Multilayer circuit devices and manufacturing methods using electroplated sacrificial structures

• US 20050161826A1
• Filed: 03/22/2005
• Published: 07/28/2005
• Est. Priority Date: 09/27/2002
• Status: Active Grant

• Current Assignee: Medtronic Minimed Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Minimed Incorporated (Medtronic Plc)
• Inventors: Shah, Rajiv, Pendo, Shaun
• Granted Patent: US 8,003,513 B2
• Time in Patent Office: Days
• US Class Current: 257/758
• CPC Class Codes: H01L 21/4857 Multilayer substrates multilayer metallisation on monolayer substrate H01L21/4846
• CPC Class Codes: H01L 21/4867 Applying pastes or inks, e.g. screen printing H01L21/486 takes precedence
• CPC Class Codes: H01L 2224/48227 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/49171 Fan-out arrangements
• 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 2924/19105 in a side-by-side arrangement on a common die mounting substrate
• CPC Class Codes: H05K 1/162 incorporating printed capacitors
• CPC Class Codes: H05K 2201/0179 Thin film deposited insulating layer, e.g. inorganic layer for printed capacitor
• CPC Class Codes: H05K 2203/0278 Flat pressure, e.g. for connecting terminals with anisotropic conductive adhesive
• CPC Class Codes: H05K 2203/085 Using vacuum or low pressure
• CPC Class Codes: H05K 2203/1476 Same or similar kind of process performed in phases, e.g. coarse patterning followed by fine patterning
• CPC Class Codes: H05K 2203/308 Sacrificial means, e.g. for temporarily filling a space for making a via or a cavity or for making rigid-flexible PCBs
• CPC Class Codes: H05K 3/048 using a lift-off resist pattern or a release layer pattern
• CPC Class Codes: H05K 3/06 the conductive material being removed chemically or electrolytically, e.g. by photo-etch process semi-additive methods H05K3/108
• CPC Class Codes: H05K 3/4053 by thick-film techniques
• CPC Class Codes: H05K 3/4061 for via connections in inorganic insulating substrates
• CPC Class Codes: H05K 3/4664 Adding a circuit layer by thick film methods, e.g. printing techniques or by other techniques for making conductive patterns by using pastes, inks or powders H05K3/4647 takes precedence
• CPC Class Codes: H05K 3/467 Adding a circuit layer by thin film methods H05K3/4647 takes precedence

Abstract

A multilayer circuit includes a dielectric base substrate, conductors formed on the base substrate and a vacuum deposited dielectric thin film formed over the conductors and the base substrate. The vacuum deposited dielectric thin film is patterned using sacrificial structures formed by electroplating techniques. Substrates formed in this manner enable significant increases in circuit pattern miniaturization, circuit pattern reliability, interconnect density and significant reduction of over-all substrate thickness.

Claims

1. A method for forming a multilayer circuit device, comprising:

providing a base substrate;

forming at least one conductor on the base substrate;

electroplating at least one sacrificial structure on at least one of the base substrate and conductors to define areas to be protected from deposition of a dielectric layer;

depositing a thin film of a predetermined material having a predetermined electrical or structural characteristic on at least a portion of the base substrate, the at least one conductor and the at least one electroplated sacrificial structure; and

removing the sacrificial structures to leave a patterned deposited thin film of the predetermined material on the conductors and the base substrate.

2. The method claimed in claim 1, wherein depositing a thin film of a predetermined material comprises depositing a thin film of a dielectric material.

3. The method claimed in claim 1, wherein depositing a thin film of a predetermined material comprises depositing a thin film of an alumina material.

4. The method claimed in claim 1, wherein electroplating at least one sacrificial structure comprises forming a plurlality of sacrifical structures by electroplating an electroplatable material onto at least a portion of the at least one conductors and base substrate.

5. The method claimed in claim 1, wherein depositing a thin film of a predetermined material comprises vacuum depositing a thin film of the predetermined material.

6. The method claimed in claim 1, wherein depositing a thin film of a predetermined material comprises vacuum depositing a thin film of a dielectic material.

7. The method claimed in claim 1, wherein removing the sacrificial structures to leave a patterned deposited thin film of the predetermined material comprises applying an etchant to the sacrificial structures.

