4 Replies Latest reply on Dec 1, 2016 7:24 AM by Daniela Coblas

    Thermal resistance in K*m^2/W or material/thickness definition.. ?

    Daniela Coblas

      I am trying to model a TO-247 transistor on a heat sink.

       

      The data sheet gives :

      Thermal Resistance from Junction to Case 0.27 °C/W

      Thermal Resistance from Junction to Ambient 40 °C/W... and no other information about materials (case, chip, bonding material, thermal pad, connection pads).

       

      After searching a little bit on the internet I can make the following hypothesis :

      1. case - epoxy resin

      2. chip - SIC (4H-SiC, or 6H-Si-C)

      3. Thermal pad - cooper

      4. Connection pads -cooper

       

      For the bonding material I have no idea...so the only way to define it should be through a contact resistance between the case and the junction....

       

      If I choose to use material/thickness definition I have to approximate chip material&thickness.. so I do not know if it will be accurate.

       

      The problem is that I do not know how to convert the RTH junction to case given by the manufacturer data sheet (°C/W) and the Contact resistance required in SW Flow simulation which is in K*m^2/W ...

       

      Can anyone help me ?