Patent Publication Number: US-2021193360-A1

Title: Inductor having high current coil with low direct current resistance

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application is a continuation of U.S. patent application Ser. No. 15/692,134, filed Aug. 31, 2017, which claims the benefit of U.S. Provisional Patent Application No. 62/382,182, filed Aug. 31, 2016, the entire contents of which are incorporated by reference as if fully set forth herein. 
    
    
     FIELD OF INVENTION 
     This application relates to the field of electronic components, and more specifically, inductors and methods for making inductors. 
     BACKGROUND 
     Inductors are, generally, passive two-terminal electrical components which resist changes in electric current passing through them. An inductor includes a conductor, such as a wire, wound into a coil. When a current flows through the coil, energy is stored temporarily in a magnetic field in the coil. When the current flowing through an inductor changes, the time-varying magnetic field induces a voltage in the conductor, according to Faraday&#39;s law of electromagnetic induction. As a result of operating based on magnetic fields, inductors are capable of producing electric and magnetic fields which may interfere with, disturb and/or decrease the performance of other electronic components. In addition, other electric fields, magnetic fields or electrostatic charges from electrical components on a circuit board can interfere with, disturb and/or decrease the performance of the inductor. 
     Some known inductors are generally formed having a core body of magnetic material, with a conductor positioned internally, at times with the conductor formed as a wound coil. Examples of known inductors include U.S. Pat. No. 6,198,375 (“Inductor coil structure”) and U.S. Pat. No. 6,204,744 (“High current, low profile inductor”), the entire contents of which are incorporated by reference herein. Attempts to improve designs and improve the economy of building inductors are commonplace. Thus, a need exists for a simple and cost effective way to produce consistent inductors, including those with inductance lower than lull, while improving direct current resistance. 
     SUMMARY 
     An inductor and method for making the same is disclosed herein. An inductor may comprise a coil formed from a conductor. The coil may have two leads extending from opposite ends of the coil. A body surrounds the coil and portions of the first lead and the second lead. The leads may be wrapped around the body to create contact points, such as surface mount terminals, on an exterior surface of the inductor. 
     A method for making the inductor is also provided. A conductor, such as a metal plate or strip or wire, may be formed in the shape of a coil and two leads coming from opposite ends of the coil. The coil may be formed into a specific shape, such as a serpentine or meandering shape, and may preferably be formed having an “S” shape. The conductor may be folded, bent, and/or stamped to form the shape of the coil and two leads. A body of the inductor surrounds the coil, and may be pressed around the coil, leaving the leads sticking out from the body. The leads may then be bent to wrap around the body to form contact points at one external surface of the body. 
     In one aspect, the present invention provides for a flat inductor coil having a shape with leads formed as a unitary piece by stamping a sheet of metal, such as copper. It is appreciated that other conductive materials as are known in the art, such as other materials used for coils in inductors, may also be used without departing from the teachings of the present invention. Insulation may also be used around or between parts of the coil and/or leads if needed for particular applications. The lead portions are aligned along a generally straight path and may have a certain width. The coil may include portions that extend outside of the width of the leads, preferably curved or positioned away from a center of the coil, with the portions connected by a connection portion that runs at an angle across the center of the coil. The coil and leads may initially lie in a plane during manufacturing, such as when formed from a flat piece of metal. The leads may ultimately be bent around and under an inductor body that surrounds the coil. All parts of the coil preferably may lie in a plane in an embodiment of a finished inductor. An inductor body is pressed around and houses the coil. 
     The coil extending between and connecting the leads has a shape. In a preferred embodiment, the coil joins the opposite leads (or lead portions), and generally comprises a first curved portion and a second curved portion. The curved portions preferably curve away from and/or around the center of the coil, and thus may be considered “outwardly” curving. Each curved portion of the coil may extend along a part of the circumference of a circular path curving around the center of the central portion. Each curved portion has a first end extending from one of the leads, and a second end opposite the first end. A central portion, or connection portion, extends at an angle between each second end of the first and second curved portions, traversing the center of the central portion. This creates a serpentine coil which may have an “S” shape when viewed from above or below. 
     Multiple coil layers may be provided. Insulation may be positioned between the multiple coil layers. A coil according to the invention may be formed as a flat, rounded, or oblong shaped piece of metal. 
     In one aspect of the present invention, the coil and leads of the present invention are preferably formed, such as by stamping, as a flat, complete unitary piece. That is, no interruptions or breaks are formed in the coil from one lead to the opposite lead. The leads and coil are formed at the same time during the manufacturing process by stamping. The coil does not have to be joined, such as by welding, to the leads. In other embodiments, the leads are formed separately and joined to the coil. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates an isometric view of an inductor in partial transparency according to the invention; 
         FIG. 2  illustrates an end view of the inductor of  FIG. 1  shown from a lead end; 
         FIG. 3  illustrates an end view of the inductor of  FIG. 1  shown from a non-lead end; 
         FIG. 4A  illustrates a view of the inductor of  FIG. 1  shown from the top in partial transparency; 
         FIG. 4B  illustrates a side view of inductor of  FIG. 1  viewed from the lead edge; 
         FIG. 4C  illustrates a side view of inductor of  FIG. 1  viewed from the non-lead edge; 
         FIG. 5  illustrates schematically a method of making an inductor according to an embodiment of the present invention; 
         FIG. 6  illustrates a leadframe formed at the stamping step in the method of  FIG. 5 ; 
         FIG. 7  illustrates a top down perspective leadframe formed at the stamping step in the method of  FIG. 5   
         FIG. 8  illustrates a part formed at the pressing step in the method of  FIG. 5 ; 
         FIG. 9  illustrates a top down perspective of a part formed at the pressing step in the method of  FIG. 5 ; 
         FIG. 10  illustrates a part formed at the pressing step in the method of  FIG. 5 ; 
         FIG. 11A  illustrates a top down perspective of a part formed at the pressing step in the method of  FIG. 5 ; 
         FIG. 11B  illustrates a side perspective of a part formed at the pressing step in the method of  FIG. 5 ; 
         FIG. 12  illustrates a leadframe with embodiments of an inductor coil according to the invention; 
         FIG. 13  illustrates a top view of the leadframe and inductor coils of  FIG. 12 ; 
         FIG. 14  illustrates a leadframe with embodiments of an inductor coil according to the invention; 
         FIG. 15  illustrates a top view of a leadframe with embodiments of an inductor coil according to the invention; 
         FIG. 16  illustrates another embodiment of a leadframe and coil according to the present invention; 
         FIG. 17  illustrates a perspective view of an assembled inductor according to an embodiment of the present invention; 
         FIG. 18A  and B illustrate an assembled inductor according to the present invention; 
         FIG. 19  illustrates inductor shown with second body in see-through and core and body removed; 
         FIG. 20  illustrates a top view of a coil from an assembled inductor with other parts of the inductor  3100  removed; 
         FIG. 21  illustrates a bottom view of a coil from an assembled inductor with other parts of the inductor  3100  removed; 
         FIGS. 22A-B  illustrates a body from an assembled inductor with other parts of the inductor removed; 
         FIG. 23  illustrates connections of insulated coils via welding and/or soldering. 
