Method and apparatus for improving the efficiency of magnetic hybrid cores

Abstract

An inductor apparatus has at least one inductor coil encapsulated in a semiconductor packing material; the semiconductor packing material has a series of gaps in a row around the inductor coil; the gaps are coated in a magnetic hybrid material; and the semiconductor packing material encapsulating by the inductor coils is coated over the portions which cover the inductor coil. This inductor apparatus improves the efficiency with regard to wireless charging of wireless transmitters and receivers that utilize magnetic hybrid cores, as defined herein, by better directing the magnetic flux as it curves into the magnetic hybrid material.

Description

[0001] Title of the Invention

[0002] Method and Apparatus for Improving the Efficiency of Magnetic Hybrid Cores

[0003] Background of the Invention

[0004] [0001.] The field of the invention is related to inductors and, more specifically, to the form and position of magnetic material used to direct the flux generated by the inductors.

[0005] [0002.] Inductors allow for the use of magnetic flux to generate current. These properties have allowed for wireless charging where a transmitting inductor will induce magnetic flux in the area around the inductor, and this emanating magnetic flux will, in turn, induce current into another inductor placed within the area of the transmitting inductor.

[0006] [0003.] The emanating magnetic flux generally looks like the situation in FIG. 1, where there is a large area of flux 102 around inductor coils 101. These inductor coils 101 are shown in a crosssection and are shown on substrate 103, which holds the inductors in place. The magnetic material may be added around the inductor, and this has been found to be highly beneficial, as the addition of magnetic material will increase the inductance of the system.

[0007] [0004.] In general, for wireless charging, a transformer-like system is developed where the receiving inductor, as well as the transmitting inductor, contain a magnetic core so that when the two inductors are properly placed, the magnetic flux field is concentrated around the inductor coils. This is shown in FIG. 2 wherein the magnetic material 104 and 107 operates almost as a sort of backstop for the field, concentrating the flux 102 around the inductor coils 101 as the flux 102 now follows along the magnetic material.

[0008] [0005.] In FIG. 2, the magnetic materials and inductors are separated by a general space 106. It will be appreciated that this space occurs in the normal operation of wireless charging where there will be a space of some form between the two inductor coils, and that space may include air and some other material, for example, a phone plastic.

[0009] [0006.] As the magnetic flux 102 leaves the magnetic material 104 to enter the general space 106, it curves. As it leaves the general space 106 to enter magnetic material 107, it curves again to align with the direction of magnetic material 107. When the magnetic material is a ferrite, this turning of the flux does not present significant issues as the ferrite has an omnidirectional impedance that reduces the generation of parasitic eddy currents no matter what direction they form. However, when the magnetic material has a directional impedance, the parasitic currents may form as the curving magnetic flux changes the direction of the eddy currents. These eddy currents from the curving magnetic flux create a power inefficiency.

[0010] [0007.] There is a strong need to reduce the inefficiency of systems utilizing magnetic material with limited directions of impedance.

[0011] Brief Summary of the Present Invention

[0012] [0008.] What is presented here is an inductor apparatus and method of making an inductor apparatus that reduces the power inefficiency generated by curving magnetic flux in magnetic material that has limited directions of impedance as opposed to an omnidirectional impedance.

[0013] [0009.] This is more problematic when the magnetic material is a hybrid magnetic material, which is a metal material that has fine layers of porous insulation. Wherein the metal penetrates through the small holes in the insulation layer. These hybrid materials will only present impedance in the directions parallel to the insulation layers.

[0014] [0010.] To solve this problem, a series of magnetic material pillars are produced along the inductor coils that extend from the magnetic material "backboard" across some portion of the general gap. These pillars focus the magnetic material into a narrow position, limiting the area available for the magnetic flux to curve through and thus increasing the system's efficiency. These magnetic pillars also have the added benefit of reducing the distance of the gap and, depending on use, may increase the power efficiency of the system in that manner as well.

[0015] [0011.] It is worth noting that inductors will generally be held in semiconductor packing material. Therefore, the inductor apparatus presented herein may be understood to contain at least one inductor coil encapsulated in a semiconductor packing material where the semiconductor packing material has a series of gaps in a row around the inductor coil. The gaps are coated in a magnetic hybrid material, and the semiconductor packing material encapsulating by the inductor coils is coated over the portions that cover the inductor coil by the hybrid magnetic material. In general, the hybrid magnetic material could be replaced by a magnetic material, for example, metals; however, this does not reduce the system's inefficiencies because metals are highly conducive, leading to the formation of significant eddy currents.

