Multilayer PCB manufacturer · Fabrication
Multilayer PCB Manufacturer: 4 to 30 Layer Boards
Controlled-impedance stack-ups, balanced copper and verified layer registration, from a 4-layer IoT board to a 30-layer server design. Every stack-up is reviewed in writing before fabrication.
- Layer count
- 4–30
- Min. line / space
- 50 µm
- Impedance tolerance
- ±8%
- Max. copper weight
- 10 oz
What is a multilayer PCB
More layers, cleaner signals, smaller boards.
A multilayer PCB has three or more copper layers, typically 4 to 30, bonded with prepreg and core dielectrics under heat and pressure and connected by plated vias. Dedicated ground and power planes provide controlled impedance, lower EMI and the routing density needed for processors, FPGAs and high-speed interfaces.
Each added layer pair gives more routing channels and better reference planes. It also adds material, lamination, drilling and imaging cost. The goal of multilayer PCB design is the smallest layer count that still meets the routing, impedance and power-delivery requirements.
As a multilayer PCB manufacturer, AstroPCB checks that a stack-up is balanced, buildable and able to hit its impedance targets with real material thicknesses before production. You get the review in writing with your quote.
- Dedicated ground and power planes for signal and power integrity
- Controlled impedance for USB, PCIe, DDR, Ethernet and SerDes
- Blind, buried and microvia options when through-holes run out of space
Cross-section of a multilayer board with plated through-hole.
Why AstroPCB
Why choose AstroPCB as your multilayer PCB manufacturer.
A multilayer PCB manufacturer proves itself in the stack-up review, not on the price list. We confirm layer order, dielectric thickness, copper balance and impedance against real material constructions before multilayer PCB fabrication begins.
- 4 to 30 layers on FR-4, high-Tg, Isola 370HR, Megtron and hybrid stack-ups
- X-ray registration and TDR impedance checks on controlled builds
- Engineering since 2008: 1,000+ engineers and 30+ partner factories in Shenzhen, Xi’an, Chengdu and Hangzhou
- Written DFM review on every order, prototype or production, before fabrication starts
- 99.6% on-time delivery across the partner factory network
- From 1 piece to volume with the same stack-up and process controls
- IPC Class 2 by default, Class 3 on request, with inspection records and batch traceability
- Fabrication plus assembly: component sourcing, SMT and tracked worldwide shipping
Multilayer PCB capabilities
Multilayer PCB fabrication capabilities.
These are planning limits, not defaults. Most multilayer designs build with better yield and lower cost well inside them.
| Parameter | AstroPCB capability |
|---|---|
| Layer count | 4 to 30 layers; higher layer counts reviewed per design |
| Copper weight | 0.5 oz to 10 oz (heavy copper on suitable FR-4 constructions) |
| Min. line / space | 50 / 50 µm |
| Min. mechanical drill | 0.10 mm |
| Via types | Through, blind, buried and laser microvias; epoxy-filled and capped vias |
| Layer-to-layer registration | ±3 mil (75 µm) standard; ±2 mil (50 µm) for HDI |
| Controlled impedance | ±8% with confirmed stack-up and TDR coupon verification |
| Materials | Standard and high-Tg FR-4, Isola 370HR, Megtron 6/7, Rogers hybrid stack-ups |
| Surface finishes | HASL, lead-free HASL, ENIG, ENEPIG, immersion silver, immersion tin, OSP, hard gold |
| Acceptance standard | IPC-6012 Class 2 by default, Class 3 on request |
| Order quantity | From 1 prototype to volume production |
Layer count options
From 4-layer to high layer count PCBs.
Mainstream multilayer
IoT, industrial control, power and mixed-signal boards. Four layers adds solid ground and power planes; six and eight layers add controlled-impedance routing layers.
Complex digital
FPGA, SoC and embedded compute boards with large BGAs, DDR memory and multiple high-speed interfaces. Often combined with blind/buried vias or HDI.
High layer count PCB
AI servers, switches, backplanes and ATE boards, built on low-loss materials with tight thickness, registration and impedance control.
Typical stack-ups
Common multilayer stack-up starting points.
| Layers | Typical layer order | Notes |
|---|---|---|
| 4 | SIG / GND / PWR / SIG | Lowest-cost multilayer with solid reference planes |
| 6 | SIG / GND / SIG / PWR / GND / SIG | Inner stripline layers for controlled impedance |
| 8 | SIG / GND / SIG / PWR / GND / SIG / GND / SIG | Every signal layer next to a reference plane |
| 10+ | Alternating signal and plane pairs, symmetric about the core | Required for DDR, PCIe and multi-rail power delivery |
- Keep the stack-up symmetric about the center to prevent bow and twist during lamination and reflow.
- Balance copper on paired layers. A heavily filled layer opposite a sparse one creates warp stress.
- Place every high-speed layer next to a solid reference plane and avoid routing across plane splits.
