10-Layer RO3003 High-Performance RF PCB with Immersion Gold Finish

1. Introduction to Core Technologies

RO3003 Laminate

RO3003 is a high-performance ceramic-filled PTFE-based high-frequency circuit material from Rogers' RO3000 series, developed specifically for commercial microwave and RF applications. Its key characteristics include:

1.Low Dielectric Constant and Loss: The design dielectric constant (Dk) is 3.00±0.04, with a dissipation factor (Df) as low as 0.0010 at 10 GHz, providing excellent signal transmission performance.
2.Outstanding Temperature Stability: The dielectric constant temperature coefficient is as low as -3 ppm/˚C, ensuring stable electrical performance across a wide temperature range.
3.Excellent Thermomechanical Properties: The X/Y-axis coefficient of thermal expansion (CTE) is approximately 17 ppm/°C, well-matched with copper for superior dimensional stability; the Z-axis CTE is 25 ppm/°C, ensuring through-hole reliability even under harsh thermal conditions.
4.High Reliability: With a decomposition temperature as high as 500˚C and a copper peel strength of 12.7 lbs/in, it meets the demands of high-reliability applications

RO3003 material can be manufactured using standard PTFE processing techniques and is suitable for multilayer board designs, allowing the use of materials with different dielectric constants on different layers without causing warpage or reliability issues.

FR-28 Prepreg

FR-28 is one of AGC's fastRise™ series multilayer non-reinforced prepregs, designed specifically for high-density interconnection and high-speed digital/RF circuits. Its features include:

1.Low-Loss Characteristics: At 10 GHz, the typical dielectric constant (Dk) ranges from 2.74 to 2.76, with a dissipation factor (Df) between 0.0010 and 0.0015, helping to reduce signal transmission loss.
2.High Resin Content and Good Fillability: With high resin content, it is suitable for high-layer-count PCB lamination and can effectively fill blind/buried vias and copper surface irregularities.
3.Suitable for Microvia Formation: Recommended for microvia formation and foil lamination processes, with good drilling quality.
4.Broad Compatibility: Bonds well with various materials including PTFE, epoxy, low-flow epoxy, LCP, polyimide, and hydrocarbon materials.

FR-28 Prepreg complies with IPC-4103B/530 standards and is suitable for high-speed digital and RF multilayer boards requiring low loss and high reliability.

2.PCB Details

3.PCB Stackup (10-Layer Rigid Structure)

This board adopts a symmetrical 10-layer structure design with a total pressed thickness of 1.66mm. The layers are alternately composed of RO3003 cores and FR-28 Prepreg, aiming to provide stable impedance control and excellent signal integrity.

Top Layer (L1): Begins with a 0.035mm thick copper layer.
First Dielectric Layer: Below is a 0.127mm thick RO3003 core.
Layer 2 (L2): 0.035mm copper layer.
Second Dielectric Layer: Composed of two layers of FR-28 Prepreg laminated together, total thickness 0.1745mm.
Layer 3 (L3): 0.035mm copper layer.
Third Dielectric Layer: 0.127mm thick RO3003 core.
Layer 4 (L4): 0.035mm copper layer.
Fourth Dielectric Layer: Two layers of FR-28 Prepreg, total thickness 0.1745mm.
Layer 5 (L5): 0.035mm copper layer.
Fifth Dielectric Layer: 0.127mm thick RO3003 core.
Layer 6 (L6): 0.035mm copper layer.
Sixth Dielectric Layer: Two layers of FR-28 Prepreg, total thickness 0.1745mm.
Layer 7 (L7): 0.035mm copper layer.
Seventh Dielectric Layer: 0.127mm thick RO3003 core.
Layer 8 (L8): 0.035mm copper layer.
Eighth Dielectric Layer: Two layers of FR-28 Prepreg, total thickness 0.1745mm.
Layer 9 (L9): 0.035mm copper layer.
Ninth Dielectric Layer: 0.127mm thick RO3003 core.
Bottom Layer (L10): Concludes with a 0.035mm thick copper layer.

Blind via designs connect L7-L10 and L9-L10, enabling high-density interconnection.

4.Typical Applications

Leveraging the excellent high-frequency performance and reliability of the RO3003 and FR-28 material combination, this 10-layer PCB is suitable for the following high-end fields:

Aerospace and Defense Electronics: RF front-ends and processing modules in airborne radar, electronic warfare systems, satellite communication payloads, and navigation equipment.
Communication Infrastructure: 5G/6G millimeter-wave base stations, microwave point-to-point backhaul equipment, phased array antenna elements.
Automotive Radar: 77 GHz and higher frequency automotive millimeter-wave radar for ADAS functions such as adaptive cruise control, automatic emergency braking, and blind spot detection.
High-End Test and Measurement: High-frequency circuit boards in instruments like vector network analyzers, spectrum analyzers, and signal generators.
Medical and Industrial Equipment: High-precision imaging systems, industrial sensors, and RF modules for scientific research.

5.Quality Assurance

Artwork Format: Gerber RS-274-X
Quality Standard: IPC-Class-2
Availability: Worldwide

6.Conclusion

This 10-layer RO3003 PCB combines the advantages of high-performance ceramic-filled PTFE substrates and low-loss prepregs. Through meticulous layer stack-up design and blind via technology, it achieves outstanding RF performance, stable mechanical reliability, and high-density interconnection capabilities. Whether for communication systems pursuing extreme frequencies or for aerospace and automotive radar applications requiring stringent environmental adaptability, it provides a solid and reliable high-frequency circuit solution. Its absence of solder mask and silkscreen further meets specific process requirements for cleanliness and special assembly in certain modules, demonstrating broad application flexibility.