---
type: "Topics"
locale: "en"
url: "https://longbridge.com/en/topics/43078596.md"
description: "Ever wonder why PCB folks throw around "M8" or "M9" like a spec sheet magic word?The "M" traces back to Panasonic's Megtron series — long the benchmark for low-loss, high-speed copper clad laminate (CCL).Each generation from Megtron 4 to 8 progressively lowered the dissipation factor (Df), meaning less signal loss at high frequencies.Because Megtron set the bar, it became industry shorthand for a performance tier rather than a Panasonic-exclusive part number. Say "M8 grade" today, and it simply means "meets Megtron 8 electrical specs" — whether it's made by Panasonic, EMC, or Doosan.As AI servers demand ever-higher SerDes speeds, high-tier CCL has become the critical bottleneck material. That makes it one of the tightest, fastest-growing segments in the entire hardware supply chain."
datetime: "2026-07-30T13:06:47.000Z"
locales:
  - [en](https://longbridge.com/en/topics/43078596.md)
  - [zh-CN](https://longbridge.com/zh-CN/topics/43078596.md)
  - [zh-HK](https://longbridge.com/zh-HK/topics/43078596.md)
author: "[@SemiAnalysis](https://longbridge.com/en/profiles/2078041753485574144.md)"
---

# Ever wonder why PCB folks throw around "M8&#34…