PCB Fabrication

Difference between RogersPCB and FR4PCB - PCB Power Market USA

    FR4 is the most common material that PCB manufacturers use for making printed circuit boards. It is cheap, readily available, and performs satisfactorily for most applications. However, the above is true as long as the operating frequency is low. With the increase in signal frequencies, the losses in the board rise, and the signal integrity suffers. This is where PCB manufacturing uses better materials, like the Rogers PCB. Rogers company makes the raw material for such boards capable of handling high frequencies.

    FR4 is an acronym for Flame Retardant level 4. This is a glass fiber and epoxy composite, with a lamination of copper foil on one or both sides. In comparison, Rogers PCB is of different composition, using a ceramic base rather than glass fiber. There are many varieties of Rogers PCBs, some with woven glass reinforced hydrocarbon. That makes the board’s electrical performance more like that of PTFE.

    Other Rogers PCBs may have a composition of laminate materials like epoxy reinforced with woven glass, PTFE ceramic laminates, and cross-piled laminates reinforced with woven glass.

    Why use the Rogers PCB material?

    There are several reasons for prioritizing Rogers’ materials over others. The main reason is these materials from Rogers perform superbly in the most challenging environments. Although Rogers PCBs are more expensive than other materials, their better performance in adverse conditions makes their higher price worthwhile.

    The FR4 material provides an elementary standard for PCB board substrates. It provides an effective balance between cost, performance, durability, ease of production, and electrical properties. However, as performance and electrical properties start to play a more important role in the printed circuit board design, the FR4 material falls short. On the other hand, Rogers

    • Better impedance control
    • Low electrical signal losses
    • Low dielectric loss
    • Better thermal management
    • Low outgassing
    • Wider dielectric constant
    • Cost-effective PCB printing / fabrication

    How is FR4 Different from Rogers PCB?

    Frequency of Operation

    The major difference between ordinary PCBs made of FR4 and Rogers PCB lies in their application. FR4 PCBs are limited to a certain range of frequencies, while the performance of Rogers material extends to a much larger frequency range. OEMs use Rogers PCBs mostly in high-frequency applications extending above 500 MHz, while FR4 PCBs can barely reach 10 MHz.

    Moisture Absorption

    Most PCB board materials absorb moisture to the extent of between 0.1 and 0.2 percent. Moisture absorption has a direct effect on the electrical and thermal properties of the material. Higher moisture absorption reduces the performance and efficiency of the material.

    For Rogers PCB material, on the other hand, the value of moisture absorption ranges from 0.02 to 0.08 percent. This makes the Rogers PCB material more suitable for severe environments like in aerospace and defense applications.

    Impedance Stability

    The dielectric constant of FR4 is about 4.5. The corresponding value for Rogers PCB materials ranges from 2.5 to 11. Therefore, the impedance stability is much higher for Rogers PCB materials.

    Thermal Management

    Thermal conductivity for FR4 PCB materials is about 0.3 W/mK. The corresponding figure for Rogers PCB materials ranges from 0.5 to 0.95 W/mK. That means, Rogers materials conduct more heat as compared to FR4 materials, and it makes thermal management easier.

    Types of Rogers PCB Material

    Rogers makes various types of PCB material for different applications. These include:

    Rogers 4350B: This is a low loss material with stable control on its dielectric constant. Suitable material for high-power RF designs.

    Rogers 3003: This material is suitable for ADAS, 5G wireless applications and automotive radar applications operating at 77 GHz.

    Rogers RT/Duroid 6002: This material has a very low dielectric constant. Ideal for microwave applications. Good for multi-layered board designs.

    Rogers RT/Duroid 5880: This material has a low dielectric constant and low dielectric loss. Ideal for high frequency/broadband applications. Randomly oriented microfibers reinforcing the PTFE composites in the material help to maintain a uniform dielectric constant.

    Rogers 4534: This material is optimized for performance and cost. Suitable for RF applications like antennas. This material is glass-reinforced, ceramic-filled to offer low loss performance, controlled dielectric constant, and great passive intermodulation responses. Suitable for applications like mobile infrastructure and microstrip antennas. This material is compatible with lead free, high-temperature solder processing.

    Rogers 4003C: This laminate utilizes both 1080 and 1674 glass fabric styles. It provides a tight control on the dielectric constant and low loss. It utilizes the same processing methods as standard epoxy/glass, but at a fraction of the cost of conventional microwave laminates. No special through-hole treatments or handling procedures are necessary, as in the case of PTFE based microwave materials.

    Conclusion

    For applications such as mobile networking, space technology, microwave, and radio frequencies, Rogers PCB materials offer outstanding performance over any other types of PCB materials, including FR4. Although more expensive than other materials are, Rogers PCB materials are worth their while when printed circuit boards must work in adverse environmental conditions and at high frequencies with very high reliability.

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