JP2014235885A - Display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a display device that has a partition of inverted tapering shape, the display device being able to reduce the film thickness of a second electrode (upper electrode).SOLUTION: A display device comprises: a substrate; a plurality of organic EL elements provided on a display area on the substrate; and a partition defining the area where the organic EL elements are provided, and also defining a contact hole provided outside the display area. Each of the organic EL elements includes: a first electrode; a second electrode provided with more space from the substrate than the first electrode; and one or more organic EL layers provided between the electrodes. The second electrode has a connection part extending over the partition from the display area to the contact hole. In the display area, the substrate-side end of the partition is formed such that the angle between a side of the end and the base of this end is obtuse. In the area where the contact hole is formed, the end is formed such that the angle between the side and the bottom is acute.

Description

  The present invention relates to a display device and a manufacturing method thereof.

  One display device uses an organic EL (Electro Luminescence) element as a light source of a pixel. For example, in a color display device, three types of organic EL elements are provided as pixel light sources. That is, (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 are provided on the substrate. .

  On the substrate, a partition wall that defines a region in which the organic EL element is provided is usually provided. As such a partition, for example, a lattice-shaped partition is provided. The three types of organic EL elements are arranged in alignment in the region surrounded by the partition walls.

  FIG. 10 is a cross-sectional view schematically showing a predetermined pixel. The partition walls are roughly classified into so-called forward tapered partition walls and reverse tapered partition walls. The forward-tapered partition wall is formed so that the angle formed between the side surface and the bottom surface of the partition wall is an acute angle. The reverse-tapered partition is formed so that the angle formed between the side surface of the partition and the bottom surface is an acute angle. FIG. 10 shows a reverse-tapered partition wall 51.

  Each organic EL element 52 is formed by sequentially laminating a first electrode 53, one or a plurality of organic EL layers 54 and 55, and a second electrode 56 in a region surrounded by a partition wall.

  The organic EL layers 54 and 55 are formed by a coating method, for example. Specifically, it is formed by applying an ink containing a material to be the organic EL layers 54 and 55 to a region surrounded by the partition walls 51 and solidifying it.

  The ink applied to the region surrounded by the partition wall 51 may be repelled on the surface of the first electrode 53 or the surface of the partition wall 51. Thus, when ink is repelled on the surface of the first electrode 53 or the partition wall 51, defects such as holes may occur in the organic EL layers 54 and 55.

  When the inversely tapered partition wall 51 is used, occurrence of such a problem can be suppressed. When the inversely tapered partition wall 51 is used, the portion where the partition wall 51 and the surface of the first electrode 53 are in contact with each other is configured to be narrower toward the distal end portion 57, so that the capillary phenomenon occurs at the distal end portion 57. Arise. This capillary phenomenon causes an effect that the ink spreads over the entire surface, thereby preventing the occurrence of defects in the organic EL layers 54 and 55 (see, for example, Patent Document 1).

JP 2007-227289 A

  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 provided 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 wall 51. Specifically, the second electrode 56 includes a connection portion 61 that extends on the partition wall from a display region where a plurality of organic EL elements are provided to a contact region outside the display region, and a contact provided in the contact region. It is connected to an external power source through the conductor 62 and the electrode wiring 63 provided on the substrate.

  FIG. 11 is a cross-sectional view schematically showing the contact region. The above-described partition wall 51 is formed so as to define not only a region where the organic EL element is provided, but also a contact hole provided outside the display region. Note that the partition wall 51 that defines the region where the organic EL element is provided and the partition wall 51 that defines the contact hole are collectively formed in the same process, for example, by a photolithography process. Further, the connection portion 61 extending on the partition wall 51 and the contact conductor 62 provided in the contact hole are collectively formed when the second electrode 56 is formed.

  As described above, when the connection portion 61 and the contact conductor 62 are formed in the same process as the second electrode 56, the connection portion 61 and the contact conductor 62 have the same film thickness as the second electrode 56. Therefore, when the second electrode 61 having a small film thickness is formed by vapor deposition or the like, there is a possibility that disconnection may occur in the contact region as shown in FIG.

  In order to prevent disconnection of the contact region, it is necessary to increase the thickness of the second electrode (that is, the thickness of the connection portion). When the thickness of the second electrode is increased as described above, there are problems that the time required for forming the electrode becomes longer and damage to the light emitting layer and the like during the electrode formation increases. In the display region, even if the second electrode having a small thickness is formed, the organic EL layers 54 and 55 are formed in the region surrounded by the partition wall, so that occurrence of disconnection can be avoided. .

  Accordingly, an object of the present invention is to provide a display device in which the thickness of the second electrode (upper electrode) can be reduced in a display device provided with an inversely tapered partition.

The present invention comprises a substrate;
A plurality of organic EL elements provided in a display region on the substrate;
A display device that defines a region in which the organic EL element is provided and a partition wall that defines a contact hole provided outside the display region;
The plurality of organic EL elements include a first electrode, a second electrode provided farther from the substrate than the first electrode, and one or more organic EL layers provided between the electrodes. Have
The second electrode has a connection portion extending on the partition wall from the display region to the contact hole,
The end of the partition on the substrate side is
In the display area, an angle formed between the side surface and the bottom surface is formed to be an obtuse angle,
In the region where the contact hole is formed, the present invention relates to a display device in which an angle formed between a side surface and a bottom surface thereof is an acute angle.

The present invention also relates to the display device, wherein an end of the partition opposite to the substrate side is formed so that an angle formed between a side surface and a bottom surface of the display region is an acute angle.
The present invention also relates to the display device, wherein the surface of the second electrode on the substrate side is formed so as to be separated from the substrate as it approaches the partition from the center of the organic EL element.

Moreover, this invention is a manufacturing method of the said display apparatus, Comprising:
A negative photoresist is applied on the substrate to form a partition forming film, and the partition forming film is exposed and developed with different exposure amounts in the display region and the region in which the contact hole is provided. The present invention relates to a method for manufacturing a display device, which includes a step of forming the partition wall.

  According to the present invention, it is possible to realize a display device capable of reducing the thickness of the second electrode (upper electrode) in a display device including an inversely tapered partition.

