Multilayer Printed Circuit Boards (PCBs) or Multilayer Boards (MLBs) feature more than two copper layers, interconnected using copper-plated holes. These holes may include NC vias, laser microvias, through-holes, buried, or blind vias. The layers consist of copper foil, prepreg (PP), or adhesive materials and are pressed together under high temperature and pressure. This process removes air and cures the thermosetting adhesives, forming a cohesive multilayer PCB