CLTE-XT™ High-Frequency Copper Clad Laminate: Optimized for Advanced RF Performance

CLTE-XT™ represents an evolution in high-frequency circuit materials, engineered to deliver enhanced electrical performance while maintaining robust mechanical and thermal reliability. As an advanced variant within the proven CLTE series, this PTFE-based laminate is specifically designed for demanding RF and microwave applications that require ultra-low signal loss, improved thermal stability of electrical properties, and consistent performance across frequency ranges. CLTE-XT is particularly well-suited for next-generation aerospace, defense, and telecommunications systems where signal integrity and power efficiency are paramount.

A defining characteristic of CLTE-XT is its significantly reduced Dissipation Factor (0.0010 @ 10 GHz), which represents less than half the signal loss of standard CLTE material. This makes it ideal for high-frequency, high-power applications where minimizing insertion loss is critical. Furthermore, CLTE-XT exhibits a negative Thermal Coefficient of Dielectric Constant (-8 ppm/°C), providing exceptional stability of electrical performance over temperature variations—a crucial advantage in environments with wide operational temperature ranges.

While offering superior electrical properties, CLTE-XT maintains excellent reliability with a UL 94 V-0 flammability rating, very low moisture absorption (0.02%), and outstanding thermal resistance, including a Time to Delamination exceeding 60 minutes at 288°C. Its balanced thermal expansion characteristics and strong copper adhesion ensure dimensional stability and reliable performance in multilayer constructions and challenging thermal environments.

Standard Properties Table

Standard Specifications of CLTE-XT Laminate:

Electrical Properties (@ 10 GHz, 23°C):

• Design Dielectric Constant (Dk): 2.93
• Process Dk by Thickness (see table below): 2.79-2.94
• Dissipation Factor (Df): 0.0010
• Thermal Coefficient of Dk: -8 ppm/°C
• Volume Resistivity: 4.25 × 10⁸ MΩ·cm
• Surface Resistivity: 2.49 × 10⁸ MΩ
• Dielectric Strength: 1000 V/mil

Thermal Properties:

Coefficient of Thermal Expansion (CTE):

• X-axis: 12.7 ppm/°C
• Y-axis: 13.7 ppm/°C
• Z-axis: 40.8 ppm/°C
• Decomposition Temperature (Td): 539°C
• Thermal Conductivity: 0.56 W/(m·K) (improved over CLTE)
• Time to Delamination (@ 288°C): >60 minutes

Mechanical & Physical Properties:

• Copper Peel Strength (after 10s @ 288°C): 1.7 N/mm (9 lbs/in)
• Dimensional Stability: -0.37 mm/m (MD), -0.67 mm/m (CMD)
• Moisture Absorption: 0.02%
• Flammability Rating: UL 94 V-0
• Density: 2.17 g/cm³

Dielectric Constant by Thickness:

• 0.0051" (0.130 mm): Dk = 2.79 ±0.03
• 0.0094" (0.239 mm): Dk = 2.89 ±0.03
• 0.020" (0.508 mm): Dk = 2.92 ±0.03
• 0.030" (0.762 mm): Dk = 2.94 ±0.03

Standard Product Offerings:

Available Thicknesses & Tolerances:

• 0.0051" (0.130 mm) ±0.0005"
• 0.0094" (0.239 mm) ±0.0007"
• 0.020" (0.508 mm) ±0.0010"
• 0.030" (0.762 mm) ±0.0010"

Standard Panel Sizes: 18" × 12" (457 × 305 mm) and 18" × 24" (457 × 610 mm)

Standard Copper Claddings: Same as CLTE, including Electrodeposited and Reverse Treated Copper Foils in ½ oz (18 µm) and 1 oz (35 µm) weights

CLTE-XT laminate delivers an optimal balance of ultra-low loss, temperature-stable electrical properties, and proven reliability. Its thickness-tuned dielectric constant and enhanced thermal characteristics make it an intelligent choice for designers seeking to maximize performance in advanced RF circuits, antenna systems, and high-frequency communications infrastructure where every decibel of loss matters.