JP2014164997A - Organic EL panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an organic EL panel capable of suppressing short-circuiting on electrode wiring sections.SOLUTION: An organic EL panel 10 comprises: a light-emitting section 10a disposed on a support substrate 11 and formed of a first electrode 12, an organic layer 14, and a second electrode 15 laminated in sequence; first electrode wiring sections 16 connected to the first electrode 12; an insulating film 13 which is formed so as to cover ends of the first electrode and part of the first electrode wiring sections; and second electrode wiring sections 17 connected to the second electrode 15. The plurality of first electrode wiring sections 16 and second electrode wiring sections 17 are arranged so as to surround the light-emitting section 10a. The second electrode 15 is formed so that ends thereof overlap with the second electrode wiring sections 17. The organic layer 14 and the second electrode 15 are formed so that ends thereof intersect with each other between the first electrode wiring sections 16 and the second electrode wiring sections 17. The ends of the organic layer 14 protrude to the outside with respect to the ends of the second electrode 15 on the first electrode wiring sections 16.

Description

  The present invention relates to an organic EL (Electro Luminescence) panel.

  Conventionally, an organic EL element known as a self-luminous element formed of an organic material is, for example, an anode made of ITO (Indium Tin Oxide) or the like, an organic layer having at least a light emitting layer, and a non-light made of aluminum (Al) or the like. A light-transmitting cathode is sequentially laminated (see, for example, Patent Document 1).

  Such an organic EL element emits light by injecting holes from the anode and injecting electrons from the cathode, and the holes and electrons recombine in the light emitting layer. In addition to being employed in displays, organic EL elements have also been developed as surface-emitting lighting in recent years.

JP 59-194393 A JP 2010-198980 A

  An organic EL panel used as surface emitting illumination is required to have uniform luminance on the light emitting surface. On the other hand, the anode wiring part (anode feeding part) electrically connected to the anode and the cathode wiring part (cathode feeding part) electrically connected to the cathode are arranged on the side of the support substrate so as to surround the light emitting part. There is known a method of improving the uniformity of luminance by supplying a plurality of currents along a plurality of directions and supplying current to the light emitting unit (see, for example, Patent Document 2).

  In this method, in order to connect the cathode to the cathode wiring portion, the area of the cathode is formed wider than the area of the organic layer so that the end of the cathode is outside the end of the organic layer. In this case, since the end portion of the cathode also overlaps with the anode wiring portion, conventionally, an insulating film is formed so as to cover a part of the anode wiring portion to prevent a short circuit between the cathode and the anode wiring portion. However, when an organic layer is formed by a vacuum evaporation method, a protrusion of about 1.0 μm generated at the edge of the opening of the evaporation mask may come into contact with the insulating film, resulting in a scratch (hole) in the insulating film on the anode wiring portion. In addition, when the cathode is formed after the organic layer is formed, there is a problem that the cathode and the anode wiring portion may be short-circuited through the scratch.

  Then, this invention is made | formed in view of this problem, and it aims at providing the organic electroluminescent panel which can suppress the short circuit on an electrode wiring part.

In order to solve the above-described problems, the present invention provides a support substrate, a light-emitting section that is formed by sequentially stacking a first electrode, an organic layer including at least a light-emitting layer, and a second electrode that are disposed on the support substrate. And an insulating film formed on the support substrate so as to cover the first electrode wiring part connected to the first electrode and the end of the first electrode and a part of the first electrode wiring part. And a second electrode wiring portion disposed on the support substrate and connected to the second electrode, and the first electrode wiring portion and the second electrode wiring portion surround the light emitting portion, respectively. A plurality of organic EL panels arranged,
The second electrode is formed such that an end thereof overlaps the second electrode wiring portion, and the organic layer and the second electrode are between the first electrode wiring portion and the second electrode wiring portion. The organic EL panel is formed so that the ends of the organic layer intersect with each other, and the end of the organic layer protrudes outward from the end of the second electrode on the first electrode wiring portion. .

  Further, the end portion of the organic layer and the end portion of the second electrode intersect at a substantially center between the first electrode wiring portion and the connection portion of the second electrode wiring portion with the second electrode. It is characterized by becoming.

