Three-dimensional coil inductor

• US 6,417,754 B1
• Filed: 12/07/1998
• Issued: 07/09/2002
• Est. Priority Date: 12/08/1997
• Status: Expired due to Fees

• Current Assignee: Lawrence Livermore National Security LLC (Government of the United States of America)
• Original Assignee: Regents of the University of California (University of California)
• Inventors: Malba, Vincent, Bernhardt, Anthony F.
• Primary Examiner(s): MAI, ANH T
• Application Number:
  US09/206,498
• Time in Patent Office: 1,310 Days
• Field of Search: 336/200, 336/232, 336/223, 296/021, 296/05
• 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: H01F 5/003 Printed circuit coils
• 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 27/08 including only semiconductor components of a single kind
• CPC Class Codes: H01L 28/10 Inductors
• 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 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: Y10T 29/4902 Electromagnet, transformer or inductor

Abstract

A three-dimensional coil inductor is disclosed. The inductor includes a substrate; a set of lower electrically conductive traces positioned on the substrate; a core placed over the lower traces; a set of side electrically conductive traces laid on the core and the lower traces; and a set of upper electrically conductive traces attached to the side traces so as to form the inductor. Fabrication of the inductor includes the steps of forming a set of lower traces on a substrate; positioning a core over the lower traces; forming a set of side traces on the core; connecting the side traces to the lower traces; forming a set of upper traces on the core; and connecting the upper traces to the side traces so as to form a coil structure.

Claims

1. A method for fabricating a three-dimensional coil, comprising the steps of:

forming a set of lower traces on a substrate;

locating a core having dimensions significantly larger than the thickness of the lower traces over the lower traces;

forming a set of side traces on the core using a three dimensional lithography technique;

coupling the side traces to the lower traces;

forming a set of upper traces on the core; and

coupling the upper traces to the side traces so as to form a coil structure.

2. The method of claim 1, further comprising the step of:

dissolving the core.

3. The method of claim 1, wherein the forming steps comprise the step of:

forming electrically conductive traces.

4. The method of claim 3, wherein the forming steps further comprise the step of:

forming copper traces.

5. The method of claim 1, wherein the forming a set of lower traces step comprises the step of:

forming a set of lower traces on a silicon substrate.

6. The method of claim 1, wherein the forming a set of lower traces step comprises the step of:

forming a set of lower traces on a ceramic substrate.

7. The method of claim 1, wherein the step of locating a core comprises the steps of:

placing a mold over the lower traces; and

distributing a core material into the mold.

8. The method of claim 1, wherein the step of locating a core comprises the step of:

locating an insulating core over the lower traces.

9. The method of claim 1, wherein the step of locating a core comprises the step of:

locating a ferro-magnetic core over the lower traces.

10. The method of claim 1, further comprising the step of:

inserting an insulator over the lower traces before locating a core over the lower traces.

11. The method of claim 1, wherein the step of locating a core comprises the step of:

locating a ferromagnetic core with an outer insulating layer.

12. A system for fabricating a three-dimensional coil, comprising:

means for forming a set of lower traces on a substrate;

means for locating a core having dimensions significantly larger than the thickness of the lower traces over the lower traces;

means for forming a set of side traces on the core using a three dimensional lithography technique;

means for coupling the side traces to the lower traces;

means for forming a set of upper traces on the core; and

means for coupling the upper traces to the side traces so as to form a coil structure.

13. The system of claim 12, further comprising:

means for dissolving the core.

14. The system of claim 12, wherein the means for forming comprise:

means for forming electrically conductive traces.

15. The system of claim 12, further comprising:

means for inserting an insulator over the lower traces before the means for locating a core over the lower traces.

16. The system of claim 12, wherein the means for locating a core comprises:

means for placing a mold over the lower traces; and

means for distributing a core material into the mold.

17. A computer-usable medium embodying computer program code for causing a computer to fabricate a three-dimensional coil, by performing the steps of:

forming a set of lower traces on a substrate;

locating a core having dimensions significantly larger than the thickness of the lower traces over the lower traces;

forming a set of side traces on the core using a three-dimensional lithography technique;

coupling the side traces to the lower traces;

forming a set of upper traces on the core; and

coupling the upper traces to the side traces so as to form a coil structure.

18. The computer-usable medium of claim 17, further performing the step of:

dissolving the core.

19. The computer-usable medium of claim 17, wherein the forming steps performs the step of:

forming electrically conductive traces.

20. The computer-usable medium of claim 17, further performing the step of:

inserting an insulator over the lower traces before locating a core over the lower traces.

21. The computer-usable medium of claim 17, wherein the step of locating a core performs the steps of:

placing a mold over the lower traces; and

distributing a core material into the mold.

22. A method for fabricating a three-dimensional coil, comprising the steps of:

forming a set of lower traces on a substrate;

locating a core having sides substantially orthogonal to the lower traces over the lower traces;

forming a set of side traces on the core by creating a pattern on the substantially orthogonal surfaces;

coupling the side traces to the lower traces;

forming a set of upper traces on the core; and

coupling the upper traces to the side traces so as to form a coil structure.