JP4019944B2 - Organic EL display device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an organic EL (electroluminescence) display device in which a display region is partitioned by partition walls and a method for manufacturing the same, and more particularly to an organic EL display device in which a sealing plate or the like is attached via a sealant.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, an organic EL display device having a partition has a laminate in which a lower electrode, an organic layer including a light emitting layer made of an organic EL material, and an upper electrode are sequentially laminated on a substrate. Are formed with a plurality of stripe-shaped partition walls that define an organic layer and an upper electrode and insulate between the defined upper electrodes (see Patent Document 1).
[0003]
In addition, in the case where a color filter is mounted on an organic EL display device via a sealant, the flow of the sealant is made using a red / blue / green color filter layer, a black matrix layer, or an overcoat layer in the color filter. There has been proposed a technique in which an outflow prevention wall for preventing the above is formed (see Patent Document 2).
[0004]
[Patent Document 1]
Japanese Patent Laid-Open No. 9-102393
[Patent Document 2]
Japanese Patent Laid-Open No. 2000-30858
[Problems to be solved by the invention]
The inventor made a prototype of an organic EL display device having the above-mentioned partition and examined it. 6A and 6B are configuration diagrams of an organic EL display device as a prototype, in which FIG. 6A is a schematic plan view, and FIG. 6B is a cross-sectional view taken along line AA in FIG.
[0007]
In this organic EL display device, a laminated body (organic EL layer) 5 formed by sequentially laminating a lower electrode 2, an organic layer 3, and an upper electrode 4 is formed on a substrate 1. Here, a plurality of lower electrodes 2 and upper electrodes 4 are provided, and the lower electrodes 2 and the upper electrodes 4 are arranged in a stripe shape extending in directions orthogonal to each other.
[0008]
The organic layer 3 sandwiched between the electrodes 2 and 4 is patterned in the same stripe shape as the upper electrode 4. And the part of the laminated body 5 where the electrodes 2 and 4 intersect and overlap each other forms a pixel as a light emitting portion, and in this example, a plurality of pixels (laminated body 5) are arranged in a lattice pattern. It is in shape.
[0009]
Here, a plurality of stripe-shaped partition walls 7 are formed on the substrate 1, and the organic layer 3 and the upper electrode 4 are defined by the partition walls 7, and the defined upper electrode 4 is insulated from each other. ing.
[0010]
Such an organic EL display device is generally manufactured as follows. First, the lower electrode 2 and the terminal portions 2a and 2b made of ITO or the like are formed by patterning at predetermined positions on the substrate 1 using a sputtering method, a photolithography method or the like.
[0011]
Next, the pixel separation layer 6 is formed on the substrate 1 and the lower electrode 2 in a portion between the pixels. Further, a partition wall 7 for separating the organic layer 3 and the upper electrode 4 is formed on the pixel separation layer 6 by a photolithography method or the like.
[0012]
Thereafter, the substrate 1 is washed, and an organic layer 3 is deposited on the lower electrode 2 by vacuum deposition or the like, and the upper electrode 4 made of metal or the like is deposited on the organic layer 3 by vacuum deposition or the like. Then, film is formed and laminated.
[0013]
As a result, the organic layer 3 and the upper electrode 4 are laminated in a stripe pattern on the substrate 1 on the lower electrode 2 and the substrate 1 located between the partition walls 7. Thus, the stacked body 5 constituting the lattice-like pixel is formed.
[0014]
Further, although not shown, a sealing plate is prepared, and the substrate 1 and the sealing plate are bonded onto the substrate 1 via a sealing agent at the peripheral portion of the substrate 1 other than the display area. In addition to the sealing plate, a sealing can or the like holding a moisture absorbent inside may be used.
[0015]
By the way, in such an organic EL display device, in the step of bonding to the sealing plate via the sealing agent, the outer peripheral sealing agent comes into contact with the end of the partition wall 7 and is transmitted through the partition wall 7 like a capillary phenomenon. The problem of entering into the display area occurred.