3 is a plan view of the display device 1. FIG. 3 is a plan view schematically showing a part of a display region 30. FIG. 4 is a cross-sectional view showing a region where one organic EL element 4 is provided in the display region 30. FIG. FIG. 6 is a cross-sectional view when the contact region 31 is cut along a plane perpendicular to the column direction Y. It is sectional drawing of the display apparatus in the middle of formation shown in order to demonstrate the manufacturing method of a display apparatus. It is sectional drawing of the display apparatus in the middle of formation shown in order to demonstrate the manufacturing method of a display apparatus. It is sectional drawing of the display apparatus in the middle of formation shown in order to demonstrate the manufacturing method of a display apparatus. It is sectional drawing of the display apparatus in the middle of formation shown in order to demonstrate the manufacturing method of a display apparatus. 3 is a plan view of the display device 1. FIG. It is sectional drawing which shows a predetermined pixel typically. It is sectional drawing which shows a contact region typically. It is sectional drawing which shows a contact region typically.

  The display device of the present invention defines a substrate, a plurality of organic EL elements provided in a display region on the substrate, a region in which the organic EL element is provided, and a contact hole provided outside the display region. The plurality of organic EL elements include a first electrode, a second electrode provided farther from the substrate than the first electrode, and a gap between the electrodes. One or a plurality of organic EL layers provided, and the second electrode has a connecting portion extending on the partition from the display region to the contact hole, and an end of the partition on the substrate side In the display region, the angle formed between the side surface and the bottom surface is formed as an obtuse angle, and in the region where the contact hole is formed, the angle formed between the side surface and the bottom surface is formed into an acute angle. Formed There is a display device.

  There are mainly two types of display devices: an active matrix drive type device and a passive matrix drive type device. Although the present invention can be applied to both types of display devices, in this embodiment, a display device applied to an active matrix drive type display device will be described as an example.

<Configuration of display device>
First, the configuration of the display device will be described. FIG. 1 is a plan view of the display device 1. The display device 1 mainly defines a substrate 2, a plurality of organic EL elements 4 provided in the display region 30 on the substrate 1, and a region in which the organic EL elements 4 are provided, and contacts provided outside the display region. And a partition wall 3 that defines a hole.

  A display area 30 and a contact area 31 are set on the substrate 2.

  A plurality of organic EL elements 4 are provided in the display area 30. In the present embodiment, the partition wall 3 is generally formed on the entire surface of the substrate 2 except for the display region 30 and the contact region 31. In the present embodiment, the partition walls 3 are provided in a lattice pattern in the display area 30. As another embodiment, for example, the partition walls 3 are provided in stripes in the display region 30.

  FIG. 2 is a plan view schematically showing a part of the display area 30. In FIG. 2, the region where the partition wall 3 is provided is hatched. As shown in FIG. 2, in this embodiment, the partition walls 3 are provided in a lattice shape. The organic EL elements 4 are provided in regions surrounded by the partition walls 3.

  FIG. 3 is a cross-sectional view showing a region where one organic EL element 4 is provided in the display region 30.

  A plurality of recesses 5 defined by the partition walls 3 and the substrate 2 are set on the substrate 2. Each organic EL element 4 is provided in the recess 5.

  The partition walls 3 of the present embodiment are provided in a lattice shape. Therefore, when viewed from one side in the thickness direction Z of the substrate 2 (hereinafter sometimes referred to as “in plan view”), the plurality of recesses 5 are arranged in a matrix. That is, the recesses 5 are provided with a predetermined interval in the row direction X and aligned in the column direction Y with a predetermined interval. The shape of each recess 5 in plan view is not particularly limited. For example, the recessed part 5 is formed in a substantially rectangular shape and a substantially elliptical shape in plan view. In the present embodiment, a substantially rectangular recess 5 is provided in plan view. In the present specification, the row direction X and the column direction Y mean directions perpendicular to the thickness direction Z of the substrate and perpendicular to each other.

  In the case where a stripe-shaped partition is provided as another embodiment, the partition is configured by, for example, a plurality of partition members extending in the row direction X being arranged at predetermined intervals in the column direction Y. In this embodiment, a stripe-shaped recess is defined by the stripe-shaped partition wall and the substrate.

  In the display region 30, the end 3a of the partition wall 3 on the substrate 2 side is formed such that an angle θ1 formed between the side surface and the bottom surface thereof is an obtuse angle. For example, when the partition 3 extending in the column direction Y is cut along a plane perpendicular to the extending direction (column direction Y), the cross-sectional shape is formed so as to become wider as the distance from the substrate 2 increases. .

  In the display region 30, the angle θ1 formed between the side surface of the partition wall 3 and the surface of the substrate, that is, the inclination angle θ1 of the side surface of the partition wall is about 95 ° to 170 °, preferably 100 ° to 120 °. The partition wall 3 having a side wall inclination angle θ1 of 0 ° to 90 ° is referred to as a so-called forward-tapered partition wall, and the partition wall 3 having a side wall inclination angle θ1 of 90 ° to 180 ° is a so-called reverse taper shape. Is called a partition wall. That is, in the present embodiment, the display region 30 is provided with the inversely tapered partition wall 3.

  Further, the end 3b of the partition 3 on the side opposite to the substrate 2 side is preferably formed so that the angle formed between the side surface and the bottom surface of the display region 30 is an acute angle. That is, the partition wall 3 is not formed in a consistently reverse tapered shape from the end 3a on the substrate 2 side to the end 3b on the opposite side to the substrate 2 side, but the end 3a on the substrate 2 side is reversed. It is preferably formed in a tapered shape, and is formed in a forward tapered shape at the end portion 3b opposite to the substrate 2 side. By making such a shape, it is possible to further prevent the second electrode from being disconnected in the boundary region between the partition wall 3 and the organic EL layer.

  The organic EL element 4 is provided in a partition (that is, the recess 5) defined by the partition 3. When the grid-like partition 3 is provided as in the present embodiment, each organic EL element 4 is provided in each recess 5. That is, the organic EL elements 4 are arranged in a matrix like the recesses 5 and are arranged on the substrate 2 with a predetermined interval in the row direction X and in a row with a predetermined interval in the column direction Y. It has been.

  In another embodiment, when stripe-shaped partition walls are provided, the organic EL elements 4 are arranged at predetermined intervals in the row direction X in the respective recesses extending in the row direction X.

In the present embodiment, three types of organic EL elements 4 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 are provided. These three types of organic EL elements 4R, 4G, and 4B are arranged in alignment, for example, by repeatedly arranging the following rows (I), (II), and (III) in this order in the column direction Y. (See FIG. 2).
(I) Rows in which the red organic EL elements 4R are arranged at predetermined intervals in the row direction X.
(II) Rows in which the green organic EL elements 4G are arranged at predetermined intervals in the row direction X.
(III) A row in which the blue organic EL elements 4B are arranged at predetermined intervals in the row direction X.

