Widebody Coil Isolators

• US 20100259909A1
• Filed: 03/31/2010
• Published: 10/14/2010
• 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: Ho, Dominique, Fouquet, Julie
• Granted Patent: US 8,427,844 B2
• Time in Patent Office: Days
• US Class Current: 361/767
• 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 2224/05599 Material
• CPC Class Codes: H01L 2224/32245 the item being metallic
• CPC Class Codes: H01L 2224/45099 Material
• CPC Class Codes: H01L 2224/48091 Arched
• 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 2224/48227 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/48465 the other connecting portion not on the bonding area being a wedge bond, i.e. ball-to-wedge, regular stitch
• CPC Class Codes: H01L 2224/48471 the other connecting portion not on the bonding area being a ball bond, i.e. wedge-to-ball, reverse stitch
• CPC Class Codes: H01L 2224/4903 Connectors having different sizes, e.g. different diameters
• CPC Class Codes: H01L 2224/49107 on the semiconductor or solid-state body
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 23/295 containing a filler H01L23/296 takes precedence
• CPC Class Codes: H01L 23/3107 : the device being completely enclosed
• CPC Class Codes: H01L 23/48 : Arrangements for conducting electric current to or from the solid state body in operation, e.g. leads, terminal arrangements ; Selection of materials therefor
• CPC Class Codes: H01L 23/495 : Lead-frames or other flat leads H01L23/498 takes precedence; lead frame interconnections between components H01L23/52
• CPC Class Codes: H01L 23/49537 : Plurality of lead frames mounted in one device
• CPC Class Codes: H01L 23/49575 : Assemblies of semiconductor devices on lead frames
• CPC Class Codes: H01L 24/48 : of an individual wire connector
• CPC Class Codes: H01L 24/49 : of a plurality of wire connectors
• 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 2924/00012 : Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• 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 2924/01005 : Boron [B]
• CPC Class Codes: H01L 2924/01006 : Carbon [C]
• CPC Class Codes: H01L 2924/01013 : Aluminum [Al]
• CPC Class Codes: H01L 2924/01014 : Silicon [Si]
• CPC Class Codes: H01L 2924/01018 : Argon [Ar]
• CPC Class Codes: H01L 2924/01031 : Gallium [Ga]
• CPC Class Codes: H01L 2924/01033 : Arsenic [As]
• CPC Class Codes: H01L 2924/0106 : Neodymium [Nd]
• CPC Class Codes: H01L 2924/01064 : Gadolinium [Gd]
• CPC Class Codes: H01L 2924/01074 : Tungsten [W]
• CPC Class Codes: H01L 2924/01076 : Osmium [Os]
• CPC Class Codes: H01L 2924/01082 : Lead [Pb]
• CPC Class Codes: H01L 2924/09701 : Low temperature co-fired ceramic [LTCC]
• CPC Class Codes: H01L 2924/10155 : being other than a cuboid
• CPC Class Codes: H01L 2924/10253 : Silicon [Si]
• CPC Class Codes: H01L 2924/1204 : Optical Diode
• CPC Class Codes: H01L 2924/12043 : Photo diode
• CPC Class Codes: H01L 2924/14 : Integrated circuits
• CPC Class Codes: H01L 2924/181 : Encapsulation
• CPC Class Codes: H01L 2924/30107 : Inductance
• CPC Class Codes: H03H 7/46 : Networks for connecting several sources or loads, working on different frequencies or frequency bands, to a common load or source for use in multiplex transmission systems H04J1/00
• CPC Class Codes: H03H 7/52 : One-way transmission networks, i.e. unilines
• CPC Class Codes: H04B 5/0031 : for data transfer
• CPC Class Codes: H04B 5/0037 : for power transfer
• CPC Class Codes: H04B 5/005 : for isolation purposes
• CPC Class Codes: H04B 5/0093 : with one coil at each side, e.g. with primary and secondary coils
• CPC Class Codes: H04B 5/266 : One coil at each side, e.g. with primary and secondary coils
• CPC Class Codes: H04B 5/72 : for local intradevice communication
• CPC Class Codes: H04B 5/75 : for isolation purposes
• CPC Class Codes: H04B 5/79 : for data transfer in combination with power transfer
• 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 widebody coil isolators containing multiple coil transducers, where integrated circuits are not stacked vertically over the coil transducers. The disclosed coil isolators provide high voltage isolation and high voltage breakdown performance characteristics in small packages that provide a high degree of functionality at a low price.

