TW201507145A - Display device - Google Patents

Abstract

The present invention provides a display device (1) with an inverse tapered spacing wall capable of thinning the thickness of a second electrode. The display device (1) comprises a substrate (2), a plurality of organo electroluminescence elements provided on a display area (30) over the substrate and a spacing wall defining the area provided with the organo electroluminescence element and contact holes provided outside the display area. The plurality of organo electroluminescence elements each comprises, a first electrode, a second electrode provided far away from the substrate than the first electrode, and one or more layers of organo electroluminescence layers provided between the first electrode and the second electrode. The second electrode includes a connection part extending over the spacing wall from the display area to the contact holes. With regard to the edge of the spacing wall on substrate side, in the display area, the angle formed by the side face and the bottom face of the spacing wall is an obtuse angle, in the area formed with the contact holes, the angle formed by the side face and the bottom face of the spacing wall is an acute angle.

Description

Display device

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

One of the known display devices is a display device using an organic electroluminescence element (hereinafter referred to as an organic EL element) in a pixel light source. For example, a color display device is provided with three types of organic EL elements as pixel light sources. In other words, (1) a red organic EL element that emits red light, (2) a green organic EL element that emits green light, and (3) a blue organic EL element that emits blue light is provided on the substrate.

A partition wall defining a region where the organic EL element is provided is usually provided on the substrate. Such a partition wall is provided with, for example, a lattice-shaped partition wall. The three types of organic EL elements are arranged in a matrix in a region surrounded by the partition walls.

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

As shown in Fig. 10, the partition wall can be roughly divided into a so-called tapered shape partition wall and a reverse tapered shape partition wall. The partition wall having a tapered shape refers to a side surface of the partition wall defining the concave portion when the region including the concave portion defined by the partition wall is cut by a plane extending in the thickness direction of the partition wall. The angle formed by the bottom surface of the partition wall is formed in such a manner as to form an acute angle. The partition wall of the inverted tapered shape refers to an angle formed by the side surface of the partition wall defining the concave portion and the bottom surface of the partition wall when the region including the concave portion defined by the partition wall is cut in a plane extending in the thickness direction of the partition wall. Formed in such a way as to form an obtuse angle. In Fig. 10, the inverted tapered shape, that is, the partition wall 51 formed by the side surface of the partition wall and the bottom surface of the partition wall at an obtuse angle is shown.

Each of the organic EL elements 52 is composed of a first electrode 53, a layer or a plurality of organic EL layers (first organic EL layer 54, second organic EL layer 55) and a second electrode in a region surrounded by the partition walls 51. 56 is formed by sequential lamination.

The first organic EL layer 54 and the second organic EL layer 55 are formed, for example, by a coating method. Specifically, the ink containing the materials of the first organic EL layer 54 and the second organic EL layer 55 is applied to a region surrounded by the partition walls 51 and cured.

Further, the ink applied to the region surrounded by the partition wall 51 may be plucked by the surface of the first electrode 53 or the surface of the partition wall 51. When the ink is plucked by the surface of the first electrode 53 or the surface of the partition wall 51, the first organic EL layer 54 may be defective in the second organic EL layer 55.

When the partition wall 51 of the inverted tapered shape is used, the occurrence of such a problem can be suppressed. When the partition wall 51 having a reverse tapered shape is used, the interval in the vicinity of the portion where the side surface of the partition wall 51 and the surface of the first electrode 53 are in contact with each other is narrowed so as to be close to the tip end portion 57 of the contact portion. Therefore, a capillary phenomenon occurs at the tip end portion 57. Produced by this capillary phenomenon The green ink is diffused to the entire area surrounded by the partition wall 51, and the occurrence of defects of the first organic EL layer 54 and the second organic EL layer 55 can be prevented (for example, see Patent Document 1).

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication 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, the first electrode 53 and the second electrode 56 must be electrically connected to an external power source.

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

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

11 and 12 are schematic cross-sectional views showing contact areas.

As shown in Fig. 11, specifically, the second electrode 56 is transmitted through the connection portion 61 of the contact region extending from the display region in which the plurality of organic EL elements are provided to the display region beyond the display region, and is provided in contact with The contact conductor 62 in the region and the electrode wiring 63 provided on the substrate are connected to an external power source.

The partition wall 51 not only defines a region in which the organic EL element is provided, but also defines a contact hole provided outside the display region. Formed. Further, the partition wall 51 defining the region in which the organic EL element is provided and the partition wall 51 defining the contact hole are formed, for example, by the photolithography step in the same step. Further, the connection portion 61 extending over the partition wall 51 and the contact conductor 62 provided in the contact hole are formed together when the second electrode 56 is formed.

When the connecting portion 61 and the contact conductor 62 are formed in the same step as the second electrode 56, the connecting portion 61 and the contact conductor 62 have the same thickness as the second electrode 56.

Therefore, when the second electrode 56 (connecting portion 61) having a thinner thickness is formed by a vapor deposition method or the like, as shown in Fig. 12, there is a possibility that a disconnection occurs in the contact region.

In order to prevent disconnection of the contact area, the thickness of the second electrode 56 (that is, the thickness of the connecting portion 61) must be thicker. When the thickness of the second electrode 56 is made thicker as described above, the time required to form the electrode becomes longer, and the damage to the light-emitting layer or the like is increased when the electrode is formed. In addition, even if the second electrode 56 having a small thickness is formed in the display region, the first organic EL layer 54 and the second organic EL layer 55 are formed in the region surrounded by the partition wall 51, so that occurrence of disconnection can be avoided.

Therefore, an object of the present invention is to provide a display device which can further reduce the thickness of the second electrode (upper electrode) 56 in a display device including the partition wall 51 having a reverse tapered shape.

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

[1] A display device comprising: a substrate, a plurality of organic electroluminescent elements disposed on the display region on the substrate, and a partition defining a region in which the plurality of organic electroluminescent elements are disposed and a contact hole disposed outside the display region, wherein the plurality of The organic electroluminescent device has a first electrode, a second electrode that is disposed away from the substrate from the first electrode, and a layer or a plurality of layers that are provided between the first electrode and the second electrode. In the electromechanical excitation layer, the second electrode has a connection portion extending from the display region to the contact hole on the partition wall, and an end portion of the partition wall on the substrate side is a side surface of the partition wall in the display region The angle formed by the bottom surface of the partition wall is an obtuse angle, and the angle formed by the side surface of the partition wall and the bottom surface of the partition wall is an acute angle in a region where the contact hole is formed.

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

[3] The display device according to [1], wherein the surface of the second electrode on the substrate side is from the central portion of the organic electroluminescent device to the partition wall. The aforementioned substrate is away.

[4] A method of manufacturing a display device according to any one of [1] to [3], comprising: coating a negative photosensitive resin solution on a substrate to form a partition wall; The steps of coating the film, and The step of forming the partition walls by exposing and developing the coating film for forming the partition walls by differentiating the exposure amount between the display region and the region in which the contact holes are provided.

According to the invention, the thickness of the second electrode (upper electrode) can be reduced in a display device having a partition wall having a reverse tapered shape.

