FR402 is a high-performance, tetrafunctional epoxy-based laminate and prepreg system designed for advanced multilayer PCB applications. With its enhanced thermal stability, low dielectric loss, and high glass transition temperature (Tg), it is an excellent choice for high-reliability designs, including high-speed digital, RF/microwave circuits, and aerospace electronics.

Key Features

1. Material Composition

• Laminate: Made with a tetrafunctional epoxy resin system and reinforced with woven fiberglass for high mechanical and thermal stability.
• Prepreg: A resin-coated fiberglass material used for bonding in multilayer PCBs.

2. Thermal Properties

• Glass Transition Temperature (Tg): High Tg of 150°C–180°C, ensuring stability in high-temperature environments.
• Decomposition Temperature (Td): Typically around 330°C–350°C, suitable for lead-free soldering and thermal cycling.
• Low Coefficient of Thermal Expansion (CTE): Provides stability and reduces the risk of delamination, especially in the z-axis.

3. Electrical Properties

• Dielectric Constant (Dk): Stable Dk values, typically 3.7–3.9 at 1 GHz, for consistent electrical performance.
• Dissipation Factor (Df): Low Df, around 0.012–0.014, supports high-speed signal integrity and reduced signal loss.
• High Insulation Resistance: Excellent electrical isolation for reliable performance in multilayer designs.

4. Mechanical Properties

• Dimensional Stability: Excellent performance in multilayer PCB fabrication processes.
• Peel Strength: High copper adhesion strength ensures reliability under mechanical and thermal stress.

Applications

1. High-Speed Digital Circuits

• Optimized for networking equipment, telecommunication devices, and data servers requiring low signal loss and high reliability.

2. RF and Microwave Circuits

• Suitable for low-frequency RF circuits and antenna modules due to its stable dielectric properties.

3. Multilayer PCBs

• Ideal for high-layer-count PCBs with dense interconnects.

4. Aerospace and Defense Electronics

• Performs well under extreme environmental conditions, such as high thermal and mechanical stress.

5. Industrial and Automotive Electronics

• Used in control systems, motor drivers, and power electronics due to its thermal and mechanical durability.

Technical Specifications

Property	Typical Value
Glass Transition Temperature (Tg)	150°C–180°C
Decomposition Temperature (Td)	330°C–350°C
Dielectric Constant (Dk)	3.7–3.9 @ 1 GHz
Dissipation Factor (Df)	0.012–0.014 @ 1 GHz
Thermal Conductivity	~0.4 W/m·K
Coefficient of Thermal Expansion (CTE)	X/Y: ~13–16 ppm/°C, Z: < 60 ppm/°C
Peel Strength	> 8 lb/in
Flammability Rating	UL 94 V-0
Moisture Absorption	< 0.2%

Fabrication Guidelines

1. Storage and Handling

• Store prepregs in a cool, dry environment to prevent moisture absorption.
• Handle laminates with care to avoid contamination or surface damage.

2. Drilling and Hole Preparation

• Use sharp drill bits and optimized speeds to ensure clean hole walls.
• Perform desmear and plasma cleaning for enhanced hole-wall adhesion.

3. Lamination Process

• Use a recommended lamination cycle with controlled temperature ramp-up to ensure uniform bonding of layers.

4. Soldering and Assembly

• Compatible with lead-free soldering due to its high Tg and thermal stability.
• Use proper reflow profiles to prevent thermal stress during assembly.

Advantages

• Thermal Stability: High Tg and Td ensure excellent performance in thermal cycling and reflow processes.
• Electrical Performance: Low Df and stable Dk make it ideal for high-speed and high-frequency designs.
• Durability: Mechanically robust and resistant to delamination and moisture.
• Versatility: Suitable for a wide range of industries and applications.

The FR402 laminate and prepreg system offers a high-performance solution for demanding PCB designs, delivering thermal reliability, low signal loss, and mechanical strength. It is particularly suited for high-speed digital, RF, and aerospace applications, ensuring long-term reliability in challenging environments.

For detailed specifications and process recommendations, consult the manufacturer’s datasheet.