[0016]
In the display area where the sealant entered, the pixel portion adjacent to the partition wall 7 did not emit light. It was found that the sealing agent soaked into the organic layer 3 changed to a non-light emitting region, causing uneven brightness and poor display.
[0017]
Therefore, it is necessary to prevent the sealant from flowing. Here, the outflow prevention wall proposed in Patent Document 2 described above prevents the flow of the sealing agent, but there is a restriction that it cannot be realized unless it has a color filter.
[0018]
Accordingly, in view of the above problems, the present invention provides a display region in which an organic EL display device having a partition wall is attached with a sealing plate or the like through a sealant, and the sealant travels from the end of the partition wall to the partition wall. The purpose is to be able to appropriately prevent intrusion.
[0019]
[Means for Solving the Problems]
In order to achieve the above object, according to the first aspect of the present invention, on the substrate (1), the lower electrode (2), the organic layer (3) including the light emitting layer (3b) made of an organic EL material, the upper electrode ( A laminate (5) is formed by sequentially laminating 4), and a plurality of stripe-shaped partition walls defining an organic layer and an upper electrode and insulating between the defined upper electrodes on the substrate In the organic EL display device in which (7) is formed, a wall member (8) extending in a direction orthogonal to the partition walls covers between the adjacent partition walls outside the ends of the plurality of partition walls. The wall member is provided with a plurality of protrusions (8a), each of which protrudes in the direction toward the outer peripheral edge of the substrate along a direction orthogonal to the direction in which the wall member extends. and said that you are.
[0020]
According to this, since the wall member is interposed between the sealing agent disposed on the periphery of the substrate for bonding the sealing plate or the like and the end of the partition wall, the sealing agent invades in the display area direction. However, the sealing agent can be prevented from contacting the end of the partition wall.
[0021]
Therefore, according to the present invention, when a sealing plate or the like is attached via a sealing agent, the sealing agent can be appropriately prevented from entering the display area from the end of the partition through the partition. it can.
[0022]
Here, the wall member and the end portion of the partition wall may be somewhat separated from each other, but the wall member (8) is integrated with the end portion of each partition wall (7) as in the invention of claim 2. If it is connected to the gap, it is possible to completely eliminate the gap into which the sealing agent enters, which is more effective.
[0023]
Moreover, in invention of Claim 3, a partition (7) and a wall member (8) consist of the same material, It is characterized by the above-mentioned.
[0024]
According to this, as shown in the manufacturing method according to the fourth aspect, since the partition wall can be formed on the wall member at the same time using the material constituting the partition wall, the number of steps can be reduced.
[0025]
That is, the invention according to claim 4 is a manufacturing method for manufacturing the organic EL display device according to any one of claims 1 to 3, wherein the lower electrode (2) is formed on the substrate (1). Then, the wall member (8) is formed simultaneously with the partition wall (7), and subsequently, the organic layer (3) and the upper electrode (6) are formed.
[0026]
The invention according to claim 5 is characterized in that the partition wall (7) and the wall member (8) are formed by photolithography.
[0027]
Further, when the partition wall and the wall member are formed simultaneously, the partition wall and the wall member can be easily formed using the same mask if they are formed by photolithography.
[0028]
In addition, the code | symbol in the bracket | parenthesis of each said means is an example which shows a corresponding relationship with the specific means as described in embodiment mentioned later.
[0029]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments shown in the drawings will be described below. FIG. 1 is a schematic plan view of an organic EL display device S1 according to an embodiment of the present invention, FIG. 2 is a schematic cross-sectional view taken along line AA in FIG. 1, and FIG. It is a schematic sectional drawing in alignment with the BB line. In FIG. 1, various hatchings are given for the sake of convenience for easy identification, but these do not show a cross section.
[0030]
The organic EL display device S1 includes a substrate 1 made of a transparent glass substrate, a resin substrate, or the like. On the substrate 1, an organic layer 3 including an anode 2 as a lower electrode and a light emitting layer 3b made of an organic EL material. A laminate (organic EL layer) 5 is formed by sequentially laminating the cathode 4 as the upper electrode.
