Impact of Half-ounce Copper Foil Impact on PCB Electrical Characteristics in High-Layer Count Designs for High-Speed Data Center AI Systems

Copper thickness significantly influences board thickness and plays a crucial role in its design. While the thickness of copper in power/ground layers is generally fixed due to the requirements of power and current delivery requirements, this limitation does not apply to signal layers. In typical stack-up configurations, signal layers usually are about 1.2 mils in thickness, corresponding to one-ounce (oz) of copper. However, an alternative exists for signal layers: opting for half-ounce (0.5 Oz) copper, which is approximately 0.6 mils thickness. This choice can effectively reduce the overall board thickness by 0.6 mils for each signal layer, presenting a viable solution to manage and optimize board thickness constraints.