Wangling's F4BTM298 High-DK PTFE Laminate with ED copper foil

Product Description

What is F4BTM298?

 

It is a high-dielectric-constant PTFE laminate manufactured by Taizhou Wangling Insulating Materials Factory. It is reinforced with glass fiber cloth. It contains nano-ceramic fillers. The dielectric constant (Dk) is 2.98 ±0.06 at 10 GHz. The dissipation factor (Df) is 0.0018 at 10 GHz. The material has a CTE of 15/16 ppm/°C in the X/Y axes. The Z-axis CTE is 78 ppm/°C. The decomposition temperature (Td) is not specified but the material operates from -55°C to +260°C. The material is UL94 V-0 rated. It has very low moisture absorption (0.05%). It is ideal for RF and microwave applications that require higher Dk than standard PTFE materials.

 

 

What PCB can be built with it?

 

A complete 2-layer RF PCB solution can be provided. The board is based on F4BTM298 material. The finished thickness is 0.3 mm. The copper weight is 1 oz per layer. Immersion gold is applied as the surface finish. Black solder mask is applied on the top layer. White silkscreen is printed on the top layer. No solder mask or silkscreen is applied on the bottom layer. The minimum trace and space are 6 and 9 mils. The minimum hole size is 0.4 mm. Via plating thickness is 20 µm. The quality standard is IPC Class 2. This board is ideal for microwave/RF systems, phase shifters, power dividers, couplers, combiners, feed networks, phased array antennas, and satellite communications.

 

 

1. Material Overview

The F4BTM298 is a high-dielectric-constant PTFE laminate. It is manufactured by Taizhou Wangling Insulating Materials Factory. It is reinforced with glass fiber cloth. It contains nano-ceramic fillers. The material is part of the F4BTM series. This series is based on the F4BM dielectric layer. High-dielectric and low-loss nano-ceramics are added.

 

This results in several improvements:

 

Higher dielectric constant

 

Improved heat resistance

 

Lower thermal expansion coefficient

 

Higher insulation resistance

 

Better thermal conductivity

 

Low loss characteristics are maintained

 

 

Key Features of F4BTM298:

Feature	Value/Benefit
High Dielectric Constant	Dk 2.98 ±0.06 – higher than standard PTFE
Low Loss	Df 0.0018 at 10 GHz – minimizes signal attenuation
Nano-Ceramic Filled	Improved thermal and mechanical properties
Low CTE	X/Y: 15/16 ppm/°C – excellent dimensional stability
Low Moisture Absorption	0.05% – stable in humid environments
Wide Operating Range	-55°C to +260°C – suitable for harsh environments
Radiation Resistance	Suitable for space applications
Low Outgassing	Suitable for vacuum environments

 

 

2. F4BTM298 Technical Data Sheet

Property	Test Condition	Unit	F4BTM298 / F4BTME298 Value
Dielectric Constant (Typical)	10 GHz	—	2.98
DK Tolerance	—	—	±0.06
Dissipation Factor (Typical)	10 GHz	—	0.0018
	20 GHz	—	0.0023
TCDk	-55°C to 150°C	ppm/°C	-78
Peel Strength (1 oz F4BTM / ED)	—	N/mm	>1.6
(1 oz F4BTME / RTF)	—	N/mm	>1.4
Volume Resistivity	Normal condition	MΩ·cm	≥1×10⁷
Surface Resistivity	Normal condition	MΩ	≥1×10⁶
Electrical Strength (Z-direction)	5 kW, 500 V/s	kV/mm	>26
Breakdown Voltage (X/Y-direction)	5 kW, 500 V/s	kV	>34
CTE X-axis	-55°C to 288°C	ppm/°C	15
CTE Y-axis	-55°C to 288°C	ppm/°C	16
CTE Z-axis	-55°C to 288°C	ppm/°C	78
Thermal Stress	260°C, 10s, 3 times	—	No delamination
Water Absorption	20±2°C, 24 hours	%	≤0.05
Density	Normal temperature	g/cm³	2.25
Long-term Service Temperature	—	°C	-55 to +260
Thermal Conductivity	Z-direction	W/(m·K)	0.42
PIM Value (F4BTME only)	—	dBc	≤ -160
Flammability	UL94	Rating	V-0
Composition	—	—	PTFE + Glass Fiber Cloth + Nano-Ceramics

