Surface inductor

• US 7,310,039 B1
• Filed: 11/30/2001
• Issued: 12/18/2007
• Est. Priority Date: 11/30/2001
• Status: Active Grant

• Current Assignee: Silicon Laboratories Incorporated
• Original Assignee: Silicon Laboratories Incorporated
• Inventors: Zhang, Ligang
• Primary Examiner(s): Nguyen; Tuyen T.
• Application Number:
  US09/997,378
• Time in Patent Office: 2,209 Days
• Field of Search: 336/65, 336/83, 336/192, 336/200, 336/232, 257/531
• 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 2017/0073 with a special conductive pattern, e.g. flat spiral
• CPC Class Codes: H01L 23/645 Inductive arrangements H01L23/647, H01L23/66 take precedence
• 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

Abstract

It has been discovered that an inductor may be made to include a surface rotational portion instead of a coil to provide a low inductance inductor with sufficient quality factor. The surface rotational portion is a conducting structure which is substantially enclosed along the length of the structure and which has openings at each end of the structure and an opening along the length of the structure between the end openings. One example of such a structure is a cylinder having a lateral opening and openings at its ends or bases. Another example of such a structure is a duct-shape or rectangular structure. Any appropriately shaped surface may be used to rotate current, and varying thicknesses and lengths may be used as appropriate.

Claims

1. An inductor comprising a surface rotational portion, the surface rotational portion including first and second base edges,

wherein the surface rotational portion has a length measured from the first base edge to the second base edge, the length being substantially larger than a thickness of the surface rotational portion, and

wherein the surface rotational portion comprises a plurality of substantially flat sides.

2. The inductor of claim 1 wherein the length of surface rotational portion is of substantially the same order of magnitude as each of the height and width of the surface rotational portion.

3. The inductor of claim 1 wherein the length of surface rotational portion is substantially larger than each of the height and width of the surface rotational portion.

4. The inductor of claim 1, further comprising:

an input node coupled to a first side edge of the surface rotational portion, the first side edge extending along the length of the inductor from a first base end of the inductor to a second base end of the inductor;

an output node coupled to a second side edge of the surface rotational portion, the second side edge extending along the length of the inductor from a first base end of the inductor to a second base end of the inductor, the first and second side edges being at opposite ends of the surface rotational portion.

5. The inductor of claim 4 wherein the input and output nodes are surface nodes.

6. The inductor of claim 1, wherein the surface rotational portion is substantially electrically symmetrical with respect to current.

7. The inductor of claim 1, wherein the surface rotational portion is formed to guide current flow in one loop.

8. The inductor of claim 1, wherein the surface rotational portion is formed such that the surface rotational portion has a face which may be generated by a family of all lines parallel to a given generatrix line and passing through a directrix curve in a plane.

9. The inductor of claim 8, wherein the directrix curve is rectangular.

10. The inductor of claim 1, wherein the surface rotational portion is duct shaped.

11. The inductor of claim 1, wherein the plurality of substantially flat sides comprise:

a first substantially flat side coupled to receive a current from an input node;

a second substantially flat side coupled to receive the current from the first substantially flat side;

a third substantially flat side coupled to receive the current from the second substantially flat side; and

a fourth substantially flat side coupled to receive the current from the third substantially flat side and to provide the current to an output node.

12. The inductor of claim 11, wherein

the first and third sides are substantially parallel;

and

the second and fourth sides are substantially parallel.

13. The inductor of claim 12, wherein the first side is substantially perpendicular to the second side.

14. The inductor of claim 1, wherein the plurality of substantially flat sides comprise:

a first substantially flat side coupled to receive a current from an input node;

a second substantially flat side coupled to receive the current from the first substantially flat side;

a third substantially flat side coupled to receive the current from the second substantially flat side;

a fourth substantially flat side coupled to receive the current from the third substantially flat side; and

a fifth substantially flat side coupled to receive the current from the fourth substantially flat side and to provide the current to an output node.

15. The inductor of claim 14, wherein

the first and third sides are substantially parallel;

the second and fourth sides are substantially parallel; and

the first side is substantially perpendicular to the second side.

16. The inductor of claim 15, wherein the first and fifth sides are in substantially the same plane.

17. The inductor of claim 15, wherein each of the second and fourth sides are vertical in an integrated circuit, and comprise a plurality of spaced, parallel, vertical cylinders.

18. The inductor of claim 1,

wherein a first one of the plurality of substantially flat sides is coupled to receive a current from an input node, a second one of the plurality of substantially flat sides is coupled to provide a current to an output node, and the other ones of the plurality of substantially flat sides are coupled in series between the first and second ones of the plurality of substantially flat sides.

19. The inductor of claim 1, wherein the surface rotational portion has a face which may be generated by moving a curve around a central axis line at a distance from the central axis line.

20. The inductor of claim 19, wherein the distance has different values at different angular locations around the central axis line.

21. The inductor of claim 1 wherein a ratio of the length of the surface rotational portion to the thickness of the surface rotational portion is greater than 5:

1.

22. The inductor of claim 21 wherein a ratio of the length of the surface rotational portion to the thickness of the surface rotational portion is in a range from 50:

1 to 1000;

1.

23. An integrated circuit comprising at least one inductor of claim 1.

24. An information processing system including an integrated circuit comprising at least one inductor of claim 1.

25. The inductor of claim 1 wherein the surface rotational portion is an electrical conductor.