Rogers RO4350B vs Megtron 6

30-Second Decision

Parameter	RO4350B	Megtron 6	Winner
Dk @10 GHz	3.48	3.71	RO4350B
Df @10 GHz	0.0037	0.0044	RO4350B
Tg	280C+	200C	RO4350B
CTE (z-axis)	32 ppm/C	45 ppm/C	RO4350B
Standard process compatible	Mostly	Fully	Megtron 6
Max practical layer count	8-10L	30L+	Megtron 6
Cost vs FR-4	3-5x	1.5-2x	Megtron 6
Lead time	3-4 weeks	2-3 weeks	Megtron 6

Bottom line: If your design is a dedicated RF front-end (antenna feed, LNA, filter) at 2-20 GHz with fewer than 10 layers, choose RO4350B. If you need a high-layer-count mixed-signal board with both high-speed digital (PCIe Gen5, 112G SerDes) and moderate RF performance, choose Megtron 6.

Electrical Performance: The Numbers That Matter

Dielectric Constant (Dk) Stability

RO4350B maintains Dk within +/-0.05 from 1 to 40 GHz. Megtron 6 shows more variation above 20 GHz, with Dk drift of +/-0.08. For impedance-controlled designs where tight tolerance matters (antenna matching networks, filter tuning), this stability directly affects yield.

Practical impact: A 50-ohm microstrip on RO4350B stays within +/-2 ohms across a 10 GHz bandwidth. The same trace on Megtron 6 may vary +/-4 ohms — acceptable for digital, problematic for RF.

Loss Tangent (Df) and Insertion Loss

At 10 GHz over a 100mm trace:

RO4350B: 0.28 dB insertion loss
Megtron 6: 0.34 dB insertion loss
Standard FR-4 (Dk ~4.4, Df ~0.02): 1.5 dB insertion loss

The 0.06 dB difference between RO4350B and Megtron 6 becomes significant in:

Phased array feeds with 16+ elements (cumulative loss budget)
Multi-stage filter designs where every 0.1 dB matters
Long backplane channels above 25 Gbps NRZ

For PCIe Gen5 (32 GT/s) over 200mm, both materials deliver adequate eye opening. The difference only surfaces at 112G PAM4 channel lengths above 150mm.

RO4350B vs Megtron 6 comparison chart

Fabrication and Processability

This is where Megtron 6 pulls ahead decisively.

Drilling

Parameter	RO4350B	Megtron 6
Mechanical drill min	0.2mm (standard)	0.15mm
Laser drill compatible	Yes (with tuning)	Yes (standard params)
Drill wear rate	Higher (ceramic filler)	Normal
Hole wall quality	Good (needs deburr)	Excellent

RO4350B contains ceramic filler that accelerates drill bit wear. Production runs above 500 panels require more frequent bit changes, adding 5-10% to drilling cost.

Lamination

RO4350B requires:

Specific bonding films (RO4450F or low-flow prepregs)
Tighter temperature ramps (2C/min vs 3-4C/min standard)
Not all fab shops have qualified RO4350B processes

Megtron 6 laminates with standard FR-4 prepregs and press cycles. Any shop running high-Tg FR-4 can process Megtron 6 without qualification.

RF PCB EXPERTISE

Not Sure Which Material Fits Your Design?

Our engineers work with both RO4350B and Megtron 6 daily. Upload your stackup for a material recommendation based on your actual frequency plan.

Get Material Recommendation ›

Hybrid Stackup: Using Both Materials Together

For complex systems (phased array radar, 5G base station), the optimal approach is often a hybrid stackup:

RF layers (antenna/feed): RO4350B cores for antenna elements and RF signal routing
Digital layers (FPGA, SerDes): Megtron 6 for high-speed digital interconnects
Power layers: Standard high-Tg FR-4 (cost optimization)

Hybrid stackup example (10-layer):

L1  — RO4350B — Antenna/RF signals
L2  — GND (reference)
L3  — Megtron 6 — High-speed digital
L4  — GND
L5  — FR-4 — Power
L6  — FR-4 — Power  
L7  — GND
L8  — Megtron 6 — High-speed digital
L9  — GND (reference)
L10 — RO4350B — RF signals

Challenges of hybrid:

CTE mismatch between materials creates stress during thermal cycling
Requires qualification of bonding film between dissimilar materials
Limited to shops experienced with mixed-dielectric builds
Add 20-30% to cost vs single-material stackup

AtlasPCB regularly fabricates hybrid Rogers/FR-4 stackups with controlled CTE transitions.

