High Voltage Hold-Off Coil Transducer

• US 20090243782A1
• Filed: 02/12/2009
• Published: 10/01/2009
• Est. Priority Date: 08/28/2006
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Avago Technologies ECBU IP Singapore Pte Limited (Broadcom, Inc.)
• Inventors: Webster, Clark F., Fouquet, Julie E., Trott, Gary R.
• Granted Patent: US 9,105,391 B2
• Time in Patent Office: Days
• US Class Current: 336/200
• CPC Class Codes: H01F 17/0006 Printed inductances printed coils for dynamo-electric machines H02K3/26; printed circuits H05K
• CPC Class Codes: H01F 17/0013 with stacked layers
• 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 19/08 Transformers having magnetic bias, e.g. for handling pulses
• CPC Class Codes: H01F 2019/085 Transformer for galvanic isolation
• CPC Class Codes: H01F 2027/2809 on stacked layers
• CPC Class Codes: H01F 27/2804 Printed windings
• CPC Class Codes: H01F 27/324 Insulation between coil and core, between different winding sections, around the coil; Other insulation structures
• CPC Class Codes: H01F 27/40 Structural association with built-in electric component, e.g. fuse
• CPC Class Codes: H01L 2224/48137 the bodies being arranged next to each other, e.g. on a common substrate
• CPC Class Codes: H01L 2224/48195 the item being a discrete passive component
• CPC Class Codes: H01L 2224/49175 Parallel arrangements
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/3025 Electromagnetic shielding
• CPC Class Codes: H03F 2203/45008 the addition of two signals being made by a resistor addition circuit for producing the common mode signal
• CPC Class Codes: H03F 2203/45101 Control of the DC level being present
• CPC Class Codes: H03F 2203/45586 the IC comprising offset generating means
• CPC Class Codes: H03F 3/45192 Folded cascode stages
• CPC Class Codes: H03F 3/45475 using IC blocks as the active amplifying circuit
• CPC Class Codes: H03H 7/52 One-way transmission networks, i.e. unilines
• CPC Class Codes: H04L 25/0266 : Arrangements for providing Galvanic isolation, e.g. by means of magnetic or capacitive coupling
• CPC Class Codes: Y10T 29/4902 : Electromagnet, transformer or inductor

Abstract

Disclosed herein are various embodiments of coil transducers configured to provide high voltage isolation and high voltage breakdown performance characteristics in small packages. A coil transducer is provided through and across which data or power signals may be transmitted and received by primary and secondary coils disposed on opposing sides thereof without high voltage breakdowns occurring therebetween. A central core layer separates the transmitting and receiving coils, and has no vias disposed therethrough. At least portions of the coil transducer are formed of an electrically insulating, non-metallic, non-semiconductor, low dielectric loss material.

Claims

1. A coil transducer, comprising:

a generally planar dielectric barrier and electrically insulating core structure having upper and lower surfaces and comprising a central core layer, an upper core layer disposed above the central core layer and a lower core layer disposed below the central core layer, each of the central, upper and lower core layers comprising an electrically insulating, non-metallic, non-semiconductor, low-dielectric-loss material;

a first electrically conductive coil disposed above the core layer, and a second electrically conductive coil disposed below the core layer;

wherein the core layer has no vias disposed therethrough or therein and the first and second coils are spatially arranged and configured respecting one another such that at least one of power and data signals may be transmitted by the first coil to the second coil across the core layer.

2. The coil transducer of claim 1, wherein the central core layer is solid and comprises polyimide.

3. The coil transducer of claim 1, wherein the upper and lower core layers comprise a polyimide-containing material comprising an adhesive.

4. The coil transducer of claim 3, further comprising an upper solid layer having first and second metallized layers disposed on or in upper and lower surfaces thereof to form at least portions of the first coil, the upper solid layer being disposed above the upper core layer, and a lower solid layer having third and fourth metallized layers disposed on or in upper and lower surfaces thereof to form at least portions of the second coil, the lower solid layer being disposed below the lower core layer.