1‧‧‧ display device

2, 58‧‧‧ substrate

3, 51‧‧‧ partition wall

3a‧‧‧End of the base 2 side of the partition 3

3b‧‧‧ the end opposite to the side of the substrate 2 of the partition 3

4, 52‧‧‧ Organic EL components

5‧‧‧ recess

6, 53‧‧‧ first electrode

7, 54‧‧‧1st organic EL layer (hole injection layer)

7a‧‧‧ pointed tip

8‧‧‧membrane for partition wall formation

9, 55‧‧‧2nd organic EL layer (light-emitting layer)

10, 56‧‧‧ second electrode

20‧‧‧Electrode wiring

21‧‧‧Photomask

21a‧‧‧1st mask

21b‧‧‧2nd mask

22, 62‧‧‧Contact conductor

23, 61‧‧‧ Connections

30‧‧‧Display area

31‧‧‧Contact area

32‧‧‧The Peripheral Department

57‧‧‧ apex

63‧‧‧Electrode wiring

100‧‧‧Light

Figure 1 is a schematic plan view of a display device.

Figure 2 is a plan view schematically showing a part of the display area.

Fig. 3 is a cross-sectional view schematically showing a region in which one organic EL element is provided in a display region.

Fig. 4 is a cross-sectional view showing a state in which a contact region is cut in a plane perpendicular to the column direction Y.

Fig. 5A is a schematic cross-sectional view showing the display device in the middle of formation shown in the method of manufacturing the display device.

Fig. 5B is a schematic cross-sectional view showing the display device in the middle of formation shown in the method of manufacturing the display device.

Fig. 5C is a schematic cross-sectional view showing the display device in the middle of formation shown in the method of manufacturing the display device.

Fig. 6A is a schematic cross-sectional view showing a display device in the middle of formation shown in the method of manufacturing the display device.

Fig. 6B is a schematic cross-sectional view showing the display device in the middle of formation shown in the method of manufacturing the display device.

Fig. 6C is a schematic cross-sectional view showing the display device in the middle of formation shown in the method of manufacturing the display device.

Fig. 7A is a schematic cross-sectional view showing a display device in the middle of formation shown in the method of manufacturing the display device.

Fig. 7B is a schematic cross-sectional view showing the display device in the middle of formation shown in the method of manufacturing the display device.

Fig. 7C is a schematic cross-sectional view showing the display device in the middle of formation shown in the method of manufacturing the display device.

Fig. 8A is a schematic cross-sectional view showing the display device in the middle of formation shown in the method of manufacturing the display device.

Fig. 8B is a schematic cross-sectional view showing the display device in the middle of formation shown in the method of manufacturing the display device.

Figure 9 is a schematic plan view of the display device.

Figure 10 is a schematic cross-sectional view showing a pixel.

Figure 11 is a schematic cross-sectional view showing the contact area.

Figure 12 is a schematic cross-sectional view showing the contact area.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, each figure shows the shape, size, and arrangement of a component in the outline of an understandable invention. The present invention is not limited to the following description, and each constituent element can be appropriately changed without departing from the scope of the invention. In the drawings used in the following description, the same components are denoted by the same reference numerals, and the description of the repetition is omitted.

A display device according to the present invention includes a substrate, a plurality of organic EL elements provided on a display region on the substrate, and a partition wall defining a region in which the plurality of organic EL elements are disposed and a contact hole provided outside the display region The plurality of organic EL elements include a first electrode, a second electrode that is further apart from the substrate than the first electrode, and a layer or a plurality of layers that are provided between the first electrode and the second electrode. In the organic EL layer, the second electrode has a connection portion extending from the display region to the contact hole on the partition wall, and an end portion of the partition wall on the substrate side, a side surface of the partition wall in the display region The angle formed by the bottom surface of the partition wall is an obtuse angle, and a display device in which an angle formed by a side surface of the partition wall and a bottom surface of the partition wall is an acute angle in a region where the contact hole is formed.

The display device mainly includes an active matrix drive type device and a passive matrix drive type device. The present invention is applicable to both types of display devices. However, this embodiment describes an example of a configuration suitable for an active matrix drive type display device.

<Configuration Example of Display Device>

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

As shown in FIGS. 1 to 4, the display device 1 includes a substrate 2 and a plurality of organic EL elements provided in the display region 30 of the substrate 2. And a partition wall 3 defining a contact hole provided outside the display region 30 while defining a display region 30 provided with a plurality of organic EL elements 4.

As shown in FIG. 1, the display area 30 and the contact area 31 are set on the substrate 2.

As shown in FIG. 2, a plurality of organic EL elements 4 (pixels) are provided in the display area 30. The partition wall 3 of the present embodiment is provided on the substrate 2 so as to cover the display region 30 and the region other than the contact region 31.

The partition wall 3 of the present embodiment is provided in a lattice shape in the display region 30. Further, in another embodiment, for example, the partition wall 3 is provided in a stripe shape in the display region 30.

The organic EL elements 4 are each provided in a region surrounded by the lattice-shaped partition walls 3.

A plurality of recesses 5 defined by the partition walls 3 and the substrate 2 are disposed on the substrate 2. A plurality of organic EL elements 4 are provided in each of the plurality of concave portions 5.

Since the partition walls 3 of the present embodiment are arranged in a lattice shape, the plurality of concave portions 5 are arranged in a matrix form when viewed from one of the thickness directions Z of the substrate 2 (hereinafter, referred to as "planar viewing angle"). That is, the plurality of concave portions 5 are provided in such a manner that the row direction X is arranged at a predetermined interval and the row direction Y is also arranged at a predetermined interval. The shape of each of the plurality of concave portions 5 in the plane view angle is not particularly limited. For example, the recess 5 may be formed in a substantially rectangular shape or a slightly rounded shape in a plan view. This embodiment is provided with a plurality of concave portions 5 having a substantially rectangular shape in plan view. In addition to this In the specification, the "column direction X" and the "row direction Y" are perpendicular to the thickness direction Z of the substrate, and are perpendicular to each other.

Further, when the stripe-shaped partition walls 3 are provided as another embodiment, the partition walls 3 are arranged, for example, in a plurality of partition wall members extending in the column direction X so as to be arranged at a predetermined interval in the row direction Y. In this form, the strip-shaped recesses 5 are defined by the strip-shaped partition walls 3 and the substrate 2.

As shown in Fig. 3, the end portion 3a of the partition wall 3 on the substrate 2 side is cut in the display region 30 by a recess 5 defined by the partition wall 3 in a plane extending in the thickness direction of the partition wall 3. In the region, the angle θ 1 formed by the side surface of the partition wall 3 defining the recess 5 and the bottom surface of the partition wall 3 is formed to be an obtuse angle. The end portion 3a is, for example, a form in which the width of the cross section when the partition wall 3 extending in the row direction Y is cut in a plane perpendicular to the direction in which it extends (the row direction Y) becomes larger as it goes away from the substrate 2.

In the display region 30, the angle θ 1 formed by the side surface of the partition wall 3 and the surface of the substrate 2 (the bottom surface of the partition wall 3), that is, the inclination angle θ 1 of the side surface of the partition wall 3 is about 95° to 170°. Good for 100° to 120°. Further, the partition wall 3 whose inclination angle θ 1 of the side surface of the partition wall 3 is 0° to 90° is called a so-called tapered shape partition wall, and the inclination angle θ 1 of the side surface of the partition wall 3 is 90°. The partition wall 3 up to 180° is called a so-called inverted tapered shape partition wall. That is, the display region 30 of the present embodiment is provided with the partition wall 3 having an inverted tapered shape.