MIXED-DIELECTRIC BUILDS

Hybrid Stackup? We Build Them Weekly.

Rogers + Megtron + FR-4 in a single board. Our lamination team has qualified 40+ hybrid material combinations.

View RF Capabilities ›

Application Decision Matrix

Application	Recommended	Reason
77 GHz automotive radar	RO4350B (or RO3003)	Loss budget too tight for Megtron 6
5G sub-6 GHz massive MIMO	Megtron 6	20+ layers, standard processing, adequate loss
28 GHz mmWave small cell	RO4350B (RF) + Megtron 6 (digital)	Hybrid approach
400G switch/router backplane	Megtron 6 (or Megtron 7)	Layer count > 20, standard flow
Satellite L/S band transponder	RO4350B	Thermal reliability, low outgassing
PCIe Gen5 server board	Megtron 6	Cost-effective, 16-24 layers
Phased array antenna element	RO4350B	Dk stability for beam steering accuracy
Test & measurement (VNA cal board)	RO4350B	Tightest Dk tolerance available

PROTOTYPE FAST-TRACK

Rogers and Megtron In Stock

We stock RO4350B (20/30/60mil) and Megtron 6 cores. Prototype in 7-10 days for RF boards.

Upload Gerber Files ›

Cost Comparison: Real-World Pricing

For a typical 6-layer, 100x100mm, 10-piece prototype run:

Material	Panel Cost (approx.)	Lead Time
Standard FR-4 (Tg170)	$180-250	5-7 days
Megtron 6	$320-450	10-14 days
RO4350B (all layers)	$650-900	14-21 days
Hybrid RO4350B + FR-4	$450-650	12-18 days

Volume pricing at 1000 pcs (same board):

Standard FR-4: $8-12/board
Megtron 6: $14-22/board
RO4350B: $28-45/board

The 2-3x premium for Rogers only makes sense when electrical performance requirements genuinely demand it. Many designers over-specify material — using RO4350B where Megtron 6 suffices wastes 40-60% of material budget.

Standards and Specifications

Standard	Relevance
IPC-4103	Specification for Rogers-type materials (thermoset microwave)
IPC-4101/126	Megtron 6 equivalent high-speed digital laminate
IPC-6012ES	Space/military addendum (relevant for RO4350B applications)
MIL-PRF-31032	Qualified product list — check if your Rogers variant is listed

ATLASPCB

Ready to Compare Quotes?

Upload your design — we quote both RO4350B and Megtron 6 options so you can compare cost vs performance with real numbers.

Get Dual-Material Quote ›

Related Reading:

About AtlasPCB — We specialize in complex PCB manufacturing for HDI, RF, and high-reliability applications. Explore our RF and high-frequency PCB services, Rogers RO4350B PCB manufacturing, or get an Megtron 6 & 7 low-loss PCB manufacturing . Every order includes free engineering review. Get your quote.

Reviewed by AtlasPCB Engineering Team — IPC-certified manufacturing specialists with 15+ years of production experience in HDI, RF, and high-reliability PCB fabrication. Content based on factory floor data and real customer design reviews.

Frequently Asked Questions

Can I use Megtron 6 instead of Rogers for 5G mmWave designs?

For frequencies below 15 GHz, Megtron 6 performs adequately with Df of 0.0044 at 10 GHz. Above 28 GHz, Rogers RO4350B or RO3003 provides significantly lower insertion loss.

Is RO4350B compatible with standard FR-4 fabrication processes?

Partially. RO4350B uses thermoset resin (not PTFE) so it can be drilled and plated conventionally, but it requires special lamination parameters and compatible prepregs like RO4450F.

What is the cost difference between RO4350B and Megtron 6?

RO4350B typically costs 3-5x standard FR-4, while Megtron 6 runs 1.5-2x FR-4. For a 6-layer board, this translates to roughly 2-3x price difference per panel.

Which material has better thermal reliability for automotive radar?

RO4350B with Tg above 280C and CTE z-axis of 32 ppm/C outperforms Megtron 6 (Tg 200C, CTE z-axis 45 ppm/C) for high-temperature automotive environments.