# HDI Multilayer PCB Design & Manufacturer, Rapid Prototyping

_Published: 2025-09-19_

Table of Contents

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- What Is a HDI Multilayer PCB?
- 8 Layers HDI PCB Stackup
- What Are Applications of HDI Multilayer PCB?
- HDI Multilayer Circuit Board Technical Parameter
- How to Design a Multilayer HDI PCB?
- How Are Multilayer HDI PCBs Made?
- Why Choose EBest Circuit (Best Technology) as HDI Multilayer PCB Manufacturer?
- Our HDI PCB Capabilities
- How to Get a Quote for HDI Multilayer PCB Project?

What is a **[HDI multilayer PCB](https://www.bestpcbs.com/blog/2025/09/hdi-multilayer-pcb-design-manufacturer-rapid-prototyping/)**? Let’s discover its stackup, applications, technical parameter, design guide and manufacturing process through this blog.

**Are you troubled with these problems?**

- Struggling with sub-0.1mm microvia fabrication in traditional PCB processes?
- Facing high costs from signal loss in high-speed products?
- Delayed by slow 8+ layer HDI prototyping impacting launches?

**As a HDI multilayer PCB manufacturer, EBest Circuit (Best Technology) can provide you service and solutions:**

- Microvia Precision: 0.05mm laser-drilled vias with plasma treatment for compact designs.
- Signal Stability: End-to-end SI/PI support for 10Gbps+ stable transmission.
- Rapid Prototyping: 7-day standard lead time for 8-layer HDI, 5 days for urgent orders.

**Welcome to contact us if you have any request for [HDI multilayer PCB](https://www.bestpcbs.com/products/HDI-board.htm): sales@bestpcbs.com.**

## What Is a HDI Multilayer PCB?

**[HDI Multilayer PCB](https://www.bestpcbs.com/blog/2025/09/hdi-multilayer-pcb-design-manufacturer-rapid-prototyping/)** (High-Density Interconnect Multilayer Printed Circuit Board) is an advanced circuit board that employs precision microvias (aperture ≤0.15mm), blind/buried via technology, and ultra-fine lines (line width/spacing ≤3mil). Through laser drilling and layer-by-layer stacking processes, it achieves high-density routing across 8 or more layers within compact spaces. This design enhances signal transmission speed, reduces interference, and is specifically engineered for miniaturized, high-performance applications such as 5G devices and wearable electronics.

[https://www.bestpcbs.com/blog/wp-content/uploads/2025/09/main-23.jpg](https://www.bestpcbs.com/blog/wp-content/uploads/2025/09/main-23.jpg)

## 8 Layers HDI PCB Stackup

**Layer**
**Layer Type**
**Main Function**
**Connection Method**

L1
Signal Layer
High-frequency signal transmission / Critical component routing
Surface Blind Via (Connecting to L2)

L2
Power/Ground Plane
Power distribution / Ground network
Buried Via (Connecting to L3-L6), Blind Via (Connecting to L1/L3)

L3
Signal Layer
Inner-layer high-speed signal routing
Buried Via (Connecting to L2/L4)

L4
Signal Layer
Inner-layer control signal routing
Buried Via (Connecting to L3/L5)

L5
Signal Layer
Inner-layer low-speed signal routing
Buried Via (Connecting to L4/L6)

L6
Power/Ground Plane
Power distribution / Ground network
Buried Via (Connecting to L5/L7), Blind Via (Connecting to L7)

L7
Signal Layer
Inner-layer auxiliary signal routing
Blind Via (Connecting to L6/L8)

L8
Signal Layer
High-frequency signal transmission / Critical component routing
Surface Blind Via (Connecting to L7)

## What Are Applications of HDI Multilayer PCB?

Applications of **HDI multilayer PCB**:

- Smartphones & Mobile Devices: Mobile phone motherboard, Camera module, Sensor module, Antenna system, Automotive Electronics.
- Engine Control Unit (ECU): In-vehicle navigation system, Airbag control module, Advanced Driver Assistance System (ADAS), In-vehicle entertainment system.
- Medical Equipment: MRI imaging equipment, Cardiac pacemaker, Implantable medical devices, Precision diagnostic instruments, Communication Equipment.
- 5G base station: Router/switch, Fiber optic communication module, Satellite communication equipment.
- Industrial Control: Industrial robot control board, PLC control system, Automated sensor network.
- Servers & Data Centers: High-performance server motherboard, Cloud computing hardware, Data storage devices.

