Patent Publication Number: US-9842682-B2

Title: Modular integrated multi-phase, non-coupled winding power inductor and methods of manufacture

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation application of International Application No. PCT/CN2015/098193. 
    
    
     BACKGROUND OF THE INVENTION 
     The field of the invention relates generally to electromagnetic inductor components, and more particularly to an integrated, multi-phase power inductor component having a configurable number of non-magnetically coupled coil windings for circuit board applications. 
     Power inductors are used in power supply management applications and power management circuitry on circuit boards for powering a host of electronic devices, including but not necessarily limited to hand held electronic devices. Power inductors are designed to induce magnetic fields via current flowing through one or more conductive windings, and store energy via the generation of magnetic fields in magnetic cores associated with the windings. Power inductors also return the stored energy to the associated electrical circuit by inducing current flow through the windings. Power inductors may, for example, provide regulated power from rapidly switching power supplies in an electronic device. Power inductors may also be utilized in electronic power converter circuitry. 
     Power inductors are known that include multiple windings integrated in a common core structure. Existing power inductors of this type however, are problematic in some aspects and improvements are desired. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Non-limiting and non-exhaustive embodiments are described with reference to the following Figures, wherein like reference numerals refer to like parts throughout the various drawings unless otherwise specified. 
         FIG. 1  is a top perspective view of a first exemplary embodiment of an electromagnetic surface mount, power inductor component assembly. 
         FIG. 2  is an exploded view of the power inductor component assembly shown in  FIG. 1 . 
         FIG. 3  is an exploded view of a scalable power inductor component assembly including the inductor component assembly shown in  FIG. 1 . 
         FIG. 4  is an exploded view of a scalable power inductor component assembly including the inductor component assembly shown in  FIG. 3 . 
         FIG. 5  is a top perspective view of a second exemplary embodiment of an electromagnetic surface mount, power inductor component assembly. 
         FIG. 6  is an exploded view of the power inductor component assembly shown in  FIG. 5 . 
         FIG. 7  is an exploded view of a scalable power inductor component assembly including the inductor component assembly shown in  FIG. 5 . 
         FIG. 8  is an exploded view of a scalable power inductor component assembly including the inductor component assembly shown in  FIG. 7 . 
         FIG. 9  is a top perspective view of a third exemplary embodiment of an electromagnetic surface mount, power inductor component assembly. 
         FIG. 10  is an exploded view of the power inductor component assembly shown in  FIG. 9 . 
         FIG. 11  is a lateral side elevational view of the power inductor component assembly shown in  FIG. 9 . 
         FIG. 12  is a longitudinal side elevational view of the power inductor component assembly shown in  FIG. 9 . 
         FIG. 13  is a bottom view of the power inductor component assembly shown in  FIG. 9 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     As mentioned above, electromagnetic power inductors are known that include, for example, multiple windings integrated in a common core structure. Such inductor components are typically beneficial to provide multi-phase power regulation at a reduced cost relative to discrete inductor components including separate magnetic cores and windings for each respective phase of electrical power. As one example, a two phase power system can be regulated with an integrated power inductor component including two windings. One winding is connected to the first power phase of electrical circuitry on a circuit board, and the other winding is connected to the second power phase of electrical circuitry on a circuit board. The integrated windings on a common core structure typically saves valuable space on the circuit board relative to providing one discrete inductor component including its own magnetic core for each phase. Such space savings can contribute to a reduction in size of the circuit board and also the electronic device including the circuit board. 
     Known integrated multi-phase power inductor component constructions are limited, however, in certain aspects and are therefore undesirable for application in certain types of electrical power systems. As such, existing power inductor constructions have yet to fully meet the needs of the marketplace in certain aspects. 
     For example, in multi-phase power supply applications, inductance unbalance issues between different phases connected to each winding can be problematic, and thus achieving balanced performance can be particularly difficult for smaller components in higher power, higher current applications that modern day electrical devices demand. 
     Also, multi-phase electrical power systems are in widespread use including different numbers of phases of electrical power. As a result, customized components tend to be the norm to meet the needs of power systems having different numbers of phases. The customized nature of such components tends to increase the cost of manufacture and assembly for the components. In particular, the core constructions tend be different for inductor components having one, two, three or more windings. It would be desirable to provide a set of power inductors that can be manufactured from a reduced number of parts, and in particular from modular magnetic core pieces that can be assembled to easily configure inductors having different numbers of windings at relatively low cost. 
     Saturation current (Isat) performance tends to be limited by the core construction in known integrated multi-phase power inductor components. Improvement is desired for state of the art electrical power systems for higher powered electronic devices. 