  According to the present invention, it is possible to suppress a short circuit on the electrode wiring portion.

The rear view which shows the organic electroluminescent panel which is embodiment of this invention. Sectional drawing which shows an organic electroluminescent panel same as the above. The figure explaining the manufacturing process of an organic electroluminescent panel same as the above. The figure explaining the manufacturing process of an organic electroluminescent panel same as the above. The figure explaining the manufacturing process of an organic electroluminescent panel same as the above. The figure explaining the manufacturing process of an organic electroluminescent panel same as the above.

  Embodiments to which the present invention is applied will be described below with reference to the accompanying drawings.

  FIG. 1 is a rear view showing an organic EL panel 10 according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view of the organic EL panel 10. In addition, in FIG. 1, the arrangement | positioning location of the sealing member 18 is shown with the dotted line. As shown in FIGS. 1 and 2, the organic EL panel 10 includes a support substrate 11, a first electrode 12 that is a transparent electrode, an insulating film 13, an organic layer 14, and a second electrode 15 that is a reflective electrode. The first electrode wiring portion 16, the second electrode wiring portion 17, and the sealing member 18 are mainly configured. A substantially rectangular region in which the organic layer 14 is sandwiched between the first electrode 12 and the second electrode 15 constitutes a light emitting unit (organic EL element) 10a. When a voltage is applied between the electrodes 12 and 15 via the first electrode wiring part 16 and the second electrode wiring part 17, the light emitting part 10a emits light from the organic layer 14 (the organic light emitting layer). And the light L emitted from the light emission part 10a is radiate | emitted outside from the surface (lower surface in FIG. 2) side of the support substrate 11. FIG. That is, the organic EL panel 10 is a so-called bottom emission type organic EL panel.

  The support substrate 11 is a rectangular substrate made of translucent non-alkali glass, for example. Other glass substrates such as alkali glass may be used, and the glass thickness is not particularly limited. A transparent resin substrate may be used. A first electrode 12, a first electrode wiring portion 16, and a second electrode wiring portion 17 are formed on the back surface (upper surface in FIG. 2) of the support substrate 11, and further, the insulating film 13, the organic layer 14, and the second electrode wiring portion 17 are formed. The electrodes 15 are sequentially stacked. Further, the first electrode wiring portion 16 is electrically connected to the first electrode 12, and the second electrode wiring portion 17 is electrically connected to the second electrode 15.

In the present embodiment, the first electrode 12 serves as an anode for injecting holes, and a transparent conductive material such as ITO or AZO (Aluminum Zinc Oxide) is formed on the support substrate 11 by means of a sputtering method or the like by 50 to 500 nm. The transparent electrode is formed into a layer with a film thickness of and patterned into a predetermined shape by means such as photolithography. The first electrode 12 is formed in the same process using the same transparent conductive material as the first electrode wiring part 16 and the second electrode wiring part 17, and is formed integrally with the first electrode wiring part 16. It is electrically connected to the one-electrode wiring part 16. Moreover, the surface of the first electrode 12, the first electrode wiring portion 16, and the second electrode wiring portion 17 is subjected to surface treatment such as UV / O ₃ treatment or plasma treatment.

  The insulating film 13 covers the peripheral region of the support substrate 11 including the edge (outer region) of the first electrode 12, the inner region of the first electrode wiring part 16, and the inner region of the second electrode wiring part 17, A polyimide-based or phenol-based insulating material is formed into a layer with a film thickness of about 1.0 μm by means such as spin coating, and is patterned into a desired shape by photolithography. The insulating film 13 exposes the central region of the first electrode 12 in a substantially rectangular shape in plan view, and partially exposes the opening 13 a that defines the shape of the light emitting portion 10 a and the inner region of the second electrode wiring portion 17. A substantially L-shaped slit-shaped contact hole portion 13 b that electrically connects the second electrode 15 to the second electrode wiring portion 17. In addition, the contact hole part 13b may be, for example, a plurality of holes formed in a rectangular shape arranged in a substantially L shape.

