6 Summary

Layout is essential to optimize the thermal performance of a high-density buck converter. Thermal vias play a significant role in vertical heat dissipation and they must be placed directly below or very close to the heating elements/components. Additionally, the effective thermal resistance of parallel vias in an array is much less than that for a single via. Hence a number of vias can be closely spaced for better heat dissipation.

If the component density is not too high on the PCB, through-hole micro vias would be sufficient to dissipate heat on the PCB. Blind vias are normally used in HDI PCBs where component density is too high and when multiple traces are present in the inner PCB layers which cannot be cut-through. Therefore, by using simple through-hole micro vias, we can achieve a performance and cost optimized solution.