Active matrix electroluminescent display devices, and their manufacture

• US 20050127376A1
• Filed: 03/19/2003
• Published: 06/16/2005
• Est. Priority Date: 03/20/2002
• Status: Active Grant

• Current Assignee: Beijing Xiaomi Mobile Software Co., Ltd. (Xiaomi Corp.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Roderick Hector, Jason, Young, Nigel David, Fish, David Andrew, Childs, Mark Jonathan
• Granted Patent: US 7,271,409 B2
• Time in Patent Office: Days
• US Class Current: 257/80
• CPC Class Codes: H10K 59/00 Integrated devices, or assemblies of multiple devices, comprising at least one organic light-emitting element covered by group H10K50/00
• CPC Class Codes: H10K 59/12 Active-matrix OLED [AMOLED] displays
• CPC Class Codes: H10K 59/122 Pixel-defining structures or layers, e.g. banks
• CPC Class Codes: H10K 59/131 Interconnections, e.g. wiring lines or terminals
• CPC Class Codes: H10K 59/86 Series electrical configurations of multiple OLEDs

Abstract

Physical barriers (210) are present between neighbouring pixels (200) on a circuit substrate (100) of an active-matrix electroluminescent display device, particularly with LEDs (25) of organic semiconductor materials. The invention forms these barriers (210) with metal or other electrically-conductive material (240) that serves as an interconnection between a first circuit element (21, 4, 5, 6, 140, 150, 160, T1, T2, Tm, Tg, Ch) of the circuit substrate and a second circuit element (400, 400s, 23), for example, a sensor (400s) of a sensor array supported over the pixel array. The conductive barrier material (240) is insulated (40) at the sides of the barriers adjacent to the LEDs and has an un-insulated top connection area (240t) at which the second circuit element is connected to the conductive barrier material (240).

Claims

1. An active-matrix electroluminescent display device comprising:

a circuit substrate on which an array of pixels is present with physical barriers s between at least some of the neighbouring pixels in at least one direction of the array;

each pixel comprising an electroluminescent element;

the circuit substrate comprising circuitry to which the electroluminescent elements are connected;

the physical barriers comprising conductive material that serves as an interconnection between a first circuit element of the circuit substrate and a second circuit element of the device;

which conductive barrier material is insulated at least at the sides of the barriers adjacent to the electroluminescent elements and has top and bottom connection areas that are un-insulated where the first and second circuit elements are connected to the conductive barrier material.

2. A device according to claim 1, wherein the first circuit element of the circuit substrate is at least one thin-film element of a group comprising:

a conductor layer;

an electrode connection;

a supply line;

an addressing line;

a signal line;

a thin-film transistor;

a thin-film capacitor.

3. A device according to claim 1, wherein the second circuit element is an upper electrode of the electroluminescent element, and the first circuit element is at least one thin-film element of the circuit substrate.

4. A device according to claim 3, wherein each pixel comprises side-by-side sub-pixels with the barriers there-between and with the conductive barrier material connecting the upper electrode of one sub-pixel to the lower electrode of an adjacent sub-pixel, which lower and upper electrodes form the first and second circuit elements.

5. A device according to claim 1 or claim 2, wherein an array of sensors is integrated together with the array of pixels, and the sensors provide the second circuit elements that are connected by the conductive barrier material to the first circuit element of the circuit substrate.

6. A device according to any one of the preceding claims, wherein an array of sensors is integrated together with the array of pixels, the circuit substrate comprises matrix addressing circuitry for both the array of pixels and the array of sensors, and the conductive barrier material connects sensors of the array to the matrix addressing circuitry.

7. A device according to claim 5 or claim 6, wherein the sensor array is supported on top of the barriers and over the pixel array.

8. A device according to claim 7, wherein a planarising layer is present over the pixel array with a thickness that extends to the top of the barriers to support the sensor array over the pixel array.

9. A device according to any one of the preceding claims, wherein insulated lengths of the barriers are predominantly of the conductive barrier material (and preferably comprising metal).

10. A device according to any one of the preceding claims, wherein the barrier comprises a metal core which provides the conductive barrier material that is connected with the first circuit element and that has an insulating coating on at least its sides.

11. A device according to any one of claims 1 to 9, wherein the barrier comprises a metal coating which provides the conductive barrier material that is connected with the first circuit element and that has an insulating coating on at least its sides.

12. A device according to any one of claims 1 to 8, wherein the physical barrier is predominantly of insulating material through which vias extend for connection with the circuit element in the circuit substrate, and wherein a metal coating that provides the conductive barrier material extends on top of the physical barrier and in the vias through the physical barrier.

13. A device according to any one of the preceding claims, wherein the electroluminescent element is a current-driven light-emitting diode of organic semiconductor material.

14. A device according to any one of the preceding claims, wherein, under the conductive barrier material, connection windows are present in an intermediate insulating layer on the circuit substrate to permit connection to the first circuit element.

15. A method of manufacturing an active-matrix electroluminescent display device according to any one of the preceding claims, including the steps of:

(a) forming the physical barriers with electrically-conductive material that is deposited on electrode connections to the first circuit element of the circuit substrate and with insulation at least at the sides of the physical barriers adjacent to the pixel areas, the physical barriers having an un-insulated top connection area to the conductive barrier material at the top of the barriers;

(b) providing at least part of the electroluminescent elements in the pixel areas in between the physical barriers; and

(c) providing the second circuit element in connection with the conductive barrier material at the un-insulated top connection area of the barriers.

16. A method according to claim 15, wherein the insulation comprises an insulating coating that is deposited on at least the sides and top of the conductive barrier material and that is subsequently etched from the top connection area.

17. A method according to claim 15, wherein the conductive barrier material comprises aluminium, and the insulation comprises an insulating coating that is formed on the sides of the aluminium barrier material by anodisation, while masking the top connection area against anodisation.

18. A method according to claim 15, wherein the step (a) involves forming the physical barrier predominantly of insulating material through which vias are formed for connection with the circuit element at the connection windows on the circuit substrate, and wherein the electrically-conductive material is deposited as a conductive coating on top of the physical barrier and in the vias through the physical barrier.

19. A method according to claim 18, wherein the conductive coating for the physical barrier and an upper electrode of the electroluminescent element are deposited simultaneously and are separated by a shadow-masking effect of an overhang shape in the side of the physical barrier.