Multilayer conductive elements

• US 7,777,397 B2
• Filed: 03/12/2007
• Issued: 08/17/2010
• Est. Priority Date: 03/12/2007
• Status: Expired due to Fees

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Michel, Matthew J., Bharti, Vivek
• Primary Examiner(s): Benson; Walter
• Assistant Examiner(s): ROSENAU, DEREK JOHN
• Application Number:
  US11/684,700
• Publication Number:
  US 20080224566A1
• Time in Patent Office: 1,254 Days
• Field of Search: 310/311, 310/365, 310/366, 29/253.5
• US Class Current: 310/365
• CPC Class Codes: B29C 48/08 flexible, e.g. films
• CPC Class Codes: B29C 48/19 the layers being joined at their edges
• CPC Class Codes: B29C 48/21 the layers being joined at their surfaces
• CPC Class Codes: B29C 48/307 specially adapted for bringing together components, e.g. melts within the die
• CPC Class Codes: H01L 21/32056 Deposition of conductive or semi-conductive organic layers H01L21/32058 takes precedence
• CPC Class Codes: H05K 2201/09881 Coating only between conductors, i.e. flush with the conductors
• CPC Class Codes: H05K 3/101 by casting or moulding of conductive material
• 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: H10N 30/067 Forming single-layered electrodes of multilayered piezoelectric or electrostrictive parts
• CPC Class Codes: H10N 30/084 by moulding or extrusion
• CPC Class Codes: H10N 30/098 Forming organic materials
• CPC Class Codes: H10N 30/50 having a stacked or multilayer structure
• CPC Class Codes: H10N 30/871 Single-layered electrodes of multilayer piezoelectric or electrostrictive devices, e.g. internal electrodes
• CPC Class Codes: Y10T 29/42 Piezoelectric device making

Abstract

An article comprises first and second electrically responsive elements having a cutting plane which is perpendicular to an x-dimension for separating the elements. The conductive elements of the conductive layers are alternatingly exposed to one of the two opposing faces of the conductive element.

Claims

1. An article having an x-dimension, a y-dimension and a z-dimension, the three dimensions being mutually orthogonal, the article comprising:

a. at least two conductive layers extending in the x-dimension, each conductive layer comprising alternating conductive regions and nonconductive regions;

b. at least one nonconductive layer; and

wherein the at least two conductive layers and the at least one nonconductive layer alternate in the z-dimension

wherein the at least two conductive layers and the at least one nonconductive layer form at least a first and a second electrically responsive element, wherein the at least one nonconductive layer of the first electrically responsive element and the at least one nonconductive layer of the second electrically responsive element form a substantially continuous nonconductive layer in the x-dimension;

wherein the at least first and second electrically responsive elements each have two opposing faces coincident with the y-z plane,

wherein the first electrically responsive element comprises a first conductive region; and

a third conductive region,

wherein the first conductive region has a first surface and the third conductive region has a second surface,

wherein the first surface of the first conductive region is exposed to a first opposing face of the first element and the second surface of the third conductive region is exposed to a second opposing face of the first element

wherein the second electrically responsive element comprises a second conductive region; and

a fourth conductive region,

wherein the second conductive region has a first surface and the fourth conductive region has a second surface,

wherein the first surface of the second conductive region is exposed to a first opposing face of the second element and the second surface of the fourth conductive region is exposed to a second opposing face of the second element

wherein the first conductive layer comprises the first and second conductive regions and the second conductive layer comprises the third and fourth conductive regions.

2. The article of claim 1, wherein the first and second electrically responsive elements are each made from a unit cell, each unit cell independently comprising:

at least a portion of the at least one nonconductive layer, and

at least a portion of each of the at least two conductive layers.

3. The article according to claim 2, wherein

the nonconductive layer comprises a polymeric nonconductive material having third and fourth surfaces that are continuous along the x-dimension and the y-dimension;

the at least two conductive layers each comprise polymeric conductive material,

wherein the first surface of the first conductive region of the first conductive layer is coincident with a reference plane, and the second surface of the first conductive region of the first conductive layer not extending to a cutting plane;

the second surface of the third conductive region of the second conductive layer coincident with the cutting plane having the first surface of the third conductive region of the second conductive layer not extending to the reference plane;

the reference and cutting planes being coincident with faces and in a y-z plane.

4. The article of claim 2, wherein a plurality of electrically responsive elements is defined by n unit cells and n−

1 cutting planes, wherein n is at least 3.

5. The article of claim 3, wherein the third surface of the nonconductive layer is adjacent to the fourth surface of the first conductive region of the first conductive layer;

and the fourth surface of the nonconductive layer is adjacent to the third surface of the third conductive region of the second conductive layer.

