Integrated inductive components and method of fabricating such components

• US 6,249,039 B1
• Filed: 09/10/1998
• Issued: 06/19/2001
• Est. Priority Date: 09/10/1998
• Status: Expired due to Fees

• Current Assignee: Bourns Incorporated
• Original Assignee: Bourns Incorporated
• Inventors: Stephenson, James Craig, Ehman, Michael Frederick, Harvey, Malcolm Randall, Harvey, Ian Robert
• Primary Examiner(s): Picardat, Kevin M.
• Assistant Examiner(s): COLLINS, DEVEN M
• Application Number:
  US09/151,410
• Time in Patent Office: 1,013 Days
• Field of Search: 257/531, 257/528, 257/549, 257/550, 438/381, 438/406, 438/421, 438/238, 438/171, 438/329
• US Class Current: 257/531
• CPC Class Codes: H01F 17/0006 Printed inductances printed coils for dynamo-electric machines H02K3/26; printed circuits H05K
• CPC Class Codes: H01F 17/0033 with the coil helically wound around a magnetic core
• CPC Class Codes: H01F 41/042 by thin film techniques
• 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 inductive component includes a substrate on the surface of which is a lower insulation layer having a shallow concavity or trench, a first plurality of conductive elements formed in the trench, a magnetic core formed over the first plurality of conductive elements, and a second plurality of conductive elements formed over the core. The first and second pluralities of conductive elements are connected to each other so as to form an inductive coil around the core. First and second core insulation layers are disposed between the core and the first and second pluralities of conductive elements, respectively. The component is fabricated by a method in which it is built up in the trench using thin film techniques. A first array of conductors is patterned over the lower insulation layer, and a first core insulation layer is applied over the first conductor array. A magnetic core is formed on top of the first core insulation layer, and a second core insulation layer is applied over the core. A second array of conductors is patterned on top of the second core insulation layer so that the ends of the conductors in the first and second arrays contact each other to form an inductive coil around the core. The formation of either the first or second plurality of conductors may coincide with the formation of the metal conductor layer in the manufacture of a semiconductor integrated circuit, whereby the inductive component can be manufactured as part of the integrated circuit.

Claims

1. An inductive component formed on a substrate, comprising:

a lower insulation layer formed on a surface of the substrate, the lower insulation layer having a concave depression and formed of a material consisting essentially of benzocyclobutene;

a first array of conductive elements formed in the depression, each of the first array of conductive elements having first and second ends;

a core insulation layer formed over the first array of conductive elements so as to leave the first and second ends thereof exposed and formed of a material consisting essentially of benzocyclobutene; and

a second array of conductive elements formed over the core insulation layer, each of the second array of conductive elements having first and second ends, wherein the second array of conductive elements is formed so that the first and second ends of the conductive elements in the second array are respectively connected to the first and second ends of the conductive elements in the first array so as to form an inductive coil.

2. The inductive component of claim 1, wherein the core insulation layer is a first core insulation layer, the component further comprising:

a ferromagnetic core formed on the first core insulation layer; and

a second core insulation layer formed over the ferromagnetic core;

wherein the second array of conductive elements is formed over the second core insulation layer.

3. The inductive component of claim 2, further comprising:

a ferromagnetic shield layer disposed with respect to at least one of the arrays of conductive elements so as to contain the magnetic field generated by the inductive component.

4. The inductive component of claim 3, wherein the ferromagnetic shield layer comprises:

a lower ferromagnetic shield layer disposed between the lower insulation layer and the first array of conductive elements.

5. The inductive component of claim 4, further comprising:

a lower shield insulation layer disposed between the lower ferromagnetic shield layer and the first array of conductive elements.

6. The inductive component of claim 3, wherein the ferromagnetic shield layer comprises:

an upper ferromagnetic shield layer formed over the second array of conductive elements.

7. The inductive component of claim 6, further comprising:

a lower shield insulation layer disposed between the upper ferromagnetic shield layer and the second array of conductive elements.

8. The inductive component of any of claims 2, 3, 4, 5, 6, or 7, wherein the lower insulation layer, the first core insulation layer, and the second core insulation layer are formed from a material consisting essentially of benzocyclobutene.

9. The inductive component of claim 5, wherein the lower shield insulation layer is formed from a material consisting essentially of benzocyclobutene.

10. The inductive component of claim 7, wherein the upper shield insulation layer is formed from a material consisting essentially of benzocyclobutene.

11. An inductive component formed on a substrate, comprising:

a lower insulation layer formed on a surface of the substrate, the lower insulation layer having a concave depression;

a first array of conductive elements formed in the depression, each of the first array of conductive elements having first and second ends;

a first core insulation layer formed over the first array of conductive elements so as to leave the first and second ends thereof exposed;

a magnetic core formed on the first core insulation layer;

a second core insulation layer formed over the magnetic core; and

a second array of conductive elements formed over the second core insulation layer, each of the second array of conductive elements having first and second ends, wherein the second array of conductive elements is formed so that the first and second ends of the conductive elements in the second array are respectively connected to the first and second ends of the conductive elements in the first array so as to form an inductive coil.

12. The inductive component of claim 11, further comprising:

a magnetic shield layer disposed with respect to at least one of the arrays of conductive elements so as to contain the magnetic field generated by the inductive component.

13. The inductive component of claim 12, wherein the magnetic shield layer comprises:

a lower magnetic shield layer disposed between the lower insulation layer and the first array of conductive elements.

14. The inductive component of claim 13, further comprising:

a lower shield insulation layer disposed between the lower magnetic shield layer and the first array of conductive elements.

15. The inductive component of claim 12, wherein the magnetic shield layer comprises:

an upper magnetic shield layer formed over the second array of conductive elements.

16. The inductive component of claim 15, further comprising:

a lower shield insulation layer disposed between the upper magnetic shield layer and the second array of conductive elements.

17. The inductive component of any of claims 11, 12, 13, 14, 15, or 16, wherein the lower insulation layer, the first core insulation layer, and the second core insulation layer are formed from a material consisting essentially of benzocyclobutene.

18. The inductive component of claim 14, wherein the lower shield insulation layer is formed from a material consisting essentially of benzocyclobutene .

19. The inductive component of claim 16, wherein the upper shield insulation layer is formed from a material consisting essentially of benzocyclobutene.