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HDI & Advanced Interconnect Specialist

Blind & Buried Via PCB

Precision laser-drilled microvias with multi-step lamination technology. Enable higher density interconnects for your most demanding HDI designs — from smartphones to aerospace systems.

0.1mm
Min Microvia Diameter
20+
Lamination Cycles
3+N
HDI Build-up Stages
99.5%
Via Reliability Rate
Technology Overview

What Are Blind & Buried Vias?

Essential interconnect technologies for high-density interconnect (HDI) PCBs that maximize routing density while minimizing board size.

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Blind Vias

Vias that connect an outer layer to one or more inner layers without passing through the entire board. Laser-drilled for precision, they free up routing space on inner layers that would otherwise be blocked by through-hole vias.

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Buried Vias

Vias that connect inner layers only, completely invisible from the board surface. They eliminate via stubs, improve signal integrity, and allow more components and traces on outer layers.

Microvias

Laser-drilled vias with diameters typically ≤0.15mm. Used in sequential lamination HDI builds (1+N+1, 2+N+2, 3+N+3 patterns) for ultra-high-density designs like smartphones and wearables.

Technical Specifications

Blind & Buried Via Capabilities

Our advanced HDI manufacturing line delivers precision microvias with industry-leading reliability.

Via Diameter

0.1mm
Min laser-drilled microvia

Aspect Ratio

1:1
Via depth to diameter ratio

Pad Diameter

0.25mm
Min capture pad size

HDI Stack-up

3+N+3
Max build-up stages

Layer Count

4–32L
Supported layer range

Lamination

20+
Sequential lamination cycles

Via Fill

100%
Copper / epoxy resin fill

Registration

±0.05mm
Layer-to-layer alignment
Our Advantages

Why Choose Topfast for HDI Vias

Dedicated HDI production line with state-of-the-art laser drilling and plating systems.

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UV & CO₂ Laser Drilling

Dual-laser system for precise microvia formation. CO₂ laser for larger vias and UV laser for ultra-fine microvias down to 0.1mm diameter with clean, taper-free walls.

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Advanced Copper Fill

Proprietary copper plating process for reliable 100% via fill. Eliminates voids and air traps, ensuring excellent thermal and electrical conductivity through each via.

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Precise Registration

Optical alignment systems with ±0.05mm accuracy across multiple lamination cycles. X-ray inspection verifies inner-layer alignment for every HDI panel.

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Reliability Testing

100% cross-section analysis on first articles. Thermal cycling, pull test, and shear test on filled vias to guarantee long-term reliability under demanding conditions.

Quick Turn HDI

Prototype HDI boards with blind/buried vias in as fast as 5 working days. Full DRC/DFM review included to optimize your design before fabrication.

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Design Support

Free HDI stack-up consultation and via structure optimization. Our engineers help you balance cost, density, and manufacturability for your specific application.

HDI Manufacturing Process

Sequential Lamination Flow

1

Core Laminate

Inner core layers are fabricated with buried vias, copper plating, and etching. AOI inspection ensures trace quality.

2

Laser Drill

UV/CO₂ laser drilling creates blind microvias in prepreg and copper foil with positional accuracy to ±0.025mm.

3

Plate & Fill

Electroless copper deposition followed by electroplating. Copper or epoxy resin fill eliminates voids in vias.

4

Test & Ship

100% E-test, AOI, X-ray inspection, and cross-section verification. IPC-A-600 Class 2/3 acceptance.

Applications

Where Blind & Buried Vias Shine

HDI technology with blind and buried vias enables the miniaturization and performance demands of today's most advanced electronics.

📱Smartphones & Tablets
Wearables & IoT Devices
💻Laptops & Ultrabooks
🛩️Aerospace & Defense
🏥Medical Implantables
🚗ADAS & Automotive ECU
📡5G RF Modules
🎮High-End GPUs & AI Accelerators

Need Blind & Buried Via PCB?

Upload your HDI design files — our engineers will review your stack-up and via structure for free, with a detailed quote within 24 hours.

Get Your HDI Quote →