Coil transducer with reduced arcing and improved high voltage breakdown performance characteristics

• US 7,852,186 B2
• Filed: 03/31/2008
• Issued: 12/14/2010
• Est. Priority Date: 08/28/2006
• Status: Expired due to Fees

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Avago Technologies ECBU IP Singapore Pte Limited (Broadcom, Inc.)
• Inventors: Fouquet, Julie E., Trott, Gary R.
• Primary Examiner(s): Enad; Elvin G
• Assistant Examiner(s): LIAN, MANG TIN BIK
• Application Number:
  US12/059,747
• Publication Number:
  US 20080180206A1
• Time in Patent Office: 988 Days
• Field of Search: None
• 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 19/08 Transformers having magnetic bias, e.g. for handling pulses
• CPC Class Codes: H01F 2019/085 Transformer for galvanic isolation
• CPC Class Codes: H01F 27/2804 Printed windings
• CPC Class Codes: H01F 27/40 Structural association with built-in electric component, e.g. fuse
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/19107 off-chip wires
• CPC Class Codes: H03H 7/52 One-way transmission networks, i.e. unilines

Abstract

Disclosed herein are various embodiments of coil transducers and galvanic isolators configured to provide high voltage isolation and high voltage breakdown performance characteristics in small packages. A coil transducer is provided 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. At least portions of the coil transducer are formed of an electrically insulating, non-metallic, non-semiconductor, low dielectric loss material. The coil transducer may be formed in a small package using, by way of example, printed circuit board, CMOS-compatible and other fabrication and packaging processes.

Claims

1. A coil transducer, comprising:

a generally planar electrically insulating substrate comprising opposing first upper and first lower surfaces, the substrate forming a dielectric barrier and comprising an electrically insulating, non-metallic, non-semiconductor, low dielectric loss material, the substrate having no ferrite, magnetic, ferromagnetic, or electroconductive core, or core material, disposed therewithin or thereon;

a first electrically conductive coil comprising at least a first metalized layer located above the first upper surface of the substrate;

a second electrically conductive coil comprising at least a third metalized layer located beneath the first lower surface of the substrate;

at least a first metalized via electrically connected to the first coil and extending to or near a second upper surface of the coil transducer for electrical connection to a first contact disposed thereon or therein, and

at least a second metalized via electrically connected to the second coil and extending to or near a second lower surface of the coil transducer for electrical connection to a second contact disposed thereon or therein;

wherein the first and second coils are not connected electrically to one another and 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 vertically across the substrate, the first coil is separated from the second coil by a vertical distance exceeding about 1/1,000^th of an inch (1 mil), and a breakdown voltage between the first coil and the second coil exceeds about 1,000 volts RMS.

2. The coil transducer of claim 1, further comprising an electrical conductor formed in a second metalized layer disposed within, upon or near the substrate, the electrical conductor and second layer being disposed above the first coil and the first metalized layer, the first coil and the electrical conductor being electrically connected to one another and to the first via.

3. The coil transducer of claim 1, further comprising an electrical conductor formed in a fourth metalized layer disposed within, upon or near the substrate, the electrical conductor and fourth layer being disposed below the second coil and the third metalized layer, the electrical conductor and the second coil being electrically connected to one another and to the second via.

4. The coil transducer of claim 1, wherein the substrate is configured to impart substantial structural rigidity and strength to the coil transducer.

5. The coil transducer of claim 1, wherein the substrate material further comprises at least one of fiberglass, glass, ceramic, polyimide, polyimide film, a polymer, an organic material, a flex circuit material, epoxy, epoxy resin, a printed circuit board material, PTFE and glass, PTFE and ceramic, glass and ceramic, thermoset plastic, and plastic.

6. The coil transducer of claim 1, wherein the coil transducer comprises a plurality of layers in addition to the substrate, at least one of the layers comprising the low dielectric loss material.

7. The coil transducer of claim 1, wherein the 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.

8. The coil transducer of claim 1, wherein the 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.

9. The coil transducer of claim 1, wherein at least one of the coil transducer and the substrate has a thickness between upper and lower surfaces thereof ranging between about 0.5 mils and about 25 mils, between about 1 mil and about 25 mils, or between about 1.5 mils and about 25 mils.

10. The coil transducer of claim 1, further comprising at least one of an input lead frame and an output lead frame connected to the coil transducer such that electrically conductive portions of the first and second lead frames do not extend beneath the substrate to locations directly beneath the first or second coils.

