Multilayer PCB

A multilayer printed circuit board (PCB) is an electronic interconnect structure composed of three or more conductive copper layers separated by insulating dielectric substrates (typically FR-4 epoxy glass), which are bonded together under heat and pressure using prepreg materials. These boards feature plated through-holes (vias) that electrically connect different layers, enabling complex circuit routing in a compact form factor. Multilayer PCBs provide enhanced functionality, reduced electromagnetic interference, and improved signal integrity compared to single or double-sided boards, making them essential for modern high-density electronic devices.

Multilayer PCBs function by providing electrical pathways between electronic components through patterned copper traces on multiple internal layers. Signals travel through conductive traces on different layers, with vias (plated holes) creating vertical connections between layers. The insulating dielectric materials prevent short circuits between adjacent conductive layers while providing mechanical support. This layered structure allows for complex circuit designs with crossovers, ground planes, and power planes that minimize noise and improve performance in high-frequency applications.