Inductive device including bond wires

• US 6,998,952 B2
• Filed: 12/05/2003
• Issued: 02/14/2006
• Est. Priority Date: 12/05/2003
• Status: Expired due to Term

• Current Assignee: NXP USA, Inc. (NXP Semiconductors NV)
• Original Assignee: Freescale Semiconductor, Inc. (NXP Semiconductors NV)
• Inventors: Harper, Peter R., Pelley, Perry H. III, Zhou, Yaping, Chopin, Sheila F., Tran, Tu-Anh, Woosley, Alan H., Downey, Susan H.
• Primary Examiner(s): MAI, ANH T
• Application Number:
  US10/729,531
• Publication Number:
  US 20050122198A1
• Time in Patent Office: 802 Days
• Field of Search: 336/223, 336/200, 336/232, 336/65, 336/192, 296/021, 296/06, 257/E21.503, 257/E21.508, 257/E21.068
• US Class Current: 336/200
• CPC Class Codes: H01F 17/0033 with the coil helically wound around a magnetic core
• CPC Class Codes: H01F 41/046 structurally combined with ferromagnetic material
• CPC Class Codes: H01L 2224/45015 being circular
• CPC Class Codes: H01L 2224/45124 Aluminium (Al) as principal constituent
• CPC Class Codes: H01L 2224/45144 Gold (Au) as principal constituent
• CPC Class Codes: H01L 2224/45147 Copper (Cu) as principal constituent
• CPC Class Codes: H01L 2224/4813 Connecting within a semiconductor or solid-state body, i.e. fly wire, bridge wire
• CPC Class Codes: H01L 23/5227 Inductive arrangements or effects of, or between, wiring layers other inductive arrangements H01L23/645
• CPC Class Codes: H01L 23/645 Inductive arrangements H01L23/647, H01L23/66 take precedence
• CPC Class Codes: H01L 24/45 of an individual wire connector
• CPC Class Codes: H01L 24/48 of an individual wire connector
• 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 2924/01079 Gold [Au]
• CPC Class Codes: H01L 2924/09701 Low temperature co-fired ceramic [LTCC]
• CPC Class Codes: H01L 2924/14 Integrated circuits
• CPC Class Codes: H01L 2924/207 Diameter ranges
• CPC Class Codes: H01L 2924/30107 Inductance
• CPC Class Codes: H01L 2924/3025 Electromagnetic shielding
• CPC Class Codes: Y10T 29/4902 Electromagnet, transformer or inductor

Abstract

An inductive device (105) is formed above a substrate (225) having a conductive coil formed around a core (109). The coil comprises segments formed from a first plurality of bond wires (113) and a second plurality of bond wires (111). The first plurality of bond wires (113) extends between the core (109) and the substrate (225). Each of the first plurality of bond wires is coupled to two of a plurality of wire bond pads (117, 116). The second plurality of bond wires (111) extends over the core (109) and is coupled between two of the plurality of wire bond pads (117, 119). A shield (141) includes a portion that is positioned between the core (109) and the substrate (225).

Claims

1. An inductive device, comprising:

a core coupled to a substrate; and

a conductive coil surrounding the core, the coil comprising segments formed from a first plurality of bond wires and a second plurality of bond wires, the first plurality of bond wires extending between the core and the substrate, each of the first plurality of bond wires coupled to two of a plurality of wire bond pads, and the second plurality of bond wires extending over due core and coupled between two of the plurality of wire bond pads, wherein the core is coupled to the substrate using epoxy, the first plurality of bond wires extending through the epoxy.

2. The inductive device of claim 1, wherein the core includes a magnetic material selected from a group consisting of a ferrite material and a ferromagnetic material.

3. The inductive device of claim 1, wherein the core is cylindrical in shape.

4. The inductive device of claim 1, wherein the core is toroidal in shape.

5. The inductive device of claim 1, wherein the substrate is made of a silicon material.

6. The inductive device of claim 1 wherein the substrate is made of a semiconductor material.

7. The inductive device of claim 1 wherein the substrate is characterized as a lead frame.

8. The inductive device of claim 1, farther comprising a standoff for supporting the core a predetermined distance above a surface.

9. The inductive device of claim 1, wherein the first and second plurality of bond wires includes a conductive material selected from a group consisting of gold, copper, and aluminum.

10. The inductive device of claim 1, further comprises a metal shield positioned between at least a portion of the inductive device and the substrate.

11. The inductive device of claim 10, wherein the substrate is part of an integrated circuit die, and wherein the metal shield and the plurality of wire bond pads are formed from a top metal layer of the integrated circuit die.

12. The inductive device of claim 11, wherein the top metal layer is formed from at least a metal selected from a group consisting of aluminum and copper.

13. The inductive device of claim 1, wherein the inductive device is characterized as a transformer.

14. The inductive device of claim 1, wherein the inductive device is characterized as an inductor.

15. An inductive device, comprising:

a core coupled to a substrate; and

a conductive coil surrounding the core, the coil comprising segments formed from a first plurality of bond wires and a second plurality of bond wires, the first plurality of bond wires extending between the core and the substrate, each of the first plurality of bond wires coupled to two of a plurality of wire bond pads, and the second plurality of bond wires extending over the core and coupled between two of the plurality of wire bond pads, wherein the substrate is part of an integrated circuit die, the core being located over the die, and wherein the core is coupled to the substrate using epoxy, the first plurality of bond wires extending through the epoxy.

16. The inductive device of claim 15 wherein the first plurality of bond wires are insulated and the second plurality of bond wires are insulated.

17. A method for forming an inductive device, comprising:

attaching a first plurality of bond wires between first pairs of a plurality of wire bond pads;

positioning a core over the first plurality of bond wires;

attaching a second plurality of bond wires between second pairs of the plurality of wire bond pads, the second plurality of bond wires extending over the core; and

coupling the core to a substrate using epoxy, the first plurality of bond wires extending through the epoxy.

18. The method of claim 17, wherein the plurality of wire bond pads is coupled to a substrate, wherein the substrate is made of a silicon material.

19. The method of claim 17, wherein the plurality of wire bond pads is coupled to a substrate, wherein the substrate is made of a semiconductor material.

20. The method of claim 17, wherein the plurality of wire bond pads is coupled to a substrate, wherein a metal shield is positioned between the core and the substrate.

21. The method of claim 20, wherein the metal shield and the plurality of wire bond pads include aluminum.

22. The method of claim 17, wherein the core includes a magnetic material selected from a group consisting of a ferrite material and a ferromagnetic material.

23. The method of claim 17, further comprising providing a standoff for supporting the core a predetermined distance above a surface.

24. The method of claim 17, wherein the first and second plurality or bond wires includes a conductive material selected from a group consisting of gold, copper, and aluminum.

25. The method of claim 17, wherein the substrate is part of an integrated circuit die, the core being positioned over the die.

26. The method of claim 17 wherein the first plurality of bond wires are insulated and the second plurality of bond wires are insulated.