[0031]
The arrangement form of the laminated body 5 in this embodiment is as follows. A plurality of anodes 2 and cathodes 4 are provided, and the plurality of anodes 2 and the plurality of cathodes 4 are arranged in stripes extending in directions orthogonal to each other (see FIG. 1). The organic layer 3 sandwiched between the electrodes 2 and 4 is patterned in the same stripe shape as the cathode 4.
[0032]
And the part of the laminated body 5 where the anode 2 and the cathode 4 cross and overlap each other forms a pixel as a light emitting part. In this example, as shown in FIG. A plurality of pixels (laminated body 5) are arranged in a lattice pattern.
[0033]
A portion where a plurality of pixels (stacked body 5) is formed on the substrate 1 is a display area. Here, as shown in FIGS. 2 and 3, a pixel isolation layer 6 made of an electrically insulating insulating film is formed between the stripes of the anode 2 and between the stripes of the organic layer 3 and the cathode 4. .
[0034]
A plurality of partition walls 7 are formed in a stripe shape on a portion of the pixel separation layer 6 located between the stripes of the organic layer 3 and the cathode 4. As a result, each pixel, that is, the stacked body 5 is partitioned and separated by the partition wall 7 formed along the stripe direction of the cathode 4. Specifically, the organic layer 3 and the cathode 4 are defined in a stripe shape by the partition wall 7 and the adjacent cathodes 4 are insulated from each other.
[0035]
Here, the materials and the like of the respective layers 2 to 7 formed on the substrate 1 will be described. First, the anode 2 is a transparent electrode film made of ITO (indium and tin oxide) formed by sputtering or the like and patterned by using a photolithography technique.
[0036]
The organic layer 3 is formed by a vacuum deposition method, and in order from the anode 2 side, a hole transporting layer 3a made of a hole transporting organic material, a hole transporting organic material, and an electron transporting organic material. A light emitting layer 3b made of an organic EL material doped with a fluorescent dye and a electron transport layer 3c made of an electron transporting organic material are laminated.
[0037]
Further, the cathode 4 is formed by vapor deposition of a metal material such as Al. The pixel separation layer 6 is made of an electrically insulating resin material such as photosensitive polyimide, and the partition wall 7 is made of a negative photosensitive resin resist material.
[0038]
Further, an anode terminal 2 a electrically connected to the anode 2 and a cathode 4 are electrically connected to a peripheral portion of the display area on the substrate 1, that is, a non-formed portion of the plurality of pixels (stacked body 5). The cathode terminal 2b thus formed is formed in a stripe shape corresponding to the anode 2 or the cathode 4.
[0039]
These terminal portions 2a and 2b are for connecting the anode 2 and the cathode 4 to an external circuit (not shown), respectively. The anode terminal 2a is configured as a lower electrode terminal portion and the cathode terminal 2b is configured as an upper electrode terminal portion. ing. For example, the terminal portions 2a and 2b and the external circuit are electrically connected using a method such as anisotropic conductive adhesive tape or wire bonding.
[0040]
For example, the anode terminal 2 a is configured as a part of the anode 2 extended to the peripheral portion on the substrate 1, and the cathode terminal 2 b is an ITO formed on the substrate 1 on substantially the same plane as the anode 2. And the like.
[0041]
In the organic EL display device S <b> 1, wall members 8 extending in a direction orthogonal to the direction in which the partition walls 7 extend are formed outside both ends of the plurality of partition walls 7. The wall member 8 is formed so as to surround and cover the adjacent individual partition walls 7.
[0042]
In this example, as a preferred embodiment, the wall member 8 is integrally connected to the end of each partition wall 7, and the wall member 8 is made of the same material as the partition wall 7, such as the above-described negative photosensitive resin resist material. Consists of. The wall member 8 and the end of the partition wall 7 may be slightly separated from each other, and the walls 7 and 8 may be made of different materials.
[0043]
Further, in this example, a protruding portion in which a part of the wall member 8 is protruded toward the outer peripheral end portion of the substrate 1 along a direction orthogonal to the direction in which the wall member 8 extends (that is, the direction in which the partition wall 7 extends). 8a. The reason for providing the protruding portion 8a is to ensure the strength of the wall member 8.
