Amkor Technology (AMKR) said late Tuesday it is moving ahead with phase 2 of its advanced packaging and test campus in Arizona, raising the planned investment to about $12 billion.

The expansion is expected to add 60,000 square meters of cleanroom space, bringing the campus total to about 93,000 square meters. Together, the first two phases are expected to support more than 3,500 Arizona-based employees.

Construction of the second phase is expected to begin in late 2027 and be completed by the end of 2029, the company said.