M9 CCL: What the Grade Means and How Ultra-Low-Loss Laminates Compare

“M9 CCL” is industry shorthand for the newest class of ultra-low-loss copper-clad laminates, one step below the loss of “M8”-class materials, aimed at the fastest AI server, switch and backplane boards. It is not a grade defined by IPC or any standards body, and no laminate maker’s datasheet is certified as “M9.” What you can compare are the makers’ own numbers: for example, Doosan lists its DS-7409DYQ at a Df of 0.0006 and a Dk of 2.5 at 10 GHz, against about 0.0012–0.0016 for Panasonic’s Megtron 8. This guide explains what the M-grade labels mean, compares official datasheet values, covers the fabrication issues of these materials, and lists what to specify. For other laminates, see our PCB materials guide.

1. What Does “M9” Mean?

The “M” levels (M4, M6, M7, M8, M9) grew out of Panasonic’s MEGTRON numbering and are now used across the industry to describe loss tiers: the higher the number, the lower the dielectric loss. They are convenient for conversation and market reports, but:

• They are not defined in IPC-4101 or IPC-4103, the laminate and prepreg specifications; those use numbered slash sheets with minimum property values (IPC-4103B contents, November 2017).
• Different makers and buyers draw the tier boundaries differently.
• A board specification that says “M9” without a product name leaves the material open.

So on a drawing, name the exact product and suffix, not the tier.

2. How Do the Lowest-Loss Laminates Compare?

Official values from each maker’s current product page or datasheet. Methods and frequencies differ, so use the table to place materials, not to calculate loss:

Sources: Doosan product pages for DS-7409DYQ, DS-7409DQN and DS-7409DJN+; EMC EM-892K2 datasheet (July 2024); Panasonic R-5795 datasheet (July 2024). Typical values, not guaranteed.

The DS-7409DYQ row shows what the next tier looks like on paper: a 10 GHz Df under half of the M8-class values in the table (with the caveat that test methods differ), a lower Dk of 2.5, and very low in-plane expansion (6 ppm/°C X/Y, against 9–10 for the other DS-7409 versions). Doosan also lists DS-7409DYQ and DQN as halogen-free.

3. Why Do These Materials Need Special Glass and Copper?

At this loss level the resin is no longer the only factor. Standard E-glass has much higher loss than the resin, so ultra-low-loss laminates use low-Dk, low-loss glass cloth; some of the newest use quartz-based glass. Copper roughness also adds conductor loss, so these boards are built with very-low-profile copper (HVLP grades). Both glass and copper should be named on the drawing or approved from the fabricator’s proposal; otherwise they may be substituted.

4. What Are the Fabrication Challenges?

These laminates usually go into the hardest boards to build:

• High layer counts and thick boards, often with large panels, where registration and lamination control dominate yield.
• Drilling: harder, low-loss glass cloths wear drill bits faster; fabricators adjust drill parameters and hit counts.
• Backdrilling to remove via stubs on high-speed nets.
• Hybrid stackups, with ultra-low-loss cores only on the fastest layers, which need compatible materials and expansion.
• Material supply: the newest grades can have long lead times or allocation; confirm availability before you commit a design.

For the overall AI server material picture, see our NVIDIA Blackwell PCB material guide, and for design rules, our high-speed PCB design rules.

5. When Do You Need an M9-Class Laminate?

When the channel loss budget cannot be met with an M8-class material plus smooth copper, short routing and good via design. That usually means the longest, fastest channels: backplanes and midplanes, and long routes on high-speed switch and accelerator boards. For many boards, a well-designed M8-class or Tachyon 100G stackup is enough at lower cost and with better availability.

Make the decision with a channel model that uses each candidate’s construction-specific Dk and Df and your copper roughness, and check material availability at the same time.

6. How Do You Specify an Ultra-Low-Loss Laminate?

How Can We Help?

Send your stackup with the exact laminate you want and your Gerber files; we will confirm material availability, constructions and impedance in the quote, which comes back within 2 hours for bare boards. We build multilayer PCBs up to 40 layers and HDI PCBs, and you can compare candidate materials with our PCB material selector. For high-layer-count builds on advanced laminates, see our PCB manufacturing services.

Conclusion

“M9” is an industry label for the next ultra-low-loss tier, not a standard. Compare real products on their datasheets: Doosan’s DS-7409DYQ lists Df 0.0006 and Dk 2.5 at 10 GHz, less than half the listed Df of M8-class materials such as Megtron 8 and EM-892K2, though the test methods differ. These materials need low-loss glass, smooth copper and careful fabrication, and supply can be tight. Specify the exact product and suffix, and choose this tier only when your channel model needs it. Contact us for a quote.

FAQ

What is M9 CCL? An industry term for copper-clad laminates in the lowest-loss tier currently marketed, beyond M8-class materials. It is not an IPC grade.

Which laminates are M9-class? Makers position their newest ultra-low-loss products in this tier; Doosan’s DS-7409DYQ, with Df 0.0006 at 10 GHz, is one example from the datasheets above. Confirm the tier with the maker for any specific product.

Is M9 an IPC standard? No. IPC-4101 and IPC-4103 use slash sheets, not M-grades.

What is the difference between M8 and M9? Lower loss and, in the newest products, lower Dk and lower in-plane expansion, typically achieved with different glass. The exact difference depends on the products you compare.

Can any PCB fabricator build M9-class boards? These boards need experience with high layer counts, backdrilling and hybrid stackups, plus access to the material; confirm both before you order.