MICROELECTRONIC MAGNETIC STRUCTURE,
DEVICE INCLUDING THE STRUCTURE, AND METHODS OF FORMING THE STRUCTURE AND DEVICE
CROSS REFERENCE TO RELATED
 This Application claims priority to Provisional Application Serial No. 60/238,994, entitled Imbedded Magnetic Array, filed Oct. 10, 2000.
FIELD OF THE INVENTION
 The present invention generally relates to magnetic structures suitable for electronic components. More particularly, the invention relates to magnetic structures that may be formed within a substrate and to methods of forming the structures.
BACKGROUND OF THE INVENTION
 Magnetic structures are used to form a variety of electronic components such as transformers, inductors, and the like. The magnetic structures may be coupled to or integrated with other electronic components to form electronic devices such as switching power regulators or other integrated circuits.
 Often, magnetic structures used to form electronic devices are available as discrete parts and are integrated with other electronic components by attaching the discrete magnetic component to a printed circuit board and integrating the magnetic component with other components using conductive traces formed on or within the printed circuit board. For example, high current output power supplies (e.g., suitable for supplying power to a microprocessor) such as switching regulators typically include a magnetic inductor attached to a printed circuit board and coupled to other components such as capacitors, diodes, and transistors, which are also coupled to the circuit board.
 Now-known discrete magnetic components and methods of forming electronic devices using now-known magnetic components may be deficient for several reasons. First, the components are typically available only in certain sizes, and thus a device including the magnetic component must be designed using only the available magnetic components-rather than designing the magnetic component to obtain the desired characteristics of the electronic device. Second, discrete magnetic components, which are mounted on a surface of a printed circuit board, often require the largest clearance of all the electronic components that comprise the regulator. In addition, because of the relatively large size, the discrete magnetic components must often be placed relatively far from other components, such as switches, within a power regulator. Placing the magnetic component of a power regulator away from the switches of the regulator is problematic because it requires a signal transmitted through the power regulator to travel additional distance, which in turn may create parasitic resistance and/or inductance within the regulator. Moreover, in the case of multi-phase regulators, which include multiple inductors, attaching a plurality of magnetic structures may be problematic, cumbersome, and relatively expensive. Accordingly, improved magnetic components, which may readily
be configured for a desired application, which occupy relatively little space, and which are relatively easy to handle, are desired.
SUMMARY OF THE INVENTION
 The present invention provides improved magnetic structures suitable for forming electronic devices, devices including the structures, and methods of forming the devices and magnetic structures. More particularly, the invention relates to magnetic structures that may be formed on or embedded in a substrate such as a printed circuit board and devices including the structures.
 The way in which the present invention addresses various drawbacks of the now-known discrete magnetic structures is discussed in greater detail below. However, in general, the improved magnetic structures in accordance with the present invention may be configured for a desired application, occupy relatively little space on a substrate, and are relatively easy to form on or within a substrate.
 In accordance with one embodiment of the present invention, magnetic structures are formed on or within a substrate by forming a layer of magnetic material on or within the substrate, patterning the layer of magnetic material, and etching or machining the material to form the desired structure(s). In accordance with one aspect of this embodiment, multiple layers of magnetic material may be patterned and etched or machined to form the magnetic structure. In accordance with an alternate aspect of this embodiment, a layer of pre-formed magnetic structures may be attached to a portion of the substrate.
 In accordance with a further embodiment of the present invention, an inductor, including a magnetic structure, may be formed on or within a substrate by forming a layer or layers of magnetic material on or within the substrate, and patterning and etching or machining the magnetic material to form a magnetic core. In accordance with one aspect of this embodiment, the conductive winding about the magnetic core is formed by forming conductive plugs or vias coated with conductive material and traces on and within the substrate.
BRIEF DESCRIPTION OF THE DRAWINGS
 A more complete understanding of the present invention may be derived by referring to the detailed description and claims, considered in connection with the figures, wherein like reference numbers refer to similar elements throughout the figures, and:
 FIG. 1 schematically illustrates a switching power regulator in accordance with the present invention;
 FIG. 2a illustrates a top view of a structure including embedded magnetic structures in accordance with the present invention;
 FIG. 2b illustrates, in cross section, the structure of FIG. 2a;
 FIG. 3 illustrates, in cross section, a portion of a power regulator including magnetic structures in accordance with the present invention;
 FIG. 4 illustrates a top cut-away view of inductors formed on a substrate in accordance with the present invention;