HDI PCB Manufacturing
HDI PCB manufacturer with laser microvias from 0.075 mm, Anylayer construction, 0.35 mm BGA pitch and backdrill. High density interconnect fabrication for fine-pitch BGA, 01005 assembly and compact form factors — 4 to 24 layers.
When Standard Routing Is Not Enough
HDI PCB fabrication exists because modern chipsets — 0.35 mm pitch BGAs, 01005 passives, stacked-die packages — cannot escape a standard multilayer board. Mechanical through-holes are too large and consume routing channels on every layer. Laser microvias solve this by connecting only the layer pairs that need it.
As an HDI PCB manufacturer, we build boards from 4 to 24 layers with Anylayer sequential lamination, blind/buried vias, backdrill for high-speed stub removal, and controlled impedance to ±8%. Fabrication and assembly happen on the same campus, so HDI boards go straight to fine-pitch SMT placement and X-Ray inspection.
Why HDI Construction Matters
Three engineering reasons HDI is not just "more layers" — it is a fundamentally different routing approach.
Higher Density Per Layer
Laser-drilled microvias and fine-line routing let HDI boards fit more interconnects in less area than mechanically drilled boards — essential for 0.35 mm pitch BGA and 01005 component assemblies.
Better Signal Integrity
Shorter via paths and blind/buried via structures reduce stub length and parasitic capacitance, improving high-speed signal integrity for digital, RF and mmWave designs.
Anylayer Construction
Anylayer (sequential lamination) HDI allows microvias on every layer — not just outer layers — enabling the routing density that modern fine-pitch BGAs and chipsets require.
HDI Applications
Device categories where HDI is typically not optional.
Mobile & Consumer
Smartphones, tablets and wearables rely on HDI to fit dense interconnects into thin, compact form factors.
Medical Devices
Portable medical instruments and imaging modules use HDI for miniaturization with reliable signal paths.
RF & 5G
High-frequency modules and 5G antenna arrays benefit from short via paths and controlled impedance.
Automotive ADAS
Radar and camera modules for driver assistance use HDI to pack dense sensor interconnects into compact enclosures.
Wearables
Wearable health monitors combine rigid-flex HDI to fit sensors, radios and batteries in curved, compact housings.
High-Speed Digital
Server, networking and AI accelerator boards use HDI and backdrill for high-pin-count chipsets at controlled impedance.
HDI Fabrication Capabilities
The full technical envelope for HDI multilayer PCB — from laser microvia diameter to backdrill tolerance and impedance control.
- Laser microvias from 0.075 mm diameter
- Anylayer sequential lamination
- 0.35 mm BGA pitch with ENIG finish
- Backdrill ±3 mil for high-speed designs
| Parameter | Capability |
|---|---|
| Layer Count | 4 – 24 layers |
| Board Thickness | 0.27 – 3.4 mm |
| Min Laser Drill Diameter | ≥ 0.075 mm |
| Min Mechanical Drill | ≥ 0.15 mm |
| Microvia Aspect Ratio | 1:1 |
| Max PTH Aspect Ratio | 12:1 |
| Min Line/Space (Inner) | 0.05 / 0.05 mm |
| Min Line/Space (Outer) | 0.05 / 0.05 mm |
| Min BGA Pitch | 0.35 mm |
| Backdrill Tolerance | ± 3 mil |
| Layer Registration | 5 mil |
| Controlled Impedance | ± 8% (SET2DIL / Delta-L / VNA) |
| Line Width Tolerance | ±20% typical; ±10% advanced |
| Hole-wall Copper | 20 / 18 – 25 / 20 μm |
| Max Panel Size | 610 × 475 mm (24" × 18.7") |
HDI Structures We Build
Sequential lamination constructions for different density and signal requirements.
Through Hole (Standard)
Conventional plated through-holes with mechanical drilling. Used for lower-density HDI boards or as the base layer in sequential builds.
5+N+5 Symmetrical
Five microvia layers on each side of a central core (N). Common for high-pin-count BGA designs requiring dense routing on both outer regions.
Asymmetric HDI
Different microvia layer counts on each side — for designs where one side carries dense BGA routing while the other handles simpler power or signal layers.