[0044]
Moreover, in this example, the cross-sectional shapes of the partition wall 7 and the wall member 8 are reverse tapered shapes that spread upward from the substrate 1 side, as shown in FIGS. In particular, the reverse-tapered cross-sectional shape of the partition wall 7 is to properly define the organic layer 3 and the cathode 4 in the film forming process of the organic layer 3 and the cathode 4.
[0045]
Although not shown in FIGS. 1 and 2, as shown in FIG. 3, in the organic EL display device S <b> 1 of this example, by covering the substrate 1 with a sealing plate 9 such as metal or glass, The organic layer 3 in the device S1 is prevented from being deteriorated by moisture in the atmosphere.
[0046]
In this case, as shown in FIG. 3, a sealing agent 10 is formed on the terminal portions 2 a and 2 b and on the substrate 1 between the terminal portions 2 a and 2 b in the peripheral portion of the substrate 1, and the substrate 1 is interposed via the sealing agent 10. And the sealing plate 9 are bonded together.
[0047]
Next, the manufacturing method of the above-described organic EL display device S1 will be described with specific examples. First, the anode 2 and the terminal portions 2a and 2b are formed at predetermined positions on the substrate 1 made of a glass substrate (anode forming step). In this example, the anode 2 and the terminal portions 2a and 2b are formed by depositing ITO by sputtering or the like and patterning by normal photolithography.
[0048]
Next, the pixel separation layer 6 is formed on the substrate 1 and the anode 2 in the portion between the pixels (pixel separation layer forming step). In this example, a resin (resist) such as photosensitive polyimide is formed on the entire surface of the substrate 1 by spin coating, and after baking this, the pixel separation layer 6 is formed by exposure and development.
[0049]
Further, a partition wall 7 for separating the organic layer 3 and the cathode 4 is formed on the pixel separation layer 6 by a photolithography method (partition wall forming step). In this example, a negative photosensitive resin resist to be a partition wall 7 is spin-coated on the entire surface of the substrate 1, baked, exposed, and developed to form the partition wall 7.
[0050]
In the formation of the partition wall 7, in this example, the partition wall 7 and the wall member 8 are made of the same material. Therefore, when forming the partition wall 7, the material constituting the partition wall 7 is used to simultaneously form the wall member 8. Can be formed. Specifically, it can be easily formed by photolithography using the same mask having the pattern of the partition wall 7 and the wall member 8.
[0051]
Thereafter, the substrate 1 is washed (substrate washing step), the organic layer 3 is formed on the anode 2 by vacuum deposition or the like (organic layer forming step), and the cathode 4 is formed on the organic layer 3. Are deposited by vacuum deposition or the like (a cathode film forming step).
[0052]
Thereby, on the substrate 1, the organic layer 3 and the cathode 4 are laminated in a stripe shape on the anode 2 and the substrate 1 positioned between the partition walls 7. Thus, the stacked body 5 constituting the lattice-like pixel is formed. Although not shown in FIGS. 1 to 3, the same film as the organic layer 3 and the cathode 4 is actually laminated on the upper surfaces of the partition wall 7 and the wall member 8 by such a film forming method. The
[0053]
Further, the sealing plate 9 is prepared, and the substrate 1 and the sealing plate 9 are bonded to each other on the peripheral portion of the substrate 1 via the sealing agent 10 (sealing plate bonding step). In addition, although the photocuring type or the thermosetting type can be used as the sealing agent 10, in order to further control the thickness of the sealing agent 10, resin beads or the like may be mixed. Thus, the organic EL display device S1 is manufactured.
[0054]
By the way, according to the present embodiment, since the wall member 8 is interposed between the sealing agent 10 disposed in the periphery of the substrate for bonding the sealing plate 9 and the end of the partition wall 7, the display Even if the sealing agent 10 invades in the region direction, the sealing agent 10 can be prevented from contacting the end of the partition wall 7.
[0055]
This will be specifically described with reference to FIGS. 4 is an enlarged plan view in the vicinity of the end of the partition wall 7, and FIG. 5 is a cross-sectional view taken along the line AA in FIG. In FIG. 4 and FIG. 5, the sealant 10 is indicated by hatching.
