Manufacture and use of planar embedded magnetics as discrete components and in integrated connectors

• US 20100295646A1
• Filed: 12/01/2009
• Published: 11/25/2010
• Est. Priority Date: 01/11/2007
• Status: Active Grant

• Current Assignee: PlanarMag, Inc. (TE Connectivity Limited)
• Original Assignee: PlanarMag, Inc. (TE Connectivity Limited)
• Inventors: Dalmia, Sidharth, Quilici, James E., Pham, And-Vu, Kubes, Steven R., Harrison, William Lee
• Granted Patent: US 8,203,418 B2
• Time in Patent Office: Days
• US Class Current: 336/192
• CPC Class Codes: H01F 17/0033 with the coil helically wound around a magnetic core
• CPC Class Codes: H01F 19/04 Transformers or mutual inductances suitable for handling frequencies considerably beyond the audio range resonant circuits H03H
• CPC Class Codes: H01F 30/16 Toroidal transformers
• CPC Class Codes: H01F 41/046 structurally combined with ferromagnetic material
• CPC Class Codes: H01R 13/6633 with inductive component, e.g. transformer
• CPC Class Codes: H01R 13/719 specially adapted for high frequency, e.g. with filters
• CPC Class Codes: H01R 24/64 for high frequency, e.g. RJ 45
• CPC Class Codes: H05K 1/0233 Filters, inductors or a magnetic substance
• CPC Class Codes: H05K 1/183 Components mounted in and supported by recessed areas of the printed circuit board
• CPC Class Codes: H05K 2201/086 for inductive purposes, e.g. printed inductor with ferrite core
• CPC Class Codes: H05K 2201/10189 Non-printed connector

Abstract

The current invention provides an integrated planar transformer and electronic component that includes at least one wideband planar transformer disposed in a planar substrate, where each wideband planar transformer includes a planar substrate in a fully-cured and rigid state, a ferrite material embedded in the planar substrate, where the ferrite material is enveloped in an elastic and non-conductive material, inter-wound conductors disposed around the embedded ferrite material, where top and bottom conductors are bonded by an insulating adhesive. The top and bottom conductors are connected in an inter-connected pattern by conductive vias disposed on each side of the ferrite material and span through the layers to the conductors. The planar transformer further includes at least one center tap connected to at least one inter-wound conductor. The integrated planar transformer and electronic component further includes at least one electronic component connected to at least one terminal of the wide-band planar transformer.

Claims

1. A integrated planar transformer and electronic component, comprising:

a. at least one wideband planar transformer disposed in a planar substrate, wherein each said wideband planar transformer comprises;

i. a planar substrate, wherein said planar substrate is in a fully-cured and rigid state;

ii. a ferrite material, wherein said ferrite material is embedded in said fully-cured and rigid planar substrate, wherein said embedding comprises said ferrite material enveloped in an elastic and non-conductive material;

iii. inter-wound conductors disposed around said embedded ferrite material, wherein said inter-wound conductors comprise top conductors bonded by a first bonding layer to a top surface of said fully-cured and rigid substrate and bottom conductors bonded by a second bonding layer to a bottom surface of said fully-cured and rigid substrate, wherein said bonding layers comprise an insulating adhesive, wherein said top and bottom conductors are connected in an inter-connected pattern by conductive vias disposed on each side of said ferrite material, wherein said conductive vias span through said bonding layers and through said fully-cured and rigid planar substrate forming said inter-wound conductors;

iv. at least one center tap connected to at least one said inter-wound conductor; and

b. at least one electronic component, wherein said electronic component is connected to at least one terminal of said wide-band planar transformer.

2. The integrated planar transformer and electronic component of claim 1, wherein said planar substrate is selected from the group consisting of FR4, thermoset and thermoplastic.

3. The integrated planar transformer and electronic component of claim 1, wherein adjacent said top conductors and said bottom conductors are disposed to conform to parallel and predetermined spacing there between and said adjacent top conductors and said bottom conductors are disposed to maximize a number of said windings around said embedded ferrite material to lower a winding parasitic inductance and leakage inductance.

4. The integrated planar transformer and electronic component of claim 3, wherein said spacing between said top conductors is in a range of 10 μ

m to 500 μ

m.

5. The integrated planar transformer and electronic component of claim 1, wherein said conductive layers are laminated to said planar substrate using laminate materials selected from the group consisting of a flexible epoxy, high temperature thermoplastics, and high flow ceramic filled hydrocarbon.

6. The integrated planar transformer and electronic component of claim 1, wherein said center taps are impedance-matched to 50% of a differential impedance.

7. The integrated planar transformer and electronic component of claim 1, wherein said ferrite material has a shape selected from the group consisting of annulus, toroid, U-shape, E-shape and bar.

8. The integrated planar transformer and electronic component of claim 7, wherein a center of said annulus shape ferrite material or said toroid shape ferrite material comprise a dimensionally stable potting compound disposed therein.

