Rogers Corporation’s Radix Printable Dielectric material is an innovative solution for designing high frequency printed circuit boards (PCBs) used in applications like 5G, radar, satellite communications, automotive sensors, and more. This recently introduced material enables engineers to 3D print dielectric substrates with excellent electrical performance up to 70 GHz and beyond.
In this comprehensive guide, we will explore Radix’s features and benefits, how it enables new PCB capabilities, design considerations, and frequently asked questions.
Introduction to Radix Printable Dielectric
Radix is Rogers’ first 3D printable dielectric material developed for use in additive manufacturing of microwave and high frequency PCB substrates. It has the following notable characteristics:
- Designed for fused filament fabrication (FFF) 3D printing
- Thermoplastic polymer system with excellent dimensional stability
- Stable dielectric constant of 2.85 and low loss tangent of 0.0025
- Usable frequency range up to 70 GHz with consistent performance
- Near hermetic properties provides protection against environmental factors
- Allows embedding of conductors and components during printing
- Enables design of complex geometries not possible with conventional methods
This unique material provides circuit designers the ability to 3D print custom substrates with the electrical and mechanical properties needed for high frequency applications. Precision 3D printing eliminates many traditional PCB fabrication limitations.
Benefits and Capabilities of Radix Printable Dielectric
Adopting Radix printable dielectric delivers important advantages over regular PCB substrate materials and manufacturing processes:
Design Freedom
- Complex 3D shapes and cavities
- Vertical interconnects and traces
- Embedded components and conductors
- Conformal surfaces and enclosures
Reliability
- Void-free structures with consistent material properties
- Environmentally protected embedded components
- Mechanical robustness and stability
High Frequency Performance
- Stable dielectric properties up to 70 GHz
- Low loss for improved efficiency
- Excellent dimensional tolerance for precision circuits
Manufacturing Agility
- Fast turnaround with no tooling requirements
- Cost effective short runs and prototyping
- Design to fabrication in hours vs weeks
- Simplified supply chain and inventory
These capabilities make Radix an important solution for cutting-edge microwave and mmWave PCBs for 5G infrastructure, radars, satellite communication, and various sensors for defense, industrial, automotive and other applications.
PCB Design Considerations With Radix Printable Dielectric
Designers should keep the following best practices in mind when working with Radix material:
- Account for shrinkage of about 13% in x/y and 21% in z axis
- Minimum trace width and spacing is 0.20 mm (8 mils)
- Use 60° interior angles to avoid stair stepping effect
- Include vent holes in enclosed cavities to prevent damage during printing
- Captured components require clearance for thermal expansion
- Limit unsupported spans to avoid risk of drooping or breaking
- Radix can be drilled, tapped, polished, plated and assembled like conventional PCBs
Enabling New PCB Capabilities with Radix
Here are some examples of novel PCB capabilities unlocked by Radix printable dielectric:
Embedded Components
Discrete components like resistors, capacitors and ICs can be inserted during printing to embed them within the dielectric. This improves reliability, saves space and prevents tampering.
Multi-Layer Circuits
Printing dielectric and conductive layers sequentially enables fabrication of complex multilayer circuits in one setup. VIAs can connect layers with vertical traces.
Conformal Surfaces
Radix allows printing dielectric and circuits atop irregular, curved surfaces for applications like phased array antennas and enclosures.
Thermal Management
Integrated internal channels or cavities for liquid/air cooling can be 3D printed within the dielectric substrate.
RF Shielding
Radix can be printed around components to provide integrated shielding from electromagnetic interference.
As demonstrated above, Rogers Radix material enables game-changing PCB innovations through the power of 3D printing.
Rogers Radix Material Options
Rogers currently offers two material options for the Radix printable dielectric system – R1000 and R1500:
| Property | R1000 | R1500 |
|---|---|---|
| Dielectric Constant | 2.85 | 2.85 |
| Loss Tangent | 0.0025 | 0.0015 |
| Maximum Use Temperature | 260°C | 260°C |
| Density | 1.56 g/cc | 1.56 g/cc |
| Tensile Strength | 28 MPa | 28 MPa |
| Flexural Strength | 41 MPa | 41 MPa |
| Compressive Strength | 73 MPa | 73 MPa |
| Recommended Conductor | Copper | Copper |
The R1000 material provides the lowest loss tangent of 0.0025 for optimal high frequency performance up to 70 GHz. R1500 achieves even lower loss of 0.0015, enabling use up to 220 GHz for specialized mmWave applications.
Both Radix materials offer outstanding dimensional stability under temperature cycling and humidity exposure. They also adhere well to common 3D printing build plates like aluminum and glass.
Rogers Radix Printable Dielectric – Frequently Asked Questions
Here are some common FAQs about Radix printable dielectric:
What 3D printing process is used for Radix?
Radix is formulated for fused filament fabrication (FFF) printing which uses thermoplastic filament feedstock. It requires a high temp extruder capable of 450°C.
Does Radix require special storage conditions?
Radix filament should be stored in a cool, dry place away from sunlight. Standard storage conditions of 18-25°C and <50% relative humidity are recommended.
What types of circuits is Radix suitable for?
Radix enables high frequency PCBs and antennas from L-band up to 70 GHz including 5G NR mmWave, automotive radar, satellite, and aerospace applications.
Can Radix be printed on existing FFF printers?
Yes, Radix can be printed on many existing high-temp FFF printers with some hardware modifications. A 500°C hot end, heated bed, heated chamber, and filament tracker are required.
What conductive materials can be used with Radix?
Copper is recommended for circuits and traces. Silver, aluminum and conductive inks can also be printed for specialized conductors.
How smooth of a surface finish can be achieved?
The printed surface can be progressively smoothed to < 1 micron roughness through sanding, machining and/or coating processes.
Conclusion
Rogers Corporation’s new Radix printable dielectric material is a game changing technology for designing high frequency PCBs. It enables complex geometries with embedded components not feasible with traditional manufacturing techniques. Early adopters are leveraging Radix today to create advanced 5G NR, SATCOM, radar and sensor circuits with superior electrical and mechanical performance. As material and printer capabilities continue improving, expect wider adoption of Radix across cutting-edge microwave and mmWave applications.
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