Panasonic MEGTRON 6 R-5775 is an ultra-low-transmission-loss, heat-resistant laminate for high-speed multilayer circuit boards. Its matching prepreg is R-5670. The standard R-5775 datasheet reports Df values of 0.002 at 1GHz and 0.004 at 10GHz, but those numbers do not describe every MEGTRON 6 construction or guarantee the loss of a finished PCB channel.
At QFPCB, we select and model MEGTRON 6 by the exact material variant, glass style, resin content, pressed dielectric thickness, copper profile, trace geometry and target frequency. A design that merely says “MEGTRON 6” leaves important purchasing and impedance decisions unresolved.
What Is Panasonic MEGTRON 6 R-5775?
R-5775 is the laminate designation in Panasonic Industry’s MEGTRON 6 family; R-5670 is the associated prepreg. Panasonic describes the system as an ultra-low-loss, highly heat-resistant material for multilayer boards used in networking, wireless and other high-speed infrastructure.
The August 2022 official datasheet, document No.22081031, includes standard R-5775 properties plus detailed construction tables for R-5775(K), R-5670(K), R-5775(G) and R-5670(G). Panasonic publishes R-5775(N)/R-5670(N) separately as the low-Dk glass-cloth version. These suffixes must not be dropped when an exact approved construction matters.
MEGTRON 6 R-5775 Datasheet Values
The following values come from Panasonic Industry document No.22081031. Panasonic states that they are typical, not guaranteed values. The main property specimen is a 29.5mil (0.750mm) Core Type 30 laminate, and electrical conditioning must remain attached to Dk and Df.
| Property | Typical value | Unit | Condition | Test method |
|---|---|---|---|---|
| Tg | 185 / 210 | °C | As received | DSC / DMA |
| Td | 410 | °C | As received | TGA |
| T288, without / with Cu | >120 / >120 | min | As received | IPC-TM-650 2.4.24.1 |
| X/Y-axis CTE, α1 | 14-16 / 14-16 | ppm/°C | Below Tg | IPC-TM-650 2.4.24 |
| Z-axis CTE, α1 / α2 | 45 / 260 | ppm/°C | Below / above Tg | IPC-TM-650 2.4.24 |
| Dk at 1GHz / 10GHz | 3.71 / 3.61 | – | C-24/23/50 | IPC-TM-650 2.5.5.9 / 2.5.5.5 |
| Df at 1GHz / 10GHz | 0.002 / 0.004 | – | C-24/23/50 | IPC-TM-650 2.5.5.9 / 2.5.5.5 |
| Water absorption | 0.14 | % | D-24/23 | IPC-TM-650 2.6.2.1 |
| Peel strength, 1oz H-VLP | 0.8 | kN/m | As received | IPC-TM-650 2.4.8 |
| Flammability | 94V-0 | rating | C-48/23/50 | UL |
R-5775, R-5775(K), R-5775(G) and R-5775(N)
“MEGTRON 6” is a family name, not a complete construction callout. The standard August 2022 sheet gives the general R-5775 property table, then separate frequency/construction tables for R-5775(K) and R-5775(G). Panasonic publishes R-5775(N) separately as the low-Dk glass-cloth version.
For the standard-glass R-5775 sheet, a 54% resin construction using 3313 or 2116 cloth is listed around Dk 3.71 at 1GHz and 3.61 at 10GHz. Higher-resin, thinner constructions show lower typical Dk. The value used for impedance therefore follows the actual glass/resin construction, not the family headline.
R-5775(N) should not be silently substituted for R-5775(K/G). Its low-Dk glass changes dielectric behavior and may affect impedance geometry, skew planning, availability and qualification. Put the exact suffix, copper type, core and prepreg construction in the controlled stackup.
How Glass Style and Resin Content Change Dk
The official construction tables show why a single “MEGTRON 6 Dk” is inadequate. For R-5775(K), examples range from Dk 3.46 at 1GHz for a 2.0mil 1035 core with 65% resin to Dk 3.71 for 3313 or 2116 constructions at 54% resin. By 10GHz, those examples are approximately 3.37 and 3.61 respectively.
