Embodiments include package substrates and method of forming the package substrates. A package substrate includes a first encapsulation layer over a substrate, and a second encapsulation layer below the substrate. The package substrate also includes a first interconnect and a second interconnect vertically in the first encapsulation layer, the second encapsulation layer, and the substrate. The first interconnect includes a first plated-through-hole (PTH) core, a first via, and a second via, and the second interconnect includes a second PTH core, a third via, and a fourth via. The package substrate further includes a magnetic portion that vertically surrounds the first interconnect. The first PTH core has a top surface directly coupled to the first via, and a bottom surface directly coupled to the second via. The second PTH core has a top surface directly coupled to the third via, and a bottom surface directly coupled to the fourth via.