Introduction
Printed circuit boards (PCBs) designed for high frequency applications require substrate materials with stable dielectric properties and low loss. Rogers RT/Duroid 6002 is a glass microfiber reinforced PTFE composite material engineered to provide tightly controlled performance for microwave and radio frequency PCBs.
This article provides an in-depth look at the characteristics, properties, applications and benefits of the Rogers RT/Duroid 6002 high frequency circuit material.
What is Rogers RT/Duroid 6002?
Rogers RT/Duroid 6002 (RO6002) is a ceramic filled PTFE composite material developed by Rogers Corporation specifically for fabricating microwave PCBs operating up to gigahertz frequencies.
Some key attributes of this material include:
- Low and stable dielectric constant of 2.94 ±0.04
- Low dissipation factor of 0.0012
- Woven E-glass reinforcement for dimensional stability
- High thermal conductivity for heat dissipation
- Lead-free compatible and RoHS compliant
- UL 94V-0 fire rating
- Excellent corona resistance
- Withstands soldering temperatures up to 288°C
- Halogen-free (low chlorine and bromine content)
- Sheet thicknesses from 0.05 mm to 3.18 mm
With these electrical, mechanical and thermal properties, RT/Duroid 6002 provides an optimal substrate choice for microwave circuits and antennas.
Dielectric Properties
The dielectric characteristics of Rogers 6002 make it suitable for high frequency RF and microwave applications:
Dielectric Constant
- Stable dielectric constant of 2.94 ±0.04 up to 10 GHz
- Nearly constant over wide frequency range
Loss Tangent
- Low loss tangent of 0.0012 at 10 GHz
- Enables high Q factors for RF circuits
Moisture Absorption
- Low moisture absorption of 0.02%
- Helps maintain stable dielectric constant
Coefficient of Thermal Expansion
- X and Y axis CTE of 16 ppm/°C
- Z axis CTE of 25 ppm/°C
- Matched to that of copper for reliability
These properties allow the PCB substrate to behave predictably as an electrical insulator up to microwave frequencies.
Mechanical Characteristics
Rogers 6002 combines the attributes of PTFE and glass fabric reinforcement to offer good mechanical characteristics:
- High flexural strength of 24 MPa
- Tensile modulus of 1240 MPa minimizes dimensional changes under temperature fluctuations
- Dense and uniform morphology with consistent dielectric properties throughout the material
- Lead-free soldering compatible with high melting point of 327°C
- Withstands multiple reflow cycles without damage
- Low z-axis CTE reduces stresses between copper and dielectric
The woven glass microfiber reinforcement raises the mechanical strength and stiffness compared to unfilled PTFE.
Thermal Properties
The ceramic filling and glass threads in 6002 provide enhanced thermal conductivity compared to unreinforced PTFE:
- Thermal conductivity of 0.69 W/mK
- Dissipates heat efficiently from copper traces carrying high frequency currents
The higher thermal conductivity prevents localized hot spots and reduces electrical losses.
Common Designations
Rogers RT/Duroid 6002 material is also available under variants like:
- RO6002
- RO6002A
- RO6002B
The different suffixes indicate:
- RO6002A is tested for corona resistance
- RO6002B is a halogen-free version
But otherwise the base properties remain similar to standard 6002.
PCB Fabrication Guidelines
Rogers provides specific fabrication guidelines when using their RF materials which should be followed:
- Allow ±0.05 mm thickness tolerance
- Ensure chemical compatibility if combining with other prepreg or bonding materials
- Limit unsupported copper spans between dielectric layers
- Use redundant thermal vias for heat dissipation from copper layers
- Ensure sufficient prepreg squeeze out during lamination
- Use two-stage lamination process for boards thicker than 2.5 mm
- Allow for 0.8% z-axis shrinkage during lamination
Following these recommendations results in optimal microwave PCB performance.
Typical Applications
Rogers RT/Duroid 6002 is commonly used for PCBs operating from 1 GHz to over 30 GHz including:
- Ku/Ka-Band satellite communication
- 4G/5G cellular base stations
- Microwave radio relays
- Aircraft collision avoidance radar
- Military electronic countermeasures
- Medical radiology equipment
- High energy physics instrumentation
- Automotive radar and sensors
- High frequency circuit substrates
The stable electrical properties and low loss make 6002 well-suited for these microwave and millimeter wave applications.
Availability
Rogers RT/Duroid 6002 is available globally through distributors of Rogers materials or directly from Rogers Corporation. It is widely offered in sheet sizes up to 18×24 inches and thickness ranging from 0.05 mm to 3.18 mm.
Benefits of Rogers RT/Duroid 6002
Rogers 6002 provides these advantages for RF and microwave PCB fabrication:
- Precisely controlled dielectric constant for accurate impedance
- Low loss tangent to reduce signal attenuation
- Tight dielectric tolerances improve circuit performance
- Lead-free compatibility allows soldering without degradation
- Reinforced construction gives dimensional stability
- High thermal conductivity prevents hot spots
- Widespread availability in microwave industry
- Cost advantage compared to PTFE substrates
So Rogers 6002 delivers an optimal combination of electrical, thermal and mechanical properties for high frequency PCB applications from L-band to Ku/Ka-band frequencies.
Conclusion
Rogers RT/Duroid 6002 is an advanced glass reinforced PTFE composite engineered specifically to meet the needs of microwave and radio frequency circuit boards. The precisely controlled dielectric constant and low loss properties enable excellent electrical performance up to Ku-band frequencies. 6002 provides an ideal substrate choice for radar, satellite communication, 5G and other RF systems demanding stable, low loss PCBs. The material’s characteristics make it one of the most popular microwave laminates used widely across commercial and defense applications.
Frequently Asked Questions
Can Rogers 6002 be processed using standard PCB methods?
Yes, Rogers 6002 can be fabricated using typical FR4 PCB manufacturing techniques like etching, drilling, plating, lamination etc. No exotic processes are required.
What copper foil thickness is usually used with Rogers 6002?
1⁄2 oz to 2 oz copper foil is typical for microwave circuits on Rogers 6002 material. 1 oz provides a good balance for moderate RF current handling needs.
Does Rogers 6002 require special storage conditions?
No special storage precautions are needed. Rogers 6002 has indefinite shelf life at room temperature before PCB fabrication compared to some other microwave laminates.
Can Rogers 6002 be combined with FR4 in a multilayer board?
Yes, Rogers 6002 layers can be interleaved with properly selected FR4 prepregs to create hybrid multilayer boards. But large Dk differences between layers is not recommended.
What are the pros and cons versus RT Duroid 5880 as an RF laminate?
RT/Duroid 6002 has slightly lower loss while 5880 allows finer lines and spaces. But both provide excellent microwave PCB performance and choice depends on specific design needs.
