Weird Chinese COB LED Footprint

[amiljkovic]

Hi guys,

I’m looking for some info regarding the high-power LED from the attached photo bellow. I can’t find which package it is anywhere. Any info about it or if someone has the footprint and 3D model of it?

Also, as I only see it on Chinese sites like AliExpress, should I just avoid using it? They offer also pretty interesting lenses for it so that’s why I’d like to go with this particular package. Anyone with experience using these LEDs?

Thank a lot

[RaptorUK]

@amiljkovic

I’m looking for some info regarding the high-power LED from the attached photo bellow.

Perhaps you didn’t realise but this forum is about KiCad . . . where people come to get help using KiCad.

What is your KiCad question ?

[dsa-t]

Check out the LED_SMD:LED_1W_3W_R8 footprint.

[BobZ]

I do think the question of footprints ought to be a fair one on this KiCad Forum.

1. As for buying components from Ali Express; I have never done that. My guess is that there is some good and some bad so there is risk. I built what I call a dimlight in our laundry room using four 1W LEDs from (I think it was Marlin P Jones in USA) and that has been working for several years. But I am only running these LEDs at about 5% of rating. I did not use a pcb but I soldered the center circle to a “finger” cut from sheet copper and I wired to the other terminals.

2. As for the footprint; well that is part of the fun of laying out pcbs. I mostly use my own footprints anyway. In my LEDs the center circle is not electrically connected but serves as a heat sink point. So for use at significant power on a pcb, I think that center circle needs to be soldered to a copper shape which has significant area, or is connected through many vias to a copper shape with significant area.

I could design something here and now, but why don’t you try something and post it and I or someone else ought to render an opinion on whether it might work.

I do not recommend running the LED at full rated power.

[dsa-t]

@BobZ

As for the footprint; well that is part of the fun of laying out pcbs. I mostly use my own footprints anyway. In my LEDs the center circle is not electrically connected but serves as a heat sink point. So for use at significant power on a pcb, I think that center circle needs to be soldered to a copper shape which has significant area, or is connected through many vias to a copper shape with significant area.

Make sure not to connect all the heatsink pads to a single copper plane if you’re connecting the LEDs in series because they may/will break down due to excessive voltage.

[BobZ]

@dsa-t

Actually in these LEDs, the heatsink pad is usually sometimes electrically connected, so make sure not to connect all the heatsink pads to a single copper plane (at least that’s my experience).

That sounds good.

In my situation I did not make a pcb. I was able to check the connections before I kluged everything together. I believe that my assembly would not have worked as built if the center circles were not electrically floating.