18-Layer PCB with Premium RO4350B and RO4450F for Superior High-Frequency Performance

1.Introduction to RO4350B Core and RO4450F Bondply:

Rogers RO4350B materials are proprietary woven glass reinforced hydrocarbon/ceramics that offer electrical performance similar to PTFE/woven glass while maintaining the manufacturability of epoxy/glass. RO4350B laminates ensure tight control over dielectric constant (Dk) and exhibit low loss, utilizing standard epoxy/glass processing methods. These materials are available at a fraction of the cost of traditional microwave laminates and do not require special through-hole treatments or handling procedures like PTFE-based materials. They are UL 94 V-0 rated for active devices and high-power RF applications.

The thermal coefficient of expansion (CTE) of RO4350B material closely matches that of copper, providing excellent dimensional stability, essential for mixed dielectric multi-layer constructions. The low Z-axis CTE ensures reliable plated through-hole quality, even under severe thermal shock conditions. RO4350B material has a glass transition temperature (Tg) of over 280 °C (536 °F), maintaining stable expansion characteristics throughout the entire range of circuit processing temperatures.

RO4450F bondplys are compatible with multi-layer constructions involving RO4000 laminates. A high post-cure Tg makes RO4450F bondply an ideal choice for multi-layer assemblies requiring sequential laminations. Fully cured RO4450F bondplys can withstand multiple lamination cycles. Additionally, FR-4 compatible bonding requirements allow for the combination of RO4450F bondply and low-flow FR-4 bondply in non-homogeneous multi-layer constructions using a single bonding cycle.

RO4450F bondplys are compatible with multi-layer constructions involving RO4000 laminates. A high post-cure Tg makes RO4450F bondply an ideal choice for multi-layer assemblies requiring sequential laminations. Fully cured RO4450F bondplys can withstand multiple lamination cycles. Additionally, FR-4 compatible bonding requirements allow for the combination of RO4450F bondply and low-flow FR-4 bondply in non-homogeneous multi-layer constructions using a single bonding cycle.

2. Features of RO4350B:

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

3. Features of RO4450F:

Dielectric Constant: Dk 3.52 ±0.05 at 10 GHz/23 °C
Dissipation Factor: 0.004 at 10 GHz/23 °C
Thermal Conductivity: 0.65 W/m/°K
X-axis CTE: 19 ppm/°C, Y CTE: 17 ppm/°C, Z CTE: 50 ppm/°C

4. PCB Construction Details:

5. PCB Stackup: 18-layer Rigid PCB

6. PCB Statistics:

Components Count: 651
Total Pads: 779
Through Hole Pads: 338
Top SMT Pads: 262
Bottom SMT Pads: 179
Vias Count: 632
Nets Count: 12

7.ARTWORK AND QUALITY

Type of Artwork Supplied: Gerber RS-274-X
Quality Standard: IPC-Class-2
Availability: Worldwide

8.Typical Applications:

Cellular Base Station Antennas and Power Amplifiers
RF Identification Tags
Automotive Radar and Sensors
LNBs for Direct Broadcast Satellites