11. The coil transducer of claim 1, further comprising an input lead frame and an output lead frame connected to the coil transducer such that the input lead frame is mechanically connected to a lower surface of the coil transducer and the output lead frame is mechanically connected to an upper surface of the coil transducer.

12. The coil transducer of claim 1, further comprising an input lead frame and an output lead frame connected to the coil transducer, and a moldable electrically insulating material encapsulating at least portions of the coil transducer and the input and output lead frames.

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

14. 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.

15. The coil transducer of claim 1, wherein at least one of the first metalized layer and the second metalized layer comprises at least one of gold, nickel, silver, copper, tungsten, tin, aluminum, and aluminum-copper.

16. The coil transducer of claim 1, wherein the coil transducer is fabricated on one of a printed circuit board and a flex circuit substrate.

17. A coil transducer, comprising:

a generally planar electrically insulating substrate comprising opposing first upper and first lower surfaces, the substrate forming a dielectric barrier and comprising an electrically insulating, non-metallic, non-semiconductor low-dielectric-loss material having a dielectric loss tangent at room temperature that is less than or equal to 0.05, the substrate having no ferrite, magnetic, ferromagnetic, or electroconductive core, or core material, disposed therewithin or thereon;

a first electrically conductive coil comprising at least a first metalized layer located above the first upper surface of the substrate;

a second electrically conductive coil comprising at least a third metalized layer located beneath the first lower surface of the substrate;

at least a first metalized via electrically connected to the first coil and extending to or near a second upper surface of the coil transducer for electrical connection to a first contact disposed thereon or therein, and

at least a second metalized via electrically connected to the second coil and extending to or near a second lower surface of the coil transducer for electrical connection to a second contact disposed thereon or therein;

wherein the first and second coils are not connected electrically to one another and 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 vertically across the substrate, the first metalized layer is separated from the third metalized layer by a vertical distance exceeding about 1/1,000^th of an inch (1 mil), and a breakdown voltage between the first coil and the second coil exceeds about 1,000 volts RMS.

18. The coil transducer of claim 17, further comprising an electrical conductor formed in a second metalized layer disposed within, upon or near the substrate, the electrical conductor and the second layer being disposed above the first coil and the first metalized layer, the first coil and the electrical conductor being electrically connected to one another and to the first via.

19. The coil transducer of claim 17, further comprising an electrical conductor formed in a fourth metalized layer disposed within, upon or near the substrate, the electrical conductor and fourth layer being disposed below the second coil and the third metalized layer, the second coil and the electrical conductor being electrically connected to one another and to the second via.

20. The coil transducer of claim 17, wherein the substrate is configured to impart substantial structural rigidity and strength to the coil transducer.

21. The coil transducer of claim 17, wherein the substrate material further comprises a material selected from the group consisting of one or more of fiberglass, glass, ceramic, polyimide, polyimide film, a polymer, an organic material, a flex circuit material, epoxy, epoxy resin, a printed circuit board material, PTFE and glass, PTFE and ceramic, glass and ceramic, thermoset plastic, and plastic.

22. The coil transducer of claim 17, wherein the coil transducer comprises a plurality of layers in addition to the substrate, at least one of the layers comprising the low dielectric loss material.

23. The coil transducer of claim 17, wherein the 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.

24. The coil transducer of claim 17, wherein the 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.

25. The coil transducer of claim 17, wherein at least one of the coil transducer and the substrate has a thickness between upper and lower surfaces thereof ranging between about 0.5 mils and about 25 mils, between about 1 mil and about 25 mils, or between about 1.5 mils and about 25 mils.

26. The coil transducer of claim 17, further comprising at least one of an input lead frame and an output lead frame connected to the coil transducer such that electrically conductive portions of the first or second lead frames do not extend beneath the substrate to locations directly beneath the first or second coils.

27. The coil transducer of claim 17, further comprising an input lead frame and an output lead frame connected to the coil transducer such that the input and output lead frames are both mechanically connected to a lower surface of the coil transducer.

28. The coil transducer of claim 17, wherein the coil transducer is configured to operate as one of a data transfer device and a power transfer device.

29. The coil transducer of claim 17, wherein the first coil is operably connected to a transmitter circuit and the second coil is operably connected to a receiver circuit.

30. The coil transducer of claim 17, wherein at least one of the first metalized layer, the second metalized layer, the first via, and the second via comprises at least one of gold, nickel silver, copper, tungsten, tin, aluminum, and aluminum-copper.

31. The coil transducer of claim 17, wherein the coil transducer is fabricated on one of a printed circuit board and a flex circuit substrate.