5. The coil transducer of claim 4, wherein the upper core layer is in contact with at least portions of the second metallized layer and the lower core layer is in contact with at least portions of the third metallized layer.

6. The coil transducer of claim 5, further comprising an upper cover layer located above the upper solid layer and at least portions of the first metallized layer, the upper cover layer comprising an electrically insulating, non-metallic, non-semiconductor, low-dielectric-loss material, and a lower cover layer located below the lower solid layer and at least portions of the fourth metallized layer, the lower cover layer comprising an electrically insulating, non-metallic, non-semiconductor, low-dielectric-loss material.

7. The coil transducer of claim 6, wherein the lower cover layer is thicker than the upper cover layer, and the thickness of the lower cover layer is greater than or equal to about 1 mil.

8. The coil transducer of claim 6, wherein at least one of the upper cover layer and the lower cover layer comprises polyimide

9. The coil transducer of claim 1, further comprising an extension configured to have disposed thereon or therein at least one of a receiver circuit and a transmitter circuit.

10. The coil transducer of claim 9, wherein the extension further comprises at least one metallized ground pad disposed thereon and operably connected to an external ground.

11. The coil transducer of claim 1, wherein a portion of the core structure has been removed to permit an electrical connection to be established through the structure to the second coil.

12. The coil transducer of claim 1, further comprising at least first and second busbars electrically connected to the first and second coils, respectively.

13. The coil transducer of claim 1, wherein the first busbar is configured to extend from the first coil to a first face of the coil transducer, and the second busbar is configured to extend from the second coil to a second face of the coil transducer.

14. The coil transducer of claim 1, wherein the core structure is configured to impart structural rigidity and mechanical strength to the coil transducer.

15. The coil transducer of claim 1, wherein at least one of the layers in the core structure further comprises one or more of an adhesive, polyimide, polyimide resin, sticky polyimide, polyimide film, a polymer, acrylic, epoxy, an epoxy modifier, an epoxy resin, a polymer, a plastic, a thermoset plastic, a flex circuit material, fiberglass, glass, ceramic, an organic material, a printed circuit board material, PTFE and glass, PTFE and ceramic, glass and ceramic, an organic material, and a combination of an organic filler and an inorganic solid.

16. The coil transducer of claim 1, wherein a breakdown voltage between the first coil and the second coil exceeds about 2,000 volts RMS when applied over a time period of about one minute, exceeds about 2,000 volts RMS when applied over a time period of about six minutes, or exceeds about 2,000 volts RMS when applied over a time period of 24 hours.

17. The coil transducer of claim 1, wherein a breakdown voltage between the first coil and the second coil exceeds about 5,000 volts RMS when applied over a time period of about one minute, exceeds about 5,000 volts RMS when applied over a time period of about six minutes, or exceeds about 5,000 volts RMS when applied over a time period of 24 hours.

18. The coil transducer of claim 1, wherein the core structure has a thickness between upper and lower surfaces thereof ranging between about 1 mil and about 10 mils, between about 1 mil and about 8 mils, or between about 2 mils and about 5 mils.

19. The coil transducer of claim 1, wherein the core layer has a thickness ranging between about 1 mil and about 7 mils.

20. The coil transducer of claim 1, wherein at least one of an input lead frame and an output lead frame is connected to the coil transducer.

21. The coil transducer of claim 20, wherein electrically conductive portions of the lead frames are configured not to extend beneath the dielectric barrier and electrically insulating structure to locations directly beneath the first or second coils.

22. The coil transducer of claim 20, further comprising a moldable electrically insulating material encapsulating at least portions of the coil transducer and the input and output lead frames.

23. The coil transducer of claim 1, wherein the coil transducer is configured to operate as one of a data transfer device and a power transfer device.

24. The coil transducer of claim 1, wherein the first coil is operably connected to a transmitter circuit and the second coil is operably connected to a receiver circuit.

25. The coil transducer of claim 1, wherein at least one of the first coil and the second coil comprises at least one of gold, nickel, silver, copper, tungsten, tin, and aluminum, or alloys or combinations of any of the foregoing metals.

