Organic EL display panel for reducing resistance of electrode lines

Abstract

Method for fabricating an organic EL display panel having an EL region at every cross of first and second electrodes, including the steps of forming a plurality of first electrodes at regular intervals on a transparent substrate, forming an insulating later in regions other than the EL regions, forming second supplementary electrodes on the insulating layer, forming an electric insulating barrier between adjacent EL regions perpendicular to the first electrodes, forming an organic EL layer in each of the EL regions with a shadow mask, depositing an electrode material on an entire surface inclusive of the organic EL layer, to form a plurality of second electrodes, and forming a protection film on an entire surface inclusive of the second electrodes.

Claims

1. An organic EL display comprising: a substrate having an EL region; an anode on the EL region of the substrate; a supplementary electrode coupled to a portion of the anode; an insulating layer provided in regions other than the EL region, the insulating layer being contiguous and vertically spaced away from the substrate; an organic EL layer on the EL region; a cathode on the organic EL layer; and a plurality of pads on the substrate at a location proximate to the anode, wherein: the insulating layer includes a first projection part and a second projection part, the first projection part projecting between adjacent ones of the pads, and the second projection part extending from a first side of the EL region.

2. The organic EL display of claim 1, wherein a lower surface of the supplementary electrode is coupled to an upper surface of the anode.

3. The organic EL display of claim 1, wherein the supplementary electrode has resistance lower than that of the anode.

4. The organic EL display of claim 1, further comprising a second supplementary electrode on the insulating layer, wherein the supplementary electrode is a first supplementary electrode.

5. The organic EL display of claim 4, wherein the second supplementary electrode includes a first supplementary projection part and a second supplementary projection part.

6. The organic EL display of claim 5, wherein the first supplementary projection part is between the first projection part of the insulating layer, and the second supplementary projection part is on the second projection part of the insulating layer at a corner area of the EL region.

7. The organic EL display of claim 1, wherein the anode includes at least indium tin oxide (ITO), and the supplementary electrode includes at least Ag.

8. The organic EL display of claim 1, wherein the second projection part is at a corner area of the EL region.

9. The organic EL display of claim 1, wherein the second projection part extends from the first side of the EL region toward an interior area of the EL region.

10. The organic EL display of claim 1, wherein the second projection part extends from a second side of the EL region toward an interior area of the EL region.

11. An organic EL display comprising: a substrate having an EL region; a first electrode on the EL region of the substrate; an insulating layer provided in regions other than the EL region, the insulating layer being contiguous and vertically spaced away from the substrate; an organic EL layer on the EL region; a second electrode on the organic EL layer; a plurality of pads on the substrate at a location proximate to the first electrode; and a supplementary electrode coupled to an end portion of the first electrode or the second electrode, wherein: the insulating layer includes a first projection part and a second projection part, the first projection part projecting between adjacent ones of the pads, and the second projection part extending from a first side of the EL region.

12. An organic EL display comprising: a substrate having an EL region; a first electrode on the EL region of the substrate; a supplementary electrode coupled to a portion of the first electrode; an insulating layer at regions of the substrate other than the EL region, the insulating layer being contiguous and vertically spaced away from the substrate; an organic EL layer on the EL region; a second electrode on the organic EL layer; and a plurality of pads on the substrate at a location proximate to the first electrode, wherein: the insulating layer includes a first projection part and a second projection part, the first projection part projecting between adjacent ones of the pads, and the second projection part extending from a first side of the EL region.

13. The organic EL display of claim 12, wherein one of the first or second electrode is a cathode and the other one of the first or second electrode is an anode, and wherein the cathode includes at least Ag.

14. The organic EL display of claim 13, wherein a protection layer is provided over the cathode.

15. The organic EL display of claim 12, wherein an insulating barrier is provided between adjacent light emitting elements.

16. The organic EL display of claim 12, wherein the organic EL display is encapsulated.

17. The organic EL display of claim 12, wherein the supplementary electrode has a smaller dimension than the first electrode.

18. The organic EL display of claim 12, further comprising a second supplementary electrode coupled to a portion of the second electrode, wherein the supplementary electrode is a first supplementary electrode.

19. The organic EL display of claim 18, wherein the second supplementary electrode includes a first supplementary projection part and a second supplementary projection part, the first supplementary projection part being between the first projection part of the insulating layer, and the second supplementary projection part being on the second projection part of the insulating layer at a corner area of the EL region.

