N 2010-03
r 2009
Application Note AN 2010-08
V2.0, August 2010
6
Mounting the Module to the Heat Sink
The clamping force of the module resulting from the assembly process to the heat sink
depends on the torque applied and the condition of the heat sink material. The following
torque values specified in the datasheet result from steel screws in aluminium heat sinks with
a dry M6 thread and their typical friction factors of µ
G
=0.2~0.25 (µ
G
=friction coefficient thread
in heat sink):
M
min
=3Nm to M
max
=6Nm.
For a good thermal contact to the heat sink the following procedure is recommended when
tightening the eight M6 fastening screws with washer (according to DIN 433) and spring
washer (according to DIN 127).
1. Place the module onto the heat sink and fix with two screws.
2. Fix the screws with 0.5Nm (hand tight crosswise) in the sequence showed in Figure 9.
3. Tighten the screws with 3Nm – 6Nm in the same sequence (crosswise)
Figure 9
Tightening sequence to mount the module.
