Multilayer PCB consist of 3 or more circuit layers bonded together by a thickness of insulating material called prepreg and core. Multilayer printed circuit boards are most complicated than others, and are generally considered to be the most sophisticated PCB product due to their construction methods and design complexities.

These are a few of the applications using multilayer printed circuit boards:

General specification for Multi-layer printed circuit board

1, 4-38 layers
2, Board finished thickness: 0.3mm-7.0mm
3, Material: FR-4, CEM-1, CEM-3, High TG, FR4 halogen Free, Rogers, Telfon.
4, Max. Finished board size: 23*25(580*900mm)
5, Min. Drilled hole size: 6mil(0.15mm)
6, Min. Line width: 3mil(0.075mm), Min. Line spacing: 3mil(0.075mm)
7, Surface finish/treatment: HASL/HASL lead free, Chemical tin, ENIG,Immersion Silver, OSP, etc.
8, Copper thickness: 0.5-20 oz
9, Solder mask color: Green/yellow/black/white/red/blue
10, Copper thickness in hole: >25.0 um(>1mil)

1. 4 layers Semi hole multilayer printed circuit board

4Lsemi hole multilayer pcb
Technical description,
Material: FR-4 Tg150 Halogen free
Board thickness: 0.8mm
Surface finished: Immersion gold
Copper thickness: 1 Oz for all layers
Solder mask: TaiYo blue
Min through hole: 0.2mm
Consumer Electronics

2. 6 Layers multi-layer PCB

6L multilayer printed circuit board
Technical description,
Material: FR-4 Tg170
Board thickness: 1.58mm
Surface finished: Immersion gold
Copper thickness: 1 Oz for all layers
Min.line width/space: 5mil
Min through hole: 0.2mm
Medical

3. 10 layers Multilayer printed wiring board

10L multilayer printed wiring board
Technical description,
Material: FR-4 Tg170
Board thickness: 1.6mm
Surface finished: Immersion gold+Controlled Impedance
Copper thickness: H Oz for all layers
Min.line width/space: 3.5mil
Min through hole: 0.2mm
Communications

4. 10 layers multilayer pcb

10L multilayer pcb
Technical description,
Material: FR-4 Tg170
Board thickness: 1.6mm
Surface finished: Immersion gold+Controlled Impedance
Copper thickness: 1 Oz for all layers
Min.line width/space: 4mil
Min through hole: 0.15mm
Military

5. 18 layers multilayer board

18L multilayer board
Technical description,
Material: FR-4 Tg180
Board thickness: 2.2mm
Surface finished: Immersion gold+Controlled Impedance
Copper thickness: 1 Oz for all layers
Min.line width/space: 4mil
Min through hole: 0.25mm
Medical