Wangling TF960 Custom PCB High DK 9.6 Laminate 0.635mm Immersion Silver Finish

High-Frequency RF / Microwave Printed Circuit Board — Technical Product Description

Executive Summary

Thisarticle presents a comprehensive technical overview of the TF960 PCB, a 2-layer rigid high-frequency printed circuit board built on a 0.635 mm TF960 ceramic-filled PTFE core with an immersion silver surface finish. Engineered for RF and microwave applications requiring ultra-low signal loss and precise impedance control, this board combines a dielectric constant (DK) of 9.6 at 10 GHz with a dissipation factor (Df) of just 0.0012, making it suitable for 5G/6G antenna systems, automotive and aerospace radar, satellite communications, and high-power RF amplifiers. 

The following sections detail the PCB construction, layer stackup, manufacturing statistics, key performance features, and quality assurance. The description also concludes with an in-depth technical profile of the TF960 copper-clad laminate (CCL) material, providing engineers with a complete understanding of both the finished board and the substrate that underpins its performance.

Part 1: PCB Product Description

1.1 Product Overview

The Wangling TF960 PCB is a 2-layer rigid high-frequency circuit board measuring 102 mm × 86 mm per panel, with a finished board thickness of 0.7 mm. At its core lies a 0.635 mm (25 mil) TF960 laminate — a modified PTFE resin system reinforced with micron-sized ceramic fillers — clad with 35 μm (1 oz) copper on both outer layers. The board features an immersion silver surface finish, a blue solder mask on the top side, and white silkscreen for component identification.

1.2 PCB Construction Details

The table below summarizes the key manufacturing and construction parameters of the 2-layer TF960 PCB, covering dimensional tolerances, feature capabilities, surface finishes, and quality assurance measures.

1.3 PCB Stackup

The board employs a symmetric 2-layer stackup with a TF960 dielectric cores and wiched between two 35 μm copper layers, as detailed in the table below. This simple, balanced structure ensures consistent impedance and minimizes warpage during assembly.

1.4 PCB Statistics

The following table provides a quantitative breakdown of the board's component and interconnect density, including pad counts, via quantities, and net count. These figures reflect the actual design data supplied in Gerber RS-274-X format.

1.5 Key Features and Benefits

The TF960 Immersion Silver PCB delivers several differentiated performance characteristics that set it apart from conventional FR-4-based boards. First and foremost, the TF960 core offers a tightly controlled dielectric constant of 9.6 ± 0.19 at 10 GHz, enabling precise impedance matching in high-frequency circuits where even minor DK variations can degrade antenna gain and filter response. The ultra-low dissipation factor of 0.0012 at 10 GHz minimizes insertion loss, ensuring that signal power is efficiently transmitted through transmission lines rather than dissipated as heat in the dielectric.

Thermally, the material exhibits a coefficient of thermal expansion (CTE) of 50 ppm/℃ in both the X and Y axes and 65 ppm/℃ in the Z axis, providing excellent dimensional stability during reflow soldering and across operating temperature cycles. The Z-axis CTE of 65 ppm/℃ is notably lower than typical FR-4 values (70–90 ppm/℃), reducing the risk of plated-through-hole fatigue under thermal cycling. Furthermore, the board supports 260 ℃ lead-free assembly temperatures and carries a UL 94-V0 flammability rating, meeting modern regulatory and safety requirements.

Moisture absorption is rated at ≤ 0.05 %, significantly lower than standard FR-4 (typically 0.15–0.30 %), which ensures that dielectric properties remain stable in humid environments — a critical factor for outdoor RF equipment and aerospace applications. The high DK of 9.6 is particularly advantageous for miniaturizing antenna and filter designs, as higher dielectric constants allow for shorter guided-wavelength dimensions and more compact circuit layouts.

1.6 Surface Finish: Immersion Silver

The immersion silver (ImAg) surface finish provides a flat, highly solderable surface with excellent contact resistance and signal integrity at high frequencies. Unlike HASL (Hot Air Solder Leveling), immersion silver offers a truly coplanar surface ideal for fine-pitch SMT components and high-frequency RF connectors. It is lead-free and RoHS-compliant, maintaining good shelf life when properly stored under dry conditions. The silver layer also provides low contact resistance, making it suitable for RF switch contacts, high-speed digital interfaces, and applications where repeated mating cycles are required.

1.7 Typical Applications

The TF960 high frequency PCB is well-suited for a broad range of high-frequency applications, including:

• Microwave and RF transceivers for communication systems

• 5G / 6G massive MIMO antenna arrays and base station RF front-ends

• Automotive ADAS radar (77 GHz) and aerospace radar systems

• Satellite communication payloads and ground station equipment

• High-power RF amplifiers and power combiners / dividers

• Test and measurement equipment, including vector network analyzers

1.9 PCB Conclusion

The TF960 PCB represents a carefully engineered balance of high-frequency electrical performance, thermal reliability, and manufacturing practicality. Its 0.635 mm TF960 core with DK 9.6 and Df 0.0012 at 10 GHz, combined with a robust 2-layer construction, immersion silver finish, and IPC-Class-2 quality assurance, makes it a dependable choice for RF and microwave designers seeking low-loss, dimensionally stable circuit boards. 

The straightforward stackup and absence of blind vias also contribute to cost-effective fabrication without compromising high-frequency performance. The following section provides a detailed technical profile of the TF960 copper-clad laminate material itself, offering engineers deeper insight into the material properties that underpin this board's performance.

