High Q factor inductor structure

• US 9,196,406 B2
• Filed: 12/06/2013
• Issued: 11/24/2015
• Est. Priority Date: 03/15/2013
• Status: Active Grant

• Current Assignee: Qorvo US, Inc. (Qorvo, Inc.)
• Original Assignee: RF Micro Devices Incorporated (Qorvo, Inc.)
• Inventors: Leipold, Dirk Robert Walter, Chang, Danny W., Maxim, George, Bauder, Ruediger
• Primary Examiner(s): Lian, Mangtin
• Application Number:
  US14/099,007
• Publication Number:
  US 20140266544A1
• Time in Patent Office: 718 Days
• Field of Search: 336/220, 336/223, 336/192, 336/186, 257/531, 257/48, 257/421, 257/427, 257/621
• US Class Current: 1/1
• CPC Class Codes: H01F 17/0013 with stacked layers
• CPC Class Codes: H01F 2017/002 Details of via holes for interconnecting the layers
• CPC Class Codes: H01F 2017/0073 with a special conductive pattern, e.g. flat spiral
• CPC Class Codes: H01F 5/003 Printed circuit coils

Abstract

The present disclosure provides a vertical inductor structure in which the magnetic field is closed such that the magnetic field of the vertical inductor structure is cancelled in the design direction outside the vertical inductor structure, yielding a small, or substantially zero, coupling factor of the vertical inductor structure. In one embodiment, several vertical inductor structures of the present disclosure can be placed in close proximity to create small resonant circuits and filter chains.

Claims

1. An inductor structure in a substrate comprising:

a first connector plate;

a second connector plate;

a third connector plate;

a first terminal plate;

a second terminal plate;

a first elongated via column that is elongated along a first plane, wherein the first elongated via column connects the first terminal plate to the first connector plate;

a second elongated via column that is elongated along a second plane, wherein the second elongated via column connects the second terminal plate to the second connector plate and wherein the first elongated via column and the second elongated via column are positioned such that the first plane is substantially perpendicular to the second plane;

a third elongated via column that is elongated along a third plane, wherein the third elongated via column connects the first connector plate to the third connector plate and wherein the third elongated via column is positioned such that the third plane is substantially perpendicular to the first plane and is substantially parallel to the second plane;

a fourth elongated via column that is elongated along a fourth plane, wherein the fourth elongated via column connects the second connector plate to the third connector plate and wherein the fourth elongated via column is positioned such that the fourth plane is substantially perpendicular to the both the second plane and the third plane and is substantially parallel to the first plane; and

wherein the third connector plate is connected from the third elongated via column to the fourth elongated via column such that the third connector plate is substantially perpendicular to the first connector plate and the second connector plate and such that current propagates in opposite directions through the first connector plate and the second connector plate.

2. The inductor structure of claim 1, wherein least two terminal plates the first terminal plate and the second terminal plate enable an active device on the substrate to be connected to the inductor structure in the substrate.

3. The inductor structure of claim 1, wherein the first terminal plate, the second terminal plate the first connector plate, the second connector plate, and the third connector plate are created with conductive layers of the substrate.

4. The inductor structure of claim 1, wherein the first elongated via column, the second elongated via column, the third elongated via column, and the fourth elongated via column are created in non-conductive layers of the substrate.

5. The inductor structure of claim 4, wherein:

the first elongated via column is formed from a first stack of solid via bars;

the second elongated via column is formed from a second stack of solid via bars;

the third elongated via column is formed from a third stack of solid via bars;

the fourth elongated via column is formed from a fourth stack of solid via bars; and

a height of the solid via bars in the first stack, the second stack, the third stack, and the fourth stack each corresponds to a depth of a non-conductive layer of the substrate.

6. The inductor structure of claim 5, wherein a height of the first solid via column, the second elongated via column, the third elongated via column, and the fourth elongated via column each corresponds to the height of the at least one solid via bar.

7. The inductor structure of claim 6, wherein the first solid via column, the second elongated via column, the third elongated via column, and the fourth elongated via column are each stacked vertically in the substrate.

8. The inductor structure of claim 1, wherein the inductor structure has a high quality (Q) factor.

9. The inductor structure of claim 8, wherein a value of the high Q factor is greater or equal to 100.

10. The inductor structure of claim 8, wherein the value of the high Q factor is increased by increasing a width of each of the first solid via column, the second elongated via column, the third elongated via column, and the fourth elongated via column.

11. The inductor structure of claim 1, wherein the inductor structure is configured to generate a magnetic field such that the magnetic field is closed to an interior of the inductor structure.

