Rogers vs Isola | Which Brand for Your RF Design

Rogers vs Isola: The Short Answer

Rogers dominates pure RF and millimeter-wave designs with ultra-low-loss PTFE and ceramic-filled laminates (Dk 2.2–10.2, Df as low as 0.0009). Isola targets the overlap zone between high-speed digital and moderate-RF applications with thermoset resin systems (Dk 3.0–3.6, Df down to 0.0017) that process on standard FR-4 press cycles. Choose Rogers when loss per unit length at frequencies above 10 GHz is the primary constraint; choose Isola when you need standard-FR-4-compatible fabrication, lower material cost, and your operating frequency stays below roughly 20 GHz.

Company and Technology Background

Rogers Corporation

Rogers has manufactured high-frequency laminates since the 1960s. Its portfolio spans PTFE/woven-glass (RT/duroid 5880, 5870), ceramic-filled PTFE (RO3003, RO3006), and thermoset ceramic-filled hydrocarbon (RO4000 series). The company’s strength is tightly controlled dielectric constant tolerance—typically ±0.02 to ±0.04 on Dk—critical for impedance-sensitive microstrip and stripline structures. Rogers materials are the de facto standard for radar, satellite communications, and 77 GHz automotive radar front-ends.

Isola Group

Isola is better known for mid-to-high-Tg FR-4 and high-speed-digital laminates (IS680, I-Tera MT40, Astra MT77). Its RF-capable grades use low-loss thermoset resin reinforced with spread glass or very-low-profile (VLP) glass styles. Because the resin chemistry is compatible with standard epoxy press cycles (typical cure 185 °C / 365 °F), Isola laminates can be laminated in the same facility that runs FR-4—a major cost and lead-time advantage. Isola’s Astra MT77 product line specifically targets 5G sub-6 GHz and automotive radar applications where moderate loss is acceptable.

Key Material Properties Compared

When working with these thicknesses, switching between mil (1 mil = 0.0254 mm) and mm is a constant task. The converter below handles that along with copper-weight-to-micron conversions.

For example, a 10 mil (0.254 mm) RO4350B core is a common choice for 50 Ω microstrip at 5.8 GHz; at the same thickness, Astra MT77’s lower Dk of 3.00 yields a slightly wider trace, which can ease fabrication tolerances.

Dielectric Loss: Where the Gap Matters

Below 6 GHz, the difference between Df 0.0037 (RO4350B) and 0.0031 (I-Tera MT40) is often negligible—on a 50 mm microstrip at 3.5 GHz, the additional insertion loss is under 0.02 dB. At 28 GHz, however, loss scales almost linearly with frequency, and the gap between Rogers’ PTFE grades (Df ≈ 0.001) and Isola’s best thermoset (Df ≈ 0.0017) becomes meaningful: roughly 0.15–0.20 dB/inch extra on a 50 Ω microstrip, depending on copper roughness.

Copper surface roughness interacts with loss more aggressively at millimeter-wave frequencies. Rogers offers laminates bonded with rolled or VLP copper (Ra ≈ 0.3–0.5 µm), while Isola’s Astra MT77 uses VLP ED copper (Rz ≈ 2.0 µm typical). At 77 GHz, conductor loss dominates, so Rogers’ smoother copper options give an additional edge beyond the Df advantage.

When Isola’s Loss Is Good Enough

For sub-6 GHz 5G base-station feeds, Wi-Fi 6E/7 front-end modules, and L-/S-band radar IF boards, Astra MT77 or I-Tera MT40 meet link-budget requirements comfortably. Many designs in the 1–10 GHz range use Isola laminates and still pass system-level EVM and noise-figure specs.

Thermal and Mechanical Reliability

Rogers RO4350B has a Tg above 280 °C and a z-axis CTE of 32 ppm/°C, making it robust through lead-free reflow (peak 260 °C). RO3003, being PTFE-based, has no true Tg but softens gradually, which requires careful lamination pressure control in multilayer builds.

Isola’s thermoset resins have a Tg around 200 °C—adequate for lead-free assembly but with a higher z-axis CTE (40–45 ppm/°C). In boards thicker than 2.0 mm with many plated vias, this CTE difference can affect barrel reliability. IPC-6012 Class 3 designs may need via-in-pad with conductive fill or micro-vias to mitigate stress, a consideration less pressing with RO4350B’s lower CTE. The IPC-6012 standard details acceptance criteria for plated-through-hole reliability under thermal excursion.

Fabrication and Processability

This is where Isola has a structural advantage. Every Isola RF-grade laminate uses a thermoset resin that cures on a standard 185 °C epoxy press cycle. That means:

• No special PTFE bonding films (Rogers’ PTFE grades need RO4450F or Taconic FastRise bondply).
• Standard drill parameters—no need for the lower feed rates and sharper bits that PTFE demands.
• Conventional desmear (permanganate) instead of plasma or sodium etch required for PTFE hole-wall preparation.
• Any fabricator tooled for high-Tg FR-4 multilayers can run Isola RF grades without process qualification.

