KR20160016800A - Display device - Google Patents

Abstract

A display device (1) including a reversely tapered partition wall, the display device (1) being capable of reducing the thickness of the second electrode. The display device 1 includes a substrate 2, a plurality of organic electroluminescent elements formed in the display region 30 on the substrate, a region where the organic electroluminescent elements are formed, and barrier ribs And a plurality of organic electroluminescent elements, wherein the plurality of organic electroluminescent elements comprises a first electrode, a second electrode formed apart from the first electrode, and a second electrode formed between the first electrode and the second electrode, And the second electrode has a connecting portion extending over the barrier from the display region to the contact hole and the end portion of the barrier rib on the substrate side has an obtuse angle formed by the side face of the barrier rib and the bottom face of the barrier rib in the display region, In the region where the contact hole is formed, an angle formed by the side face of the partition wall and the bottom face of the partition wall is an acute angle.

Description

Display device {DISPLAY DEVICE}

The present invention relates to a display device and a method of manufacturing the same.

As one of display devices, a display device using an organic electroluminescent device (hereinafter referred to as organic EL device) as a light source of a pixel is known. For example, in a color display device, three kinds of organic EL elements are formed as light sources of pixels. That is, (1) a red organic EL element for emitting red light, (2) a green organic EL element for emitting green light, and (3) a blue organic EL element for emitting blue light are formed on a substrate .

On the substrate, a partition wall defining an area where the organic EL element is formed is usually formed. As such a partition, for example, a lattice-shaped partition wall is formed. The three kinds of organic EL elements are arranged in a matrix in a region surrounded by the barrier ribs.

10 is a cross-sectional view schematically showing an organic EL element constituting a pixel.

As shown in Fig. 10, the partitions are roughly divided into so-called net taper-shaped partitions and reverse tapered partitions. The net tapered barrier ribs are formed such that the angle formed between the side surface of the barrier rib defining the recess and the bottom surface of the barrier rib is an acute angle when a region including a recess defined by the barrier rib is cut in a plane extending in the thickness direction of the barrier rib. will be. The reverse tapered barrier ribs are formed so that the angle formed between the side surface of the barrier rib defining the recess and the bottom surface of the barrier rib is an acute angle when a region including the recess defined by the barrier rib is cut in a plane extending in the thickness direction of the barrier rib. will be. 10 shows a reverse tapered shape, that is, a partition wall 51 having an obtuse angle formed by the side surface of the partition and the bottom surface of the partition.

Each organic EL element 52 includes a first electrode 53 and one or a plurality of organic EL layers (a first organic EL layer 54 and a second organic EL layer 55 ), And a second electrode 56 in this order.

The first organic EL layer 54 and the second organic EL layer 55 are formed by, for example, a coating method. More specifically, the ink containing the material constituting the first organic EL layer 54 and the second organic EL layer 55 is applied to a region surrounded by the partition wall 51 and is formed by solidifying the ink.

The ink applied to the region surrounded by the partition 51 may be repelled from the surface of the first electrode 53 or from the surface of the partition 51. [ As described above, when ink is repelled from the surface of the first electrode 53 or the surface of the partition wall 51, defects such as vacancies are formed in the first organic EL layer 54 and the second organic EL layer 55 May occur.

When the reverse tapered partition 51 is used, the occurrence of such a problem can be suppressed. In the case where the reverse tapered barrier rib 51 is used, the vicinity of the portion where the side surface of the partition 51 is in contact with the surface of the first electrode 53 is configured such that the distance from the tip portion 57, So that a capillary phenomenon occurs at the tip end portion 57. The capillary phenomenon causes the ink to spread over the entire region surrounded by the barrier ribs 51 to prevent the occurrence of defects in the first organic EL layer 54 and the second organic EL layer 55 See Patent Document 1).

Japanese Patent Application Laid-Open No. 2007-227289

The organic EL element 52 emits light by applying a voltage between the first electrode 53 and the second electrode 56. [ Therefore, it is necessary to electrically connect the first electrode 53 and the second electrode 56 to an external power source.

The first electrode 53 is electrically connected to an external power source through a circuit formed in the substrate 58, for example.

On the other hand, the second electrode 56 is electrically connected to an external power source through, for example, a wiring formed on the partition 51.

Figs. 11 and 12 are cross-sectional views schematically showing a contact region.

11, specifically, the second electrode 56 includes a connecting portion 61 extending over the partition wall from a display region where a plurality of organic EL elements are formed to a contact region outside the display region, And an electrode wiring 63 formed on the substrate, and is connected to an external power source.

The above-described barrier rib 51 is formed not only to define the region where the organic EL element is formed, but also to define the contact hole formed outside the display region. The partition 51 defining the area where the organic EL element is formed and the partition 51 defining the contact hole are collectively formed in the same step by, for example, a photolithography process. The contact portion 61 extending over the barrier rib 51 and the contact conductor 62 formed in the contact hole are collectively formed when the second electrode 56 is formed.

When the connection portion 61 and the contact conductor 62 are formed by the same process as the second electrode 56 as described above, the connection portion 61 and the contact conductor 62 have the same thickness as the second electrode 56 .

Therefore, if the second electrode 56 (connection portion 61) having a thinner thickness is formed by a deposition method or the like, there is a fear that disconnection occurs in the contact region as shown in Fig.

In order to prevent disconnection in this contact region, it is necessary to make the thickness of the second electrode 56 (that is, the thickness of the connecting portion 61) larger. When the thickness of the second electrode 56 is increased, the time required for forming the electrode is increased, and the damage to the light emitting layer or the like at the time of forming the electrode is increased. The first organic EL layer 54 and the second organic EL layer 55 are formed in the region surrounded by the partition 51 in the display region even if the second electrode 56 having a small thickness is formed Therefore, occurrence of disconnection can be avoided.

Therefore, an object of the present invention is to provide a display device in which a thickness of a second electrode (upper electrode) 56 can be made thinner in a display device having a barrier rib 51 having an inverted taper shape.

The present invention provides the following [1] to [4].

[1]

A plurality of organic electroluminescent elements formed in a display region on the substrate,

And a barrier rib defining a contact hole formed outside the display region, wherein the barrier rib is formed in a region where the plurality of organic electroluminescent elements are formed,

Wherein the plurality of organic electroluminescent elements comprise a first electrode, a second electrode formed to be spaced from the substrate with respect to the first electrode, and a second electrode formed between the first electrode and the second electrode, An organic electroluminescent layer,

The second electrode has a connection portion extending from the display region to the contact hole over the partition wall,

Wherein an end of the barrier rib on the substrate side has an obtuse angle formed by the side surface of the barrier rib and the bottom surface of the barrier rib in the display region and the side surface of the barrier rib and the bottom surface of the barrier rib in the region where the contact hole is formed And the angle formed is an acute angle.

[2] The display device according to [1], wherein an end portion of the partition opposite to the substrate side is formed by an acute angle formed by a side surface of the partition and a bottom surface of the partition in the display region.

[3] The display device according to [1] or [2], wherein the surface of the second electrode on the substrate side is spaced apart from the substrate as coming closer to the partition wall from the central portion of the organic electroluminescent device.

[4] A method of manufacturing a display device according to any one of [1] to [3]

A step of applying a solution of a negative-type photosensitive resin on a substrate to form a coating film for forming a barrier rib,

Forming the barrier ribs by exposing and developing the barrier rib formation coating film with different exposure amounts in the regions where the display region and the contact holes are formed

And a step of forming the display device.

