How do I insulate high power LEDs from my MCPCB?
How do I insulate high power LEDs from my MCPCB?
(OP)
I should even call it a PCB, it's just a bar of aluminum really. I need to put down a dozen or so 3w leds and I'd like to set them on to the bar directly. Is there a non-conductive thermal tape I can use? There is some continuity between one of the pins and the base, so I need to separate it somehow.





RE: How do I insulate high power LEDs from my MCPCB?
http://www.bergquistcompany.com/
They have it all. Not cheap so if you are doing production then you might want to look to other places like Panasonic and 3M.
If you are talking about LEDs mounted on STAR boards then you have something wrong because you can certainly mount all of them onto a conductive heatsink.
Keith Cress
kcress - http://www.flaminsystems.com
RE: How do I insulate high power LEDs from my MCPCB?
RE: How do I insulate high power LEDs from my MCPCB?
I have used this one from 3M to good effect in the past:
http://multimedia.3m.com/mws/media/122119O/3m-ther...
Dan - Owner
http://www.Hi-TecDesigns.com
RE: How do I insulate high power LEDs from my MCPCB?
I've even used 2 part thermal "adhesive" (Arctic Silver) and didn't do anything to mechanically secure them before (no screws,etc..)
http://www.coolerguys.com/840556003083.html?produc...
RE: How do I insulate high power LEDs from my MCPCB?
RE: How do I insulate high power LEDs from my MCPCB?
post the datasheet for the LEDs so we are clear exactly what you have....
Why do you think you need to pack them closer together?
And a "bar" of aluminum is a poor "heatsink".. Surface area is king...
"packing" high power LEDs together on a poor heatsink is just asking for trouble..
RE: How do I insulate high power LEDs from my MCPCB?
Photo attached (although as mentioned, to get them closer together, I'm using a 6 pin setup sans star heat sinks, so I can wire them in series as close together as possible)
Datasheet:
https://solarbotics.com/product/led-rgb-star43cd/
So the end result would ideally be very tightly packed leds run in series, running at minimum power, on an aluminum heat sink. To complete the test though I need to find something a little thinner than the epoxy I'm using (barely shown on another test in the corner of the picture).
RE: How do I insulate high power LEDs from my MCPCB?
And your not running them at the lowest possible voltage.. LEDs brightness is dictated by current through them.
I hope you know that (LEDs) need to be fed a constant current (resistor or other current limiting circuitry) and not from a fixed voltage source.
RE: How do I insulate high power LEDs from my MCPCB?
Not a light saber! I've never even seen a Star Wars :)
RE: How do I insulate high power LEDs from my MCPCB?
Z
RE: How do I insulate high power LEDs from my MCPCB?
RE: How do I insulate high power LEDs from my MCPCB?
You can get cheap metal clad PCBs made to your specs on ebay,etc.. for a prototype.. sitopway does it
http://stores.ebay.com/sitopway
not sure the intention of your "prototype" is going to be..
as far as thermal/insulating pads,etc.. check out products from bergquist they have the thermally conductive/insulating products you need
http://www.bergquistcompany.com/ (sold at digikey,etc...)
RE: How do I insulate high power LEDs from my MCPCB?
I'll look into the thermal pads, thanks for the links.
RE: How do I insulate high power LEDs from my MCPCB?
Keith Cress
kcress - http://www.flaminsystems.com
RE: How do I insulate high power LEDs from my MCPCB?
Keith Cress
kcress - http://www.flaminsystems.com
RE: How do I insulate high power LEDs from my MCPCB?
I think the ideal epoxy replacement would be a liquid pour/spray thermally conductive, electrically non-conductive layer, that I fix these LEDs onto.
Thoughts?
RE: How do I insulate high power LEDs from my MCPCB?
http://www.amazon.com/MG-Chemicals-Thermally-Condu...
RE: How do I insulate high power LEDs from my MCPCB?
If you are concerned about a tape that has some surface adhesive still exposed then just cut the shapes you need. If you're just prototyping about, sit down with some scissors and get to work using the Bond-Ply 400 or one of the nice fully characterized 3M tapes MacGyverS2000 linked at you. Cutting little circles out of tape is much much easier than mixing liquids and transferring them here and there in an orderly successful manner with time ticking. Tape is considerably less wasteful ecologically if that matters to you.
If you can't bring yourself to using a scissors use an appropriate washer and and Exacto knife. If you don't want to do that find a piece of pipe with an inside diameter the same as your LEDs and then grind the outside diameter down to make a knife edge of the inside diameter. Using a piece of scrap wood you can punch out dozens of pads just the size you need. Using a pad that works instantly whenever you need them and doesn't take a day to cure, and drip, and run, all over, is way nicer to work with.
Keith Cress
kcress - http://www.flaminsystems.com
RE: How do I insulate high power LEDs from my MCPCB?
Thanks again! This really clarified the best solution.