Skip to content
Home / PCB Fabrication / HDI PCB

High-density interconnect manufacturing

HDI PCB Manufacturing for Dense Interconnects

EBest PCBA reviews laser microvias, blind and buried connections, fine-line routing and via-in-pad features for compact PCB builds. Send your stack-up, via specifications and board files to confirm the fabrication structure and quotation scope.

We aim to provide an initial engineering response within 24 hours. Construction, pricing, test requirements and production lead time are confirmed from the design files.

HDI PCB construction PCB sample with dense routing and fine-pitch pad areas
PCB with dense routing and fine-pitch features.
HDI BUILD-UP1+N+1 / 2+N+2 / 3+N+3Build-up and via structure reviewed for your design.
ADVANCED INTERCONNECTSAny-Layer HDIConstruction and availability confirmed by project review.
LASER MICROVIAS0.10 mmVia size and dielectric depth reviewed together.
VIA-IN-PADVia-in-Pad PlatedFill, planarization and cap plating by review

Start with the design constraint

When Should You Choose HDI for Your PCB?

HDI affects the stack-up, drilling sequence, registration, copper balance, and cost, so it should be considered before the layout is finalized.

Controlled-impedance multilayer PCB for dense electronic routing
High-density routing must be reviewed together with the stack-up, impedance, copper and assembly profile.
01

Fine-Pitch BGA Escape

Use microvias and finer geometry when through-hole fan-out consumes routing channels or blocks power and ground access.

02

Smaller Product Envelope

Reduce board area while balancing layer count, dielectric thickness, routing density, and reliability.

03

Blind or Buried Interconnect

Move selected connections between layers while controlling drill depth, target land, plating and sequential lamination requirements.

04

Via-in-Pad Requirements

Review fill, planarization, cap plating, pad size, and assembly requirements before approving the VIPPO structure for fabrication.

Construction selection

HDI Build-Up Options

Each additional build-up cycle adds process time and tighter registration requirements. EBest PCBA confirms the required structure from the layer connectivity, via map, and approved stack-up.

Build-Up Structure

Required layer transitions determine the number of laser-drilling and lamination cycles. Cost and lead time depend on the final build-up structure.

Standard structures and items requiring additional review are identified before quotation.
01

1+N+1 HDI

One build-up layer on each side of the core structure, with the via map approved. N denotes the core-layer structure.

Stack-up review
02

2+N+2 HDI

Two build-up layers on each side where additional transitions are required, subject to stack-up and process review.

Engineering evaluation
03

Any-Layer HDI

Selected layer-to-layer structures subject to complete connectivity and process evaluation.

Engineering evaluation

HDI Capability Review From Your Production Files

HDI PCB Manufacturing Capabilities

The stack-up, via map and copper define the approved HDI construction. The references below are evaluated as a complete build.

CapabilityProduction ReferenceConditions / Special Review
Laser microvia0.10 mm referenceHole-size definition, dielectric depth, aspect ratio, capture pad and plating or fill confirmed.
Finished mechanical hole0.20 mm minimum reference0.15 mm by review; board thickness, plating and tolerance confirmed.
Inner line width / spacing4 / 4 mil at 0.5–1 oz copper reference3 / 3 mil by review; base and finished copper, etching and layer-specific geometry confirmed. Outer layers assessed separately.
Through-hole aspect ratioUp to 8:1 referenceUp to 10:1 by review; hole size, thickness and plating must form an approved combination.
HDI build-up1+N+1 after stack-up review2+N+2, stacked or staggered microvias and Any-Layer by project evaluation.
Total layer countDefined by the approved HDI stackBuild-up layers, core structure, registration and lamination sequence determine the construction.
Via-in-pad / VIPPOSelected filled, planarized and capped structuresVia type, copper or specified fill material, cap plating, pad flatness and assembly requirements confirmed.
Surface finishSelected for the approved assembly interfaceOSP, ENIG, silver or tin; HASL where pad flatness permits; ENEPIG or hard gold by review.
Controlled impedanceTarget and tolerance agreed from the stack-upMaterial data, dielectric thickness, finished copper, reference planes, coupons and testing confirmed.

Line width and spacing are separate dimensions. A 0.10 mm microvia reference does not determine allowable depth or stacked-via qualification. The quotation confirms the complete construction and inspection or reliability scope. For conventional layer options, see FR4 and multilayer PCB capabilities.

Not sure whether your stack-up needs HDI? Send Gerber or ODB++ files, the via map, and BGA pitch. EBest PCBA will confirm which features are within standard capability and which require additional review before quotation. Check My HDI Stack-Up

HDI Manufacturing Process

HDI Manufacturing and Inspection

The exact process depends on the approved build-up, materials, and inspection plan. Each lamination and drilling cycle is checked against the approved stack-up and via structure.

01 / FILE REVIEW

Stack-Up and Via Map

Check layer connectivity, microvia depth, target lands, copper and impedance requirements.

02 / BUILD-UP

Lamination and Laser Via

Control dielectric, laser depth, target lands and registration for each build-up cycle.

03 / COPPER

Metallization and Fill

Metallize and plate the approved interconnections. Apply specified microvia copper fill or selected mechanical-via resin fill according to via type, with planarization and cap plating where required.

04 / FINE LINE

Imaging and Etching

Protect fine geometry, copper balance and impedance-critical routing through production.

05 / FINISH

Surface and Assembly Interface

Confirm ENIG, OSP or project-specific finish against BGA, via-in-pad and soldering needs.

