NVIDIA's Rubin and Rubin Ultra platforms are continuously enhancing GPU-to-GPU interconnect bandwidth and board-level signal density. This evolution means PCBs are no longer merely traditional carrier boards but have become the core platform responsible for high-speed interconnection, power distribution, and signal integrity.
Correspondingly, the material system is also undergoing an upgrade cycle. Copper-clad laminates (CCL) are progressing from M4/M6 grades to M7/M8/M9. Copper foil is advancing from HVLP1/2 to HVLP3/4/5 specifications. Electronic glass fabric is transitioning from standard 7628/Low-Dk1 to Low-Dk2, T-glass, and Q-glass.
Zheshang Securities posits that the focus for AI server PCBs may be shifting gradually from "downstream demand" to "whether upstream materials can meet the requirements for low loss, high reliability, and high yield." The firm's key viewpoints are outlined below.
HVLP Copper Foil: High-End Demand Scales Up, Window for Domestic Substitution Opens
The demand for low-profile copper foil for high-speed signals is continuously rising. AI servers and high-end switches are driving HVLP3 and HVLP4 to become the mainstream upgrade path.
Overseas supply remains dominated by Japanese manufacturers like Mitsui Metals, which holds approximately 60% share in HVLP2+ and about 80% in HVLP5. High-end supply is highly concentrated with long capacity expansion cycles.
Domestically, Anhui Tongguan Copper Foil Group Co.,Ltd. has achieved mass production capability for HVLP1-4, with HVLP5 currently in the R&D and sampling stage.
The core point of interest in the copper foil segment lies in the introduction of a second domestic supplier for HVLP4, a development with relatively high certainty.
Electronic Glass Fabric: A Notable Supply Bottleneck with Strong Alpha Potential
Electronic glass fabric determines the dimensional stability, dielectric loss, and thermal expansion control of CCL, serving as the "skeleton" for high-speed PCBs.
High-end electronic fabric supply is highly concentrated. Nitto Boseki holds about a 90% share in T-glass, with high shares also in NER/Low-Dk2. Capacity expansion is constrained by the availability of high-end looms, process yield rates, and lengthy customer qualification cycles, suggesting new supply will be slow to materialize.
Price-wise, the spread between standard 7628 and Low-Dk2 fabric exceeds 20 times, with Q-glass prices reaching even higher. The price transmission chain has already moved from electronic fabric to CCL, PCB, and server ODM.
In the quartz Q-glass segment, Hubei Feilihua Quartz Glass Co.,Ltd. is one of the few domestic companies with a fully independent supply chain from "quartz sand to quartz fiber to Q-glass."
Domestic players like Grace Fabric Technology Co.,Ltd., International Composite Materials, and Sinoma Science & Technology are accelerating the introduction of Low-Dk and Q-glass. Notably, Grace Fabric Technology's average electronic fabric price in Q1 2026 increased 117% year-over-year, with net profit attributable to shareholders surging 354%.
Zheshang Securities views electronic glass fabric as one of the segments with a relatively pronounced supply-demand gap and stronger alpha characteristics among the three key materials.
Resin: Domestic M9 Production from Zero to One, Offering Relative Elasticity
Resin determines core electrical properties of CCL such as Dk, Df, and Tg. The generational upgrade from M7 to M9 has long been led by overseas manufacturers like Panasonic and Mitsubishi Gas Chemical.
Domestic manufacturers have now entered the verification and small-batch qualification phase. Sichuan Em Technology Co.,Ltd. has developed systems including hydrocarbon, BMI, PPO, and active ester, achieving mass supply for M9 resin. Its high-speed resin revenue in Q1 2026 reached 258 million yuan, a 131% year-over-year increase.
Compared to copper foil and electronic fabric, resin's short-term price elasticity is weaker. However, starting from a low base for M9, the logic for domestic substitution is relatively clear, offering greater long-term elasticity.
The key tracking variable for the resin segment is the qualification pace of M9/M10 materials at leading CCL manufacturers and end customers.
Key Risk Factors
AI demand falling short of expectations; accelerated capacity expansion by overseas giants leading to slower-than-expected domestic substitution; technological substitution risks from glass substrates/optical interconnects; raw material price volatility; and potential price wars triggered by overly rapid industry capacity expansion.
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