This paper focuses on a development of a heat sink with slender square fins for the application of relay circuit cooling wherein the device shall be used to cool inline snatch relays that are used as circuit breakers in PLC boards. The geometrical layout and thermal analysis of the heat sink are discussed in this paper. The relay circuits need effective heat sinks in order to dissipate the hot side heat from the chip to the atmosphere. This encourages designing a heat sink in which heat transfer enhancement is carried out by designing of slender square fins with plain and skewed profile fins that have a three-layer concentric triangular layout. With this geometrical layout, the thermal analysis and heat transfer enhancement from plain and skewed profile fins configuration are carried out. Thus the study is focused on design development and testing of the heat sink with slender square fins that have a generic progressive transverse layout of fins. The surface area enhancement and cross flow heat dissipation is planned through the use of through skew in the direction normal to of air flow. The geometrical layout and thermal analysis of these fins are discussed in the paper. Fins to dissipate approximately 35 to 40 watt of energy to get a desired to bring about the cooling of the relay circuits.