Is this heatsink workable for COB LED ?

Discussion in 'General Electronics Chat' started by Rainbow Clouds, Feb 13, 2015.

  1. Rainbow Clouds

    Thread Starter New Member

    Jan 19, 2015

    I'm looking for a really small size heatsink for my project for COB or STARBOARD.
    I found this heatsink, and the dimension is really small and the Thermal Resistance is compatible to other bigger heatsinks, i'm not sure if i have misunderstood the datasheet and wish some advice & help of the application of this type of heatsink. Is this for SMD LED only ?

    Thank you!
  2. WBahn


    Mar 31, 2012
    It may be intended for LED modules, but you can use it on anything that you can get a good thermal mounting to.

    Since I have no idea what you mean by COB or STARBOARD, let alone what you are trying to do and what your needs are, I really can't say much more.
  3. Rainbow Clouds

    Thread Starter New Member

    Jan 19, 2015

    Thanks for your reply.
    Sorry i meant LED Chip On board, and LED starboard.
    I'm trying to make a lighting however i have limited space so im looking for a small heatsink.
    However comparing with the other heatsinks that i saw, this one is exceptionally small with the same thermal resistance so i couldn't comprehend how that is possible so i just want to double confirm of it's application.
  4. #12


    Nov 30, 2010
    Ohmite is a very good company. You can trust them.
    Rainbow Clouds likes this.
  5. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
    The thermal resistance of the heatsink is known..
    Now whats the stated thermal resistance (junction to sink) of your LED on starboard/COB?

    Assuming you use the first one with a thermal resistance of 9 degC/W and if your LED is a 3W version you know right now that its going to be 27degC over ambient for just the heatsink.. Now we need to add in the LED/starboard..
    Example... if your LED/package is 11 deg C/W (including thermal grease) then with 3W you are looking at 3 x 20 = 60degC over ambient.. So with a 25 deg ambient your LED junction would be running at 85degC.

    From memory I think typical 3W star boards are like 5deg C/W.. Plus 1degC/w for thermal grease.. now you just need the LED spec to add to that. (junction to case) and your question is answered
  6. RichardO

    Well-Known Member

    May 4, 2013
    Nice heat sink. I like all those beautiful fins!