[0056]
As shown in FIG. 4, in the sealing plate bonding step, the sealing agent 10 may spread toward the end portion of the partition wall 7. In the present embodiment, the spreading sealing agent 10 propagates along the protruding portion 8a of the wall member 8 as a kind of capillary phenomenon as shown in FIG.
[0057]
If the wall member 8 is not present, the sealing agent 10 spreading as shown in FIG. 5 reaches the partition wall 7 as it is and enters the display area. However, in this embodiment, as shown in FIG. 4, the spread sealing agent 10 is blocked by the wall member 8 and does not reach the end of the partition wall 7.
[0058]
Therefore, according to the present embodiment, even when the sealing plate 9 is attached via the sealing agent 10 even if the configuration does not have a color filter, the sealing agent 10 extends from the end of the partition wall 7 to the partition wall 7. Thus, it is possible to appropriately prevent the display area from entering the display area.
[0059]
In the present embodiment, the wall member 8 and the end of the partition wall 7 may be somewhat separated from each other, but as described above, the wall member 8 is integrally connected to the end of each partition wall 7 as described above. If it is made the structure, the clearance gap which the sealing agent 10 penetrate | invades can be eliminated completely, and it is more effective.
[0060]
Moreover, according to the preferable form of this embodiment, since the partition wall 7 and the wall member 8 are made of the same material, the partition wall 7 is formed when the partition wall 7 is formed as shown in the manufacturing method. It can form in the wall member 8 simultaneously using the material to do. Therefore, man-hours can be reduced.
[0061]
In addition, when the partition 7 and the wall member 8 are comprised from another material, both the walls 7 and 8 are formed in another process. At this time, the wall member 8 is appropriately formed before the sealing plate bonding step. In the organic EL display device, the sealing plate 9 may be a color filter.
[Brief description of the drawings]
FIG. 1 is a schematic plan view of an organic EL display device according to an embodiment of the present invention.
FIG. 2 is a schematic cross-sectional view along the line AA in FIG.
FIG. 3 is a schematic cross-sectional view along the line BB in FIG. 1;
FIG. 4 is an enlarged plan view in the vicinity of an end of a partition wall.
5 is a cross-sectional view taken along line AA in FIG.
6A and 6B are configuration diagrams of a conventional organic EL display device having partition walls, where FIG. 6A is a schematic plan view, and FIG. 6B is a schematic cross-sectional view taken along line AA in FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Board | substrate, 2 ... Anode as a lower electrode, 3 ... Organic layer,
4 ... Cathode as upper electrode, 7 ... Partition, 8 ... Wall member.

Claims (5)

On the substrate (1), a lower electrode (2), an organic layer (3) including a light emitting layer (3b) made of an organic EL material, and an upper electrode (4) are sequentially laminated to form a laminate (5). And
In the organic EL display device, on the substrate, a plurality of stripe-shaped partition walls (7) that define the organic layer and the upper electrode and insulate between the defined upper electrodes are formed.
A wall member (8) extending in a direction orthogonal to the partition walls is formed outside the end portions of the plurality of partition walls so as to cover between the adjacent partition walls ,
The wall member is provided with a plurality of projecting portions (8a) each having a part projecting toward the outer peripheral edge of the substrate along a direction orthogonal to a direction in which the wall member extends. An organic EL display device. The organic EL display device according to claim 1, wherein the wall member (8) is integrally connected to an end portion of each partition wall (7). 3. The organic EL display device according to claim 1, wherein the partition wall (7) and the wall member (8) are made of the same material. A manufacturing method for manufacturing the organic EL display device according to any one of claims 1 to 3,
After forming the lower electrode (2) on the substrate (1),
Forming the wall member (8) simultaneously with the partition wall (7);
Subsequently, the organic layer (3) and the upper electrode (6) are formed. 5. The method of manufacturing an organic EL display device according to claim 4, wherein the partition wall (7) and the wall member (8) are formed by a photolithography method.

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