What is Rogers 4350B ?

 

Overview of Rogers 4350B High Frequency Laminate

Rogers 4350B is a circuit board material designed for high frequency, high performance printed circuit board (PCB) applications. It has excellent electrical performance combined with high thermal conductivity.

Some key properties of Rogers 4350B include:

• Dielectric constant of 3.48
• Low loss tangent of 0.0037
• High thermal conductivity of 1.1 W/m/K
• Compatible with lead-free assembly
• UL 94V-0 flammability rating

It is part of Rogers Corporation's RO4000® series of high frequency circuit laminates and offers an excellent balance of electrical, thermal, and cost qualities.

In the sections below, we'll cover Rogers 4350B in more detail including its properties, key features, design guidelines, typical applications and comparisons to similar PCB materials.

Properties of Rogers 4350B Circuit Board Material

Rogers 4350B possesses specialized properties that make it well suited for use in high frequency, high speed, and high power PCB designs:

Electrical Properties

• Stable dielectric constant of 3.48 ±0.05 over frequency
• Low loss tangent of 0.0037 measured at 10 GHz
• Tight dielectric constant tolerance of ±0.05
• Maximum operating frequency >30 GHz
• Controlled impedance suitable for stripline transmission lines
• Low signal loss for long transmission line traces

Thermal Properties

• High thermal conductivity of 1.1 W/m/K
• X & Y coefficient of thermal expansion (CTE) of 13 ppm/°C
• Z axis CTE of 29 ppm/°C
• Glass transition temperature of >280°C

Physical Properties

• Standard thickness from 0.020" (0.5mm) to 0.062" (1.6mm)
• Excellent dimensional stability with thickness tolerance ±10%
• Good flexural strength >2,450 kg/cm2
• Water absorption (24 hr immersion) of <0.2%
• Smooth surface finishes achievable

Key Features & Benefits of Rogers 4350B

Rogers 4350B has several standout features that enable improved performance, easier PCB integration and reliable functionality:

Loaded Dielectric Layer - The dielectric resin system is heavily loaded with ceramic fillers to enhance electrical and thermal performance. This distinguishes it from most standard circuit board laminates.

High Thermal Conductivity - With thermal conductivity of 1.1 W/m/K in the X-Y direction, Rogers 4350B conducts heat efficiently from hot components to help stabilize operating temperatures. This supports increased power handling.

Low EMI & Radiation - Tightly controlled electrical properties contain internal signal propagation and minimize undesirable emissions that can interfere with other devices. This makes Rogers 4350B suitable for sensitive communication systems.

Lead-Free Assembly Compatible - Rogers 4350B allows processing with standard lead-free assembly and soldering methods like SAC305 solder. This eases manufacturing for modern electronics.

UL 94V-0 Flammability Rating - Meets UL 94 vertical burn test criteria for circuit board materials, making it suitable for consumer and industrial electronics safety compliance.

ITAR Registration - Rogers 4350B is registered under the United States Munitions List (USML) Category XI and International Traffic in Arms Regulations (ITAR). This allows usage in defense related applications with proper export licensing.

PCB Design Considerations with Rogers 4350B

To fully realize the potential benefits of Rogers 4350B during circuit design and layout, engineers should keep several guidelines in mind:

Account for Anisotropic Material Properties

• The dielectric constant and loss tangent is different in the Z-axis versus the X/Y plane
• Thermal conductivity is higher in plane than in the Z direction
• Adjust circuit models and stacks accordingly

Leverage Thermal Capabilities

• Incorporate thermal vias and internal power planes connected to heat sources
• Use impedance matched metal core boards or thermal clads if more heat dissipation is needed

Maintain Adequate Spacing

• High dielectric constant allows tighter routing & spacing but ensure design rules are followed
• Account for typical PCB fabrication capabilities based on circuit density

Model Electrical Performance

• Use 3D EM simulation software to model high frequency or high speed behavior
• Verify acceptable loss, efficiency, eye diagrams over typical PCB manufacturing tolerances

Focus on Signal Integrity

• Match trace widths & spacing to achieve target impedance
• Minimize discontinuities, stubs, & acute angle turns

Typical Applications of Rogers 4350B

The balanced electrical and thermal properties of Rogers 4350B make it a common choice for high complexity and performance PCB designs like:

Aerospace & Defense Electronics

• Radar modules
• Electronic warfare systems
• Avionics control boards
• Beamforming networks
• Missile guidance systems

5G Telecommunication Circuits

• 5G NR remote radio heads
• Active antenna arrays
• 28+ GHz mmWave boards
• Distributed antenna system PCBs

High Speed Digital Designs

• Processor & memory interfaces
• High density interconnects
• SERDES communication links
• Optical networking PCBs

Microwave & RF Boards

• Satellite communication
• Radar front-ends
• Software defined radios
• Wireless infrastructure

Automotive Electronics

• Vehicle radar modules
• LiDAR control electronics
• Ultra wideband radar sensors
• Vehicle-to-vehicle (V2V) systems

Comparison to Other High Frequency Materials

Rogers 4350B fills a niche between general purpose microwave laminates like RO4003C and more premium performance materials. Here is how it compares:

Material	Dielectric Constant	Loss Tangent	Thermal Conductivity	Relative Cost
RO4003C	3.38	0.0027	0.35 W/m/K	Low
Rogers 4350B	3.48	0.0037	1.1 W/m/K	Moderate
RO4835	3.54	0.0031	0.84 W/m/K	High
RT/duroid 6002	2.94	0.0012	0.51 W/m/K	Very High

Rogers 4350B offers:

• Superior performance to RO4003C
• Higher thermal conductivity than RO4003C
• Lower cost compared to premium materials like RT/duroid 6002

This combination of electrical, thermal, and cost factors make Rogers 4350B a versatile choice usable across a wide range of challenging RF PCB applications.

Rogers 4350B Material Availability

Rogers 4350B is available worldwide through authorized Rogers distribution partners. Standard panels sizes are 18" x 24" (457 mm x 610mm) for prototype quantities. For production volumes, larger panel sizes are possible for improved fabrication yield. The table below summarizes common product variations:

Variant	Dielectric Thickness	Copper Cladding
4350B2	0.020" (0.5mm)	1⁄2 oz. (18 μm) electrodeposited copper foil
4350B3	0.030" (0.75mm)	1 oz. (35 μm) electrodeposited copper foil
4350B4	0.040" (1 mm)	1 oz. (35 μm) electrodeposited copper foil
4350B6	0.060" (1.5mm)	1 oz. (35 μm) electrodeposited copper foil

Contact Rogers Corporation or authorized distributors for detailed ordering information, pricing, inventory availability, and lead times.

Rogers 4350B High Frequency Laminate FAQs

Q: Is Rogers 4350B compatible with standard PCB processing?

A: Yes, Rogers 4350B allows processing using standard FR-4 PCB fabrication, assembly, and soldering methods. Additional considerations may be required for more advanced boards with fine features due to the higher dielectric constant.

Q: Can Rogers 4350B be used for multilayer PCB designs?

A: Definitely, the RO4350B bondply material variant facilitates multilayer, high layer count PCB designs needing strong thermal management capabilities.

Q: What finish plating can be used with Rogers 4350B?

A: Common PCB plating like Immersion Silver (IAg), Immersion Tin (ISn), Electroless Nickel Immersion Gold (ENIG) and Organic Solderability Preservative (OSP) can be used for Rogers 4350B processing.

Q: Does Rogers 4350B laminate require special storage or handling?

A: Rogers 4350B has no special storage or handling requirements beyond that of typical PCB materials. It should