     The form factor of known integrated multi-phase power inductor components, including the “footprint” (understood by those in the art as a reference to an area that the component occupies on a plane of the circuit board) and profile (understood by those in the art as a reference to the overall component height measured perpendicular to the plane of the circuit board) can effectively limit the ability of the component to perform in higher current, higher power system applications. Balancing the power demands of higher power circuitry with a desire for ever-smaller components is a challenge. 
     Finally, alternating current resistance (ACR) caused by fringing effect of integrated multi-phase power inductor component in use can be undesirably high in known component constructions. 
     Exemplary embodiments of integrated electromagnetic multi-phase inductor component assemblies for power supply circuitry on a circuit board (i.e., power inductors) are described hereinbelow that overcome at least the disadvantages described above. The exemplary inductor component assemblies achieve this at least in part via modular core pieces that can be selectively assembled with a set of conductive windings in any number desired while simplifying assembly of the component and lowering manufacturing cost. Fringing flux from conventionally employed discrete air gaps in the core structure are avoided and ACR caused by fringing effect is accordingly reduced while providing reliably balanced operation of the windings in use for each power phase. Higher power capability is provided with three dimensional conductive windings formed from planar conductive material and core structure that has a relatively small footprint in combination with a relatively taller profile to accommodate higher power, higher current applications. 
       FIG. 1-4  illustrate various views of a first exemplary embodiment of a surface mount, power inductor component assembly  100 .  FIG. 1  shows the power inductor component assembly  100  in perspective view.  FIGS. 2 through 4  are exploded view of the power inductor component assembly  100  and assemblies including the component assembly  100  that are configured to include different numbers of windings for electrical power systems having different numbers of phases. 
     The power inductor component assembly  100  generally includes, as shown in  FIG. 1 , a magnetic core  102  with integrated conductive windings  104  and  106  respectively arranged in the magnetic core  102 , and a circuit board  110 . 
     The circuit board  110  is configured with multi-phase power supply circuitry, sometimes referred to as line side circuitry  116 , including conductive traces  112 ,  114  provided on the plane of the circuit board in a known manner. In the example shown in  FIG. 1 , the line side circuitry  116  provides two phase electrical power, and in contemplated embodiments the first conductive trace  112  corresponds to a first phase of the multi-phase power supply circuitry and the second conductive trace  114  corresponds to the second phase of the multi-phase power supply circuitry. In turn, the first conductive winding  104  is connected to the first conductive trace  112  and the first phase and the second conductive winding  106  is connected to the second conductive trace  114  and the second phase of the multi-phase power supply circuitry. While a two phase power system is represented and the inductor component is configured as a dual inductor having two windings  104  and  106 , greater or fewer numbers of phases in the multi-phase power supply circuitry may alternatively be provided as illustrated in the following Figures, and a corresponding number of windings to the phases provided may be included in the magnetic core  102 . That is, and as explained below, the component may alternatively be configured for three, four or more windings for power systems including three or more phases. 
     It is understood that more than one inductor component including the core piece  102  and windings  104  and  106  may be provided on the board  110  as desired. Other types of circuit components may likewise be connected to the circuit board  110  to complete, for example, a power regulator circuit and/or a power converter circuit on the board  110 . As such power regulator and converter circuits are generally known and within the purview of those in the art, no further description of the circuitry is believed to be necessary. While not seen in  FIG. 1 , circuit traces are also included on the circuit board  110  on the other side of the power inductor component illustrated to establish electrical connection to load side circuitry  118  downstream from the conductive windings  104 ,  106  in the circuitry. 
     The magnetic core  102  in the example shown has includes a number of generally orthogonal sides imparting an overall rectangular or box-like shape and appearance. The size and shape of the core  102  shown in  FIG. 1  is the result of an assembled combination of modular magnetic core pieces described further below. The box-like shape of the magnetic core  102  in the illustrated example has an overall length L measured along a first dimensional axis such as an x axis of a Cartesian coordinate system, a width W measured along a second dimensional axis perpendicular to the first dimension axis such as a y axis of a Cartesian coordinate system, and a height H measured along a third dimensional axis extending perpendicular to the first and second dimensional axis such as a z axis of a Cartesian coordinate system. 
     The dimensional proportions of the magnetic core  102  runs counter to recent efforts in the art to reduce the height dimension H to produce as low profile components as possible. In higher power, higher current circuitry, as the height dimension H is reduced per recent trends in the art, the dimension W (and perhaps L as well) tends to increase to accommodate coil windings capable of performing in higher current circuitry. As a result, and following this trend, a reduction in the height dimension H tends to increase the width W or length L and therefore increase the footprint of the component on the board  110 . The assembly  100  of the present invention, however, favors an increased height dimension H (and increased component profile) in favor of a smaller footprint on the board  110 . As seen in the example of  FIG. 1 , the dimensions L and H are both much greater than the dimension W. Component density of the circuit board  110  may accordingly be increased by virtue of the smaller footprint of the component on the circuit board  110 . 
