Apparatus for establishing inductive coupling in an electrical circuit and method of manufacture therefor

Information

  • Patent Grant
  • 6727794
  • Patent Number
    6,727,794
  • Date Filed
    Saturday, September 22, 2001
    23 years ago
  • Date Issued
    Tuesday, April 27, 2004
    20 years ago
Abstract
An apparatus for establishing inductive coupling in an electrical circuit arranged on a plurality of dielectric substrates, the substrates being in a substantially abutting relationship and presenting a plurality of substantially parallel planar expanses, includes: (a) at least one first core segment situated in at least one first depression provided in a first planar expanse; (b) at least one second core segment situated in at least one second depression provided in a second planar expanse; (c) a selected second core segment is arranged for establishing magnetic flux coupling with a selected first core segment to establish a magnetic core structure; (d) a plurality of electrically conductive through-hole structures traverse at least one substrate; (e) a plurality of electrically conductive circuit traces are arrayed upon at least two of the planar expanses. The conductive traces and the through-hole structures cooperate to establish inductive coupling.
Description




BACKGROUND OF THE INVENTION




The present invention is directed to electrical inductive circuit elements, such as inductors and transformers, and especially to small electrical inductive circuit elements having a low profile that may be reliably and economically manufactured in production quantities.




Prior art inductive elements that require a magnetic core structure commonly provide a cutout aperture through a dielectric substrate for insertion of a ferromagnetic or other magnetic core structure. The core structure may already bear the required windings for effecting inductive coupling, or the required windings may be incorporated into circuit traces arrayed upon the substrate. There are problems with using such a structure, especially in applications where small inductive circuitry having a low profile is desired. Chief among the problems with such an approach are the room required to accommodate an inductive element and its supporting electrical circuitry. In addition, the large size of prior art inductive circuitry necessitates situating associated circuit elements a distance removed from the inductive element. Such physical separation among circuit elements introduces capacitance and inductance into the circuit as well as increased trace lengths, all of which may contribute to increased losses. Such an introduction of capacitive and inductive factors into circuitry is a problem in power supply output circuits as well as in any LC (inductance-capacitance) filter application; the increased capacitances and inductances reduce transient response of such circuits and increase losses.




An attempt to ameliorate the problems associated with assembling inductive circuit elements is described in U.S. Pat. No. 5,781,091 issued Jul. 14, 1998 to Krone, et al. for “Electronic Inductive Device and Method for Manufacturing”. Krone, et al. describe an assembly structure and process for manufacturing that structure that provides an inner board layer with an aperture. The apertured inner board layer is situated atop a laminate that includes an insulating layer and a copper foil layer. The insulating layer faces the inner board. The aperture is partially filled with a thin layer of fiber filled epoxy and a ferromagnetic core is installed within the aperture atop the fiber filled epoxy layer. Another layer of fiber filled epoxy is added on top of and within the center of the core completely covering the core and embedding the core in the fiber filled epoxy, an insulating material. A second laminate similar to the first laminate is then applied atop the inner board to complete a board stack, with the insulating layer of the second laminate facing the inner board.




Plated through-hole structures are provided traversing the board stack; circuit traces are created on outer faces of the board stack by etching the copper foil layers. The circuit traces are connected with the through-hole structures to establish electrical paths that encircle the core thereby establishing an inductive coupling circuit with the core.




One shortcoming of the Krone, et al. structure relates to the employment of fill material within the aperture that covers the core. The magnetic core is placed within an aperture that is filled with a material that is at least somewhat viscous at temperatures encountered during processing steps contemplated by Krone et al. As a consequence, the core is liable to “float” within the aperture during processing. The varied positioning that a core may assume during processing because of such an ability to float means that the through-hole structures required by Krone et al. for forming loops about the core for inductive coupling may not be placed with respect to the core to avoid intercepting the core. That is, the cores can float sufficiently that one may intercept the core while drilling or otherwise forming the through-holes. This placement precision limitation presents less of a problem for inductive devices that are sufficiently large. However, for inductors that are small enough to be useful in today's circuits for such applications as board mounted power supply products or the like, the size of the core is sufficiently small that manufacturing yields for such products will be too low to make the use of the Krone et al. structure an economically worthwhile approach. Further, the tolerances that are required for producing the Krone et al. structure are likely to be too large to permit fabrication of products small enough for use as board mounted power supply products.