         FIG. 24  shows an isometric view of an example coil of an inductor; 
         FIG. 25  shows a side view of an example coil of an inductor; 
         FIG. 26  shows a side view of an example body with inductor leads formed around the sides of the core; 
         FIG. 27  shows a side view of an example core, where the body has been made transparent to see the coil inside, with inductor leads formed around the sides of the core; 
         FIG. 28  shows an isometric view of an example body with inductor leads formed around the sides of the core; 
         FIG. 29  shows an isometric view of an example body, where the core has been made transparent to see the coil inside, with inductor leads formed around the sides of the core; 
         FIG. 30  shows the bottom perspective of an example body with leads formed; 
         FIG. 31  shows an isometric view of an example conductor with multiple coils formed; 
         FIG. 32  shows an isometric view of an example conductor with coils and parts attached; 
         FIG. 33  shows an example process for manufacturing an inductor according to one embodiment; 
         FIG. 34A  shows an isometric view of an example folded conductor; 
         FIG. 34B  shows an front perspective of an example folded conductor; 
         FIG. 34C  shows an front perspective of an example folded conductor with insulation; 
         FIG. 35  shows an isometric view of an example inductor coil made from folded conductor; 
         FIG. 36  is an isometric view of an example inductor coil made from splayed folded conductor; 
         FIG. 37  is an isometric view of an example inductor coil made from folded conductor with formed leads; 
         FIG. 38  is an isometric view of an example body, where the core has been made transparent to see the coil inside, with inductor leads formed around the sides of the core; 
         FIG. 39  is a top perspective of an example body, where the core has been made transparent to see the coil inside, with inductor leads formed around the sides of the core; 
         FIG. 40  is an isometric view of an example coil made from splayed folded conductor with formed leads; 
         FIG. 41  is an isometric view of an example body, where the core has been made transparent to see the coil inside, with inductor leads formed around the sides of the core; 
         FIG. 42  is a top perspective of an example body, where the core has been made transparent to see the coil inside, with inductor leads formed around the sides of the core; 
         FIG. 43  is an isometric view of an example coil made from splayed folded conductor with formed leads; 
         FIG. 44  is an isometric view of an example body, where the core has been made transparent to see the coil inside, with inductor leads formed around the sides of the core; 
         FIG. 45  is a top perspective of an example body, where the core has been made transparent to see the coil inside, with inductor leads formed around the sides of the core; 
         FIGS. 46A-D  illustrate an example process of manufacturing an inductor according to one embodiment; 
         FIGS. 47A-D  illustrate an example process of manufacturing a component for an inductor according to one embodiment; 
         FIG. 48  illustrates an example process of manufacturing an inductor according to one embodiment; 
         FIGS. 49A-D  illustrate an example process of manufacturing a component for an inductor according to one embodiment; 
         FIGS. 50A-F  illustrate an example process of manufacturing an inductor according to one embodiment; and 
         FIGS. 51A-H  illustrate an example process of manufacturing an inductor according to one embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Certain terminology is used in the following description for convenience only and is not limiting. The words “right,” “left,” “top,” and “bottom” designate directions in the drawings to which reference is made. The words “a” and “one,” as used in the claims and in the corresponding portions of the specification, are defined as including one or more of the referenced item unless specifically stated otherwise. This terminology includes the words above specifically mentioned, derivatives thereof, and words of similar import. The phrase “at least one” followed by a list of two or more items, such as “A, B, or C,” means any individual one of A, B or C as well as any combination thereof. It may be noted that some Figures are shown with partial transparency for the purpose of explanation, illustration and demonstration purposes only, and is not intended to indicate that an element itself would be transparent in its final manufactured form. 
       FIG. 1  shows an example of an inductor  3100  according to an embodiment described herein, including a shaped coil  3150  formed from a conductor, such as a metal plate, sheet or strip. A shaped coil  3150  may be shaped in a unique configuration that provides for increased efficiency and performance in a small volume and that is simple to manufacture. The coil  3150  and leads  3140   a  and  3140   b  are preferably initially formed by stamping a conductive sheet, such as a copper sheet, which may be flat and will produce a flat coil, as shown for example in  FIG. 6 . It is appreciated that the surfaces of the coil  3150  may be somewhat or slightly rounded, bowed or curved based on the process used to form the coil  3150 , and the side edges may be rounded or curved. Acceptable metals used for forming the coil and leads may be copper, aluminum, platinum, or other metals for use as inductor coils as are known in the art. As used herein, “flat” means “generally flat,” i.e., within normal manufacturing tolerances. It is appreciated that the flat surfaces of the coil  3150  may be somewhat or slightly rounded, bowed, curved or wavy based on the process used to form the coil  3150 , and the side edges may be somewhat or slightly rounded, bowed, curved or wavy, while still being considered to be “flat.” 
     After stamping, leftover copper strips referred to as carrier strips or frame portions remain, with at least one of the strips having progressive holes at the opposite ends of the leads. The holes may be used for alignment in connection with manufacturing equipment. The stamped copper coil, leads and frame portions may be referred to collectively as a “leadframe.” Examples are shown in  FIGS. 6-11 . Initially, such as during manufacturing, the shaped coil and leads may lie in the same plane. Each lead  3140   a  and  3140   b  will ultimately be bent around the inductor body, with a lead contact portion  3130  bent underneath the bottom of the inductor body. The leads  3140   a  and  3140   b  and coil  3150  are preferably formed as a unitary piece, without a weld. 
     In an embodiment shown in  FIGS. 1, 4A, 5 and 6 , the coil  3150  comprises a serpentine or meandering coil provided as an “S” shaped coil or “S-coil,” when viewed from the top as oriented in the relevant Figures. The coil  3150  has a central portion  3151  crossing diagonally through the middle of the coil. A first curved portion C 1  has a first end  3152  extending from one of the leads  3140   b,  and a second end  3153  curving around the center of the coil  3150 . A second curved portion C 2  has a first end  3155  extending from the other of the leads  3140   a,  and a second end  3154  curving around the center of the coil  3150  in an opposite direction from the first curved portion C 1 . Each curved portion forms an arc encircling part of the center of the coil  3150 . The curved portions may each run along a circumferential path about the center. 
     The coil  3150  may have a central portion  3151  that may be formed as a flat, straight strip, running from the second end  3153  of the first curved portion C 1  and across the center of the coil  3150  to the second end  3154  of the second curved portion C 2 . This central portion  3151  completes the “S” shape. 
     This S-coil or “S” shape is illustrative of a preferred embodiment. Other configurations are also contemplated, as will be discussed in part below, including arc, Z-coil or N-coil configurations. A coil configuration that extends along a meandering path between leads, with a portion of the coil crossing the mid-line or central portion of the coil or an inductor body, would be considered to be a “serpentine” coil. For example, and without limitation, an S-coil, Z-coil, N-coil, and other shaped coils having meandering paths traced from one lead to the other lead are considered to be “serpentine” coils. A serpentine coil may be distinguished from a “winding” coil formed from a wire that encircles a central portion of an inductor core, but does not have a portion crossing or traversing the central portion or a central line of an inductor core. 
     As shown in  FIGS. 4A and 7 , a serpentine coil  3150  of the invention may have a first path P 1  extending toward a first direction from one side of the inductor toward the opposite side, such as extending from a side of the inductor including the lead  3140   b  toward an opposite side of the inductor including the lead  3140 a. In a preferred embodiment, the first path P 1  is a curved or arced path curving away from a central portion of the coil. 