Further, an end portion 3b opposite to the substrate 2 side of the partition wall 3 is preferably attached to the display region 30 with the side surface of the partition wall 3 and the partition wall The angle formed by the bottom surface of 3 is formed by an acute angle. In other words, the partition wall 3 is not always formed in a reverse tapered shape from the end portion 3a on the substrate 2 side to the end portion 3b on the side opposite to the substrate 2 side, and the end portion 3a on the substrate 2 side is reversely tapered. The shape is formed, and the end portion 3b on the side opposite to the side of the substrate 2 is preferably formed in a forward tapered shape. Such a shape can more effectively prevent the disconnection of the second electrode 10 in the boundary region between the partition wall 3 and the organic EL layers 7, 9.

The organic EL element 4 is provided in a section (that is, the recess 5) drawn by the partition 3 and the substrate 2. When the lattice-shaped partition walls 3 are provided as in the present embodiment, the plurality of organic EL elements 4 are provided in the plurality of concave portions 5, respectively. In other words, the organic EL elements 4 are arranged in a matrix in the same manner as the respective concave portions 5, and are arranged on the substrate 2 at predetermined intervals in the column direction X, and are also arranged in the row direction Y at predetermined intervals.

In addition, when the stripe-shaped partition walls are provided as the other embodiment, the organic EL elements 4 are arranged in the respective recessed portions 5 extending in the column direction X, and are arranged in the column direction X at predetermined intervals.

In the present embodiment, three types of organic EL elements 4 of luminescent colors are provided. That is, (1) a red organic EL element 4R that emits red light, (2) a green organic EL element 4G that emits green light, and (3) a blue organic EL element 4B that emits blue light.

As shown in Fig. 2, the three types of organic EL elements 4 (red organic EL element 4R, green organic EL element 4G, and blue organic EL element 4B) are, for example, the following column (I), column (II) ), the column (III) is repeatedly arranged in this order in the row direction Y, thereby arranging the red organic EL elements 4R individually, The green organic EL element 4G and the blue organic EL element 4B are arranged.

(I) The red organic EL element 4R is arranged in such a manner that the column directions X are arranged at predetermined intervals.

(II) The green organic EL element 4G is arranged in such a manner that the column directions X are arranged at predetermined intervals.

(III) The blue organic EL element 4B is arranged in such a manner that the column directions X are arranged at predetermined intervals.

Further, as another embodiment, in addition to the above-described three types of organic EL elements 4, for example, an organic EL element that emits white light may be further provided. Further, only one type of organic EL element 4 may be provided to realize a monochrome display device.

The organic EL element 4 includes a first electrode 6, a second electrode 10 provided away from the substrate 2 from the first electrode 6, and a layer provided between the first electrode 6 and the second electrode 10 or A plurality of layers of organic EL layers. In the present specification, one layer or a plurality of layers provided between the first electrode 6 and the second electrode 10 are each referred to as an organic EL layer. The organic EL element 4 has at least one light-emitting layer as an organic EL layer. In addition to the one-layer light-emitting layer, the organic EL element 4 may further include an organic EL layer different from the light-emitting layer, as needed. For example, a hole injection layer, a hole transport layer, an electron blocking layer, an electron transport layer, and an electron injection layer which are organic EL layers may be provided between the first electrode 6 and the second electrode 10. Further, two or more light-emitting layers may be provided between the first electrode 6 and the second electrode 10.

The organic EL element 4 includes a pair of electrodes, that is, a first electrode 6 and a second electrode 10, which are formed by an anode and a cathode. The first electrode 6 is One of the electrodes of the second electrode 10 is an anode, and the other electrode is a cathode.

In the example of the organic EL device of the present embodiment, the first electrode 6 which functions as an anode function, the first organic EL layer 7 which functions as a hole injection layer, the second organic EL layer 9 which functions as a light-emitting layer, and the cathode are used. The organic EL element 4 in which the second electrode 10 of the function is laminated on the substrate 2 in this order will be described.

In the present embodiment, three types of organic EL elements are provided, but the respective structures are different from those of the second organic EL layer 9 as a light-emitting layer. The red organic EL element 4R includes a red light-emitting layer 9R that emits red light, the green organic EL element 4G includes a green light-emitting layer 9G that emits green light, and the blue organic EL element 4B includes a blue light-emitting layer 9B that emits blue light.

The first electrode 6 of the present embodiment is provided for each of the organic EL elements 4. That is, the same number of the first electrodes 6 as the organic EL elements 4 are provided on the substrate 2. The first electrode 6 is provided in accordance with the arrangement of the organic EL elements 4, and is arranged in a matrix form overlapping the first organic EL layer 7 and the second organic EL layer 9 in a plan view. Further, the partition wall 3 of the present embodiment is mainly formed in a lattice shape in a region other than the first electrode 6, but may be provided so as to cover a part of the first electrode 6 so as to cover the peripheral edge portion of the first electrode 6.

The first organic EL layer 7 corresponding to the hole injection layer is provided on each of the plurality of first electrodes 6 in the recess 5. The first organic EL layer 7 is provided with a different material or thickness depending on the type (light-emitting color) of each of the organic EL elements 4 as needed. Further, the step of forming from the first organic EL layer 7 From the viewpoint of simplicity, all of the first organic EL layers 7 may be formed of the same material and the same thickness.

The second organic EL layer 9 that functions as a light-emitting layer is provided on the first organic EL layer 7 of the concave portion 5. As described above, the light-emitting layer is provided corresponding to the type of the organic EL element. Therefore, the red light-emitting layer 9R is provided in the concave portion 5 in which the red organic EL element 4R is provided, the green light-emitting layer 9G is provided in the concave portion 5 in which the green organic EL element 4G is provided, and the blue light-emitting layer 9B is provided in the blue organic EL. The recess 5 of the element 4B.

The second electrode 10 is formed to cover the entire surface of the display region where the organic EL element 4 is provided. In other words, the second electrode 10 is provided not only on the second organic EL layer 9, but also on the partition wall 3, and is integrally provided continuously across the plurality of organic EL elements 4, that is, the plurality of recesses 5.

As shown in FIG. 3, the surface of the second electrode 10 on the side of the substrate 2 is preferably separated from the substrate 2 from the central portion C of the organic EL element 4 to the partition wall 3. In other words, the surface (interface) formed by the organic EL layer 9 and the partition wall 3 that is in contact with the second electrode 10 is preferably from the central portion C of the plane view of the organic EL element 4 to the partition wall 3, And slowly away from the substrate 2. By configuring the surface of the organic EL layer 9 and the partition wall 3 that are in contact with the second electrode 10, it is possible to effectively prevent the second electrode 10 from being broken near the interface between the organic EL layer 9 and the partition wall 3. .

The partition wall 3 of the above embodiment covers the peripheral edge portion of the first electrode 6 and is provided in contact with the substrate 2. However, in another embodiment, an insulating film may be further provided between the partition wall 3 and the substrate 2. Insulating film system For example, it can be provided in a lattice shape in a plan view like the partition wall, and can be provided so as to cover the peripheral edge portion of the first electrode 6. Such an insulating film is preferably formed of a material exhibiting more lyophilic properties than the partition walls 3.

As shown in Fig. 1, the contact region 31 of the present embodiment is provided to extend in the row direction Y at a position away from one side (the left side in the first drawing) of the display region 30 in the column direction X. Further, the contact area refers to a region in which a contact hole and a contact conductor buried in the contact hole are provided. Further, in the present embodiment, the contact region 31 is provided to extend in the row direction Y at a position away from the other side (the right side in the first drawing) of the column direction X of the display region 30.

