AI servers are driving a shortage of high-end circuit board material, which is great news for Taiwan's three big copper-clad laminate makers and a rising cost for everyone buying from them.

• Copper-clad laminate is the base material every server motherboard and switch board is built on, and AI chips need higher grades of it that lose less signal.
• Makers are upgrading from M6 and M7 to M8 and M9 for 2026 AI servers, and supply cannot keep up, so prices keep going up every quarter.
• The squeeze starts upstream: glass fiber cloth, resin and copper foil plants are running nearly flat out, leaving no slack in the chain.
• Elite Material, Taiwan Union and Iteq have all seen revenue jump sharply, with profit margins widening as more high-end material ships, and new capacity already booked out past 2028.
• The main worry is CPO, a technology that moves signals by light instead of copper; talk in September that cheaper material would be enough sent all three stocks down hard in one day.

Outlook: Big banks expect CPO to arrive slowly and do little damage before 2028, so high-end laminate should stay in short supply and keep getting more expensive, though the share prices will likely stay jumpy.