     A second path P 2  continues from the first path P 1  and extends toward a second direction, crossing a central line LA of the coil. In a preferred embodiment, the second path P 2  slopes diagonally across the center and central line LA of the coil from the side where the first path P 1  ends back toward the side where the first path P 1  began, such as extending from a side of the inductor including the lead  3140   a  back toward an opposite side of the inductor including the lead  3140   b.  The second path P 2  may be a generally straight path along most of its length. 
     A third path P 3  continues from the second path P 2  and extends in a third direction from one side of the inductor toward the opposite side, such as extending from a side of the inductor including the lead  3140   b  toward an opposite side of the inductor including the lead  3140   a.  In a preferred embodiment, the third path P 3  is a curved or arced path curving away from a central portion of the coil. In a preferred embodiment, the first and third directions are generally the same, while curving in opposite directions, and also both differ from the second direction. The combination of path P 1 , P 2  and P 3  is a preferably contiguous serpentine path, uninterrupted and formed from the same conductor. 
     The first and third path P 1  and P 3  may trace curved paths, straight paths or combinations of curved and straight paths. For example, as shown in an alternate embodiment in  FIG. 16 , an “N”-shaped coil may trace a first path P 1  that is generally straight from a first side of the inductor to an opposite side, a second path P 2  running diagonally across a center line L A  back toward the first side, and a third path P 3  that is generally straight from a first side of the inductor to an opposite side along most of the lengths of those paths. 
     In the arrangements of the coil having an “S”, “N” or “Z”-shape, spaces or gaps are provided between the various portions of the coil, such as between the curved portion C 1  and the central portion  3151 , and between the curved portion C 2  and central portion  3151 . In the embodiments having an “S”-shape, the spaces or gaps have a generally semi-circular shape, as shown in  FIGS. 4A, 7 and 25 and 39 . In the “N”-shaped embodiment as shown in  FIG. 16 , the spaces or gaps have a generally triangular shape. In a “Z”-shaped coil, the spaces or gaps would also have a generally triangular shape. 
     The shape of the coil  3150  is designed to optimize the path length to fit the space available within the inductor while minimizing resistance and maximizing inductance. The shape may be designed to increase the ratio of the space used compared to the space available in the inductor body. In an embodiment of the invention, coil  3150  is preferably flat and oriented essentially in a plane. 
     The “S” shape optimizes the inductance and resistance values compared to other non-coil conductor configurations. A  1212  package size (approximately 0.12″×0.12″×0.04″) with the S-coil may produce inductance values in the range of 0.05 uH at 2.2 mΩ A  4040  package size (approximately 0.4″×0.4″×0.158″) with the S-coil may produce inductance values in the range of 0.15 uH at 0.55 mΩ. The  1616  package size with the S-coil may produce inductance values of 0.075 uH and the  6767  package size with the S-coil may produce inductance values of 0.22 uH. 
     According to the illustrative embodiment shown in  FIGS. 1-4 , showing the inductor body in partial transparency so as to view the interior, a finished inductor  3100  according to the invention includes an inductor body shown in partial transparency formed about, pressed over or otherwise housing the coils and at least parts of the leads, including a first body portion  3110  and a second body portion  3120 . As illustrated in  FIGS. 1-4C , a first body portion  3110  and a second body portion  3120  sandwich, are pressed around or otherwise house the shaped coil  3150  and parts of the leads  3140   a  and  3140   b  to form the finished inductor  3100 . From the sides as shown in  FIG. 2  and  FIG. 3 , inductor  3100  may be seen with the first body portion  3110  on the bottom and the second body portion  3120  on the top. 
     In the illustrated embodiment of  FIG. 2  and  FIG. 3 , which are shown as partially transparent, first body portion  3110  and second body portion  3120  are shown as separate or discrete portions used to form the finished inductor  3100 , although a single, unitary overall body may be used. In alternative implementations, any number of body portions may be used. The body may be formed of a ferrous material. The body may comprise, for example, iron, metal alloys, or ferrite, combinations of those, or other materials known in the art of inductors and used to form such bodies. First body  3110  and second body portion  3120  may comprise a powdered iron or similar materials, as will be further discussed. Other acceptable materials as are known in the art of inductors may be used to form the body or body portions, such as known magnetic materials. For example, a magnetic molding material may be used for the body, comprised of a powdered iron, a filler, a resin, and a lubricant, such as described in U.S. Pat. No. 6,198,375 (“Inductor coil structure”) and U.S. Pat. No. 6,204,744 (“High current, low profile inductor”). While it is contemplated that first body portion  3110  and second body portion  3120  are formed in similar fashion and of the same materials, first body portion  3110  and second body portion  3120  may be formed using different processes and from distinct materials, as are known in the art. 
     The first body portion  3110  and second body portion  3120  surround the coil and parts of the leads, and may be pressed or over-molded around the coil  3150 , initially leaving exposed parts of the leads  3140   a  and  3140   b  until they are folded underneath first body portion  3110  as shown in their final state in the partially transparent examples of  FIG. 4A-C . In a finished inductor or “part,” each lead  3140   a  and  3140   b  may run along sides of the first body portion  3110  as shown in  FIG. 4B . Each lead  3140   a  and  3140   b  terminates with a contact portion  3130  bent underneath the first body portion  3110  as visible in  FIG. 1 . 
     As seen in  FIG. 1 , a shelf  3160 , step or indentation may be formed by the portion of lead  3140   a  that bends along an outer side of the inductor body  3110 . The shelf  3160  is formed adjacent where the lead meets the coil  3150 , which can also be seen in  FIG. 3 . The shelf  3160  may transition to a diameter less than the other portions of the lead  3140 . This shelf  3160  allows for the lead thickness exiting the body to be smaller to improve the ability to form the part. This shelf  3160  allows additional room for the coil inside the body. It is appreciated that this shelf  3160  is not required in all circumstances, and an inductor or coil or leads according to the invention could be formed without such a shelf. 
     As seen in  FIG. 1 , the configuration of coil  3150  may include a coil cutout  3170  adjacent an inner side of the coil where the shelf  3160  transitions to the curved portions Cl, C 2 . Coil cutout  3170  allows separation (space) between the lead and coil. 
       FIG. 2  shows that the body of the inductor may include a first cutout  3180  or groove in the first body portion  3110  to provide access for placing the lead contact portion  3130  under and against the bottom  3111  of the outer surface of the first body portion  3110 .  FIG. 3  shows that a second cutout  3190  or groove may also be provided in the first body portion  3110  to provide further access for placing the lead contact portion  3130  under and against the bottom  3111  of the outer surface of the first body portion  3110 . 
       FIGS. 4A-C  illustrate additional views of inductor  3100 .  FIG. 4A  illustrates a partially transparent view of the inductor  3100 , with the coil  3150  visible through the transparency.  FIG. 4B  illustrates a side view of inductor  3100  viewed from the lead  3140   a  edge.  FIG. 4C  illustrates a side view of inductor  3100  viewed from the non-lead edge. As illustrated coil  3150  may be shaped as an “S” or “Z,” depending on orientation. As used herein, the “S” or “Z” shaped may also comprise the mirror-image of such shapes when viewed from the top as shown in the Figures. For example, it is appreciated that the orientation of coil  3150  may be rotated  180  degrees to form the other of an “S” or “Z” configuration. 
