This application provides a planar transformer and a switching power adapter. The planar transformer includes a PCB winding and two magnetic cores. The two magnetic cores wrap two sides of a winding body of the PCB winding to form a closed magnetic loop. A first group of welding points is disposed on a primary-side wire side of the PCB winding, and a second group of welding points is disposed on a secondary-side wire side of the PCB winding. The planar transformer is directly welded to an external circuit board by using the first group of welding points and the second group of welding points. In this way, no pin needs to be welded on the PCB winding board. In addition, the planar transformer can be vertically installed on the external circuit board by using the first group of welding points and the second group of welding points.

An electric field-reducing insulating layer is described for an inductive coil. In some examples, a first coil having at least one first winding is arranged for being driven at a first voltage. A solid insulating layer is adjacent the first coil and has a first surface facing the first coil. The first surface of the solid insulating layer has a first groove between the first winding and the insulating layer, having a width that is smaller than a diameter of the electrical wire. The first groove forms a pocket between the first winding and the solid insulating layer.

An inductor includes a coil that is provided in a component body. A first end of the coil is connected to a first outer electrode, and a second end of the coil is connected to a second outer electrode. The coil includes a plurality of coil conductor layers that are provided in a width direction. Each coil conductor layer is substantially spirally formed with the number of turns being greater than or equal to about one turn. The height of the component body is greater than the width of the component body.

A multilayer coil component includes a multilayer body formed by stacking a plurality of insulating layers and including a coil built therein, and first and second outer electrodes electrically connected to the coil. The coil is formed by electrically connecting a plurality of coil conductors stacked together with the insulating layers. The multilayer coil component further includes, inside the multilayer body, first and second connecting conductors. The first connecting conductor connects between a portion of the first outer electrode covering the first end face, and a coil conductor facing the portion. The second connecting conductor connects between a portion of the second outer electrode covering the second end face, and a coil conductor facing the portion. Concerning the length direction, the first and second connecting conductors each have a length from about 2.5% to about 7.5% of the length of the multilayer body.

A module substrate antenna includes: a laminate in which a plurality of ferrite layers are stacked; antennal coils provided on surfaces of the respective ferrite layers; a connection pad connected to an external circuit; and a lead wire provided between the laminate and the connection pad. In the laminate, the antenna coils are two types of the antenna coils, and the two types of the antenna coils are alternately stacked.

An inductive switch comprises an inductor that has a primary metallic winding having a boundary configured in shape of a figure eight, such as in two loops, and a plurality of secondary metallic windings arranged within the boundary of the primary metallic winding. The inductive switch includes a plurality of switches, each switch arranged in series with a respective one of the plurality of secondary metallic windings. An equal number of the secondary windings is arranged within each loop. A tunable inductor comprises at least one main metallic loop and at least one secondary metallic loop, wherein the at least one secondary metallic loop comprises a switch that is arranged to configure the at least one secondary metallic loop into at least one shorted metallic loop or at least one closed metallic loop. The at least one shorted loop is floating.

A multilayer coil component including an element assembly that includes an insulator portion and a coil embedded in the insulator portion and composed of a plurality of coil conductors electrically connected to each other, an extension portion disposed at each end portion of the coil, and an outer electrode disposed on the surface of the insulator portion and electrically connected to the extension portion. The thickness of the coil conductor in the extension portion of the coil is about 1.05 times or more and 2.0 times or less (i.e., from about 1.05 times to 2.0 times) the thickness of the coil conductor in a winding portion of the coil.

A sintered material contains Fe in an amount of from 8 mol % to 37 mol % in terms of Fe.sub.2O.sub.3, Zn in an amount of from 30 mol % to 60 mol % in terms of ZnO, Cu in an amount of from 1 mol % to 7 mol % in terms of CuO, Ni in an amount of from 3 mol % to 17 mol % in terms of NiO, and Si in an amount of from 7 mol % to 28 mol % in terms of SiO.sub.2. A mole ratio (SiO.sub.2/Fe.sub.2O.sub.3) of the SiO.sub.2 to the Fe.sub.2O.sub.3 is from 0.2 to 3.5. The sintered material contains B in an amount of from 0.05 mol parts to 0.5 mol parts.

A coil component according to one or more embodiments includes a base body having first to sixth surfaces, and a coil conductor including a winding portion that extends around a coil axis intersecting the first and second surfaces. The winding portion includes first, second, third, and fourth portions facing the third, fourth, fifth, and sixth surfaces, respectively when viewed from a direction of the coil axis. The radii of curvature of the first and second portions are both smaller than the radii of curvature of the third and fourth portions. When viewed from the direction of the coil axis, the distance between the first portion and the third surface and the distance between the second portion and the fourth surface are both larger than the distance between the third portion and the fifth surface and the distance between the fourth portion and the sixth surface.

Embodiments may include inductors with embedded magnetic cores and methods of making such inductors. In an embodiment, an integrated circuit package may include an integrated circuit die with a multi-phase voltage regulator electrically coupled to the integrated circuit die. In such embodiments, the multi-phase voltage regulator may include a substrate core and a plurality of inductors. The inductors may include a conductive through-hole disposed through the substrate core and a plugging layer comprising a dielectric material surrounding the conductive through-hole. In an embodiment, a magnetic sheath is formed around the plugging layer. In an embodiment, the magnetic sheath is separated from the plated through hole by the plugging layer. Additionally, a first layer comprising a dielectric material may be disposed over a first surface of the magnetic sheath, and a second layer comprising a dielectric material may be disposed over a second surface of the magnetic sheath.