Heatsink for Bridge Rectifiers D25XB60

Discussion in 'General Electronics Chat' started by abuhafss, Oct 13, 2014.

  1. abuhafss

    Thread Starter Active Member

    Aug 17, 2010
    141
    2
    I need to use two bridge rectifiers D25XB60 in a project, which are to be attached to a heatsink. The problem is that I do not have enough space to accommodate both of them side by side. I am considering to install one unit over the other as shown in the diagram. Which of these approaches be more better?

    Shall highly appreciate valued comments.
    Bridge.png
     
  2. MaxHeadRoom

    Expert

    Jul 18, 2013
    10,520
    2,369
    Can you not add to the top diag by placing aluminum H.S. on the very top also?
    Max.
     
  3. alfacliff

    Well-Known Member

    Dec 13, 2013
    2,449
    428
    the metal on the back of the case muxt contact the heatsink. how can you do that when stacking two packages? the thermal resistance for the top one will be high.
     
  4. abuhafss

    Thread Starter Active Member

    Aug 17, 2010
    141
    2
    No, the PCB will be on the top.
     
  5. abuhafss

    Thread Starter Active Member

    Aug 17, 2010
    141
    2
    There is no metallic back in this device. All is plastic.
     
  6. Papabravo

    Expert

    Feb 24, 2006
    10,138
    1,787
    Since they are thru hole components you should mount them vertically. This has the advantage of adding convection to the cooling mechanism.
     
  7. abuhafss

    Thread Starter Active Member

    Aug 17, 2010
    141
    2
    After soldering on the PCB, they will be bent and attached to a bulky heatsink.
     
  8. Papabravo

    Expert

    Feb 24, 2006
    10,138
    1,787
    With components like this one and 3 dimensions to work in there is no reason why they have to be bent over to attach to the heatsink. Why can't they be attached to a heatsink that does not even touch the board. Give us a mechanical drawing of the board and heatsink.
     
  9. MrChips

    Moderator

    Oct 2, 2009
    12,435
    3,360
    Neither approaches is a good idea.

    You want each device to be in contact with the heat sink.

    Then you need to double the size of the heat sink.
     
  10. BillB3857

    Senior Member

    Feb 28, 2009
    2,400
    348
    What about one on one side and the other on the other side having the full flat of each up against the heat sink?
     
  11. abuhafss

    Thread Starter Active Member

    Aug 17, 2010
    141
    2
    Actually, these are to be enclosed in an aluminum housing which will also act as heatsink.

    IMG_20141001_213357.jpg

    The final position would be something like this:
    B/Rectifiers attached at the bottom with pins pulled up and soldered on the PCB.
    And the whole set-up would be sealed in that aluminum housing using epoxy glue.
     
    Last edited: Oct 13, 2014
  12. abuhafss

    Thread Starter Active Member

    Aug 17, 2010
    141
    2
    So, I think there is no solution. I should make adjustments in the PCB.

    Another related question please:
    The same project include TO-220 devices which also require heatsink. I shall be using common heatsink with mica insulator and h/s paste. Where the h/s paste should be applied?

    a) between the heatsink and the mica insulator
    b) between the device and the mica insulator
    c) or both
     
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