12. The inductor structure of claim 11, wherein each of the first solid via column, the second elongated via column, the third elongated via column, and the fourth elongated via column has a column width so that the column width of each of the first solid via column, the second elongated via column, the third elongated via column, and the fourth elongated via column are equal.

13. The inductor structure of claim 12, wherein the inductor structure is configured to provide a small coupling factor.

14. The inductor structure of claim 13, wherein the small coupling factor is substantially zero.

15. The vertical inductor structure of claim 1, wherein the vertical inductor structure is configured to generate a magnetic field, where the magnetic field is not closed to an interior of the vertical inductor structure.

16. The vertical inductor structure of claim 15, wherein the magnetic field is not closed to the interior of the vertical inductor structure when a width of each of the at least four solid via columns are not equal.

17. The vertical inductor structure of claim 16, wherein the vertical inductor structure further comprises a non-zero coupling factor.

18. The vertical inductor structure of claim 1, wherein the vertical inductor is spherical.

19. The inductor structure of claim 1, wherein the inductor structure is configured to generate a magnetic field, and wherein the first solid via column, the second elongated via column, the third elongated via column, the fourth elongated via column, the first terminal plate, the second terminal plate, the first connector plate, the second connector plate, and the third connector plate are arranged such that the magnetic field is substantially confined to an interior of the inductor structure.

20. The inductor structure of claim 1, wherein the first elongated via column and the second elongated via column are each configured to have a first width and the third elongated via column and the fourth elongated via column are each configured to have a second width, the first width being greater than the second width.

21. The inductor structure of claim 1, wherein the third elongated via column and the fourth elongated via column are each configured to have a first width and the first elongated via column and the second elongated via column are each configured to have a second width, the first width being greater than the second width.

22. The inductor structure of claim 1, wherein the first solid via column, the second elongated via column, the third elongated via column, the fourth elongated via column, the first connector plate, the second connector plate, and the third connector plate are coupled such that the inductor structure has a square footprint in a first direction and has a square footprint along a second direction.

23. The inductor structure of claim 1, wherein the first solid via column, the second elongated via column, the third elongated via column, the fourth elongated via column, the first connector plate, the second connector plate, and the third connector plate are coupled such that an interior of the inductor structure encloses a cube.

24. An inductor in a substrate, comprising:

a first connector plate;

a second connector plate;

a third connector plate;

a first terminal plate;

a second terminal plate;

a first elongated via column that is elongated along a first plane, wherein the first elongated via column connects the first terminal plate to the first connector plate;

a second elongated via column that is elongated along a second plane, wherein the second elongated via column connects the second terminal plate to the second connector plate and wherein the first elongated via column and the second elongated via column are positioned such that the first plane is substantially perpendicular to the second plane;

a third elongated via column that is elongated along a third plane, wherein the third elongated via column connects the first connector plate to the third connector plate and wherein the third elongated via column is positioned such that the third plane is substantially perpendicular to the first plane and is substantially parallel to the second plane;

a fourth elongated via column that is elongated along a fourth plane, wherein the fourth elongated via column connects the second connector plate to the third connector plate and wherein the fourth elongated via column is positioned such that the fourth plane is substantially perpendicular to the both the second plane and the third plane and is substantially parallel to the first plane; and

wherein the third connector plate is connected from the third elongated via column to the fourth elongated via column such that the third connector plate is substantially perpendicular to the first connector plate and the second connector plate and such that current propagates in opposite directions through the first connector plate and the second connector plate.

25. The inductor of claim 24, wherein the first terminal plate and the second terminal plate enable an active device on the substrate to be connected to the vertical inductor in the substrate.

26. The inductor of claim 25, wherein the inductor structure has a high quality (Q) factor.

27. The inductor of claim 26, wherein a value of the high Q factor has is greater or equal to 100.

28. The inductor of claim 26, wherein the high Q factor is increased by increasing a width of each of the first solid via column, the second elongated via column, the third elongated via column, and the fourth elongated via column.

29. The inductor of claim 24, wherein the inductor is configured to generate a magnetic field such that the magnetic field is running parallel to a design plane of the substrate.

30. The vertical inductor of claim 24, wherein the vertical inductor is spherical.

31. The inductor of claim 24, wherein the inductor is configured to generate a magnetic field, and wherein the first solid via column, the second elongated via column, the third elongated via column, the fourth elongated via column, the first terminal plate, the second terminal plate, the first connector plate, the second connector plate, and the third connector plate are arranged such that the magnetic field is substantially confined to an interior of the inductor.