26. The coil transducer of claim 1, wherein all first portions thereof electrically connected to the first coil are, in any horizontal direction along one or more interfaces disposed between adjoining layers, a minimum of at least 0.4 mm away from all second portions thereof electrically connected to the second coil.

27. The coil transducer of claim 1, wherein the core layer has a dielectric loss tangent at room temperature that is less than or equal to 0.05.

28. A method of making a coil transducer, comprising:

forming a generally planar dielectric barrier and electrically insulating core structure having upper and lower surfaces and comprising a central core layer, an upper core layer disposed above the central core layer, and a lower core layer disposed below the central core layer, each of the central, upper and lower core layers comprising an electrically insulating, non-metallic, non-semiconductor, low-dielectric-loss material;

providing a first electrical conductor forming a first coil, the first coil being located above the core layer;

providing a second electrical conductor forming a second coil, the second coil being located below the core layer, and

configuring the first coil, the second coil and the core layer in respect of one another such that the first coil is separated from the second coil by the core layer, the first and second coils are spatially arranged and configured respecting one another such that at least one of power and data signals may be transmitted by the first coil to the second coil across the core layer, and the core layer has no vias disposed therethrough or therein.

29. The method of claim 28, further comprising providing an upper solid layer having first and second metallized layers disposed on or in upper and lower surfaces thereof to form at least portions of the first coil, the upper solid layer being configured to be disposed above the upper core layer, and providing a lower solid layer having third and fourth metallized layers disposed on or in upper and lower surfaces thereof to form at least portions of the second coil, the lower solid layer being configured to be disposed below the lower core layer.

30. The method of claim 29, further comprising stacking the core structure, the upper solid layer, and the lower solid layer operably in respect of one another to form a stacked transducer assembly, placing the stacked transducer assembly in a vacuum container, and drawing a vacuum on the container.

31. The method of claim 30, further comprising drawing a vacuum exceeding about 27 inches of mercury on the vacuum container and the stacked transducer assembly.

32. The method of claim 31, further comprising applying a pressure ranging between about 300 psi and about 400 psi to the stacked transducer assembly.

33. The method of claim 31, further comprising heating the stacked transducer assembly to a temperature ranging between about 330 degrees F. and about 390 degrees F.

34. The method of claim 33, further comprising continuing to heat the stacked coil transducer assembly for a period of time sufficient to melt or crosslink any adhesive included in the assembly.

35. The method of claim 29, further comprising providing one or more of an adhesive, polyimide, a polyimide-containing material comprising an adhesive, polyimide resin, sticky polyimide, polyimide film, a polymer, acrylic, epoxy, an epoxy modifier, an epoxy resin, a polymer, a plastic, a thermoset plastic, a flex circuit material, fiberglass, glass, ceramic, an organic material, a printed circuit board material, PTFE and glass, PTFE and ceramic, glass and ceramic, an organic material, and a combination of an organic filler and an inorganic solid to form at least one of the layers.

36. The method of claim 29, further comprising providing solid polyimide as the central core layer.

37. The method of claim 29, further comprising providing a polyimide-containing material comprising an adhesive for at least one of the upper core layer and the lower core layer.

38. The method of claim 29, further comprising placing an upper cover layer above the upper solid layer and at least portions of the first metallized layer, the upper cover layer comprising an electrically insulating, non-metallic, non-semiconductor, low-dielectric-loss material, and placing a lower cover layer below the lower solid layer and at least portions of the fourth metallized layer, the lower cover layer comprising an electrically insulating, non-metallic, non-semiconductor, low-dielectric-loss material.

39. The method of claim 29, further comprising providing at least first and second busbars and electrically connecting such busbars to the first and second coils, respectively.

40. The method of claim 39, further comprising configuring the first busbar to extend from the first coil to a first face of the coil transducer, and configuring the second busbar to extend from the second coil to a second face of the coil transducer.

41. The method of claim 29, further comprising locating, in any horizontal direction along one or more interfaces disposed between adjoining layers, all first portions of the coil transducer that are electrically connected to the first coil a minimum of at least 0.4 mm away from all second portions of the coil transducer that are electrically connected to the second coil.