According to the present invention, in a display device having a reverse tapered partition, the thickness of the second electrode (upper electrode) can be made thinner.

1 is a schematic plan view of a display device.
2 is a plan view schematically showing a part of the display area.
3 is a cross-sectional view schematically showing a region where one organic EL element is formed in the display region.
4 is a cross-sectional view of the contact region cut in a plane orthogonal to the column direction Y. Fig.
FIG. 5A is a schematic cross-sectional view of a display device during formation to illustrate a method of manufacturing the display device. FIG.
5B is a schematic cross-sectional view of a display device during formation, which is shown for explaining a manufacturing method of the display device.
5C is a schematic cross-sectional view of a display device during formation to illustrate a method of manufacturing the display device.
6A is a schematic cross-sectional view of a display device during formation to illustrate a method of manufacturing the display device.
FIG. 6B is a schematic cross-sectional view of a display device during formation to illustrate a method of manufacturing the display device.
6C is a schematic cross-sectional view of a display device during formation to illustrate a method of manufacturing the display device.
FIG. 7A is a schematic cross-sectional view of a display device during formation to illustrate a method of manufacturing the display device. FIG.
7B is a schematic cross-sectional view of a display device during formation to illustrate a method of manufacturing the display device.
7C is a schematic cross-sectional view of a display device during formation to illustrate a method of manufacturing the display device.
8A is a schematic cross-sectional view of a display device during formation to illustrate a method of manufacturing the display device.
8B is a schematic cross-sectional view of a display device during formation to illustrate a method of manufacturing the display device.
9 is a schematic plan view of the display device.
10 is a cross-sectional view schematically showing a pixel.
11 is a cross-sectional view schematically showing the contact region.
12 is a cross-sectional view schematically showing a contact region.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, each figure is merely a schematic representation of the shape, size, and arrangement of components so that the invention can be understood. The present invention is not limited by the following description, and each component can be appropriately changed without departing from the gist of the present invention. In the drawings used in the following description, the same constituent elements are denoted by the same reference numerals, and redundant explanations may be omitted.

A display device of the present invention includes a substrate, a plurality of organic EL elements formed in a display region on the substrate, and barrier ribs defining a region where the plurality of organic EL elements are formed and a contact hole formed outside the display region Wherein the plurality of organic EL elements comprise a first electrode, a second electrode formed so as to be apart from the substrate relative to the first electrode, and a second electrode formed between the first electrode and the second electrode, Wherein the first electrode has a plurality of organic EL layers and the second electrode has a connection portion extending from the display region to the contact hole over the barrier ribs, The angle formed by the bottom face of the partition wall is an obtuse angle and the angle formed by the side face of the partition wall and the bottom face of the partition wall in the region where the contact hole is formed is A display which is a device.

The display device mainly includes an active matrix drive type device and a passive matrix drive type device. The present invention can be applied to both types of display devices. In this embodiment, a configuration example applied to an active matrix drive type display device is described as an example.

≪ Configuration Example of Display Apparatus >

First, the configuration of the display device will be described with reference to Figs. 1 to 4. Fig. 1 is a plan view of a display device. 2 is a plan view schematically showing a part of the display area. 3 is a schematic sectional view showing a region in which one organic EL element is formed in the display region. 4 is a schematic cross-sectional view when the contact region is cut into a plane orthogonal to the column direction Y. Fig.

1 to 4, a display device 1 includes a substrate 2, a plurality of organic EL elements 4 formed in a display region 30 set in the substrate 2, And a partition 3 defining a display area 30 in which the organic EL element 4 is formed and defining a contact hole formed outside the display area 30.

As shown in Fig. 1, a display region 30 and a contact region 31 are set on the substrate 2. In Fig.

As shown in Fig. 2, a plurality of organic EL elements 4 (pixels) are formed in the display region 30. Fig. In the present embodiment, the barrier ribs 3 are formed on the substrate 2 so as to cover the regions except for the display region 30 and the contact regions 31. [

In the present embodiment, the barrier ribs 3 are formed in a lattice shape in the display region 30. [ In another embodiment, for example, the partition wall 3 is formed in a stripe shape in the display area 30. [

The organic EL elements 4 are each formed in a region surrounded by the lattice-shaped partitions 3.

On the substrate 2, a plurality of recesses 5 defined by the partition 3 and the substrate 2 are set. A plurality of organic EL elements 4 are formed in each of the plurality of recesses 5.

Since the partition wall 3 of the present embodiment is formed in a lattice shape, when viewed from one side of the thickness direction Z of the substrate 2 (hereinafter sometimes referred to as " planar view "), the plurality of concave portions 5 Are arranged in a matrix form. That is, the plurality of concave portions 5 are formed so as to be aligned at a predetermined interval in the row direction X and at a predetermined interval even in the column direction Y. The shape of the plane of each of the plurality of concave portions 5 is not particularly limited. For example, the concave portion 5 can be formed into a substantially rectangular shape or a substantially elliptical shape in plan view. In the present embodiment, a plurality of concave portions 5, which are substantially rectangular in plan view, are formed. In the present specification, the "row direction X" and the "column direction Y" are orthogonal to the thickness direction Z of the substrate and perpendicular to each other.

In the case where the stripe-shaped barrier ribs 3 are formed as another embodiment, the barrier ribs 3 are arranged so that a plurality of partition members, for example, extending in the row direction X are aligned in the column direction Y at predetermined intervals. In this embodiment, stripe-shaped concave portions 5 are defined by the stripe-shaped partition walls 3 and the substrate 2.

3, the end 3a of the partition 3 on the substrate 2 side is divided by the partition 3 into a plane extending in the thickness direction of the partition 3 in the display area 30 The angle? 1 formed by the side surface of the partition 3 defining the recess 5 and the bottom surface of the partition 3 is formed to be an obtuse angle when the region including the concave portion 5 to be defined is cut. The end portion 3a is formed in such a manner that the width of the cross section when the partition 3 extending in the column direction Y is cut into a plane perpendicular to the extending direction (the column direction Y) .

In the display area 30, the angle? 1 formed by the side surface of the partition 3 and the surface of the substrate 2 (the bottom surface of the partition 3), that is, the inclination angle? 1 of the side surface of the partition 3 is about 95 to about 170 , And 100 deg. To 120 deg. Is preferable. The partition 3 having an angle of inclination θ1 of 0 ° to 90 ° of the side surface of the partition 3 is called a so-called net tapered partition and the inclination angle θ1 of the side surface of the partition 3 is 90 ° to 180 ° Is called a so-called reverse tapered partition wall. That is, in the present embodiment, the display region 30 is provided with the reverse tapered partition 3.

The end 3b of the partition 3 on the side opposite to the substrate 2 has an acute angle formed by the side face of the partition 3 and the bottom face of the partition 3 in the display area 30 . That is, the barrier ribs 3 are not formed in an inverted taper shape from the end 3a on the substrate 2 side to the end 3b on the side opposite to the substrate 2 side, It is preferable that the end 3a of the electrode 2 is formed in an inverted tapered shape and is formed in a net taper shape at the end 3b on the side opposite to the substrate 2 side. By such a shape, disconnection of the second electrode 10 in the boundary region between the barrier rib 3 and the organic EL layers 7 and 9 can be more effectively prevented.

The organic EL element 4 is formed in the partition defined by the partition 3 and the substrate 2 (i.e., the recess 5). When the lattice-shaped barrier ribs 3 are formed as in the present embodiment, the plurality of organic EL elements 4 are formed in the plurality of recesses 5, respectively. That is, the organic EL elements 4 are arranged in a matrix in the same manner as the concave portions 5, and arranged on the substrate 2 at predetermined intervals in the row direction X, As shown in Fig.

