Exhibit 8(a) Subsidiaries A. ASE Test, Inc., a corporation organized under the laws of the Republic of China; B. ASE Test Holdings Ltd, a corporation organized under the laws of the Cayman Islands, and wholly-owned subsidiary, ISE Labs, Inc., a corporation organized under the laws of the State of California, U.S.A. ISE Labs, Inc. has four subsidiaries: (i) ISE Labs Hong Kong Limited, a corporation organized under the laws of Hong Kong S.A.R.; (ii) ASE Technology Pte Limited, a corporation organized under the laws of Singapore; (iii)ISE Technology, Inc., a corporation organized under the laws of the State of California, U.S.A.; and (iv) Digital Testing Services Inc., a corporation organized under the laws of the State of California, U.S.A. C. ASE Test Finance Limited, a corporation organized under the laws of Mauritius. D. ASE Holding (Singapore) PTE Ltd., a corporation organized under the laws of Singapore, and its wholly owned subsidiary, ASE Electronics (M) Sdn. Bhd, Inc., a corporation organized under the laws of Malaysia.