06 / FINAL QC

Inspection and Test

Complete electrical testing and agreed dimensional, microsection and final inspection. Qualification tests follow a separately agreed plan.

Engineering and inspection evidence

Microvia and Via-in-Pad Verification

Confirm target-land interfaces, specified copper fill, registration and cap-plated pad requirements. Mechanical-via resin fill and cap plating are defined separately from microvia copper fill.

DFM and Stack-Up Check

Review missing inputs, drill definitions, via-to-pad geometry, copper weight and the build sequence before quotation.

Registration Control

Confirm target-land access, annular relationships and layer alignment through the sequential build-up.

Microsection Evidence

Microsections assess specified plating, fill and interfaces. Reflow, thermal-stress and other reliability qualification require agreed coupons, methods and acceptance criteria.

Electrical and Impedance Test

Perform electrical testing and impedance verification against the approved data and coupon plan.

PCB sample during soldering and inspection
PCB sample during assembly review.

Supported HDI constructions

HDI Builds We Support

Match your BGA escape, signal-integrity and assembly requirements to the construction profiles below. Each build follows an approved stack-up and via map.

Physical HDI PCB with fine-pitch component and BGA pad areas
FINE-PITCH ROUTING

Fine-Pitch Processor Boards

Microvia fan-out assessed with BGA pitch, capture pads and routing channels.

Typical application: compact processing modules, embedded controllers and dense computing interfaces.
Build-up
1+N+1 reference; final layer transitions follow the approved via map.
Microvia
0.10 mm general reference; dielectric depth and capture-pad geometry remain file-specific.
Key review
BGA escape, stack-up, finished copper, impedance notes and assembly interface.
Production basis
Approved stack-up, drill data, review items, and inspection plan.
Discuss This HDI Build
Physical HDI PCB production panel with repeated dense circuit modules
SIGNAL INTEGRITY

Controlled-Impedance Communication Boards

Reference planes, dielectric data and layer transitions aligned with the impedance plan.

Typical application: network processors, communication modules and high-speed control equipment.
Build-up
Compare 1+N+1 and 2+N+2 based on required layer transitions and routing density.
Impedance
Trace geometry, dielectric values, copper and reference planes reviewed together.
Verification
Coupon, electrical test and microsection evidence when required by the approved construction.
Production basis
Approved impedance table, stack-up, via structure, and production test plan.
Discuss This HDI Build
Physical compact high-density control PCB panel with fine component features
COMPACT CONTROL

Compact Control Boards

Material, power routing and fine geometry selected for the assembly and service requirements.

Typical application: industrial controllers, compact instrumentation and high-temperature electronics.
Material
High-Tg FR-4 grade selected against assembly profile and operating conditions.
Geometry
Layer-specific copper and line/space limits checked before stack-up commitment.
Evidence
Registration, dimensional, and electrical records, plus any required inspection records.
Production basis
Approved fabrication data, material selection, and inspection plan.
Discuss This HDI Build

Industry applications

Applications for Dense Interconnects

Telecommunications network equipment

Telecommunications

Compact processors and communication interfaces with signal-integrity requirements.

Medical electronic diagnostic equipment

Medical Electronics

Compact sensing or monitoring modules with defined documentation needs.

Automotive electronic systems

Automotive Electronics

Selected sensing and control boards with defined thermal and mechanical requirements.

Industrial automation and control equipment

Industrial Control

Dense embedded controllers and communication assemblies.

Prepare a quote-ready review

What to Send for an HDI PCB Quote

Send your available design data, stack-up and via map. We will identify missing information, review the required build structure and confirm the quotation scope.

Gerber or ODB++ dataNC drill and laser-via filesProposed stack-upImpedance requirementsVia type and fill notesFinished copper requirementsSurface finish and assembly notesQuantity and delivery target

Request Your HDI PCB Quote

Share the files you have. Our team will review the stack-up, microvias, copper and assembly requirements, then confirm the next steps for pricing and production.

FAQ

HDI PCB Manufacturing Questions

How do blind vias, buried vias and microvias differ?
Blind vias connect an outer layer to internal layers. Buried vias connect internal layers without reaching either surface. Microvias are small-depth interconnects commonly formed by laser. Geometry and layer transitions are defined in the approved stack-up.
How do I choose an HDI build-up?
The via map, BGA escape, layer transitions and reliability requirements determine the construction. Additional build-up layers affect processing, registration, cost and qualification needs.
Can you review via-in-pad and VIPPO?
Yes, subject to file review. Send the via type, pad size, hole definition, fill, cap plating, surface finish and assembly requirements. Via-in-pad placement alone does not mean the via is filled and plated over.
What line width and spacing can be reviewed?
For 0.5–1 oz inner copper, 4/4 mil is the reference and 3/3 mil requires review. Outer-layer and different-copper geometry must be confirmed separately.
What files are needed for an HDI quote?
Send circuit data, drill and laser-via definitions, stack-up, via map, copper, impedance, finish, dimensions, quantity and any assembly or inspection requirements. Partial information can start a review.
How are stacked and staggered microvias evaluated?
The review covers dielectric depth, target pads, copper fill, interfaces, registration and build sequence. Qualification requirements are agreed for the actual structure rather than assumed from a generic via dimension.
Can HDI fabrication be combined with turnkey PCBA?
Yes, subject to project scope. Send the BOM, placement data and test requirements so via-in-pad, finish, assembly and testing can be coordinated.