In the case where stripe-shaped barrier ribs are formed as another embodiment, the organic EL elements 4 are arranged in the recesses 5 extending in the row direction X so as to be aligned at predetermined intervals in the row direction X, respectively.

In this embodiment, three types of organic EL elements 4 having a luminescent color are formed. (2) a green organic EL element 4G that emits green light; and (3) a blue organic EL element 4G that emits blue light. The red organic EL element 4R emits red light, 4B are formed.

As shown in Fig. 2, these three kinds of organic EL elements 4 (red organic EL element 4R, green organic EL element 4G, and blue organic EL element 4B) The red organic EL device 4R, the green organic EL device 4G and the blue organic EL device 4B can be obtained by repeatedly arranging the row (I), the row (II) and the row (III) Are aligned.

(I) A row in which the red organic EL devices 4R are arranged so as to be aligned at predetermined intervals in the row direction X, respectively.

(II) A row in which the green organic EL elements 4G are arranged so as to be aligned at predetermined intervals in the row direction X, respectively.

(III) A row in which the blue organic EL devices 4B are arranged so as to be aligned at predetermined intervals in the row direction X, respectively.

As another embodiment, in addition to the above three kinds of organic EL elements 4, for example, an organic EL element for emitting white light may be further formed. Further, by forming only one organic EL element 4, a monochrome display device can be realized.

The organic EL element 4 includes a first electrode 6, a second electrode 10 formed so as to be separated from the substrate 2 more than the first electrode 6, the first electrode 6, And one or a plurality of organic EL layers formed between the second electrodes 10. In this specification, one or a plurality of layers formed between the first electrode 6 and the second electrode 10 are referred to as organic EL layers, respectively. The organic EL element 4 has at least one luminescent layer as an organic EL layer. The organic EL element 4 may further include an organic EL layer different from the light emitting layer in addition to the one light emitting layer. For example, a hole injecting layer, a hole transporting layer, an electron blocking layer, an electron transporting layer, and an electron injecting layer are formed as an organic EL layer between the first electrode 6 and the second electrode 10. In addition, two or more light emitting layers may be formed between the first electrode 6 and the second electrode 10.

The organic EL element 4 is a pair of electrodes including an anode and a cathode and includes a first electrode 6 and a second electrode 10. One of the first electrode 6 and the second electrode 10 is formed as an anode and the other electrode is formed as a cathode.

In the present embodiment, as an example of the organic EL element, a first electrode 6 functioning as an anode, a first organic EL layer 7 serving as a hole injection layer, a second organic EL layer 9 serving as a light- And the second electrode 10 functioning as a cathode are laminated on the substrate 2 in this order will be described.

In this embodiment, three kinds of organic EL elements are formed, but they have different configurations of the second organic EL layer 9 which is a light emitting layer. The red organic EL device 4R has a red light emitting layer 9R for emitting red light and the green organic EL device 4G has a green light emitting layer 9G for emitting green light, (4B) has a blue light-emitting layer 9B that emits blue light.

In the present embodiment, the first electrode 6 is formed for each organic EL element 4. [ That is, a plurality of first electrodes 6 of the same number as that of the organic EL element 4 are formed on the substrate 2. The first electrodes 6 are formed corresponding to the arrangement of the organic EL elements 4 and arranged in a matrix so as to overlap with the first organic EL layer 7 and the second organic EL layer 9 in plan view. The partition 3 according to the present embodiment is formed in a lattice shape mainly in a region except for the first electrode 6 but also covers the periphery of the first electrode 6, As shown in Fig.

The first organic EL layer 7 corresponding to the hole injection layer is formed on the plurality of first electrodes 6 in the concave portion 5, respectively. The first organic EL layer 7 is formed so as to have a different material or thickness for each type (luminescent color) of the organic EL element 4, if necessary. Also, from the viewpoint of simplicity in the process of forming the first organic EL layer 7, all the first organic EL layers 7 can be formed with the same material and the same thickness.

A second organic EL layer 9 serving as a light emitting layer is formed on the first organic EL layer 7 in the concave portion 5. As described above, the light emitting layer is formed according to the type of the organic EL element. The red light emitting layer 9R is formed in the concave portion 5 in which the red organic EL device 4R is formed and the green light emitting layer 9G is formed in the concave portion 5 in which the green organic EL device 4G is formed And the blue light emitting layer 9B is formed in the concave portion 5 where the blue organic EL device 4B is formed.

The second electrode 10 is formed so as to cover the entire surface of the display region where the organic EL element 4 is formed. That is, the second electrode 10 is formed not only on the second organic EL layer 9 but also on the partition wall 3, and integrally with the plurality of organic EL elements 4, that is, the plurality of recesses 5 Respectively.

The surface of the second electrode 10 on the side of the substrate 2 is spaced away from the substrate 2 as it approaches the partition 3 from the central portion C of the organic EL element 4, . In other words, the surface (interface) constituted by the organic EL layer 9 in contact with the second electrode 10 and the partition 3 is in contact with the partition 3 from the center C in view of the plane of the organic EL element 4 It is preferable that the substrate 2 is gradually separated from the substrate 2. The surface of the organic EL layer 9 contacting the second electrode 10 and the surface of the partition wall 3 are configured as described above so that the distance between the organic EL layer 9 and the partition 3 It is possible to more effectively prevent disconnection in the vicinity.

In the above embodiment, the barrier rib 3 is formed in contact with the substrate 2 so as to cover the periphery of the first electrode 6, but as another embodiment, an insulating film may be formed between the barrier rib 3 and the substrate 2 . The insulating film may be formed in a lattice pattern in a plan view as in the case of the barrier rib, for example, and may be formed so as to cover the periphery of the first electrode 6. [ This insulating film is preferably formed of a material exhibiting lyophilicity more than the partition 3.

1, in the present embodiment, the contact region 31 is extended in the column direction Y at a position apart from one side (left direction in FIG. 1) of the row direction X of the display region 30 Respectively. The contact region means a region where a contact conductor for filling the contact hole and the contact hole is formed in this specification. In this embodiment, the contact regions 31 are formed extending in the column direction Y at positions apart from each other in the row direction X of the display region 30 (right direction in FIG. 1).

4, the end of the partition 3 on the side of the substrate 2 (the lower end in Fig. 4) is formed to be thicker than the thickness of the partition 3 (contact region 31) 2 formed between the side surface of the partition 3 defining the contact hole and the bottom surface of the partition 3 when the region including the contact region 31 is cut into a plane extending in the direction of the center of the contact hole 31 is an acute angle. That is, in the present embodiment, in the region where the contact hole is formed, the partition 3 having a net taper shape is formed. 2 is about 5 to 85, and preferably about 20 to 60 degrees.

In the contact region 31, a through hole is formed in the partition 3 corresponding to the contact hole, and a part of the electrode wiring 20 is exposed from the through hole. The through holes are formed to extend in the column direction Y in the present embodiment.

On the substrate 2, an electrode wiring 20 connected to an external power source is formed at a position in contact with the end portion (the lower end in FIG. 4) of the through hole at the substrate 2 side. Further, a conductor film formed integrally with the second electrode 10 is formed so as to be buried on the barrier rib 3 and in the contact hole. In this conductive film, a portion extending from the display region 31 to the contact hole over the partition wall 3 is referred to as a connection portion 23, and a portion where the contact hole is to be filled is referred to as a contact conductor 22.