8. The method claimed in claim 7, wherein applying an etchant to the sacrificial structures comprises selecting and applying an etchant for a period of time, where the etchant is selected and the period of time is selected to cause removal of the sacrificial material without removing so much of the predetermined material as to eliminate its predetermined electrical or structural characteristic.

9. The method claimed in claim 1, wherein electroplating at least one sacrificial structure comprises electroplating a gold material to form at least one electroplated gold sacrificial structure.

10. The method claimed in claim 9, wherein applying an etchant to the sacrifical structures comprises applying a ferric chlorice solution to the sacrificial structures.

11. The method claimed in claim 1, wherein electroplating at least one sacrificial structure comprises electroplating at least one sacrificial structure that has a thickness that is greater than the thickness of the thin film of predetermined material.

12. The method claimed in claim 1, wherein:

depositing a thin film of a predetermined material comprises depositing a thin film of alumina;

electroplating at least one sacrificial structure comprises electroplating a gold material to form at least one electroplated gold sacrificial structure; and

applying an etchant to the sacrifical structures comprises applying a ferric chlorice solution to the alumina thin film and gold sacrificial structures.

13. The method claimed in claim 1, wherein providing a base substrate comprises providing a flexible substrate formed of a flexible material.

14. The method claimed in claim 1, wherein the base substrate comprises a hermetic via, and wherein at least one of conductor is formed in contact the hermetic via.

15. A multilayer circuit device, comprising:

a base substrate;

at least one conductor formed on the base substrate; and

a patterned thin film of a predetermined material formed on the base substrate and the conductor, the predetermined material having been patterned by a pattern of electroplated sacrifical structures that were removed to form a predefined pattern in the thin film of predetermined material.

16. The multilayer circuit device claimed in claim 15, wherein the patterned thin film of a predetermined material comprises a patterned thin film of a dielectric material.

17. The multilayer circuit device claimed in claim 15, wherein the patterned thin film of a predetermined material comprises a patterned thin film of an alumina material.

18. The multilayer circuit device claimed in claim 15, wherein the patterned thin film of a predetermined material comprises a patterned thin film of vacuum deposited material.

19. The multilayer circuit device claimed in claim 15, wherein the patterned thin film of a predetermined material comprises a patterned thin film of vacuum deposited dielectric material.

20. The multilayer circuit device claimed in claim 15, wherein the patterned thin film of a predetermined material comprises a patterned thin film of vacuum deposited alumina.

21. The multilayer circuit device claimed in claim 15, wherein the sacrificial structures comprises structures of electroplated gold material.

22. The multilayer circuit device claimed in claim 15, wherein:

the thin film of a predetermined material comprises a thin film of alumina; and

the sacrificial structures comprises structrures of electroplated gold material.

23. The multilayer circuit device claimed in claim 15, wherein the base substrate comprises a hermetic via, and wherein at least one of conductor is in contact the hermetic via.

24. The multilayer circuit device claimed in claim 15, wherein the base substrate comprises a flexible substrate formed of a flexible material.

25. A sensor device having a multilayer circuit, the sensor device comprising:

a base substrate;

at least one conductor formed on the base substrate;

a patterned thin film of a predetermined material formed on the base substrate and the conductor, the predetermined material having been patterned by a pattern of electroplated sacrifical structures that were removed to form a predefined pattern in the thin film of predetermined material;

wherein the patterned thin film material forms at least part of a sensor circuit.

26. The sensor device claimed in claim 25, wherein the patterned thin film of a predetermined material comprises a patterned thin film of a dielectric material.

27. The sensor device claimed in claim 25, wherein the patterned thin film of a predetermined material comprises a patterned thin film of an alumina material.

28. The sensor device claimed in claim 25, wherein the patterned thin film of a predetermined material comprises a patterned thin film of vacuum deposited material.

29. The sensor device claimed in claim 25, wherein the sacrificial structures comprises structures of electroplated gold material.

30. The sensor device claimed in claim 25, wherein:

the thin film of a predetermined material comprises a thin film of alumina; and

the sacrificial structures comprises structrures of electroplated gold material.

31. The sensor device claimed in claim 25, wherein the base substrate comprises a flexible substrate formed of a flexible material.