The squeeze starts with an input that appears on no bill of materials: the glass fabric inside the base material. What is behind it, why it will not pass quickly, and what it means for planning.
Rising raw material prices, longer procurement times and limited availability are putting manufacturers and buyers alike under pressure. The starting point is an input that appears on no bill of materials and is negotiated in no specification: the glass fabric inside the base material.
Three processing stages sit between that fabric and a finished board. That is exactly why a price move there reaches the board price late but reliably — and why it helps to understand the mechanism rather than only watch the index.
The chain in four steps
The fabric is impregnated with resin to make prepreg, the prepreg is pressed with copper foil into copper-clad laminate, the laminate is processed into a board. Each stage carries its own inventory and its own contract terms.
So a fabric increase does not come through at once: the plants draw down stock first, then contracts expire, then things are repriced. The same holds in reverse — when the raw material calms down, it takes quarters for that to reach the board price.
Why this time it is demand, not an outage
Earlier fabric shortages were outages: a plant burns, a furnace goes down. The current cycle is a demand effect. AI server demand has pulled weaving capacity onto high-margin low-Dk cloth, and what gets displaced is precisely the standard styles that go into ordinary multilayer boards.
The difference matters in practice: an outage gets repaired, a demand shift does not. It ends only when additional looms are running — and the looms are the real bottleneck.
Three bottlenecks you cannot buy your way past
- Looms: one Japanese manufacturer holds over 90 % of the world market for electronic-cloth looms. Delivery runs 12 to 24 months and the order book is full well beyond that.
- Ultra-fine yarn: only a few producers master the required quality at sufficient volume.
- Qualifying new suppliers: release and certification cycles cannot be shortened, least of all in regulated industries — typically one to two years.
What it means for planning
Availability currently matters more than the last increment of price optimisation. If you are planning series, commit material earlier and build buffer into call-offs; if you are designing now, put the stackup on common fabric styles rather than on a style that happens to be short.
The concrete numbers — price levels by style, month-on-month moves and the horizon for new capacity — we keep current on a page of their own rather than freezing them into an article. Electronic cloth is repricing monthly; treat anything older than a few weeks as stale.