Batch fabrication of radial anisotropy toroidal inductors

Many high-performance magnetic materials for integration of power magnetics are anisotropic. This poses a challenge for toroidal cores in which the flux direction varies around the circumference. Applying a radial field during deposition or annealing of a toroidal core can result in radial anisotropy that allows these materials to be used effectively in toroids. A design is presented for a radial field fixture that can produce many radial field regions using only a few permanent magnets, to enable fabrication of many toroidal inductors on a single substrate. A fabrication process is also described.