[0016] [0012.] To further reduce the inefficiencies created by the eddy currents, the shape of the gaps may be altered. By altering the shape of the gaps, the covering of magnetic material will change shape, and the directional impedance it provides may be altered. Thus, rectangular shapes, trapezoidal shapes, triangular shapes, and many other shapes can be utilized for the gaps. The gaps may even have alternating shapes or shapes that differ from one another. Such shapes can improve the ability of the magnetic hybrid coating to follow the contours of the curving flux.

[0017] [0013.] It will be appreciated that when hybrid magnetic material is used as the coating for the gaps and as the magnetic "backstop," only a thin layer of magnetic material will be needed, and the thinness of this layer may change depending on the size and shape of the gap so that only up to twenty nanometers of hybrid magnetic material may be needed. Further, when the layer of magnetic material is so thin, the gaps may leave behind indentations in the backstop. These indentations may be filled, for example, with more magnetic hybrid material.

[0018] [0014.] It was noted above that the gaps could be placed around the inductor coil. These gaps may also be placed inside the inductor coils. The magnetic flux will travel on the inside, and the outside of the inductor coils as it loops around the coils. The number of gaps and rows of gaps may be varied as desired. For example, there may be multiple series (rows) of gaps around the inductor, for example, three or four.

[0019] [0015.] It is well known that some wireless chargers use multiple inductor coils; in such cases, when multiple inductors, it may be beneficial that the series of gaps occur within at least one center of at least one of the inductors.

[0020] [0016.] In general, during the process of making the inductor apparatus presented herein, the inductors or semiconductor packing material may be formed on a substrate, and that substrate may serve as a carrier which will be removed or serve as a more permanent base for the inductors and magnetic material.

[0021] [0017.] It will be appreciated that when you have two inductor apparatuses as described above, you may place them near each other, for example, within six inches, in a mirrored orientation. The mirrored orientation does not have to be perfect, but the inductors should be oriented so that one inductor is within the magnetic field of the other inductor without the magnetic hybrid backstop between the inductors. This will allow the inductors to operate as a wireless charger.

[0022] [0018.] There are several ways to make the inductor apparatus, as presented herein. As the inductor apparatus is novel and has a new structure, these ways are tailored to the inductor apparatuses.

[0023] [0019.] For example, one method of making an inductor apparatus comprises Forming an inductor on the surface of the substrate, encapsulating the inductor coil in a semiconductor packing material, drilling a series of gaps in the semiconductor packing material around an inductor coil of the inductor, and coating the gaps with a coating of a hybrid magnetic material. [0020.] This drilling can occur by laser drilling and may be useful for lowering costs and steps as well as for providing a greater variety of gap shapes as the inductor may have gaps in the center of the inductor as well as the outside of the inductor, gaps may also be drilled in the center of the inductor.

[0024] [0021.] Another example of a method of making an inductor apparatus comprises forming an inductor on the surface of the substrate, forming a series of pillars, the height of the pillars exceeding the height of the inductor, along at least one of the edges of the inductors; encapsulating the inductor and the pillars in a semiconductor packing material; grinding down the semiconductor packing material to expose an upper surface of the pillars; forming a series of gaps by etching out the pillars; covering the gaps in a hybrid magnetic material; and encapsulating the inductor coil in semiconductor packing material. It will be appreciated this is a more additive learning method of forming the inductor apparatus as it calls for the formation of pillars.

[0025] [0022.] As with the drilling method, gaps can be formed at the center of the inductor. Further, in both the drilling method and the pillar formation method, the substrate upon which the inductor or semiconductor packing material has been formed may serve as a carrier or a more permanent supporting substrate.

[0026] Brief Description of the Figures

[0027] [0023.] FIG. 1 is a perspective view of magnetic flux around a cross-section of an inductor coil.

[0028] [0024.] FIG. 2 is a perspective view of a particular magnetic flux line around two inductor sets that incorporate a magnetic core as a "backstop."

[0029] [0025.] FIG. 3 is a perspective view of a particular gently curving magnetic flux pathway and the eddy currents it generates in a two-inductor apparatus without the directional control of the magnetic material pillars.