The second electrode 10, the connecting portion 23 and the contact conductor 22 are integrally formed and the contact conductor 22 is connected to the electrode wiring 20 in this manner. As a result, the second electrode 10 is connected to the external power source by the connection portion 23, the contact conductor 22, and the electrode wiring 20.

Hereinafter, a method of manufacturing the display device will be described with reference to Figs. 5A to 8B.

Figs. 5A and 8B are schematic cross-sectional views of a display device during formation to illustrate a method of manufacturing the display device. Fig. 5A to 6C show the area (display area 30) shown in Fig. 3, and Figs. 7A to 8B show the area (contact area 31) corresponding to Fig.

(A step of preparing a substrate)

In this step, the first electrode 6 and the electrode wiring 20 are formed on the substrate 2 (see Figs. 5A and 7A). In this step, the substrate on which the first electrode 6 and the electrode wiring 20 are formed is obtained from the market to form the substrate 2 on which the first electrode 6 and the electrode wiring 20 are formed The substrate 2 on which the predetermined structure such as the wiring 20 is formed may be simply referred to as the substrate 2).

In the case of an active matrix type display device, a substrate on which circuits for driving a plurality of organic EL elements are formed in advance can be used as the substrate 2 of the present embodiment. For example, a substrate on which a TFT (Thin Film Transistor) and a capacitor are formed in advance may be used as the substrate 2. [

First, a plurality of first electrodes 6 are formed in a matrix on a substrate 2, and an electrode wiring 20 is formed in a predetermined region. The first electrode 6 is formed by forming a conductive thin film on one surface of the substrate 2 and patterning the conductive thin film into a matrix by a patterning process of a conductive thin film using a pattern formed by photolithography . Further, for example, a mask in which an opening is formed in a predetermined portion is disposed on the substrate 2, and a conductive material is selectively deposited on a predetermined portion of the substrate 2 through the mask to form the first electrode 6 Or may be formed as a predetermined pattern. The electrode wirings 20 are collectively formed with the first electrodes 6 in the same manner as the first electrodes 6, for example, in the same manner as the first electrodes 6. [ Materials of the first electrode 6 and the electrode wiring 20 will be described later (see Figs. 5A and 7A).

(Step of forming barrier ribs)

In this process, an ink (solution) containing a negative type photoresist material (photosensitive resin) is coated on a substrate to form a film for forming a barrier rib, and the exposure amount is changed in the region where the display region and the contact hole are formed, And the barrier ribs 3 are formed by patterning by exposure and development. The region in which the contact hole is formed means a region including the region where the contact conductor 22 is formed and the region including the periphery of the region where the contact conductor 22 is formed.

First, an ink containing a photosensitive resin is applied on the substrate 2 to form a film 8 for forming a barrier rib (see Figs. 5B and 7B).

Examples of the application method of the ink include a spin coating method and a slit coating method.

After the ink containing the photosensitive resin is applied onto the substrate 2, a prebaking step is usually carried out. The prebaking step is performed by heating the substrate at a temperature of, for example, 80 DEG C to 110 DEG C for 60 seconds to 180 seconds to remove the solvent, thereby forming a film 8 for forming a partition wall.

A photomask 21 (first photomask 21a) for shielding light 100 of a predetermined pattern is formed on the substrate 2 on which the barrier rib forming film 8 is formed as shown in Fig. And the partition wall forming film 8 is exposed through the photomask 21. The photosensitive resin includes positive and negative photosensitive resins, but a negative photosensitive resin is used in this step. When a negative-type photosensitive resin is used, light 100 is irradiated to a part of the partition wall forming film 8 where mainly the partition wall 3 is to be formed.

In the present embodiment, the barrier rib forming film 8 is exposed by changing the exposure amount in the region where the organic EL element is formed and the region where the contact hole is formed. By varying the exposure amount in this manner, the reverse tapered barrier ribs 3 can be formed in the display region 30, and the barrier ribs 3 in the tapered shape in the contact region 31 can be formed.

Specifically, in the case of using a proximity photolithography machine in which a division exposure can not be performed, two photomasks 21 are used to perform two exposures for each predetermined exposure region. As a result, the exposure amount can be made different in each exposure region.

When a stepper capable of divisional exposure is used, the amount of exposure can be made different by changing the exposure amount according to the exposure region using one photomask 21.

In the present embodiment, an example of using a proximity photolithography machine that can not perform divided exposure will be described in detail. In the exposure in this case, the exposure area is divided into the first exposure area and the second exposure area, and two kinds of photomasks 21 corresponding to the respective exposure areas are used to carry out exposure in two steps.

9 is a schematic plan view of a display device for explaining an exposure area. In the present embodiment, the first exposure area corresponds to the display area 30 and the peripheral part 32 surrounding the display area 30. And the second exposure area corresponds to an area excluding the display area 30. [ That is, the second exposure region includes the contact region 31. [ In this case, overlapping occurs in the peripheral edge portion 32 of the display region 30 in the first exposure region and the second exposure region. Therefore, the periphery 32 of the display area 30 is exposed twice.

The exposure of the first exposure area is performed first. The first photomask 21a is disposed on the substrate 2 and the light 100 is irradiated through the first photomask 21a to form a barrier rib in the first exposure region The light 100 is irradiated to the region of the solvent film 8, in which the partition wall 3 is to be mainly formed, with a first exposure dose. In Fig. 5C, the light 100 irradiated to the partition wall forming film 8 is schematically indicated by an outline arrow. Further, in this step, the contact region 31 is shielded by the first photomask 21a.

Then, the second exposure area is exposed. The second photomask 21b is disposed on the substrate 2 and the light 100 is irradiated through the photomask 21b as shown in Fig. Light is irradiated to the region of the film 8 where the partition 3 is to be formed, that is, the region excluding the contact region 31, at a second exposure amount. In Fig. 7C, the light 100 irradiated to the partition wall forming film 8 is schematically indicated by an outline arrow mark. In this step, the contact region 31 and the display region 30 are shielded by the second photomask 21b.

The amount of light obtained by integrating the first exposure amount and the second exposure amount is irradiated to a region where the first exposure region and the second exposure region overlap.

Generally, in the case of a negative-type photosensitive resin, the inclination angles? 1 and? 2 of the side faces of the partition tends to decrease as the exposure amount is increased. Therefore, the first exposure amount is set so that the exposure amount is smaller than the second exposure amount. The first exposure dose is set according to the inclination angle? 1, but is preferably 20 mJ / m 2 to 60 mJ / m 2, and preferably 20 mJ / m 2 to 40 mJ / m 2.

The second exposure dose is set according to the desired tilt angle? 2, but is preferably from 60 mJ / m 2 to 200 mJ / m 2, for example, from 80 mJ / m 2 to 100 mJ / m 2.

The inclination angles? 1 and? 2 can also be adjusted by adjusting the developing time. In general, in the case of a negative-type photosensitive resin, the inclination angles? 1 and? 2 tend to increase as the developing time is lengthened. Also, the inclination angles? 1 and? 2 can be adjusted by adjusting the distance between the photomask and the substrate 2. Generally, in the case of a negative type photosensitive resin, the inclination angles? 1 and? 2 tend to approach 90 degrees as the distance between the photomask and the substrate 2 is shortened.

The inclination angles? 1 and? 2 may also depend on the thickness of the partition forming film 8. Therefore, the thickness of the partition wall forming film 8 is preferably 0.5 탆 to 1 탆, more preferably 0.6 탆 to 0.7 탆.