  The organic layer 14 is composed of a single layer or multiple layers including at least an organic light emitting layer made of an organic material, and is formed on the first electrode 12 with a film thickness of, for example, about 60 to 150 nm. As an example of the multilayer structure, a hole injecting and transporting layer, a first light emitting layer, a second light emitting layer, an electron transporting layer, and an electron injecting layer are sequentially formed from the first electrode 12 side. Note that the light emitting layer may be a single layer or may be a layer that does not include a part of layers even if another layer is added. The organic layer 14 is formed by a vacuum deposition method, and is formed in a desired shape on the back side of the support substrate 11 through a deposition mask having a predetermined opening. The organic layer 14 covers the first electrode 12 and has an end portion between the first electrode 12 and the second electrode wiring portion 17 so as not to contact the second electrode wiring portion 17 via the contact hole portion 13b. It is formed in a substantially rectangular shape in plan view so as to be positioned (see FIGS. 1 and 2B). Further, the organic layer 14 is provided with a protruding portion 14 a that protrudes outward on the first electrode wiring portion 16, and an end portion of the organic layer 14 is between the first electrode wiring portion 16 and the second electrode wiring portion 17. It forms so that it may go outside gradually toward the 1st electrode wiring part 16 from the wiring part 17 (refer FIG.1 and FIG.2 (a)).

  In this embodiment, the second electrode 15 serves as a cathode for injecting electrons. On the organic layer 14, for example, Al, magnesium (Mg), cobalt (Co), Li, gold (Au), copper (Cu). , A reflective electrode made of a conductive film in which a low-resistance conductive material such as zinc (Zn) is formed into a layer having a thickness of 50 to 200 nm. The second electrode 15 is formed by a vacuum deposition method, and is formed in a desired shape on the back side of the support substrate 11 through a deposition mask having a predetermined opening. The second electrode 15 covers the first electrode 12 and is flat so that the end thereof overlaps the inner region of the second electrode wiring portion 17 so as to be in contact with the second electrode wiring portion 17 via the contact hole portion 13b. It is formed in a substantially rectangular shape (see FIGS. 1 and 2B). In addition, the second electrode 15 is provided with a notch 15 a that is recessed inwardly on the first electrode wiring portion 16, and an end thereof is between the first electrode wiring portion 16 and the second electrode wiring portion 17. It forms so that it may gradually go inward toward the 1st electrode wiring part 16 from the two-electrode wiring part 17 (refer FIG.1 and FIG.2 (a)). By forming the organic layer 14 and the second electrode 15 as described above, the end portion of the organic layer 14 and the end portion of the second electrode 15 are connected to the first electrode wiring portion 16 and the second electrode wiring portion 17. And the end portion of the organic layer 14 is projected outward from the end portion of the second electrode 15 on the first electrode wiring portion 16. The reason why the organic layer 14 and the second electrode 15 are formed in such a shape will be described in detail later.

  The first electrode wiring part 16 is an electrode (anode) wiring part formed of the same transparent conductive material as that of the first electrode 12 and the second electrode wiring part 17 in the same process as described above. The first electrode wiring part 16 is electrically connected to the first electrode 12 by being formed integrally with the first electrode 12. The first electrode wiring portion 16 is formed in a substantially rectangular shape in plan view in the substantially central region of each end portion along the four end portions (sides) of the support substrate 11 having a substantially rectangular shape in plan view. A plurality of (four) first electrode wiring portions 16 are arranged on the back surface of the light emitting portion 10a so as to surround the light emitting portions 10a from different directions (four directions).