[0030] [0026.] FIG. 4 is a perspective view of the area in which magnetic flux may concentrate with and without the direction control of the magnetic material pillars.

[0031] [0027.] FIG. 5 is a perspective view of a two-inductor apparatus with trapezoidal gaps coated with magnetic hybrid material, which forms the magnetic pillars.

[0032] [0028.] FIG. 6 is a perspective view of various gap shapes.

[0033] [0029.] FIG. 7 is a perspective view of a particular magnetic flux line around inductor coils, which incorporate a magnetic core as a "backstop" and incorporate the magnetic pillars. [0030.] FIG. 8 is a perspective view of a particular magnetic flux line around inductor coils of the same inductor, which incorporate a magnetic core as a "backstop" and incorporate the magnetic pillars where the area above the center of the inductor coils does not contain magnetic material including magnetic pillars.

[0034] [0031.] FIG. 9 is a perspective view of a particular magnetic flux line around inductor coils of the same inductor, which incorporate a magnetic core as a "backstop" and incorporate the magnetic pillars both inside and outside the inductor.

[0035] [0032.] FIG. 10 is a top-down perspective view of an inductor having a series of through holes around the outside edge as well as a series of through holes along the inside edge.

[0036] [0033.] FIG. 11 is a top-down perspective view of an inductor having two series of through holes around the outside edge of the inductor and one series of through holes on the inside of the inductor.

[0037] [0034.] FIG. 12 is a top-down perspective view of an inductor having four series of gaps around and in the center of the inductor.

[0038] [0035.] FIG. 13 is a perspective view of two inductor apparatuses placed in a mirrored orientation.

[0039] [0036.] FIG. 14 is a perspective view of a first step of the pillar etch method of forming the inductor apparatus presented herein. Where an inductor is connected to a carrier or substrate.

[0040] [0037.] FIG. 15 is a perspective view of a second step of the pillar etch method of forming the inductor apparatus presented herein. Wherein pillars have been formed on a carrier.

[0041] [0038.] FIG. 16 is a perspective view of a third step of the pillar etch method of forming the inductor apparatus presented herein. Wherein the pillars and inductor have been encapsulated in semiconductor packing material.

[0042] [0039.] FIG. 17 is a perspective view of a fourth step of the pillar etch method of forming the inductor apparatus presented herein. Wherein semiconductor packing material has been ground down to expose the pillars.

[0043] [0040.] FIG. 18 is a perspective view of a fifth step of the pillar etch method of forming the inductor apparatus presented herein. Wherein the pillars have been etched out— leaving gaps behind.

[0044] [0041.] FIG. 19 is a perspective view of a sixth step of the pillar etch method of forming the inductor apparatus presented herein. Wherein the gaps and a portion of the semiconductor packing material have been covered in a magnetic hybrid material. [0042.] FIG. 20 is a perspective view of a second step of the gap drill method of forming the inductor apparatus presented herein. Wherein the inductor has been encapsulated in semiconductor packing material.

[0045] [0043.] FIG. 21 is a perspective view of a third step of the gap drill method of forming the inductor apparatus presented herein. Wherein the semiconductor packing material has been drilled.

[0046] [0044.] FIG. 22 is a perspective view of a fourth step of the gap drill method of forming the inductor apparatus presented herein. Wherein the gaps and a portion of the semiconductor packing material have been covered in a magnetic hybrid material.

[0047] [0045.] FIG. 23 is a perspective view of an inductor encapsulated by semiconductor packing material with a pressing apparatus capable of forming gaps in the semiconductor packing material that is operationally placed above the semiconductor packing material.

[0048] [0046.] FIG. 24 is a perspective view of an inductor encapsulated by semiconductor packing material where the gaps are being plasma etched.

[0049] [0047.] FIG. 25 is a perspective view of an inductor encapsulated by semiconductor packing material where the gaps are being laser drilled.

[0050] Detailed Description of the Invention

[0051] [0048.] Presented herein is an apparatus and method to increase the efficacy of wireless charging systems and, more generally, to improve the ability to form a transformer in such cases where the inductors and the magnetic core are separated by some distance, as in the example given above of wireless charging.

[0052] [0049.] When an inductor apparatus is formed using hybrid magnetic material, which is a magnetic metal having a series of internal layers of thin insulation wherein these layers of insulation have gaps filled by the metal that allow the metal to fill and connect through the insulation layer to what would otherwise have been other layers of metal.

