What are Thermal Pads in PCBs?
When soldering PCBs with large copper planes with through hole and/or SMD components, there is a risk that heat and solder will “disappear” into the surrounding copper planes if the pads are connected directly. If thermal relief pads are not used, there is a real risk of poor quality solder joints. Fineline recommends the use of thermal relief pads to improve heat distribution. A typical thermal relief pad is shown below for PTH, similar spoked design should be used for SMD also.