High TG PCB refers to a type of specialized PCB designed for high-temperature applications. “TG” stands for Glass Transition Temperature, which is the temperature at which a material changes from a hard, glassy state to a rubbery, more flexible state. High TG PCBs are made from materials with a higher glass transition temperature than standard PCBs, typically around 170°C or higher. This allows them to withstand high temperatures and maintain their mechanical and electrical properties, making them suitable for applications where the PCB is exposed to high temperatures, such as in automotive electronics, computer servers, and aerospace systems.