RT-duroid® laminates are high-performance PTFE-based composite materials manufactured by Rogers Corporation. These laminates are primarily used in RF, microwave, and high-frequency applications due to their exceptional dielectric properties, thermal stability, and chemical resistance.

1. Composition of RT-duroid Composites

1. Base Material:
   • Polytetrafluoroethylene (PTFE): Provides a low-loss, stable dielectric medium with excellent high-frequency performance.
2. Reinforcements:
   • Glass Microfibers: Enhance mechanical stability and reduce dimensional changes.
   • Ceramic Fillers (in some variants): Improve thermal conductivity and reduce dielectric constant variation.
3. Copper Cladding:
   • Available in different thicknesses and types (e.g., rolled or electrodeposited copper) to meet specific circuit requirements.

2. Key Properties of PTFE-Based RT-duroid Laminates

Property	Performance
Dielectric Constant (ϵr\epsilon_rϵr​)	Low and stable (e.g., 2.20 for RT-duroid 5880).
Loss Tangent (tan⁡δ\tan \deltatanδ)	Very low (e.g., 0.0009 for RT-duroid 5880 at 10 GHz).
Thermal Stability	Wide operating range (-200°C to +200°C).
Moisture Absorption	Minimal (< 0.02%), ensuring consistent electrical performance.
Thermal Conductivity	Moderate (~0.2 W/m·K), suitable for RF applications.
Chemical Resistance	High resistance to solvents, acids, and bases.

3. Advantages of RT-duroid PTFE-Based Composites

1. Low Dielectric Loss:
   • Ideal for high-frequency and broadband applications with minimal signal attenuation.
2. Dimensional Stability:
   • Glass or ceramic reinforcements provide excellent stability during fabrication and use.
3. Wide Frequency Compatibility:
   • Effective across a broad frequency spectrum, from MHz to millimeter-wave applications.
4. Low Moisture Absorption:
   • Ensures reliable performance in humid or challenging environmental conditions.
5. Ease of Fabrication:
   • Compatible with standard PCB processing techniques, with proper handling.

4. Applications of RT-duroid Composites

1. Aerospace and Defense:
   • Radar systems, satellite communication modules, and avionics.
2. Telecommunications:
   • High-frequency antennas, microwave filters, and power dividers.
3. Automotive:
   • Advanced driver-assistance systems (ADAS) and radar applications.
4. Medical Devices:
   • High-frequency imaging systems and diagnostic tools.
5. Space Exploration:
   • Low outgassing properties make RT-duroid laminates suitable for vacuum and space environments.

5. Types of PTFE-Based RT-duroid Laminates

Grade	Dielectric Constant (ϵr\epsilon_rϵr​)	Key Features
RT-duroid 5870	2.33 ± 0.02	Low dielectric constant, glass reinforced.
RT-duroid 5880	2.20 ± 0.02	Ultra-low loss, glass reinforced.
RT-duroid 6000 Series	Varies (ceramic-filled)	Higher thermal conductivity, mechanical robustness.

6. Fabrication Guidelines

1. Drilling:
   • Use sharp carbide or diamond-coated tools to avoid fraying the PTFE matrix.
2. Etching:
   • PTFE’s inert surface requires special preparation (e.g., sodium etching) for metallization.
3. Lamination:
   • Follow controlled pressure and temperature cycles to avoid warping or delamination.
4. Thermal Expansion Management:
   • Use compatible materials to prevent stress during thermal cycling.

7. Comparison with Standard Materials (e.g., FR-4)

Property	RT-duroid	FR-4
Dielectric Constant	Low (e.g., 2.2 – 2.33)	Higher (e.g., 4.2 – 4.7)
Loss Tangent	Very low (e.g., 0.0009)	Higher (e.g., 0.02)
Thermal Stability	Excellent	Moderate
Cost	Higher	Lower

RT-duroid PTFE-based laminates are engineered for precision and reliability in demanding RF and microwave applications. Their unique combination of electrical, mechanical, and thermal properties makes them a superior choice for cutting-edge technologies in aerospace, telecommunications, and beyond