- Specify impedance by layer and reference and let us adjust dielectric thickness to real material constructions.
- Use the minimum layer count that routes. Sometimes HDI or a slightly larger outline saves a layer pair.
Try the stackup calculator and impedance calculator.
Example 8-layer controlled-impedance stack-up.
Multilayer materials
Laminates by performance requirement.
FR-4 and high-Tg FR-4
The default for most multilayer boards. High-Tg grades add thermal margin for lead-free assembly and higher layer counts.
FR-4 material guideIsola 370HR
A high-reliability, high-Tg FR-4 class laminate widely used for thick, high-layer-count boards.
Isola 370HRMegtron 6 / 7 & hybrid builds
Low-loss laminates for high-speed digital, plus hybrid stack-ups that put Rogers on RF layers and FR-4 elsewhere to control cost.
Megtron materialsHow multilayer PCBs are made
Multilayer PCB fabrication process, step by step.
Multilayer PCB fabrication follows the same core sequence at 4 layers or 40. What changes is the number of lamination, drilling and plating cycles.
- Engineering & CAM: DFM review, stack-up confirmation and panelization.
- Inner-layer imaging and etching, followed by AOI of every inner layer.
- Oxide treatment and lay-up of cores, prepreg and copper foil.
- Lamination under heat and pressure, with X-ray registration targeting.
- Drilling (mechanical and laser) and copper plating of holes.
- Outer-layer imaging, etching and plating.
- Solder mask, legend and surface finish.
- Electrical test, impedance test and final inspection before packing.
Blind and buried vias or HDI build-ups repeat the lamination, drilling and plating steps for each sequential stage. See blind & buried vias.
Quality & verification
How every multilayer board is verified.
- Written DFM review of stack-up, impedance and copper balance
- AOI on every inner and outer layer
- X-ray registration checks after lamination
- TDR impedance testing on controlled-impedance coupons
- 100% electrical test (flying probe or fixture)
- Microsection analysis of plating thickness and hole quality
- IPC-6012 Class 2 or 3 acceptance, with inspection records on request
Multilayer PCB cost
What drives multilayer PCB cost.
- Layer count: each layer pair adds core, prepreg, imaging and inspection
- Lamination cycles for blind/buried vias or HDI
- Material: standard FR-4 vs high-Tg vs low-loss
- Copper weight and plating requirements
- Fine features: line/space and drill sizes near the limit
- Board size, panel utilization and quantity
- Impedance control, surface finish and IPC class
- Lead time: see quick turn PCB options
Upload your design for an exact price. Our engineers will flag any change, such as layer count, material or via type, that lowers cost without affecting performance.
Request a multilayer quote
What to include in your multilayer RFQ.
- Gerber, ODB++ or IPC-2581 data plus fabrication drawing
- Layer count, finished thickness and preferred layer order
- Copper weight per layer
- Impedance table with layers and reference planes
- Drill table: through, blind, buried and filled vias
- Material preference and allowed substitutes
- Surface finish, IPC class and test requirements
- Quantities and target delivery date
FAQ
Multilayer PCB questions, answered.
What is a multilayer PCB?
A multilayer PCB has three or more copper layers, typically 4 to 30, laminated together with dielectric material and connected by plated vias. It allows dense routing plus dedicated ground and power planes.
How many layers can AstroPCB manufacture?
AstroPCB manufactures multilayer PCBs from 4 to 30 layers. Higher layer counts for servers, networking and backplanes are reviewed per design.
How do I choose the number of layers?
Start from the number of signal layers needed to route your densest area, such as the BGA fan-out. Add the ground and power planes those layers need for impedance and power delivery, then keep the stack-up symmetric. Four layers is the minimum for solid planes; six to eight layers is typical once controlled impedance is needed.
What material is used for multilayer PCBs?
Most multilayer boards use FR-4 or high-Tg FR-4. High-speed designs use low-loss materials such as Megtron 6/7, and RF designs often use hybrid stack-ups that combine Rogers and FR-4.
What is your layer-to-layer registration tolerance?
Standard registration is ±3 mil (75 µm). HDI designs with microvias are held to ±2 mil (50 µm).
Can you control impedance on multilayer boards?
Yes. Controlled impedance is available to ±8% with a confirmed stack-up and TDR coupon testing. Send the target impedance per layer and its reference planes.
What is the lead time for multilayer PCBs?
Lead time depends on layer count, material and via structure, and is confirmed with your quote. Quick-turn fabrication is available for eligible orders; see quick turn PCB.
Do you build multilayer prototypes in small quantities?
Yes. You can order from a single prototype board and scale to production with the same stack-up and process controls. See PCB prototype.
Ready when your files are
Send your multilayer stack-up for an engineering-reviewed quote.
Upload Gerber, ODB++ or IPC-2581 data. Every quote includes a written engineering DFM review, typically within one business day.