Rogers PCBs: Properties, Materials, Advantages and Applications

What are Rogers PCBs?

Rogers PCB is a printed circuit board produced by laminates from Rogers Corporation which is a leader in the production of RF and microwave PCB materials.

Materials of Rogers printed circuit boards are capable of performing in harsh rigorous environments in various applications, especially for high-frequency devices. Rogers PCB board is better in both electrical and mechanical properties than standard FR4 which will contribute to the durability, reliability, manufacturing methods, and cost of the product. The decomposition temperature of Rogers PCB board is up to 350 degrees Celsius. The loss tangent ranges from 0.0014 to 0.003 when operating over 10 GHz. Rogers printed circuit board is more expensive than standard FR4 PCB which is the basic level of PCB manufacturing.

Main Properties of Rogers PCBs

FR4 and Rogers PCB boards can be differentiated based on their parameters and the type of application where the working principle is required. Not every PCB requires expensive high-performing Rogers printed circuit boards, PCB can be designed with FR4. The functional classification can be categorized by frequency of operation, moisture absorption, impedance stability, and thermal management.

• Frequency of Operation: Standard FR4 PCBs can perform under ideal conditions till a certain range of frequency and Rogers material is the opted material for a higher range of frequencies. Certain high-frequency applications demand operational frequency over 500 MHz whereas FR4 is opted for applications with operational frequency lesser than or equal to 10MHz.
• Moisture Absorption: Standard Printer circuit board materials tend to absorb 0.1 or 0.2 percent of moisture from the ambient. As the moisture-absorbing nature of the material directly impacts the electrical and thermal performance of the PCB the environment of the application plays a huge factor in choosing between FR4 or Rogers material. The moisture absorbing percentage of the Rogers printed circuit board generally ranges from 0.02 to 0.08 percent and hence they are adaptable for rigorous environments like defense and aerospace applications.
• Impedance Stability: The Dk- Dielectric constant of FR4 material is approximately 4.5 whereas the Dk value of Rogers material range varies from 2.5 to 11 which says the stability of impedance. Rogers PCB board has low dielectric loss as the materials perform with a better frequency range.
• Thermal Management: When the operation temperatures exceed over 170 degrees Celsius the PCB materials tend to reach the glass transition temperature. The temperature limit is called the glass transition temperature, the higher the glass transition temperature the higher the performance.

Copper has a CTE of 18 ppm which means if the temperature rise is one degree, then it allows the material to expand by 18 parts per million. Standard FR4 material has a thermal conductivity of 0.1-0.5W/mK whereas Rogers printed circuit board material can be 1.0 W/mK and more. This concludes the thermally stable case for Rogers material as it can conduct heat and dissipate it much faster than FR4. This property also helps in better thermal management during the component assembly process. The glass transition temperature of Rogers material is close to 280 degrees Celsius.

Commonly Used Rogers PCB Materials

Rogers company produces many types of advanced RF and microwave materials, such as RO4000 series, RO3000 series, DiClad series, CuClad series, IM series, IsoClad series, TTM series, RT/droid series., etc. Here we just discuss a few most commonly used types.

• Rogers 4350B: Laminate of this material allows tight control dielectric constant and low dielectric loss. These materials are used for g=high power laminates and t is rated for UL 94 V-0. Dk is 3.66 and the best performing frequency range is 8 to 40 GHz so it is used for Cellular station antennas and microwave links.
• Rogers 4003C: Rogers 4003C provides equal di\electric constant on the entire PCB as the glass fabric/epoxy glass or conventional microwave laminated are the base materials, yet these materials require special treatment through hole and handling processes. RF tags are used with these PCBs and automotive-grade radars and sensors are used as the material Dk is approximately 3.55.
• Rogers 4534: Rogers 4534 provides both performance and cost which antenna design applications are used in products. The composition consists of reinforced glass ceramic fill providing lesser loss and controlled dielectric constant. Assembly process with higher reflow temperature process and compatible with almost all HASL-free solder paste.
• Rogers 3003: The dielectric constant is extremely stable and has a low dissipation factor which is good for RF PCBs. High-frequency Radar applications that operate close to 77 GHz, 6G wireless applications, and driver assistance products can be designed with this material.
• Rogers RT: These materials can be used for multilayer microwave applications as they provide low dielectric constant and lesser loss. These are used for missile guide systems, and military radar systems which require a low dielectric constant of 2.20 (Dk). Rogers RT has two types one is Duroid 6002 and the other is Duriod 5880. Both of them provide low dielectric constant and low dielectric loss enabling excellent precision on the Printed circuit board performance.

Key Advantages of Rogers PCBs

1. Controlled and Low Dielectric Constants: It is suitable for electronic devices that need high operating frequencies which cannot be achieved with FR4 material.
2. Low Signal Loss: Signal losses in the Printer circuits are low when compared to FR4 PCBs. Dielectric loss is less when compared to other materials which provides high performance and impedance control for highly efficient applications.
3. Low Outgassing: Outgassing is low in harsh environments and is easier when used in space applications.
4. Excellent Thermal Management: Rogers is a reliable material for thermal management with low CTE and is used for RF and microwave applications. The thermal withstanding temperature is close to 280 degrees and the moisture absorption range is low. It can also act as a heat sink for high-power applications.
5. Suitable for Impedance Control PCB: A controlled impedance technique can be achieved easily.
6. High Reliability: Through-hole components are easily adaptable due to reliable Rogers printed circuit board material. The physical stability of the PVB is also more.

Applications of Rogers PCBs

• Aerospace & Aviation: Radio frequency operation in aerospace applications is more and to perform with better efficiency Rogers PCB boards are used. Rogers ceramic PCBs can operate in harsh environments without degrading performance, are reliable, and ensure safety measures in air travel.
• Military Applications: High functional PCBs in which the circuit operates in high power and high-performance needs are required in Military applications like missiles, defense monitoring systems, and drones which operate with zero margin error.
• Telecom Applications: Satellite and telecommunication applications require seamless operation in Earth’s orbit which needs to keep communication effective. Internet communications are also widely dependent on these Rogers PCB boards. Mobile phones, tabs, and other communication devices adapt to Rogers PCB board.
• Consumer Electronic Applications: Regular consumer electronics have high-frequency applications that do not operate in high tensile environments yet need to be high performance like smartphones, and radio stations where high-performance Rogers printed circuit board is used.