In an embodiment, an electromagnetic device, comprises a substrate a substrate comprising a dielectric layer and a first conductive layer; at least one dielectric structure comprising at least one non-gaseous dielectric material that forms a first dielectric portion that extends outward from the first side of the substrate, the first dielectric portion having an average dielectric constant and an optional second dielectric portion that extends into an optional via. The at least one dielectric structure is bonded to the substrate by at least one of: a mechanical interlock between the second dielectric portion and the substrate due to the at least one interlocking slot comprising a retrograde surface; an intermediate layer located in between the dielectric structure and the substrate having a roughened surface; or an adhesive material located in between the dielectric structure and the substrate. A method of making the device can comprise injection molding a dielectric composition onto the substrate to form the dielectric substrate.