     As seen in  FIG. 1 , a portion of each of the coil windings  104  and  106  are each exposed on a side of the magnetic core  102  in a slightly recessed manner. The exposed coil windings  104  and  106  are relatively large in the x, y plane to capably handle higher current, higher power applications beyond the limits of conventional electromagnetic component constructions of an otherwise similar size. 
     In contemplated embodiments, the magnetic core  102  may be assembled from a selected number of modular magnetic core pieces such as those described below. The modular core pieces may be fabricated utilizing soft magnetic particle materials and known techniques such as molding of granular magnetic particles to produce the desired shapes. Soft magnetic powder particles used to fabricate the core pieces may include Ferrite particles, Iron (Fe) particles, Sendust (Fe—Si—Al) particles, MPP (Ni—Mo—Fe) particles, HighFlux (Ni—Fe) particles, Megaflux (Fe—Si Alloy) particles, iron-based amorphous powder particles, cobalt-based amorphous powder particles, and other suitable materials known in the art. In some cases, magnetic powder particles may be are coated with an insulating material such the core pieces may possess so-called distributed gap properties familiar to those in the art and fabricated in a known manner. The core pieces may be fabricated from the same or different magnetic materials and as such may have the same or different magnetic properties as desired. The magnetic powder particles used to fabricate the core pieces may be obtained using known methods and techniques and molded into the desired shapes also using known techniques. 
     Turning now to the exploded view of  FIG. 2 , the magnetic core  102  is seen to include two different shapes of modular magnetic core pieces arranged with the windings  104  and  106 , namely a pair of first magnetic core pieces  120  on either end of the assembly and a second magnetic core piece  122  in the middle. The core pieces  120  are identically shaped but inverted relative to one another in a mirror-image arrangement on either side of the core piece  122 , with the windings  104 ,  106  received between the core pieces  120  and  122 . 
     In the example shown, each magnetic core piece  120  is formed with opposing first and second longitudinal side walls  124  and  126 , opposing first and second lateral side walls  128  and  130  interconnecting the first and second longitudinal side walls  124  and  126 , and opposing top and bottom walls  132  and  134  interconnecting the respective first and second longitudinal side walls  124  and  126  and the respective first and second lateral side walls  128  and  130 . In the context of  FIGS. 1 and 2 , the “bottom” wall  134  in each piece  120  is located adjacent the circuit board  110  and the “top” wall is located at some distance from the circuit board  110 . Each piece  120  has a generally rectangular configuration including a generally planar top surface and a generally planar opposing bottom surface opposing the top surface and extending in the x, y plane of  FIG. 1  and parallel to the major surface of the circuit board  110 . 
     In the example pieces  120  shown, the surface of the lateral side wall  130  of each core piece is generally flat and planar, while the surface of the opposing longitudinal side wall  128  is shaped and contoured to receive the respective winding  104 ,  106  as described below. Moreover, and in the example shown, each of the bottom wall  134  and the top wall  132  is shaped and contoured to receive a portion of the windings  104 ,  106 . 
     More specifically, the lateral side wall  128  includes spaced-apart vertical slots  136 ,  138  extending in a direction generally parallel to the longitudinal side walls  124 ,  126  and perpendicular to the top wall  132  and the bottom wall  134 . The slots  136 ,  138  extend in a direction perpendicular to the surface of the lateral side wall  130  for a distance sufficient to receive the corresponding vertical portions of the respective windings  104 ,  106 . 
     The top wall  132  defines a recessed surface  140  extending to the ends of the slots  136 ,  138  in the lateral side wall  128 . The recessed surface  140  is inset and depressed from the surface of the top wall  132  such that where the recessed surface  140  resides the lateral side wall has a height dimension that is less than the height H of the remainder of the top surface  132 . The inset recessed surface  140  extends adjacent to and is accessible from the lateral side wall  128 , but is spaced from each of the lateral side walls  124 ,  126 . The surface  140  is recessed from, but extends generally parallel to the top wall  130  to accommodate a portion of the coil winding  104 ,  106  as explained below. 
     As shown in  FIG. 2 , the bottom wall  134  in each piece  120  includes a recessed surface  142  that extends to the lateral side  128  and to the slots  136 ,  138  therein. 