Next, the development is performed. Whereby the barrier rib 3 is patterned (see Figs. 6A and 8A). After development, a post-baking step is carried out if necessary. The post bake process is performed by heating the substrate on which the partition walls 3 are patterned, for example, at a temperature of 200 캜 to 230 캜 for 15 minutes to 60 minutes to further harden the partition walls 3.

By forming the barrier ribs 3 as described above, the reverse tapered barrier ribs 3 are formed in the display region 30, and the barrier ribs 3 in the tapered shape in the contact regions 31 are formed.

As the composition (solution) of the photosensitive resin used for forming the barrier rib, a composition in which a binder resin, a crosslinking agent, a photoreaction initiator, a solvent, an ultraviolet absorber and other additives are mixed is generally used.

As the binder resin, a pre-polymerized polymer may be used. Examples of the binder resin include a non-polymerizable binder resin that does not have a self-polymerizing property, and a polymerizable binder resin into which a substituent having a polymerizable property is introduced. The binder resin has a weight average molecular weight of 5000 to 400000 as determined by gel permeation chromatography (GPC) using polystyrene as a standard.

Examples of the binder resin include a phenol resin, a novolac resin, a melamine resin, an acrylic resin, an epoxy resin, and a polyester resin. As the binder resin, monomers may be used alone or in combination of two or more. The content of the binder resin is usually 5% to 90% by mass with respect to the total solid content of the ink containing the photosensitive resin.

Examples of the crosslinking material include compounds having a polymerizable carbon-carbon unsaturated bond, which can be polymerized by an active radical, an acid, or the like generated from a photopolymerization initiator upon irradiation of light. The crosslinking material may be a monofunctional compound having one polymerizable carbon-carbon unsaturated bond in the molecule, or may be a bifunctional or trifunctional or multifunctional compound having two or more polymerizable carbon-carbon unsaturated bonds have. In the ink containing the photosensitive resin, the crosslinking agent is usually 0.1 part by mass or more and 70 parts by mass or less when the total amount of the binder resin and the crosslinking agent is 100 parts by mass. In the ink containing the photosensitive resin, the photoreaction initiator is usually 1 part by mass or more and 30 parts by mass or less when the total amount of the binder resin and the crosslinking agent is 100 parts by mass.

As the negative-type photosensitive resin composition, ZPN2464 manufactured by Nippon Zeon Co., Ltd. may be used specifically.

Further, a photosensitive resin composition containing a liquid repellent agent may be prepared by mixing a liquid repellent agent with the photosensitive resin composition. For the liquid repellent agent, for example, Daikin liquid developer Opto Ace (registered trademark) HP series can be used. The solid content ratio of the liquid repellent agent to the total solid content of the photosensitive resin composition excluding the liquid repellent agent (total solid content of the photosensitive resin composition excluding the liquid repellent agent / liquid repellent agent) x 100} is preferably 0.1% to 1.0% (mass).

The light 100 (irradiated light) irradiated to the photosensitive resin composition is absorbed by the ultraviolet absorber or the like, so that the light 100 becomes weaker from the surface side. As a result, the exposed and exposed photosensitive resin composition tends to be cured on the light-projecting side (surface side), and is harder to cure as it is spaced from the surface side. Therefore, when the exposure dose is small, the vicinity of the bottom surface (on the side of the substrate 2) where the irradiation light is difficult to reach hardly hardens and is exposed to the developer so that the shape of the side surface of the partition 3 becomes reverse tapered. On the other hand, when light is irradiated at an exposure amount sufficient to cure the photosensitive resin composition in the thickness direction, it may be in a net taper shape.

Examples of the developer used in the development include an aqueous solution of potassium chloride, an aqueous solution of tetramethylammonium hydroxide (TMAH), and the like.

The shape and arrangement of the barrier ribs 3 are appropriately set in accordance with the specification of the display device such as the number of pixels and the resolution, ease of manufacture, and the like. The width of the partition wall 3 in the display area 30 in the row direction X or the column direction Y is, for example, about 5 탆 to 50 탆 and the height (thickness) of the partition 3 is 0.3 탆 to 5 탆 And the interval between the adjacent partition walls 3 in the row direction X or the column direction Y, that is, the width of the concave portion 5 in the row direction X or the column direction Y is about 10 to 200 mu m. In addition, the widths of the first electrodes 6 in the row direction X or the column direction Y are each about 10 mu m to 200 mu m.

The width of the contact hole in the row direction X of the partition 3 in the contact region 31 is about 3 to 5000 mu m.

(Step of forming organic EL layer)

As shown in Fig. 6B, an organic EL layer is formed in this step. In the present embodiment, at least one organic EL layer of one or more organic EL layers is formed by a coating method. In the present embodiment, the first organic EL layer 7 and the second organic EL layer 9 are formed by a coating method.

Ink containing a material serving as the first organic EL layer 7 is first supplied (applied) to a region (concave portion 5) surrounded by the partition 3. The ink is appropriately supplied by an optimum method in consideration of the shape of the partition wall 3, the simplicity of the forming process, and the film forming property. The ink is supplied by, for example, an inkjet printing method, a nozzle coating method, an iron plate printing method, intaglio printing method or the like.

Next, the first organic EL layer 7 is formed by solidifying the supplied ink. The solidification of the ink can be carried out by, for example, natural drying, heat drying, or vacuum drying. When the ink contains a material capable of polymerizing by the application of energy, the material constituting the organic EL layer may be polymerized by heating the thin film or by irradiating light to the thin film after supplying the ink. By polymerizing the material constituting the organic EL layer as described above, the organic EL layer can be hardened with respect to the ink used when the organic EL layer is further formed on the organic EL layer.

Next, a second organic EL layer 9 functioning as a light emitting layer is formed. The second organic EL layer 9 can be formed in the same manner as the first organic EL layer 7. That is, three types of inks (a red ink for forming the red light emitting layer 9R and a green light emitting layer 9G) are formed, which include a material consisting of a red luminescent layer 9R, a green luminescent layer 9G and a blue luminescent layer 9B Green ink for forming the blue light emitting layer 9B and blue ink for forming the blue light emitting layer 9B are each supplied to the region surrounded by the partition 3 and solidified to supply the red light emitting layer 9R, Can be further formed.

When the organic EL layer is formed by the coating method as described above, since the inversely tapered barrier ribs are formed, the ink supplied to the region (concave portion 5) surrounded by the barrier ribs 3 is guided by the capillary phenomenon, So that the tip to which the electrode 6 and the partition 3 are connected is sucked into the thin portion 7a. The solvent of the ink is evaporated while maintaining this state, so that the organic EL layer is also formed at the portion where the first electrode 6 and the partition 3 are connected. Thereby, the organic EL layer 7 having a uniform thickness can be obtained.

The portion 7a having a narrow shape to which the first electrode 6 and the partition 3 are connected is filled with the material constituting the organic EL layer 7, As the surface (the surface of the organic EL layer 7) constituted by the EL layer 9 and the partition 3 approaches the partition 3 from the central portion C of the organic EL element 4 in plan view, (2).

(A step of forming a second electrode or the like)

Next, a conductive thin film is formed in the entire region (at least the display region 30 and the contact region 31, and the region between the display region 30 and the contact region 31) excluding the predetermined region of the substrate 2 do. Thus, the second electrode 10, the connecting portion 23, and the contact conductor 22 are formed.

Even if the thicknesses of the connection portions 23 and the contact conductors 22 are thin, the contact portions 31 are formed at the ends of the partition walls 3, Can be prevented.

