Application Note
21
<Revision 2.4>
<<2019-06-17>>
Assembly Instructions for the Easy-PressFIT Modules
10
System considerations
If the module is correctly mounted to the heat sink and to the PCB, the screw clamps will apply the necessary
pressure. This pressure, together with the correct amount of thermal grease, will ensure a low thermal
resistance and an optimal thermal flow between the module and the heat sink. Since the PCB is connected to
the module by pressed-in pins only, suitable measures have to be taken to ensure that vibrations are kept at a
minimum. Any possible movement between the terminals and the module case has to be avoided. Each single
pin may only be subjected to a maximum press and pull force of 6 N vertical to the heat sink. The overall pulling
force to the module of 20 N must not be exceeded. The compressive force could be 10 times higher than the
possible pulling force. A low compressive load to the module is preferred. Therefore, the circuit board should
additionally be fixed to the heat sink at a position close to the module. Two options are possible:
Figure 19
Fixing the PCB
10.1
Module is already pressed into the PCB before mounting
To minimize the forces that are applied to the pins of a module, it is recommended to keep a distance of at
least x = 5 cm from the module’s outer edges (Figure 19).
10.2
Module is pressed into the PCB after mounting
In this case, no mechanical stress will occur. Therefore it is allowed to place the distance keeper as close as
possible x ≤ 5 cm to the module.