6. The article of claim 1, wherein the first and second electrically responsive elements each have a cross-section defined by an x-z plane;

the cross-section providing a nonconductive layer having a third and fourth surfaces;

the nonconductive layer in between a first and second conductive layers;

the first conductive layer adjacent to the third surface of the nonconductive layer, and the second conductive layer adjacent to the fourth surface of the nonconductive layer;

the first conductive layer having at least first and second conductive regions having interstices between the conductive regions;

the second conductive layer having at least third and fourth conductive elements having interstices between the conductive regions;

wherein the conductive regions of the first and second conductive layers repeat in the x-dimension.

7. The article of claim 2, wherein the first and second electrically responsive elements repeat in the x-dimension.

8. The article of claim 7, wherein the first and second electrically responsive elements repeat in the x-dimension in a range of 2 to 1000 unit cells.

9. The article of claim 1, wherein n electrically responsive elements are separable by n−

1 cutting planes between adjacent electrically responsive elements, wherein n is at least 3.

10. The article of claim 6, wherein interstices between the conductive regions of the conductive layers comprise a polymeric nonconductive material.

11. The article of claim 3, wherein the polymeric conductive material comprises a polymeric material and organic fillers.

12. The article of claim 11, wherein the polymeric material is selected from the group consisting of polyurethanes, polyolefins, fluorinated polyolefins, polyacrylates, polyacrylonitrile-butyl rubber copolymers, polymethyl methacrylate and combinations thereof.

13. The article of claim 11, wherein the organic fillers are selected from the group consisting of carbon black, carbon nanotubes and combinations thereof.

14. The article of claim 3, wherein the polymeric nonconductive material is selected from the group polyurethanes, polyolefins, fluorinated polyolefins, polyacrylates, polyacrylonitrile-butyl rubber copolymers and combinations thereof.

15. A method of making an article of claim 1 on a continuous medium comprising:

coextruding n electrically responsive elements on a continuous medium;

wherein the adjacent electrically responsive elements extending in the x-dimension are separated by n−

1 cutting planes perpendicular to an x-dimension;

wherein n is at least 2.

16. A method of making an article of claim 1 comprising:

a) providing a first resin to form at least a nonconductive layer having third and fourth opposing surfaces;

b) providing a second resin to form at least two conductive layers;

each of the two conductive layers being adjacent to the third and fourth opposing surfaces of the nonconductive layer; and

c) coextruding the first and second resins;

the first resin providing at least one nonconductive layer that is substantially continuous in the x- and y-dimensions;

the second resin providing at least two conductive layers that are discontinuous in the x-dimension;

the conductive layers each having alternating conductive and nonconductive regions;

the conductive regions having first and second surfaces perpendicular to the third and fourth opposing surfaces of the nonconductive layer;

wherein the first or second surfaces of the conductive regions are coincident to at least one cutting plane;

the cutting plane being perpendicular to the x-dimension.

17. An article having an x-dimension, a y-dimension and a z-dimension, the three dimensions being mutually orthogonal, the article comprising:

a. at least two elastomeric conductive layers extending in the x-dimension, each elastomeric conductive layer comprising alternating elastomeric conductive regions and elastomeric nonconductive regions;

b. at least one elastomeric nonconductive layer; and

wherein the at least two elastomeric conductive layers and the at least one elastomeric

nonconductive layer alternate in the z-dimension

wherein the at least two elastomeric conductive layers and the at least one elastomeric nonconductive layer form at least a first and a second electrically responsive element, wherein the at least one elastomeric nonconductive layer in the first electrically responsive element and the at least one elastomeric nonconductive layer in the second electrically responsive element form a substantially continuous nonconductive layer in the x-dimension;

wherein the at least first and second electrically responsive elements each have two opposing faces coincident with the y-z plane,

wherein the first electrically responsive element comprises a first elastomeric conductive region; and

a third elastomeric conductive region,

wherein the first elastomeric conductive region has a first surface and the third elastomeric conductive region has a second surface,

wherein the first surface of the first elastomeric conductive region is exposed to a first opposing face of the first element and the second surface of the third elastomeric conductive region is exposed to a second opposing face of the first element

wherein the second electrically responsive element comprises a second elastomeric conductive region; and

a fourth elastomeric conductive region,

wherein the second elastomeric conductive region has a first surface and the fourth elastomeric conductive region has a second surface,

wherein the first surface of the second elastomeric conductive region is exposed to a first opposing face of the second element and the second surface of the fourth elastomeric conductive region is exposed to a second opposing face of the second element

wherein the first elastomeric conductive layer comprises the first and second elastomeric conductive regions and the second elastomeric conductive layer comprises the third and fourth elastomeric conductive regions.

18. The article of claim 17, wherein the electrically responsive element is a component of a device selected from the group consisting of actuators, sensors, capacitors and combinations thereof.