     The core piece  122  is seen in the Figures to be differently shaped from the core pieces  120  and essentially defines a solid dividing wall or separation wall between the windings  104 ,  106  and the core pieces  120 . The core piece  122  is formed with opposing first and second longitudinal side walls  150  and  152 , opposing first and second lateral side walls  154  and  156  interconnecting the first and second longitudinal side walls  150  and  152 , and opposing top and bottom walls  158  and  160  interconnecting the respective first and second longitudinal side walls  150  and  152  and the respective first and second lateral side walls  154  and  156 . In the context of  FIGS. 1 and 2 , the “bottom” wall  160  in the piece  122  is located adjacent the circuit board  110  and the “top” wall is located at some distance from the circuit board  110 . Unlike the core piece  120 , the lateral walls  150  and  152 , the longitudinal walls  154  and  156 , and the top and bottom walls  158 ,  160  of the core piece  122  are flat and planar, and are not shaped to receive any portion of the windings  104 ,  106 . 
     The windings  104 ,  106  are separated from one another on opposing sides of the core piece  122  by an amount sufficient to avoid magnetic coupling of the windings  104 ,  106  inside the completed core  102 . In a multi-phase power inductor application contemplated, magnetic coupling of the windings  104 ,  106  is undesirable as it may contribute to imbalanced inductance between the respective phases of power. 
     Each of the conductive windings  104  and  106  are formed as identically shaped and fabricated elements. Each winding  104 ,  106  is fabricated from a thin strip of conductive material that is bent or otherwise shaped or formed into the geometry shown. In the illustrated example, each winding  104 ,  106  includes a planar winding section  161  exposed on the top side  132  of each core piece  120  and first and second planar legs  162 ,  164  each extending perpendicular to the planar winding section  161  and opposing one another. As such, and in the illustrated example, the windings  104  and  106  are generally inverted U-shaped members with the section  161  being the base of the U and the legs  162 ,  164  extending downward from the section  161 . 
     In the illustrated embodiment, the legs  162 ,  164  are disproportionately longer that the section  161  along an axis of the winding. That is, the legs  162 ,  164  have a first axial length that is much larger than the axial length of the winding section  161 . For example, the axial length of the legs  162 ,  164  may be about three times the axial length of the section  161 , although this is not strictly necessary in all embodiments. The proportions of the windings  104 ,  106  facilitate a reduced footprint of the completed inductor component on the circuit board  110  as explained above, and the increased height of the windings  104 ,  106  provides a winding of sufficient length to capably handle higher current in a higher power electric system on the circuit board  110 . 
     In the example shown, ends of the legs  162 ,  164  in each winding  104 ,  106  are further formed to include surface mount termination pads  166 . The surface mount termination pads  166  extend perpendicularly to the plane of the legs  162 ,  164 , extend generally coplanar to one another, and extend parallel to but in a plane offset from the winding section  161 . In each winding, the surface mount termination pads  166  extend in opposite directions from one another. The surface mount termination pads  166  provide a larger area for surface mounting to the circuit board  110 , but in some cases may be considered optional and need not be provided. 
     The U-shaped windings  104 ,  106  are rather simply shaped and may be fabricated at low cost from a conductive sheet of material having a desired thickness into the three-dimensional shape as shown. The windings  104 ,  106  may be fabricated in advance as separate elements for assembly with the core pieces  120  and  122 . That is, the windings  104 ,  106  may be pre-formed in the shape as shown for later assembly with the core pieces  120  and  122 . The U-shaped windings  104 ,  106  define less than one complete turn in the magnetic core and are less complicated and more easily assembled than larger and more complex multi-turn coils. 
     To assemble the component, the winding  104  is assembled to the first core piece  120  and the winding  106  is assembled to the second core piece  120  by inserting the legs  162 ,  164  of each winding into the respective slots  136 ,  138  in the lateral side wall  128 . The winding section  161  is received over the recessed surface  140  in the top wall  132 , and the surface mount termination pads  166  are received in the recessed surfaces  142  on the bottom wall  134  in each core piece. Each core piece  120  receives the entire winding  104 ,  106  in the x dimension ( FIG. 1 ). The core pieces  102  including the windings  104 ,  106  are then arranged side-by-side with the core piece  122 . The lateral side walls  128  of each core piece  120  are bonded to the respective lateral side walls  154 ,  156  of the core piece  122 . The windings  104 ,  106  are then captured in place. When assembled, the surface mount termination pads  166  extend to, but not beyond the side walls  124 ,  126  of the core pieces  120  on the bottom side wall  134 . The footprint of the component on the circuit board  110 , as well as the profile of the component in the height dimension H, is therefore unaffected by the presence of the termination pads  166 . 
