AI Server PCB Supercycle — Global Market First Breakthrough of $100B, Analysis of Structural Bottleneck Benefits for Korean Small and Mid-Sized PCB Companies. Excluding Large Caps (Samsung Electro-Mechanics, LG Innotek), Focused Coverage on Pure Small and Mid-Sized Players.
The Korean small and mid-sized PCB sector is a structural beneficiary of the AI infrastructure supercycle. As the global PCB market surpasses $100 billion for the first time in 2026, the proportion of AI server PCBs is surging from 15% to over 25% year-on-year, reshaping the industry structure itself. FACT
The core investment thesis is "Own the Bottleneck." With the value of PCB per AI server increasing by over 30% and the number of layers increasing from 18 to 32, Korean small and mid-sized companies with irreplaceable technologies such as ultra-high multilayer MLB (Isu Petasys), SOCAMM2 substrates (Simmtech), and FC-BGA (Daeduck Electronics, Korea Circuit) are directly benefiting from the supply bottleneck. INFERENCE
From a valuation perspective, the median Forward PER of the Korean PCB sector at 15.9x is trading at a 40-45% discount compared to global peers (Unimicron 27.9x, TTM 28.6x). Combined with the FY26E sector average operating profit growth rate of +176%, most stocks are extremely undervalued relative to growth, with PEG ratios ranging from 0.02 to 0.23. FACT
US Fed Funds Rate Maintained at 4.25-4.50% (2025.12~), Bank of Korea Lowered to 2.75% (2026.02, 3.00→2.75%). The entry into the BOK easing cycle is structurally favorable for small and mid-sized growth stocks. ISM Manufacturing PMI at 50.3 (2026.03) returning to expansion territory, and the US 10Y-2Y spread is normalizing, retreating recession risk. FACT
PCB, which used to be a traditional mature industry, has started a "second S-curve" with AI as a new growth engine. NVIDIA AI server cabinet demand is doubling from 28,000 units in 2025 to over 60,000 units in 2026, and high value-added segments are redefining the entire industry. FACT
ABF Substrate: Samsung Electro-Mechanics (SEMCO) has pre-arranged all of its 2026 production with Alphabet, Tesla, Apple, AWS, and Broadcom, and the CEO has officially stated that "demand exceeds production capacity by more than 50%." The shortage rate is expected to worsen from 10% in 2026H2 to 42% in 2028. Prices continue to rise by approximately 10% per quarter. FACT (Source: Digitimes 2026.04.08, Korea Herald 2026.04)
CCL (Copper Clad Laminate): Lead time extended to 6 months due to the double bottleneck of copper foil + fiberglass. Copper prices at an all-time high of $13,300/ton, putting pressure on CCL prices to increase by 10-30%. New capacity expansion for AI server-oriented HVLP copper foil in 2026 will only meet 50% of demand. FACT (Source: Digitimes 2026.03~04)
MLB Ultra-High Multilayer: Very few companies globally can mass-produce 52 layers. Isu Petasys has virtually secured a monopolistic position, and big tech companies such as NVIDIA have offered more than double the 2026 volume compared to the previous year. FACT
SOCAMM2 Substrate: SK Hynix officially announced the start of mass production for NVIDIA Vera Rubin on 2026.04.20, and Simmtech is the only substrate company that has obtained mass production certification from the three memory companies (Samsung, SK, Micron). FACT (Source: Aju Economy, ZDNet Korea 2026.04)
Isu Petasys (007660) — Market Cap ₩1.13T · Fwd PER 42.88x · PBR 11.58x
The only company in the world mass-producing MLB 52 layers. North American big tech companies (NVIDIA, Google, Microsoft, Meta, Amazon) have offered more than double the 2026 volume compared to the previous year. Investing ₩50 billion in a new plant in Dalseong, Daegu. FY26E revenue is certain to exceed ₩1 trillion, with operating profit expected to grow by +37%. PBR is the highest in the sector at 11.58x, but technological monopoly and order visibility justify the premium. FACT
Simmtech (222800) — Market Cap 332B · Fwd PER 16.0x · PBR 5.77x
SOCAMM2 Memory 3 Company Exclusive Certification — Currently the only certified substrate company. Mass production is expected to begin in 2026 2Q, generating ₩90 billion+ in new quarterly revenue. FY26E operating profit turnaround of +747% (FY25 11.9B→FY26E 108.5-155B). PEG 0.02, extremely undervalued relative to growth. FACT
Korea Circuit (007810) — Market Cap ₩2.35T · Fwd PER 13.0x · PBR 3.43x
SOCAMM2 + Broadcom FC-BGA Double Leverage. FY26E revenue ₩1.7 trillion, operating profit ₩135.1 billion (+151%). Foreign ownership is unusually low at 4.95% compared to a market cap of ₩2.3 trillion — significant room for future inflows. Cost efficiency is being improved by transferring 100% of domestic production to Vietnam. FACT Additional upside in the second half of the year if Broadcom FC-BGA quality is passed. INFERENCE
Daeduck Electronics (353200) — Market Cap 569B ·