Rogers Corporation specialized printed circuit boards (PCBs) serve demanding high frequency, high power, and high reliability applications spanning radars, satellites, wireless infrastructure, defense systems, and precision measurement instrumentation. As sensitivity, bandwidths, and data rates advance across electronics industry roadmaps, Rogers materials innovations in radio frequency (RF), microwave, and millimeter wave regimes enable ongoing breakthroughs through optimal combinations of electrical, mechanical, and thermal properties specifically tailored towards circuit fabrication.
This article explores key differentiating characteristics, material formulations, processing considerations, performance capabilities, application spaces, and technology evolution timelines across Rogers’ industry leading range of high performance PCB substrates for engineering applications requiring strictly controlled electrical responses previously unattainable from traditional rigid laminates.
Key Differentiators of Rogers PCBs
While composite glass weaves embedded in epoxy resin (FR-4) sufficiently serves many electronics applications up to a few gigahertz, several niche domains impose stringent demands more optimally addressed through specialty substrates to reliably achieve designed functionalities. Rogers Corporation focuses upon researching, developing, and manufacturing such high performance laminate materials purpose-built for precision RF/microwave/mmWave PCB fabrication. Differentiating capabilities span:
Tighter Dielectric Constant Tolerances – ControllingERR fluctuates between +/-5% introduces unacceptable variations in impedance matched transmission line characteristics degrading high frequency signal integrity. Rogers’ materials specify ERR values +/-2% even for ranges above 10 facilitating precision microwave circuits.
Controlled Thermal Expansion – Widely varying CTE between copper traces and surrounding dielectric substrate leads to substantial thermomechanical stresses over temperature inducing microcracks degrading reliability. Rogers materials maintain much closer thermal expansion matching across anticipated operating ranges minimizing these risks.
Reduced Water Absorption – Conventional glass weaves uptake atmospheric moisture altering electrical parameters and inducing reliability risks. Most Rogers’ laminates leverage hydrophobic polymers retaining <0.5% moisture even after immersive soaks.
Higher Glass Transition Temperatures – Approaching decomposition limits of epoxy resins around 170°C restricts lead-free soldering options. Materials like Rogers RO4000 series maintain glass transition temperatures above 280°C providing sufficient headroom for processing and use above 260°C lead-free solders without softening or degrading.
Superior High Frequency Skin Effect Losses – Dielectric losses dominate PCB conductor attenuation at microwave frequencies due to several 184 polymer relaxation modes. Rogers’ low loss laminates defer such modes beyond application bandwidths targeting stable, lower loss tangent peaks under 0.0025 enabling high frequency functionality at acceptable attenuation power costs.
Controlled Z-Axis CTE – Stackup constructions depend upon strong interlaminar bonding through curing receiving prepregs between layers. Excessive Z-axis expansion mismatch risks bond joint integrity threatening delamination. Rogers materials balance in-plane CTE with through-plane expansion matching rates.
Rogers PCB Substrate Families
Rogers offers over a dozen specialized PCB materials each optimized to address capabilities gaps urgently felt by electronics engineers pushing against the boundaries of possibility:
| Material Series | Description | Key Characteristics |
|---|---|---|
| RO3003TM | Commercial telecom frequency laminates | Tg: 280C ERR: 3.0 @ 10 GHz |
| RO3010TM/RO3035TM | Leaded microwave materials | Tg: >280C Loss Tangent: 0.0023-0.0027 |
| RO3210TM | High frequency, thermoset laminate | 89% PTFE blend High thermal conductivity |
| RO4000® | High frequency circuit materials | Low cost, high reliability |
| RO4003CTM | High frequency circuit material | Low loss for millimeter wave applications |
| RT/duroid® 6000 | High frequency laminates | PTFE composite Low loss |
| RT/duroid 5880LZ | Ultra low loss, high frequency laminate | Glass microfiber filled |
| RT/duroid 6006/6010LM | Ultra low loss, high frequency laminate | PTFE composite Low Dk tolerances |
| RT/duroid 6202PR | Ultra low loss, high frequency laminate | Low Df at 10+ GHz |
| TC350TM | High thermal conductivity material | For power circuits 70C/W/mK |
| TMM® | Microwave/RF materials | Temperature stable Low loss polymers |
| DUROID Microwave Materials | High frequency microwave laminates | Low loss, tight tolerance |
This diverse set of materials constitutes an unparalleled design toolbox granting engineers finely resolved selection granularity between cost, performance, and mechanical requirements when prototyping PCB technologies for wideband applications.