     Optionally, the core pieces  120  or  122  can be shaped to produce a physical gap in the assembled core  102  that may enhance energy storage in the component  100  in certain applications. For example, the area of the lateral side wall  128  in each core piece  120  between the slots  136 ,  138  may be formed with reduced dimension along the x axis relative to the remainder of the side wall  128 . Variations are possible to form different gaps of different sizes in various desired locations in the construction of the core  102 . 
     The exemplary inductor component assembly  100  is beneficial in at least the following aspects. The separately fabricated core pieces permit sliding assembly of the windings  104 ,  106  and relatively precise positioning thereof with relatively low cost. Assembly of the component is therefore simplified and manufacturing cost is lowered. The component assembly  100  is operable with balanced inductance between the different phases of electrical power connected to each winding while still reliably operating in higher power, higher current applications that modern day electrical devices demand. The assembly reduces, if not minimizes, fringing flux from conventionally employed discrete air gaps in the core structure, and ACR caused by fringing effect is accordingly reduced in operation of the assembly  100 . Higher power capability is provided with three dimensional conductive windings  104 ,  106  formed from planar conductive material and relatively simple core structure that has a relatively small footprint in combination with a relatively taller profile to accommodate higher power, higher current applications. Saturation current (I sat ) performance is enhanced. The component assembly  100  may be manufactured at relatively low cost, yet offer performance that many conventional power inductors are incapable of delivering. 
       FIGS. 3 and 4  illustrate additional exploded views of inductor component assemblies  200 ,  300  including the assembly  100  and illustrating the use of the modular core pieces  120  and  122  being arranged to easily configure the assembly to include additional windings. 
     In  FIG. 3 , a third core piece  120  is provided with a third winding  202  that is similar to the windings  104 ,  106 . The winding  202  is fitted with the third core piece  202  and is bonded to the lateral wall  130  of the core piece  120  on an end of the assembly  100  described above. The assembly  200  as shown is suited for a three-phase electrical power system with similar benefits to those described above. 
     In  FIG. 4 , the assembly  300  is further expanded to include a fourth core piece  120  and a fourth winding  302  that is similar to the windings  104 ,  106 . The winding  302  is fitted with the fourth core piece  202  and is bonded to the lateral wall  130  of the core piece  120  on an end of the assembly  200  described above. The assembly  300  as shown is suited for a four-phase electrical power system with similar benefits to those described above. 
     It should now be evident that the assembly is scalable to include still additional numbers of core pieces  120  and windings similar to the windings  104 ,  106 . Using only two different shapes of core pieces  120  and  122  and a set of windings having the same shape, inductor components can be assembled having any desired number of windings. 
       FIGS. 5-8  are various views of a second exemplary embodiment of a surface mount, power inductor component assembly  400  that may be used in lieu of or in combination with the assemblies  100 ,  200 ,  300  on the circuit board  110 . 
     The component assembly  400  includes a magnetic core fabricated from modular core pieces  404  and  406  with the windings  104  and  106  in between. The assembled core pieces  404  and  406  provide a component with similar proportions and overall dimensions to the core  102  described above, but with differently shaped modular core pieces. 
     In the exploded view of  FIG. 6 , the core pieces  404  are similar to the core pieces  120  but are reduced in the x dimension. As such, the pieces  104  each include slots  136 ,  138  in the lateral wall  128  and the recessed surface  140  in the top wall  132 . The pieces  404  receive the windings  104 ,  106  in a similar manner to that described above, but because of the reduced dimension of the pieces  404  in the x dimension, the slots  136 ,  138  receive only a portion of the winding legs  162 ,  164  and the winding section  161 . More specifically, each piece  404  receives about one-half of the winding legs  162 ,  164  and about one-half of the winding section  161  of each winding  104 ,  106  in the x dimension. 
     The core piece  406  in the assembly  400  is formed with opposing first and second longitudinal side walls  410  and  412 , opposing first and second lateral side walls  414  and  416  interconnecting the first and second longitudinal side walls  410  and  412 , and opposing top and bottom walls  418  and  420  interconnecting the respective first and second longitudinal side walls  410  and  412  and the respective first and second lateral side walls  414  and  416 . In the context of  FIGS. 5 and 6 , the “bottom” wall  420  in each piece  406  is located adjacent the circuit board  110  and the “top” wall  418  is located at some distance from the circuit board  110 . 
