F4BM265 PTFE Laminate & Multilayer PCB – 4-Layer, 4.14mm, ENIG, IPC Class 3 for Radar & Satellite RF Applications

F4BM265 PTFE Laminate & Custom Multilayer PCB – Complete Guide

Quick Answer

What is F4BM265?

It's a high-performance PTFE (polytetrafluoroethylene) glass fabric copper-clad laminate with a dielectric constant (Dk) of 2.65 and an ultra-low dissipation factor (Df) of 0.0013 @ 10 GHz. Manufactured by Taizhou Wangling Insulating Materials Factory, it serves as a cost-effective drop-in replacement for imported PTFE substrates in RF/microwave applications.

What PCB can you build with it?

We offer a complete 4-layer multilayer PCB solution based on F4BM265, featuring a 4.14 mm total thickness, 35 µm finished copper, ENIG surface finish, blue solder mask, blind vias, impedance control, and IPC Class 3 reliability — ideal for phased-array radar, satellite communications, and high-power RF systems.

Key Takeaways

1. Material Overview

The F4BM265 is part of the broader F4BM series of PTFE glass fabric laminates, engineered through a scientific formulation of woven glass fabric, PTFE resin, and PTFE film under a rigorous compression molding process. Compared to the standard F4B series, the F4BM series delivers:

Wider DK range (2.17 ~ 3.0, customizable)

Lower dielectric loss across microwave frequencies

Higher insulation resistance

Enhanced dimensional stability through precise PTFE-to-glass ratio control

Superior temperature stability (TCDk: -100 ppm/°C)

2. F4BM vs. F4BME – Which Copper Foil Do You Need?

Bottom Line: Choose F4BM for cost-effective general-purpose RF designs. Choose F4BME when PIM performance, precision etching, and minimal conductor loss are critical.

3. F4BM265 Technical Data Sheet

4. Available Configurations

Copper Foil Options

Panel Sizes

5. Application Fields

- Aerospace equipment, space and cabin equipment

- Microwave, RF

- Radar, military radar

- Feed networks

- Phase-sensitive antennas, phased array antennas

- Satellite communications, and more.

6. Custom Multilayer PCB – Complete Specification

Based on F4BM265, we offer a complete 4-layer PCB solution with the following specifications:

Stack-Up Configuration

Board Specifications

FAQ

Q1: What is the difference between F4BM and F4BME?

A: Both use the same PTFE/glass dielectric, but they differ in copper foil. F4BM uses ED (electrodeposited) copper and is suitable for general RF applications. F4BME uses reverse-treated RTF copper, delivering superior PIM performance (≤ -159 dBc), more precise circuit etching, and lower conductor loss. Choose F4BME for base stations, satellite, or any low-PIM-sensitive system.

Q2: Can I customize the dielectric constant of F4BM material?

A: Yes. The F4BM series supports DK values from 2.17 to 3.0, with custom DK available upon request. Higher DK values are achieved by increasing the glass fabric ratio, which also improves dimensional stability and lowers CTE, though Df may slightly increase.

Q3: What does "total thickness" vs. "dielectric thickness" mean when ordering?

A: When placing an order, you must specify whether your thickness requirement is:

Dielectric thickness – thickness of the PTFE/glass layer only (excluding copper)

Total thickness – thickness including both copper layers

For example, a 0.508 mm total thickness board with 1 oz copper on both sides would have a dielectric thickness of approximately 0.438 mm.

Q4: Can F4BM265 support blind and buried vias?

A: Yes. F4BM265 is compatible with controlled-depth drilling and sequential lamination processes, making it suitable for blind and buried via designs. Our custom 4-layer PCB example includes blind vias for HDI capability.

Q5: What is the maximum panel size available for F4BM265?

A: Standard maximum panel sizes are 1000 × 1200 mm. Custom larger sizes can be discussed. However, note that if the material thickness is ≥4.0mm or ≤0.2mm, the maximum size is limited to 500 × 610 mm due to manufacturing constraints.

Q6: Is F4BM265 suitable for high-power RF applications?

A: Absolutely. With a thermal conductivity of 0.36 W/(m·K) in the Z-direction, an operating temperature range of -55°C to +260°C, and ultra-low dielectric loss, F4BM265 excels in high-power RF applications. For even better thermal management, consider the metal-backed variants (F4BM265-AL or F4BM265-CU).

Q7: Is F4BM265 RoHS-compliant and halogen-free?

A: The material is RoHS-compliant and meets halogen-free requirements. It also achieves UL94 V-0 flame rating for safety compliance.

Q8: What is the typical lead time for custom F4BM265 PCBs?

A: Lead times vary based on complexity and quantity. For standard multilayer boards like the 4-layer design described above, typical lead times range from 10 to 20 working days. Please contact us for specific project timelines.

Q9: Can you provide impedance-controlled PCBs on F4BM265?

A: Yes. We offer full impedance control design and manufacturing support. The stable Dk of 2.65 ±0.05 ensures consistent impedance across the board, and we can provide impedance test coupons with your order.

Q10: Do you offer assembly services for these PCBs?

A: Yes, we provide turnkey PCB assembly services. Please inquire with our sales team for assembly options, component sourcing, and testing services.

Ready to Get Started?

Whether you need F4BM265 raw laminate, a metal-backed variant, or a fully fabricated multilayer PCB with blind vias and impedance control, we are here to help.

Contact us today for:

Material sampling and testing

Custom stack-up design assistance

PCB quoting and DFM review

Technical support for your specific application