185HR is a high-performance laminate and prepreg material designed for use in high-reliability printed circuit boards (PCBs). It offers a combination of high glass transition temperature (Tg), excellent thermal stability, and low electrical loss, making it ideal for advanced applications such as high-speed digital circuits, multilayer PCBs, and aerospace electronics.

Key Features

1. Material Composition

• Laminate: Made from advanced epoxy resin systems reinforced with woven fiberglass.
• Prepreg: A resin-coated fiberglass fabric used as the dielectric layer in multilayer PCB stackups.

2. Thermal Properties

• Glass Transition Temperature (Tg): 185°C, ensuring stability at elevated operating temperatures.
• Decomposition Temperature (Td): Typically around 350°C, offering excellent thermal durability.
• Low Coefficient of Thermal Expansion (CTE): Enhances reliability by minimizing expansion during thermal cycling.

3. Electrical Properties

• Dielectric Constant (Dk): Stable across a wide frequency range, typically 4.2 to 4.5 at 1 GHz.
• Dissipation Factor (Df): Low dissipation factor, typically 0.009–0.010, ensuring signal integrity in high-speed applications.
• High Insulation Resistance: Provides excellent electrical isolation.

4. Mechanical Properties

• Dimensional Stability: Maintains structural integrity during PCB fabrication processes, including drilling and etching.
• Flexural Strength: High mechanical strength ensures durability in multilayer stackups.

Applications

1. High-Speed Digital Circuits

• Suitable for networking, telecommunications, and server applications requiring high signal integrity.

2. Aerospace and Defense

• Used in avionics and military systems where thermal and mechanical reliability are critical.

3. Multilayer PCBs

• Ideal for stackups with dense interconnects and multiple signal layers.

4. Industrial Electronics

• Performs well in harsh environments, including industrial controls and high-power equipment.

Technical Specifications

Property	Typical Value
Glass Transition Temperature (Tg)	185°C
Decomposition Temperature (Td)	~350°C
Dielectric Constant (Dk)	4.2–4.5 @ 1 GHz
Dissipation Factor (Df)	0.009–0.010 @ 1 GHz
Thermal Conductivity	0.4 W/m·K
Coefficient of Thermal Expansion (CTE)	X/Y: ~12 ppm/°C, Z: < 60 ppm/°C
Peel Strength	> 8 lb/in
Flammability Rating	UL 94 V-0

Fabrication Guidelines

1. Storage and Handling

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

2. Drilling and Hole Preparation

• Use sharp, clean drill bits to minimize delamination.
• Perform desmear and hole-wall preparation processes for optimal plating adhesion.

3. Lamination Process

• Follow the recommended press cycle to ensure proper curing of prepregs and alignment of layers.

4. Soldering and Assembly

• Compatible with lead-free soldering processes due to its high Tg.

Advantages

• Thermal Stability: High Tg and Td ensure reliable performance in thermal cycling and reflow soldering processes.
• Electrical Performance: Low Df and stable Dk make it suitable for high-speed and high-frequency designs.
• Mechanical Strength: Withstands mechanical stress during fabrication and operation.
• Versatility: Suitable for both digital and RF/microwave applications.

The 185HR laminate and prepreg provide a robust solution for demanding PCB applications requiring thermal reliability, low signal loss, and mechanical durability. With its high Tg and excellent electrical properties, it is a preferred choice for multilayer PCB designs in telecommunications, aerospace, automotive, and industrial electronics.

For more detailed information, consult the manufacturer’s datasheet or application notes.