Prospectus: 12M New Shares Rights Offering at KRW 4,125 (KRW 49.5B)

Prospectus 6.0 LB Semicon Co., Ltd. PROSPECTUS June 17, 2026 (Issuer Name) LB Semicon Co., Ltd. (Type and Number of Securities) Registered common shares, 12,000,000 shares (Total Offering/Sale Amount) KRW 49,500,000,000 1. Effective date of the securities registration: June 17, 2026 2. Offering price: KRW 4,125 3. Subscription period: July 29-30, 2026 (existing shareholders); August 3-4, 2026 (general public offering) 4. Payment date: August 6, 2026 5. Locations to inspect the securities registration and prospectus: a. Securities registration: FSC (FSS) DART electronic disclosure system → http://dart.fss.or.kr b. Additional shelf-registration documents: Not applicable c. Prospectus: - Electronic: FSC (FSS) DART electronic disclosure system → http://dart.fss.or.kr - Physical: LB Semicon Co., Ltd. → 138 Cheongbuk Sandan-ro, Cheongbuk-myeon, Pyeongtaek-si, Gyeonggi-do KB Securities Co., Ltd. → 50 Yeouinaru-ro, Yeongdeungpo-gu, Seoul 6. Stabilization or market-making matters: Not applicable The effectiveness of the securities registration for this prospectus does not mean that the government has certified that the contents of the registration are true or accurate, nor that it has guaranteed or approved the value of these securities. Please note that the contents of this prospectus may be amended before the subscription date. (Lead Underwriter) KB Securities Co., Ltd. [Confirmation by Representative Director, etc.] lb_semicon_representative_confirmation_signature_0617.jpg [Main Body] Summary Information 1. Key Investment Risks The key investment risks below are a concise and clear summary of the most important items among the investment risk factors described in the main text of the securities registration, intended to enhance investor understanding. For detailed investment risk factors, please refer to 'Main Text - Part 1 Matters Concerning Offering or Sale - III. Investment Risk Factors.' BUSINESS RISKS a. Risk from domestic and international economic fluctuations According to the World Economic Outlook released by the IMF in April 2026, the 2026 global economic growth forecast was announced at 3.1%, a downward revision of 0.2 percentage points from the January 2026 forecast of 3.3% for 2026. The IMF diagnosed that risks to the global economy remain tilted to the downside, citing prolonged or expanded conflicts, deepening geopolitical fragmentation, a re-evaluation of expectations regarding AI-driven productivity gains, and the re-ignition of trade tensions as key downside factors. According to the Bank of Korea's economic outlook report released in February 2026, this year's growth rate is expected to be 2.0%, higher than the November 2025 forecast of 1.8%, supported by an expanded semiconductor cycle recovery and a better-than-expected global economy, despite the impact of U.S. tariffs and a slow recovery in construction investment. In 2027, growth is forecast at a solid 1.8%, as the domestic recovery continues and exports increase on the back of a global cyclical upturn and expanded semiconductor capacity. The semiconductor back-end (OSAT) business that the company operates as its core business is directly and indirectly affected by domestic and overseas macroeconomic conditions, and a global economic downturn caused by high interest rates, high exchange rates, and low growth could result in shrinkage of capex across the manufacturing sector or deterioration in the company's operating results. For semiconductor back-end companies, the business is closely linked to the semiconductor manufacturing industry cycle, and if economic uncertainty expands, this could lead directly to order delays or declines. In addition, while financial-market uncertainty factors have not been fully resolved, rising credit spreads and similar developments could act as additional risk factors for the company's financial condition, including an increased burden of financing costs related to borrowings and worsening conditions for additional fundraising. This macroeconomic uncertainty can affect overall domestic and international economic conditions and may act as a negative factor for the company's business and performance. Investors are advised to take note of this point. b. Risk from downstream industry cyclicality The semiconductor back-end (OSAT) business operated by the company is closely affected by the cycles of its downstream industries, the semiconductor and display industries, so changes in the cycles of these downstream industries are expected to have direct and indirect effects on the company's consolidated income and financial structure. In particular, the DDI (Display Driver IC) bumping business, which accounts for about 40% of the company's revenue, is directly tied to display panel demand, while non-DDI businesses such as SoC, PMIC and CIS are affected by the non-memory semiconductor market. According to the global semiconductor market outlook released by World Semiconductor Trade Statistics (WSTS), the global semiconductor market in 2026 is forecast at USD 520.1 billion, growing 26.3% compared to 2025. WSTS forecasts that 2026 memory revenue will grow 39% year over year, and that the logic segment, including digital ICs, will also show growth of around 30%. Meanwhile, according to market research firm Precedence Research, the total global display market is forecast to grow from USD 195.4 billion in 2025 to USD 371.6 billion in 2034, at a compound annual growth rate of 7.4%. Nonetheless, if growth in the downstream industry stagnates or the market contracts, this could negatively affect the company's operating performance, and there is a risk of delayed capex across the display industry due to a recurrence of the COVID-19 pandemic. c. Risk from legal and policy changes related to displays and system semiconductors The performance of the company's core system semiconductor back-end business (Driver IC) is highly correlated with the sales volumes of semiconductors and displays. Therefore, the growth of the semiconductor and display markets is highly correlated with the company's earnings growth. Looking at the size of the global display market, it has been stagnant on a value basis due to global economic slowdown and falling LCD panel prices, but on an area basis it has shown steady growth driven by larger TVs and smartphones; the importance of OLED panels is forecast to strengthen, and government support policies for semiconductors and displays exist. However, if future government policy support for displays and system semiconductors is scaled back and the growth of the display and semiconductor markets is weaker than expected, this could negatively affect the company's operating results, so investors are advised to take note. d. Risk from customers bringing semiconductor back-end operations in-house The semiconductor back-end industry is closely related to integrated semiconductor manufacturers such as Samsung Electronics and SK hynix, and has a business structure in which it receives and delivers outsourced back-end work such as semiconductor packaging and testing from integrated semiconductor companies. Generally, semiconductor manufacturers are increasing the proportion of outsourced packaging and testing in order to ease their fixed-cost burden. In particular, the system semiconductor industry has a small-quantity multi-variety production characteristic because the uses of its products and the entities of demand are diverse, which makes efficient cost structures essential. For this reason, in the system semiconductor industry, compared with the memory semiconductor industry, the division and specialization of processes such as fabless, foundry, packaging and testing are more widespread, and the outsourcing share is gradually increasing. According to market research firm Precedence Research, the semiconductor OSAT market is forecast to grow from USD 46.5 billion in 2025 to USD 98.6 billion in 2035, at a 10-year compound annual growth rate of 7.81% from 2025 to 2035. However, due to unexpected internal and external variables such as global regional conflicts and high benchmark interest rate hikes, downstream industry trends in the semiconductor market are unfolding in directions different from the past, and the items affecting supply and demand are also becoming more diverse. In this case, integrated semiconductor companies may modify their management strategies and production processes in ways different from before, taking into account changes in downstream industries. Going forward, in the course of next-generation semiconductor process technology development such as advanced packaging, if the company fails to preemptively respond to the pace of technology development, integrated [Translation truncated]