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

1. Type of Contract: Facility Engineering 2. Event Date: 08/12/2026 ~ 09/02/2026 3. Board Approval Date: Not applicable 4. Other Decision Dates: Decision Level: Approved by General Manager September 2, 2026 (Minguo Year 115) 5. Counterparty and Relationship with the Company: SFA Engineering Corporation, Relationship with the company: None 6. Main Contents of the Contract (including total amount, expected investment amount, start and end dates): Restrictive clauses and other important agreements: Total Amount: NT$542,453,000; Contract Period: August 12, 2026 to December 30, 2028; Restrictive Clauses and Other Important Agreements: None 7. Name of Professional Appraiser 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 Opinions on This Transaction: None 12. Is this transaction a related-party transaction? No 13. Date of Supervisor Approval or Audit Committee Consent: Not applicable 14. Is the appraisal report limited price, specific price, 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 accountant's opinion: Not applicable 18. Name of Accounting Firm: Not applicable 19. Name of Accountant: Not applicable 20. Accountant’s License Number: Not applicable 21. Previous date of material information disclosure regarding the same event: Not applicable 22. Other Statements: None