Vias size for heat transfer on copper pad on both layers

Discussion in 'General Electronics Chat' started by Vindhyachal Takniki, May 5, 2016.

  1. Vindhyachal Takniki

    Thread Starter Member

    Nov 3, 2014
    349
    6
    1. I have designed a circuit with 10A of current capacity. For large current I have made large copper track on both top & bottom layer. Now to connect both tracks, I have made multiple vias of size
    drill dia: 23.62205 mil
    pad dia: 39.37008 mil

    Vias are connected so that heat can be transferred between both tracks equally on top & bottom.
    A)What is the ideal vias size for this kind of purpose.
    B) I have found one chinese PCB, they have vias spread acorss track. What is size of vias in attached pics?

    2. I have attached gerbers EVM of bq24650. On top layer it has IC bq24650 with 9 micro vias benath it. What is tehre size. I think it is 0.010 inch as mentioned. Is it tht small?
    What is drill & pad size for this via?

    3. I have to design a heat sink for PCB. On locla market I have it just a Aluminium which has been tooled for this purpose. But on internet I was reading heat sink are of particular AL alloy. Does that mean I should get it tooled from some reputed manufacturer only?
    AL alloy have better thermal conductivity but do they have better thermal dissipation also?
     
  2. SLK001

    Well-Known Member

    Nov 29, 2011
    825
    229
    To carry 10 amps on an external trace requires a trace of only approx 150mils (0.150") with 2 0z copper. Of course, you could go higher in width.
    A 0.024" via can carry approx 3 amps, so you will need at least 4 to get from one side to the other. Bigger vias are better.

    There is no need for a parallel trace on both sides.
     
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