A multilayer printed circuit board has three or more copper layers. The layers are joined together to form one board. Plated through holes and vias make electrical connections between the layers.
A multilayer PCB can be rigid, flexible, or rigid-flex. A rigid-flex PCB combines rigid and flexible sections in one board. The flexible sections can bend or fold. They also connect the rigid sections.
Rigid-flex technology can replace separate PCBs, wires, cables, and connectors. This can reduce the number of parts, save space, and make assembly easier. It can also improve connection reliability and create a cleaner, more compact electronic assembly.