[0053] [0050.] FIG. 3 shows an inductor 110 and an inductor 111. The inductors 110 and 111 shown are made of a conductive hybrid material, and some thin insulation layers are visible. Inductor coils are separated into four groups, where 110 are of the same inductor and 111 represents another inductor. Above Inductor 110, there is a magnetic hybrid material 112, and below Inductor 111 there is a magnetic hybrid material 113. A magnetic flux line 102 is shown. It will be appreciated that there would be many magnetic flux lines running across the general space 106 (which is the space between the two inductor apparatuses). Eddy currents 114 run perpendicular to the magnetic flux line 102.

[0054] [0051.] It can be seen in FIG. 3 that the magnetic flux lines curve as they exit and enter the magnetic hybrid material 112 and 113, respectively. As eddy currents run perpendicular to the magnetic flux, for the insulation layers of the magnetic hybrid material to realize its full ability to reduce eddy current formation, the magnetic flux lines must run parallel to the insulation layers. (The insulation layers may somewhat reduce eddy currents from magnetic flux, which curves as long as the flux does not travel perpendicular to the insulation layers. However, as the magnetic flux angle changes from parallel to insulation layers, eddy currents will have more space to form.)

[0055] [0052.] FIG. 4 shows inductor 110 and inductor 111. Here the magnetic flux and eddy currents are removed, and instead, multiple main areas of magnetic hybrid material 112 and magnetic hybrid material 113 have been highlighted: area 114, area 115, areas 116, and areas 117. Areas 114 and 115 show the entry point for curving magnetic flux without the covered gaps of the present invention (referred to as indented pillars 118). Areas 116 and 117 show the entry points with the inductor apparatus present herein, as it has focused the magnetic flux in a smaller area. This reduces the total magnetic flux curvature in the system, thus increasing its efficiency.

[0056] [0053.] FIG. 5 shows inductors 110 and 111 with indented pillars 118. These indented pillars 118 are shown as magnetic hybrid material pillars. They direct the magnetic flux 102 between magnetic hybrid material 104 and 107 to narrow points and thus reduce the area the curvature of the magnetic flux 102 occupies. This reduces the ability of eddy currents to form. By using hybrid material in these indented pillars, eddy currents are reduced while the magnetic flux travels through the indented pillars.

[0057] [0054.] It can be seen that there are gaps between each of the pillars 118. FIG.

[0058] [0055.] As the indented pillars are responsible for focusing magnetic flux and reducing the area available for the flux to curve, it is worth spending some time on the design of the indented pillars.

[0059] [0056.] The indented pillars are indented because, as hinted above, they are the result of depositing layers on a gap. They may also be formed by depositing pillars on indentations or by pressing the hybrid magnetic material into the shape. They do not completely fill the indentation or gap they leave behind, so they are indented. These indents can be filled with a material, for example, a magnetic material, including a magnetic hybrid material.

[0060] [0057.] The general shape of the gaps or indents is worth considering.

[0061] [0058.] FIG. 6 shows several different gaps in semiconductor packing material 120. gap 121 is trapezoidal, gap 122 is a triangular gap. gap 123 is a pillar-shaped gap. Through 129 is a gap that does go through the semiconductor packing material 120. It is worth remembering that there are many possible gap dimensions. The shape of the gap will alter the shape of the magnetic material covering the gap, and several shapes might improve the efficiency of the flux lines by aligning the insulation layers more with the natural curve of the flux.

[0062] [0059.] gap 121 allows for magnetic hybrid material 119 covering the sides of gap 121 to have an angle that is an intermediary between a magnetic material "backstop" and the general gap. This is shown in FIG. 7. This allows for the insulation layering of the magnetic hybrid material to better match the pathway of magnetic flux and further reduce the formation and strength of eddy currents.

[0063] [0060.] FIG. 7 shows an inductor apparatus with trapezoidal gaps 121. The lines of insulation on the trapezoidal ease the flux curve 123 from the hybrid pillar to the magnetic "backstop" 114.

[0064] [0061.] FIG. 8 shows an inductor 111 in semiconductor packing material 120; there are several trapezoidal gaps 121 along the outside edge of the inductor 111. However, because magnetic flux 102 will flow in the center of the inductor 111 as well as the outside of the inductor, it may be useful to place a series of gaps covered in magnetic material in the center of the inductor. FIG. 9 shows an inductor 111 with several series of trapezoidal gaps 121 in the semiconductor packing material 120 covered with hybrid magnetic material 112. Although the hybrid material does not run the length of the component shown in FIG. 8 in at least one exemplary embodiment, it does so.

