Definition

Layer count is the total number of copper layers in a multilayer PCB. Boards range from single-sided (1 layer), double-sided (2 layers), to multilayer (4, 6, 8... up to 50+ layers). More layers provide more routing channels, dedicated ground/power planes, and support for fine-pitch BGAs, but increase cost and complexity. Layer count affects stackup design, drilling strategy, and manufacturing process selection. High-layer-count boards (>20 layers) require sequential lamination and careful registration.