3711 ASE Holding

Disclosure Date: 1150714 Statement Date: 1150713 Statement Time: 172134 Company Code: 3711 Company Name: ASE Holding Subject: Announcement on behalf of subsidiary Siliconware Precision Industries Co., Ltd. regarding acquisition of facility engineering Compliance Clause: Item 20 Factual Date: 1150713 Details: 1. Type of Contract: Facility Engineering 2. Factual Date: 115/7/9 ~ 115/7/13 3. Board Approval Date: Not applicable 4. Other Approval Dates: Approval Level: Approved by General Manager July 13, 115 (2026) 5. Contract Counterparty and Relationship with Company: Sampo Engineering & Construction Co., Ltd., Relationship with Company: None 6. Main Contents of Contract (including total contract value, estimated investment amount, contract period, restrictions, and other important terms): Total Amount: NTD 1,990,358,000; Contract Period: July 9, 115 (2026) to December 31, 117 (2028); Restrictions and Other Important Terms: None 7. Name of Professional Appraisal Firm or Company and Appraisal Result: Not applicable 8. Name of Real Estate Appraiser: Not applicable 9. License Number of Real Estate Appraiser: Not applicable 10. Specific Purpose of Acquisition: For production and operational use 11. Dissenting Director's Opinion on This Transaction: None 12. Whether This Transaction is a Related-Party Transaction: No 13. Date of Supervisor's Approval or Audit Committee's Consent: Not applicable 14. Whether the Appraisal Report is at a Limited, Specific, or Special Price: No or Not applicable 15. Whether Appraisal Report Has Not Yet Been Obtained: No or Not applicable 16. Reason for Not Yet Obtaining Appraisal Report: Not applicable 17. Reasons for Significant Differences in Appraisal Results and Auditor's Opinion: Not applicable 18. Name of Auditor's Firm: Not applicable 19. Name of Auditor: Not applicable 20. Auditor's License Number: Not applicable 21. Previous Date of Material Information Disclosure on the Same Event: Not applicable 22. Other Disclosures: None