Inductor for integrated circuit

• US 6,838,970 B2
• Filed: 07/26/2002
• Issued: 01/04/2005
• Est. Priority Date: 02/26/1999
• Status: Expired due to Term

• Current Assignee: M-Red Inc. (Quest Patent Research Corporation)
• Original Assignee: Memscap Incorporated, Planhead-Silmag Phs
• Inventors: Karam, Jean-Michel, Valentin, François, Basteres, Laurent, Mhani, Ahmed
• Primary Examiner(s): MAI, ANH T
• Application Number:
  US10/206,284
• Publication Number:
  US 20020186114A1
• Time in Patent Office: 893 Days
• Field of Search: 336/200, 336/223, 336/232, 336/192, 296/06, 296/021
• 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 2017/0046 with a conductive path having a bridge
• 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

An inductor assembly for use in RF and microwave circuits wherein the inductor is formed of a first spiral wound metal strip that is mounted on a flat surface of a quartz substrate. A metal strip is formed of copper and has a height above the flat surface that is about 30 microns.

Claims

1. An inductor assembly suitable for use in radiofrequency and microwave circuits that includes:

a substrate;

an inductor formed of a first metal strip that is wound in a spiral and being mounted upon a flat surface of said substrate,

said substrate being formed of quartz,

said spiral wound metal inductor being formed of copper;

said first metal strip having a height equal to or greater than 10 microns and

a polyimide layer mounted upon the flat surface of said substrate between said substrate and said first metal strip,

wherein said inductor contains a second spiral metal strip that is contained within said polyimide layer and which is connected in series with said first metal strip, said first and second metal strips each having a rectangular cross section and lying within parallel planes one above the other.

2. The assembly of claim 1 that further includes a barrier layer of silica positioned between said first metal strip and said polyimide layer.

3. The assembly of claim 1 wherein said inductor includes end terminals and including raised spacer elements for mounting said end terminals upon an integrated circuit.

4. An inductor assembly suitable for use in an integrated transformer that includes

an inductor formed of two copper spiral wound metal strips, a first strip being would inside a second strip so that the turns of one strip are positioned between the turns of the other strip,

said strips being mounted upon the flat surface of said substrate and each strip having a height above said flat surface greater than 10 microns,

wherein said inductor includes end terminals and including raised spacer elements for mounting said end terminals upon an integrated circuit.

5. The assembly of claim 4 wherein the height of said strips is about 30 microns.

6. The assembly of claim 4 that further includes a polyimide layer that is located between the inductor and the flat surface of said substrate said spiral metal strips being mounted upon said polyimide layer and connector segments mounted within said polyimide layer for connecting the inner ends of the metal strips to end terminals.

7. The assembly of claim 4 wherein surfaces of said metal strips exposed to atmosphere are coated with a layer of gold.

8. The assembly of claim 4 wherein each metal strip is in the form of a circular spiral.

9. The assembly of claim 4 wherein a space is provided between adjacent turns of the first and second metal strips.

10. The assembly of claim 4 wherein each spiral metal strip includes end terminals that are mounted upon spacer elements, said spacer elements in turn being mounted upon an integrated circuit board, the height of each spacer element being about equal to the height of the metal strips.

11. The assembly of claim 10 wherein said integrated circuit board further includes mounting pads upon which the spacer elements are seated to provide an electrical connection between the integrated circuit board and the inductor.

12. The assembly of claim 11 wherein said spacer elements are cylindrical in form and the outer diameter of each spacer is about three times the height of said spacer elements.