In the display region 30, the barrier ribs 3 are formed in an inverted tapered shape. However, the end portions of the regions surrounded by the barrier ribs 3 on the substrate 2 side It is possible to prevent the second electrode 10 from being disconnected from the end of the barrier rib 3 even when the thickness of the second electrode 10 is thinner because it is filled with the material of the organic EL layers 7 and 9 .

As described above, the barrier ribs 3 are formed in a net taper shape in the contact region 31 and the barrier ribs 3 are formed in the reverse tapered shape in the display region 30 so that the second electrodes 10, And the contact conductors 22 can be made thinner, and the time required for forming the contact conductors 22 can be shortened as compared with the prior art.

Thicknesses of the second electrode 10, the connecting portion 23 and the contact conductor 22 are set in consideration of the electric resistance and the film forming time which are required, but are preferably 10 nm to 1 탆, preferably 50 nm to 500 nm , And more preferably 100 nm to 200 nm.

The surface of the second electrode 10 on the substrate 2 side is spaced apart from the substrate 2 as it approaches the partition wall 3 from the central portion C as viewed from the plane of the organic EL element 4, . In other words, the surface (the surface of the organic EL layer 9) constituted by the organic EL layer 9 and the partition wall 3 in contact with the second electrode 10 faces the center of the organic EL element 4 C to the barrier rib 3, as shown in Fig. The surface of the organic EL layer 9 contacting the second electrode 10 and the surface of the barrier rib 3 constitute the second electrode 10, It is possible to prevent disconnection in the boundary region.

≪ Configuration of Organic EL Device >

Hereinafter, the structure of the organic EL device of the present embodiment will be described in more detail. The organic EL element has at least one luminescent layer as the organic EL layer. However, as described above, as the organic EL layer, a hole injecting layer, a hole transporting layer, an electron blocking layer, a hole blocking layer, an electron transporting layer, And the like.

An example of the layer configuration that can be taken by the organic EL device of the present embodiment is shown below.

a) anode / light emitting layer / cathode

b) anode / hole injection layer / light emitting layer / cathode

c) anode / hole injection layer / light emitting layer / electron injection layer / cathode

d) anode / hole injecting layer / light emitting layer / electron transporting layer / electron injecting layer / cathode

e) anode / hole injecting layer / hole transporting layer / light emitting layer / cathode

f) anode / hole injecting layer / hole transporting layer / light emitting layer / electron injecting layer / cathode

g) anode / hole injecting layer / hole transporting layer / light emitting layer / electron transporting layer / electron injecting layer / cathode

h) anode / light emitting layer / electron injection layer / cathode

i) anode / light emitting layer / electron transporting layer / electron injecting layer / cathode

Here, the symbol " / " indicates that the respective layers sandwiching the symbol " / "

In the above-described embodiment, the description has been given of the organic EL element in which the first electrode 6 functioning as the anode is disposed in the vicinity of the substrate 2 with respect to the second electrode 10. However, The first electrode 6 may be disposed closer to the substrate 2 with respect to the second electrode 10 than the organic EL device. Further, the organic EL element may be formed in such a manner that the cathode is formed on the substrate 2 in order from the anode to the top layer in the layer structure of the above a) to i) And the anode is formed on the uppermost layer. Hereinafter, each constituent element related to the above-mentioned layer structure will be described.

<Substrate>

As the substrate 2, a substrate which does not chemically change in the process of manufacturing the organic EL device is suitably used. As the substrate 2, for example, a glass substrate, a plastic substrate, a polymer film substrate and a silicon substrate, and a substrate obtained by laminating them are used.

<Anode>

In the case of an organic EL element in which the light emitted from the light emitting layer is transmitted through the anode to the outside, an electrode exhibiting light transmittance is used for the anode. As the electrode exhibiting light transmittance, a thin film of a metal oxide, a metal sulfide, a metal, or the like can be used, and a material having high electric conductivity and high light transmittance is suitably used. Specifically, it includes indium oxide, zinc oxide, tin oxide, indium tin oxide (ITO), indium zinc oxide (IZO), gold, platinum, silver and copper A thin film containing ITO, IZO or tin oxide is suitably used. Examples of the method for producing the anode include a vacuum deposition method, a sputtering method, an ion plating method, and a plating method. As the anode, a transparent conductive film containing an organic material such as polyaniline or a derivative thereof, a polythiophene or a derivative thereof may be used.

<Cathode>

As the material of the cathode, a material having a small work function, easy injection of electrons into the light emitting layer, and high electric conductivity is preferable. Further, in the organic EL device having a structure for extracting light from the anode side, a material having high reflectivity to visible light is preferable as a material for the cathode, because light emitted from the light emitting layer is reflected from the cathode to the anode side. As the cathode, for example, an alkali metal, an alkaline earth metal, a transition metal, and a Group 13 metal of the periodic table can be used. Examples of the material of the negative electrode include lithium, sodium, potassium, rubidium, cesium, beryllium, magnesium, calcium, strontium, barium, aluminum, scandium, vanadium, zinc, yttrium, indium, cerium, samarium, europium, terbium, At least one of the metals and at least one of gold, silver, platinum, copper, manganese, titanium, cobalt, nickel, tungsten and tin or graphite or intergranular compound Is used. Examples of the alloys include magnesium-silver alloys, magnesium-indium alloys, magnesium-aluminum alloys, indium-silver alloys, lithium-aluminum alloys, lithium-magnesium alloys, lithium-indium alloys and calcium-aluminum alloys. As the cathode, a transparent conductive electrode containing a conductive metal oxide, a conductive organic material, or the like can be used. Specifically, examples of the conductive metal oxide include indium oxide, zinc oxide, tin oxide, ITO and IZO, and examples of the conductive organic material include polyaniline or derivatives thereof, polythiophenes or derivatives thereof, and the like. The negative electrode may be formed as a laminate of two or more layers. In some cases, the electron injection layer doubles as a cathode.

Examples of the method for producing the negative electrode include a vacuum evaporation method and an ion plating method.

The thickness of the anode or the cathode can be appropriately set in consideration of required characteristics, simplicity of the manufacturing process, and the like. The thickness of the anode or the cathode is, for example, 10 nm to 10 탆, preferably 20 nm to 1 탆, and more preferably 50 nm to 500 nm. The thickness of the electrode formed as the second electrode in the anode and the cathode is set in consideration of the required electrical resistance and fabrication time as described above but is preferably 10 nm to 1 탆 and preferably 50 nm to 500 nm , And more preferably 100 nm to 200 nm.

The electrode wirings 20, the connecting portions 23 and the contact conductors 22 can be manufactured by using materials exemplified as materials for the negative electrode and the positive electrode. It is preferable that the connection portion 23 and the contact conductor 22 are formed by the same process using the same material as the second electrode 10. It is not necessary to use the same material as the first electrode 6 or the second electrode 10 in the electrode wiring 20 but the electrical resistance of the electrode wiring 20 should be smaller than that of the first electrode 6 or the second electrode 10 And it is preferable that the contact resistance with the contact conductor 22 is reduced.

<Hole injection layer>

Examples of the hole injection material constituting the hole injection layer include oxides such as vanadium oxide, molybdenum oxide, ruthenium oxide and aluminum oxide, phenylamine compounds, starburst amine compounds, phthalocyanine compounds, amorphous carbon, polyaniline and polythiophene And derivatives thereof.

As a method for producing the hole injection layer, for example, a coating process using a solution containing a hole injection material can be mentioned. As a method of manufacturing the hole injection layer, for example, a solution containing a hole injection material may be applied by a predetermined coating method and solidified to form a hole injection layer.

