AT Semicon Co., Ltd. engages in the provision of testing services for semiconductor equipment. It operates through following business divisions: Semiconductor Packaging, Turn-Key Service, and Test Solutions. The Semiconductor Packaging division offers multi chip package, system in package, CMOS image sensor, board circuits, fine pitch ball grid array, quad flat no-leads package, quad flat package, thin small outline package. The Turn-Key division provides back-end, turn-key services, wafer and final tests. The Test Solutions division offers tests on memory devices and system integrated circuit. The company was founded on July 27, 2001 and is headquartered in Icheon-si, South Korea.