Benefiting from the sustained growth in AI computing and high-end applications‌, Mitsubishi Gas Chemical (MGC) has issued a notice stating that due to shortages in raw materials for low thermal expansion coefficient (Low CTE) glass fabric and a surge in order demand, the lead time for BT (Bismaleimide Triazine) materials has significantly extended. Industry sources indicate that, coinciding with the peak procurement period for NVIDIA and AMD, a scramble for AI semiconductor materials is imminent. As BT prices rise, high-end ABF substrate manufacturers like Unimicron and Nan Ya PCB, control IC designers such as Silicon Motion and Phison, and IC packaging firms like ASE Group are expected to see price increases

According to the latest industry chain updates, MGC recently informed Taiwanese substrate manufacturers that the lead time for certain BT materials (NS/NSF Low CTE Glass) with thicknesses of only 0.04mm or 0.06mm has reached ‌16 to 20 weeks‌, more than double the normal period. For standard specifications like the NSA series, lead times have generally extended to ‌4 to 6 weeks‌. Additionally, Resonac (formerly Showa Denko) has also reported supply shortages. With the two major BT suppliers facing supply chain issues, the lead times for glass fabric and copper-clad laminate (CCL) have lengthened, prompting manufacturers to actively seek alternative sources.

MGC attributes the extended lead times to multiple factors, including ‌a surge in orders, insufficient supply of raw glass fabric, and stricter quality inspection processes‌. These issues have become critical bottlenecks limiting the production capacity of high-end substrate-based packaging (SBT).

Industry experts explain that BT materials are primarily categorized into ‌NS and NSF series‌. The NS series represents the standard grade, while the NSF series uses ‌E-Glass or enhanced Low CTE Glass materials‌, offering higher reliability and suitability for more demanding high-end packaging applications.

‌Low CTE Glass‌ refers to glass fiber fabric reinforced with a low thermal expansion coefficient (CTE), providing excellent dimensional stability—particularly crucial for advanced process chip packaging. Ultra-thin materials with thicknesses of ‌0.04mm or 0.06mm‌ are especially critical for compact, high-integration components like ‌high-density SiP modules and eMMC/UFS storage control chips‌.

‌Supply Chain Disruption Effects‌

BT materials are core raw materials for high-end substrate-based packaging (SBT). The current delays in lead times are directly impacting SBT supply, which in turn affects the production schedules of downstream chips and modules.

Industry insiders describe this as a classic ‌"material disruption effect"‌: from shortages in glass fabric raw materials to constrained BT material production capacity, and further delays in substrate manufacturing and packaging schedules. This interconnected supply chain issue may ultimately lead to ‌delays in control chips and module shipments‌, with the risk of shortages gradually escalating.