Rogers TMM thermoset microwave materials are hydrocarbon ceramics and thermoset polymers composites specifically designed for strip-line and microstrip applications. TMM comes in various claddings and dielectric constants. TMM laminates feature some mechanical and electrical properties that make them ideal for several applications.

TMM has an excellent thermal expansion coefficient, low dielectric constant (Dk) thermal change rate, and consistent dielectric constant. TMM can offer greater specifications of copper coating. These laminates feature the properties of both PTFE microwave circuit laminates and ceramic without needing the production techniques used for these materials.

Like other laminates that need sodium napthanate treatment before undergoing electroless plating, TMM is unique as it doesn’t require such treatment.  One of the most amazing properties of TMM laminates is their extremely low thermal coefficient of Dk, which is usually lower than 30 ppm/°C.

These laminates don’t soften when they pass through heat. Due to this, wire bonding of leads to circuit traces can be easily performed without experiencing substrate deformation or pad lifting. The isotropic coefficients of thermal expansion in Rogers TMM are matched to copper, allowing for high-reliability PTH and low levels of etching shrinkage.

TMM’s thermal conductivity is almost twice of ceramic or traditional PTFE laminates, enabling it to boost heat removal. These laminates are bonded to aluminum plates or brass directly or covered with electrodeposited copper foil.  The substrate thickness is between 0.015” and 0.500.” The base substrate is solvents and etchants-resistant.

According to Rogers datasheet, TMM offers Dk from 3 to 14 while having a tolerance of +/ 0.0015 inches. Rogers TMM laminates come in TMM 3, TMM 4, TMM 6, and TMM 10.

Features of Rogers TMM

Rogers TMM 3 PCB

Wide range of Dks: The dielectric constants of Rogers TMM are between 3 and 13. The dielectric constants of these laminates depend on various factors like moisture content, temperature, etc. For instance TMM4 has a dielectric constant of 4.50 +/- .045 while TMM 6 has Dk of 6.0 +/- .080.

Low thermal coefficient of dielectric constant: This is one amazing property of Rogers TMM. It has a very low thermal coefficient of Dk.

Excellent thermal conductivity: Rogers TMM thermoset microwave materials have an excellent thermal conductivity which is between 0.70 and 0.76. The thermal conductivity of these materials is twice that of ceramic or traditional PTFE laminates. These laminates are a good option for engineers as they help to reduce energy consumption and facilitate heat removal.

Coefficient of thermal expansion: The Coefficient of thermal expansion (CTE) measures the rate of expansion of a material when it is heated. Rogers TMM laminates feature low CTE matched to copper, hence enabling high reliability of PTH.

Low Dissipation factor: Rogers TMM laminates’ dissipation factors are between 0.0019 and 0.0023 at 10 GHz. A low dissipation factor indicates that this material has a more efficient insulation system. TMM’s dissipation factor is low even at room temperature.

Advantages of Rogers TMM

Rogers TMM laminates are high-grade microwave materials with great electrical and mechanical properties. These materials combine the benefits of both PTFE microwave circuits and ceramic laminates.

Exceptional mechanical properties: Rogers TMM laminates resist cold and creep flow which makes them mechanically reliable and stable.

Resistant to chemical reagent: Rogers TMM laminates resist chemical reagents which help to ensure that there is no damage during the placement and production process. These microwave materials maintain their original properties after they have been exposed to chemical reagents for a specific time.

Thermosetting resin: Rogers TMM laminates are thermosetting resin that ensures good wire bonding. These materials can withstand any type of temperature, even high heat.

Moisture absorption: These laminates can survive in a humid environment. Rogers TMM can absorb moisture from its environment; hence, it is a good material for an environment with high levels of humidity.

Major Applications of Rogers TMM

Rogers TMM laminates are useful in various applications. Due to the features and benefits of these microwave materials, they are considered a suitable option in RF and microwave circuits design, production of patch antennas, power amplifiers, and chip testers.

RF and microwave circuit: Radio Frequency (RF) and microwave circuit designers are faced with a lot of challenges and Rogers TMM laminates are specifically designed to provide a solution to some of these challenges.

These laminates are commonly used in microwave circuits due to their thermal conductivity and a wide range of dielectric constants. Radio frequency and microwave engineers use Rogers TMM thermoset microwave materials to design devices that receive or transmit radio waves.

Satellite communication system: Satellite communication systems utilize radio waves to transfer signals to the antennas on the Earth. A satellite can get signals from the earth and make use of a transponder to retransmit the signals.

Since Rogers TMM is a thermoset polymer composite that features both electrical and mechanical properties it is a core component of the satellite communication system.

Patch antenna: Patch antennas are gaining popularity within the mobile phone industry since they are easy to fabricate and cost-effective. Patch antennas require high-grade microwave materials. Rogers TMM provides a wide range of Dk and thicknesses that allow designers to achieve bandwidth and space requirements.

Global positioning system antennas: Most receiver manufacturers make use of microstrip antennas. A GPS antenna receives and transfers radio signals sent by definite frequencies from GPS satellites. These frequencies are then converted into electronic signals so that GPS receivers can utilize them. Rogers TMM laminates are a vital component of these antennas.

Power amplifiers: Power amplifiers facilitate radio signals to power levels ideal for a wired transmission to the receiver. Rogers is known for offering materials for microwave power amplifiers. Rogers TMM’s dielectric constants and mechanical properties offer the maximum power output.

Conclusion

Rogers TMM is a laminate based on thermosetting polymers, hydrocarbons, and ceramics. These laminates have processing advantages when compared with some alumina filler substrates. Rogers TMM laminates are available in TMM 10, TMM6, TMM 4, etc. however, each of these laminates have their own unique but similar properties.  

These microwave materials have mechanical and electrical properties that make them useful in several applications. Rogers TMM laminates are not only suitable for microstrip applications, but are also high-reliability stripline applications.