Pre-wired SMD LED’s

[Dwight in Toronto]

Hmmmm … “does not ship to Canada”.

What the heck - “Canadian hobbyists matter”!

[peteski]

I always use SMD in my search string on eBay.  Something like "smd 0201 white led".
I just executed that search and I got 8 hits at the top of the search results.  Similar listings,but different color temperatures:
https://www.ebay.com/itm/255084670796
https://www.ebay.com/itm/265260151511
https://www.ebay.com/itm/353002158648
https://www.ebay.com/itm/353002160538
https://www.ebay.com/itm/334188312503
Then there are few automotive LED hits, then 2 more "good" hits:
https://www.ebay.com/itm/393494357771
https://www.ebay.com/itm/393494343175
Then few more automotive LEDs

[trainforfun]

I bought some prewired SMD from a China place , they are very , very small , don't know the size , sorry , the wires are so small , not hair but small , I tried to skin them , they just break , heated them with a soldering iron , nah , tried with an exacto to rub them , they break ....

Any great idea ?
I could use them as is because the last 1/8" is already skinned and the wires are like 3" long but ....

[MK]

How about a non-contact try with a solvent like acetone?  (Assuming it's your traditional lacquer coated magnet wire.)

[wvgca]

a little bit of heat always works .. use the tip of the soldering iron ...
by the way, i usually got 8.50 [canadian] for nine pre wired smd leds on ebay,
back when i used to make them

[peteski]

I bought some prewired SMD from a China place , they are very , very small , don't know the size , sorry , the wires are so small , not hair but small , I tried to skin them , they just break , heated them with a soldering iron , nah , tried with an exacto to rub them , they break ....

Any great idea ?
I could use them as is because the last 1/8" is already skinned and the wires are like 3" long but ....

Louis,
Is it a solid (not stranded) wire with enamel insulation (aka."magnet wire").

If yes, then the enamel insulation can be removed with heat from the soldering iron, but just touching the wire with the iron's tip will nto work. There is a technique for stripping the enamel.

I assume that you have a pencil-type iron (not one of those soldering guns). Often the iron has to be dialed up to around 800 deg. F to be able to strip the enamel. If you have a non adjustable iron, it will probably be hot enough by default.  The iron's tip to be clean and tinned.  Moist sponge works really well for wiping the tip clean.

Apply more solder to the tip to create a bulge of liquid solder.  Next dip the end of the wire to be stripped into some paste flux.  If you have liquid flux, it will not work as well, since not enough of the flux will remain on the wire.  If you have no flux - get some paste flux!   

Now push the end of the fluxed wire into the liquid solder bulge.  You have to plunge it into the solder (like you were stabbing an apple with a knife). Hold it in the solder for a second or two and pull it out, Now the part of the wire which was plunged into solder should be stripped and tinned - ready to use.

This method works for me pretty much all the time.

[jdcolombo]

What Peteski said, although I don't use paste flux on my magnet wire.  Just get a blob of solder on the tip, plunge the tip of the wire into the blob, wait 2 seconds, done.  I have 36-gauge magnet wire I use for my 603 LEDs, and this technique has always worked for me.

John C.

[peteski]

What Peteski said, although I don't use paste flux on my magnet wire.  Just get a blob of solder on the tip, plunge the tip of the wire into the blob, wait 2 seconds, done.  I have 36-gauge magnet wire I use for my 603 LEDs, and this technique has always worked for me.

John C.

When I don't use flux the solder does not want to envelop the wire. Kind of like poking a finger into a balloon. The flux seems to reduce the surface tension of the solder. Give flux (any viscosity) a try and let me know what you think.

[mmagliaro]

Another vote for plunging the magnet wire into a solder blob on the end of the iron.   If the wire is long enough and accessible enough, I find it also helps if you can give the end a quick scratch with an Xacto blade (holding the wire flat on a piece of wood or cutting mat).  Lightly skinning that enamel really helps the solder bond to the wire while the rest of the enamel melts off around it.

[mrp]

I tried some of these:

https://www.ebay.com/itm/255084670796

but they have a blue tint to them. Not warm white as listed.

Michael Pennie

[peteski]

I tried some of these:

https://www.ebay.com/itm/255084670796

but they have a blue tint to them. Not warm white as listed.

Michael Pennie

Most white LEDs actually use blue LED die which is encased in resin case that contains a phosphor which emits yellowish ligth when excited by the blue light from the LED.  The combination of some of the blue light from the LED die and the yellow light from the phosphor appears like white ligth to the human eye.

The problem with very small SMD LEDs like 0402 or 0201 is that the resin case containg the phosphor is very thin, allowing (especially on the sides of the LED) too much blue light to shine through, making the white ligth look blue (cold).  Only way I know to fix that is to to paint the LED with a transparent orange paint.  That will filter out more of the blue ligth, "warming"up the color.

I created a mixture which works best for me.  If I apply too much and the light looks too orange, I just remove the paint with some alcohol, and try to reapply it in thinner layer.  Make sure to cover the top and the sides of the LED.  I use a Microbrush applicator.

[trainforfun]

Louis,
Is it a solid (not stranded) wire with enamel insulation (aka."magnet wire").

If yes, then the enamel insulation can be removed with heat from the soldering iron, but just touching the wire with the iron's tip will nto work. There is a technique for stripping the enamel.

I assume that you have a pencil-type iron (not one of those soldering guns). Often the iron has to be dialed up to around 800 deg. F to be able to strip the enamel. If you have a non adjustable iron, it will probably be hot enough by default.  The iron's tip to be clean and tinned.  Moist sponge works really well for wiping the tip clean.

Apply more solder to the tip to create a bulge of liquid solder.  Next dip the end of the wire to be stripped into some paste flux.  If you have liquid flux, it will not work as well, since not enough of the flux will remain on the wire.  If you have no flux - get some paste flux!   

Now push the end of the fluxed wire into the liquid solder bulge.  You have to plunge it into the solder (like you were stabbing an apple with a knife). Hold it in the solder for a second or two and pull it out, Now the part of the wire which was plunged into solder should be stripped and tinned - ready to use.

This method works for me pretty much all the time.

Thanks Pete ,
mine are solid wire , with plastic insulation , but it's like glued to the very tiny wire , when I tried to stripped it , the wire just broke ...
I tried to heat it , does not work ...

[peteski]

So even the heat from a soldering iron does not seem to melt or burn the insulation?  It is possible that the insulation is made from Teflon.

[trainforfun]

So even the heat from a soldering iron does not seem to melt or burn the insulation?  It is possible that the insulation is made from Teflon.

Hi Peter ,
sorry it took me so long , I just tried with a soldering iron ( Weller , like a gun ) without any success , with a match it works but the wire is very easily breakable after , but it works !

[MetroRedLine]

I bought a magnet-wired SMD LED (from Evan Designs - they had some in the exact size I wanted) for a DCC installation and I heard one can burn off the insulation with a flame. So I did that and burned down my house.

I kid, I kid. Seriously, it didn't work, and I blew out that match ASAP before I wouldn't be able to be kidding. I just scraped away the insulation from the ends of each wire with an Xacto and when I saw the shiny metal wire exposed, it was ready for soldering.