The Invisible Bottleneck: AI Hunger for “Glass Cloth” Threatens iPhone 18

According to Nikkei Asia, Apple and Qualcomm are grappling with a supply crisis over “glass cloth” used as a core insulating layer in chip substrates, a shortage that could affect the iPhone 18. The material, specifically high-end T-glass, is largely controlled by the Japanese firm Nittobo, prompting Apple to place personnel inside Mitsubishi Gas Chemical’s facilities in autumn 2025 to oversee production and prioritisation.

Apple has also engaged Japanese government officials to mediate and secure a stable supply, while exploring alternative sourcing such as Grace Fabric Technology, though validation processes for secondary-grade cloth are lengthy and challenging. The shortage comes as demand for AI chips drives up orders, with capacity constrained by Nittobo’s tight control and a projected new capacity not online until the latter half of 2027.

The article notes that delays risk impacting the 2026 debut of the iPhone 18 and frames Tim Cook’s push for supply-chain diversification as a response to this vulnerability.