The LMG365xR025 is a lateral device grown on a Si substrate. The thermal pad connects to the source of device electrically and thermally. In applications with high power dissipation, cooling using just the PCB may not be sufficient to keep the part at a reasonable temperature. To improve the thermal dissipation of the part, TI recommends connecting a heat sink to the back of the PCB to extract additional heat. Using power planes, thicker copper layers, and numerous thermal vias, the heat dissipated in the LMG365xR025 can spread out in the PCB and effectively pass to the other side of the PCB. By connecting the top copper layer with the bottom layer, thermal vias allow heat flow to bypass the low-thermal-conducting FR4 layers. Therefore, the overall effective thermal conductivity of the PCB improves. Thermal vias are normally formed by mechanical drilling. Because air is a poor thermal conductor, a plated copper layer on the via inner surface is recommended to conduct heat vertically through the PCB. For better thermal performance, use higher via plating thickness. To further improve the effect of thermal vias, fill the air gap with high thermal conductive epoxy or copper. Also cap the vias located in the footprint of the device. Without capping, solder from the pad leak into the via causing solder voids under the device. Apply a heat sink to bare areas on the back of the PCB using an thermal interface material (TIM). Remove the solder mask from the back of the board underneath the heat sink for more effective heat removal.