One-Stop Multilayer PCB Manufacturing of 3 to 64 Layers

Structure and Core Material of Multilayer PCB

Multilayer PCBs are printed circuit boards with 3 or more copper layers. The lamination structure of a multilayer PCB is symmetrical, and the number of copper layers is even. Though 3-layer PCBs are rare, PCBONLINE can make a false 2-layer PCB with the middle layer without copper. We actually make multilayer PCBs from 4 to 64 layers.

4-layer, 6-layer, 8-layer, 12-layer, 16-layer, and 32-layer PCBs are commonly required by PCBONLINE's customers, the OEM terminal companies, and research institutes.

At PCBONLINE, the core materials of multilayer PCBs can be FR4, aluminum, copper, PI, PET, PTFE, or ceramic. They can be rigid, flexible, and rigid-flex. They can be high-density-interconnect (HDI), high-thermally conductive, high-voltage resistant, high-frequency, or transparent. Components can mount on one side or both sides.

For manufacturability and minimum warpage during PCB manufacturing, multilayer PCBs must have a symmetrical structure. However, it's possible to use different core materials for the same PCB, as long as the design is balanced and meets electromagnetic compatibility (EMC) requirements. We can do hybrid PCBs like FR4/copper, FR4/Rogers, FR4/PI, ceramic/copper, and FR4/PTFE/ceramic. Our professional engineers can help you improve your design if needed after our DFM checks.

At PCBONLINE, the wiring on multilayer PCBs is possible on up to 60 and 64 layers. Our multilayer PCB feature:

higher wiring densitysmaller product sizesmore circuit design flexibilityVia the ground and power layers, multilayer PCBs reduce electromagnetic interference(EMI)

Multilayer PCB Manufacturing

At PCBONLINE, the multilayer FR4 PCB manufacturing workflow is:

Cutting laminate > generating circuit in inner layers > lamination > drilling > copper plating > generating circuit in inner layers > automatic optical inspection (AOI) > solder mask and silkscreen > surface finish > profile > electrical test > final quality control > packaging.

In multilayer PCB fabrication, the lamination process must have no air trapped in the board, the resin in the prepreg melts and cures and the two adjacent conductive layers are bonded and insulated.

Before generating circuits in the outer layers, on the inner layers, there should be an oxidation layer, which roughens the copper surface to integrate with prepreg.

If the oxidation is Cu₂O, we call the multilayer PCB manufacturing method the "brown oxid" process; if the oxidation is CuO, we call the method the "black oxide" process.

For a multilayer PCB manufacturing process that requires HDI, the critical steps are microvia laser drilling, stacked/staggered via alignment, and sequential lamination. For multilayer PTFE/Rogers PCB manufacturing, the core steps are laminate sourcing & storage, impedance control, Plasma cleaning copper, and thermal shock testing. In a flexible multilayer PCB manufacturing process, the core steps are laser/mechanical drilling, adhesive and copper-thickness control, and surface finish. The other steps are similar to FR4 multilayer PCB manufacturing.

Copper Layer Quantity of Multilayer PCB

At the one-stop multilayer PCB manufacturer PCBONLINE, you can have any kind of multilayer PCB manufactured and assembled. The PCB layer quantity to fabricate is below:

FR4 multilayer PCB: 4-layer PCB, 6-layer PCB, 8-layer PCB, 10-layer PCB, 12-layer PCB, 14-layer PCB, 16-layer PCB... 60-layer PCB, and 64-layer PCBCeramic multilayer PCB: 4-layer PCBRigid-flex PCB: 3-layer PCB, 4-layer PCB, 6-layer PCB, 8-layer PCB, 10-layer PCB, 12-layer PCB... 24-layer PCBFlexible multilayer PCB: 4-layer PCB, 6-layer PCB, 8-layer PCBHigh-frequency PCB: 4-layer PCB, 6-layer PCB, 8-layer PCB, 10-layer PCB... 24-layer PCB

If you need multilayer PCB prototypes and bulk production, you can send your Gerber to info@pcbonline.com to get a quote or chat online with PCBONLINE.