Multilayer composite and a method of making such

• US 20070116858A1
• Filed: 11/03/2006
• Published: 05/24/2007
• Est. Priority Date: 11/02/2000
• Status: Active Grant

• Current Assignee: Danfoss A/S
• Original Assignee: Danfoss A/S
• Inventors: Gravesen, Peter, Benslimane, Mohamed
• Granted Patent: US 8,181,338 B2
• Time in Patent Office: Days
• US Class Current: 427/58
• CPC Class Codes: B81B 3/0021 Transducers for transforming electrical into mechanical energy or vice versa dynamo-electric machines H02K99/00; electrostatic machines H02N1/00; piezoelectric devices H10N30/00
• CPC Class Codes: H02N 1/006 of the gap-closing type H02N1/004 takes precedence
• CPC Class Codes: H10N 30/05 Manufacture of multilayered piezoelectric or electrostrictive devices, or parts thereof, e.g. by stacking piezoelectric bodies and electrodes
• CPC Class Codes: H10N 30/084 by moulding or extrusion
• CPC Class Codes: H10N 30/098 Forming organic materials
• CPC Class Codes: Y10T 29/49117 Conductor or circuit manufacturing
• CPC Class Codes: Y10T 29/49124 On flat or curved insulated base, e.g., printed circuit, etc.
• CPC Class Codes: Y10T 29/49155 Manufacturing circuit on or in base

Abstract

A method for providing a multilayer composite includes the steps of providing a first composite comprising a film of a dielectric material with a front surface and an opposite rear surface, the front surface comprising a surface pattern; depositing an electrically conductive layer onto the surface pattern; providing a second composite comprising a film with a front surface and an opposite rear surface, the front surface comprising a surface pattern; depositing an electrically conductive layer covering at least a portion of the surface pattern; arranging the first composite on the second composite; and fixating the position of the first composite relative to the second composite.

Claims

1. A method of providing a multilayer composite of layers of a dielectric film and an electrically conductive layer, the method comprising:

providing a first composite comprising a film of a dielectric material with a front surface and an opposite rear surface, the front surface comprising a surface pattern of raised and depressed surface portions,

depositing an electrically conductive layer onto the surface pattern,

providing a second composite comprising a film with a front surface and an opposite rear surface, the front surface comprising a surface pattern of raised and depressed surface portions,

depositing an electrically conductive layer covering at least a portion of the surface pattern,

arranging the first composite on the second composite, and

fixating the position of the first composite relative to the second composite.

2. The method according to claim 1, wherein the position is fixed by use of an adhesive provided between the composites.

3. The method according to claim 2, wherein the position is fixed by use of fixation means located at a rim portion of the composites.

4. The method according to claim 1, wherein the composites are arranged on each other in a process in which the composites are moved forward in a process direction while being biased towards each other.

5. The method according to claim 1, wherein the film of each composite is provided by providing a shape defining element having a surface pattern of raised and depressed surface portions and by providing a liquid polymer composition onto the surface pattern to form a first film having a surface with a replicated pattern of raised and depressed surface portions.

6. The method according to claim 5, wherein the film of each composite is provided by use of identical shape defining elements, or by use of the same shape defining element, and wherein the composites are displaced relative to each other to displace film errors which are caused by the shape defining element relative to each other.

7. A method according to claim 5, further comprising the step of

depositing a first electrically conductive layer onto the replicated surface pattern.

11. The method according to claim 1, wherein the step of coating the film with a first electrically conductive layer comprises the step of using a shape of the film to shape the electrically conductive layer.

12. The method according to claim 1, wherein the electrically conductive layer is deposited on the film in a physical vapour deposition process.

13. The method according to claim 1, wherein the electrically conductive layer is deposited onto the film in a thickness of 0.01-0.1 μ

m.

14. The method according to claim 13, wherein the thickness is controlled by quartz crystal micro balance.

15. A method according to claim 13, wherein the electrically conductive layer is made in a sputtering process.

16. The method according to claim 13, wherein the electrically conductive layer is made in an electron beam process.

17. The method according to claim 1, wherein the film is treated with a plasma to improve adhesion of the electrically conductive layer.

18. The method according to claim 17, wherein the treatment is conducted with a glow discharge which is known to generate mild plasma.

19. The method according to claim 17, wherein an adhesion promoter is applied to at least said portion of the film after the step of plasma treating and before the step of depositing the electrically conductive layer thereon.

20. The method according to claim 19, wherein the adhesion promoter is provided by applying a layer of chromium or titanium between the film and the electrically conductive layer.

21. The method according to claim 19, wherein the adhesion promoter is applied to the film of the dielectric material in a physical vapour deposition process.

8. A method of making a multilayer composite, the method comprising:

providing a shape defining element having a surface pattern of raised and depressed surface portions,

providing a liquid polymer composition onto the surface pattern,

curing the liquid polymer composition to form a first film having a surface with a replicated pattern of raised and depressed surface portions,

coating at least a portion of the replicated pattern with a first electrically conductive layer,

providing a liquid polymer composition directly onto the first film or onto the electrically conductive layer to provide a second film,

pre-curing the liquid polymer composition,

embossing a shape defining element into the second film to provide a second replicated pattern,

curing the polymer composition of the second film, and

coating at least a portion of the second replicated pattern with a second electrically conductive layer.

9. The method according to claim 8, wherein at least the steps of

providing a liquid polymer composition directly onto a film or onto an electrically conductive layer of the multilayer composite to provide another film,

pre-curing the liquid polymer composition,

embossing a shape defining element into the second film to provide another replicated pattern,

curing the polymer composition of the second film, and

coating at least a portion of the replicated pattern with an electrically conductive layer,

is repeated to provide a plurality of layers in the multilayer composite.

10. The method according to claim 8, wherein the step of providing a shape defining element is repeated with elements having different surface patterns.