There is a need for an improved structure for electrical inductive element and method for manufacture of the element that provides precision manufacturing of small power products with tightly controllable tolerances.




SUMMARY OF THE INVENTION




An apparatus for establishing inductive coupling in an electrical circuit arranged on a plurality of dielectric substrates, the plurality of dielectric substrates being in a substantially abutting relationship and presenting a plurality of substantially parallel planar expanses, includes: (a) at least one first core segment situated in at least one first depression provided in a first planar expanse of the plurality of planar expanses; (b) at least one second core segment situated in at least one second depression provided in a second planar expanse of the plurality of planar expanses; (c) a selected second core segment arranged for establishing magnetic flux coupling with a selected first core segment to establish a selected magnetic core structure; (d) a plurality of electrically conductive through-hole structures traversing at least one substrate of the plurality of substrates; (e) a plurality of electrically conductive circuit traces arrayed upon at least two planar expanses of the plurality of planar expanses. The plurality of conductive traces and the plurality of through-hole structures cooperate to effect establishing inductive coupling.




The method for manufacturing the apparatus produces an electrical circuit arranged on at least one dielectric substrate. The electrical circuit establishes inductive coupling with a magnetic core structure. The at least one substrate presents a plurality of substantially parallel planar expanses. The method includes the steps of: (a) providing at least one substrate; (b) creating a first depression in a first planar expanse of the plurality of planar expanses; (c) creating a second depression in a second planar expanse of the plurality of planar expanses; a portion of the second depression being substantially in register with a portion of the first depression; (d) situating a first core segment in the first depression; (e) situating a second core segment in the second depression; the first core segment effects magnetic flux coupling with the second core segment to establish a magnetic core structure; (f) providing a plurality of electrically conductive circuit traces arrayed on at least two of the planar expanses; (g) providing a plurality of electrically conductive through-hole structures traversing at least one substrate; (h) coupling the plurality of conductive traces and the plurality of through-hole structures to effect establishing inductive coupling.




It is, therefore, an object of the present invention to provide an apparatus for establishing inductive coupling in an electrical circuit, and a method for manufacture therefor, that facilitates precision manufacturing of small power products with tightly controllable tolerances.




Further objects and features of the present invention will be apparent from the following specification and claims when considered in connection with the accompanying drawings, in which like elements are labeled using like reference numerals in the various figures, illustrating the preferred embodiments of the invention.











BRIEF DESCRIPTION OF THE DRAWINGS





FIG. 1

is a perspective exploded view illustrating a prior art inductive circuit element poised for assembly.





FIG. 2

is a side view of the inductive circuit element of

FIG. 1

in an assembled orientation.





FIG. 3

is a top plan view of the preferred embodiment of an inductive circuit element according to the present invention.





FIG. 4

is a side view of the inductive element of FIG.


3


.





FIG. 5

is a perspective view of the preferred embodiment of a core segment for use with the present invention.





FIG. 6

is a simplified side view of the inductive circuit element illustrated in

FIG. 3

showing an alternate placement arrangement for magnetic core segments.





FIG. 7

is a simplified side view of the inductive circuit element illustrated in

FIG. 3

showing a second alternate placement arrangement for magnetic core segments.





FIG. 8

is a simplified side view of the inductive circuit element illustrated in

FIG. 3

showing a third alternate placement arrangement for magnetic core segments.





FIG. 9

is a plan view of a representative circuit layout illustrating an alternate structure for fixing position of a core segment in a product.











DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT




For purposes of this description throughout, the term “magnetic” is considered to be substantially synonymous with the terms “ferrous”, “ferromagnetic”, and “magnetizable”.