     The opposing lateral walls  414  and  416  of the core piece  4406  are shaped to receive a portion of the windings  104 ,  106 . Accordingly, each wall  414 ,  416  includes spaced apart vertical slots  422 ,  424  and the top wall  418  includes a recessed surface  426 . The slots  422 ,  424  and the recessed surface  426  on each opposing lateral wall  414  and  416  receives about one-half of the winding legs  162 ,  164  and about one-half of the winding section  161  of each winding  104 ,  106  in the x dimension. 
     The core pieces  406 ,  406  and the coil windings  106 ,  108  are inter-fit such that the vertical legs  162 ,  164  extend partly in the vertical slots  136 ,  138  in the core piece  404  and partly in the vertical slots  422 ,  424  of the core piece  406 . Likewise, the section  161  of the windings  106 ,  108  is received partly on the recessed surface  140  of the core pieces  404  and partly on the recessed surface  426  of the piece  406 . The core pieces  404 ,  406  are moved or drawn toward one other, with the vertical legs  162 ,  164  of the coil windings  106 ,  108  in the slots  136 ,  138  in each core piece  404 ,  406  until the lateral side walls  128 ,  414 ,  416  abut one another as seen in  FIG. 5 . The winding section  161  of the coil windings  106 ,  108  becomes seated in the inset depressed surfaces  140 ,  426  in each core piece  404 ,  406  as the core pieces  404 ,  406  are assembled. 
     As mentioned above, a physical gap may optionally be provided between the abutting core pieces  402 ,  404 ,  406  to enhance energy storage by, for example, reducing a dimension of the of the core pieces along the x axis in between the slots  136  and  138  and/or between the slots  422  and  424 . 
     In the illustrated embodiment, about half of each vertical leg  162 ,  164  and about half of the winding section  161  of the coil windings  106 ,  108  are accommodated in each core piece  404 ,  406 . The winding section  161  is exposed on the top surfaces  132  and  418  of each core piece  404  and  406  and the surface mount termination pads  166  are extended on both of the bottom surfaces of each core piece  404 ,  406 . 
     The benefits of the assembly  400  are similar to the benefits of the assembly  100  described above. 
       FIGS. 7 and 8  illustrate additional exploded views of inductor component assemblies  500 ,  600  including the assembly  400  and the use of additional core pieces  404  and  406  being arranged to easily expand configure the assembly to include additional windings. 
     In  FIG. 7 , a second core piece  406  is provided with a third winding  502  that is similar to the windings  104 ,  106 . The third winding  502  and second core piece  406  are fitted between the first core piece  404  of the assembly  100  and one core piece  406  in the middle of the assembly  400  as shown. The assembly  500  as shown is suited for a three-phase electrical power system with similar benefits to those described above. 
     In  FIG. 8 , the assembly  500  is further expanded to include a third core piece  406  and a fourth winding  602  that is similar to the windings  104 ,  106 . The fourth winding  602  is fitted with the third core piece  406  and another of the magnetic core pieces  406  in the middle of the assembly  500  as shown. The assembly  600  as shown is suited for a four-phase electrical power system with similar benefits to those described above. 
     It should now be evident that the assembly  400  is scalable to include still additional numbers of core pieces  406  and windings similar to the windings  104 ,  106 . Using only two different shapes of core pieces  404  and  406  and a set of windings having the same shape, inductor components can be assembled having any desired number of windings. 
       FIGS. 9-13  are various views of a third exemplary embodiment of a surface mount, power inductor component assembly  700  that may be used in lieu of or in combination with the assemblies  100 ,  200 ,  300 ,  400 ,  500 ,  600  on the circuit board  110 . 
     The component assembly  700  includes a magnetic core  702  fabricated from modular core pieces  704  and  706  with windings  708  and  710  in between. The assembled core pieces  704  and  706  provide a component with reduced proportions and overall dimension to the core  102  described above, particularly along the x axis and the length dimension L shown in  FIG. 1 . 
     In the exploded view of  FIG. 10 , the core pieces  704  are only slightly larger in the x dimension than the core piece  706 , which is similar to the core piece  122  described above in relation to  FIG. 2 . Like the previous embodiments, the pieces  704  each include spaced apart vertical slots  712 ,  714  in the lateral wall  716  facing the core piece  706 . The core pieces  704  also include a horizontal slot  718  interconnecting the vertical slots  712 ,  714  in a spaced relation from the top wall  720  of each core piece  704 . Compared to the previous embodiments, the slots  712 ,  714 ,  718  are wider and shallower. That is the slots  712 ,  714 ,  718  are not as deep to facilitate the reduction in the x dimension and are comparatively wider to accommodate the windings  708 ,  710  as further described below. A bottom wall  722  of each core piece  704  includes recessed surfaces  724  to accommodate a portion of the windings  708 ,  710   s.    
