Copper is a superb thermal and electric conductor. Thick copper layers increase heat transfer along and throughout the PCB. With the rigorous specifications for higher precision in PCB fabrication process, line width and spacing have down below 0.1mm. Gold-plating board is simpler to make short circuit than immersion gold board. https://solarenergystoragelifepo439372.blogscribble.com/31057037/the-2-minute-rule-for-pcb-board-for-vehicle-control-panel