The trend is useful, but it is not a universal mixing formula. Glass style, resin content, cured thickness, frequency and test method all change the published result. Fabrication drawings should identify the approved material family and electrical targets while allowing the fabricator to propose a manufacturable construction for review.
Df Is Only One Part of the Channel-Loss Budget
MEGTRON 6 is selected because its dielectric loss is much lower than standard FR-4 and many mid-loss systems. Yet finished-channel insertion loss also includes conductor loss, copper roughness, trace width, dielectric thickness, length, vias, backdrill stubs, pads, connectors and launch transitions.
The datasheet’s H-VLP peel-strength entry is a reminder that copper profile matters. A smooth copper interface can reduce conductor loss, especially as skin depth decreases. Conversely, an unnecessarily narrow trace or rougher copper can consume the margin gained from a lower Df laminate.
For high-speed PCB manufacturing, QFPCB asks for the data rate, rise time or target frequency, channel length, insertion-loss budget, connector model, via topology and allowed copper profile before confirming a material and stackup.
Multilayer and HDI Stackup Review
Panasonic positions the MEGTRON 6 family for high-speed multilayer boards and describes strong HDI and thermal performance. That positioning does not approve every microvia structure. For a multilayer PCB, resin fill, copper balance, registration, lamination cycles and the exact R-5670 prepreg construction still control yield.
An HDI PCB using MEGTRON 6 requires project review of laser-via dielectric thickness, capture-pad geometry, copper filling, sequential lamination and material availability. R-5775 is a high-speed digital laminate rather than a PTFE RF material, so the QFPCB high-frequency-material prohibition on HDI claims is not being applied to redefine it as an RF laminate. Any-Layer HDI remains subject to the actual construction and manufacturing review.
Impedance Modeling With MEGTRON 6
The correct Dk input is construction- and frequency-dependent. QFPCB can provide stackup impedance simulation and technical support for multilayer, hybrid and approved HDI projects, including Any-Layer HDI when the high-speed digital construction passes review. We use the proposed pressed dielectric thickness, glass/resin construction, copper profile, finished copper and trace geometry rather than entering one catalog Dk everywhere.
For an impedance-control PCB, specify single-ended and differential targets, reference layers, trace width/spacing constraints, copper thickness and connector transitions. If the material suffix or prepreg must not change, mark it as controlled rather than leaving it in a purchasing note.
PCB engineer Alan has more than 10 years of PCB CAM engineering experience. Send your MEGTRON 6 stackup and impedance table to [email protected]. This support does not imply an unreviewed tolerance, named simulation software, test coverage or first-pass guarantee.
MEGTRON 6 Versus FR408 or Astra MT77
Material comparisons should start with the channel budget, not a ranking label. Isola FR408 may fit shorter or less loss-sensitive channels where cost, availability or an established qualification matters more than the lowest dielectric loss. Isola Astra MT77 is another low-loss option whose datasheet conditions and constructions must be compared directly.
Do not compare Df values measured at different frequencies or by different methods as if they were identical. Also compare copper profile, glass styles, prepreg availability, thermal data, UL recognition, customer approvals, regional sourcing and the fabricator’s controlled process. A material substitution can require impedance re-targeting and channel-model updates even when headline Dk values look close.
When MEGTRON 6 Is the Wrong Choice
MEGTRON 6 can be unnecessary when a short channel has ample loss margin on a less costly, more widely qualified material. It is also not automatically the right dielectric for an RF antenna, microwave filter or phase-critical circuit; those designs may require frequency-specific RF laminate data and a different manufacturing route.
Selecting R-5775 cannot repair poor return paths, excessive via stubs, connector discontinuities, rough copper or weak launch design. Run the channel analysis first, identify how much loss must be removed, then decide whether the laminate change is technically and commercially justified.
