Micro and Nano LED's

[kirkifer]

Yeah, that large qty. of LEDs is a great find... It does make one wonder... I might give them a try. It seems like I am going through these things learning the best way to install them. (some got heat damage and some just disappear... )

Here is what I have learned...

[glow=red,2,300]1)[/glow] Buy some good tools. I bought a $16.00 pair of micro tweezers and they are worth every penny I paid for them. I also bought a heat controllable solder iron. It can be done with a cheap iron, but is much easier with a better iron.

[glow=red,2,300]2)[/glow] Tin the wire and the pad first. The wire requires much more heat time than the LED pad...

3) When bonding the two together, USE NO MORE than 600 degrees and just touch the LED.



Now, here is the part I am still figuring out. Any input or correction of errors is what makes this board useful. So have at it:

The cathode and anode are hard for me to identify on these super small SMDs. It seems to me that the cathode (-) has a little more material on the back of the SMD.

The cathode (-) is connected to the function output and the anode (+) is connected to the resistor and then to the blue wire. BTW, I copied the idea of using the breadboard and soldering the resistors to the breadboard. That is an awesome idea and works well !!!

I have not yet figured out the best way to twist the #38 supply wire yet. It is not something that is easily held in a drill chuck. Any suggestions?

Finally, how do you identify the ends of each wire once you have a twisted pair to supply a light? This must be a function of a multi-meter to determine which ends complete a circuit. I apologize for any ignorance. This is the first time I have used wire this small and since it is not color coded it gets confusing quickly. Any specific techniques or hints are appreciated.

[railfanalex]

Well this company looks promising, I'd just like to get my hands on a few samples first to see if I like them before I dig in to get 1000 of them!

Now I have a question: The 0603's are much easier and cheaper to find than the 0402's, so do you guys think that with a bit more work it would still be possible to get the 0603's in a ditch light casting or is the 0402 the only one to fit the bill?

[kirkifer]

I think it depends on the casting used. I use the detail associates castings and mount the LED with thick CA on the "back" of the bezel. In other words, I do not cram it into the through hole. It will not fit. These things are bright and when they are on, people will ask how you got such a bright bulb in there...

Sorry, I do not have a camera capable of detail photos.

[markdeimling]

I just got mine in the mail today and I did not expect them to be so small. I wired one and was trying to figure a way to mount it in a model. I could not do it so I just used some fiber optic cable and a normal LED. I am thinking of changing out my Athearn RTR lights but need a good system of mounting them.

If anyone has some suggestions or pictures of how they mount them that would be great.

[kirkifer]

Hey Mark,

Hang on to them... I will try and take some pics and see if I can get them to turn out. If not, it will have to wait until I get one of those fancy DSLRs.

I agree with you, they are painfully small. It is interesting to note that some folks are using wheel mounted resistors that are the 0603 or the nano 0402 size because they think the 1206 size is too big and noticeable on their rolling stock.