Multilayer PCB is a circuit board that has more than two layers.
Unlike a Double-Sided PCB which only has two conductive layers of material, all multilayer PCBs must have at least three layers of conductive material which are buried in the center of the material.Alternating layers of prepeg and core materials are laminated together under high temperature and pressure to produce Multilayer PCBs. This process ensures that air isn’t trapped between layers, conductors are completely encapsulated by resin, and the adhesive that holds the layers together are properly melted and cured. The range of material combinations is extensive from basic epoxy glass to exotic ceramic or Teflon materials.