4-Layer RO4350B PCB with S1000-2M – High-Frequency, Low-Loss Circuit Boards for RF and Microwave Applications

Introduction:

In the world of high-frequency electronics, 4-layer PCBs are the backbone of cutting-edge designs, enabling everything from radar systems to millimeter-wave applications. At Bicheng, we’ve developed a 4-layer PCB using RO4350B and S1000-2M materials, designed to deliver exceptional performance, reliability, and cost-effectiveness. Whether you’re working on commercial airline broadband antennas or point-to-point digital radio systems, our PCBs are built to meet the most demanding requirements.

Product Specifications and Features:

1. Introduction of RO4350B:

Rogers RO4350B materials are proprietary woven glass-reinforced hydrocarbon/ceramics with electrical performance close to PTFE/woven glass and the manufacturability of epoxy/glass. RO4350B laminates provide tight control on dielectric constant (Dk) and maintain low loss while utilizing the same processing methods as standard epoxy/glass. Available at a fraction of the cost of conventional microwave laminates, RO4350B laminates do not require special through-hole treatments or handling procedures like PTFE-based materials. These materials are UL 94 V-0 rated, making them ideal for active devices and high-power RF designs.

RO4350B material's thermal coefficient of expansion (CTE) provides several key benefits to the circuit designer. The expansion coefficient of RO4350B material is similar to that of copper, which allows the material to exhibit excellent dimensional stability—a property needed for mixed dielectric multi-layer board constructions. The low Z-axis CTE of RO4350B laminates provides reliable plated through-hole quality, even in severe thermal shock applications. RO4350B material has a Tg of >280°C (536°F), so its expansion characteristics remain stable over the entire range of circuit processing temperatures.

2. Key Features of RO4350B:

• Dielectric Constant (Dk): 3.48 ±0.05 at 10GHz/23°C.
• Dissipation Factor (Df): 0.0037 at 10GHz/23°C.
• Thermal Conductivity: 0.69 W/m/°K.
• CTE: X-axis 10 ppm/°C, Y-axis 12 ppm/°C, Z-axis 32 ppm/°C.
• High Tg: >280°C.
• Low Water Absorption: 0.06%.

3. Key Features of S1000-2M:

• Lower Z-Axis CTE for improved through-hole reliability.
• Excellent mechanical processability and thermal resistance.
• Lead-free compatible.
• Tg 180°C (DSC), UV blocking/AOI compatible.
• High heat resistance.
• Excellent Anti-CAF performance.
• Low water absorption.

PCB Construction Details:

1. PCB Stack-up:

• Copper Layer 1: 35 µm.
• RO4350B Core: 0.254 mm (10 mil).
• Copper Layer 2: 35 µm.
• Prepreg: 1080 RC63%, 0.0644 mm (2.5 mil).
• Copper Layer 3: 35 µm.
• S1000-2M Core: 1.1 mm (43 mil).
• Copper Layer 4: 35 µm.

2. PCB Construction Details:

• Board Dimensions: 90mm x 95mm = 1 PCS, ±0.15mm.
• Minimum Trace/Space: 5/4 mils.
• Minimum Hole Size: 0.35mm.
• No Blind Vias.
• Finished Board Thickness: 1.6mm.
• Finished Cu Weight: 1 oz (1.4 mils) inner/outer layers.
• Via Plating Thickness: 20 µm.
• Surface Finish: Electroless Nickel Immersion Gold (ENIG).
• Top Silkscreen: White.
• Bottom Silkscreen: No.
• Top Solder Mask: Green.
• Bottom Solder Mask: No.
• Impedance Control: 50Ω on 5mil/9mil traces/gaps (top layer).
• Edge Plating: Applied on designated areas.
• Via Filling and Capping: 0.35mm vias filled and capped.
• Electrical Testing: 100% tested prior to shipment.

3. PCB Statistics:

• Components: 33.
• Total Pads: 242.
• Thru-Hole Pads: 125.
• Top SMT Pads: 117.
• Bottom SMT Pads: 0.
• Vias: 49.
• Nets: 3.

Advantages of the Product:

1. High-Frequency Performance: RO4350B ensures low signal loss and stable Dk, making it ideal for RF and microwave applications.
2. Thermal Stability: Both materials offer high Tg and excellent thermal resistance, ensuring reliability in high-temperature environments.
3. Cost-Effective: RO4350B provides PTFE-like performance at a fraction of the cost.
4. Ease of Manufacturing: Compatible with standard epoxy/glass processes, reducing production complexity.
5. Durability: Edge plating, via filling, and ENIG finish enhance mechanical and electrical reliability.

6. Disadvantages of the Product:

7. Limited Layer Count: 4 layers may not suffice for extremely complex designs requiring higher layer counts.
8. No Blind/Buried Vias: Not suitable for designs requiring advanced via structures.
9. IPC-Class-2 Standard: While reliable, it may not meet the stringent requirements of mission-critical applications (IPC-Class-3).

Typical Applications:

• Commercial Airline Broadband Antennas: Ensures reliable connectivity at high frequencies.
• Microstrip and Stripline Circuits: Ideal for high-frequency signal routing.
• Millimeter Wave Applications: Delivers low loss and stable performance.
• Radar and Guidance Systems: Provides the reliability needed for critical systems.
• Point-to-Point Digital Radio Antennas: Ensures high-speed data transmission.

Why Choose Us?

At Bicheng, we combine advanced materials, precision engineering, and rigorous testing to deliver PCBs that meet your exact needs. Our 4-layer PCBs with RO4350B and S1000-2M are designed to perform in the most demanding environments, offering a perfect balance of performance, reliability, and cost-effectiveness.

Conclusion:

Our 4-layer PCBs with RO4350B and S1000-2M are the ideal solution for high-frequency, high-reliability applications. With exceptional thermal stability, low signal loss, and ease of manufacturing, these PCBs are built to meet the challenges of modern electronics. Ready to elevate your designs? Contact us today to learn more or request a quote.