  As another embodiment, in addition to the above three types of organic EL elements, for example, an organic EL element that emits white light may be further provided. In addition, a monochrome display device may be realized by providing only one type of organic EL element.

  The organic EL element 4 includes a first electrode 6, a second electrode 10 provided farther from the substrate than the first electrode, and one or a plurality of organic EL layers provided between the electrodes. Have. In the present specification, one 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 includes at least one light emitting layer as an organic EL layer. In addition to the one light emitting layer, the organic EL element 4 may further include an organic EL layer different from the light emitting layer as necessary. For example, a hole injection layer, a hole transport layer, an electron block layer, an electron transport layer, an electron injection layer, and the like are provided as an organic EL layer between the first electrode 6 and the second electrode 10. 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 first electrode 6 and a second electrode 10 as a pair of electrodes including an anode and a cathode. One of the first electrode 6 and the second electrode 10 is provided as an anode, and the other electrode is provided as a cathode.

  In the present embodiment, as an example, the first electrode 6 functioning as an anode, the first organic EL layer 7 functioning as a hole injection layer, the second organic EL layer 9 functioning as a light emitting layer, and the first functioning as a cathode. The organic EL element 4 configured by stacking the two electrodes 10 on the substrate 2 in this order will be described.

  In the present embodiment, three types of organic EL elements are provided, but these have different configurations of the second organic EL layer (light emitting layer in the present embodiment) 9. 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 emits blue light. A blue light emitting layer 9B is provided.

  In the present embodiment, the first electrode 6 is provided for each organic EL element 4. That is, the same number of first electrodes 6 as the organic EL elements 4 are provided on the substrate 2. The first electrodes 6 are provided corresponding to the arrangement of the organic EL elements 4, and are arranged in a matrix like the organic EL elements 4. In addition, although the partition 3 of this embodiment is mainly formed in a lattice shape in a region excluding the first electrode 6, it is further formed so as to cover the periphery of the first electrode 6 (see FIG. 3). .

  The first organic EL layer 7 corresponding to the hole injection layer is provided on the first electrode 6 in the recess 5. The first organic EL layer 7 is provided with a different material or film thickness for each type of organic EL element, if necessary. In addition, from a viewpoint of the simplicity of the formation process of the 1st organic EL layer 7, you may form all the 1st organic EL layers 7 with the same material and the same film thickness.

  The second organic EL layer 9 functioning as a light emitting layer is provided on the first organic EL layer 7 in the recess 5. As described above, the light emitting layer is provided according to the type of the organic EL element. Therefore, the red light emitting layer 9R is provided in the concave portion 5 where the red organic EL element 4R is provided, the green light emitting layer 9G is provided in the concave portion 5 where the green organic EL element 4G is provided, and the blue light emitting layer 9B is provided by the blue organic EL element 4B. It is provided in the provided recess 5.

  The second electrode 10 is formed on the entire surface in the display region where the organic EL element 4 is provided. That is, the second electrode 10 is formed not only on the second organic EL layer 9 but also on the partition 3 and continuously formed over a plurality of organic EL elements.

  The surface of the second electrode 10 on the substrate 2 side is preferably formed so as to be separated from the substrate 2 as it approaches the partition wall 3 from the center of the organic EL element 4. In other words, the surface formed by the organic EL layer 9 and the partition 3 in contact with the second electrode 10 may be formed so as to be separated from the substrate 2 as it approaches the partition 3 from the center of the organic EL element 4. preferable. Since the surface constituted by the organic EL layer 9 and the partition 3 in contact with the second electrode 10 is configured in this manner, the second electrode 10 is disconnected at the boundary region between the organic EL layer 9 and the partition 3. Can be prevented more.

  In the above embodiment, the partition 3 is provided in contact with the substrate 2 so as to cover the peripheral edge of the first electrode 6. However, as another embodiment, further insulation is provided between the partition 3 and the substrate 2. A film may be provided. The insulating film is formed, for example, in a lattice shape like the partition wall and covers the peripheral edge of the first electrode 6. Such an insulating film is preferably formed of a material that is more lyophilic than the partition 3.

  In the present embodiment, the contact region 31 is provided so as to extend in the column direction Y at a position separated in one of the display regions 30 in the row direction X (leftward in FIG. 1). In this specification, the contact region means a region where a contact hole and a contact conductor are provided. Further, in the present embodiment, the contact region 31 is provided to extend in the column direction Y at a position separated from the other of the display regions 30 in the row direction X (rightward in FIG. 1). FIG. 4 is a cross-sectional view of the contact region 31 taken along a plane perpendicular to the column direction Y.

  In the region where the contact hole is formed, the end portion of the partition wall on the substrate side (lower end portion in FIG. 4) is formed such that the angle θ2 formed between the side surface and the bottom surface is an acute angle. That is, in the present embodiment, the forward tapered partition 3 is provided in the region where the contact hole is formed. θ2 is about 5 ° to 85 °, preferably 20 ° to 60 °.

  In the contact region 31, a through hole is formed in the partition 3 in a region corresponding to the contact hole. This through hole is formed to extend in the column direction Y in this 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. Further, a conductor film extending integrally from the second electrode 10 is formed on the partition wall 3 and in the contact hole. In this conductor film, a portion extending on the partition wall from the display region to the contact hole is referred to as a connection portion 23, and a portion formed in the contact hole is referred to as a contact conductor 22.

  In this way, the second electrode 10, the connection portion 23, and the contact conductor 22 are integrally formed, and the contact conductor 22 is further connected to the electrode wiring 20. 20 connects the second electrode to an external power source.

  Hereinafter, a method for manufacturing a display device will be described with reference to FIGS. 5 and 6 show a region (display region) corresponding to FIG. 3, and FIGS. 7 and 8 show a region (contact region) corresponding to FIG.

(Process 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 this step, the substrate 2 on which the first electrode 6 and the electrode wiring 20 are formed may be prepared by obtaining from the market a substrate on which the first electrode 6 and the electrode wiring 20 are formed.

