KRW 49.8B Rights Offering: 12M New Shares for Facility & Working Capital

Material Event Report (Decision on Paid-in Capital Increase) LB Semicon Co., Ltd. Material Event Report / Exchange Filing Obligation To: Financial Services Commission / Korea Exchange Date: May 15, 2026 Company Name: LB Semicon Co., Ltd. CEO: Lee Dae-gyo Head Office: 138 Cheongbuk Sandan-ro, Cheongbuk-eup, Pyeongtaek City Phone: 031-680-1600 Website: http://www.lbsemicon.com Responsible Person: Kim Jung-gyu, Head of Management Division (031-680-1600) Decision on Paid-in Capital Increase 1. Type and Number of New Shares - Common shares: 12,000,000 - Other shares: - 2. Par Value per Share (KRW): 500 3. Total Issued Shares Before Increase - Common shares: 58,083,006 - Other shares: - 4. Purpose of Fund Raising - Facility funds (KRW): 30,000,000,000 - Business acquisition funds: - - Operating funds (KRW): 19,800,000,000 - Debt repayment funds: - - Other corporate securities acquisition: - - Other funds: - 5. Method of Capital Increase: Shareholder allocation followed by public offering of forfeited shares 6. Issue Price of New Shares - Confirmed price: - - Tentative price (common): KRW 4,150 - Confirmation date: July 24, 2026 7. Issue Price Calculation Method: See Item 24 (a) 8. Record Date for New Share Allocation: June 19, 2026 9. New Shares Allocated per Existing Share: 0.2066008773 10. Preferential Allocation Ratio for Employee Stock Ownership Association: - 11. Subscription Schedule - Employee Stock Association: - - Existing Shareholders: July 29, 2026 – July 30, 2026 12. Payment Date: August 6, 2026 13. Forfeited Share Treatment Plan: See Item 24 (b) 14. Dividend Accrual Date for New Shares: January 1, 2026 15. Scheduled Share Certificate Delivery Date: - 16. Scheduled Listing Date for New Shares: August 21, 2026 17. Lead Underwriter: KB Securities Co., Ltd. 18. Transferability of Preemptive Rights: Yes - Listing of preemptive rights certificates: Yes - Brokerage for preemptive rights certificates: KB Securities Co., Ltd. 19. Board Resolution Date: May 15, 2026 - Outside directors attending: 1 (none absent) - Audit Committee attendance: Attended 20. Securities Registration Statement Required: Yes 21. Reason for Exemption: - 22. Short-Sale Restriction Period for Subscription: Yes; Start May 18, 2026; End July 24, 2026 23. KFTC Notification Required: Not applicable 24. Other Information for Investment Judgment A. Method of Calculating New Share Issue Price 1) Tentative issue price: Using May 14, 2026 (the trading day immediately preceding the board resolution) as the base date, the reference price is the lower of (i) the arithmetic average of the 1-month, 1-week, and base-date volume-weighted average prices on KOSDAQ, and (ii) the base-date VWAP. A 20% discount applies via the formula below. Amounts below the quote unit are rounded up to the quote unit; if below par value, par value is used. * Tentative issue price = Reference price × (1 - discount rate) / [1 + (capital increase ratio × discount rate)] 2) First issue price: Using the third trading day before the record date as the base date, calculated using the same VWAP methodology and 20% discount. ▶ First issue price = Reference price × (1 - discount rate) / [1 + (capital increase ratio × discount rate)] 3) Second issue price: Using the third trading day before the start of existing-shareholder subscription as the base date, the reference price is the lower of (i) the average of the 1-week and base-date VWAPs, and (ii) the base-date VWAP. A 20% discount applies. ▶ Second issue price = Reference price × (1 - discount rate) 4) Final issue price: The lower of the first and second issue prices. However, pursuant to Article 165-6 of the Financial Investment Services and Capital Markets Act and Article 5-15-2 of the Regulations on Issuance and Disclosure of Securities, if the lower of the first and second issue prices is less than the price calculated by applying a 40% discount to the VWAP from the 3rd to 5th trading day prior to subscription, then the latter price (40% discount) is used as the final issue price. ▶ Final issue price = MAX[MIN(First, Second), 60% of reference price] 5) The final issue price will be determined on the third trading day before the first day of existing-shareholder subscription and disclosed on DART on July 27, 2026, and announced on the company website (www.lbsemicon.com) in lieu of individual notice. B. Subscription Result Allocation Method 1) Existing Shareholder Subscription (Preemptive Rights Subscription): Shareholders recorded as of 18:00 on the record date (June 19, 2026) will be allocated 0.2066008773 shares per share held (fractional shares discarded). Allocation may change due to treasury share movements before the record date. 2) Excess Subscription: Any forfeited or fractional shares remaining after existing-shareholder subscription will be allocated to existing shareholders who applied for excess subscription (excess ratio: 0.2 shares per allocated new share) on a pro-rata basis. Fractional shares are discarded. If excess subscription is less than forfeited/fractional shares, 100% allocation applies. (i) Subscription limit = Preemptive rights certificate limit + Excess subscription limit (ii) Preemptive rights certificate limit = Number of preemptive rights certificates held (iii) Excess subscription limit = Preemptive rights subscription limit × Excess subscription ratio (20%) 4) Public Offering Subscription: Forfeited and fractional shares remaining after existing-shareholder and excess subscription will be publicly offered by the lead underwriter. Pursuant to Article 9(2)(3)-(4) of the Securities Underwriting Business Regulations, at least 10% will be allocated to high-yield, high-risk investment trusts, at least 30% to venture company investment trusts, and the remaining 60% to individual subscribers and institutional investors (including collective investment business operators) without distinction. If any group has under-subscription, those shares are allocated to over-subscribed groups. (i) Integrated allocation method: Allocations to each subscriber are based on the integrated subscription competition ratio (lead underwriter's total subscription volume divided by public offering allocation share count). (ii) If public offering subscription exceeds offering share count, pro-rata allocation by competition ratio with rounding (5사6입) applies. [Translation truncated]