[0065] [0062.] A series of gaps has been referred to, and it is worth looking at what a series of gaps means. FIG. 10 shows a top-down view of an inductor 111 with a series of gaps 123 along the outside of the inductor 111 and a series of gaps 123 along the inside of the inductor 111. Here, a series means a row of gaps that follows the edge of the inductor. A series does not need to follow the entire edge of the inductor; it may follow a portion of the inductor edge. FIG. 11 shows two series of gaps 123 along the outside edge of the inductor and one along the inside edge of the inductor 111 each. A series can also refer to a grouping of inductors as seen in FIG. 12 where there are four groupings 125 of gaps in the semiconductor packing material (although this arrangement is not optimized.)

[0066] [0063.] Further, when the inductor has a center portion, it may be beneficial to not place any magnetic material over the center portion of the inductor. Therefore, in some cases of the inductor apparatus presented herein, there is no magnetic material of any sort over the center of the inductor.

[0067] [0064.] To use the inductor apparatus as a wireless receiver or transmitter, the inductor apparatus may be used to generate the magnetic field or placed within a generated magnetic field to produce current.

[0068] [0065.] As the inductor apparatus is useful for both being a transmitter and a receiver it is possible to have two inductor apparatus of the present invention and orient them so that one receives and one transmits. When using these two apparatuses, it is useful to place them so that they are oriented without magnetic material between them. This orientation is shown in FIG. 13 wherein a first inductor apparatus 100 and a second inductor apparatus 200 are oriented as a mirror of each other. In such cases when the gaps (here shown as pillar gaps 123) align as in the case of FIG. 13 the magnetic flux performance is optimized. These inductors will connect wirelessly across a general space 106.

[0069] [0066.] There are several novel methods to form an inductor apparatus of the present invention. In general, the determining factor of the number of steps of the process is the method used to form the gaps. The first is an additive method that requires the placement of pillars which are then etched out to form gaps, and the second of which is a simple drilling process that is used to form the gaps. There is also a third method of forming gaps by stamping, and this is useful for quickly creating indents.

[0070] [0067.] The first method is shown in FIG. 14-19. Here FIG. 14 shows the inductor 111 has been formed on substrate 103. The inductor may be formed in this manner by placing or building an inductor on a substrate. FIG. 15 shows a series of pillars 131, typically copper pillars, but of some etchable material, placed onto the substrate 103. These pillars 131 will become the gaps (here pillar-shaped gaps 124.) Note that the height of the pillars 131 exceeds the height of the inductor coils 111.

[0071] [0068.] FIG. 16 shows a semiconductor packing material 120 has been placed over the pillars 131. This semiconductor packing material may be any semiconductor packing material, but in at least one case is Ajinomoto Build-Up Film. FIG. 17 shows the semiconductor packing material 120 has been ground down to expose the pillars 131. FIG. 18 shows the pillars have been etched out and replaced by gaps 124.

[0072] [0069.] FIG. 19 shows that a magnetic hybrid layer deposition process has been performed to coat the gaps 124 and the semiconductor packing material 120 with magnetic hybrid material 112. However, portion 132 of the semiconductor packing material 120 has been left exposed as this is over the center of the inductor.

[0073] This completes the fundamental process of building the inductor apparatus by the pillar formation and etch method. However, further steps may be undergone, for example, removing the substrate (which in this case will have merely been a carrier), t

[0074] [0070.] The second method is shown in FIG. 20 - 22 Here FIG. 20 shows an inductor 111 in semiconductor packing material 120. FIG. 21 shows several drilled trapezoidal gaps 121. The gaps 121 may have been drilled by lasers, and this is a cost-effective process. As shown in FIG 22 the gaps 121, as well as the semiconductor packing material, are plated with magnetic hybrid material 112. This is a less step-intensive and more cost-effective method than the pillar formation method, although the pillar formation method can provide a greater level of precision in gap formation.