  The second electrode wiring part 17 is an electrode (cathode) wiring part formed in the same process with the same transparent conductive material as the first electrode 12 and the first electrode wiring part 16 as described above. The second electrode wiring portion 17 is in contact with the second electrode 15 through a contact hole portion 13b formed at a location overlapping the inner region of the second electrode wiring portion 17 of the insulating film 13 and thereby electrically connected to the second electrode 15. Connected. The second electrode wiring portion 17 is formed in a substantially “L” shape in plan view along the four corners of the support substrate 11, and a plurality of (four) second electrode wiring portions are formed on the back surface of the support substrate 11. 17 becomes the appearance arrange | positioned so that the light emission part 10a may be enclosed from a respectively different direction (4 directions). As described above, the first electrode wiring portion 16 and the second electrode wiring portion 17 are connected to the first electrode 12 and the second electrode 15 in a plurality of directions, respectively, so that a current flows from the plurality of directions to the light emitting unit 10a. It is possible to suppress the occurrence of uneven brightness on the light emitting surface due to the resistance of the first electrode 12 or the second electrode 15 and improve the uniformity of the brightness.

  The sealing member 18 is made of, for example, a glass material and is formed in a concave shape by an appropriate method such as molding, sandblasting, cutting, or etching. The sealing member 18 is hermetically disposed on the support substrate 11 via an adhesive 18a made of, for example, an ultraviolet curable epoxy resin, and the light emitting unit 10a is sealed. In a sealing space formed by the support substrate 11 and the sealing member 18, a sheet-like moisture absorbent (not shown) made of, for example, strontium oxide (SrO), calcium oxide (CaO), barium oxide (BaO), or the like is present. Arranged. The sealing member 18 may have a flat plate shape. In this case, the sealing member 18 is disposed on the support substrate 11 via a spacer.

  As described above, the organic EL panel 10 is configured.

  Next, a method for manufacturing the organic EL panel 10 will be described with reference to FIGS.

(First electrode, first electrode wiring part and second electrode wiring part forming step)
First, as shown in FIG. 3, on the back surface of the support substrate 11, the above-mentioned transparent conductive material is formed in a layer shape with a film thickness of 50 to 500 nm by a sputtering method or the like, and then patterned by a photolithography method or the like. The electrode 12, the first electrode wiring part 16, and the second electrode wiring part 17 are formed. Then, surface treatment such as UV / O ₃ treatment or plasma treatment is performed on the surfaces of the first electrode 12, the first electrode wiring portion 16, and the second electrode wiring portion 17.

(Insulating film formation process)
Next, as shown in FIG. 4, the insulating material described above is formed into a layer having a thickness of about 1.0 μm by spin coating or the like, and is patterned by photolithography to form the opening 13a and the contact hole 13b. An insulating film 13 is formed. The insulating film 13 covers the peripheral region of the support substrate 11 including the edge (outer region) of the first electrode 12, the inner region of the first electrode wiring portion 16, and the inner region of the second electrode wiring portion 17.

(Organic layer formation process)
Next, as shown in FIG. 5, a vapor deposition mask M1 having an opening is disposed on the back side of the support substrate 11, and a predetermined organic material is deposited on the back side of the support substrate 11 via the vapor deposition mask M1 by a vacuum vapor deposition method. The organic layer 14 is formed in layers. In FIG. 5, the vapor deposition mask M <b> 1 shows only the opening edge portion with a one-dot chain line. When the organic layer 14 has a multilayer structure, vapor deposition is performed by the number of layers, and the total film thickness of the organic layer 14 is arbitrarily determined by the layer structure or the like. The outer shape of the organic layer 14 is determined by the shape of the opening of the vapor deposition mask M1. In the present embodiment, the opening of the vapor deposition mask M1 has a substantially rectangular shape in plan view, and the first electrode wiring portion is provided on the organic layer 14 to provide a protruding portion 14a protruding outward on the first electrode wiring portion 16. 16 and the second electrode wiring part 17 are formed so as to gradually go outward from the second electrode wiring part 17 toward the first electrode wiring part 16 and the portion overlapping the first electrode wiring part 16 is recessed outward. Has been. A protrusion having a thickness of about 1.0 μm, which is the thickness of the insulating film 13, may be generated at the opening edge of the vapor deposition mask M <b> 1 due to burrs or the like generated when the opening is formed. When this projection comes into contact with the insulating film 13 when it is installed on the back side, scratches (holes) are generated in the insulating film 13. Therefore, the scratch of the insulating film 13 caused by the vapor deposition mask M1 occurs at a position where the opening edge of the vapor deposition mask M1 and the insulating film 13 overlap, that is, outside the organic layer 14.