As shown in Fig. 4, the region (contact region 31) on which the contact hole is formed is on the end portion of the partition wall 3 on the substrate 2 side (the lower end portion in Fig. 4), and extends in the thickness direction of the partition wall 3. When the region including the contact region 31 is cut by the plane, the angle θ 2 formed by the side surface of the partition wall 3 defining the contact hole and the bottom surface of the partition wall 3 is set to an acute angle. That is, in the present embodiment, the partition wall 3 having a tapered shape is provided in a region where the contact hole is formed. θ 2 is from about 5° to about 85°, preferably from about 20° to about 60°.

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

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

The second electrode 10, the connection portion 23, and the contact conductor 22 are integrally provided in this manner, and the contact conductor 22 is connected to the electrode wiring 20. 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.

5A to 8B are schematic cross-sectional views showing a display device in the middle of formation shown in the method of manufacturing the display device. 5A to 6C show the area shown in Fig. 3 (display area 30), and Figs. 7A to 8B show the area corresponding to Fig. 4 (contact area 31).

(Steps for preparing the 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 addition, in this step, the substrate 2 on which the first electrode 6 and the electrode wiring 20 are formed may be prepared by obtaining a substrate on which the first electrode 6 and the electrode wiring 20 are provided from the market (hereinafter, the electrode wiring 20 may be formed in some cases). The substrate 2 of a predetermined structure is simply referred to as a substrate 2).

When the display device is of the active matrix type, a substrate in which a circuit for individually driving a plurality of organic EL elements is 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), a capacitor, or the like is formed in advance can be used as the substrate 2.

First, a plurality of first electrodes 6 are formed in a matrix on the substrate 2, and the electrode wirings 20 are formed at predetermined positions. The first electrode 6 is formed by, for example, forming a conductive thin film on one surface of the substrate 2, and patterning the conductive thin film in a matrix shape by a patterning step using a conductive thin film formed by a photolithography method. And formed. Further, for example, a photomask having an opening formed in a predetermined portion on the substrate 2 may be disposed, and a conductive material may be selectively deposited on a predetermined portion of the substrate 2 through the photomask to form the first electrode 6 in a predetermined pattern. Further, the electrode wiring 20 is formed in the same manner as the first electrode 6, for example, in the same step as the first electrode 6, together with the first electrode 6. The material of the first electrode 6 and the electrode wiring 20 will be described later (see FIG. 5A and FIG. 7A).

(step of forming a partition wall)

In this step, an ink (solution) containing a negative-type photoresist material (photosensitive resin) is applied onto a substrate to form a film for forming a partition wall, and the exposure amount is different between the display region and the region where the contact hole is provided. The partition wall 3 is formed by patterning and developing a film for forming a partition wall. Further, a region in which a contact hole is provided refers to a region including a region where the contact conductor 22 is provided and a peripheral portion of the region where the contact conductor 22 is provided.

First, an ink containing a photosensitive resin is applied onto the substrate 2 to form a film for forming a partition wall 8 (see FIGS. 5B and 7B).

The coating method of the ink can be, for example, a spin coating method or a slit coating method.

After the ink containing the photosensitive resin is applied onto the substrate 2, a prebaking step is usually performed. Pre-baking step, for example by 80 ° C The substrate is heated to a temperature of 110 ° C for 60 seconds to 180 seconds, and the solvent is removed to form the film for forming a partition wall 8 .

As shown in FIG. 5C, a photomask 21 (first photomask 21a) that blocks light 100 of a predetermined pattern is placed on the substrate 2 on which the partition wall forming film 8 is provided, and the spacer 21 is formed through the photomask 21. Exposure was carried out using the film 8. The photosensitive resin has a positive type and a negative type photosensitive resin. However, in this step, a negative type photosensitive resin is used. When the negative photosensitive resin is used, the portion 100 in which the partition wall 3 is mainly formed in the film for partition wall formation 8 is irradiated with light 100.

Further, in the present embodiment, the region in which the organic EL element is provided and the region in which the contact hole is provided expose the partition wall forming film 8 with a different exposure amount. Thus, the exposure amount is different, and the partition wall 3 having an inverted tapered shape can be formed in the display region 30, and the partition wall 3 having a tapered shape can be formed in the contact region 31.

Specifically, when a proximity exposure machine in which exposure cannot be divided is used, two masks 21 are used, and exposure is performed twice for each predetermined exposure region. Thereby, the exposure amounts of the respective exposure regions can be made different.

Further, when a stepper capable of splitting exposure is used, one reticle 21 can be used, and the exposure amount is changed corresponding to the exposure area, thereby making the exposure amount different.

In the present embodiment, an example of using a proximity exposure machine in which exposure cannot be divided is specifically described. In this case, the exposure area is divided into a first exposure area and a second exposure area, and exposure is divided into two times using two types of photomasks 21 corresponding to the respective exposure areas.

Figure 9 is a view showing a display device for an exposed area Schematic plan. In the present embodiment, the first exposure region corresponds to the display region 30 and the peripheral edge portion 32 surrounding the display region 30. The second exposure area corresponds to an area other than the display area 30. That is, the second exposure region includes the contact region 31. Further, in this case, the first exposure region and the second exposure region overlap each other in the peripheral edge portion 32 of the display region 30. Therefore, the peripheral portion 32 of the display region 30 is exposed twice.

First, the exposure of the first exposure region is performed. As shown in FIG. 5C, the first photomask 21a is placed on the substrate 2, and the light 100 is irradiated through the first photomask 21a. The partition wall 3 is mainly formed in the partition wall forming film 8 in the first exposure region. The area is irradiated with light 100 at the first exposure amount. In the fifth embodiment, the light 100 that is irradiated onto the partition wall forming film 8 is schematically indicated by a white arrow. Further, in this step, the light of the contact region 31 is blocked by the first photomask 21a.

Next, exposure of the second exposure region is performed. As shown in FIG. 7C, the second photomask 21b is placed on the substrate 2, and the light 100 is irradiated through the photomask 21b, so that the partition wall 3 is mainly formed in the partition wall forming film 8 in the second exposure region. The portion, that is, the region other than the contact region 31, illuminates the light with the second exposure amount. In the seventh embodiment, the light 100 irradiated to the partition wall forming film 8 is schematically indicated by a white arrow. Further, in this step, the light in the contact region 31 and the display region 30 is blocked by the second photomask 21b.

Further, in a region where the first exposure region and the second exposure region overlap, the amount of light accumulated by the first exposure amount and the second exposure amount is irradiated.

In general, in the case of a negative photosensitive resin, the more the exposure amount, the smaller the inclination angles θ 1, θ 2 of the side walls of the partition walls tend to be smaller. The first exposure amount here is set to be smaller than the exposure amount of the second exposure amount. The first exposure amount is set corresponding to the inclination angle θ 1 , for example, 20 mJ/m ² to 60 mJ/m ² , preferably 20 mJ/m ² to 40 mJ/m ² .

Second exposure amount corresponding to the desired line of the inclination angle [theta] 2 and provided, for example, 60mJ / m ² to 200mJ / m ^2, preferably 80mJ / m ² to 100mJ / m ^2.

Further, the inclination angles θ 1, θ 2 can also be adjusted by adjusting the development time. In general, in the case of a negative photosensitive resin, the longer the development time, the higher the inclination angles θ 1, θ 2 tend to become larger. Further, the inclination angle θ 1, θ 2 can be adjusted by adjusting the distance between the reticle and the substrate 2. In general, in the case of a negative photosensitive resin, the shorter the distance between the mask and the substrate 2, the closer the inclination angles θ 1, θ 2 are to 90°.

