Ultra-Low-Loss Laminate

Isola Astra MT77

Dk 3.00 | Df 0.0017 @ 10 GHz — engineered for 56G/112G PAM4 channels where every dB of insertion loss matters.

3.00

Dk @ 10 GHz

0.0017

Df @ 10 GHz

200°C

Tg (DSC)

360°C

Td

What Is Isola Astra MT77?

Isola Astra MT77 is an ultra-low-loss, spread-glass-reinforced laminate designed for the most demanding high-speed digital and RF applications. Its proprietary resin system delivers a dissipation factor of just 0.0017 at 10 GHz — rivaling Panasonic Megtron 6 while offering competitive pricing and broader availability.

With a Tg of 200°C and Td of 360°C, Astra MT77 combines exceptional electrical performance with the thermal reliability needed for lead-free assembly in high-layer-count designs up to 40+ layers.

Ultra-Low Df

0.0017 at 10 GHz minimizes insertion loss on long high-speed traces

Spread Glass Reinforcement

Reduces fiber weave effect for consistent impedance across differential pairs

High Thermal Stability

200°C Tg and 360°C Td support lead-free reflow and high-reliability builds

Material Properties

PropertyValueTest Method
Dielectric Constant (Dk)3.00 ±0.05IPC-TM-650, 10 GHz
Dissipation Factor (Df)0.0017IPC-TM-650, 10 GHz
Glass Transition (Tg)200°CDSC
Decomposition Temp (Td)360°CTGA, 5% wt loss
CTE Z-axis~45 ppm/°CTMA
FlammabilityUL 94 V-0UL
ReinforcementSpread glass
Resin SystemUltra-low-loss thermoset

Technical Highlights

112G PAM4 Ready

Supports 112 Gbps PAM4 SerDes channels with less than 0.8 dB/inch insertion loss at 28 GHz Nyquist frequency, enabling longer trace lengths without retimers.

5G mmWave Compatible

Low and stable Dk across frequency enables accurate impedance control for 5G FR2 antenna feed networks and beamforming arrays up to 40 GHz.

High Layer Count

Excellent resin flow and spread glass construction enable reliable lamination in 30–50 layer stackups common in switch and router backplanes.

Astra MT77 vs. Competing Materials

PropertyAstra MT77Megtron 6Tachyon 100G
Dk @ 10 GHz3.003.403.02
Df @ 10 GHz0.00170.0020.0015
Tg (°C)200185200
Td (°C)360400360
Relative Cost$$$$$$$$$

Astra MT77 delivers Megtron 6-class performance at a meaningfully lower cost, making it the value leader for high-volume data center builds.

Target Applications

Data Center Switches

51.2T and 102.4T switch backplanes with 112G SerDes

AI Server Interconnect

GPU-to-GPU fabric boards for AI training clusters

5G Macro Radio

Base station transceiver boards and antenna feeds

High-Speed Networking

400G/800G optical module host boards

Radar & Defense

Phased array antenna panels and RF front-ends

Test & Measurement

High-bandwidth oscilloscope and analyzer main boards

Design Guidance

Stackup Recommendations

  • Use spread glass cores (1067/1080) for signal layers to minimize fiber weave skew
  • Pair with Astra MT77 prepreg for consistent Dk across the stackup
  • Target 3.5–4.0 mil dielectric for 100Ω differential impedance

Processing Tips

  • Bake panels at 105°C for 2h before lamination to remove moisture
  • Use VLP or HVLP copper foil (Rz ≤ 3 µm) to preserve low-loss advantage
  • Back-drill stubs to within 8 mil of signal layer for 56G+ channels

Why AtlasPCB for Astra MT77?

Isola Authorized

Direct material sourcing with full lot traceability and mill certs

Signal Integrity Review

Free DFM and impedance simulation on every high-speed order

Tight Tolerances

±7% impedance control with TDR verification on every panel

Frequently Asked Questions

Common questions about Isola Astra MT77 PCB fabrication

What is the dielectric constant of Isola Astra MT77?

Astra MT77 has a Dk of 3.00 ±0.05 measured at 10 GHz, making it one of the lowest-loss laminates available for high-speed digital and mmWave applications.

How does Astra MT77 compare to Megtron 6?

Astra MT77 delivers comparable or better electrical performance to Panasonic Megtron 6 (Df 0.0017 vs 0.002) at a lower cost point and with better global availability through Isola distribution.

What applications is Astra MT77 best suited for?

Astra MT77 excels in 56G/112G PAM4 SerDes channels, data center switch backplanes, AI server interconnects, and 5G macro radio base stations where ultra-low insertion loss is critical.

What is the glass transition temperature of Astra MT77?

Astra MT77 has a Tg of 200°C (DSC) and a decomposition temperature (Td) of 360°C, providing excellent thermal reliability for lead-free assembly and high-layer-count builds.

Can AtlasPCB fabricate PCBs with Isola Astra MT77?

Yes. AtlasPCB maintains stock agreements with Isola for Astra MT77 in standard thicknesses. We support builds from 4 to 40+ layers with controlled impedance and back-drilling.

Ready to Build with Astra MT77?

Upload your Gerber files and get a quote within 24 hours. Our engineers will review your stackup for optimal signal integrity.

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