9. The integrated planar transformer and electronic component of claim 7, wherein a center of said annulus shape ferrite material or said toroid shape ferrite material comprise a thermoplastic element disposed therein, wherein said thermoplastic element comprises material properties that match material properties of said planar substrate and a shape that match a shape of said annulus center or a shape of said toroid center.

10. The integrated planar transformer and electronic component of claim 1, wherein a breakdown material is disposed across at least two terminals of said wideband planar transformer, wherein said breakdown material actuates when exposed to a potential in a range of 500V rms to 10,000V rms.

11. The integrated planar transformer and electronic component of claim 1, wherein all external surfaces of said integrated planar transformer are coated with an insulating layer, wherein at least one terminal of said integrated planar transformer is exposed.

12. The integrated planar transformer and electronic component of claim 1, wherein connections between said wideband planar transformer and said electronic component comprises at least one electrically conductive pin disposed through at least one hole in said substrate, wherein said at least one electrically conductive pin is linear or angled.

13. The integrated planar transformer and electronic component of claim 1, wherein said top conductors comprise a teardrop-shape, wherein a narrow end of said teardrop-shape is connected to an inner conductive element disposed in a center of an annulus-shaped or toroid-shaped of said ferrite material and a broad end of said teardrop-shape is connected to an outer conductive element disposed around an outside of said annulus-shaped or toroid-shaped said ferrite material.

14. The integrated planar transformer and electronic component of claim 13, wherein transformer inductors are coupled with a coupling coefficient between 0 to 1, wherein said coupling is according to i) a spacing between said conductive elements, or ii) a spacing between said teardrop-shape conductors, or iii) an open span in said annulus or said toroid ferrite, or iv) according to a ratio of primary and secondary said interwindings, or i), ii), iii) and iv), wherein said open span comprises an air gap, wherein said air gap may comprise at least one ground via.

15. The integrated planar transformer and electronic component of claim 1, wherein said electronic component comprises any connector requiring isolation or electromagnetic functionality.

16. The integrated planar transformer and electronic component of claim 15, wherein said connector comprises at least one electrical contact connected to at least one terminal of said planar transformer.

17. The integrated planar transformer and electronic component of claim 1, wherein said at least one wideband planar transformer comprises an array of said wideband planar transformers.

18. The integrated planar transformer and electronic component of claim 1, wherein said at least one electronic component comprises an array of said connectors.

19. The integrated planar transformer and electronic component of claim 1, wherein said at least one electronic component comprises an array of said PCB'"'"'s.

20. The integrated planar transformer and electronic component of claim 1, wherein a bottom surface of said integrated planar transformer and electronic component comprises solder pads.

21. The integrated planar transformer and electronic component of claim 1, wherein thermal conduits are disposed to extract heat generated at said inter-wound conductors.

22. The integrated planar transformer and electronic component of claim 21, wherein said thermal conduits are selected from the group consisting of heat conductive metal plated vias, at least one heat conductive metal layer, additional heat conductive metal disposed on at least one signal trace, at least one heat conductive tab disposed at an edge of said integrated planar transformer device, and a heat conductive material around said edge of said integrated planar transformer and electronic component.

23. The integrated planar transformer and electronic component of claim 1, wherein said at least one center tap is disposed on top of said wideband planar transformer.

24. The integrated planar transformer and electronic component of claim 1, wherein said electronic component is disposed on top of said planar substrate to minimize a distance there between to providing a desired match for a center tap current.

25. The integrated planar transformer and electronic component of claim 1, wherein said wideband planar transformer further comprises i) at least one common mode choke, wherein each said common mode choke provides signal shaping and condition, or ii) M-circuits, or i) and ii), wherein said M-Circuits are electrical circuitry supporting functionalities of said embedded wideband planar transformer for specific functions and applications.

26. The integrated planar transformer and electronic component of claim 25, wherein said functionalities supported by said M-Circuits are selected from the group consisting of filter functions, cross talk cancellation functions, high voltage suppression, EMI suppression, digital controls, LED controls, Balun, and power management functionality.

27. The integrated planar transformer and electronic component of claim 1, wherein said integration comprises stacking, wherein said stacking comprises at least a first said wideband planar transformer and a first choke on top of a second said wideband planar transformer and a second said choke and a filter and impedance matching element on top of said first wideband planar transformer and said first choke, wherein a number of said wideband planar transformers in said stack is according to a desired application.

28. The integrated planar transformer and electronic component of claim 1, wherein said integration comprises stacking, wherein said stacking comprises a choke on top of a filter, wherein said filter is disposed on top of an impedance matching element and said impedance matching element is disposed on said wideband planar transformer.

29. The integrated planar transformer and electronic component of claim 1, wherein said elastic and non-conductive material comprises at least one filler, wherein said elastic and non-conductive material with said filler have a coefficient of thermal expansion up to a coefficient of thermal expansion of said planar substrate.

30. The integrated planar transformer and electronic component of claim 1, wherein drill holes are provided in said substrate, wherein a thermal expansion of said integrated planar transformer and electronic component is controlled by said drilled holes.