FIG. 1

is a perspective exploded view illustrating a prior art inductive circuit element poised for assembly. In

FIG. 1

, an inductive circuit element


10


includes a printed wiring board substrate


12


, and ferrite elements


14


,


16


. Substrate


12


has an aperture


20


therethrough. Ferrite elements


14


,


16


are preferably substantially symmetric. Ferrite element


14


includes a pair of raised end portions


22


,


24


extending from a base portion


25


. Ferrite element


16


includes a pair of raised end portions


26


,


28


extending from a base portion


29


. Ferrite element


16


includes a center post


30


extending from base portion


25


in the same direction as end portions


22


,


24


extend. Ferrite element


14


has a similar center post extending from base portion


29


in the same direction as end portions


26


,


28


extend (not visible in FIG.


1


).




During assembly ferrite elements


14


,


16


are positioned together with substrate


12


between ferrite elements


14


,


16


. Center post


30


(and its mating center post extending from ferrite element


14


meet through aperture


20


. End portions


22


,


26


meet at a cutout


32


provided in substrate


12


. End portions


24


,


28


meet at a cutout


23


provided in substrate


12


.




A clip


40


may be provided to securely grippingly assemble substrate


12


with ferrite elements


14


,


16


. Other attachment mechanisms may be employed in assembling inductive circuit element


10


, such as adhesive between raised end portions


22


,


26


, between raised end portions


24


,


28


and between center post


30


and a similar center post on ferrite element


14


(not visible in FIG.


1


).




Windings (not shown in

FIG. 1

) may be arranged about ferrite elements


14


,


16


or arranged about center post


30


(and its mating center post extending from ferrite element


14


; not visible in

FIG. 1

) to establish inductive coupling with ferrite elements


14


,


16


. Windings may be embodied in a variety of structures (not shown in FIG.


1


). For example, windings may be embodied in a winding bundle nestled about center post


30


and its mating center post extending from ferrite element


14


. Another example of an embodiment of a winding structure for effecting inductive coupling with ferrite elements


14


,


16


is one or more circuit traces arranged on substrate


12


.





FIG. 2

is a side view of the inductive circuit element of

FIG. 1

in an assembled orientation. In

FIG. 2

, inductive circuit element


10


includes substrate


12


situated between ferrite elements


14


,


16


. Clip


40


holds substrate


12


, and ferrite elements


14


,


16


in a unitary package. Inductive circuit element


10


extends a thickness t measured across the maximum expanse from ferrite element


14


to ferrite element


16


. It is the thickness t that needs reduction in order that inductive circuit element


10


may be better employed in the increasingly compact products being required today. That is, reduction of thickness t makes inductive circuit element


10


a lower profile circuit element.





FIG. 3

is a top plan view of the preferred embodiment of an inductive circuit element according to the present invention. In

FIG. 3

, an inductive circuit element


50


includes a base member


52


and magnetic or ferromagnetic core segments


60


,


62


,


64


,


66


arrayed in base member


52


. Each of core segments


60


,


62


,


64


,


66


is a substantially U-shaped element having a base or bight section and a pair of legs extending from the base or bight member. Core segments may be configured to result in an “EI” core element, or an “EE” core element or another shape of core element. The U-shaped element formed by core segments


60


,


62


,


64


,


66


is described here by way of example and not by way of limitation. Thus, core segment


60


has a base or bight member


60




a


and legs


60




b


,


60




c


extending from base member


60




a


to leg ends


60




d


,


60




e


. Core segment


62


has a base or bight member


62




a


and legs


62




b


,


62




c


extending from base member


62




a


to leg ends


62




d


,


62




e


. Core segment


64


has a base or bight member


64




a


and legs


64




b


,


64




c


extending from base member


64




a


to leg ends


64




d


,


64




e


. Core segment


66


has a base or bight member


66




a


and legs


66




b


,


66




c


extending from base member


66




a


to leg ends


66




d


,


66




e


. Core segments


60


,


62


are situated appropriately with legs


60




b


,


62




b


in overlapping relationship and with legs


60




c


,


62




c


in overlapping relationship to establish magnetic flux coupling and cooperate to establish a ferromagnetic core structure


70


. Core segments


64


,


66


are situated appropriately with legs


64




b


,


66




b


in overlapping relationship and with legs


64




c


,


66




c


in overlapping relationship to establish magnetic flux coupling and cooperate to establish a ferromagnetic core structure


72


.