(Second electrode forming step)
Next, as shown in FIG. 6, a vapor deposition mask M2 having an opening is disposed on the back side of the support substrate 11, and the back surface of the support substrate 11 is deposited on the low resistance conductive material through the vapor deposition mask M2 by a vacuum vapor deposition method. The second electrode 15 is formed on the side in the form of a layer having a thickness of 50 to 200 nm. In FIG. 6, the vapor deposition mask M <b> 2 shows only the opening edge portion with a one-dot chain line. The outer shape of the second electrode 15 is determined by the shape of the opening of the vapor deposition mask M2. In the present embodiment, the opening of the vapor deposition mask M <b> 2 has a substantially rectangular shape in plan view, and is formed so that the edge thereof overlaps with the inner region of the second electrode wiring portion 17. Further, the opening of the vapor deposition mask M <b> 2 is formed between the first electrode wiring portion 16 and the second electrode wiring portion 17 in order to provide the second electrode 15 with a notch 15 a that is recessed inwardly on the first electrode wiring portion 16. Between the second electrode wiring part 17 and the first electrode wiring part 16, the part is formed so as to gradually go outward and to overlap with the first electrode wiring part 16.

  In this way, the end portion of the organic layer 14 and the end portion of the second electrode 15 are connected to each other between the first electrode wiring portion 16 and the second electrode wiring portion 17 by the organic layer forming step and the second electrode forming step. If the end of the organic layer 14 protrudes outside the end of the second electrode 15 on the first electrode wiring section 16, the end of the second electrode 15 is the first electrode wiring section. On 16, it is located on the inner side of the end of the organic layer 14, so that it does not reach the outside of the organic layer 14 where there is a risk of scratching. Therefore, even if the insulating film 13 is scratched by the opening edge of the vapor deposition mask M1 for forming the organic layer 14, it is possible to prevent the second electrode 15 and the first electrode wiring portion 16 from being short-circuited. Can do. In addition, since the intersection of the end portion of the organic layer 14 and the end portion of the second electrode 15 is between the first electrode wiring portion 16 and the second electrode wiring portion 17, even if both are intersected, short circuit or connection It does not cause defects. In consideration of errors in the formation positions of the organic layer 14 and the second electrode 15 by vapor deposition, the intersection between the end portion of the organic layer 14 and the end portion of the second electrode 15 is between the first electrode wiring portion 16. Length W1 and the length W2 between the contact holes 13b are substantially equal (W1 = W2), that is, the connection point between the first electrode wiring portion 16 and the second electrode 15 of the second electrode wiring portion 17 It is desirable to be approximately in the middle. If the crossing point is close to the first electrode wiring part 16, a short circuit may occur due to a formation error where the end of the second electrode 15 is outside the end of the organic layer 14 on the first electrode wiring part 16. This is because, if the contact hole portion 13b is close, the organic layer 14 may overlap the contact hole portion 13b due to a formation error, and the connection between the second electrode 15 and the second electrode wiring portion 17 may be insufficient. The “substantially center” means not only a complete center but also a short circuit between the second electrode 15 and the first electrode wiring part 16 and a connection failure between the second electrode 15 and the second electrode wiring part 17. A position where the difference between the length W1 and the length W2 is small is included.

(Sealing process)
Next, as shown in FIGS. 1 and 2, a concave sealing member 18 is hermetically disposed on the support substrate 11 via an adhesive 18a, for example, in a nitrogen atmosphere to seal the light emitting portion 10a. To do.

  The organic EL panel 10 is manufactured through the above steps.