## HDI Multilayer Circuit Board Technical Parameter

**Parameters            **
**Specifications**

Layer Range
8-24 Layers

Minimum Line Width/Spacing
40/40μm

Laser Drill Hole Diameter
0.1mm

Mechanical Drill Hole Diameter
0.15mm

Blind/Buried Via Diameter
75-150μm

Aspect Ratio
<0.8:1

Blind Via Stack Spacing
≥0.3mm

Substrate Type
Rogers/Panasonic MEGTRON/FR-4

Surface Treatment     
ENIG/Immersive Silver/OSP

Tolerance Range
±7%

Pressing Method
Vacuum Lamination

Dielectric Thickness Uniformity
≤±10%

Plating Process – Copper Thickness Uniformity
≤±5μm

Thermal Resistance
-55°C to +125°C

Thermal Shock Test Cycles
≥1000 Cycles

Routing Density
>20 pads/cm²

Insulation Resistance
≥10MΩ

Reliability Testing                
≥500MΩ

## How to Design a Multilayer HDI PCB?

Below is [Multilayer HDI PCB design](https://www.bestpcbs.com/blog/2025/09/hdi-multilayer-pcb-design-manufacturer-rapid-prototyping/) guide:

**1. Modular Schematic Design with Precision**

- Divide schematics into functional modules (power, signal processing, interfaces) using hierarchical design.
- Annotate exact component parameters (e.g., 0.4mm pitch BGA CPU) and solder pad dimensions to ensure logical correctness and manufacturability.

**2. Advanced Stack-up Structure Planning**

- Implement “signal-power-ground” alternating stack-up (e.g., 3-layer signal/3-layer power/3-layer ground).
- Place high-speed signals on outer layers (trace width/space ≤4mil) with microvias (60-150μm laser-drilled) for layer-to-layer connections.
- Use buried vias for interlayer routing (e.g., 1-2 layer blind via + 3-4 layer buried via) and select materials like Rogers 5880 (Dk=2.2) for high-frequency scenarios or FR4-Tg180 for thermal stability.

**3. Intelligent Component Placement with Thermal Optimization**

- Center critical components (e.g., BGA-packaged CPU/FPGA) and position heat-generating devices near thermal via arrays.
- Use “escape routing” from BGA centers to minimize trace length. Implement grid-pattern thermal vias (≥150 vias/inch², 0.3mm diameter, 1.0mm spacing) and thermal interface materials (TIMs) with ≥5W/m·K conductivity for efficient heat dissipation.

**4. High-Speed Signal Routing with Strict Rules**

- Enforce differential pair length matching (≤2mil difference) using serpentine routing for via delay compensation (bend radius ≥3× trace width).
- Avoid crossing power splits to reduce crosstalk. Use stacked microvia structures (e.g., VIA1-2 + VIA2-3) for higher routing density and impedance continuity at connectors via “cross-connection + ground shield” (3× trace width spacing) with GND via pairs ≤3mm apart.

**5. Optimized Power/Ground Plane Design**

- Segment multi-layer planes with decoupling capacitor networks (0201 package 10nF+100nF parallel) to achieve PDN impedance ≤1Ω.
- Maintain continuous ground planes for low-impedance return paths (≤0.5mΩ) and use grid-pattern power planes to minimize eddy current losses.

**6. Detailed Impedance & Signal Integrity Control**

- Calculate trace width/spacing for target impedances (e.g., 6mil/7mil for 50Ω single-ended lines). At connector pads, implement “cross-connection + ground shield” with 3× trace width spacing.
- Add GND via pairs (≤3mm spacing) for transmission delay compensation and ensure via aspect ratios