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Application Note
49 of 53
V 1.0
2019-04-01
IM393 Application note
IM393 IPM Technical Description
Heat sink mounting and handling guidelines
Figure 41
Recommended screw tightening order
8.2
Handling guideline
When installing a module to a heat sink, excessive uneven tightening force might apply stress to inside chips,
which will lead damage to the device. An example of a recommended fastening order is shown in Figure 41.
•
Do not over-torque when mounting the screws. Excessive mounting torque may cause damage to the module
holes, screws and heat sink.
•
Avoid one-side tightening stress. Uneven mounting can cause the module hole to be damaged.
To get effective heat dissipation, it is necessary to enlarge the contact area as much as possible, which will
minimize the contact thermal resistance.
Apply thermal conductive grease properly over the contact surface between the module and the heat sink,
which is also useful for preventing the contact surface from corrosion. Furthermore, the grease should be of
robust quality and long-term endurance within a wide operating temperature range. Use a torque wrench to
tighten to the specified torque rating. Exceeding the maximum torque limitation might cause a module to be
damaged or deteriorated. Ensure that any dirt remaining on the contact surface between the module and the
heat sink is removed. All equipment used to handle or mount the IM393-XX inverter IPM must comply with the
relevant ESD standards. This includes, e.g., transportation, storage and assembly. The module itself is an ESD-
sensitive device. It might therefore be damaged in the event of ESD shocks. Do not shake or grasp only the heat
sink; in particular, avoid any chock to the PCB by grasping only the heat sink. This could cause package
cracking or breaking.