Laminated unit for printed circuit board and printed circuit board

A printed circuit board comprising a plurality of laminated units stacked in a thickness direction, wherein each of the plurality of laminated units comprises:

• a plurality of metal layers and a plurality of dielectric layers alternately stacked in the thickness direction,
• wherein the plurality of metal layers comprise a signal transmission layer and a pair of reference layers disposed on two sides of the signal transmission layer;
• at least one of two dielectric layers adjacent to the signal transmission layer comprises a resin isolation layer;
• and
• dielectric layers on sides of the pair of reference layers opposite to the signal transmission layer comprise a reinforcing layer, and the reinforcing layer comprises a substrate and a resin material arranged around the substrate,
• wherein one of the two dielectric layers adjacent to the signal transmission layer comprises the resin isolation layer, and the other dielectric layer comprises the reinforcing layer.