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

  First, a plurality of first electrodes 6 are formed in a matrix on the substrate 2, and electrode wirings 20 are formed at predetermined portions. The first electrode 6 is formed, for example, by forming a conductive thin film on one surface of the substrate 2 and patterning it in a matrix by a photolithography method. In addition, for example, a mask having an opening formed in a predetermined portion is disposed on the substrate 2, and the first electrode 6 is formed by selectively depositing a conductive material on the predetermined portion on the substrate 2 through the mask. A pattern may be formed. Further, the electrode wiring 20 is formed together with the first electrode 6 in the same process as the first electrode 6, for example, in the same process as the first electrode 6. The materials of the first electrode 6 and the electrode wiring 20 will be described later (see FIGS. 5A and 7A).

(Step of forming partition walls)
In this step, a negative photoresist is applied onto the substrate to form a partition forming film, and the partition forming film is exposed with different exposure amounts in the display region and the region in which the contact hole is provided. The partition is formed by development. The region where the contact hole is provided means a region including a region where the contact conductor is provided and a peripheral portion of this region.

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

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

  After the ink containing the photosensitive resin is applied and formed on the substrate, it is usually pre-baked. For example, pre-baking is performed by heating the substrate at a temperature of 80 ° C. to 110 ° C. for 60 seconds to 180 seconds to remove the solvent.

  Next, a photomask 21 that shields light of a predetermined pattern is disposed on the substrate 2, and the partition wall forming film 8 is exposed through the photomask 21. The photosensitive resin includes a positive type resin and a negative type resin. In this step, a negative type photosensitive resin is used. In the case where a negative photosensitive resin is used, light is irradiated mainly on a portion of the partition wall forming film 8 where the partition wall 3 is to be formed.

  In the present embodiment, the partition forming film 8 is exposed with different exposure amounts in the region where the organic EL element is provided and the region where the contact hole is provided. By varying the exposure amount in this manner, the inversely tapered partition walls 3 can be formed in the display region 30, and the forward tapered partition walls 3 can be formed in the contact region 31.

  Specifically, when a proximity exposure machine that cannot perform division exposure is used, the exposure area is divided using two photomasks, and exposure is performed twice. Thereby, the exposure amount can be varied.

  When a stepper capable of division exposure is used, the exposure amount can be varied by changing the exposure amount according to the exposure area using a single photomask.

  In this embodiment, a proximity exposure machine that cannot perform divided exposure is used. Specifically, the exposure area is divided into a first exposure area and a second exposure area, and exposure is performed in two steps using two types of photomasks 21 corresponding to the respective exposure areas.

FIG. 9 is a plan view of the display device 1 for explaining the exposure area. In the present embodiment, the first exposure region corresponds to the display region 30 and the peripheral portion 32 of the display region 30. In FIG. 9, the peripheral edge 32 of the display area 30 is hatched. The second exposure area corresponds to an area excluding the display area 30. That is, the second exposure region includes a contact region. In this case, the first exposure area and the second exposure area overlap at the peripheral edge 32 of the display area 30. Therefore, the peripheral edge 32 of the display area 30 is exposed twice.
First, the first exposure area is exposed. As shown in FIG. 5C, the first photomask 21a is arranged on the substrate 2, and light is irradiated through the photomask 21a, so that the main portion of the partition wall formation film 8 in the first exposure region. Then, light is irradiated to the portion where the partition wall 3 is to be formed with the first exposure amount. In this step, the contact region 31 is shielded from light by the first photomask 21a. In FIG. 5C, the light applied to the partition wall forming film 8 is schematically indicated by an arrow symbol.

  Next, the second exposure area is exposed. As shown in FIG. 7C, a second photomask 21b is arranged on the substrate, and light is irradiated through the photomask 21b, so that mainly in the partition forming film 8 in the second exposure region. Light is irradiated to the portion where the partition wall 3 is to be formed, that is, the region excluding the contact region with the second exposure amount. In this step, the contact region 31 and the display region 30 are shielded from light by the second photomask 21b. In FIG. 7C, the light applied to the partition wall forming film 8 is schematically indicated by an arrow symbol.

  Note that a light amount obtained by integrating the first exposure amount and the second exposure amount is irradiated on the region where the first exposure region and the second exposure region overlap.

In general, in the case of a negative photosensitive resin, as the exposure amount is increased, the inclination angles θ1 and θ2 of the side walls of the partition wall tend to be smaller. Therefore, the first exposure amount is set so that the exposure amount is smaller than the second exposure amount. First exposure amount is set according to the inclination angle .theta.1, for example, ^{20mJ / m 2 ~60mJ / m 2} , more preferably ^{20mJ / m 2 ~40mJ / m 2} .

Second exposure amount is set according to the inclination angle .theta.2, for example, ^{60mJ / m 2 ~200mJ / m 2} , more preferably ^{80mJ / m 2 ~100mJ / m 2} .

  The inclination angles θ1 and θ2 can also be adjusted by adjusting the development time. In general, in the case of a negative photosensitive resin, the inclination angles θ1 and θ2 tend to increase as the development time increases. The inclination angles θ1 and θ2 can also be adjusted by adjusting the distance between the photomask and the substrate. In general, in the case of a negative photosensitive resin, the inclination angles θ1 and θ2 tend to approach 90 ° as the distance between the photomask and the substrate is shortened.

  Further, the inclination angles θ1 and θ2 may depend on the film thickness of the partition wall forming film 8. Therefore, the film thickness of the partition wall forming film 8 is preferably 0.5 μm to 1 μm, and more preferably 0.6 μm to 0.7 μm.

  Next, development is performed. As a result, the barrier ribs 3 are patterned (see FIGS. 6A and 8A). After development, post-bake is performed as necessary. For example, post-baking is performed by heating the substrate at a temperature of 200 ° C. to 230 ° C. for 15 to 60 minutes to cure the partition walls 3.

  By forming the partition walls as described above, the inversely tapered partition walls 3 are formed in the display region 30, and the forward tapered partition walls 3 are formed in the contact region 31.

  In general, a photosensitive resin composition used for forming the partition walls is a mixture of a binder resin, a crosslinking material, a photoreaction initiator, a solvent, an ultraviolet absorber, and other additives.

  The binder resin is polymerized in advance. Examples thereof include a non-polymerizable binder resin that does not have self-polymerizability and a polymerizable binder resin into which a substituent having polymerizability is introduced. The binder resin has a weight average molecular weight in the range of 5,000 to 400,000 determined by gel permeation chromatography (GPC) using polystyrene as a standard.

