FR408 is a high-performance FR-4 epoxy laminate and prepreg system engineered to meet the demands of high-speed digital, RF/microwave, and advanced multilayer PCB applications. With its superior thermal reliability, low dielectric constant (Dk), and low dissipation factor (Df), FR408 is ideal for circuits requiring high signal integrity and thermal stability.

Key Features

1. Material Composition

• Laminate: Made with a modified FR-4 epoxy resin system and reinforced with high-quality woven fiberglass for mechanical and electrical stability.
• Prepreg: Resin-coated fiberglass for reliable interlayer bonding in multilayer PCBs.

2. Thermal Properties

• Glass Transition Temperature (Tg): High Tg of 180°C, providing stability during thermal cycling and lead-free soldering.
• Decomposition Temperature (Td): Typically around 340°C, ensuring performance under high thermal stress.
• Low Coefficient of Thermal Expansion (CTE): Excellent dimensional stability, particularly in the z-axis, reducing the risk of delamination and via failures.

3. Electrical Properties

• Dielectric Constant (Dk): Stable and low Dk, typically 3.6–3.8 @ 1 GHz, enabling high-speed signal propagation.
• Dissipation Factor (Df): Very low Df, around 0.009–0.011 @ 1 GHz, minimizing signal loss.
• High Volume Resistivity: Provides excellent electrical insulation for dense designs.

4. Mechanical Properties

• Dimensional Stability: Maintains accuracy and stability during fabrication and operation.
• Peel Strength: High copper adhesion strength ensures durability in multilayer stack-ups.

Applications

1. High-Speed Digital Circuits

• Perfect for networking equipment, data centers, and telecommunication devices demanding minimal signal loss and high reliability.

2. RF and Microwave Circuits

• Suitable for low-frequency RF applications, antennas, and microwave modules due to its stable dielectric properties.

3. Multilayer PCBs

• Designed for high-layer-count designs, including boards with dense interconnects.

4. Aerospace and Automotive Electronics

• Performs reliably under extreme thermal and mechanical stress.

5. Industrial Electronics

• Utilized in control systems, power distribution, and motor drivers.

Technical Specifications

Property	Typical Value
Glass Transition Temperature (Tg)	180°C
Decomposition Temperature (Td)	~340°C
Dielectric Constant (Dk)	3.6–3.8 @ 1 GHz
Dissipation Factor (Df)	0.009–0.011 @ 1 GHz
Coefficient of Thermal Expansion (CTE)	X/Y: ~14–16 ppm/°C, Z: < 60 ppm/°C
Thermal Conductivity	~0.4 W/m·K
Peel Strength	> 8 lb/in
Flammability Rating	UL 94 V-0
Moisture Absorption	< 0.2%

Fabrication Guidelines

1. Storage and Handling

• Store in a dry, controlled environment to prevent moisture absorption.
• Avoid contamination or physical damage to ensure optimal performance.

2. Drilling and Hole Preparation

• Use precision drilling with optimized feed and speed settings to produce clean holes.
• Employ desmear and plasma cleaning for enhanced hole-wall plating adhesion.

3. Lamination Process

• Follow the recommended press cycle, including controlled temperature and pressure, to ensure uniform layer bonding.

4. Soldering and Assembly

• Fully compatible with lead-free soldering profiles due to its high Tg.
• Use recommended reflow profiles to minimize thermal stress during assembly.

Advantages

• Thermal Stability: High Tg and Td ensure reliability in demanding environments.
• Electrical Performance: Low Dk and Df minimize signal loss and maintain signal integrity at high frequencies.
• Durability: Excellent mechanical and thermal reliability for long-lasting performance.
• Versatility: Applicable to a wide range of industries and high-performance applications.

The FR408 laminate and prepreg system offers a robust solution for advanced circuitry applications, balancing thermal reliability, signal integrity, and mechanical durability. Its superior properties make it an excellent choice for industries such as telecommunications, aerospace, automotive, and industrial electronics.

For detailed process parameters and additional support, refer to the manufacturer’s datasheet or consult technical experts.