CSC Announces Acquisition of Real Estate by Subsidiary CSC Aluminum Corporation

1. Contract Type: Lease and build. 2. Date of Fact Occurrence: 115/4/30~115/4/30 (2026/4/30~2026/4/30) 3. Board Approval Date: April 30, 2026 4. Other Approval Date: Not applicable 5. Counterparty and Relationship: Chung-Yu Environmental Engineering Co., Ltd.; Group enterprise related party. 6. Main Contract Details (including total contract amount, planned investment amount, and contract period): L2 packaging workshop new construction project; total amount approximately NT$99 million. 7. Professional Appraisal Firm and Result: Not applicable. 8. Real Estate Appraiser Name: Not applicable. 9. Real Estate Appraiser License Number: Not applicable. 10. Specific Purpose of Acquisition: After the L2 packaging workshop is completed, space will be freed up for solid solution furnaces, enhancing operational efficiency. 11. Dissenting Director Opinions: None. 12. Related Party Transaction: Yes. 13. Supervisor Approval or Audit Committee Approval Date: April 30, 2026. 14. Appraisal Report Limited Price, Specific Price, or Special Price: No or not applicable. 15. Appraisal Report Not Yet Obtained: No or not applicable. 16. Reason for Not Obtaining Appraisal Report: Not applicable. 17. Discrepancy in Appraisal Result and Reason, and Accountant's Opinion: Not applicable. 18. Accounting Firm Name: Not applicable. 19. Accountant Name: Not applicable. 20. Accountant License Number: Not applicable. 21. Previous Material Information Release Date for Same Event: Not applicable. 22. Other Remarks: None.