Claims

1. A coil isolator, comprising:

a coil transducer having opposing first and second ends and comprising a dielectric barrier having opposing first and second sides, the dielectric barrier comprising an electrically insulating, non-metallic, non-semiconductor, low-dielectric-loss material, a first electrically conductive transmitter coil disposed near or on the first side, first leads extending between the first coil and wire bond pads corresponding thereto, and a second electrically conductive receiver coil disposed near or on the second side, second leads extending between the second coil and wire bond pads corresponding thereto, the dielectric barrier being disposed between the first and second coils;

a first lead frame comprising a first IC die pad, and

a second lead frame comprising a second IC die pad;

wherein the first and second lead frames are separated by a gap, the first IC pad has a first IC attached thereto, the second IC pad has a second IC attached thereto, the coil transducer extends horizontally across the gap between the first and second lead frames and the first and second ends extend onto the first and second lead frames, no portions of the first and second lead frames are disposed vertically over or beneath any portions of the first and second coils, the coil wirebond pads are disposed vertically over or beneath the first and second lead frames, respectively, and the gap is filled substantially with at least one electrically non-conductive material having a voltage breakdown exceeding about 2,000 volts RMS.

2. The coil isolator of claim 1, wherein the coil transducer is a flex circuit.

3. The coil isolator of claim 1, wherein the first IC comprises a transmitter circuit and has transmitter output terminals, the transmitter output terminals being operably connected to the first coil through the wire bond pads corresponding thereto.

4. The coil isolator of claim 1, wherein the second IC comprises a receiver circuit and has receiver input terminals, the receiver input terminals being operably connected to the second coil through the wire bond pads corresponding thereto.

5. The coil isolator of claim 1, wherein 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 dielectric barrier

6. The coil isolator of claim 1, wherein the first and second coils, in combination, have at least five turns, at least eight turns, at least ten turns, or at least twenty turns.

7. The coil isolator of claim 1, wherein the dielectric barrier comprises 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, plastic, a polymer or combination of polymers containing ceramic beads or particles, or ceramic/polymer blends, mixes and combinations.

8. The coil isolator of claim 1, wherein a breakdown voltage between the coil transducer and the first IC or second IC across the gap 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.

9. The coil isolator of claim 1, wherein the coil transducer and at least portions of the first and second lead frames are encapsulated with a molding material comprising silica-loaded epoxy.

10. The coil isolator of claim 1, wherein wire bond pads for coils of the coil transducer are located on both sides of a major axis of the coil transducer.

11. A coil isolator, comprising:

a coil transducer having opposing first and second ends and comprising a dielectric barrier having opposing first and second sides, the dielectric barrier comprising an electrically insulating, non-metallic, non-semiconductor, low-dielectric-loss material, a first electrically conductive transmitter coil disposed near or on the first side, first leads extending between the first coil and wire bond pads corresponding thereto, and a second electrically conductive receiver coil disposed near or on the second side, second leads extending between the second coil and wire bond pads corresponding thereto, the dielectric barrier being disposed between the first and second coils;

a substrate having at least one aperture disposed therethrough, the at least one aperture having at least one periphery;

a first lead frame comprising an integrated circuit (IC) die pad, the first lead frame being located near the substrate but separated therefrom by a first gap, the first IC pad having a first IC attached thereto;

a second lead frame comprising a second IC die pad, the second lead frame being located near the substrate but separated therefrom by a second gap, the second IC pad having a second IC attached thereto,

wherein the coil transducer extends horizontally across the aperture and the first and second ends extend at least partially beyond the periphery and onto or beneath non-aperture portions of the substrate, the non-aperture portions of the substrate are not disposed vertically over or beneath any portions of the first and second coils, the coil wirebond pads are disposed vertically over or beneath non-aperture portions of the substrate, and the first and second gaps are filled substantially with at least one electrically non-conductive material having a voltage breakdown exceeding about 2,000 volts RMS.