Further, the inclination angles θ 1, θ 2 are also related to the thickness of the partition wall forming film 8. Here, the thickness of the partition wall forming film 8 is preferably from 0.5 μm to 1 μm, more preferably from 0.6 μm to 0.7 μm.

Next, development is carried out. Thereby, the partition 3 pattern is formed (refer to FIG. 6A and FIG. 8A). After development, a post-baking step is performed as needed. The post-baking step is performed, for example, at a temperature of 200 ° C to 230 ° C for 15 minutes to 60 minutes by heating the substrate forming the pattern of the partition walls 3 to further harden the partition walls 3 .

The partition wall 3 is formed in the above manner, and the display region 30 is formed with the partition wall 3 having an inverted tapered shape, and the contact region 31 is formed with the partition wall 3 having a tapered shape.

In the composition (solution) of the photosensitive resin used for forming the partition, a composition containing a binder resin, a crosslinking agent, a photoreaction initiator, a solvent, an ultraviolet absorber, and other additives is generally used.

As the binder resin, a polymer which is previously polymerized can be used. Examples of the binder resin include a non-polymerizable binder resin which does not have polymerizability, and a polymerizable binder resin which introduces a polymerizable substituent. The binder resin is a polystyrene-based standard and has a weight average molecular weight of 5,000 to 400,000 as determined by gel permeation chromatography (GPC).

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. The binder resin-based monomers may be used singly or in combination of two or more kinds of copolymers. The content of the binder resin is usually from 5% to 90% by mass based on the total solid matter of the above-mentioned ink containing the photosensitive resin.

The crosslinking agent is a compound polymerizable by irradiation of light by an active radical, an acid or the like generated from a photopolymerization initiator. The crosslinking agent may, for example, be a compound having a polymerizable carbon-carbon unsaturated bond. The crosslinking agent may be a monofunctional compound having one polymerizable carbon-carbon unsaturated bond in the molecule, or a bifunctional or trifunctional or higher having two or more polymerizable carbon-carbon unsaturated bonds. Polyfunctional compound. In the ink containing the photosensitive resin, the crosslinking agent is generally 0.1 parts by mass or more and 70 parts by mass or less, based on 100 parts by mass of the total amount of the binder resin and the crosslinking agent. Further, in the above ink containing a photosensitive resin, the photoreaction initiator is When the total amount of the binder resin and the crosslinking agent is 100 parts by mass, it is usually 1 part by mass or more and 30 parts by mass or less.

Specifically, ZPN 2464 manufactured by Zeon Co., Ltd., Japan can be used as the negative photosensitive resin composition.

Further, a liquid repellent agent may be mixed in the photosensitive resin composition to prepare a photosensitive resin composition containing the liquid repellent. For the liquid-repellent agent, for example, a large gold liquid dispensing agent opto ace (registered trademark) HP series can be used. The solid content concentration ratio of the liquid-repellent agent with respect to the total solid content of the photosensitive resin composition other than the liquid-repellent agent {(liquid-repellent agent/solid-solid fraction of the photosensitive resin composition other than the liquid-repellent agent) × 100} is preferably from 0.1% to 1.0% by mass.

The light 100 (irradiation light) irradiated to the photosensitive resin composition is absorbed by the ultraviolet absorber or the like, and becomes weaker as it goes away from the surface side. Therefore, the light-irradiated side (surface side) of the photosensitive resin composition which is applied and exposed is easily cured, and the more difficult it is to harden from the surface side. Therefore, the vicinity of the bottom surface (on the substrate 2 side) where the exposure amount is hard to reach is hard to be hardened, and the developer is exposed to the developer, so that the shape of the side surface of the partition wall 3 has a reverse tapered shape. On the other hand, when the photosensitive resin composition is irradiated with light at an exposure amount sufficient for curing in the entire thickness direction, it can be formed into a tapered shape.

The developing solution used for development may, for example, be an aqueous solution of potassium chloride or an aqueous solution of tetramethylammonium hydroxide (TMAH).

The shape of the partition wall 3 and the arrangement thereof are appropriately set in accordance with the specifications of the display device such as the number of pixels and the resolution, ease of manufacture, and the like. The column direction X of the partition wall 3 of the display area 30 or the width of the row direction Y The degree is, for example, about 5 μm to 50 μm, and the height (thickness) of the partition wall 3 is about 0.3 μm to 5 μm, and the interval between the partition walls 3 adjacent to each other in the column direction X or the row direction Y, that is, the column direction of the concave portion 5 The width of the X or the row direction Y is about 10 μm to 200 μm. Further, the widths of the first electrode 6 in the column direction X or the row direction Y are each about 10 μm to 200 μm.

The width of the row X of the contact holes of the partition walls 3 in the contact region 31 is about 3 μm to 5000 μm.

(Step of forming an organic EL layer)

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

First, the ink containing the material which becomes the first organic EL layer 7 is supplied (coated) to the region (recess 5) surrounded by the partition wall 3. The ink is supplied in an appropriate and optimum manner in consideration of the shape of the partition wall 3, the ease of the formation step, and the film formability. The ink is supplied by, for example, an inkjet printing method, a nozzle coating method, a letterpress printing method, a gravure printing method, or the like.

Next, the first organic EL layer 7 is formed by curing the supplied ink. The curing of the ink can be carried out, for example, by natural drying, heat drying, and vacuum drying. Further, when the ink contains a material polymerized by application of energy, the material constituting the organic EL layer may be polymerized by heating the film or irradiating the film after the ink is supplied. By polymerizing the material constituting the organic EL layer, the organic EL layer can be hardly melted 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. Alternatively, three types of inks (the red ink for forming the red light-emitting layer 9R) containing the red light-emitting layer 9R, the green light-emitting layer 9G, and the blue light-emitting layer 9B may be used to form the green light-emitting layer 9G. The green ink, the blue ink for forming the blue light-emitting layer 9B, is separately supplied to the region surrounded by the partition wall 3, and further, by solidifying it, a red light-emitting layer 9R, a green light-emitting layer 9G, and a blue color are formed. Light-emitting layer 9B.

When the organic EL layer is formed by the coating method as described above, since the partition wall having the inverted tapered shape is provided, the ink supplied to the region (the recess 5) surrounded by the partition wall 3 is sucked by capillary action. The first electrode 6 is connected to the portion 7a having a tapered end portion before the partition wall 3. By maintaining this state, the solvent of the ink is evaporated, and an organic EL layer is also formed at a 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.

Then, the material constituting the organic EL layer 7 is filled in a portion 7a having a tapered end before the connection between the first electrode 6 and the partition 3, and the organic EL layer 9 and the partition 3 which are in contact with the second electrode 10 are formed. The surface (the surface of the organic EL layer 7) is formed away from the substrate 2 in the planar viewing angle as it goes from the central portion C of the organic EL element 4 to the partition wall 3.

(Step of forming the second electrode or the like)

Next, the entire area except for the predetermined area of the substrate 2 (at least the display area 30 and the contact area 31, and the display area 30 and the contact area 31) A region between the layers) forms a conductive film. Thereby, the second electrode 10, the connection portion 23, and the contact conductor 22 are formed.

In the present embodiment, since the partition wall 3 is formed in a tapered shape in the contact region 31, even when the thickness of the connecting portion 23 and the contact conductor 22 is thin, the ends of the partition wall 3 can be prevented from being broken.