Part 2: CCL Material Knowledge — TF960 High-Frequency Laminate

2.1 Material Introduction

TF960 is a high-frequency copper-clad laminate (CCL) belonging to the TF series of PTFE-ceramic composite dielectric substrates. The material is composed of polytetrafluoroethylene (PTFE) resin — renowned for its exceptional microwave performance and thermal stability — composited with micron-sized ceramic fillers. Unlike traditional FR-4 or even glass-reinforced PTFE laminates, the TFlaminateseries contains no glass fabric, relying instead on the ceramic filler to provide mechanical rigidity and to precisely tune the dielectric constant. By adjusting the ratio of ceramic filler to PTFE resin, manufacturers can achieve dielectric constants ranging from 3.0 to 16.0 across the TF product family, with TF960 specifically formulated to a DK of 9.6.

The TF naming convention distinguishes three product forms: TF denotes the bare dielectric material without copper cladding; TF-1 refers to single-sided copper-clad laminate; and TF-2 denotes double-sided copper-clad laminate, which is the form used in the TF960 PCB described in Part 1. This nomenclature system allows customers to select the appropriate cladding configuration based on their specific circuit design requirements.

2.2 Product Features

TF960 offers a compelling set of material properties for high-frequency circuit designers:

• Dielectric constant of 9.6 at 10 GHz with a tight tolerance of ±0.19 (±2 %), ensuring consistent impedance control across production lots.

• Ultra-low dissipation factor of 0.0012 at 10 GHz, minimizing dielectric loss in microwave and millimeter-wave circuits.

• Long-term operating temperature range of -80 ℃ to +200 ℃, extending beyond the capabilities of conventional thermoplastic substrates.

• Available thickness range from 0.635 mm to 2.5 mm, accommodating a variety of impedance and mechanical requirements.

• Radiation resistance and low outgassing characteristics, making the material suitable for aerospace and space-borne applications.

• PCB processing compatibility with standard thermoplastic material fabrication workflows, including drilling, plating, and lamination.

2.3 Complete Technical Data Sheet

The table below presents the complete technical specifications for TF960, including electrical, mechanical, thermal, and environmental properties, along with their respective test conditions and units. All values are typical measured data intended to assist customers in material selection.

2.4 Density and Thermal Conductivity

In addition to the electrical and mechanical parameters above, TF960 exhibits the following physical properties relevant to thermal management and weight-sensitive designs. The density of 3.02 g/cm³ reflects the high ceramic filler loading required to achieve the DK of 9.6, while the thermal conductivity of 0.68 W/(m·K) provides moderate heat-spreading capability for high-power RF circuits.

2.5 Available Specifications

TF960 laminate is offered in standard panel sizes and thicknesses, with ED (electrodeposited) copper foil cladding. The standard available panel sizes are 150 mm × 150 mm and 250 mm × 250 mm. Copper foil thickness options include 0.018 mm (1/2 oz) and 0.035 mm (1 oz). The table below lists the standard available dielectric thicknesses and their respective tolerances. Customers should specify whether the quoted thickness refers to the total copper-inclusive thickness or the dielectric-only thickness when placing orders. Non-standard thicknesses are available upon request.

2.6 Material Composition and Processing

TF960 is composed of PTFE resin, ceramic fillers, and ED copper foil. The absence of glass fabric in the TF series distinguishes it from glass-reinforced PTFE laminates and contributes to its isotropic dielectric properties — the DK measured in the Z-axis (thickness direction) is consistent and well-characterized, without the local variations that can occur near glass fiber bundles. The material is processed using standard PCB fabrication techniques compatible with thermoplastic materials, including mechanical drilling, electroless copper deposition, pattern plating, and solder mask application.

The peel strength of > 0.6 N/mm (1 oz copper, normal condition) and > 0.4 N/mm (after humidity cycling) ensures reliable copper-to-dielectric adhesion under typical operating conditions. The DK temperature coefficient of -260 ppm/℃ over the range of -55 ℃ to 150 ℃ indicates a slight decrease in DK with increasing temperature, which designers should account for in wide-temperature-range impedance simulations. The volume resistivity of > 1 × 10⁹ MΩ·cm and surface resistance of > 1 × 10⁷ MΩ confirm excellent insulating properties for high-voltage RF applications.

2.7 Test Methods and Standards

All TF960 material properties are characterized using recognized industry test methods. The dielectric constant is measured in the Z-axis direction using the stripline method per GB/T 12636-1990 or IPC-TM-650 2.5.5.5. Other electrical, mechanical, and thermal properties are tested in accordance with or by reference to IPC-TM-650 or GB/T 4722-2017 standards. All published data represent typical measured values intended to assist customers in material selection; they do not constitute an express or implied warranty, and customers are responsible for verifying the suitability of TF960 for their specific application requirements.

2.8 TF960 Laminate Product Image

The image below shows the TF960 high-frequency copper-clad laminate material.

Figure 1: TF960 High-Frequency Copper-Clad Laminate

2.9 CCL Conclusion

TF960 is a specialized high-frequency copper-clad laminate that combines the inherently low-loss characteristics of PTFE with the tunable dielectric properties of ceramic fillers, delivering a DK of 9.6 with exceptional stability and an ultra-low Df of 0.0012 at 10 GHz. Its broad operating temperature range (-80 ℃ to 200 ℃), low moisture absorption (≤ 0.05 %), radiation resistance, and low outgassing make it suitable for demanding applications spanning 5G/6G communications, automotive radar, aerospace, and satellite systems. 

The glass-fabric-free construction ensures isotropic dielectric behavior and consistent Z-axis DK, while the standard thickness range of 0.635 mm to 2.5 mm and ED copper foil options of 1/2 oz and 1 oz provide designers with a flexible, well-characterized material platform. When fabricated into a 2-layer PCB with immersion silver finish — as detailed in Part 1 — TF960 delivers a reliable, high-performance solution for RF and microwave circuit designers who demand low insertion loss, precise impedance control, and long-term thermal and environmental stability.