12. The coil isolator of claim 11, wherein the coil transducer is a flex circuit.

13. The coil isolator of claim 11, wherein the first IC comprises a transmitter circuit and has transmitter output terminals, the transmitter output terminals being operably connected to the first coil through the wire bond pads corresponding thereto.

14. The coil isolator of claim 11, wherein the second IC comprises a receiver circuit and has receiver input terminals, the receiver input terminals being operably connected to the second coil through the wire bond pads corresponding thereto.

15. The coil isolator of claim 11, wherein 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 dielectric barrier.

16. The coil isolator of claim 11, wherein the first and second coils, in combination, have at least five turns, at least eight turns, at least ten turns, or at least twenty turns.

17. The coil isolator of claim 11, wherein the dielectric barrier comprises 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, or plastic.

18. The coil isolator of claim 11, wherein a breakdown voltage between the coil transducer and the first IC or second IC across the gap 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.

19. The coil isolator of claim 14, wherein the coil transducer and at least portions of the first and second lead frames are encapsulated with a molding material comprising silica-loaded epoxy.

20. The coil isolator of claim 14, wherein wire bond pads for coils of the coil transducer are located on both sides of a major axis of the coil transducer.

21. A coil isolator, comprising:

a coil transducer having opposing first and second ends and comprising a dielectric barrier having opposing first and second sides, the dielectric barrier comprising an electrically insulating, non-metallic, non-semiconductor, low-dielectric-loss material, a first electrically conductive transmitter coil disposed near or on the first side, first leads extending between the first coil and wire bond pads corresponding thereto, and a second electrically conductive receiver coil disposed near or on the second side, second leads extending between the second coil and wire bond pads corresponding thereto, the dielectric barrier being disposed between the first and second coils;

a first lead frame comprising an integrated circuit (IC) die pad, the first IC pad having a first IC attached thereto;

a second lead frame comprising a second IC die pad, the second lead frame being located near the first lead frame and separated therefrom by a gap, the second IC pad having a second IC attached thereto, the second lead frame having at least one aperture disposed therethrough, the aperture having at least one periphery;

wherein the coil transducer extends horizontally across the aperture and the first and second ends extend at least partially beyond the periphery and onto or beneath non-aperture portions of the second lead frame, the non-aperture portions of the second lead frame are not disposed vertically over or beneath any portions of the first and second coils, the coil wirebond pads are disposed vertically over or beneath non-aperture portions of the second lead frame, and the gap is filled substantially with at least one electrically non-conductive material having a voltage breakdown exceeding about 2,000 volts RMS.

22. The coil isolator of claim 21, wherein the coil transducer is a flex circuit.

23. The coil isolator of claim 21, wherein the first IC comprises a transmitter circuit and has transmitter output terminals, the transmitter output terminals being operably connected to the first coil through the wire bond pads corresponding thereto.

24. The coil isolator of claim 21, wherein the second IC comprises a receiver circuit and has receiver input terminals, the receiver input terminals being operably connected to the second coil through the wire bond pads corresponding thereto.

25. The coil isolator of claim 21, wherein 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 dielectric barrier.

26. The coil isolator of claim 21, wherein the first and second coils, in combination, have at least five turns, at least eight turns, at least ten turns, or at least twenty turns.

27. The coil isolator of claim 21, wherein the dielectric barrier comprises 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, or plastic.

28. The coil isolator of claim 21, wherein a breakdown voltage between the coil transducer and the first IC across the first gap, or between the coil transducer and the second IC across the second gap, 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.

29. The coil isolator of claim 21, wherein the coil transducer and at least portions of the first and second lead frames are encapsulated with a molding material comprising silica-loaded epoxy.

30. The coil isolator of claim 21, wherein wire bond pads for coils of the coil transducer are located on both sides of a major axis of the coil transducer.