       FIG. 5  depicts a method  3500  for making inductor  3100 . At step  3510 , the inductor is produced by stamping to produce features that become leads and a coil between the leads in a desired shape. The stamping may be performed on flat sheets of copper to produce features which make up electrical leads, one on one side of the part and one on the other side of the part, and a coil joining the two leads formed in an “S” shape. The stamped S-coil inductor is a simple and cost effective way to produce consistent inductors with inductance lower than lull. The stamped S-coil inductor is a simple and cost effective way to produce consistent inductors with a direct current resistance up to 80% lower than current high current, lower profile production methods in some instances. 
     As seen in  FIG. 6 , the sheets of copper may have leftover copper strips with progressive holes for alignment into manufacturing equipment, which are referred to as carrier strips or frame portions. The stamped copper sheets may be referred to as “leadframe.” 
     Continuing with the method shown in  FIG. 5 , at step  3520 , pressed powder, such as powdered iron, is poured into a die and pressed into a body about the coil with the leads extending therefrom. For example the body may be pressed to form a desired shape with a body similar to an IHLP inductor. The iron core and leadframe may now be referred to as a “part.” 
     At step  3530 , the part is cured in an oven. This curing process binds the core together. 
     After curing at step  3540 , the carrier strip is trimmed away from the leads on the leadframe. 
     The leads are folded around the body of the inductor to form the lead contact portions at step  3550 . 
     The stamped coil and leads could also be assembled using other known core materials known to the art. 
       FIGS. 6-7  collectively illustrate a leadframe  3600  formed at the stamping step (step  510 ) in method  3500 .  FIG. 6  illustrates an isometric view of leadframe  3600  and  FIG. 7  illustrates an overview of leadframe  3600 .  FIGS. 6-7  illustrate leadframe  3600  including a two coil  3150  structure as part of the leadframe. It is appreciated that any number of coils may be formed in the manufacturing process along a leadframe, and two coils are shown for ease of illustration and understanding only. 
     Leadframe  3600  includes a first frame portion  3620  and a second frame portion  3630  (also referred to as “carrier strips”) at the ends of the leads, and with the coil positioned centrally between the first frame portion  3620  and a second frame portion  3630 . The inductor assembly includes leads  3140 , and coil  3150 . Adjacent to lead  3140   a  is a shelf  3160 . The coil  3150  includes a coil cutout  3170 . First frame portion  3620  includes an alignment hole pattern  3610 . This pattern  3610  enables alignment as part of the manufacturing process. For example, during pressing. 
       FIGS. 8-11  illustrate a part  3800  of an inductor formed at the pressing step (step  3520 ) in the method discussed in  FIG. 5 .  FIG. 8  illustrates an isometric view of part  3800  formed at the pressing step depicting only the inner core  3115  surrounding the coil.  FIG. 9  illustrates an overview of part  3800  shown in  FIG. 8 .  FIG. 10  illustrates an isometric view of part  3800  formed at the pressing step depicting one of the inductors with body  3110 ,  3120  included and another where the body  3110 ,  3120  is shown in partially transparent visual allowing the inner core  3115  and coil  3150  to be viewed.  FIG. 11A  illustrates part  3800  in an overview of part  3800  with the outer body  3125  in partial transparency to show positioning of inner core  3115  and coil  3150 .  FIG. 11B  illustrates provides a partially transparent side view of part  3800  from  FIG. 10 . 
     Part  3800  includes leadframe  3600 , which includes first frame portion  3620  and second frame portion  3630  on opposite ends of the leads  3140   a  and  3140   b  and coil  3150 . Adjacent to lead  3140   a  is a shelf  3160 , indentation or step. On coil  3150  is a coil cutout  3170 . First frame portion  3620  includes an alignment hole pattern  3610 . This pattern  3610  enables alignment within the manufacturing process. 
     In an embodiment of the invention, part  3800  includes body  3125  pressed over the coil  3150  and a portion of leads  3140 , leaving exposed portions of the leads  3140   a  and  3140   b  and the first frame portion  3620  and second frame portion  3630 . Body  3125  may include first body portion  3110  and second body portion  3120  as described. Body  3125  may be formed from pressing a ferrite material around the coil  3150 . Body  3125  may be separate from an inner core  3115  or they may be formed together, such as a unitary part. The inner core can be formed in different ways: the material can be formed separately, typically from ferrite, and then laid on top of the coil and then the body can be pressed around it, or the inner core can be pressed around the coil separately, typically using some type of iron, and then the outer core can be pressed around the inner core using the same or different materials. The inner core could be used as the sole source of permeable material, or as the sole body of the device, without the outer core. When an inner core is used, the body  3125  may encase the inner core  3115 . In addition, a body  3125  could be formed as a unitary piece or combination with an inner core  3115 . In addition, the body may only be an inner core. 
       FIGS. 10 and 11A  and B show the inductor body  3125 , illustrating the body  3125  and inner core  3115 , with the body  3125  shown in transparency. The inner core  3115  may or may not be a separate part of the body  3125 , and is shown isolated for illustrative purposes in  FIGS. 8 and 9 . The inner core  3115  is generally cylindrical, and includes a channel shaped to receive the central portion  3151  of the coil  3150 . The curved portions C 1 , C 2  of the coil  3150  surround the inner core  3115 , as shown ion  FIG. 10 . When the first body portion  3110  and second body portion  3120  are brought together, they may form or otherwise contain the inner core  3115 . 
     In one embodiment, an inductor may have multiple stacked coils, as shown in the examples of  FIGS. 12-14 .  FIG. 12  illustrates an isometric view of inductor  3100  with two coils. As depicted in  FIG. 12  where coils are attached to a leadframe, a second coil  3150   b  is aligned and adhered to, such as laminated to, a first coil  3150   a.  In adhering the coils  3150   a,    3150   b  together, solder may be used. This solder in addition to adhering and maintaining alignment provides an electrical connection between the first coil  3150   a  and the second coil  3150   b.  The multi-coil structure of  FIG. 12  may be formed by aligning and attaching coils held by two leadframes, or by aligning and adhering a second coil that has already been separated by a leadframe and/or leads to a first coil. Once aligned and adhered, the leadframe for the second coil  3150   b  may be removed for subsequent processing steps exposing a singular lead  3140 . 
       FIG. 13  illustrates a top view of the multi-coil, multi-layered embodiment of  FIG. 12 . From this view, only the second coil  3150   b  may be seen. The leadframe associated with the second coil  3150   b  has been removed exposing the lead  3140   a  from the first coil  3150   a  leadframe. If formed by aligning two leadframes, a boundary  3145   b  or edge may be formed where the leadframe of the second coil  3150   b  is removed. The coils may also be separated from each other within the body using insulation between each coil layer. This insulation may provide improved performance of the inductor in certain situations. The insulation may comprise Kapton™, Nylon™, or Teflon™, or other insulative materials as are known in the art. The coils may be connected on the ends using a method such as welding and/or soldering. 
       FIG. 14  illustrates an inductor  3100  with a plurality of coils, showing a three-coil design. As depicted a first coil  3150   a  is included in the leadframe and a second coil  3150   b  is aligned and adhered to a top of the first coil  3150   a  and a third coil  3150   c  is aligned and adhered to a bottom of the first coil  3150   a.  In adhering the coils  3150   a,    3150   b  and  3150   a,    3150   c,  a solder  3232  may be used as shown in  FIG. 23 . This solder in addition to adhering and maintaining alignment provides an electrical connection between the first coil  3150   a  and the second coil  3150   b.  Once aligned and adhered the leadframe for the second coil  3150   b  and the third coil  3150   c  may each be removed for subsequent processing steps exposing a singular lead  3140 . 
