[Unimicron] Announcement on Acquisition of Facility Engineering Related Materials

1. Name and nature of the underlying asset (e.g., land located in Section XX, Taichung City): Facility Engineering 2. Date of occurrence of the event: 2026/04/16~2026/05/15 3. Date of approval by the Board of Directors: Not applicable 4. Other approval dates: Approval level: Chairman of the Board. May 15, 2026 5. Transaction volume, unit price, and total transaction amount: Volume: 1 batch; Total amount: NT$387,085,000 6. Counterparty and its relationship with the Company: Liwei Technology Engineering Co., Ltd.; Non-related party 7. Where the counterparty is a related party, reasons for choosing them and details of previous transfers: Not applicable 8. Where the owner of the subject matter within the past five years was a related party of the Company, details of acquisition/disposal dates and prices: Not applicable 9. Expected disposal profit (or loss): Not applicable 10. Delivery or payment conditions, restrictive covenants, and other important stipulations: Payment according to order terms; Restrictive covenants and other important stipulations: None 11. Method of determining the transaction, reference basis for price determination, and decision-making unit: Transaction method: Price negotiation. Reference basis: Market price. Decision-making unit: Approved according to the company's procurement management regulations. 12. Name of the professional appraiser and appraisal amount: Not applicable 13. Name of the professional appraiser: Not applicable 14. Professional appraiser's certificate number: Not applicable 15. Is the appraisal report a limited price, specific price, or special price: No or not applicable 16. Has an appraisal report not yet been obtained: No or not applicable 17. Reason for not yet obtaining an appraisal report: Not applicable 18. Reason for any significant discrepancy in appraisal results and CPA opinion: Not applicable 19. Name of the CPA firm: Not applicable 20. Name of the CPA: Not applicable 21. CPA certificate number: Not applicable 22. Broker and brokerage fee: Not applicable 23. Concrete purpose or use of the acquisition or disposal: For production and operational use 24. Opinions of dissenting directors regarding this transaction: Not applicable 25. Is this transaction a related party transaction: No 26. Date of approval by the supervisor or audit committee: Not applicable 27. Does this transaction involve acquiring real estate or right-of-use assets from a related party: No 28. Appraised price according to Article 16 of the Regulations Governing the Acquisition and Disposal of Assets: Not applicable 29. If the appraised price in the preceding item is lower than the transaction price, the appraised price according to Article 17: Not applicable 30. Date of previous major message announcement regarding the same event: Not applicable 31. Other matters to be specified: None