31. A method of making a coil isolator, comprising:

providing a coil transducer having opposing first and second ends and comprising a dielectric barrier having opposing first and second sides, the dielectric barrier comprising an electrically insulating, non-metallic, non-semiconductor, low-dielectric-loss material, a first electrically conductive transmitter coil disposed near or on the first side, first leads extending between the first coil and wire bond pads corresponding thereto, and a second electrically conductive receiver coil disposed near or on the second side, second leads extending between the second coil and wire bond pads corresponding thereto, the dielectric barrier being disposed between the first and second coils;

providing a first integrated circuit (IC), a second IC, and first and second lead frames, the first lead frame including a first IC die pad, the second lead frame including a second IC pad;

placing the first and second lead frames near one another such that the first and second lead frames are separated by a gap;

attaching the first and second ICs to the first and second IC pads, respectively;

attaching the coil transducer to the first and second lead frames such that the coil transducer extends horizontally between the first and second lead frames and the first and second ends extend onto or beneath at least portions of the first and second lead frames, no portions of the first and second lead frames are disposed vertically over or beneath any portions of the first and second coils, and the wire bond pads of the first and second coils are disposed vertically over or beneath the first and second lead frames, respectively, and

filling the gap substantially with at least one electrically non-conductive material having a voltage breakdown exceeding about 2,000 volts RMS.

32. The method of claim 31, further comprising encapsulating the coil transducer and at least portions of the first and second lead frames with a molding material comprising silica-loaded epoxy.

33. A method of making a coil isolator, comprising:

providing a coil transducer having opposing first and second ends and comprising a dielectric barrier having opposing first and second sides, the dielectric barrier comprising an electrically insulating, non-metallic, non-semiconductor, low-dielectric-loss material, a first electrically conductive transmitter coil disposed near or on the first side, first leads extending between the first coil and wire bond pads corresponding thereto, and a second electrically conductive receiver coil disposed near or on the second side, second leads extending between the second coil and wire bond pads corresponding thereto, the dielectric barrier being disposed between the first and second coils;

providing a substrate having at least one aperture disposed therethrough, the aperture having at least one periphery;

providing a first integrated circuit (IC) and a first lead frame comprising a first IC die pad;

providing a second IC and a second lead frame comprising a second IC die pad;

attaching the first IC to the first IC pad and the second IC to the second IC pad;

attaching the coil transducer to the substrate such that the coil transducer extends horizontally across the aperture and at least portions of the first and second ends extend beyond the periphery and onto or beneath non-aperture portions of the substrate, non-aperture portions of the substrate are not disposed vertically over or beneath any portions of the first and second coils, and the wire bond pads of the first and second coils are disposed vertically over or beneath non-aperture portions of the substrate;

placing the first lead frame near the substrate such that the first lead frame and the substrate are separated by a first gap;

placing the second lead frame near the substrate such that the second lead frame and the substrate are separated by a second gap, and

filling the first and second gaps substantially with at least one electrically non-conductive material having a voltage breakdown exceeding about 2,000 volts RMS.

34. The method of claim 33, further comprising encapsulating the coil transducer, at least portions of the substrate, and at least portions of the first and second lead frames with a molding material comprising silica-loaded epoxy.

35. A method of making a coil isolator, comprising:

providing a coil transducer having opposing first and second ends and comprising a dielectric barrier having opposing first and second sides, the dielectric barrier comprising an electrically insulating, non-metallic, non-semiconductor, low-dielectric-loss material, a first electrically conductive transmitter coil disposed near or on the first side, first leads extending between the first coil and wire bond pads corresponding thereto, and a second electrically conductive receiver coil disposed near or on the second side, second leads extending between the second coil and wire bond pads corresponding thereto, the dielectric barrier being disposed between the first and second coils;

providing a first integrated circuit (IC) and a first lead frame comprising a first IC die pad;

providing a second IC and a second lead frame comprising a second IC die pad having at least one aperture disposed therethrough, the aperture having at least one periphery;

attaching the first IC to the first IC pad and the second IC to the second IC die pad;

attaching the coil transducer to the second lead frame such that the coil transducer extends horizontally across the aperture and at least portions of the first and second ends extend beyond the periphery and onto or beneath non-aperture portions of the second lead frame, non-aperture portions of the second lead frame are not disposed vertically over or beneath any portions of the first and second coils, and the wire bond pads of the first and second coils are disposed vertically over or beneath non-aperture portions of the second lead frame;

placing the first lead frame near the second lead frame such that the first lead frame and the second lead frame are separated by a gap, and

filling the gap substantially with at least one electrically non-conductive material having a voltage breakdown exceeding about 2,000 volts RMS.

36. The method of claim 35, further comprising encapsulating the coil transducer, at least portions of the substrate, and at least portions of the first and second lead frames with a molding material comprising silica-loaded epoxy.