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

  Examples of the cross-linking material include compounds that can be polymerized by active radicals, acids, and the like generated from the photopolymerization initiator by irradiation with light, and examples thereof include compounds having a polymerizable carbon-carbon unsaturated bond. The cross-linking material may be a monofunctional compound having one polymerizable carbon-carbon unsaturated bond in the molecule, or bifunctional or trifunctional having two or more polymerizable carbon-carbon unsaturated bonds. The above polyfunctional compounds may be used. In the ink containing the photosensitive resin, the crosslinking material is usually 0.1 parts by mass or more and 70 parts by mass or less when the total amount of the binder resin and the crosslinking material 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 material is 100 parts by mass.

  Specifically, a negative photosensitive resin composition (ZPN2464 manufactured by Nippon Zeon Co., Ltd.) can be used.

  Furthermore, a liquid repellent may be mixed with the photosensitive resin composition to prepare a photosensitive resin composition containing the liquid repellent. As the liquid repellent, for example, Daikin liquid repellent Optoace (registered commercial method) HP series can be used. The ratio of the solid content concentration of the liquid repellent to the total solid content of the photosensitive resin composition excluding the liquid repellent {(total solid content of the photosensitive resin composition excluding the liquid repellent / liquid repellent) × 100} is 0.1% to 1 0.0% (weight) is preferred.

  Light (irradiation light) irradiated to the present photosensitive resin composition is absorbed by an ultraviolet absorber or the like, and therefore becomes weaker as it is separated from the surface side. Therefore, the photosensitive resin composition is characterized in that the light irradiation side (surface side) is more easily cured and is harder to be cured as it is separated from the surface side. Therefore, when the exposure amount is small, the vicinity of the bottom surface where the irradiated light is difficult to reach is hard to be cured, and when exposed to the developer, the shape of the partition wall end becomes an inversely tapered shape. On the other hand, when light is irradiated with an exposure amount sufficient to cure the photosensitive resin composition in the thickness direction, a forward tapered shape can be obtained.

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

  The shape and arrangement of the partition walls 3 are appropriately set according to the specifications of the display device such as the number of pixels and resolution, the ease of manufacturing, and the like. For example, the width of the partition 3 in the row direction X or the column direction Y in the display region 30 is about 5 μm to 50 μm, the height of the partition 3 is about 0.3 μm to 5 μm, and is adjacent to the row direction X or the column direction Y. The interval between the partition walls 3, that is, the width of the recess 5 in the row direction X or the column direction Y is about 10 μm to 200 μm. The width of the first electrode 6 in the row direction X or the column direction Y is about 10 μm to 200 μm, respectively.

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

(Process of forming organic EL layer)
In this step, an organic EL layer is formed (see FIG. 6B). In this embodiment, at least one organic EL layer among the 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.

  First, an ink 22 containing a material that becomes the first organic EL layer 7 is supplied to a region (recessed portion 5) surrounded by the partition walls 3. The ink is appropriately supplied by an optimum method in consideration of the shape of the partition wall 3, the simplicity of the film forming process, the film forming property, and the like. The ink is supplied by, for example, an inkjet printing method, a nozzle coating method, a relief printing method, an intaglio printing method, or the like.

  Next, the first organic EL layer 7 is formed by solidifying the supplied ink. The ink can be solidified by, for example, natural drying, heat drying, or vacuum drying. Also, when the ink contains a material that polymerizes by applying energy, after supplying the ink, the material constituting the organic EL layer is polymerized by heating the thin film or irradiating the thin film with light. Also good. Thus, by polymerizing the material which comprises an organic EL layer, an organic EL layer can be hardly soluble with respect to the ink used when forming an organic EL layer further on this organic EL layer.

  Next, a second organic EL layer 9 that functions 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 ink containing materials for forming the red light emitting layer 9R, the green light emitting layer 9G, and the blue light emitting layer 9B are respectively supplied to the regions surrounded by the partition walls 3, and further solidified to thereby provide each light emitting layer 9R, 9G and 9B can be formed.

  By forming the organic EL layer by the coating method as described above, a reverse-tapered partition wall is provided, so that the ink supplied to the region surrounded by the partition wall 3 (recessed portion 5) is first caused by capillary action. The electrode 6 and the partition wall 3 are filled so as to be sucked into the tapered portion 7a to which the electrode 6 and the partition wall 3 are connected. While the ink solvent evaporates while maintaining this state, an organic EL layer is also formed at a site where the first electrode 6 and the partition wall 3 are connected. Thereby, an organic EL layer having a uniform film thickness can be obtained.

  The tapered portion 7 a where the first electrode 6 and the partition wall 3 are connected is filled with the organic EL layer 7, so that the organic EL layer 9 and the partition wall 3 are in contact with the second electrode 10. The surface is formed so as to be separated from the substrate 2 as it approaches the partition wall 3 from the central portion of the organic EL element 4.

(Step of forming second electrode and the like)
Next, a conductive thin film is formed in all regions (at least the display region 30 and the contact region 31 and the region between the display region 30 and the contact region 31) except for a predetermined region of the substrate 2. As a result, the second electrode 10, the connecting portion 23, and the contact conductor 22 are formed.

  In this embodiment, since the partition wall 3 is formed in a forward tapered shape in the contact region 31, even if the connection portion 23 and the contact conductor 22 are thin, they are disconnected at the end of the partition wall 3. Can be prevented.

  In the display region 30, the partition wall 3 is formed in an inversely tapered shape. However, since the end portion on the substrate 2 side of the region surrounded by the partition wall 3 is filled with the organic EL layers 7 and 9, the second electrode Even when the film thickness of 10 is thin, it is possible to prevent the second electrode 10 from being disconnected at the end of the partition wall 3.

  As described above, the partition wall 3 is formed in a forward tapered shape in the contact region 31, and the partition wall 3 is formed in a reverse tapered shape in the display region 30, whereby the film thicknesses of the second electrode 10, the connection portion 23, and the contact conductor 22 are formed. The time required to form these can be shortened compared to the prior art.

  The film thicknesses of the second electrode 10, the connection part 23, and the contact conductor 22 are set in consideration of the required electric resistance and film formation time, but are 10 nm to 1 μm, preferably 50 nm to 500 nm, preferably 100 nm. More preferably, ˜200 nm.