     The leadframe associated with the second coil  3150   b  has been removed exposing the lead  3140   a  from the first coil  3150   a  leadframe. A boundary  3145   b  is formed from the removal of the leadframe of the second coil  3150   b.  The leadframe associated with the third coil  3150   c  has been removed exposing the lead  3140   a  from the first coil  3150   a  leadframe. A boundary  3145   c  is formed from the removal of the leadframe of the third coil  3150   c.  The first coil  3150   a,  second coil  3150   b  and third coil  3150   c  may or may not be separated by insulation  3231  as shown in  FIG. 23 . 
       FIG. 15  illustrates a formation of the coil with a reduced leadframe having only one carrier strip  3621 . In  FIG. 15 , a stamped “S” shaped coil  3150  may have the same elements as described in  FIG. 1 . The “S” shaped coil  3150  includes a first lead  3140   a  connected to the carrier strip  3621 , and a second lead  3140   b  extending from an opposite side of the coil  3150 . 
       FIG. 16  illustrates an alternate shape for an inductor coil. In  FIG. 16 , an “N” shaped coil  3159  (where the “N” is standing up relative to the length of the carrier strip  3561 ), is provided. The “N” shaped coil  3159  includes a first portion N 1  that connects with a second lead  3140   b,  and a second portion Ni that connects to a first lead  3140   a  that connects to the carrier strip  3621 . The two portions N 1  and N 2  are connected by a central portion N 3  of the coil  3159 . The two portions N 1  and N 2  of  FIG. 16  are generally straight compared to the curved portions C 1  and C 2  of  FIG. 1 . The outer corners of the portions N 1  and N 2 , where the portions bend of meet the leads  3140   a,    3140   b,  curved away from the central portion N 3  of the coil. 
       FIG. 17  illustrates a depiction of an assembled inductor  3100  according to the present invention. Inductor  3100  includes a first body  3110  and second body  3120 . Also shown is lead  3140 , including a step adjacent where the lead exits the body. 
       FIG. 18A  and B illustrate an assembled inductor  3100  according to the present invention. 
       FIG. 19  illustrates an inductor shown with the second body  3120  in partial transparency, and cut-away from the top. Coil  3150  is shown connecting leads  3140   a  and  3140   b.  Coil  3150  includes regions Cl, C 2  with a cross-member  3151 . 
       FIG. 20-21  illustrate coil  3150  from an assembled inductor  3100  (e.g., with the leads bent) with other parts of the inductor  3100  removed.  FIG. 20  depicts an isometric view of coil  3150  from above and  FIG. 21  depicts an isometric view of coil  3150  from below. Coil  3150  is shown connecting leads  3140 . Coil  3150  includes curved or arced regions or portions Cl and C 2  with a cross-member or central portion  3151 . 
       FIG. 22A  and B illustrate, in transparency, embodiments of a first body  3110  ( FIG. 22B ) and a second body  3120  ( FIG. 22A ) from an assembled inductor  3100  with other parts of the inductor  3100  removed. First body  3110  and second body  3120  includes an inner core recess  3221  and a channel recess  3222  for receiving or accommodating a separate inner core and a channel for the coil as described above. First body  3110  and second body  3120  could also form the inner core and include a channel for the coil as described above. In one example, the top of first body  3110  meets the bottom of second body  3120  to create the inner core  3221  recess and the channel recess  3222 . 
       FIG. 24  shows an isometric view of another embodiment of a coil according to the invention. An illustrative coil  190  is shown, including leads  130 a,  130   b  extending from opposite ends of the coil  190 . The coil  190  may be formed from a conductor  100 , having a width  150  and a height (or thickness)  160 . The formed coil and leads  130 a,  130   b  may be referred to as a “leadframe.” The conductor  100  may be formed from a metal strip. Acceptable metals used for forming the coil may be copper, copper, aluminum, platinum, or other metals for use as inductor coils as are known in the art. Acceptable metals for the leads may be copper, aluminum, platinum, or other metals for use as inductor leads as are known in the art. 
     In a preferred example, the width  150  of the conductor  100  is greater than the height  160 , as shown in  FIG. 24 . In one aspect of the invention, the width of the coil  190  is associated with the width of the conductor  100 . In another orientation of the coil, the height of the conductor may be greater than the width, and the height of the coil may be associated with the height of the conductor. The conductor  100  may be a wire, a metal strip or a metal form stamped from a sheet of metal, or another conductive material as is known in the art. The conductive material preferably has a flat surface and flat edges. However, it is appreciated that the conductive material, either before or after formation into a coil of the invention, may have a rounded, oblong or oval surface, edges or shape. Thus, the coil and/or leads may have a rounded or curved surface or edges. 
     In a preferred embodiment, the coil  190  may comprise a first curved portion  110 , and a second curved portion  120 . The curved portions  110  and  120  preferably curve away from and/or around a central portion  140  of the coil  190 , and thus may be considered “outwardly” curving relative to the central portion  140 . Each curved portion  110  and  120  of the coil  190  may extend along a part of the circumference of a circular or arched path curving around the central portion  140  of the coil  190 . 
     Referring to  FIG. 25 , the first curved portion  110  may have a first end  180   a  connecting with the first lead  130   a,  and a second end  115  that curves into the central portion  140 . The second curved portion  120  may have a first end  180   b  connecting with the second lead  130   b,  and a second end  125  that curves into the central portion  140 . The central portion  140  preferably crosses the center of the coil, and runs essentially diagonally or at a sloped angle from the second end  115  of the first curved portion  110  to the second end  125  of the second curved portion  120 . 
     As shown in the view of  FIG. 25 , the leads  130   a,    130   b  may be offset from a center line  131  running along the length of the coil, prior to the leads being bent or further shaped. In another embodiment, the leads  130   a,    130   b  may be aligned along a center line running along a length of the coil. 
     An exemplary serpentine coil having an “S” shape, when viewed from the top as shown in the Figures, may be seen in  FIGS. 24, 25, 27, 29, 31, and 32 . Alternatively, the coil may be formed in any other appropriate shape, such as a “Z” or an “N.” The length of the conductor may vary during production, as the conductor&#39;s length is subject to the number of inductors to be made, the number of coils formed from a length of conductor, or the raw materials used to produce the conductor. The coil  190  may have a vertical height  170  running from a top of the coil (when oriented as in  FIGS. 25, 27 and 29 ) to the bottom of the coil. The vertical height  170  contributes to the space taken up by the coil when placed in an inductor core or body. The width  150  and/or height  160  of the conductor  100  may be less than the vertical height  170  of the formed coil. The coil  190  may be shaped in a unique configuration that provides for increased efficiency and performance for an inductor in a small volume. In a preferred embodiment, the shape may be an “S” shape when viewed from the side of the coil  190 , as shown for example in the orientation of  FIG. 25 . The shape of the coil  190  is designed to optimize the path length of the conductor  100  to fit the space available within the core  260  of the inductor  200  while minimizing resistance and maximizing inductance. The shape may be designed to increase the ratio of the space used compared to the space available in the inductor body  200 . In an embodiment, an inductor according to the invention may achieve and inductance of 0.135 μH at 0.21 mΩ. 