The thickness of the hole injection layer is suitably set in consideration of required characteristics and simplicity of the process. The thickness of the hole injection layer is, for example, 1 nm to 1 占 퐉, preferably 2 nm to 500 nm, and more preferably 5 nm to 200 nm.

&Lt; Hole transport layer &

Examples of the hole transporting material constituting the hole transporting layer include polyvinylcarbazole or derivatives thereof, polysilane or derivatives thereof, polysiloxane derivatives having an aromatic amine structure in the side chain or main chain, pyrazoline derivatives, arylamine derivatives, stilbene derivatives Polypyrroles or derivatives thereof, poly (p-phenylenevinylene) or derivatives thereof, poly (2,5-dihydroxyphenylenevinylene) or derivatives thereof, polyaniline or derivatives thereof, polyaniline or derivatives thereof, Thienylene vinylene) or a derivative thereof.

The thickness of the hole transporting layer is set in consideration of required characteristics and simplicity of the manufacturing process. The thickness of the hole transporting layer is, for example, from 1 nm to 1 占 퐉, preferably from 2 nm to 500 nm, and more preferably from 5 nm to 200 nm.

<Light Emitting Layer>

The light-emitting layer usually includes an organic material (light-emitting material) that emits fluorescence and / or phosphorescence, or a corresponding organic material and a dopant material that assists the organic material. The dopant material is added, for example, in order to improve the luminous efficiency or change the emission wavelength. The organic material constituting the light emitting layer may be a low molecular compound or a high molecular compound, and when forming the light emitting layer by a coating method, the material of the light emitting layer preferably contains a polymer compound. The number average molecular weight of the polymer compound constituting the light emitting layer in terms of polystyrene is, for example, about 10 ³ to 10 ⁸ . Examples of the light emitting material constituting the light emitting layer include the following dye materials, metal complex materials, polymer materials, and dopant materials.

(Dye material)

Examples of the dye material include a cyclopentamine derivative, a tetraphenylbutadiene derivative, a triphenylamine derivative, an oxadiazole derivative, a pyrazoloquinoline derivative, a distyrylbenzene derivative, a distyrylarylene derivative, a pyrrole derivative, a thiophene ring structure A compound containing a pyridine ring structure, a perinone derivative, a perylene derivative, an oligothiophene derivative, an oxadiazole dimer, a pyrazoline dimer, a quinacridone derivative, and a coumarin derivative.

(Metal complex material)

Examples of the metal complex material include a rare earth metal such as Tb, Eu, and Dy or a metal such as Al, Zn, Be, Ir, and Pt in a central metal, and oxadiazole, , A quinoline structure, and the like. Examples of the metal complex include metal complexes having luminescence from triplet excited states such as iridium complexes and platinum complexes, aluminum quinolinol complexes, benzoquinolinol beryllium complexes, Benzooxazolyl zinc complex, benzothiazole zinc complex, azomethyl zinc complex, porphyrin zinc complex, phenanthroline europium complex, and the like.

(Polymer material)

Examples of the polymer material include a polyparaphenylene vinylene derivative, a polythiophene derivative, a polyparaphenylene derivative, a polysilane derivative, a polyacetylene derivative, a polyfluorene derivative, a polyvinylcarbazole derivative, a dye material or a metal complex material And polymerized.

The thickness of the light emitting layer is usually about 2 nm to 200 nm.

<Electron transport layer>

As the electron transporting material constituting the electron transporting layer, known materials can be used. Examples of the electron transporting material constituting the electron transporting layer include oxadiazole derivatives, anthraquinodimethane or derivatives thereof, benzoquinone or derivatives thereof, naphthoquinone or derivatives thereof, anthraquinone or derivatives thereof, tetracyanoanthracene A metal complex of 8-hydroxyquinoline or a derivative thereof, a polyquinoline or a derivative thereof, a polyquinoxaline or a derivative thereof, a polyquinoline derivative or a derivative thereof, a fluorenone derivative, a diphenyldicyanoethylene or a derivative thereof, a diphenoquinone derivative or a metal complex of 8- Polyfluorene or derivatives thereof, and the like.

The thickness of the electron transporting layer is suitably set in consideration of required characteristics, simplicity of the manufacturing process, and the like. The thickness of the electron transporting layer is, for example, from 1 nm to 1 占 퐉, preferably from 2 nm to 500 nm, and more preferably from 5 nm to 200 nm.

<Electron injection layer>

As the material for constituting the electron injection layer, an optimum material is appropriately selected depending on the kind of the light emitting layer, and an alloy containing at least one of alkali metals, alkaline earth metals, alkali metals and alkaline earth metals, an oxide of an alkali metal or an alkaline earth metal, Halides, carbonates, and mixtures of these materials. Examples of the alkali metal and the alkali metal oxides, halides and carbonates include lithium, sodium, potassium, rubidium, cesium, lithium oxide, lithium fluoride, sodium oxide, sodium fluoride, potassium oxide, potassium fluoride, rubidium oxide, Cesium, cesium fluoride, lithium carbonate and the like. Examples of the oxides, halides and carbonates of alkaline earth metals and alkaline earth metals include magnesium, calcium, barium, strontium, magnesium oxide, magnesium fluoride, calcium oxide, calcium fluoride, barium oxide, barium fluoride, strontium oxide, strontium fluoride, Magnesium, and the like. The electron injection layer may be composed of a laminate of two or more layers, for example, a laminate of a LiF layer and a Ca layer.

The thickness of the electron injection layer is preferably about 1 nm to 1 mu m.

Each of the organic EL layers described above can be formed by a coating method such as a nozzle coating method, an inkjet printing method, an iron plate printing method, an intaglio printing method, a vacuum evaporation method, a sputtering method, a CVD method or the like. When a plurality of organic EL layers are provided, at least one organic EL layer is formed by a coating method.

In the coating method, an ink containing an organic EL material corresponding to each organic EL layer is applied, and the applied ink is solidified to further form an organic EL layer. As the solvent for the ink used in the coating method, for example, there can be used chlorine solvents such as chloroform, methylene chloride and dichloroethane, ether solvents such as tetrahydrofuran, aromatic hydrocarbon solvents such as toluene and xylene, ketones such as acetone and methyl ethyl ketone Solvents, ester solvents such as ethyl acetate, butyl acetate, and ethyl cellosolve acetate, and water.

Example

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the following Examples.

(Example 1)

First, a TFT substrate on which a first electrode (anode) including an ITO thin film and an electrode wiring were patterned in advance was prepared (Figs. 5A and 7A).

Next, a liquid developer (Daikin liquid developer Opto Ace (registered trademark) HP series) was mixed with a solution of a negative type photosensitive resin (ZPN2464 manufactured by Nippon Zeon Co., Ltd.), and a solution of the photosensitive resin containing the liquid repellent agent . The concentration of the liquid repellent agent in terms of solid content relative to the photosensitive resin was 0.2 wt%. Next, a solution of the photosensitive resin containing the liquid repellent agent was coated on the surface of the prepared TFT substrate by a spin coater, and the film was pre-baked by heating on a hot plate at 110 DEG C for 90 seconds to evaporate the solvent, (See Figs. 5B and 7B).