Electrically conductive through-hole structures


80


,


82


,


84


,


86


,


88


traverse base member


52


to provide electrical continuity through base member


52


. Circuit traces are arrayed on base member


52


to complete electrical circuit paths that cooperate with through-hole structures


80


,


82


,


84


,


86


,


88


and ferromagnetic core structures


70


,


72


in effecting inductive coupling. The inductive coupling that may be effected by such cooperation may establish an inductor structure, a transformer structure or another inductively coupled structure.

FIG. 3

(and

FIG. 4

) illustrates an inductive coupling embodied in a 2:1 transformer structure. Thus, a circuit trace


90


representing, for example, a primary turn in a transformer includes a trace segment


90




a


on the top side of base member


52


from a start locus


91


to connect with through-hole structure


82


. Such connection (and other similar connections or couplings described herein) are preferably effected using solder coupling; other electrical coupling technologies may also be employed. A second trace segment


90




b


on the bottom side of base member


52


couples through-hole structure


82


with through-hole structure


84


. Another trace segment


90




c


on the top side of base member


52


couples through-hole structure


84


with through-hole structure


88


. Yet another trace segment


90




d


on the bottom side of base member


52


couples through-hole structure


88


with an end locus


93


.




In such manner, there is a continuous electrical path established by circuit trace


90


in cooperation with through-hole structures


82


,


84


,


88


to establish a single turn of an electrical conductor through ferromagnetic core structure


70


and establish a single turn of an electrical conductor through ferromagnetic core structure


72


. Electrical connection may be made with start locus


91


and end locus


93


to include primary circuit trace


90


in an external electrical circuit (not shown in FIG.


3


).




A second circuit trace


92


representing, for example, secondary turns in a transformer includes a trace segment


92




a


on the top side of base member


52


from a start locus


95


to connect with trace segments


92




b


,


92




c


. Trace segment


92




b


on the top side of base member


52


connects trace segment


92




a


with through-hole structure


86


. Trace segment


92




c


on the top side of base member


52


connects trace segment


92




a


with through-hole structure


80


. A trace segment


92




d


on the bottom side of base member


52


couples through-hole structures


80


,


86


with an end locus


97


.




In such manner, there is a continuous electrical path established by circuit trace


92


in cooperation with through-hole structures


80


,


86


to establish two parallel single turns of an electrical conductor through ferromagnetic core structures


70


,


72


. Electrical connection may be made with start locus


95


and end locus


97


to include secondary circuit trace


92


in an external electrical circuit (not shown in FIG.


4


).





FIG. 4

is a side view of the inductive element of FIG.


3


. In

FIG. 4

, inductive circuit element


50


is arrayed in a base member


52


. Base member


52


includes a top substrate


53


and a bottom substrate


55


. Through-hole structures


80


,


82


,


84


,


86


,


88


traverse top substrate


53


and bottom substrate


55


to provide electrical continuity among circuit traces


90


,


92


as described by way of example in the exemplary circuit trace structure illustrated in

FIG. 3

(only portions of circuit traces


90


,


92


are visible in FIG.


4


).




Depressions


40


,


44


are established in top substrate


53


appropriately dimensioned to nestlingly receive magnetic core segments


60


,


64


. Depressions


42


,


46


are established in bottom substrate


55


appropriately dimensioned to nestlingly receive magnetic core segments


62


,


66


. Depressions


40


,


44


partially extend into top substrate


53


leaving a distance d


1


separation from depressions


40


,


42


to the lower boundary


54


of top substrate


53


. Depressions


42


,


46


partially extend into bottom substrate


55


leaving a distance d


2


separation from depressions


42


,


46


to the lower boundary


56


of bottom substrate


55


. By such an arrangement a separation distance d


1


is established between depressions


40


,


42


and between depressions


44


,


46


, so that a similar separation distance d


1


is established between magnetic core segments


60


,


62


and between magnetic core segments


64


,


66


. Separation distance d


1


is preferably established at a dimension to permit magnetic flux coupling between magnetic core segments


60


,


62


and between magnetic core segments


64


,


66


.




