How to Enhance RF PCB Performance with RO4350B and RO4450F Material Combination?

May 10, 2025

In radio frequency (RF) and microwave circuit design, PCB performance directly determines signal transmission quality and system reliability. The 8-layer HDI RF PCB combining Rogers RO4350B and RO4450F materials has become an ideal choice for high-end applications due to its excellent electrical performance and manufacturing convenience.

1.Superior Material Properties

RO4350B is a glass fiber-reinforced hydrocarbon/ceramic composite material that combines the low-loss characteristics of PTFE with the ease of processing of epoxy resin. Its dielectric constant (Dk) remains stable at 3.48±0.05, with a dissipation factor as low as 0.0037, making it highly suitable for high-frequency signal transmission. Additionally, RO4350B's coefficient of thermal expansion (CTE) closely matches that of copper, ensuring outstanding dimensional stability and reliable via quality, even under harsh thermal shock conditions.

RO4450F serves as the bonding layer for multilayer boards, featuring a high glass transition temperature (Tg) and supporting multiple lamination cycles. It is fully compatible with RO4350B, further enhancing the reliability and signal integrity of multilayer PCBs.

2.Precision Design and Manufacturing

This 8-layer HDI PCB employs high-density interconnect (HDI) technology, with a minimum trace width/spacing of 4/6 mil and a minimum via diameter of 0.4mm. Blind via designs (e.g., GTL-L7, L3-GBL, etc.) enable complex routing. With a board thickness of 1.8mm and strict impedance control, it ensures consistent 50-ohm signal transmission. The surface is treated with electroless nickel immersion gold (ENIG), providing excellent solderability and oxidation resistance.

3.road Application Scenarios

Thanks to its low-loss characteristics and high stability, this PCB is particularly well-suited for high-frequency applications such as:
- Cellular base station antennas and power amplifiers
- Automotive radar and sensors
- Low-noise blocks (LNB) for satellite communications
- Radio frequency identification (RFID) tags

4.Quality and Reliability

The PCB complies with IPC-Class-2 standards, with all vias resin-filled and capped, and undergoes 100% electrical testing to ensure out-of-factory quality. RO4350B's high Tg value (>280°C) and low water absorption rate (0.06%) further guarantee long-term reliability in harsh operating environments.

5. Conclusion

The combination of Rogers RO4350B and RO4450F provides a high-performance, highly reliable solution for RF designs. Whether for complex multilayer routing or high-frequency signal transmission, this 8-layer HDI PCB meets stringent requirements, making it the premier choice for engineers in the RF field.