TN1037 Datasheet, PDF (10/24 Pages) STMicroelectronics – nano mounting instructions and heatsink

Cooling techniques and heatsink mounting proposals
Figure 10. Large heatsink pasted on the package
TN1037
In order to ensure safe working conditions, as previously stated in Section 1.3: Safe
distances, the adhesive foil or the thermal rubber must be placed to improve electrical
isolation and therefore must be properly sized in order to increase the creepage and
clearance distances.
2.3
Heatsink bonded on the PCB by mounting screws
The heatsink can be also bonded on the package and fixed on the PCB using one or two
mounting screws (Figure 11), ensuring a firmer assembly process. The use of this heatsink
with dedicated form factor prevents any possible stress on the leads of SLLIMM-nano and
the PCB soldering pads. This technique requires the use of a thermal pad between the
heatsink and the topside of the SLLIMM-nano in order to ensure the creepage distance. A
safe distance between the shorter side of the device (where some trimmed terminations are
placed) and the heatsink must be guaranteed in order to ensure clearance. The two screws
option is preferred in order to improve mechanical stability and reliability of the system. Any
mismatch in thickness between the SLLIMM-nano and the heatsink can be resolved by
using a thin insulated spacer between the device and the PCB.
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