  As described above, the surface of the second electrode 10 on the substrate 2 side is formed so as to be separated from the substrate 2 as it approaches the partition wall 3 from the center of the organic EL element 4. In other words, the surface formed by the organic EL layer 9 and the partition 3 in contact with the second electrode 10 is formed so as to be separated from the substrate 2 as it approaches the partition 3 from the center of the organic EL element 4. Since the surface constituted by the organic EL layer 9 and the partition 3 in contact with the second electrode 10 is configured in this manner, the second electrode 10 is disconnected at the boundary region between the organic EL layer 9 and the partition 3. Can be prevented.

<Configuration of organic EL element>
Below, the structure of an organic EL element is demonstrated in detail. The organic EL element has at least one light emitting layer as an organic EL layer. As described above, for example, a hole injection layer, a hole transport layer, an electron block layer, a hole block layer, an electron transport can be used as the organic EL layer. A layer, an electron injection layer, and the like.

An example of a layer structure that can be taken by the organic EL element 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 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 / light emitting layer / electron injection layer / cathode i) Anode / light emitting layer / electron transport layer / electron injection Layer / Cathode (Here, the symbol “/” indicates that the layers sandwiching the symbol “/” are adjacently stacked. The same applies hereinafter.)

  In the above-described embodiment, the organic EL element in which the first electrode functioning as the anode is disposed closer to the substrate than the second electrode has been described. However, the present invention is the first electrode functioning as the cathode. However, the present invention can also be applied to an organic EL element that is disposed closer to the substrate with respect to the second electrode. In addition, in the above-described embodiments a) to i), the organic EL element can take a form in which the cathode is laminated sequentially from the anode and the cathode is laminated last, or a cathode is laminated sequentially from the cathode and the anode is laminated last.

<Board>
As the substrate, a substrate that is not chemically changed in the process of manufacturing the organic EL element is suitably used. For example, a glass substrate, a plastic substrate, a polymer film substrate, a silicon substrate, and a laminate of these are used. .

<Anode>
In the case of an organic EL element having a configuration in which light emitted from the light emitting layer is emitted to the outside through the anode, an electrode exhibiting optical transparency is used for the anode. As the electrode exhibiting light transmittance, a thin film of metal oxide, metal sulfide, metal or the like can be used, and an electrode having high electrical conductivity and light transmittance is preferably used. Specifically, a thin film made of indium oxide, zinc oxide, tin oxide, ITO, indium zinc oxide (abbreviated as IZO), gold, platinum, silver, copper, or the like is used. Among these, ITO, IZO Or a thin film made of tin oxide is preferably used. Examples of a method for producing the anode include a vacuum deposition method, a sputtering method, an ion plating method, and a plating method. Further, an organic transparent conductive film such as polyaniline or a derivative thereof, polythiophene or a derivative thereof may be used as the anode.

<Cathode>
A material for the cathode is preferably a material having a low work function, easy electron injection into the light emitting layer, and high electrical conductivity. Further, in the organic EL element configured to extract light from the anode side, the material of the cathode is preferably a material having high reflectivity with respect to visible light in order to reflect the light emitted from the light emitting layer to the anode side by the cathode. As the cathode, for example, an alkali metal, an alkaline earth metal, a transition metal, a group 13 metal of the periodic table, or the like can be used. Examples of cathode materials include lithium, sodium, potassium, rubidium, cesium, beryllium, magnesium, calcium, strontium, barium, aluminum, scandium, vanadium, zinc, yttrium, indium, cerium, samarium, europium, terbium, ytterbium, and the like. A metal, two or more alloys of the metals, one or more of the metals, and one or more of gold, silver, platinum, copper, manganese, titanium, cobalt, nickel, tungsten, tin An alloy, graphite, or a graphite intercalation compound is used. Examples of alloys include magnesium-silver alloys, magnesium-indium alloys, magnesium-aluminum alloys, indium-silver alloys, lithium-aluminum alloys, lithium-magnesium alloys, lithium-indium alloys, calcium-aluminum alloys, and the like. it can. As the cathode, a transparent conductive electrode made of a conductive metal oxide or a conductive organic material 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 substance include polyaniline or a derivative thereof, polythiophene or a derivative thereof, and the like. The cathode may be composed of a laminate in which two or more layers are laminated. The electron injection layer may be used as a cathode.

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

  The film thickness of the anode or cathode is appropriately set in consideration of the required characteristics and the simplicity of the film forming process, and is, for example, 10 nm to 10 μm, preferably 20 nm to 1 μm, and more preferably 50 nm to 500 nm. . Of the anode and the cathode, the electrode provided as the second electrode is set in consideration of the required electric resistance and film formation time as described above, but is 10 nm to 1 μm, and 50 nm. ˜500 nm is preferable, and 100 nm to 200 nm is more preferable.

  For the electrode wiring 20, the connection portion 23, and the contact conductor 22, the materials exemplified as the cathode and anode materials can be used. Furthermore, it is preferable that the connection part 23 and the contact conductor 22 are formed in the same process using the same material as the second electrode. The electrode wiring 20 does not have to be formed using the same material as the first or second electrode, but is preferably formed so that the electric resistance is smaller than that of the first or second electrode. It is preferable to form so that contact resistance with 22 becomes small.

<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, Examples thereof include polyaniline and polythiophene derivatives.

  Examples of the method for forming the hole injection layer include film formation from a solution containing a hole injection material. For example, a hole injection layer can be formed by coating a film containing a hole injection material by a predetermined coating method and solidifying the solution.

  The film thickness of the hole injection layer is appropriately set in consideration of required characteristics and process simplicity, and 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>
As the hole transport material constituting the hole transport layer, polyvinylcarbazole or a derivative thereof, polysilane or a derivative thereof, a polysiloxane derivative having an aromatic amine in a side chain or a main chain, a pyrazoline derivative, an arylamine derivative, a stilbene derivative, Triphenyldiamine derivative, polyaniline or derivative thereof, polythiophene or derivative thereof, polyarylamine or derivative thereof, polypyrrole or derivative thereof, poly (p-phenylene vinylene) or derivative thereof, or poly (2,5-thienylene vinylene) or Examples thereof include derivatives thereof.

  The film thickness of the hole transport layer is set in consideration of the required characteristics and the simplicity of the film forming process, and is, for example, 1 nm to 1 μm, preferably 2 nm to 500 nm, more preferably 5 nm to 200 nm. .

