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.
