Pixel element substrate, display device, electronic device, and method for manufacturing the pixel element substrate

• US 20050040754A1
• Filed: 07/12/2004
• Published: 02/24/2005
• Est. Priority Date: 08/22/2003
• Status: Active Grant

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Sakurai, Kazunori
• Granted Patent: US 7,202,597 B2
• Time in Patent Office: Days
• US Class Current: 313/500
• CPC Class Codes: G02F 1/1345 Conductors connecting electrodes to cell terminals
• CPC Class Codes: H10K 59/122 Pixel-defining structures or layers, e.g. banks
• CPC Class Codes: H10K 59/1275 Electrical connections of the two substrates

Abstract

To provide a display device that applies a uniform driving voltage to each pixel and prevents light emitting regions from being narrower. In a display device obtained by bonding a pixel element substrate to a driving circuit board having a driving circuit for the plurality of pixel elements, the driving circuit board includes connecting terminals connected to the driving circuit for the plurality of pixel elements on the surface of the driving circuit board facing the pixel element substrate. The pixel element substrate comprises pixel electrodes 112 formed on a transmissive substrate 110, pixel elements 120 formed on the plurality of pixel electrodes such that respective ends of the pixel elements are adjacent to each other, common electrode wiring lines 131 for commonly connecting the other respective ends of the plurality of pixel elements to each other, bank regions 115 for separating the pixel elements from each other to define individual pixel element regions, and individual electrode wiring lines 132 for connecting the connecting terminals of the driving circuit board to the corresponding pixel electrodes of the pixel elements via through-holes formed in the bank regions.

Claims

1. A display device obtained by bonding a pixel element substrate having a plurality of pixel elements arranged thereon to a driving circuit board having a driving circuit for the plurality of pixel elements,

wherein the driving circuit board includes connecting terminals connected to the driving circuit for the plurality of pixel elements on the surface of the driving circuit board facing the pixel element substrate,

wherein the pixel element substrate comprises:

a plurality of pixel electrodes formed on a transmissive substrate, the plurality of pixel elements being formed on the plurality of pixel electrodes such that respective ends of the pixel elements are adjacent to each other;

common electrode wiring lines for commonly connecting the other respective ends of the plurality of pixel elements to each other;

bank regions for separating the pixel elements from each other to define individual pixel element regions; and

a plurality of individual electrode wiring lines for connecting the plurality of connecting terminals of the driving circuit board to the corresponding pixel electrodes of the plurality of pixel elements via through-holes formed in the bank regions.

2. A display device according to claim 1, wherein each of the bank regions has a plurality of stepped portions, the through-holes are formed at the highest portions of the stepped portions, and films of the pixel elements are formed using other stepped portions.

3. A display device according to claim 1, wherein each of the pixel elements comprises an organic electroluminescent element, a liquid crystal display device, or a light emitting diode.

4. A display device according to claim 1, wherein each of the pixel electrodes is a transparent electrode, and

wherein the light emitted from or transmitted through the pixel elements is directed to the pixel element substrate.

5. An electronic apparatus including the display device according to claim 1.

6. A pixel element substrate comprising:

a plurality of pixel electrodes formed on a transmissive substrate;

a plurality of pixel elements formed on the plurality of pixel electrodes such that respective ends of the pixel elements are adjacent to each other;

common electrode wiring lines for commonly connecting the other respective ends of the plurality of pixel elements to each other;

bank regions for separating the pixel elements from each other to define individual pixel element regions; and

a plurality of individual electrode wiring lines for connecting a plurality of external connections formed to correspond to the plurality of pixel electrodes on surfaces of the bank regions to the plurality of pixel electrodes via through-holes formed in the bank regions.

7. A method for manufacturing a pixel element substrate comprising:

a first step of forming a conductive layer capable of transmitting light on a transmissive insulating substrate and patterning the conductive layer to form a plurality of pixel electrodes;

a second step of forming an insulating layer on the plurality of pixel electrodes, and patterning the insulating layer to form a contact hole region and a pixel element forming region on each pixel electrode;

a third step of forming each contact hole region and each pixel element forming region on the insulating layer, forming a bank layer having a first height of a relatively higher value at the periphery of each contact hole region and having a second height of a relatively lower value at the periphery of each pixel element forming region;

a fourth step of forming a pixel element on a pixel electrode of each pixel element forming region; and

a fifth step of forming a conductive layer on the contact hole, the bank layer, and each pixel element, and polishing the conductive layer until a portion of the bank layer having the first height is exposed.

8. A method for manufacturing a pixel element substrate according to claim 7, wherein the third step further comprises the steps of:

forming, on the insulating layer, a first bank layer having the second height, which forms each contact hole region and each pixel element forming region, and

forming a second bank layer having the first height at the periphery of each contact hole region in the first bank layer.

9. A method for manufacturing a pixel element substrate according to claim 7, wherein the pixel element is an organic electroluminescent element.