with fiber optic cable? That would seem to be a lot easier that the approach you are considering.

-mpm

Buy some wire with insulation that's designed to be burnt off by soldering temperatures. I think you need an 800F iron, not

If can be bare wire just strip off some ac line cord and separate out the strands...

Why wood and wires? Get a piece of copperclad FR4, score patterns with an X-acto knife, scrub hard with Scotchbrite, solder them down.

John

We have a winner. You can pick up a full color fiber optic "plant" thingy for 1$ that has RGB LEDs, a bunch of fiber and of course a chip driving the whole thing with different colors.

Well, it was just for testing... I'm not sure being burnt is a good idea as it might end up burning off too much? I actually need very little exposed area... probably less than 1 mm.. so it might work.

Because I said so... It's the application. Can I make a pcb 2mm thick that contains all the circuitry? In fact that would be the easiest way but I'd have to put 18 traces in 2 mm + the large ground wire + vias and it's not going to work. Although it does more descruction to the wood than I'd like it would definitely be easier to "install" and "replace".

No, it can't.

I actually ripped up an old guitar pic I had that uses, I guess, 40gauge wire and it works pretty well. Although maybe too small it actually solders to the led pretty easily and holds decently. The enamel is copper color so it's hard to tell if it's bare(actually almost impossible) but it seems to come off easy too. (although I'd rather have a chemical method)

Have you considered ditching the discrete LED's and just go with fiber optic cable? That would seem to be a lot easier that the approach you are considering.

-mpm

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I don't think this will work? Can fiber optic be let than 20 mils in diameter? (remember, because of the design I have to "stack" around 18 together.... my hole need to be small as possible. Not only that the fiber would need to make 90 degree bends. I'd still have to drive the fiber with RGB LED's to get the same effect? Hence they would have to exist somewhere else and just as many... so the fiber seems to be an aditional cost. Although if it solved the routing problem it might be worth it as one could just make a pcb with all the led's on it. I don't think though that it will work though because of the specific application. I don't have much experience with fiber optic though and maybe it is flexible and thin enough.

After playing around with it and the very thin wire I think it might work well. The biggest problem I'm coming up against right now is that the cathodes for all the led's are split so when I try to solder them all at once to the ground wire one usually end's up not making it.

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" Is there any way to remove the enamel coating quickly and easily? Right now I'm scraping it off but I need a better way."

I just burn it off with a small butane torch and then lightly sand before tinning. I've used chemical stripper in the past but it's nasty stuff. Methylene Choloride and such...

George Herold

FR4 is usually 0.062" (1.6mm) thick, but it's also available in 0.032" (0.8mm). If that's still too thick, why not apply copper tape directly to your wood. Then use an X-acto knife to make patterns as was suggested earlier? You could use the copper tape for your ground, or use paper thin brass or copper sheets from a hobby shop. I bought wide adhesive-backed copper tape at a garden center. It's sold to repel slugs (snails).

-Dave Pollum

" Is there any way to remove the enamel coating quickly and easily? Right now I'm scraping it off but I need a better way."

I just burn it off with a small butane torch and then lightly sand before tinning. I've used chemical stripper in the past but it's nasty stuff. Methylene Choloride and such... ====

I can't get the precision I need. If I used a torch I'd end up burning way to much off. I just need to get about 1mm or even less. These wires are hair thin... I think your thinking of a much larger gauge?

It's not thickness but width

it would be about 3mm x 3" x h

where h is the "thickness" you refer too.. it can be up to several mm but the smaller the better.

What part of "designed to be burnt off" don't you understand? There are at least two common types of insulation for this.

On Oct 15, 4:48=EF=BF=BDpm, "Jon Slaughter" wro= te:

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Labor costs will kill you on hand-assembly of whatever this is.

If fiber optic is out (why is that again?), how about using a membrane keypad / overlay with integrated LED's? Like these:

Anything done by hand will kill a project. ( other then a one off )

If this is a funded project, why not use a FLEX circuit.

A large panel can be created and can have as many rows as you want, then cut down with a pair of scissors.

And you can use standard PCB software.

donald

Hi Jon,

Looking at a Flex circuit for this looks pretty easy.

You said: >I need to run 6(or potentially just 3 if I have to) in series which gives >18+1 wires. Each led will consume max 25mA and therefor the ground must >carry 18*25 ~= 1/2 amp.

Does series mean all the red leds, all the green leds and all the blue leds in series with each other ?

And a common ground ??

Well thats 4 lines, right ?

To have 18+1 wires are parallel, right ?

If each led is driven separately, then any one trace will have 25mA, except ground as you stated.

I think this can help you:

Page 13 is what you need to look at.

I have not used this company.

donald

Page 14 says an 8 mil trace of 1 oz copper will carry .5 amp.

donald