20. The organic EL display of claim 12, wherein the second projection part is at a corner area of the EL region and extends from the first side of the EL region toward an interior area of the EL region and extends from a second side of the EL region toward the interior area of the EL region.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principle of the invention. In the drawings;

(2) FIG. 1 illustrates a section showing a related art method for fabricating an organic EL display panel;

(3) FIG. 2 illustrates a plan view of a shadow mask employed in FIG. 1;

(4) FIGS. 3A˜3G illustrate perspective views each showing the steps of a method for fabricating an organic EL display panel in accordance with a preferred embodiment of the present invention;

(5) FIGS. 4A˜4G illustrate plan views each showing the steps of a method for fabricating an organic EL display panel in accordance with a preferred embodiment of the present invention;

(6) FIG. 5A illustrates a section across a line I-I in FIG. 4G; and

(7) FIG. 5B illustrates a section across a line II-II in FIG. 4G.

DETAILED DESCRIPTION

(8) Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. FIGS. 3A˜3G illustrate perspective views each showing the steps of a method for fabricating an organic EL display panel in accordance with a preferred embodiment of the present invention, and FIGS. 4A˜4G illustrate plan views each showing the steps of a method for fabricating an organic EL display panel in accordance with a preferred embodiment of the present invention.

(9) Referring to FIGS. 3A and 4A, first electrodes 11 and pads 11-2 of second electrodes are formed of transparent material on a transparent substrate 10.

(10) Then, referring to FIGS. 3B and 4B, for reducing resistance of the first electrodes 11, a first supplementary electrode 11-1 is formed such that a part of the first supplementary electrode 11-1 is overlapped with an edge of each of the first electrodes 11. The first supplementary electrode 11-1 is formed of a metal that has a resistance relatively lower than ITO of the first electrode 11, such as Cr, Al, Cu, W, Au, Ni, and Ag.

(11) Referring to FIGS. 3C and 4C, an insulating layer 12 is formed in region except an EL region. The insulating layer 12 may be formed of any organic or inorganic material, as far as the material is insulator.

(12) Referring to FIGS. 3D and 4D, a second supplementary electrodes 13 are formed on the insulating layer 12. Each of the second supplementary electrodes 13 has a projected part 13-1 in the vicinity of the edge of the EL region so as to be in contact with each of the second electrodes, electrically. The second supplementary electrode 13 to be in contact with each of the second electrodes is formed of a metal having a resistance lower than the second electrodes relatively, such as Cr, Al, Cu, W, Au, Ni, and Ag.

(13) Referring to FIGS. 3E and 4E, a buffer layer (not shown) is formed between adjacent EL regions in a direction perpendicular to the first electrode 11, and an electric insulating barrier on each of the buffer layers.

(14) Referring to FIGS. 3F and 4F, an organic EL layer 16 is formed in each of the EL regions with a shadow mask 15 having a plurality of via holes 15-1. The via holes 15-1 in the shadow mask 15 are in conformity with the EL regions.

(15) Then, referring to FIGS. 3G and 4G, an electrode material is deposited on an entire surface inclusive of the organic EL layer, to form a plurality of second electrodes 17 electrically connected to the second supplementary electrodes 13, respectively.

(16) Though not shown, a protection film is formed on an entire surface inclusive of the second electrode 17, and an encapsulation is carried out, to finish fabrication of the organic EL display panel. The first electrode is an anode and the second electrode is cathode.

(17) FIG. 5A illustrates a section across a line I-I in FIG. 4G, and FIG. 5B illustrates a section across a line II-II in FIG. 4G.

(18) Referring to FIGS. 5A and 5B, the organic EL display panel of the present invention has an EL region at every cross of the first electrodes 11 and the second electrodes 17.

(19) Moreover, the electric insulating barrier 14, formed on each of the buffer layers 18 between adjacent EL regions, insulates the second electrodes 17 from each other, electrically.

(20) Furthermore, the second supplementary electrode 13, formed around each of the EL regions, is connected to each of the second electrodes 17, electrically. Each of the second electrodes 17 is connected to one of the projected parts 13-1 of the second supplementary electrodes 13.

(21) Thus, since the second supplementary electrode can reduce a resistance of the second electrode (cathode), an efficiency of the organic EL display can be improved, and a power required for operating the organic EL display can be reduced, to reduce waste of power.

(22) It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.