Multilayer conductive polymer device and method of manufacturing same

• US 6,236,302 B1
• Filed: 11/13/1998
• Issued: 05/22/2001
• Est. Priority Date: 03/05/1998
• Status: Expired due to Fees

• Current Assignee: Bourns Incorporated
• Original Assignee: Bourns Incorporated
• Inventors: Walsh, Denis, Barrett, Andrew Brian
• Primary Examiner(s): Gellner, Michael L..
• Assistant Examiner(s): Lee, Kyung S.
• Application Number:
  US09/191,921
• Time in Patent Office: 921 Days
• Field of Search: 338/22.R, 338/312, 338/313, 338/314, 338/295, 338/328, 338/332
• US Class Current: 338/22.00R
• CPC Class Codes: H01C 1/1406 Terminals or electrodes formed on resistive elements having positive temperature coefficient
• CPC Class Codes: H01C 17/28 adapted for applying terminals
• CPC Class Codes: H01C 7/027 consisting of conducting or semi-conducting material dispersed in a non-conductive organic material
• CPC Class Codes: H01C 7/028 consisting of organic substances

Abstract

An electronic device includes two or more conductive polymer layers sandwiched between two external electrodes and one or more internal electrodes. A three layer device is manufactured by: (1) providing a first laminated substructure comprising a first polymer layer between first and second metal layers, a second polymer layer, and a second laminated substructure comprising a third polymer layer between third and fourth metal layers; (2) forming first and second arrays of isolation apertures in the second and third metal layers, respectively; (3) laminating the first and second substructures to opposite surfaces of the second polymer layer; (4) forming first and second arrays of external electrodes in the first and fourth metal layers, respectively; (5) forming a plurality of first terminals, each connecting an external electrode in the second external electrode array to an electrode-defining area in the second metal layer, and a plurality of second terminals, each connecting an external electrode in the first external electrode array to an electrode-defining area in the third metal array; and (6) singulating the laminated structure into separate devices, each including a first polymer layer between a first external electrode and a first internal electrode, a second polymer layer between first and second internal electrodes, and a third polymer layer between the second internal electrode and a second external electrode. Each device includes a first terminal connecting the first internal electrode to the second external electrode, and a second terminal connecting the second internal electrode to the first external electrode.

Claims

1. An electronic device, comprising

first, second and third parallel planar electrodes;

a first conductive polymer layer between the first and second electrodes;

a second conductive polymer layer between the second and third electrodes;

a first minor metallized area coplanar with the first electrode and separated therefrom by a first isolation gap;

a second minor metallized area coplanar with the third electrode and separated therefrom by a second isolation gap;

a first terminal in physical contact with the first and second minor metallized areas, the first and second conductive polymer layers, and the second electrode; and

a second terminal in physical contact with the first and third electrodes and the first and second conductive polymer layers, and isolated from the second electrode by an internal isolation area filled with conductive polymer material that joins the first and second conductive polymer layers.

2. The electronic device of claim 1, wherein each of the first and second conductive polymer layers has first and second opposed planar surfaces, and wherein the second electrode has first and second opposed surfaces, the first surface of the first conductive polymer layer being in contact with the first electrode and the first minor metallized area, the second surface of the first conductive polymer layer being in contact with the first surface of the second electrode, the first surface of the second conductive polymer layer being in contact with the second surface of the second electrode, and the second surface of the second conductive polymer layer being in contact with the third electrode and the second minor metallized area.

3. The electronic device of claim 1, wherein the first and second isolation gaps are filled with an electrically insulating epoxy resin material.

4. The electronic device of claim 1, wherein the each of the first and second terminals comprises:

a first layer formed of a metal selected from the group consisting of tin, nickel, and copper; and

a second layer formed of solder.

5. An electronic device, comprising

first, second, and third conductive polymer layers, each having first and second opposed planar surfaces;

a first planar electrode in contact with the first surface of the first conductive polymer layer;

a second planar electrode in contact with second surface of the first conductive polymer layer and the first surface of the second conductive polymer layer;

a third planar electrode in contact with the second surface of the second conductive polymer layer and the first surface of the third conductive polymer layer;

a fourth planar electrode in contact with the second surface of the third conductive polymer layer;

a first minor metallized area on the first surface of the first conductive polymer layer, coplanar with the first electrode and separated therefrom by a first isolation gap;

a second minor metallized area on the second surface of the third conductive polymer layer, coplanar with the fourth electrode and separated therefrom by a second isolation gap;

a first terminal in physical contact with the first minor metallized area, the second electrode, the fourth electrode, and the first, second, and third conductive polymer layers, the first terminal being isolated from the third electrode by an internal isolation area filled with conductive polymer material that joins the second and third conductive polymer layers; and

a second terminal in physical contact with the second minor metallized area, the first electrode, the third electrode, and the first, second and third conductive polymer layers, the second terminal being isolated from the second electrode by an internal isolation area filled with conductive polymer material that joins the first and second conductive polymer layers.

6. The electronic device of claim 5, wherein the first and second isolation gaps are filled with an electrically insulating epoxy resin material.

7. The electronic device of claim 5, wherein the each of the first and second terminals comprises:

a first layer formed of a metal selected from the group consisting of tin, nickel, and copper; and

a second layer formed of solder.