Further, in the display region 30, the partition wall 3 is formed in an inverted tapered shape, but the end portion on the substrate 2 side (near the tip end portion 7a) of the region surrounded by the partition wall 3 is composed of the organic EL layer 7, 9 Since the material is filled, even when the thickness of the second electrode 10 is thin, the second electrode 10 can be prevented from being broken at the end of the partition wall 3.

In this manner, the partition wall 3 is formed into a tapered shape by the contact region 31, and the partition wall 3 is formed into an inverted tapered shape in the display region 30, whereby the thickness of the second electrode 10, the connecting portion 23, and the contact conductor 22 can be thinned, and Compared to the prior art, the time required to form the elements can be shortened.

The thickness of the second electrode 10, the connection portion 23, and the contact conductor 22 is set in consideration of necessary resistance and film formation time, such as 10 nm to 1 μm, preferably 50 nm to 500 nm, and more preferably 100 nm to 200 nm.

Further, as described above, the surface of the second electrode 10 on the side of the substrate 2 is formed to be away from the substrate 2 in accordance with the central portion C from the plane view of the organic EL element 4 to the partition wall 3. In other words, the surface of the organic EL layer 9 and the partition wall 3 (the surface of the organic EL layer 9) which is in contact with the second electrode 10 is close to the central portion C from the plane of view of the organic EL element 4. The partition wall 3 is formed in such a manner as to be distant from the substrate 2. By the organic EL layer 9 connected to the second electrode 10 The surface of the partition wall 3 is configured in such a manner as to prevent the second electrode 10 from being broken at the boundary region between the organic EL layer 9 and the partition wall 3.

<Composition of organic EL elements>

Hereinafter, the configuration of the organic EL device of the present embodiment will be described in detail. The organic EL element has at least one light-emitting layer as an organic EL layer, but as described above, the organic EL layer may further include, for example, a hole injection layer, a hole transport layer, an electron blocking layer, a hole blocking layer, and an electron transport layer. , as well as electron injection layers.

The example of the layer configuration of the organic EL device of the present embodiment is as follows.

a) anode / luminescent layer / cathode

b) anode / hole injection layer / luminescent layer / cathode

c) anode / hole injection layer / luminescent layer / electron injection layer / cathode

d) anode/hole injection layer/light-emitting layer/electron transport layer/electron injection layer/cathode

e) anode/hole injection layer/hole transport layer/light-emitting layer/cathode

f) anode/hole injection layer/hole transport layer/light-emitting layer/electron injection layer/cathode

g) anode/hole injection layer/hole transport layer/light-emitting layer/electron transport layer/electron injection layer/cathode

h) anode / luminescent layer / electron injection layer / cathode

i) anode / luminescent layer / electron transport layer / electron injection layer / cathode

Here, the symbol "/" means that the layers sandwiching the symbol "/" are joined to each other.

Further, in the above embodiment, the first electrode 6 exhibiting the anode function is disposed in the vicinity of the substrate 2 with respect to the second electrode 10. In the case of the organic EL device of the form, the present invention is also applicable to an organic EL device in which the first electrode 6 of the cathode function is disposed in the vicinity of the substrate 2 with respect to the second electrode 10. Further, the organic EL element is, for example, in the layer configuration of the above a) to i), and may be provided in such a manner that the substrate 2 is sequentially disposed from the anode, the cathode is provided in the uppermost layer, or the substrate 2 is sequentially disposed from the cathode. The anode is placed in the uppermost layer. Hereinafter, each constituent element relating to the above layer configuration will be described.

<Substrate>

The substrate 2 is preferably used without any chemical change in the step of producing the organic EL element. For the substrate 2, for example, a glass substrate, a plastic substrate, a polymer film substrate, a tantalum substrate, and a substrate laminated thereon may be used.

<anode>

When the light emitted from the light-emitting layer is emitted through the anode and emitted to the external organic EL element, an electrode exhibiting light transmittance can be used for the anode. As the electrode which exhibits light transmittance, a film of a metal oxide, a metal sulfide, or a metal can be used, and a conductivity and a light transmittance can be suitably used. Specifically, indium oxide, zinc oxide, tin oxide, indium tin oxide (hereinafter referred to as ITO), indium zinc oxide (Indium Zinc Oxide, hereinafter referred to as IZO), gold, or the like can be used. A film composed of platinum, silver, copper, or the like may be suitably used as a film composed of ITO, IZO, or tin oxide. Examples of the method for producing the anode include a vacuum deposition method, a sputtering method, an ion plating method, and a plating method. Further, as the anode, a transparent conductive film containing an organic material such as polyaniline or a derivative thereof, polythiophene or a derivative thereof can be used.

<cathode>

The material of the cathode is preferably a material having a small work function and easy to inject electrons into the light-emitting layer and having high conductivity. Further, in the organic EL device having the light-removing light from the anode side, in order to reflect the light emitted from the light-emitting layer to the anode side as a cathode, the material of the cathode is preferably a material having a high reflectance for visible light. As the cathode system, for example, an alkali metal, an alkaline earth metal, a transition metal, a metal of Group 13 of the periodic table, or the like can be used. As the material of the cathode, for example, metals such as lithium, sodium, potassium, rubidium, cesium, cesium, magnesium, calcium, strontium, barium, aluminum, strontium, vanadium, zinc, bismuth, indium, antimony, bismuth, antimony, bismuth, antimony, and the like can be used. Two or more kinds of the above-mentioned metals, one or more of the above metals, and one or more alloys of gold, silver, platinum, copper, manganese, titanium, cobalt, nickel, tungsten, and tin, or graphite Or a graphite intercalation compound or the like. Examples of the alloy include a magnesium-silver alloy, a magnesium-indium alloy, a magnesium-aluminum alloy, an indium-silver alloy, a lithium-aluminum alloy, a lithium-magnesium alloy, a lithium-indium alloy, and a calcium-aluminum alloy. Further, a transparent conductive electrode made of a conductive metal oxide, a conductive organic substance or the like can be used as the cathode. Specifically, the conductive metal oxide may, for example, be indium oxide, zinc oxide, tin oxide, ITO or IZO, and the conductive organic material may, for example, be polyaniline or a derivative thereof, or polythiophene or a derivative thereof. Further, the cathode system may be composed of a laminate of two or more layers. Further, the electron injecting layer also serves as a cathode.

Examples of the method for producing the cathode include a vacuum deposition method, an ion plating method, and the like.

The thickness of the anode or the cathode can be appropriately set in consideration of the required characteristics, the ease of the production steps, and the like. Anode or cathode thickness The system is, for example, 10 nm to 10 μm, preferably 20 nm to 1 μm, more preferably 50 nm to 500 nm. Further, the electrode as the second electrode in the anode and the cathode is as described above, and the thickness thereof is set in consideration of necessary resistance and production time, such as 10 nm to 1 μm, preferably 50 nm to 500 nm, and more preferably 100 nm to 200 nm.

Further, the electrode wiring 20, the connection portion 23, and the contact conductor 22 can be fabricated using materials exemplified as materials for the cathode and the anode. Further, the connecting portion 23 and the contact conductor 22 are preferably formed in the same step using the same material as the second electrode 10. Further, although the electrode wiring 20 is not required to have the same material as that of the first electrode 6 or the second electrode 10, it is preferably smaller than the electric resistance of the first electrode 6 or the second electrode 10, and is preferably connected to the contact conductor 22. The contact resistance is small.