     Each of the conductive windings  708  and  710  are formed as identically shaped and fabricated elements. Each winding  708 ,  710  is fabricated from a thin strip of conductive material that is bent or otherwise shaped or formed into the geometry shown. In the illustrated example, each winding  708 ,  710  includes a planar horizontal winding section  730  and first and second planar vertical legs  732 ,  734  each extending from the planar horizontal winding section  730  and opposing one another. As such, and in the illustrated example, the windings  708  and  710  are generally inverted U-shaped members with the section  730  being the base of the U and the legs  732 ,  734  extending downward from the section  161 . Unlike the previously described windings, however, the vertical legs  732 ,  734  are coplanar with the horizontal section  730 . Accordingly, the dimension of the windings in the x dimension between the core pieces  704 ,  706  is greatly reduced as only the thickness of the material used to fabricate the windings  708 ,  710  occurs along the x dimension, as opposed to the larger width dimension of the windings  104 ,  106  seen in  FIG. 2 . 
     In the illustrated embodiment, the legs  732 ,  734  are disproportionately longer that the section  730  along an axis of the winding. That is, the legs  732 ,  734  have a first axial length that is much larger than the axial length of the winding section  730 . For example, the axial length of the legs  732 ,  734  may be about three times the axial length of the section  730 , although this is not strictly necessary in all embodiments. The proportions of the windings  708 ,  710  facilitate a reduced footprint of the completed inductor component on the circuit board  110  as explained above, and the increased height of the windings  708 ,  710  provides a winding of sufficient length to capably handle higher current in a higher power electric system on the circuit board  110 . The U-shaped windings  708 ,  710  define less than one complete turn in the magnetic core and are less complicated and more easily assembled than larger and more complex multi-turn coils. 
     In the example shown, ends of the legs  732 ,  734  in each winding  708 ,  710  are further formed to include surface mount termination pads  736 . The surface mount termination pads  736  extend perpendicularly to the plane of the legs  732 ,  734 , extend generally coplanar to one another, and extend in the same direction from each leg  732 ,  734 . The surface mount termination pads  736  provide a larger area for surface mounting to the circuit board  110 , but in some cases may be considered optional and need not be provided. As seen in  FIG. 13 , the surface mount termination pads  736  extend to each respective outside corner of the magnetic core  702   
     The U-shaped windings  708 ,  710  are rather simply shaped and may be fabricated at low cost from a conductive sheet of material having a desired thickness into the three-dimensional shape as shown. The windings  708 ,  710  may be fabricated in advance as separate elements for assembly with the core pieces  704  and  706 . That is, the windings  708 ,  710  may be pre-formed in the shape as shown for later assembly with the core pieces  704  and  706 . 
     To assemble the component, the magnetic core pieces  704  receive the windings  708 ,  710  in a similar manner to that described above. The winding legs  732 ,  734  are entirely received in the vertical slots  712 ,  714  and the section  730  of each winding  708 ,  710  is entirely received in the horizontal slot  718  in each piece  804 . The windings  708 ,  710  are, however, rotated 180° from one another so that the surface mount termination pads  736  extend beneath the respective pieces  704  with the surface mount termination pads  736  in the bottom recesses  724 . 
     The pieces  704  including the windings may then be assembled with and attached to the core piece  706  that separates the coils and prevents magnetic coupling of the coils in use. A physical gap may optionally be provided between the abutting core pieces  704 ,  706  to enhance energy storage as desired. Unlike the embodiments described above, the horizontal winding section  730  is not exposed on the exterior of the component. 
     The benefits of the assembly  700  are similar to the benefits of the assembly  100  described above. The assembly  700  is likewise scalable by adding additional magnetic core pieces  704  and windings similar to the windings  708 ,  710  to one end of the assembly. 
     The benefits and advantages of the invention are now believed to have been amply illustrated in relation to the exemplary embodiments disclosed. 
     An inductor component assembly for power supply circuitry on a circuit board has been disclosed including first and second magnetic core pieces formed and arranged as mirror images of one another, each of the first and second magnetic core pieces comprising a top side wall, a bottom side wall, and a vertical sidewall including a first vertical slot and a second vertical slot extending in spaced apart relation from the first vertical slot. The assembly also includes a first conductive winding assembled to the first magnetic core piece and a second conductive winding assembled to the second magnetic core piece. Each of the first and second conductive winding defines less than one complete turn including a planar winding section and first and second legs each extending from the planar winding section and opposing one another, wherein the first and second planar legs of each respective first and second conductive winding are respectively received in the first vertical slot and the second vertical slot in each of the first and second magnetic core pieces. The assembly also includes a third magnetic core piece interposed between the vertical side walls of the first magnetic core piece and the second magnetic core piece and separating the first and second conductive windings from one another. The third magnetic core piece is differently shaped from the first and second magnetic core pieces and includes opposed top and bottom walls and opposed vertical side walls extending between the top and bottom walls, wherein a height dimension of the third magnetic core piece between the top and bottom walls is substantially greater than a width or length dimension of the third magnetic core piece. The first conductive winding and the second conductive winding are not magnetically coupled to one another when connected to a multi-phase power supply circuit on the circuit board. 
