Whats a good source for SMD LEDs?

[overedline]

I am looking to only buy a few, maybe 10 at the most. Its only for two rc helis of mine.

Also, another quick question: Are the ones found in the light strips that they sell at pep boys usable? I mean are they self-contained inside the strip or is the strip material the actual insulation for the diode? (if anyone knows).

Thanks

[jeffs555]

When I need a small quantity of only one part, I look on Ebay first. Often you can find the part with a low buy-it-now price that includes shipping and is lower than just the shipping cost from one of the electronic supply houses.

As for the LED strips, I think they are just normal surface mount LEDs mounted on a flexible strip with embedded conductors.

[earlwb]

Small quantities Ebay first.
But if you plan on ordering more than $25.00 worth of electronics stuff (maybe more now for the minimum) then Digikey is good. Or Mousers too.
The shipping costs is what gets you at Digikey or Mouser's . But ordering a bunch of parts and stuff bring the shipping costs more into line.

yeah the LEd strips are usually a semiflexible PC board and you can usually cut it off to length as desired. Normally the LEd strips are setup for 12vdc for cars. So to use then with say 5vdc, you'll need to change the small current limiting resistors out.

[Hell-e-Guy]

You can also do a search here:

http://www.dealextreme.com

Free shipping on all products.

You can even take apart from one of the products that has SMD LEDs.

Hell-e-Guy

[rich smith]

It is almost impossible to remove SMT LEDs without impacting brightness due to low thermal mass. In fact difficult to install them without damage.

[Hell-e-Guy]

Rich,

Didn't know that this could effect brightness? Good to know!
When I remove 2 terminal SMT devices I use 2 soldering irons and they remove with no problems.

Hell-e-Guy

[pldaniels]

You can also try places like Sure Electronics ( www.sureelectronics.com I think ).

Larger SMD leds around the 1206 size are fairly hardy (I use down to 0603, going to 0402 is just too painful), they're all specced to handle two reflows each of up to ~260'C, however I invariably just throw away any ones that I have to desolder for what ever reason.

If you want some more directional but very intense SMD's you can get the units with integrated lenses. I use these on several of the R/C products I mfg, very handy if you are trying to signal through a layer or two of FG or kevlar :)

Paul.

[rich smith]

If lucky it's not enough to notice but the photometer always showed decrease no matter what temp I set iron to or how fast it was done. Not always obvious to naked eye but far more than through hole. The girl at the factory (Shen Zhen) said very hard to get correct type of solder paste and timing is critical but even then some dimming is expected.

If I really screw up installation (too slow) it has to be replaced with a new one. They are always tested before soldering to eliminate infant mortality syndrome. Japanese parts are much better but cost 5x more.


Rich,

Didn't know that this could effect brightness? Good to know!
When I remove 2 terminal SMT devices I use 2 soldering irons and they remove with no problems.

Hell-e-Guy

[overedline]

Thanks for all the great info and sources. I'll be sure to solder them very quickly to avoid damage, and buy some extras just in case. Thanks a lot!

[earlwb]

What I do is use a little dab of liquid flux on the PCB, then I carefully pace the SMD LED on the pads and use a dull X-acto knife blade to position and push down lightly to hold the led in place. Then I give it a quick touch with the soldering iron for a split second on each side. It doesn't take much. Usually you can tell, the little buggers sort of melt almost instantly if you hold the soldering iron on them for that tiny bit too long.
Yeah I have used the 402 sizes and they are tricky for sure. Like trying to solder salt and pepper on the PCB's.
I wouldn't go under 603 size unless you have to.

[pldaniels]

Earl,

I just reflow them these days in my modified pizza oven... a lot easier :\ That said, 0402 is definitely no-go for polarized bits, I'll do resistors and ceramics to that size but not diodes/leds/etc :eek:

Paul.

[rich smith]

You can also try places like Sure Electronics ( www.sureelectronics.com I think ).


They only sell power resistors. Maybe confused them with Sure guy on Ebay who does sell LEDs but not the tiny ones.

PS with my Harbor Freight jewellers loupe glued to dollar store glasses 0402 LEDs are easy. The trick is to use a big (chisel tip) iron not a wimpy pointy one.

[earlwb]

pldaniels.
yeah I have done the reflow method using a small roaster broiler oven too.
I always like watching through the glass window as the parts self align just as the solder melts. For some odd reason i find that fascinating.