Heat Sinks for DC Fast Charger Power Modules

Requirement

The customer’s DC fast chargers run power modules inside a closed cabinet. Adding a dust filter raised airflow resistance, and their previous sink had wide fin pitch and a thin base, so modules derated under high load. They needed more cooling in the same space, with unchanged module mounting holes.

Our approach

We thickened the base and moved to a dense skived structure with tighter pitch and taller fins, aligned to cabinet airflow. The mounting face is milled and flatness-corrected to keep contact area. Holes are machined from the module datum in one setup so assembly stress stays low, and a side pocket is left for the temperature probe.

Delivery and inspection

Three pitch variants for airflow and temperature comparison, then production with flatness and critical dimension sampling.

Project summary

Module temperature dropped under the same conditions and derating stopped at full load; the airflow penalty from the dust filter was offset by the new fin geometry. The design carried over to the customer’s second charger platform.