The organic EL panel 10 includes a support substrate 11, a light emitting unit 10 a that is formed by sequentially stacking a first electrode 12, an organic layer 14 including at least a light emitting layer, and a second electrode 15. A first electrode wiring portion 16 disposed on the substrate 11 and connected to the first electrode 12, and an insulating film formed to cover at least the end portion of the first electrode 12 and a part of the first electrode wiring portion 16 13 and a second electrode wiring part 15 disposed on the support substrate 11 and connected to the second electrode 15 so that the first electrode wiring part 16 and the second electrode wiring part 17 surround the light emitting part 10a. A plurality of organic EL panels arranged in each,
The second electrode 15 is formed so that the end thereof overlaps the second electrode wiring portion 17, and the organic layer 14 and the second electrode 15 are between the first electrode wiring portion 16 and the second electrode wiring portion 17. And the end portions of the organic layer 14 protrude outward from the end portions of the second electrode 15 on the first electrode wiring portion 16.

  According to this, in the organic EL panel 10 in which a plurality of first electrode wiring parts 16 and second electrode wiring parts 17 are arranged so as to surround the light emitting part 10a, a vapor deposition mask M1 for forming the organic layer 14 is formed. Even if the insulating film 13 is scratched by the edge of the opening, the short-circuit between the second electrode 15 and the first electrode wiring portion 16 can be suppressed.

  Moreover, the edge part of the organic layer 14 and the edge part of the 2nd electrode 15 are between the 2nd electrode 15 of the 1st electrode wiring part 16 and the 2nd electrode wiring part 17, and a connection location (contact hole part 13b). It is characterized by crossing at approximately the center.

  According to this, even if an error occurs in the formation position of the organic layer 14 and the second electrode 15, a short circuit between the second electrode 15 and the first electrode wiring portion 16, or the second electrode 15 and the second electrode wiring. Connection failure with the portion 17 is not caused.

  The above description exemplifies the present invention, and it is needless to say that various changes and modifications (including deletion of components) are possible without departing from the scope of the invention. In the present invention, the first electrode 12 may be a cathode and the second electrode 15 may be an anode. Further, a configuration in which a plurality of first electrode wiring portions 16 are provided at corners on the support substrate 11 and a plurality of second electrode wiring portions 17 are provided in a substantially central region at an end portion of the support substrate 11 may be employed. Further, Al, molybdenum (Mo), titanium (Ti), silver on the first electrode wiring portion 16 and the second electrode wiring portion 17 (particularly on the connection portion with an external power source exposed to the outside from the sealing member 18). You may form the auxiliary wiring which consists of a low resistance metal material, such as (Ag), copper (Cu), chromium (Cr), nickel (Ni), or a single layer or these layers of these alloys. Moreover, you may form partially (for example, lattice shape) the auxiliary electrode which consists of the above-mentioned low-resistance metal material or the single layer of these alloys, or laminated | stacked on the 1st electrode 12. The present invention is also applicable to a so-called top emission type organic EL panel that emits light from the back side of the support substrate 11 (the side where the light emitting unit 10a is formed).

  The present invention is suitable for an organic EL panel mainly used for a surface emitting light source.

DESCRIPTION OF SYMBOLS 10 Organic EL panel 11 Support substrate 12 1st electrode 13 Insulating film 14 Organic layer 15 2nd electrode 16 1st electrode wiring part 17 2nd electrode wiring part 18 Sealing member

Claims (2)

A support substrate, a light emitting portion formed by sequentially stacking a first electrode, an organic layer including at least a light emitting layer, and a second electrode disposed on the support substrate; and the first electrode disposed on the support substrate; A first electrode wiring portion to be connected; an insulating film formed to cover at least an end of the first electrode and a part of the first electrode wiring portion; and the second electrode disposed on the support substrate. An organic EL panel comprising: a second electrode wiring portion connected to an electrode; and a plurality of the first electrode wiring portion and the second electrode wiring portion arranged so as to surround the light emitting portion,
The second electrode is formed such that an end thereof overlaps the second electrode wiring portion, and the organic layer and the second electrode are between the first electrode wiring portion and the second electrode wiring portion. The organic EL panel is formed so that the ends of the organic layer intersect with each other, and the end of the organic layer protrudes outward from the end of the second electrode on the first electrode wiring portion. .   The end portion of the organic layer and the end portion of the second electrode intersect at a substantially center between the first electrode wiring portion and the connection portion of the second electrode wiring portion with the second electrode. The organic EL panel according to claim 1, wherein

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