[0075] [0071.] The third method of forming the inductor apparatus is by pressing the gaps. The gaps may be pressed or stamped into the semiconductor packing material, and the semiconductor packing material is then plated with magnetic hybrid material. Or the magnetic hybrid material may be stamped onto the semiconductor packing material so that the magnetic material is left on the semiconductor packing material with proper gaps in place. An Inductor and stamp machine are shown in FIG. 23, where stamp machine 300 is over inductor apparatus 100. The protrusions 301 of the stamp machine 300 will produce the gaps 121 of the inductor apparatus 100 when the stamp machine 300 is pressed into the semiconductor packing material of 120.

[0076] [0072.] According to various embodiments other forms of lithography, etching, or drilling may be used as well, for example, an exemplary embodiment of the present invention utilizes plasma etching to create the gaps of the present invention. Here a pattern 2401 is placed for the pillars patterned as shown in FIG. 24, the plasma 2402 is generated and creates the gaps. For another example, laser drilling is also a viable solution for creating the gaps in at least one exemplary embodiment of the present invention. This is shown in FIG. 25 where lasers 2501 drill substrate 120. These examples are not limiting, and as notepad bocce various other forms of lithography, etching, or drilling, may be used.

[0077] [0073.] One of the ordinary skills in the art would understand that this apparatus could be incorporated into systems that may have additional layers in the semiconductor packing material or have layers or components connected to or around the inductor apparatus.

Claims

Claims1. An inductor apparatus at least one inductor coil is encapsulated in a semiconductor packing material; the semiconductor packing material has a series of gaps in a row around the inductor coil; the gaps are coated in a magnetic hybrid material; and the semiconductor packing material encapsulating the inductor coils is coated over the portions which cover the inductor coil.

2. The inductor apparatus of claim 1, wherein the shape of the gaps is rectangular.

3. The inductor apparatus of claim 1, wherein the shape of the gaps is trapezoidal.

4. The inductor apparatus of claim 1, wherein the shape of the gaps is triangular.

5. The inductor apparatus of claim 1, wherein the shape of the gaps alternates among the series of gaps.

6. The inductor apparatus of claim 1, wherein the coating of magnetic hybrid material is twenty nanometers thin or thinner.

7. The inductor apparatus of claim 1, wherein the inductor coils are a hybrid conductive material8. The inductor apparatus of claim 1, further comprising a substrate operationally attached to at least the semiconductor packing material.

9. The inductor apparatus of claim 1, further comprising a substrate operationally attached to at least the inductor coils.

10. The inductor apparatus of claim 1, wherein a material fills the gaps.11 . The inductor apparatus of claim 10, wherein the material is a magnetic hybrid material.

12. The inductor apparatus of claim 1, further comprising at least one additional row of gaps.

13. The inductor apparatus of claim 12, further comprising at least one additional row of gaps on at least an inside hole of the inductor coils.

14. The inductor apparatus of claim 1, further comprising at least two inductor coils wherein the series of through-holes occurs within at least one center of the inductor coils.

15. The inductor apparatus of claim 1, further comprising a second inductor apparatus comprising; at least one inductor coil encapsulated in a semiconductor packing material; the semiconductor packing material having a series of gaps around the inductor coils; the gaps are coated in magnetic hybrid material; and the semiconductor packing material encapsulating by theinductor coils is coated over those portions which cover the inductor coil; placed within 6 inches of the first inductor apparatus in a mirrored orientation from the first inductor.

16. A method of making an inductor apparatus, comprising; forming an inductor on the surface of the substrate; encapsulating the inductor coil in a semiconductor packing material; forming a series of gaps in the semiconductor packing material around an inductor coil of the inductor; and coating the gaps with a coating of hybrid magnetic material17. The method of claim 16 further comprising drilling a series of gaps in the packaging material in the center of at least one of the inductor coils and coating the series of gaps in the packaging material in the center of at least one of the inductor coils with the hybrid magnetic material.

18. The method of claim 16 wherein the formation of the series of gaps is performed by a laser drill.

19. A method of making an inductor apparatus, comprising; forming an inductor on the surface of the substrate; forming a series of pillars, the height of the pillars exceeding the height of the inductor; along at least one of the edges of the inductors; encapsulating the inductor and the pillars in a semiconductor packing material; grinding down the semiconductor packing material to expose an upper surface of the pillars; forming a series of through-holes by etching out the pillars; covering the gaps in a hybrid magnetic material; and encapsulating the inductor coil in a semiconductor packing material.

20. The method of making an inductor apparatus of claim 19, further comprising removing the substrate.

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