Schottky Diode with heat sink case and heat sink compound?

Discussion in 'General Electronics Chat' started by frank55, Jan 3, 2017.

  1. frank55

    Thread Starter Member

    Dec 6, 2013
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    Hi guys hope you all had a happy New Year ; i have here a project for a Phillips LCD power supply that is dead and i found one of the 2 Diodes SB260 that are in parallel short,this is a known fault on this modle #philips 46pfl5505d/f7,and i learned that i can make an adaptation to the circuit to improve circuit so it won't fail again ,instead of putting back the 2 diodes SB260, replace them with a TO-220 case with a heat sink . my question should i use silver light heat sink compound with the heat sink for better heat transfer of just attach the Vishay 8TQ100, Schottky Diode, 100V 8A, 2-Pin TO-220AC without heat sink compound? thanks



    http://www.mouser.com/search/ProductDetail.aspx?r=844-8TQ100PBF
     
  2. #12

    Expert

    Nov 30, 2010
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    I don't know why there is any question about using heat sink compound on a heat sink. It's not all that expensive, and it cuts the heat transfer resistance in half.
     
  3. frank55

    Thread Starter Member

    Dec 6, 2013
    288
    10
    Thanks #12, i have silver light compound for CPU's,so heat will pass to the heat sink case faster? remember the two legs of the diode Cathode is ground and the anode is positive the heat sink case will not be in contact with the chassis.
     
  4. #12

    Expert

    Nov 30, 2010
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    That's nice, but it has nothing to do with whether to use heat sink compound. If the case of the diode is going to be electrically connected to the heat sink, it will still be connected after you grease it. If you don't want it electrically connected, you can sometimes buy isolated tab TO-220's or use an insulator kit...and it still has nothing to do with heat sink compound unless the compound you have is electrically conductive.
     
  5. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
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    You ALWAYS want to use "thermal interface material" of some sort or another when attaching a device to a heatsink.. That may be an electrical isolating pad/material or may just be "grease/heat sink compound" of some sort..
    The surface of a heatsink and the chip are NEVER perfectly flat and will always have some sort of imperfections/dimples,etc... The interface material fills that gap and allows the heat to flow better than without..
     
    #12 likes this.
  6. frank55

    Thread Starter Member

    Dec 6, 2013
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    Thanks guys, you're Pro's
     
  7. bertus

    Administrator

    Apr 5, 2008
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