F4BM275 RF/Microwave Double-sided copper-clad Laminate and fabricate 2-layer 60mil thick PCB Solutions

Product Description

F4BM275 is a high-performance PTFE-based laminate from the F4BM series, engineered for microwave and RF applications that demand stable electrical performance, low loss, and cost-effective high-volume manufacturing. The material is produced by scientifically formulating and strictly pressing a combination of fiberglass cloth, polytetrafluoroethylene (PTFE) resin, and PTFE film.

Compared with the earlier F4B family, F4BM offers a wider range of dielectric constants, lower dielectric loss, higher insulation resistance, and improved stability—making it a capable replacement for similar imported materials. F4BM uses electrodeposited (ED) copper foil and is intended for applications where PIM is not a primary requirement. For applications requiring excellent PIM performance, the F4BME variant pairs the same dielectric layer with reverse-treated foil (RTF), providing more precise line control and lower conductor loss.

A key advantage of the F4BM series is its tunable dielectric constant. By adjusting the ratio of PTFE to fiberglass cloth, the Dk can be precisely controlled from 2.17 to 3.0. Higher Dk values correspond to a higher glass content, which improves dimensional stability, lowers the coefficient of thermal expansion, and reduces temperature drift—with only a slight increase in dielectric loss.

Key Properties at a Glance (F4BM275):

Applications

1. Microwave, RF, and Radar Systems 
2. Phase Shifters and Passive Components 
3. Power Dividers, Couplers, and Combiners 
4. Feed Networks and Phased Array Antennas 
5. Satellite Communications 
6. Base Station Antennas 

The F4BM series is also available in aluminum-backed or copper-backed configurations (F4BM—AL and F4BM—CU) for applications requiring shielding or heat dissipation.

Custom PCB Manufacturing on F4BM275

As a specialized manufacturer of high-frequency printed circuit boards, we offer comprehensive fabrication services using F4BM275 and other advanced laminates. The following specification details a representative 2-layer rigid PCB implementation:

PCB Construction Details:

Precisely Controlled Dielectric Constant:
F4BM275 offers a Dk of 2.75 ±0.05 at 10 GHz, with the broader F4BM series covering 2.17 to 3.0. This range allows designers to select the optimal Dk for impedance matching and circuit miniaturization while maintaining repeatable performance.

Low Dielectric Loss:
With a dissipation factor of 0.0015 at 10 GHz and 0.0021 at 20 GHz, F4BM275 minimizes signal attenuation in high-frequency transmission lines—supporting efficient antenna feed networks and low-loss passive components.

Excellent Dimensional Stability:
The fiberglass-reinforced construction provides good dimensional stability, reducing registration errors during fabrication and supporting tight positional tolerances. Higher-Dk variants in the series offer even greater glass content for improved stability and lower CTE.

Low Thermal Expansion and Stable Temperature Behavior:
The CTE values of 14 ppm/°C (X), 16 ppm/°C (Y), and 112 ppm/°C (Z) over -55°C to +288°C help maintain mechanical integrity through thermal cycling. The temperature coefficient of Dk (-92 ppm/°C from -55°C to +150°C) ensures stable electrical performance across operating temperature ranges.

Thermal and Environmental Durability:

1. Long-term operating temperature range of -55°C to +260°C
2. Thermal conductivity of 0.38 W/m·K for heat dissipation
3. Moisture absorption of ≤0.08% for stable performance in humid environments
4. UL 94 V-0 flammability rating

Cost-Effective High-Volume Solution:
F4BM275 is designed for commercial, high-volume production with a favorable cost-performance ratio. It is available in a wide range of standard panel sizes and thicknesses, and custom dimensions can be accommodated on request.

Quality and Availability

All boards are manufactured in compliance with IPC-Class-2 quality standards, ensuring robust reliability for commercial and industrial applications. 100% electrical testing is performed prior to shipment to guarantee functional integrity.

Our production capability extends to worldwide availability, with flexible shipping and logistics support for both prototype and volume requirements. We offer rapid turnaround and competitive pricing while maintaining strict process control.

For inquiries about custom stack-ups, alternative dielectric constants, aluminum or copper backing, panel sizes, or other configurations, please contact our sales engineering team—we are ready to support your high-frequency circuit board requirements.