     In one embodiment the conductor may be square in its cross-section, as opposed to flat where the width would be greater than its height. The conductor may also take any shape in its cross-section such as rectangular, triangular, prism, circular, ovular, or the like. In any example, embodiment, or discussion of the conductor as disused herein, the conductor cross-section may take any of the shapes as discussed herein. 
       FIGS. 26-30  show an assembled inductor  200  with a core  260  formed around the coil  190 . The inductor  200  may be oriented vertically, as illustrated in the Figures, where the core or body  260  is oriented in an upstanding manner, with leads  135   a,    135   b  at the bottom for mounting to, for example, a circuit board. 
       FIG. 26  shows a view from a front side  263   a  of an inductor  200  with an illustrative core  260 , with the inductor leads  130   a,    130   b  formed around a lower surface  261   b  of the core  260 . Portions of the leads  130   a,    130   b  may curve at points  180   c,    180   d,  respectively, upon exiting the core. The leads  130   a,    130   b  and coil  190  may be formed as a unitary piece, without a weld. The core may be a square, rectangular, or another other shape that encompasses the dimensions of the core  260 . The core  260  may have a height  220  from the top  261   a  to the bottom  261   b,  which, in one embodiment, is greater than the vertical height  170  of the coil  190 . 
       FIG. 27  shows the front side view of an inductor  200 , where the core  260  is partially transparent to view the interior. The leads  130   a,    130   b  terminate at lead ends  135   a,    135   b,  respectively, after wrapping around the core  260  at points  210   a,    210   b  respectively for a distance  230  from their exit points  180   c,    180   d.  Leads  130   a,    130   b  may preferably curve around the bottom  261   b  of the core  260  at points  210   a,    210   b,  respectively, thereby having the leads  130   a.    130   b  “hug” or rest directly against the core  260  to create surface mount terminals along portions of the bottom surface  261   b  where the leads  135   a  and  135   b  extend. Each lead  130   a,    130   b  may run along a portion of the bottom surface  261   b  of the core  260 . 
     In an embodiment, magnetic material, such as iron, may be poured into a die and pressed into a core  260  that will encompass the coil  190 . In other embodiments other materials beside iron may be used to form the core  260  or core portions. For example, a magnetic molding material may be used for the core  260 , comprised of a powdered iron, a filler, a resin, and a lubricant, such as described in U.S. Pat. No. 6,198,375 (“Inductor coil structure”) and U.S. Pat. No. 6,204,744 (“High current, low profile inductor”). 
     In other embodiments, a core may be formed as multiple pieces formed together. For example, there may be a two-piece core, with a first portion and a second portion of the core; both portions may be formed in similar fashion and of the same materials, or the first portion and second portion may be formed using different processes and from distinct materials. The shape of the core may be similar to an IHLP™ inductor known in the art and may by of an appropriate size to encompass a coil  190 . The core and leadframe may be combined after the coil has been formed. 
       FIGS. 28 and 29  show isometric views of the inductor as shown in  FIGS. 26 and 27 , respectively. 
       FIG. 28  shows the exit and curvature point  180   c  where the lead  130   a  exits the core  260  approximately at the mid-point of the first side  262   a.    
     In the orientation as shown in  FIG. 29 , the coil  190  and leads  130   a,    130   b  are visible through the transparent core  260  just for explanation purposes. In  FIG. 29  the width  150  of the leads  130   a,    130   b  extend between the front side  263   a  and a back side  263   b  of the core  260 . On the second side  262   b  of the core  260 , the lead  130   b  exits the core  260  at point  180   d.  In one embodiment, the width  150  of the leads  130   a,    130   b  may be less than that of the depth  250  of the core  260  from front  263   a  to back  263 b. In another embodiment, the width  150  of the leads  130   a,    130   b  may be the same as that of the depth  250  of the core  260  from front  263   a  to back  263   b.  The core  260  may also include a back side  263   b,  top side  261   a,  and a bottom  261   b.    
     A unique feature of the present invention is the positioning of the coil  190  and leads  130   a,    130   b  with respect to the core  260 . As shown in the orientation of  FIG. 29 , the coil  190  and leads  130   a,    130   b  have a width  150  that runs along at least a portion of the depth  250  of the core  260 . 
       FIG. 30  shows the bottom view of an illustrative inductor  200 . The lead ends  135   a,    135   b,  are shown wrapping around portions of the sides and portions of the bottom surface  261   b  of the core  260 . These may form the electrical contact points for the inductor  200 , such as surface mount leads. The bottom  261   b  is opposite to the top  261   a  of the core  260 . The lead ends  135   a,    135   b  may have a width  150  that may be less than the depth  250  of the core  260 . In alternative embodiments the leads  130   a,    130   b  may have a width similar to or the same as the depth  250  of the core  260 . 
       FIG. 31  shows an isometric view of example coil production with multiple coils  190  formed from a conductor  100 . The coils  190  may be formed in the same shape and size for one coil production or may be formed in varying shapes and sizes. The lead portions  130  may be aligned along a generally straight path or line extending along the length of the conductor. Alternatively, the lead portions  130  may be in different planes (offset) relative to one another between each coil  190 . In  FIG. 24  there is a single illustrative coil  190 , but it may appreciated that there may by multiple coils formed from a single piece of material as shown in the example of  FIG. 31 . The conductor  100  may be composed of a metal such as copper or any other suitable material appropriate to make an inductor coil. The conductor  100  may be plated, such as with nickel and/or tin. 
       FIG. 32  shows an isometric view of an example parts production with coils  190  and parts  270  formed. In  FIG. 32  a core  260  has been combined with a coil  190  that was previously formed with the conductor  100  to create parts  270 . Parts  270  comprise an inductor  200  without the lead portions  130  separated or bent around the body of the core  260 . The lead portion  130  of conductor  100  between the parts  270  may be separated to form the leads  130   a,    130   b  each with lead ends  135   a,    135   b,  respectively. 
       FIG. 33  describes an example process of manufacturing an inductor. In one embodiment, at step  1010  a conductor, such as rectangular nickel (Ni) and tin (Sn) plated un-insulated copper wire, may be bent to form a plurality of “S” coils. At step  1020  cores made of iron may be created separately or may be created during the same process, and may be attached or pressed on to each coil. At step  1030  the parts may be cured in an oven to bind the coils and the cores together. Afterwards, the parts may be separated and the lead portions of the leadframe may be folded around each core to produce the inductor. The coils and leads of the present invention are preferably formed as a complete unitary piece; that is, no interruptions or breaks are formed in the coil from one lead to the next coil prior to the lead portions being separated/cut. 
     In another embodiment, an inductor may be made from a folded conductor, such as a metal strip, a wire or stamped piece of conductive metal. The metal strip, a wire or stamped piece of conductive metal may preferably be flat. A conductor may be folded and shaped to form the coil and leads.  FIG. 34A  shows an isometric view of an example of folded conductor  1101  to be used in the making of an inductor according to the invention.  FIG. 34B  shows the formation of a folded conductor  1101  from a front perspective of an illustrative conductor  1102 . The folded conductor  1101  may be formed as a conductor that is folded over itself at the middle  1103  of the width of the conductor, in a general U-shape when viewed in cross-section. The folded conductor  1101  may be folded along its width such that the fold creates two sides or layers of equal width  1105   a  and  1105   b,  joined by a curved or bent portion  1103 . In some embodiments the two layers may not be equal. The conductor may be folded to create more than two layers.  FIG. 34C  shows a folded conductor  1101  from a front perspective with insulation between the two folded layers. The insulation may be in each layer of folded material, or the insulation may be in selected layers. 
