ASE Holding Announces Subsidiary SPIL's Acquisition of Facility Engineering Project

1. Type of Contract: Facility Engineering 2. Date of Event: July 13–20, 2026 (Minguo Year 115) 3. Board Approval Date: Not applicable 4. Other Approval Dates: Approval Level: Approved by General Manager Date: July 20, 2026 (Minguo Year 115) 5. Counterparty and Relationship with Company: Sante Engineering Technology Co., Ltd. Relationship: No affiliation 6. Main Contract Contents (including total contract value, estimated investment amount, contract period, restrictions, and other important terms): Total Amount: NT$1,074,236,000 Contract Period: July 13, 2026 (Minguo Year 115) to December 31, 2028 (Minguo Year 117) Restrictions and Other Important Terms: None 7. Name of Professional Appraisal Firm or Company and Appraisal Results: 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 Opinions on the Transaction: None 12. Is this a Related-Party Transaction? No 13. Date of Supervisor Approval or Audit Committee Consent: Not applicable 14. Is the Appraisal Report a Limited, Specific, or Special Price? No or Not applicable 15. Has the Appraisal Report Not Yet Been Obtained? No or Not applicable 16. Reason for Not Yet Obtaining the Appraisal Report: Not applicable 17. Reasons for Significant Differences in Appraisal Results and Auditor's Opinion: Not applicable 18. Name of Accounting 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 Explanatory Matters: None