Next, a photomask A (first photomask 21a) and a photomask B (second photomask 21b) for the proximity photoresist were prepared. The first exposure region (the display region 30 and the peripheral portion 32 of the display region 30) was exposed at an exposure dose of 40 mJ / cm 2 using the photomask A (see Figs. 5C and 9). Subsequently, the second exposure area (area excluding the display area 30) was exposed at 80 mJ / cm 2 using the photomask B (see FIGS. 7C and 9). More specifically, in the second exposure region, a region except for the contact region where the contact hole is formed was exposed. Thereafter, the film was exposed at 110 DEG C for 60 seconds and baked (PEB). Subsequently, development was carried out by using a developing solution (SD-1 (TMAH 2.38% by weight) manufactured by TOKUYAMA Corporation) for 50 seconds to remove the photosensitive resin of the unexposed portion. Further, the post-baking treatment was conducted at 230 DEG C for 30 minutes to cure the photosensitive resin. Thereby, inversely tapered barrier ribs and recesses defined by the barrier ribs are formed in the display region, and in the outside of the display region (including the contact region where the contact holes are formed), net tapered barrier ribs and concave portions defined therein are formed (See Figs. 6A and 8A).

The thickness of the partition wall in the thickness direction of the TFT substrate was 0.7 mu m. As described above, there are cases in which the inclination angles? 1 and? 2 of the side faces of the barrier ribs depend on the thickness of the barrier ribs. When the thickness of the barrier ribs is 0.7 占 퐉 as in the present embodiment, when the exposure amount is 40 mJ / And when the exposure amount is 80 mJ / cm 2 or more, a net tapered barrier rib can be formed. In the display area 30, the angle? 1 formed by the side surface of the partition 3 and the surface of the substrate (the bottom surface of the partition 3) was 150 占.

In the region where the contact hole is formed, the angle? 2 formed by the side surface of the partition 3 and the bottom surface of the partition 3 was 25 占.

The contact angle of the anisole with the top surface (surface) of the bulkhead was 50 °. In addition, the contact angle of pure water with the surface of the first electrode (ITO thin film) was 25 °.

Next, a hole injection layer was formed as a first organic EL layer. First, the exposed surface was rinsed with ozone water (concentration: 2 ppm, treatment time: 5 minutes) using an ozonated water production apparatus (FA-1000ZW12-5C manufactured by Loki Techno Co., Ltd.). By this cleaning, the contact angle of the surface of the first electrode (ITO thin film) and pure water was reduced to 5 DEG or less, and sufficient wettability could be imparted to the surface of the first electrode (ITO thin film).

Next, an ink (1.5 wt% of poly (ethylene dioxythiophene) (PEDOT) / polystyrene sulfonic acid (PSS) water dispersion (manufactured by Bayer Co., Ltd.) AI4083) was applied to each recess.

Since the ink is repelled by the top face of the partition wall having a high contact angle, it is possible to prevent the ink from overflowing to the adjacent region on the top face, and the ink can be accommodated in the predetermined recess. On the other hand, the ink accommodated in the predetermined concave portion is filled so as to be sucked into the thin-shaped portion where the first electrode and the partition wall are connected by the capillary phenomenon and uniformly spread in the concave portion. Subsequently, baking was performed at 200 占 폚 to form a hole injection layer having a substantially uniform thickness (50 nm) (see Fig. 6B). Here, the thickness means the thickness of the central portion of the concave portion in plan view.

Next, three kinds of light emitting layers were formed. First, an ink (red ink) was prepared by mixing a polymer light emitting material that emits red light into an organic solvent so that its concentration becomes 0.8 wt%. Similarly, an ink (green ink) was prepared by mixing a polymer light emitting material that emits green light with an organic solvent so that the concentration thereof became 0.8 wt%. Then, a polymer light emitting material which emits blue light was mixed with an organic solvent so that the concentration thereof became 0.8% by weight to prepare an ink (blue ink). The red ink, the green ink, and the blue ink were applied to predetermined concave portions by using an ink jet apparatus (Little Lex 142P, manufactured by ULVAC). Since the ink is repelled by the top face of the partition wall having a high contact angle, the ink does not overflow into the adjacent region (recessed portion) on the top face and is accommodated in the recessed portion. On the other hand, the ink contained in the concave portion was filled so as to be sucked into a portion having a narrow shape where the first electrode and the partition wall were connected by the capillary phenomenon, and spread uniformly in the concave portion. Then, a light emitting layer having a uniform thickness (60 nm) was formed by baking at 130 캜 (see Fig. 6-2). Further, a light emitting layer may be formed using, for example, a polymer light emitting material manufactured by Surimation.

Next, a layer containing 2 nm of NaF, a layer of 2 nm of Mg, and a layer of Al of 200 nm thickness are laminated in this order by a vacuum deposition method to form a second electrode (Cathode), a connecting portion, and a contact conductor. Thereafter, the sealing substrate was bonded to the second electrode side, and the formed organic EL device was sealed to fabricate a display device.

(Substrate side) surrounding the pixel (organic EL element) after the light emitting layer is formed is buried with the material constituting the organic EL layer and is formed into a flat shape without a step from the surface of the partition wall to the surface of the organic EL layer Could. As a result, a second electrode of Al having a thickness of 200 nm, which is formed over all of the organic EL elements, was formed. As described above, even if the periphery of the pixel is surrounded by the reverse tapered barrier rib, the thinner cathode is not broken. Further, in the contact region, the partition walls themselves are formed in a net taper shape, so that they are not disconnected even if the connection portions and the contact conductors have a small thickness. It was confirmed that the manufactured display device emits normally in a display area where a plurality of organic EL elements are formed.

1 display device
2 substrate
3 barrier
3a End portion of the partition wall 3 on the substrate 2 side
3b The end portion of the partition wall 3 opposite to the substrate 2 side
4 organic EL device
5 concave portion
6 First electrode
7, 54 First organic EL layer (hole injection layer)
7a A region with a thin end
8 Films for forming barrier ribs
9, 55 Second organic EL layer (light emitting layer)
10 Second electrode
20 electrode wiring
21 Photomasks
21a First photo mask
21b Second photomask
22 contact conductors
23 connection
30 Display area
31 contact area
32 circumference
51 barrier
52 Organic EL device
53 first electrode
56 Second electrode
57 tip
58 substrate
61 connection
62 Contact conductors
63 electrode wiring
100 light

Claims (4)

A substrate;
A plurality of organic electroluminescent elements formed in a display region on the substrate,
And a barrier rib defining a contact hole formed outside the display region, wherein the barrier rib is formed in a region where the plurality of organic electroluminescent elements are formed,
Wherein the plurality of organic electroluminescent elements comprise a first electrode, a second electrode formed to be spaced from the substrate with respect to the first electrode, and a second electrode formed between the first electrode and the second electrode, An organic electroluminescent layer,
The second electrode has a connection portion extending from the display region to the contact hole over the partition wall,
Wherein an end of the barrier rib on the substrate side has an obtuse angle formed by the side surface of the barrier rib and the bottom surface of the barrier rib in the display region and the side surface of the barrier rib and the bottom surface of the barrier rib in the region where the contact hole is formed And the angle formed is an acute angle. The display device according to claim 1, wherein an end portion of the partition wall opposite to the substrate side has an acute angle formed by a side face of the partition wall and a bottom face of the partition wall in the display region. 3. The display device according to claim 1 or 2, wherein a surface of the second electrode on the substrate side is spaced apart from the substrate as it approaches the partition from the central portion of the organic electroluminescent device. A manufacturing method of a display device according to any one of claims 1 to 3,
A step of applying a solution of a negative-type photosensitive resin on a substrate to form a coating film for forming a barrier rib,
Forming the barrier ribs by exposing and developing the barrier rib formation coating film with different exposure amounts in the regions where the display region and the contact holes are formed
And a step of forming the display device.

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