     In the folded conductor arrangement, several options are contemplated. A conductor may be folded to form the folded conductor  1101 , and insulation may be added between the layers after the folding process. In another embodiment, the conductor may have a surface coated with insulation prior to folding. When folded, the folded conductor  1101  would bring the insulated surfaces of the layers into contact. In another embodiment, the conductor is folded to form a folded conductor  1101 , and no insulation is provided between the layers. In another embodiment, the conductor may be folded so as to bring the layers into direct contact. In that case, the layers may be pressed into each other. 
     In one example of forming the conductor  1102 , the conductor  1102  may have two edges  1105   a  and  1105   b  that are moved downward relative to the middle  1103  of the width  1104   a  of the conductor  1102  to form the folded conductor  1101 . Note that the width  1104   b  of the folded conductor  1101  is approximately half that of the width  1104   a  of the conductor  1102 . In one aspect, the folded conductor may have an insulating material sandwiched in between the two layers  1105   a  and  1105   b.  In a scenario where there is more than one fold, the insulating material may be present in between each layer so as to insulate the folded layers. The material may be made out of any material that has insulating properties (i.e., non-conductive) that one of ordinary skill in the art may use, such as but not limited to, ceramic, glass, gas, plastic, rubber, etc. 
       FIG. 35  shows an example of an inductor coil  1202  made from a folded conductor in a serpentine shape with lead portions  1201  and  1203 , similar to the arrangement of  FIG. 24 , but with the coil made from the folded conductor  1101  arrangement. The coil  1202  may take the shape and be formed similarly to the arrangements shown and described with respect to  FIGS. 24-33  as to the serpentine shape.  FIG. 35  shows an S-shaped coil, as viewed from the top. Alternatively, the coil  1202  may take a non “S” shape and be formed according to other shapes as discussed herein, such as an “N” a “Z” or some other form that generates an inductance. 
     In an alternative embodiment,  FIG. 36  also shows an example of an inductor coil  1202 , similar to the arrangement of  FIG. 35 , but the lead portions  1201  and  1203  extending from the coil are made from folded conductor  1101  that has been split or cut or separated along a general mid-point  1301  of the conductor  1101  to form a slit or seam. In  FIG. 36 , only the leads  1201  and  1203  have been separated into two halves  1303  and  1304  and the coil  1202  remains as a unitary two-sided, two-layer, two-walled or two-sided structure. 
       FIG. 37  shows an isometric view of an illustrative inductor coil  1202  where the lead portions  1201  and  1203  have been formed into surface mount leads from a folded conductor  1101 . The coil  1202  may have a central portion  1240 . These leads are formed by splitting and/or splaying and flattening and/or unfolding lead portions  1201  and  1203  at opposite ends of the folded conductor  1101 . For example, lead  1203  is unfolded from the folded conductor  1101  to a conductor  1102  creating a generally triangular side surface portion  1404 . The lead  1203  may be further formed by bending the side surface portion  1404  at an edge  1401  creating a flat surface  1406   b,  such as for surface mounting, partially underneath and along part of a bottom surface of the inductor core body  1501 . The side surface portion  1404  may begin at the end of the coil  1405  and may also have folded edges  1402   a  and  1402   b  due to the overlap of the folded conductor  1101  when it is formed to create the side surface portion  1404 . The same process and formation may occur with the other lead  1201  on the opposite side such that the two leads  1201  and  1203  have a similar structure. 
       FIG. 38  shows an isometric view of an illustrative inductor  1500 , with the coil  1202  of  FIG. 37  encased in a core  1501 . The core  1501  is shown in partial transparency so that the interior of the core  1501  may be viewed. The core  1501  may take the shape and be formed similarly to the shapes and methods described herein with reference to the core  260  shown in  FIGS. 24-33 . The lead  1203  may exit the core  1501  and wrap around the bottom  1502  of the core  1501  thereby creating electrical contact point, such as surface mount leads, for the inductor  1500 . The same process and formation may occur with the other lead  1201  on the opposite side such that the two leads  1201  and  1203  have a mirrored structure relative to the coil  1202 . The leads  1201  and  1203  may exit the core  1501  in the form of the flat folded conductor  1101  and then formed as discussed above. 
       FIG. 39  shows a top view of the illustrative inductor  1500  of  FIG. 38 , with a partially transparent core  1501  to show the coil  1202 , leads  1201 ,  1203  and mounting surfaces  1406   a,    1406   b  in the interior. 
       FIG. 40  shows another embodiment of an inductor coil  1202  formed from a folded conductor where the leads  1201  and  1203  are made from the partially separated folded conductor as shown in, for example,  FIG. 36 . The lead  1203  is separated into portions  1303  and  1304  and formed and shaped in a manner similar or the same to the reformation of lead  1203  as described with relation to  FIG. 37 .  FIGS. 41  and  FIG. 42  show a core  1501  in partial transparency positioned around the coil  1202  and leads, with leads  1303  and  1304  being separated at split  1301  into portions  1303  and  1304 . 
       FIG. 43  shows an isometric view of another embodiment of a coil  1202  having cut and folded leads. The coil  1202  is formed from a folded conductor having split lead portions. In this embodiment, one side of the split portions of the leads are cut, unfolded and bent to conform to the surface of the core  1501 , wherein one side of each of the lead portions remains as a surface mount lead. As can be seen in  FIGS. 44 and 45 , leads  1201  and  1203  are cut and folded in such a way to create contact points, such as surface mount leads, on the top side surface of an inductor. For example, mounting surface  2001  may be the contact surface of lead  1203 . Lead  1203  also may have a flat side surface  2003  adjacent to and running along the side of the core  1501 . The lead  1203  exiting the coil  1202  is bent at portion  2004 . The lead  1203  is further bent at portion  2002 .  FIG. 44  is an isometric view showing a partially transparent core  1501  for visualization purposes around the coil  1202  shown in  FIG. 43 .  FIG. 45  is the partially transparent top perspective of  FIG. 44  showing the inductor  2100  with the cut and folded leads. Lead  1201  is formed in a similar manner. 
       FIGS. 46A-D  show an illustrative process in which the leads may be cut and folded to form the arrangement shown in  FIGS. 43, 44 and 45 .  FIG. 46A  shows step  2301 , where leads  1201  and  1203  can be seen extending from the core  1501 . The leads  1201  and  1203  are made of folded conductor that can be seen as a folded U-shape similar to  FIG. 34A and 34B  except that the height/width of the two layers are not equal making it easier to grab the lead and un-fold it. A cut may be made at along cut-line  2302 , and similarly along a cut-line in lead  1201 .  FIG. 46B  shows step  2303 , where lead  1203  is un-folded in direction  2304  to create an L-shape extending from the core  1501 , with the same process applied to lead  1201 .  FIG. 46C  shows step  2305 , where leads  1201  and  1203  are flattened or pressed against the side surfaces of the core  1501  and bent at portion  2004  along motion line  2306 .  FIG. 46D  shows step  2307 , where the leads  1201  and  1203  are bent again to conform to the top surface portion of the core  1501  in a folding motion  2308  thereby creating contact or surface mount portions as shown in  FIGS. 44, 45 and 46A -D. 
