The Process And Advantages of Multilayer Circuit Boards with Different Numbers of Layers

Four-Layer Circuit Board (4-Layer)
1. Layer Structure
Typical stack-up:
Layer → Prepreg → GND Layer → Core → PWR Layer → Prepreg → Bottom Layer
(Top signal, ground, power, bottom signal)

. Core Advantages
Cost-effective: Compared to a double-sided board, adding a power/ground layer, the cost is only 50%~60% of six-layer board.

Signal integrity optimization: Dedicated power/ground planes reduce noise and support signal transmission from 100MHz to 1GHz.

at dissipation capability: Through large-area copper foil heat dissipation, suitable for medium-power devices.

3. Typical Applications
Consumer electronics: Smartphone mainboards,.

Industrial control: PLC modules, motor driver boards.

Automotive electronics: In-vehicle information and entertainment systems (IVI).

Second six-layer circuit board (6-Layer)
1. Layer Structure
Typical stack-up:
Top → Prepreg → GND → Core → Signal → Prepreg → Signal 2 → Core → PWR → Prepreg → Bottom
(Top signal, ground, inner signal 1/2, power, bottom)

2. Core Advantages
High-speed signal support: Isolate high-speed signals through shielding layers (ground layers), more precise impedance control, and 1~5GHz signals.

EMI suppression: Add a reference plane to reduce crosstalk and radiation.

Increased routing density: More signal layers complex circuits (such as BGA packaged chips).

3. Typical Applications
Communication equipment: 5G base station RF modules, switch motherboards.
Computer hardware: Server motherboards, graphics card PCBs.

Medical equipment: High-end monitors, image processing systems.

Third, eight-layer above circuit boards (8 Layer)
1. Layer Structure
Typical stack-up (for example, 8 layers):
Top → Prepreg → GND Core → Signal 1 → Prepreg → PWR → Core → Signal 2 → Prepreg → GND → Prepreg → Bottom
(Multiple layers of and power/ground are alternately arranged)

2. Core Advantages
Ultra-high density routing: Support 0.4mm pitch BGA, HDI buried hole design, and the component density is increased by 3~5 times.

Power integrity: Multi-power layer segmentation (such as 3.3V,5V, 12V), reduce voltage drop and noise.

High-frequency performance: Low dielectric loss material mixed pressing (such as FR-4 Rogers, support millimeter wave applications above 10GHz.

3. Typical Applications
Aerospace: Satellite communication module, flight control system.

High- computing: AI server motherboards, GPU accelerator cards.

Super high-frequency devices: Radar systems, millimeter wave antenna arrays.

Stackup selection guide
Four-layer board:

Application scenario: Limited budget, signal rate ≤ 1GHz, medium complexity design (such consumer electronics).

Avoid pitfalls: Avoid long-distance routing of high-frequency signals, and use a complete ground plane preferentially.

Sixlayer board:

Application scenario: High-speed digital circuits (DDR4/PCIe), radio frequency front-end modules (such as Wi-Fi ).

Optimization direction: Key signals are close to the ground plane, and power plane partitioning to reduce noise coupling.

Eight-layer board and above:
Application scenario: Ultra-high frequency communication (5G millimeter wave), multi-core processor systems (such as server CPU).

Design points: Optimize stack-up and impedance matching in combination with simulation tools (such as HFSS, SIwave).