Air-Gap Structure
Microvias with a gap in the dielectric between layers, reducing capacitive coupling for high-speed signal paths.
Anylayer (Sequential Lamination)
Microvias can appear on any layer, not just outer layers. Each layer pair is laminated and drilled sequentially — the highest density HDI construction.
Stacked & Staggered Vias
Microvias can be stacked (vertically aligned) or staggered (offset) to connect specific layer pairs as the routing requires.
Why Choose Our HDI Fabrication
Documented HDI Process
HDI fabrication follows documented sequential lamination procedures with controlled drill, desmear and plating parameters — the same standards whether you order 5 boards or 5,000.
HDI-Specific DFM Review
Engineers review microvia placement, pad-to-via relationships, aspect ratios and stack-up design before production, catching routing risks while they are still cheap to fix.
Signal Integrity Verification
Controlled impedance to ±8% with SET2DIL, Delta-L and VNA verification. Backdrill depth tolerance ±3 mil for high-speed stub removal.
Fab + Assembly Under One Roof
HDI boards can go directly to SMT assembly — including 0.35 mm pitch BGA with X-Ray inspection — without waiting for transit between suppliers.
Inspection & Verification
Automated optical inspection of outer-layer traces, pads and microvia registration on every panel.
X-Ray verification of microvia fill, layer alignment and buried via connections on assembled HDI boards.
SET2DIL, Delta-L and VNA-based impedance verification to ±8% for high-speed signal paths.
HDI PCB FAQ
Technical questions about microvias, Anylayer construction and BGA pitch.
A High Density Interconnect (HDI) PCB uses laser-drilled microvias (typically 0.075 mm or smaller), blind and buried vias, and finer trace/space geometry than standard mechanically drilled boards. HDI enables higher routing density per layer, which is required for high-pin-count fine-pitch BGA packages (down to 0.35 mm pitch), 01005 component assemblies, and compact form factors like mobile devices.
Standard multilayer PCBs use mechanically drilled through-holes (≥0.15 mm) that pass through all layers, consuming routing space on every layer. HDI uses laser-drilled microvias that connect only specific layer pairs, freeing routing channels on other layers. HDI also supports finer trace/space (down to 0.05 mm) and Anylayer construction where microvias can appear on any layer — not just outer layers.
Anylayer HDI is a sequential lamination construction where microvias can be placed on any layer pair, not just the outer layers. Each copper layer pair is laminated, laser-drilled and plated in sequence. This provides the highest routing density — essential for designs with multiple high-pin-count fine-pitch BGAs that cannot be routed with outer-layer-only microvias.
We support BGA pad pitches down to 0.35 mm on HDI boards. This requires laser microvias (≥0.075 mm), ENIG surface finish and HDI construction. For 1.0 mm pitch BGA, we can also apply backdrill with ±3 mil depth tolerance for high-speed signal integrity.
A microvia is a laser-drilled hole, typically 0.075–0.15 mm in diameter, that connects two adjacent copper layers. Unlike mechanical drills, laser drilling can produce holes smaller than 0.15 mm. Our minimum laser drill diameter is 0.075 mm, with a maximum microvia aspect ratio of 1:1 (depth-to-diameter).
Yes. Backdrill (controlled-depth drilling) removes the unused portion of a plated through-hole to eliminate signal stubs that degrade high-speed signal integrity. We offer backdrill with a depth tolerance of ±3 mil — suitable for high-speed digital designs where stub length matters.
Yes. Our SMT assembly lines handle 0.35 mm pitch BGA, QFN, LGA and 01005 components, with X-Ray inspection for hidden joints. Fabrication and assembly happen on the same campus, so HDI boards can go directly from lamination to SMT without inter-supplier transit.
Standard HDI uses high-Tg FR-4 laminates from qualified suppliers (Rogers, Panasonic, Nelco, TUC, Isola, ITEQ, SYTECH, Nanya and others). For high-speed designs, we offer mid-loss, low-loss, very-low-loss and ultra-low-loss materials. Halogen-free and high-Tg options are available for automotive and industrial applications.
Start Your HDI PCB Project
Send your stack-up, BGA pitch requirements and impedance targets — get an HDI-specific quote within 24 hours.