       FIGS. 47A-D  shows an illustrative process of forming a leadframe of an inductor made by stamping and folding according to one embodiment.  FIG. 47A  shows a first step  2401  where a metal frame  2402  has been formed by stamping a piece of metal, with apertures at the top  2404   a  and bottom  2404   b  that may be used to secure the metal in place during the formation process. The metal may be any electrically conductive metal or combination of metals. For example, and not by way of limitation, the metal may be a Ni and Sn plated copper sheet. At the frame&#39;s  2402  inner topside a lead portion  2406   a  extends downward leading to a coil connection point  2408   a,  a piece of conductor  2410 , and another coil connection point  2408   b  and another lead  2406   b.  Slots are formed adjacent the coil connection points  2408   a,    2408   b.  A gap  2412   a  is formed where the stamp has separated the frame  2402  and the bottom lead  2406   b.    
       FIG. 47B  shows step  2403  shows a central portion of the flat metal conductor  2410  being folded perpendicular to the plane of the frame  2402 .  FIG. 47C  shows step  2405  with coil  2410  being formed, such as by bending, in an “S”-shape from the folded conductor  2410  causing the pervious gap  2412   a  to expand to the size of gap  2412   b.  Alternatively, the coil  2410  may be formed in any of the shapes as described herein.  FIG. 47D  shows an embodiment with a large sheet of metal where multiple frames have been stamped at the same time as shown at  2407 . 
       FIG. 48  shows an example inductor using the stamped formation process from  FIGS. 47A-47D . In step  2501  the coil  2410  (not visible) has been encased in a core  2510  and the lead  2406   b  has been folded in a motion  2512  bending at  2502  and  2506  to wrap around a surface of the core  2510  creating a surface portion  2504  and a contact point  2508  or surface mount terminal for the lead  2406   b.  A similar process and formation is performed with respect to lead  2406   a.    
       FIG. 49A-D  show an embodiment for forming the splayed folded conductor discussed above in connection with various embodiments. The splayed conductor has an H-shape, with slots at opposite ends.  FIG. 49A  shows step  2601  with a flat piece of conductor  2602 .  FIG. 49B  shows step  2603 , where the conductor  2602  may be splayed, separated, cut or stamped to form an elongated H-shape having top extensions  2604   a  and bottom extensions  2604 b, with slots in between.  FIG. 49C  shows step  2605 , where the conductor  2602  is folded along portion  2606  such that the top extension  2604   a  and bottom extension  2604   b  are parallel with each other and brought into proximity.  FIG. 49D  shows step  2607 , where the splayed folded conductor can be seen from a front perspective with the fold at portion  2606  and the extensions  2604   a  and  2604   b  parallel with each, and having a central U-shape. 
       FIG. 50A-D  show an example process for forming an inductor having a splayed folded conductor of  FIG. 49  to create a coil, leads and/or inductor such as that shown in  FIGS. 30, 31, and 32 .  FIG. 50A  show step  2701 , where the core  2702  is formed around the coil (internal to the core) while the leads extending outwardly from opposite sides of the core.  FIG. 50B  shows step  2703 , where the leads  2604   a  and  2604   b  are bent away from each other in a direction designated as  2608 .  FIG. 50C  shows step  2705 , where the lead extensions  2604   a  and  2604   b  are bent in a downward motion  2610  over themselves, so that a folded portion partially lays over a non-folded portion.  FIG. 50D  show step  2707 , where the lead extensions  2604   a  and  2604   b  are bent underneath the core  2702  in a direction indicated by arrows  2612 . This can be seen from alternative perspectives in  FIG. 50E  and  FIG. 50F . 
       FIGS. 51A-H  show an example process of an alternative embodiment for forming an inductor coil and an inductor with lead ends that are formed separately and then joined to the coil with lead portions extending from the inductor core body.  FIG. 51A  show step  2801 , where a coil  190 , such as that shown in  FIG. 24 , made from a conductor having lead portions  130   a  and  130   b,  is formed.  FIG. 51B  shows step  2803 , where a core  260  is formed around the coil  190 . The lead portions  130   a  and  130 b extend outwardly from the core  260 .  FIG. 51C  shows step  2805 , where the lead portions  130   a  and  130   b  are clipped, trimmed, or cut so that they extend a distance from the core  260 . The distance may be associated with a thickness, such as the thickness of a flat lead conductor shown in  FIG. 51D . The flat lead conductor of  FIG. 51D  is introduced/created at step  2807  where one or more flat lead conductors are formed, each having a base  2802  and extensions  2804   a  and  2804   b  (a.k.a.  2804  collectively), with a slot between the extensions  2804   a  and  2804   b,  formed in a general U-shape. The extensions  2804  of each flat lead conductor extensions will surround each of the lead portions  130   a  and  130   b.    FIG. 51E  shows step  2809 , where the U-shaped flat lead conductors are connected to the lead portions  130   a  and  130   b  such that the slot in between the extensions  2804  is filled by the trimmed lead portions  130   a  and  130   b;  the flat lead conductors may be attached by soldering or the like. Also at step  2809 , the base  2802  extends past the edge surface of the core  260  at the bottom surface of the core  260 .  FIG. 51F  and  FIG. 51G  show steps  2811  and  2813 , respectively, where the base  2802  is bent at a corner  2806  in a direction indicated by arrow  2808  such that it will wrap around the bottom of the core  260  and act as a contact point or surface mount terminal.  FIG. 51H  shows step  2815 , where the inductor is shown with the core  260  in partial transparency to illustrate the base  2802  wrapping around the bottom surface of the core  260 , and to show the coil  190  positioned inside the core  260 . 
     An inductor according to any of the embodiments discussed herein may be utilized in electronics applications, such as DC/DC converters, to achieve one or more of the following: low direct current resistance; tight tolerances on inductance and or direct current resistance; inductance below 1 uH; low profiles and high current; efficiency in circuits and/or in situations where similar products cannot meet electric current requirements. In particular, an inductor may be useful in DC/DC converters operating at 1 Mhz and above. 
     The present invention provides for an inductor provided with a high current serpentine coil, such as an “S” shaped coil, with low direct current resistance (IHVR). The design simplifies manufacturing by eliminating a welding process. The design reduces direct current resistance by eliminating a high resistance weld between the coil and the leads. This allows for inductors with inductance ratings below 1 uH to be produced consistently. The “S” shape for the coil optimizes inductance and resistance values compared to a similar stamped coil configuration and other non-coil configurations. 
     The formed serpentine coil inductor, such as a coil in the S-shape described herein, provides a simple and cost-effective way to produce consistent inductors and to produce inductors with direct current resistance up to  80 % lower than comparable known inductors such as IHLP inductors. 
     It will be appreciated that the foregoing is presented by way of illustration only and not by way of any limitation. It is contemplated that various alternatives and modifications may be made to the described embodiments without departing from the spirit and scope of the invention. Having thus described the present invention in detail, it is to be appreciated and will be apparent to those skilled in the art that many physical changes, only a few of which are exemplified in the detailed description of the invention, could be made without altering the inventive concepts and principles embodied therein. It is also to be appreciated that numerous embodiments incorporating only part of the preferred embodiment are possible which do not alter, with respect to those parts, the inventive concepts and principles embodied therein. The present embodiment and optional configurations are therefore to be considered in all respects as exemplary and/or illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all alternate embodiments and changes to this embodiment which come within the meaning and range of equivalency of said claims are therefore to be embraced therein.