Magnetic core segments


60


,


62


,


64


,


66


have respective upper faces


73


,


75


,


77


,


79


. Preferably, magnetic core segments


60


,


62


,


64


,


66


are proportioned to be substantially fully received within respective depressions


40


,


42


,


44


,


46


so that magnetic core segments


60


,


62


,


64


,


66


present respective upper faces


73


,


75


,


77


,


79


substantially flush with associated substrates


53


,


55


.





FIG. 5

is a perspective view of the preferred embodiment of a core segment for use with the present invention. In

FIG. 5

, a magnetic core segment


560


is preferably a substantially planar ferrous piece having a base or bight member


560




a


and legs


560




b


,


560




c


extending from base member


560




a


to leg ends


560




d


,


560




e


. In its preferred embodiment magnetic core segment


560


is a pliable magnetic material. Examples of such pliable magnetic material include magnetically loaded paste materials and magnetically loaded composite sheet materials, such as ferrite polymer composite materials. The magnetic materials of which magnetic core segment


560


is made may include a distributed air gap within the material. Such a distributed air gap construction facilitates establishing a plurality of magnetic core segments


560


(see, for example, magnetic core segments


60


,


62


and magnetic core segments


64


,


66


;

FIGS. 3 and 4

) to provide a magnetic reluctance path on one layer (e.g., top substrate


53


;

FIG. 4

) that is transferred to another layer (e.g., bottom substrate


55


; FIG.


4


). By making magnetic core segments


560


using magnetic material having a distributed air gap, there need not be an air gap provided in inter-layer transitions of a magnetic element. By way of example, magnetic core segments


60


,


62


(

FIGS. 3 and 4

) could be situated in facing abutting relationship at lower boundary


56


of top substrate


53


, if desired, if magnetic core segments


60


,


62


are manufactured using such a material having a distributed air gap.





FIG. 6

is a simplified side view of the inductive circuit element illustrated in

FIG. 3

showing an alternate placement arrangement for magnetic core segments. In

FIG. 6

, an inductive circuit element


650


is arrayed in a base member


652


. Base member


652


includes a top substrate


653


, a bottom substrate


655


and a middle substrate


657


.




Depressions


640


,


644


are established in top substrate


653


appropriately dimensioned to nestlingly receive magnetic core segments (e.g., magnetic core segments


60


,


64


; FIG.


3


). Depressions


642


,


646


are established in bottom substrate


655


appropriately dimensioned to nestlingly receive magnetic core segments (e.g., magnetic core segments


62


,


66


; FIG.


3


). Depressions


640


,


644


partially extend into top substrate


653


leaving a distance d


1


, separation from depressions


640


,


644


to the lower boundary


654


of top substrate


653


. Depressions


642


,


646


partially extend into bottom substrate


655


leaving a distance d


2


separation from depressions


642


,


646


to the lower boundary


656


of bottom substrate


655


. Middle substrate


657


has a thickness d


3


. By such an arrangement a separation distance (d


1


+d


3


) is established between depressions


640


,


642


and between depressions


644


,


646


, so that a similar separation distance (d


1


+d


3


) is established between magnetic core segments situated within depressions


640


,


642


and between magnetic core segments situated within depressions


644


,


646


. Separation distance (d


1


+d


3


) is preferably established at a dimension to permit magnetic flux coupling between magnetic core segments situated within depressions


640


,


642


and between magnetic core segments situated within depressions


644


,


646


.





FIG. 7

is a simplified side view of the inductive circuit element illustrated in

FIG. 3

showing a second alternate placement arrangement for magnetic core segments. In

FIG. 7

, an inductive circuit element


750


is arrayed in a base member


752


. Base member


752


is a single substrate having a top face


771


and a bottom face


773


.