Rogers PCB Fabrication Notes
While Rogers materials enable breakthrough RF performance once manufactured into circuit boards, some unique considerations apply during fabrication which PCB shops must adapt processes to appropriately handle for success:
Tighter Impedance Tolerances – Lower, consistent dielectric constants facilitate precision transmission line impedance manufacture down to +/-5Ω on critical lines. Tighter etch tolerances paired with microvia stackups serve controlled characteristics up to 50 GHz.
Specialized Drilling – Dense glass microfibers dull drill bits faster than FR-4 while some composites abrasively erode tools. Frequent bit changing paired with optimized feed rates preserve hole positional accuracy and tolerances.
Modified Desmear – Plasma etch-back techniques better restore continuity through small drilled holes without as severe sidewall erosion versus traditional permanganate methods. Achieving desired interconnect densities and RF performance necessitates removing dielectric smear.
Special Laminate Flow – High filler loads make some Rogers materials more viscosity sensitive when melting prepregs together under heat and pressure. Standard lamination profiles may result in insufficient filling around traces compared to traditional epoxy blends.
Low Shrinkage – Consistent in-plane dimensional stability during curing benefits finer line tolerances and registration accuracy plus reliability by minimizing stresses over thermal transients. Warpage control maintains panel flatness.
Controlled Copper Roughness – Smooth copper foil interfaces facilitate fabricating ultra-thin dielectrics under 5 mils to push higher frequencies without fracturing. Modified surface treatments balance reduced profiles against drill smear and etching undercuts.
Close partnership between designers and manufacturers facilitates adapting conventional PCB workflows to fully leverage Rogers material performance advantages without compromising yields.
Rogers PCB Performance Characteristics
Rogers materials push electrical, mechanical, and thermal boundaries enabling RF designs with previously unattainable combinations of low loss, precision matching, noise isolation, size/weight reduction, power handling, and environmental resilience across metrics:
Dielectric Loss Tangent – Materials like RT/duroid® 6006 achieve loss tangents below 0.0025 at 10 GHz translating to lower signal attenuation for increased reachable range. TMM laminates approach 0.0020 through 10 GHz for minimal decay.
Dielectric Constant Tolerance – Consistency directly impacts impedance tolerances. RT/duroid 5870 and 5880 formulas reliably reach +/-1% capabilities.
Peel Strength – Withstanding challenging environments requires interlaminar bonding strength above 9 pli to prevent hot spots from delamination points degrading reliability. Rogers exceeds general 1-2 pli minimums with typical values in the 15 pli range on copper clad laminates.
Thermal Conductivity – Fluxing high DC and RF currents generates substantial heat fluxes needing mitigation. Specialized materials like TC350 transfer over 70 W/mK transversely through dielectric thicknesses whereas FR-4 rates below 0.3 W/mK.
Coefficient of Thermal Expansion – By matching copper foil CTE near 17 ppm/°C through filler loading and base resin formulations, Rogers achieves x and y thermal expansion matching reducing thermomechanical stresses over temperature cycling prone to inducing microcracks degrading electrical integrity over long term use.
Rogers combines such superlative substrate properties with extensive customer partnership feedback loops continually advancing next generation materials against industry roadmaps advancing microwave systems development year after year since the 1950s.
Rogers PCB Application Areas
Myriad cutting edge use cases across markets leverage Rogers materials for vital PCB components enabling system capabilities through optimized electrical responses:
Wireless Infrastructure – Low latency 5G NR base stations operate over 24+ GHz requiring low loss materials to maintain reachable range powering gigabit data rates through phased array beamforming architectures.
Radar & Electronic Warfare – Pulse-Doppler radar and EW jamming systems handle kilowatts of peak RF power needing thermal resilience paired with impedance consistency tolerating widely fluctuating transmission line signal strengths and ambient temperatures over long duty cycles.
Satellite Communications – Flight hardware PCBs must withstand extreme cold, radiation, and vibration environments over decades of zero maintenance orbital conditions while maintaining matched paths across high frequency microwave arrays facilitating ground link connections.
Electric Mobility – Rogers materials meet long term reliability requirements as high density motor controllers, battery management systems, autonomous sensor clusters, and chargers undergo substantial DC plus high frequency PWM currents imposing thermomechanical stresses which FR-4 falls short on.
Test & Measurement – Precision lab grade circuit boards in oscilloscopes, signal analy
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