Claims:1. An apparatus comprising:‎
a substrate with a plurality of layers including a top layer, one or more intermediate layers and a ‎bottom layer; and
ferromagnetic material applied to a first of the one or more intermediate layers in an area ‎underneath a magnetic source disposed on an outer surface of the top layer; ‎
wherein the ferromagnetic material is to provide a shield for signal routing traces in one or more ‎other intermediate layers or the bottom layer underneath the first intermediate layer, from a magnetic ‎field produced by the magnetic source.‎
, Description:CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present patent application claims the benefit of U.S. Non-Provisional Patent Application No. 17/088,135, filed November 03, 2020, and titled: “FERROMAGNETIC MATERIAL TO SHIELD MAGNETIC FIELDS IN SUBSTRATE”, which is incorporated herein by reference in its entirety.

Technical Field
[0002] Embodiments of the present disclosure generally relate to the field of printed circuit boards (PCB), and in particular to shielding areas in lower layers of the PCB from magnetic fields.

Background
[0003] Circuitry routing within PCBs underneath inductors and other electromagnetic interference (EMI) emitting components may have noise induced into signals carried in the circuitry.

Brief Description of the Drawings
[0004] Embodiments will be readily understood by the following detailed description in conjunction with the accompanying drawings. To facilitate this description, like reference numerals designate like structural elements. Embodiments are illustrated by way of example and not by way of limitation in the figures of the accompanying drawings.
[0005] FIG. 1A-1G show side views of various examples of laminating ferrite into a PCB structure to create magnetic shielding for areas in lower layers within the PCB structure, in accordance with various embodiments.
[0006] FIG. 2A-2B show top-down views of circuit routing on a PCB in a legacy implementation, in accordance with various embodiments.
[0007] FIG. 3 is a process for applying ferromagnetic material to shield magnetic fields in a substrate, in accordance with various embodiments.
[0008] FIG. 4 schematically illustrates a computing device 400 in accordance with one embodiment.

Detailed Description
[0009] Embodiments of the present disclosure are directed to an apparatus that includes a substrate with a plurality of layers including a top layer, one or more intermediate layers and a ‎bottom layer, and ferromagnetic material applied to a first of the one or more intermediate layers in an area ‎underneath a magnetic source disposed on an outer surface of the top layer, where the ferromagnetic material is to provide a shield for signal routing traces in one or more ‎other intermediate layers or the bottom layer underneath the first intermediate layer, from a magnetic ‎field produced by the magnetic source.‎