亚洲科技硬件：AI PCB入门（第一部分）- 技术与供应链

Asia Tech Hardware: AI PCB primer (part 1)- technology & supplychain Stocks in PCB/substrate market have been on fire, driven by rising content in AI servers andexpectations of ASP hikes this year. This primer covers MLPCB, HDI and ABF substrate market,plus key raw materials including CCL, T-glass and ABF film. Part 1 focuses on technology trendsand the competitive landscape; Part 2 will focus on company-level dynamics. Alex Wang, CFA+852 2123 2613 Euan McLeish+81 3 5962 9611 The global PCB market size is US$80B+, and AI-driven demand is is set to growanother double-digit again this year.MLPCB (multi-layer PCB) are widely used in serverCPU/GPU motherboard, power and thermal boards, and in switches. Layer counts are risingfrom a mainstream 16L+ layers to over 40L in Vera Rubin midplanes, and 70L+ in RubinUltra backplane. WUS is the primary MLPCB supplier for Nvidia’s GB300 rack, followed byUnimicron and Victory Giant (VGT). TTM, ISU, and Gold Circuit Nvidia’s HGX and ASIC serversand switch, alongside several emergingtier‑2Taiwanese vendors. David Dai, CFA+852 2918 5704 Shirley Yang, CFA+852 2123 2660 HDI demand (c.US$15bn) is also accelerating, with its share of the PCB market risingroughly 5ppt last year to around 20%.HDI for AI servers (e.g. compute tray in the GB300rack) requires more layers, more microvias, and higher thermal robustness than smartphoneHDI. Compared to Hopper server, the wider adoption HDI adoption in Blackwell rack hasroughly doubled the content value of HDI+PCB per GPU to US$300, benefiting HDI suppliersVGT and Unimicron. Ethan Xu+852 2123 2634 Hao Wang, CFA+852 2123 2627 On the materials side,next‑generationsolutions for 2027 are now under evaluation.CCL (Copper-Clad Laminate) represents c.30% of PCB cost and is made up of copper foil,resin, and glass fiber fabric. AI servers and switches use low/ultra-low dielectric (Dk) glassfiber and HVLP copper foil for cleanerhigh‑speedsignaling. The industry has migrated fromM6 CCL to M8 in the past three years, and is moving to M8.5/M9 next year.New‑generationCCL should command singificantly higher ASPs, reflecting more advanced materials andslower yieldramp‑up,which supports the pricing power of leaders such as Doosan and EMC. Mufei Gao+81 3 6777 6995 Jack Lin+852 2123 2683 Juho Hwang+852 2123 2632 Rising package sizes and manufacturing complexity in AI accelerators are drivingABF substrate demand.ABF substrate cost depends on the package size, substratelayer count, and manufacturing techniques. Each AI accelerator generation increases bothlayer count and package area, as vendors integrate more logic dies and HBM stacks intoa single package. Intel’s EMIB-T should further enhance the value capture of substratemanufacturers. New materials and packaging techniques including glass core substrateand CoWoP could eventually enable larger HPC package size, or improve thermal & powerperformance, but we don’t expect mass production in the next few years. ABF substrate ASP are likely to rise in 1Q26 due to T-glass shortage.Low‑CTEglassfiber (or T-glass) minimizes substrate expansion when temperature swings in AI chips. Marketleader Nittobo achieves a CTE of 2.8 x10-6/℃,vs. 3.2 or above for peers. We expect secondsources like Taiwan Glass and Taishan Fiberglass to have only limited supply for AI chipsthis year.Ajinomoto is close to a monopolist supplier of the eponymous Build Up Filmused in ABF substrate, with mid 20’s% top line growth driven by the combination of IC chipdemand, substrate layer count & area expansion, and Ajinomoto’s pricing power. BERNSTEIN TICKER TABLE INVESTMENT IMPLICATIONS We rate Unimicron Outperform, PT = NT$270.00.We rate Ajinomoto Outperform, PT = JPY5,000.00.We rate Ibidem Outperform, PT = JPY8,250.00. DETAILS OVERALL PCB MARKET The global PCB market size is US$80B+, and AI-driven demand is is set to grow another double-digit again this year.The PCB market, valued US$80B-90B, consists of a wide array of products. Roughly half of the market is taken by rigid PCB, andthe remaining portion is split among flexible printed circuit (FPC), high-density interconnect (HDI), and IC substrate. Following thesignificant corrections post-COVID, the PCB market saw a steady growth since 2024. Following 2025 strong rebound, Prismarkexpects PCB market to maintain a mid-single-digit growth for the next two years. The estimates have upside potential as the latestreport from TPCA (Taiwan Printed Circuit Association) suggests PCB market will grow in the mid-teens this year. (Exhibit 4) By applications, the consumer sector (including smartphones, PC, etc.) represents 1/3 of the PCB market, while the server/storage sector, currently 18% of the market, is expected to outpace the average with an 11% CAGR through 2029, reaching 22%mix in 2029E, according to Prismark. (Exhibit 5) Exhibit 6 shows the use case of different types of PCB. Taking AI server for example, the IC chip leverages ABF substrates inFCBGA (flip-chip BGA) packages.