Introduction
Rogers TMM® Thermoset Microwave Materials represent a unique class of high-performance laminates that combine the best attributes of both ceramic and PTFE-based microwave substrates. Designed for high plated-through-hole reliability, stripline, and microstrip circuit applications, TMM laminates deliver exceptional stability, precision, and manufacturability — making them ideal for demanding RF, microwave, and millimeter-wave designs.
Material Composition and Design
TMM® laminates are ceramic–hydrocarbon–thermoset polymer composites engineered to provide outstanding mechanical strength and electrical performance.
Unlike conventional PTFE-based materials, TMM laminates do not require sodium naphthanate surface treatment prior to electroless plating, which simplifies fabrication and reduces processing time.
Each grade of TMM laminate is available in a broad range of dielectric constants (Dk) and cladding options, allowing designers to choose the optimal balance between electrical performance and cost-efficiency.
Superior Electrical and Thermal Stability
A key feature of Rogers TMM® materials is their exceptionally low thermal coefficient of dielectric constant (typically < 30 ppm/°C).
This ensures minimal variation in signal propagation speed and impedance over wide temperature ranges — a critical factor in maintaining phase stability for RF and microwave circuits.
TMM laminates also exhibit isotropic coefficients of thermal expansion (CTE) closely matched to copper. This compatibility significantly improves plated-through-hole reliability and reduces etch shrinkage, ensuring dimensional stability even under thermal cycling.
Enhanced Heat Dissipation and Reliability
With thermal conductivity nearly twice that of traditional PTFE/ceramic laminates, TMM materials provide superior heat management. This feature supports power amplifier, radar, and base station applications where efficient heat removal is essential for long-term reliability.
Moreover, the thermoset resin system used in TMM laminates does not soften when heated, allowing wire bonding of component leads directly to circuit traces without the risk of pad lifting or substrate deformation.
Manufacturing Flexibility
TMM laminates combine the robustness of ceramic substrates with the process simplicity of soft PTFE materials, enabling compatibility with standard PCB manufacturing techniques.
They can be supplied with:
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1/2 oz to 2 oz electrodeposited copper foil
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Direct metal bonding to aluminum or brass plates for improved mechanical rigidity
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Substrate thicknesses from 0.015” to 0.500”, covering a wide range of design needs
These materials are fully resistant to standard etchants and solvents, allowing manufacturers like KKPCB to process TMM-based PCBs using all common printed wiring board (PWB) methods.
Applications
Rogers TMM® laminates are widely used in:
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RF/microwave power amplifiers
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Antenna feed networks
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Radar front-end modules
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High-frequency communication systems
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Aerospace and defense electronics
At KKPCB, we utilize TMM materials to manufacture high-reliability RF and microwave PCBs, supporting frequencies up to millimeter-wave bands (up to 77 GHz and beyond) with precise impedance control and low loss.
