3711 ASE Technology Holding Co., Ltd. Announces Subsidiary's Acquisition of Factory Engineering Services from Adlink Technology Inc.

Announcement Date: May 16, 2026 Spokesperson Date: May 15, 2026 Spokesperson Time: 15:57:56 Company Code: 3711 Company Name: ASE Technology Holding Co., Ltd. Subject: Announcement by subsidiary ASE Semiconductor Manufacturing Co., Ltd. regarding the acquisition of factory engineering services for business operations from Adlink Technology Inc. Applicable Clause: Article 20 Date of Occurrence of the Event: May 15, 2026 Description: 1. Name and nature of the underlying asset (e.g., land in XX Section, XX Subsection, Taichung City): Factory engineering for business operations. 2. Date of Occurrence of the Event: 2026/5/4 to 2026/5/15. 3. Date of Board Resolution: Not applicable. 4. Other Approval Dates: Approval Level: General Manager's approval May 15, 2026 5. Quantity of transaction units (e.g., XX square meters, equivalent to XX ping), unit price, and total transaction amount: Transaction quantity: One batch Unit price: NTD 489,508 thousand (pre-tax) Cumulative total transaction amount: NTD 489,508 thousand (pre-tax) 6. Counterparty of the transaction and its relationship with the company (if the counterparty is a natural person and not a related party of the company, disclosure of their name may be exempted): Counterparty: Adlink Technology Inc. Relationship with the company: None 7. If the counterparty is a related party, the reason for selecting the related party as the transaction object, the previous transferor, the relationship between the previous transferor and the company and the counterparty, the previous transfer date, and the transfer amount should also be announced: Not applicable 8. If the ownership of the transaction object has been a related party of the company within the last five years, the related party's acquisition and disposal dates, prices, and its relationship with the company at the time of the transaction should also be announced: Not applicable 9. Estimated disposal gain (or loss) (not applicable to asset acquisition) (if deferred, recognition status should be listed): Not applicable 10. Delivery or payment terms (including payment period and amount), contract restriction clauses, and other important agreements: Delivery or payment terms: Wire transfer or letter of credit payment Contract restriction clauses: None Other important agreements: None 11. Method of determining this transaction (e.g., tender, price comparison, or negotiation), reference basis for price determination, and decision-making unit: Method of determining the transaction and reference basis for price determination: Price comparison and negotiation Decision-making unit: Handled in accordance with the company's approval authority regulations 12. Valuation firm or company name and valuation amount: Not applicable 13. Valuer's name: Not applicable 14. Valuer's professional license number: Not applicable 15. Is the valuation report for a limited price, specific price, or special price: No or not applicable 16. Has the valuation report not yet been obtained: No or not applicable 17. Reason for not yet obtaining the valuation report: Not applicable 18. If there is a significant difference in the valuation result, the reason for the difference and the accountant's opinion: Not applicable 19. Accounting firm name: Not applicable 20. Accountant's name: Not applicable 21. Accountant's professional license number: Not applicable 22. Broker and brokerage fees: None 23. Specific purpose or use of acquisition or disposal: For production and operations 24. Opinions of directors who dissented from this transaction: Not applicable 25. Is this transaction a related party transaction: No 26. Date of approval by supervisors or audit committee: Not applicable 27. Is this transaction for the acquisition of real estate or its right-of-use asset from a related party: No 28. Price evaluated according to Article 16 of the "Regulations Governing the Acquisition or Disposal of Assets by Public Companies": Not applicable 29. If the price evaluated in the preceding item is lower than the transaction price, the price evaluated according to Article 17 of the same regulations: Not applicable 30. Date of previous significant announcement on the same event: Not applicable 31. Other matters to be specified: None