Heat sink or heat exchanger is a passive cooling device used in electronic components to prolong their longevity, performance and reliability. All electronic components utilize current for the operational purposes and thus become prone to sharp increase in the temperature. The generated heat above the operating level becomes critical in-terms of failure component and hence, appropriate thermal management demands come into act. Finned or extended surface heat sinks are used to cool power electronic devices and components. The comparative results of plate-fin forms on the thermal performance of the heat-sink with inline arrangement is analyzed in this paper. Four forms of fins: Rectangular, One-side tapered, Inverted T section and I section with and without honeycomb perforations are designed on SOLIDWORKS® and analysed using ANSYS® software to identify a cooling solution for a CPU in terms of temperature and directional heat flux along x, y and z directions. The aluminium alloy 6063-T6 and natural graphite are selected as a base plate and fin materials respectively. The main objective of this paper is to contribute to this improving area of research by studying the effect of honeycomb perforations of plate fin heat sinks under natural convection using steady state thermal analysis at a constant heat flow of 20W and 40W in two different cases with air inlet temperature taken as 37.85° C. A total of 16 specimen were analysed. 8 specimen of plate fin heat sinks without perforations were compared with the rest 8 specimen with honeycomb perforations. It was evaluated from both the cases that inverted T sectional fin with perforations provided an improvement in thermal efficiency and better heat flux removal results among other plate fin profiles where as in terms of density and cost trade-offs one side perforated tapered fin outperformed other fins.