 

 

 

3. Application Fields

- Microwave, RF, and radar systems

- Phase shifters

- Power dividers, couplers, combiners

- Feed networks

- Phase-sensitive antennas, phased array antennas

- Satellite communications

- Base station antennas

 

 

4. Custom 2-Layer RF PCB – Complete Specification

A complete 2-layer RF PCB solution can be provided based on F4BTM298. The specifications are shown below.

 

 

Board Specifications

Specification	Detail
Board Type	2-Layer RF PCB
Base Material	F4BTM298 (0.254 mm / 10 mil core)
Finished Board Thickness	0.3 mm
Finished Copper Weight	1 oz (35 µm) per layer
Board Dimensions	109 × 54.5 mm (1 piece)
Dimension Tolerance	±0.15 mm
Minimum Trace / Space	6 / 9 mils
Minimum Hole Size	0.4 mm
Via Plating Thickness	20 µm
Surface Finish	Immersion Gold (ENIG)
Top Solder Mask	Black
Bottom Solder Mask	No
Top Silkscreen	White
Bottom Silkscreen	No
IPC Classification	Class 2
Artwork Format	Gerber RS-274-X
Testing	100% Electrical Test (before shipment)
Availability	Worldwide

 

 

5. Key Benefits of This PCB Design

Feature	Benefit
2-layer RF design is used	Simple and cost-effective RF circuit implementation is achieved
F4BTM298 core (0.254 mm) is used	High Dk (2.98) allows compact designs; low loss (0.0018) ensures signal integrity
Thin 0.3 mm board	Lightweight and compact design is achieved
6/9 mil trace and space are used	Fine-line, high-density RF circuits can be produced
Black solder mask is applied on top	Professional appearance; top-layer circuits are protected
No solder mask on bottom	Thermal dissipation is improved; grounding strategies are enabled
Immersion gold finish is applied	Excellent solderability; oxidation resistance; flat surface
20 µm via plating is used	Reliable plated through-hole connections are ensured
IPC Class 2 quality is met	Commercial and industrial quality standards are satisfied
100% electrical test is performed	Functional integrity is guaranteed before shipment

 

 

 

Q1: What is the dielectric constant of F4BTM298?

The Dk is 2.98 ±0.06 at 10 GHz. This is higher than standard PTFE materials. It allows more compact circuit designs.

 

 

Q2: What is the difference between F4BTM298 and F4BTME298?

Both use the same dielectric layer. They differ in copper foil type:

 

F4BTM298 uses ED copper foil. It is suitable for general RF applications without PIM requirements.

 

F4BTME298 uses reverse-treated RTF copper foil. It offers superior PIM performance (≤ -160 dBc), more precise etching, and lower conductor loss.

 

Choose F4BTME298 for base stations, satellite systems, and low-PIM-sensitive applications.

 

 

Q3: What is the thermal conductivity of F4BTM298?

The thermal conductivity is 0.42 W/(m·K) in the Z-direction. This is higher than standard PTFE materials. It is due to the nano-ceramic fillers. Heat dissipation is improved.

 

 

Q4: What is the minimum thickness available for F4BTM298?

The minimum dielectric thickness is 0.254 mm (10 mils). Other thicknesses are available up to 12.0 mm. Please contact us for custom thickness requirements.

 

 

Ready to Get Started?

F4BTM298 or F4BTME298 raw laminate can be provided. Metal-backed variants (aluminum or copper) are also available. Fully fabricated 2-layer RF PCBs with immersion gold finish can be manufactured.

Contact us today for:

 

Material sampling and testing

 

RF circuit design assistance

 

Impedance calculation and design support

 

PCB quoting and DFM review

 

Technical support for your specific application