<hole injection layer>

Examples of the hole injecting material constituting the hole injecting layer include oxides such as vanadium oxide, molybdenum oxide, cerium oxide, and aluminum oxide, phenylamine compounds, starburst type amine compounds, phthalocyanine compounds, and non- Crystal carbon, polyaniline and polythiophene derivatives.

The manufacturing method of the hole injection layer is, for example, a coating step using a solution containing a hole injecting material. The hole injection layer is formed by, for example, applying a solution containing a hole injecting material by a predetermined coating method, and further forming a hole injecting layer by curing.

The thickness of the hole injection layer is appropriately set in consideration of the characteristics required for the hole and the ease of the steps. The thickness of the hole injection layer is, for example, 1 nm to 1 μm, preferably 2 nm to 500 nm, and more preferably 5 nm to 200 nm.

<hole transport layer>

The hole transporting material constituting the hole transporting layer may, for example, be a polyvinylcarbazole or a derivative thereof, a polydecane or a derivative thereof, a polyoxyalkylene derivative having an aromatic amine structure in a side chain or a main chain, and pyridyl An oxazoline derivative, an arylamine derivative, a stilbene derivative, a triphenyldiamine derivative, a polyaniline or a derivative thereof, a polythiophene or a derivative thereof, a polyarylamine or a derivative thereof, a polypyrrole Or a derivative thereof, poly(p-phenylenevinyl) or a derivative thereof, or poly(2,5-thretended thiophenevinyl) or a derivative thereof.

The thickness of the hole transport layer is set by considering the characteristics required, the ease of the production steps, and the like. The thickness of the hole transport layer is, for example, 1 nm to 1 μm, preferably 2 nm to 500 nm, and more preferably 5 nm to 200 nm.

<Light Emitting Layer>

The light-emitting layer system generally mainly contains an organic material (light-emitting material) that emits fluorescence and/or phosphorescence, or a dopant material that is supplemented with the organic material. The dopant material is added, for example, to increase the luminous efficiency and change the wavelength of the light. Further, the organic material constituting the light-emitting layer may be a low molecular compound or a polymer compound, and when the light-emitting layer is formed by a coating method, the material of the light-emitting layer preferably contains a polymer compound. The polystyrene-equivalent number average molecular weight of the polymer compound constituting the light-emitting layer is, for example, about 10 ³ to 10 ⁸ . Examples of the light-emitting material constituting the light-emitting layer include the following pigment materials, metal complex materials, polymer materials, and dopants.

(pigment material)

Examples of the pigment material include a cyclopentamine derivative, a tetraphenylbutadiene derivative, and a triphenylamine derivative. Diazole derivative, pyrazoloquinoline derivative, distyrylbenzene derivative, distyryl extended aryl derivative, pyrrole derivative, compound containing thiophene ring structure, compound containing pyridine ring structure, purple ring Perinone derivatives, anthracene derivatives, oligothiophene derivatives, An oxadiazole dimer, a pyrazoline dimer, a quinacridone derivative, a coumarin derivative or the like.

(metal complex material)

The metal complex material may, for example, have a rare earth metal such as Tb, Eu or Dy, or Al, Zn, Be, Ir, Pt or the like in the central metal, and have a ligand A metal complex such as an oxadiazole, a thiadiazole, a phenylpyridine, a phenylbenzimidazole or a quinoline structure, for example, having a triplet excited state derived from a ruthenium complex or a platinum complex. Metal complex, aluminum quinolinol complex, benzoquinoline phenolphthalein complex, benzo An azolyl zinc complex, a benzothiazole zinc complex, an azomethyl zinc complex, a zinc porphyrin complex, a morpholinium complex, and the like.

(Polymer Materials)

The polymer material may, for example, be a polyparaphenylene vinyl derivative, a polythiophene derivative, a polyparaphenylene derivative, a polydecane derivative, a polyacetylene derivative, a polyfluorene derivative, or a polyvinylcarbazole derivative. And a substance obtained by polymerizing the above-mentioned pigment material or metal complex material.

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

<Electronic transport layer>

As the electron transporting material constituting the electron transporting layer, a known material can be used. The electron transporting material constituting the electron transporting layer may, for example, An oxadiazole derivative, onion dimethane or a derivative thereof, benzoquinone or a derivative thereof, naphthoquinone or a derivative thereof, onion or a derivative thereof, tetracyano onion dimethane or a derivative thereof, an anthrone derivative , diphenyldicyanoethylene or a derivative thereof, a diphenoquinone derivative, or a metal complex of 8-hydroxyquinoline or a derivative thereof, polyquinoline or a derivative thereof, polyquine Porphyrin or a derivative thereof, polyfluorene or a derivative thereof, and the like.

The thickness of the electron transport layer is appropriately set in consideration of the characteristics required for the measurement, the ease of the production steps, and the like. The thickness of the electron transport layer is, for example, 1 nm to 1 μm, preferably 2 nm to 500 nm, and more preferably 5 nm to 200 nm.

<electron injection layer>

The material constituting the electron injecting layer is appropriately selected according to the type of the light emitting layer, and examples thereof include an alkali metal, an alkaline earth metal, an alloy containing one or more kinds of an alkali metal and an alkaline earth metal, an alkali metal or a base. Oxides, halides, carbonates, mixtures of such materials, and the like. Examples of the alkali metal, the alkali metal oxide, the halide, and the carbonate include lithium, sodium, potassium, rubidium, cesium, lithium oxide, lithium fluoride, sodium oxide, sodium fluoride, potassium oxide, and potassium fluoride. , cerium oxide, cerium fluoride, cerium oxide, cerium fluoride, lithium carbonate, and the like. Further, examples of the alkaline earth metal, the oxide of the alkaline earth metal, the halide, and the carbonate include, for example, magnesium, calcium, barium, strontium, magnesium oxide, magnesium fluoride, calcium oxide, calcium fluoride, barium oxide, and fluorine. Antimony, antimony oxide, antimony fluoride, magnesium carbonate, and the like. The electron injecting layer may be composed of a laminate of two or more layers, and examples thereof include a laminate of a LiF layer and a Ca layer.

The thickness of the electron injecting layer is preferably about 1 nm to 1 μm.

Each of the above organic EL layers can be coated by, for example, a nozzle A coating method such as a method, an inkjet printing method, a relief printing method, or a gravure printing method, a vacuum vapor deposition method, a sputtering method, or a CVD method. Further, when the organic EL layer is a plurality of layers, at least one organic EL layer is formed by a coating method.

Further, the coating method forms an organic EL layer by further applying an ink containing an organic EL material corresponding to each organic EL layer to further cure the applied ink. The solvent of the ink used in the coating method may, for example, be a chlorine solvent such as chloroform, dichloromethane or dichloroethane; an ether solvent such as tetrahydrofuran; an aromatic hydrocarbon solvent such as toluene or xylene; acetone or methyl ethyl ketone; Ketone solvent; ester solvent such as ethyl acetate, butyl acetate, ethyl cellosolve acetate, water, and the like.

[Examples]

The present embodiment will be more specifically described below by way of examples, but the present invention is not limited to the following examples.

(Example 1)

First, a first electrode (anode) including an ITO thin film and a TFT substrate in which an electrode wiring pattern is formed in advance are prepared (see FIGS. 5A and 7A).

