Unimicron Acquires Factory Engineering-Related Data

1. Name and nature of the subject matter (e.g., land located in Section XX, Subsection XX, North District, Taichung City): Factory engineering

2. Date of occurrence: October 20, 2025 (R.O.C. Year 114) to June 24, 2026 (R.O.C. Year 115)

3. Board approval date: Not applicable

4. Other approval dates: Approval level: Approved by Chairman June 24, 2026 (R.O.C. Year 115)

5. Quantity of transaction units (e.g., XX square meters, equivalent to XX ping), unit price, and total transaction amount: Quantity: One batch; Total transaction amount: TWD 309,509,900

6. Counterparty and its relationship with the company (if the counterparty is a natural person and not a related party of the company, name disclosure may be omitted): Yamasei Kōgyō Co., Ltd.; Non-related party

7. If the counterparty is a related party, state the reason for selecting the related party, the previous transferor, the relationship among the previous transferor, the company, and the counterparty, the previous transfer date, and transfer amount: Not applicable

8. If the owner of the subject matter was a related party of the company within the past five years, disclose the date, price, and relationship with the company at the time of acquisition and disposal: Not applicable

9. Estimated gain (or loss) on disposal (not applicable for asset acquisition) (if deferred, provide a table showing recognition): Not applicable

10. Delivery or payment terms (including payment periods and amounts), contractual restrictions, and other important agreements: Payment according to purchase order terms; Contractual restrictions and other important terms: None

11. Method of transaction determination (e.g., bidding, price comparison, negotiation), reference basis for price determination, and decision-making unit: Transaction method: Negotiation Price determination basis: Market conditions Decision-making unit: Determined under company procurement management regulations

12. Name of professional appraisal firm or company and appraisal amount: Not applicable

13. Name of professional appraiser: Not applicable

14. Professional appraiser license number: Not applicable

15. Whether the appraisal report is for a limited, specific, or special price: No or not applicable

16. Whether an appraisal report has not yet been obtained: No or not applicable

17. Reason for not obtaining the appraisal report: Not applicable

18. Reasons for significant discrepancies in appraisal results and auditor's opinion: Not applicable

19. Name of accounting firm: Not applicable

20. Name of accountant: Not applicable

21. Accountant license number: Not applicable

22. Broker and brokerage fees: Not applicable

23. Specific purpose or use of the acquisition or disposal: For production and operational use

24. Opinion of any director who objected to the transaction: Not applicable

25. Whether this transaction is a related-party transaction: No

26. Date of supervisor approval or audit committee consent: Not applicable

27. Whether the transaction involves acquiring real estate or right-of-use assets from a related party: No

28. Valuation price under Article 16 of the "Regulations on the Acquisition or Disposal of Assets by Publicly Issued Companies": Not applicable

29. Valuation price under Article 17 of the same regulations, if the valuation under the previous item is lower than the transaction price: Not applicable

30. Previous date of major information disclosure on the same event: Not applicable

31. Other explanatory matters: None