Introduction to Rogers CuClad 217

Rogers CuClad 217 is a ceramic-filled thermoset laminate material designed for performance-driven high frequency printed circuit boards. With a stable dielectric constant of 2.17, it provides consistent electrical performance through microwave and mm-wave frequencies.

Key features of Rogers CuClad 217 include:

• Low and stable dielectric constant of 2.17
• Low loss for high frequency efficiency
• High thermal conductivity for heat dissipation
• Low Z-axis expansion for reliability
• UL 94V-0 flammability rating
• Compatible with standard PCB processes

With its precision dielectric properties and reliability, CuClad 217 allows designers to achieve the electrical performance needed for RF systems operating above 10 GHz.

Rogers CuClad 217 Material Properties

Rogers CuClad 217 possesses unique material attributes that facilitate the design and fabrication of high frequency PCBs:

Stable Dielectric Constant

• Dielectric constant of 2.17 ± 0.02
• Consistent across frequency range
• Allows precision impedance control

Low Loss Tangent

• Loss tangent of 0.0009 at 10 GHz
• High frequency efficiency and signal integrity

Thermal Conductivity

• 0.67 W/mK thermal conductivity
• Dissipates heat from high power circuits

Low Z-axis CTE

• 20 ppm/°C coefficient of thermal expansion
• Reduces risk of reliability failures

UL 94V-0 Flammability Rating

• Meets UL 94V-0 requirements at 0.062”
• Excellent fire safety rating

Key Material Properties Summary

Property	Value
Dielectric Constant	2.17 ± 0.02
Loss Tangent	0.0009 at 10 GHz
CTE Z-axis	20 ppm/°C
Thermal Conductivity	0.67 W/mK
UL 94 Rating	V-0 at 0.062″

Rogers CuClad 217 Laminate Copper Cladding

Rogers CuClad 217 materials are clad with electrodeposited copper foil, available in different weights:

• Standard 1⁄2 or 1 oz copper foil
• Heavier 2 or 3 oz foils for high current capacity
• Low profile foils for reduced conductor losses
• Reverse treat and double treat foils for high bond strength

Copper alloy foils are also available for even greater adhesion and stiffness. The copper foil type can be specified based on electrical, thermal, and mechanical requirements.

PCB Design with Rogers CuClad 217

To achieve maximum performance with Rogers CuClad 217 laminates, RF PCBs should be designed with the following considerations:

Controlled Impedances

• Match trace impedances to 50Ω or 75Ω system impedance
• Account for Dk tolerance over temperature
• Simulate across full operating frequency range

Minimize Conductor Losses

• Use thicker copper weights where allowed
• Minimize number of vias and small drill sizes
• Smooth surface finish recommended

Thermal Management

• Sufficient thermal vias under components
• Backside metallization for groundplane heat sinking
• Avoid excessive thermal gradients

Signal Integrity

• Careful component layout and isolation
• Treat discontinuities and transitions
• Model to identify resonant frequencies

Prototyping and testing helps validate the RF performance prior to release for production.

PCB Fabrication with Rogers CuClad 217

Rogers CuClad 217 laminates are fully compatible with standard PCB processing methods:

Imaging and Etching

• Compatible with most liquid photo resists
• Can be etched in cupric chloride or ammoniacal etchants

Hole Drilling

• Use mechanical, punch, or laser drilling
• Plasma etching available for fine features

Plating and Outerlayer Lamination

• Electroless copper or direct metallization plating
• Standard lamination methods with RCC materials

Final Finishes

• Immersion silver, immersion tin, ENIG, OSP, and HASL

Rogers provides additional guidelines for optimal fabrication results.

Rogers CuClad 217 Material Availability

Rogers CuClad 217 laminates are offered under the RO2203TM and RO3203TM product designations with the following standard offerings:

Material	Description
RO2203 (2)	0.002” dielectric
RO2203 (5)	0.005” dielectric
RO2203 (10)	0.010” dielectric
RO2203 (20)	0.020” dielectric
RO3203 (10)	0.010” dielectric
RO3203 (20)	0.020” dielectric

• Sheet sizes up to 18” x 24”
• Cut to customer requirements
• Prepregs available for multilayer designs

Rogers CuClad 217 Laminate Applications

The stable electrical performance and microwave reliability make Rogers CuClad 217 suitable for many high frequency and high reliability PCB applications:

Aerospace and Defense

• Radar systems
• Electronic warfare boards
• Satellite payloads
• Missile guidance

Test and Measurement

• Oscilloscopes, signal generators, analyzers
• ATE test fixtures
• Probes and calibration boards

Wireless Infrastructure

• 5G mmWave antenna arrays
• Microwave backhaul radios
• Small cell networks

High Speed Digital

• Data processing boards
• High speed serial interfaces
• Low-loss power distribution

Considerations for Using Rogers CuClad 217

While providing many benefits, there are some factors to consider when selecting Rogers CuClad 217 material:

• Higher cost than standard FR-4 laminates
• Processing may require tighter controls
• Lead times typically longer than FR-4
• Susceptible to shrinkage if not properly handled
• Not compatible with pressing or wave soldering

For many advanced microwave PCBs, Rogers CuClad 217 delivers the performance and reliability needed to meet demanding application requirements.

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Frequently Asked Questions

What is the flammability rating of Rogers CuClad 217 laminates?

Rogers CuClad 217 laminates achieve a UL 94 V-0 flammability rating at a thickness of 0.062” (1.57mm). This makes the material suitable for many applications requiring a V-0 safety certification.

What are the bondply materials used with Rogers CuClad 217 prepregs?

Rogers offers RCC and RCCTM prepregs for use with CuClad 217 core materials to produce multilayer boards. These advanced dielectric materials provide outstanding thermal, mechanical, and electrical properties.

Can Rogers CuClad 217 laminates withstand lead-free soldering processes?

Yes, Rogers CuClad 217 laminates have a high Tg of >280°C which allows them to reliably withstand lead-free soldering methods, including reflow and wave soldering up to 260°C peak temperatures.

What type of signal loss occurs in Rogers CuClad 217 at high frequencies?

At microwave frequencies, the primary signal losses in Rogers CuClad 217 are due to dielectric loss and conductor loss. Dielectric loss is minimized by the low loss tangent, while conductor losses can be reduced through proper trace design.

Does Rogers CuClad 217 require special chemical solutions compared to standard FR-4 processing?

No, standard chemical solutions used for most laminates are compatible with Rogers CuClad 217. This includes ammoniacal and cupric chloride etchants, alkaline developers, copper and solder plating chemistries.