<Light emitting layer>
The light emitting layer is usually formed of an organic substance that mainly emits fluorescence and / or phosphorescence, or an organic substance and a dopant that assists the organic substance. The dopant is added, for example, in order to improve the luminous efficiency and change the emission wavelength. In addition, the organic substance which comprises a light emitting layer may be a low molecular compound or a high molecular compound, and when forming a light emitting layer by the apply | coating method, it is preferable that a light emitting layer contains a high molecular compound. The number average molecular weight in terms of polystyrene 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 dye materials, metal complex materials, polymer materials, and dopant materials.

(Dye material)
Examples of dye-based materials include cyclopentamine derivatives, tetraphenylbutadiene derivative compounds, triphenylamine derivatives, oxadiazole derivatives, pyrazoloquinoline derivatives, distyrylbenzene derivatives, distyrylarylene derivatives, pyrrole derivatives, thiophene ring compounds. Pyridine ring compounds, perinone derivatives, perylene derivatives, oligothiophene derivatives, oxadiazole dimers, pyrazoline dimers, quinacridone derivatives, coumarin derivatives, and the like.

(Metal complex materials)
Examples of the metal complex material include rare earth metals such as Tb, Eu, and Dy, or Al, Zn, Be, Ir, Pt, etc. as a central metal, and oxadiazole, thiadiazole, phenylpyridine, phenylbenzimidazole, quinoline. Examples include metal complexes having a structure as a ligand, such as iridium complexes, platinum complexes, etc., metal complexes having light emission from a triplet excited state, aluminum quinolinol complexes, benzoquinolinol beryllium complexes, benzoxazolyl zinc A complex, a benzothiazole zinc complex, an azomethylzinc complex, a porphyrin zinc complex, a phenanthroline europium complex, and the like can be given.

(Polymer material)
As polymer materials, polyparaphenylene vinylene derivatives, polythiophene derivatives, polyparaphenylene derivatives, polysilane derivatives, polyacetylene derivatives, polyfluorene derivatives, polyvinyl carbazole derivatives, the above dye materials and metal complex light emitting materials are polymerized. The thing etc. can be mentioned.

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

<Electron transport layer>
As the electron transport material constituting the electron transport layer, known materials can be used, such as oxadiazole derivatives, anthraquinodimethane or derivatives thereof, benzoquinone or derivatives thereof, naphthoquinone or derivatives thereof, anthraquinones or derivatives thereof, tetracyanoanthra. Quinodimethane or derivatives thereof, fluorenone derivatives, diphenyldicyanoethylene or derivatives thereof, diphenoquinone derivatives, or metal complexes of 8-hydroxyquinoline or derivatives thereof, polyquinoline or derivatives thereof, polyquinoxaline or derivatives thereof, polyfluorene or derivatives thereof, etc. Can be mentioned.

  The film thickness of the electron transport layer is appropriately set in consideration of the required characteristics and the simplicity of the film forming process, and is, for example, 1 nm to 1 μm, preferably 2 nm to 500 nm, more preferably 5 nm to 200 nm. .

<Electron injection layer>
As a material constituting the electron injection layer, an optimal material is appropriately selected according to the type of the light emitting layer, and an alloy containing one or more of alkali metals, alkaline earth metals, alkali metals and alkaline earth metals, Examples include alkali metal or alkaline earth metal oxides, halides, carbonates, and mixtures of these substances. Examples of alkali metals, 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, rubidium fluoride, cesium oxide, cesium fluoride, lithium carbonate, and the like. Examples of alkaline earth metals, alkaline earth metal oxides, halides and carbonates include magnesium, calcium, barium, strontium, magnesium oxide, magnesium fluoride, calcium oxide, calcium fluoride, barium oxide, Examples thereof include barium fluoride, strontium oxide, strontium fluoride, and magnesium carbonate. An electron injection layer may be comprised by the laminated body which laminated | stacked two or more layers, for example, LiF / Ca etc. can be mentioned.

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

  Each organic EL layer described above can be formed by, for example, a coating method such as a nozzle printing method, an ink jet printing method, a relief printing method, an intaglio printing method, a vacuum deposition method, a sputtering method, or a CVD method. When there are a plurality of organic EL layers, at least one organic EL layer is formed by a coating method.

  In the coating method, an ink containing an organic EL material to be each organic EL layer is applied and formed into an organic EL layer by further solidifying the ink. For example, chloro solvents such as chloroform, methylene chloride, dichloroethane, ether solvents such as tetrahydrofuran, aromatic hydrocarbon solvents such as toluene and xylene, ketone solvents such as acetone and methyl ethyl ketone, ethyl acetate, butyl acetate, and ethyl cellosolve An ester solvent such as acetate and water are used.

Example 1
First, a TFT substrate in which a first electrode (anode) made of an ITO thin film and electrode wirings were previously patterned was prepared (see FIGS. 5A and 7A).

  Next, the negative type photosensitive resin solution (ZPN2464 manufactured by Nippon Zeon Co., Ltd.) is mixed with the liquid repellent 2 (Daikin liquid repellent Opt-Ace (registered commercial method) HP series) to prepare the photosensitive resin solution containing the liquid repellent material. did. The solid content concentration ratio of the liquid repellent to the photosensitive resin was 0.2% (weight). Next, a photosensitive resin solution containing a liquid repellent material is applied and formed on the surface of the prepared TFT substrate by a spin coater, and further prebaked by heating on a hot plate at 110 ° C. for 90 seconds to remove the solvent. It evaporated (refer FIG. 5B and FIG. 7B).

Next, a photomask A and a photomask B for proximity exposure machine were prepared. Using the photomask A, the first exposure region (the display region 30 and the peripheral portion 32 of the display region 30) was exposed at an exposure amount of 40 mJ / cm ² (see FIGS. 5C and 9). Then, the 2nd exposure area | region (area | region except the display area 30) was exposed at 80 mJ / cm < ² > using the photomask B. FIG. (See FIGS. 7C and 9). Specifically, the area other than the contact area was exposed in the second exposure area. Thereafter, post-exposure baking (PEB) was performed at 110 ° C. for 60 seconds. Subsequently, development was carried out with a developer (SD-1 (TMAH 2.38 wt%) manufactured by Tokuyama Corporation) for 50 seconds to remove the unexposed photosensitive resin. Further, the resin was cured by heating at 230 ° C. for 30 minutes as a post-bake. Thereby, a reverse-tapered partition wall was formed in the display region, and a forward-tapered partition wall was formed outside the display region (including the cathode contact region) (see FIGS. 6A and 8A).