Depressions


740


,


744


are established in top face


771


appropriately dimensioned to nestlingly receive magnetic core segments (e.g., magnetic core segments


60


,


64


; FIG.


3


). Depressions


742


,


746


are established in bottom face


773


appropriately dimensioned to nestlingly receive magnetic core segments (e.g., magnetic core segments


62


,


66


; FIG.


3


). Depressions


740


,


744


partially extend into base member


752


from top face


771


. Depressions


742


,


746


partially extend into base member


752


from bottom face


773


. A separation distance d


1


is thereby established between from depressions


740


,


742


and between depressions


744


,


746


. Separation distance d


1


is preferably established at a dimension to permit magnetic flux coupling between magnetic core segments situated within depressions


740


,


742


and between magnetic core segments situated within depressions


744


,


746


.




The advantages of manufacturing an inductive circuit element according to the structure and method disclosed in this specification include having an inductive circuit element with its magnetic core elements situated within its substrate or substrates. Thus there is provided a low profile device. In fact, the resulting device has no profile other than the substrates and other items carried thereon, such as capacitors, circuit traces and other similar electrical or electronic components. The bulky profile presented by prior art devices is eliminated.




An additional benefit of the structure and method of the present invention is that there is more “real estate” made available for circuit traces, components and other items. That is more area is available using the structure or method of the present invention than is available using prior art approaches for placing circuit parts and connecting them to create a product. This advantageous result is achieved principally because the “real estate” in the vicinity of the core elements is substantially fully available for carrying circuitry.




The availability of areas proximate to the core elements is also important because it facilitates locating components used in connection with or in support of the inductive circuit element in locations closely adjacent with the core elements. For example, when the inductive circuit element of the present invention is used in an LC (inductive capacitive) filter application, the additional inductances, capacitances and resistance that may occur because of supporting components and circuit traces necessary to connect the various components are reduced. Such “stray” inductances, capacitances and resistance are significantly reduced by using the structure or method of the present invention, and transient response of the circuit is improved because of the nearly adjacent location of components and the core of the inductive circuit element.




The advantages of low profile and available real estate are also available when the present invention is used for manufacturing an inductive circuit element as a module for use in another circuit rather than integrally created with a circuit. Either employment of the structure or method of the present invention yields similar advantages that include lower profile and fewer sources of “stray” inductance and capacitance.





FIG. 8

is a simplified side view of the inductive circuit element illustrated in

FIG. 3

showing a third alternate placement arrangement for magnetic core segments. In

FIG. 8

, an inductive circuit element


850


is arrayed in a base member


852


. Base member


852


is a single substrate having a top face


871


and a bottom face


873


.




Depressions


840


,


842


,


844


,


846


are established in top face


871


appropriately dimensioned to nestlingly receive magnetic core segments (e.g., magnetic core segments


60


,


64


; FIG.


3


). Depressions


840


,


842


,


844


,


846


partially extend into base member


852


from top face


871


. A separation distance d


1


is established between depressions


840


,


842


. Separation distance d


1


is preferably established at a dimension to permit magnetic flux coupling between magnetic core segments situated within depressions


840


,


842


. A separation distance d


2


is established between depressions


844


,


846


. Separation distance d


2


is preferably established at a dimension to permit magnetic flux coupling between magnetic core segments situated within depressions


844


,


846


.





FIG. 9

is a plan view of a representative circuit layout illustrating an alternate structure for fixing position of a core segment in a product. In

FIG. 9

, a product


900


includes a plurality of etched lands


902


,


904


,


906


,


908


on a substrate


910


. Lands


902


,


904


,


906


,


908


are preferably copper lands. Lands


902


,


904


,


906


,


908


extend substantially perpendicularly from substrate


910


a distance sufficient to establish a thickness of lands


902


,


904


,


906


,


908


(not shown in FIG.