     Optionally, the third magnetic core is not shaped to receive any portion of the first and second conductive windings. Alternatively, the first and second opposed vertical walls of the third magnetic core piece are each formed with a pair of vertical slots, and the pair of vertical slots each receive a portion of the first and second planar legs of each of the first and second conductive windings. The planar winding section of each of the first and second conductive windings may be exposed on the top wall of the third magnetic core piece. 
     As further options, in each of the first and second conductive winding, the planar winding section may have a first axial length and the first and second planar legs may have a respective second axial length, with the second axial length being substantially greater than the first axial length. Each of the first and second conductive windings may include first and second planar surface mount termination portions that extend coplanar to one another on the bottom side wall of at least the respective first and second magnetic core pieces. The surface mount terminations may extend to outside corners of the bottom wall of the respective first and second magnetic core pieces. Each of the first and second magnetic core pieces may include a recess to receive to the surface mount terminations. The first and second conductive windings may be formed from a planar conductive piece of material having a width, and the first and second vertical slots in the first and second magnetic core pieces may be dimensioned to receive the entire width. 
     As one option, the planar winding section and the first and second planar legs in each of the first and second conductive windings may extend coplanar to one another. As another option, the first and second planar legs may extend perpendicularly to the plane of the planar winding section. The third magnetic core piece may optionally receive both of the first and second conductive windings. 
     The inductor component assembly may further include a number n of additional magnetic core pieces and an equal number n of additional conductive windings, with each additional magnetic core piece formed identically to one of the first and second magnetic core pieces, and each additional conductive winding formed identically to the first and second conductive windings and fitted to each respective additional magnetic core piece on an end of the assembly. Alternatively, each additional magnetic core piece may be formed identically to the third magnetic core piece, and each additional conductive winding may be formed identically to the first and second conductive windings and fitted to each respective additional magnetic core piece at a position between the third magnetic core piece and one of the first and second magnetic core pieces. 
     Another embodiment of a surface mount inductor component assembly for power supply circuitry on a circuit board has been disclosed. The inductor component assembly includes: a number n of conductive windings each defining less than one complete turn including a planar winding section and first and second legs each extending from the planar winding section and opposing one another, wherein the planar winding section has a first axial length and the first and second planar legs have a respective second axial length, the second axial length being substantially greater than the first axial length; a plurality of first magnetic core pieces having at least one side wall including vertical slots dimensioned to receive at least the first and second planar legs; at least some of the number n of conductive windings fitted in the vertical slots; at least one second magnetic core piece differently shaped from the plurality of first magnetic core pieces, the at least one second magnetic core piece interposed between a pair of the first magnetic core pieces; and wherein the number n of conductive windings are not magnetically coupled to one another when connected to the circuit board. 
     Optionally, the planar winding section of each conductive winding may be exposed on an outer surface of at least one of the plurality of first magnetic core pieces. The planar winding section and first and second legs of each conductive winding may be coplanar to one another. The at least one second magnetic core piece may be configured to receive a pair of the number n of conductive windings. 
     A method of fabricating a surface mount inductor component assembly for power supply circuitry on a circuit board has also been disclosed. The method includes: selecting a number n of conductive windings from a pre-formed set of identical windings, each identical winding defining less than one complete turn and having a planar winding section and first and second legs each extending from the planar winding section and opposing one another, wherein the planar winding section has a first axial length and the first and second planar legs have a respective second axial length, the second axial length being substantially greater than the first axial length; assembling at least some of the selected number n of conductive windings with a plurality of first magnetic core pieces having at least one side wall including vertical slots dimensioned to receive at least the first and second planar legs; arranging at least one second magnetic core piece differently shaped from the plurality of first magnetic core pieces between at least one pair of the plurality of first magnetic core pieces; and bonding the first and second magnetic core pieces to one another; wherein the number n of conductive windings are spaced apart from one another by an amount sufficient to avoid magnetic coupling with one another when connected to the circuit board. 
     Optionally, the method may further include receiving first and second ones of the selected number n of conductive windings into opposing side walls of the at least one second magnetic core piece. 
     This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.