Rogers’ RO4000 series shares some of this ease—RO4350B is the most fabrication-friendly Rogers material and can be drilled and plated with near-FR-4 processes. But RO3000 and RT/duroid grades require PTFE-experienced fabricators, longer drill cycles, and sodium-naphthalenide or plasma treatment for via adhesion.

Selecting the Right Isola Grade

Isola’s portfolio is broad, spanning everything from standard FR-4 (IS410) to ultra-low-loss RF grades. The selector tool below lets you filter by Dk range, Df, Tg, and application to narrow down which Isola laminate fits your design.

If the tool returns Astra MT77, you are likely in the 5G or automotive-radar feed-network space. If it returns I-Tera MT40, your design probably mixes high-speed serial links (PCIe Gen 5/6, 112G PAM4) with moderate RF paths—a common architecture in phased-array digital beamforming boards. For pure digital high-speed with no RF, I-Speed or IS680 AG may suffice, but those fall outside the Rogers-vs-Isola RF comparison.

Cost and Availability

Exact pricing depends on panel size, order volume, and regional distribution, so specific dollar figures are unreliable to quote. The relative picture, however, is consistent across the industry:

For volume production, the fabrication-cost premium of PTFE-based Rogers can exceed the raw material delta. A hybrid stackup—Rogers RF layers bonded to FR-4 or Isola digital layers—often delivers the best cost-performance trade-off for mixed-signal boards.

Frequency-Band Decision Guide

The table below maps common application bands to the most practical material choice, assuming mainstream volume production (not lab prototyping).

For designs straddling the 6–10 GHz boundary, run an insertion-loss budget. If total trace loss from connector to antenna is within 1 dB of your margin, Rogers is the safer bet. If you have 3+ dB of margin, Isola saves cost and lead time without compromising the system.

Stackup Considerations

Mixed-material stackups are increasingly common. A typical eight-layer 5G beamforming board might use Astra MT77 for the top two RF layers and I-Tera MT40 for the remaining high-speed digital layers, all bonded in one press cycle because both are thermoset. Achieving the same with Rogers requires RO4350B on the RF layers bonded to FR-4 cores using RO4450F prepreg—feasible, but it adds a bonding step and restricts the fabricator pool.

When the RF front-end operates above 24 GHz, a full-Rogers stackup (RO3003 + RO4450F bondply) is typical. The transmission-line geometry shifts toward grounded coplanar waveguide (GCPW), which demands tight Dk control across the laminate—a strength of Rogers’ ceramic-filled PTFE.

Rogers vs Isola: The Verdict

Choose Rogers when:

• Operating frequency is above 10 GHz and loss budget is tight.
• Dk tolerance of ±0.04 or better is required for impedance-critical lines.
• The application is 77 GHz automotive radar, Ku/Ka-band satcom, or military radar.
• Thermal conductivity matters (power amplifier substrates, high-power RF).

Choose Isola when:

• Operating frequency is below 10 GHz and loss margin is comfortable.
• The board mixes RF and high-speed digital, and you want one laminate family for the whole stackup.
• Standard-FR-4 fabrication flow is needed to keep cost and lead time low.
• Volume production demands multiple qualified fabricators without PTFE capability.

For a broader view of how these two brands stack up against other high-frequency laminate families, the RF laminate comparison hub covers Taconic, Panasonic Megtron, and several Chinese alternatives side by side. And for detailed RO4000-series datasheets, Rogers publishes complete Dk/Df-vs-frequency curves that are invaluable during simulation.

FAQ

Can Isola Astra MT77 replace Rogers RO4350B?

At frequencies below about 10 GHz, yes—Astra MT77 offers comparable Dk (3.00 vs 3.48) with lower Df (0.0017 vs 0.0037) and easier processing. Above 10 GHz, Rogers’ tighter Dk tolerance and lower moisture absorption give it an edge in phase-sensitive designs.

Is Isola cheaper than Rogers for RF PCBs?

Generally yes. Isola RF-grade laminates cost roughly 30–50 % less than equivalent Rogers grades at the raw-material level, and the fabrication premium is lower because Isola materials run on standard FR-4 press and drill processes.

Which material is better for 77 GHz automotive radar?

Rogers RO3003 or RT/duroid 5880. No Isola thermoset laminate is currently characterized or widely used at 77 GHz. The dielectric and conductor losses at millimeter-wave frequencies require PTFE-class Df values (≤ 0.001) and very smooth copper.

Can I mix Rogers and Isola in the same stackup?

It is possible but uncommon. The bonding chemistries differ—Rogers thermoset (RO4000) bonds well with FR-4 prepregs, while Isola thermoset bonds with its own prepreg system. Mixing the two resin families in one lamination cycle requires careful CTE matching and fabricator qualification. A hybrid Rogers-plus-FR-4 or all-Isola stackup is more practical.

Does Isola offer PTFE-based laminates?

No. Isola’s portfolio is entirely thermoset resin-based. If your design requires PTFE dielectric performance (Df < 0.001 at 10 GHz), Rogers, Taconic, or AGC (Nelco) are the primary options.