After four years of planning, TSMC is now finally going to make older iPhone processors in the US, but it's not and never will be a true return to American manufacturing.

Apple is already testing the initial batch of processors produced for its devices by TSMC Arizona, reports Nikkei Asia. To begin with, the tests intend to compare the Arizona output to see if the quality is similar to chips produced in TSMC’s cutting-edge fabs in Taiwan.