The partition wall thickness was 0.7 μm. As described above, the inclination angles θ1 and θ2 on the side walls of the partition wall may depend on the film thickness. When the film thickness is 0.7 μm as in this example, an inversely tapered shape is obtained at 40 mJ / cm ² or less. At 80 mJ / cm ² or more, a forward-tapered partition wall could be formed. In the display region 30, the angle θ1 formed between the side surface of the partition wall 3 and the surface of the substrate was 150 °. In the region where the contact hole is formed, the angle θ2 formed between the side surface of the partition wall 3 and the surface of the substrate was 25 °.

  The contact angle between the top surface of the partition wall and anisole was 50 °. The contact angle between the surface of the first electrode (ITO thin film) and pure water was 25 °.

  Next, a hole injection layer was formed as a first organic EL layer. First, the surface of the substrate was washed with ozone water (concentration: 2 ppm, treatment time: 5 minutes) using an ozone water production apparatus (FA-1000ZW12-5C manufactured by Loki Techno Co., Ltd.). By this cleaning, the contact angle between the surface of the first electrode (ITO thin film) and pure water was reduced to 5 ° or less, and sufficient wettability could be imparted to the surface of the first electrode (ITO thin film). . Next, an ink (poly (ethylenedioxythiophene) (PEDOT) / polystyrene sulfonic acid (PSS) aqueous dispersion having a solid content concentration of 1.5% by weight (Bayer AI4083) using an inkjet device (Litlex142P manufactured by ULVAC) ) Was applied to each recess. Since the ink was repelled by the top surface of the partition wall having a high contact angle, the ink was prevented from overflowing to the adjacent area through this top surface and was accommodated in the recess. On the other hand, the ink accommodated in the concave portion was filled so as to be sucked into a tapered portion where the first electrode and the partition wall were connected by capillary action, and spread uniformly in the concave portion. The substrate was baked at 200 ° C. to form a hole injection layer (film thickness 50 nm) with a uniform film thickness (see FIG. 6B). The film thickness here means the film thickness at the center of the recess.

  Next, three types of light emitting layers were formed. First, the polymer light-emitting material 1 that emits red light was mixed with an organic solvent so that the concentration thereof was 0.8 wt% to prepare red ink. Similarly, the polymer light-emitting material 2 that emits green light was mixed with an organic solvent so that the concentration thereof was 0.8 wt% to prepare green ink. Then, the polymer light emitting material 2 that emits blue light was mixed with an organic solvent so that the concentration thereof was 0.8 wt% to prepare blue ink. Each of these red, green, and blue inks was applied into a predetermined recess using an inkjet device (Litrex142P manufactured by ULVAC). Since the ink was repelled by the top surface of the partition wall having a high contact angle, the ink was prevented from overflowing to the adjacent area through this top surface and was accommodated in the recess. On the other hand, the ink accommodated in the concave portion was filled so as to be sucked into a tapered portion where the first electrode and the partition wall were connected by capillary action, and spread uniformly in the concave portion. By firing this substrate at 130 ° C., a light emitting layer (film thickness 60 nm) having a uniform film thickness was formed (see FIG. 6B). As the polymer light emitting material, for example, a light emitting layer can be formed by using a material made by Summation.

  Next, a layer made of NaF (2 nm), a layer made of Mg (2 nm), and a layer made of Al (200 nm) were sequentially laminated by a vacuum vapor deposition method to form a second electrode (cathode), a connection portion, and a contact conductor. . Then, the sealing substrate was bonded together, the organic EL element was sealed, and the display apparatus was produced.

  The lower part of the partition wall around the pixel after the light emitting layer was formed was filled with an organic EL layer, and a shape without a step was obtained from the partition surface to the organic EL layer surface. Therefore, an Al second electrode having a film thickness of 200 nm was formed continuously over all organic EL elements. Thus, even if the periphery of the pixel is a reverse-tapered partition wall, the thin cathode does not break. Further, since the partition wall itself is formed in a forward taper shape in the cathode contact region, even a thin connection portion and contact conductor are not disconnected. It was confirmed that the manufactured display device normally emitted light in the entire light emitting region provided with the organic EL element.

DESCRIPTION OF SYMBOLS 1 Display apparatus 2 Board | substrate 3 Partition 3a End part by the side of the board | substrate 2 of the partition 3 3b End part by the side opposite to the board | substrate 2 of the partition 3 4 Organic EL element 5 Recessed part 6 1st electrode 7 1st organic EL layer ( Hole injection layer)
7a Tapered portion 8 Partition forming film 9 Second organic EL layer (light emitting layer)
DESCRIPTION OF SYMBOLS 10 2nd electrode 20 Electrode wiring 21 Photomask 21a 1st photomask 21b 2nd photomask 22 Contact conductor 23 Connection part 30 Display area 31 Contact area 32 Peripheral part 51 Partition 52 Organic EL element 53 1st electrode 54 Organic EL layer 55 Organic EL layer 56 Second electrode 57 Tip portion 58 Substrate 61 Connection portion 62 Contact conductor 63 Electrode wiring

Claims (4)

A substrate,
A plurality of organic EL elements provided in a display region on the substrate;
A display device that defines a region in which the organic EL element is provided and a partition wall that defines a contact hole provided outside the display region;
The plurality of organic EL elements include a first electrode, a second electrode provided farther from the substrate than the first electrode, and one or more organic EL layers provided between the electrodes. Have
The second electrode has a connection portion extending on the partition wall from the display region to the contact hole,
The end of the partition on the substrate side is
In the display area, an angle formed between the side surface and the bottom surface is formed to be an obtuse angle,
In the region where the contact hole is formed, the display device is formed such that an angle formed between the side surface and the bottom surface is an acute angle.   2. The display device according to claim 1, wherein an end of the partition opposite to the substrate side is formed so that an angle formed between a side surface and a bottom surface of the display region is an acute angle.   The display device according to claim 1, wherein a surface of the second electrode on the substrate side is formed so as to be separated from the substrate as approaching the partition from the central portion of the organic EL element. A method for manufacturing the display device according to claim 1,
A negative photoresist is applied on the substrate to form a partition forming film, and the partition forming film is exposed and developed with different exposure amounts in the display region and the region in which the contact hole is provided. The manufacturing method of the display apparatus which has the process of forming the said partition by.

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