Application Note
15
<Revision 2.4>
<<2019-06-17>>
Assembly Instructions for the Easy-PressFIT Modules
7
Condition of the heat sink for module assembly
The power loss occurring in the module has to be dissipated via heat sink in order not to exceed the maximum
permissible temperature T
vjop
specified in the datasheets during operation.
The condition of the heat sink surface in the area where the module is mounted is of great importance, as this
interface between heat sink and module is of decisive influence on the heat transfer of the entire system.
The contact surfaces, the surface below the module and the surface of the heat sink have to be free of
degradation and contamination to prevent excess mechanical stress to the module as well as an increase in
thermal resistance.
Heat sink requirements:
Roughness: ≤ 10 µm
Flatness based on a length of 100 mm: ≤ 50 µm
Note 1: The flatness of the heat sink should not exceed the values listed above. This area includes the entire
module mounting area as well as that of the clamps.
Note 2: If the layer of thermal grease applied is too thick, e.g. as a consequence of cavities, the thermal
resistance R
th
between module and heat sink will increase.