9


). The thickness of lands


902


,


904


,


906


,


908


thus established are of sufficient dimension to form a fixture


912


for nestlingly fixing a core segment


914


against lateral movement in directions generally parallel with substrate


910


. Preferably the thickness of lands


902


,


904


,


906


,


908


is about one-half the thickness of core segment


914


, or greater. Through-holes


916


,


918


,


920


may be provided configured, for example, for solder-filling to contribute to establishing loops about core segment


914


.




It is to be understood that, while the detailed drawings and specific examples given describe preferred embodiments of the invention, they are for the purpose of illustration only, that the apparatus and method of the invention are not limited to the precise details and conditions disclosed and that various changes may be made therein without departing from the spirit of the invention which is defined by the following



Claims
  • 1. An apparatus for effecting inductive coupling with a ferromagnetic core structure; the apparatus comprising:(a) at least one substrate of a dielectric material; at least one selected substrate of said at least one substrate being configured with at least one fixture; each said at least one fixture being dimensioned for receiving a respective core segment; a core segment sets including at least two said core segments is received by said at least one fixture and separated by a volume of said dielectric material; said core segment sets being arranged for establishing magnetic flux coupling among said at least two core segments to establish said ferromagnetic core structure when said at least one substrate is in an assembled orientation with said ferromagnetic core structure and said at least one substrate arranged in a unitary structural relationship; (b) a plurality of electrically conductive circuit traces; said plurality of circuit traces being arrayed upon at least two predetermined surfaces of said at least one substrate; (c) a plurality of electrically conductive through-hole structures; said plurality of through-hole structures traversing said at least one selected substrate; said plurality of circuit traces and said plurality of through-hole structures cooperating to establish said inductive coupling when said at least one substrate is in said assembled orientation.
  • 2. An apparatus for effecting inductive coupling with a ferromagnetic core structure as recited in claim 1 wherein said at least one substrate is a plurality of substrates, and wherein each respective substrate of said plurality of substrates is substantially planar, and wherein said assembled orientation abuttingly situates said plurality of substrates substantially in parallel in said unitary structural relationship.
  • 3. An apparatus for effecting inductive coupling with a ferromagnetic core structure as recited in claim 1 wherein said inductive coupling establishes an inductor element including said ferromagnetic core structure.
  • 4. An apparatus for effecting inductive coupling with a ferromagnetic core structure as recited in claim 1 wherein said inductive coupling establishes a transformer element including said ferromagnetic core structure.
  • 5. An apparatus for effecting inductive coupling with a ferromagnetic core structure as recited in claim 1 wherein each said respective core segment is embodied in a pliable magnetic material.
  • 6. An apparatus for effecting inductive coupling with a ferromagnetic core structure as recited in claim 5 wherein said pliable magnetic material is a magnetically loaded paste material.
  • 7. An apparatus for effecting inductive coupling with a ferromagnetic core structure as recited in claim 5 wherein said pliable magnetic material is a magnetically loaded polymer composite sheet material.
  • 8. An apparatus for effecting inductive coupling with a ferromagnetic core structure as recited in claim 2 wherein said inductive coupling establishes an inductor element including said ferromagnetic core structure.
  • 9. An apparatus for effecting inductive coupling with a ferromagnetic core structure as recited in claim 2 wherein said inductive coupling establishes a transformer element including said ferromagnetic core structure.
  • 10. An apparatus for effecting inductive coupling with a ferromagnetic core structure as recited in claim 2 wherein each said respective core segment is embodied in a pliable magnetic material.
  • 11. An apparatus for effecting inductive coupling with a ferromagnetic core structure as recited in claim 10 wherein said pliable magnetic material is a magnetically loaded paste material.
  • 12. An apparatus for effecting inductive coupling with a ferromagnetic core structure as recited in claim 10 wherein said pliable magnetic material is a magnetically loaded polymer composite sheet material.
US Referenced Citations (3)
Number Name Date Kind
5430613 Hastings et al. Jul 1995 A
5781091 Krone et al. Jul 1998 A
5959846 Noguchi et al. Sep 1999 A
Foreign Referenced Citations (1)
Number Date Country
58-53807 Mar 1983 JP