Files Needed for a MEGTRON 6 PCB Quote
- Gerber, ODB++ or IPC-2581 fabrication data and NC drill files
- Layer order, finished thickness and copper weight by layer
- Exact R-5775 variant and R-5670 prepreg requirement
- Approved glass styles, copper profile and substitution restrictions
- Controlled-impedance table with reference layers and tolerances
- Data rate, target frequency, rise time, channel length and loss budget
- Via structure, backdrill requirements, microvia layer pairs and lamination count
- Connector, BGA escape and transition constraints
- Assembly profile, reflow/rework exposure and reliability requirements
- Prototype and production quantities plus certificate or traceability needs
These inputs allow QFPCB to separate official material data from the finished-board performance that must be designed, manufactured and verified.
If the channel loss budget exceeds MEGTRON 6 margin, compare the exact construction with Panasonic MEGTRON 7 R-5785. Match glass type, copper profile, frequency and test method; the family name alone is not a valid substitution rule.
Frequently Asked Questions
What are the Dk and Df values of MEGTRON 6 R-5775?
Panasonic’s standard R-5775 property table reports Dk 3.71 and Df 0.002 at 1GHz, plus Dk 3.61 and Df 0.004 at 10GHz. These are typical values under specified IPC-TM-650 methods and C-24/23/50 conditioning, not universal design values for every glass style or resin content.
What is the difference between R-5775 and R-5670?
R-5775 is the laminate designation and R-5670 is the matching prepreg designation. A multilayer stackup normally uses laminate cores and prepreg bonding layers. The exact suffix, glass style, resin content and cured thickness should be controlled because they influence Dk, impedance, resin filling and manufacturability.
What is the Tg of Panasonic MEGTRON 6?
The R-5775 datasheet reports 185°C by DSC and 210°C by DMA, both as-received typical values. They are not contradictory because DSC and DMA use different measurement principles. Tg does not equal continuous operating temperature, decomposition temperature or automatic approval of a specific assembly profile.
Is MEGTRON 6 suitable for 56G or 112G designs?
It can be a candidate, but the material name alone does not confirm a data rate. Channel length, modulation, insertion-loss limit, copper roughness, vias, connectors, launches and equalization determine performance. Use frequency-dependent material data and model the full channel before freezing R-5775 or another laminate.
Is R-5775(N) the same as standard R-5775?
No. Panasonic identifies R-5775(N)/R-5670(N) as the low-Dk glass-cloth version. Standard R-5775 and the K/G constructions use different published electrical tables. Treat suffixes as controlled design and purchasing information; do not exchange them without impedance, signal-integrity and qualification review.
Can MEGTRON 6 be used for HDI PCB?
Yes, Panasonic positions the family for HDI performance, but QFPCB approves the actual construction rather than the family name. Laser-via dielectric, copper filling, capture-pad geometry, lamination count, registration and material availability must be reviewed. Complex or Any-Layer HDI structures require project-specific engineering confirmation.
Is MEGTRON 6 an RF or microwave laminate?
MEGTRON 6 is primarily positioned as a high-speed, low-loss multilayer material. Some RF structures may use it, but an RF design may require tighter frequency-dependent Dk, phase, thickness and copper data than a general digital datasheet supplies. Do not substitute it automatically for a dedicated RF laminate.
Does lower Df guarantee lower PCB insertion loss?
No. Lower dielectric loss helps, but conductor roughness, trace geometry, channel length, vias, stubs, connectors and launches also contribute. The finished PCB may fail its loss budget despite a low-Df laminate if the interconnect design or copper system consumes the available margin.
Request a MEGTRON 6 Stackup Review
Send QFPCB your MEGTRON 6 variant, fabrication package, loss budget, impedance table, channel lengths, copper-profile requirement and via structure. We will review material availability, stackup feasibility and manufacturing inputs before quotation. Do not freeze the stackup from a single Dk or Df value.
Official sources: Panasonic Industry MEGTRON 6 R-5775/R-5670 datasheet No.22081031 and the Panasonic MEGTRON 6 family page.
If your channel does not require the lower-loss MEGTRON 6 tier, compare the official Dk, Df and thermal data in our MEGTRON 4 R-5725 material guide before selecting the stackup.