Next, a negative-type photosensitive resin solution (ZPN2464, manufactured by Zeon Co., Ltd., Japan) was mixed with a liquid-repellent agent (Dajin liquid-repellent agent opto ace (registered trademark) HP series) to prepare a photosensitive resin to which a liquid-repellent agent was added. Solution. The concentration of the solid content of the liquid-repellent agent was 0.2% by weight with respect to the photosensitive resin. Next, a photosensitive resin solution to which a liquid-repellent agent was added was applied onto the surface of the prepared TFT substrate by spin coating, and further heated on a hot plate at 110 ° C for 90 seconds to carry out a prebaking treatment, and the solvent was evaporated. Coating film (see Fig. 5B and Fig. 7B).

Next, a photomask A (first photomask 21a) and a photomask B (second photomask 21b) for a proximity exposure machine are prepared. The mask A is exposed to an exposure amount of 40 mJ/cm ² in the first exposure region (the display region 30 and the peripheral edge portion 32 of the display region 30) (see FIG. 5C and FIG. 9). Subsequently, the mask B was used to expose at 80 mJ/cm ² in the second exposure region (region other than the display region 30) (see FIG. 7C and FIG. 9). Specifically, in the second exposure region, a region other than the contact region where the contact hole is formed is exposed. Thereafter, the film was exposed to light at 110 ° C for 60 seconds for baking (PEB) treatment. Subsequently, a developing solution (SD-1 (2.38 wt% of tetramethylammonium hydroxide (TMAH)) manufactured by Tokuyama Co., Ltd.) was used for rinsing and development for 50 seconds to remove the photosensitive resin in the unexposed portion. Further, it was heated at 230 ° C for 30 minutes to be a post-baking treatment, and the photosensitive resin was cured. Thereby forming a partition wall having an inverted conical shape in the display region and a recess defined by the same, and forming a partition wall having a tapered shape and being defined by the outside of the display region (including the contact region formed with the contact hole) Concave portion (see Fig. 6A and Fig. 8A).

The thickness of the partition wall was set to 0.7 μm in the thickness direction of the TFT substrate. As described above, the inclination angles θ 1, θ 2 of the side faces of the partition walls are also related to the thickness of the partition walls. When the thickness of the partition walls in the present embodiment is 0.7 μm, the exposure amount can be set to 40 mJ/cm ² or less. When the exposure amount is 80 mJ/cm ² or more, the partition wall having a tapered shape can form a partition wall having a tapered shape. In the display region 30, the angle θ 1 between the side surface of the partition wall 3 and the surface of the substrate (the bottom surface of the partition wall 3) is 150°.

In the region where the contact hole is provided, the angle θ 2 between the side surface of the partition wall 3 and the bottom surface of the partition wall 3 is 25°.

Further, the contact angle of the top surface (surface) of the partition wall with anisole is 50°. Further, the contact angle of the surface of the first electrode (ITO film) with pure water was 25°.

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

Next, an ink (Lithlex 142P manufactured by ULVAC Co., Ltd.) was used to ink (a solid concentration of 1.5% by weight of poly(ethylene dioxythiophene) (PEDOT) / polystyrene sulfonic acid (PSS) aqueous dispersion (Bayer) The AI4083)) is applied to each of the recesses.

Since the ink is plucked by the top surface of the partition wall having a high contact angle, the ink can be prevented from overflowing to the adjacent area along the top surface, and 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 portion where the tip end is thin before the first electrode and the partition wall by capillary action, and is uniformly diffused in the concave portion. Next, a hole injection layer having a nearly uniform thickness (50 nm) was formed by firing at 200 ° C (refer to Fig. 6B). The thickness here refers to the thickness of the central portion of the concave portion at a plane viewing angle.

Next, three types of light-emitting layers are formed. First, a polymer light-emitting material that emits red light is mixed with an organic solvent so as to have a concentration of 0.8% by weight to prepare an ink (red ink). Similarly, radiation will The green light-emitting luminescent material is mixed with an organic solvent in such a manner that its concentration is 0.8% by weight to prepare an ink (green ink). Then, the polymer light-emitting material emitting blue light was mixed in an organic solvent so as to have a concentration of 0.8% by weight to prepare an ink (blue ink). These red inks, green inks, and blue inks were each applied to a predetermined concave portion using an inkjet device (Litrex 142P manufactured by ULVAC Co., Ltd.). Since the ink is plucked by the top surface of the partition wall having a high contact angle, it does not overflow to the adjacent region (concave portion) along the top surface, and is accommodated in the concave portion. On the other hand, the ink accommodated in the concave portion is filled so as to be sucked into the portion where the tip end is thin before the first electrode and the partition wall by capillary action, and is uniformly diffused in the concave portion. Next, a light-emitting layer having a uniform thickness (60 nm) was formed by firing at 130 ° C (refer to Fig. 6B). Further, a light-emitting layer can also be formed using, for example, a polymer light-emitting material manufactured by Sumation Corporation.

Next, a layer made of NaF having a thickness of 2 nm, a layer made of Mg having a thickness of 2 nm, and a layer made of Al having a thickness of 200 nm were sequentially laminated by vacuum evaporation to form a second electrode made of Al ( Cathode), connection and contact conductor. Thereafter, the sealing substrate was bonded to the second electrode side, and the formed organic EL element was sealed to fabricate a display device.

The lower portion (substrate side) of the partition wall surrounding the pixel (organic EL element) after forming the light-emitting layer is buried by the material constituting the organic EL layer, and may be formed from the surface of the partition wall to the surface of the organic EL layer. The flat shape of the step difference. Therefore, a second electrode of Al having a total thickness of 200 nm was formed continuously over all of the organic EL elements. Thus, even if the periphery of the pixel is surrounded by the partition wall of the inverted cone shape, the cathode having a thinner thickness It will not be disconnected. Further, since the partition walls of the contact regions themselves are formed in a tapered shape, even if the connection portions and the contact conductors are thin, the wires are not broken. It was confirmed that the display device produced was normally illuminated in a display region in which a plurality of organic EL elements were provided.

1‧‧‧ display device

2‧‧‧Substrate

30‧‧‧Display area

31‧‧‧Contact area

Claims (4)

A display device includes: a substrate; a plurality of organic electroluminescent elements disposed on a display area on the substrate; and a region defining the plurality of organic electroluminescent elements and a contact hole disposed outside the display area The partition wall, wherein the plurality of organic electroluminescent elements have a first electrode, a second electrode that is further apart from the substrate than the first electrode, and a first electrode and the second electrode. a first or a plurality of layers of the organic electroluminescence layer, wherein the second electrode has a connection portion extending from the display region to the contact hole on the partition wall, and an end portion of the partition wall on the substrate side In the display area, an angle formed by a side surface of the partition wall and a bottom surface of the partition wall is an obtuse angle, and in a region where the contact hole is formed, an angle formed by a side surface of the partition wall and a bottom surface of the partition wall is Sharp angle. The display device according to claim 1, wherein an end portion on a side opposite to a substrate side of the partition wall is formed on a side surface of the partition wall and a bottom surface of the partition wall in the display region. The horn is an acute angle. The display device according to claim 1 or 2, wherein the surface of the second electrode on the substrate side is from the central portion of the organic electroluminescent device to the partition wall far from. A method of manufacturing a display device according to any one of claims 1 to 3, comprising: coating a negative photosensitive resin solution on a substrate to form a partition wall. The step of coating the film and the step of forming the partition wall by exposing and developing the coating film for forming the partition wall by differentiating the exposure amount between the display region and the region where the contact hole is provided.