JP2011023305A - Substrate for organic el element, method of manufacturing organic el layer, organic el element, and plate member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a substrate for organic EL elements capable of forming flat and high-performance organic EL layers having a small amount of unevenness in a film thicknesses. <P>SOLUTION: The substrate 1 for organic EL elements includes: a plurality of partitions 43 disposed on a support substrate in parallel; a plurality of plate members 44 for prevention of an ink flow disposed in a direction crossing the plurality of partitions; and at least one pixel electrode 41 disposed inside a partitioned area 41b partitioned by the partitions and the plate members. The plate members 44 are disposed while both ends abut on the partitions 43, and include a constriction 44a caused by a decrease in a thickness from both ends toward the center. A flow of ink supplied to the partitioned area 41b to the adjacent partitioned area 41b in a direction parallel to the partitions 43 is suppressed, and further the ink is uniformly separated on the plate members 44 including the constriction for falling into the partitioned area, thus forming the flat and high-performance organic EL layer having a small amount of unevenness in film thickness. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a substrate used for manufacturing an organic electroluminescence (hereinafter referred to as “organic EL”) element, a method for manufacturing an organic EL layer using the substrate, an organic EL element, and the substrate. It is related with the plate-shaped member made.

  An organic EL element and an organic EL display device on which the organic EL element is mounted have already been put into practical use for mobile phones and the like. An organic EL element is a laminate having an anode and a cathode, and one or more organic EL layers including a light emitting layer sandwiched between these electrodes. The light emitting layer is formed of an organic compound that emits light when a voltage is applied and a current flows. An organic EL element has various characteristics, but since it can be formed by laminating thin films, one major feature is that a device such as a display device on which the organic EL element is mounted can be made extremely thin.

An organic EL element is usually produced by laminating an electrode and one or more organic EL layers including a light emitting layer on a supporting substrate in a predetermined order, and a display element is manufactured by arranging a large number of organic EL elements. The In a display element using an organic EL element that has already been put into practical use, the organic EL layer of each organic EL element is formed using a vacuum evaporation method using a mask. However, due to the problem of patterning accuracy due to the deflection of the mask and the problem of film formation cost due to the necessity of a large vacuum apparatus, it is difficult to increase the screen.
On the other hand, as a method for forming an organic EL layer, a coating method has been studied. The coating method is a method for forming a layer by applying a component constituting an organic EL layer, that is, an ink containing an organic EL material, and curing the ink by drying or the like. Examples of the coating method include an inkjet method (droplet coating method). The inkjet method is capable of precisely controlling the coating amount of the organic EL material and is capable of precise position control in units of several microns, and is being developed as a technology for increasing the screen size. However, the ink jet method (droplet application method) has a problem that the nozzle holes are easily blocked because the ink is ejected as droplets from the nozzles.

Therefore, a nozzle printing method (liquid column coating method) has been researched and developed as a technique replacing the ink jet method (for example, Patent Documents 1 to 3).
The nozzle printing method is a method in which ink is continuously ejected from a discharge nozzle as a liquid column and applied onto a substrate. In addition to the same advantages as the ink jet method described above, nozzle holes are not easily blocked. There is an advantage.

JP 2002-75640 A JP 2009-43499 A JP 2007-188862 A

By the way, in film formation using a wet process such as an ink jet method or a nozzle printing method, a method of providing a partition wall corresponding to a coating pattern for forming a large number of organic EL elements on a substrate and controlling a coating region is generally used. It has been adopted.
Usually, as a partition shape used in continuous liquid column coating such as a nozzle printing method, a stripe-shaped partition parallel to the coating direction (nozzle scan direction) as disclosed in Patent Document 1 is used. The ink is gradually dried after being ejected from the nozzle. Before the ink is dried, the ink flows in the longitudinal direction of the partition (hereinafter, also referred to as “stripe direction”) in the partition. This contributes to uneven thickness of the organic EL layer. The main causes of ink flow are the following two points, that is, as the first point, since the ink is liquid and has surface tension, the force to gather into a spherical shape works due to the surface tension of the ink itself, and the ink flow As a second point, there is a region where there is no partition wall at the end of the stripe-shaped partition wall, and the outflow of ink from this end portion can be cited as a cause. It is considered that the ink flows and contributes to uneven thickness of the organic EL layer after drying.
Further, the substrate disclosed in Patent Document 2 is provided with protrusions between regions provided between stripe-shaped partition walls, but the regions in the stripe direction are still connected, Eventually, the ink flows, and the ink flow between the respective regions cannot be suppressed. Further, due to the shape of the protrusion, the film thickness in the pixel becomes uneven, which causes a decrease in the light emission characteristics of the organic EL element.
Furthermore, when applying a liquid column to a box-shaped partition wall used in the ink jet method, each of the regions partitioned by the partition wall has a separated structure, so that the ink supplied in the region is separated. Thus, it is possible to avoid flowing into the adjacent region, and it is possible to avoid the flow of ink in the stripe direction, which has occurred in the stripe-shaped partition wall. However, in the liquid column application, since the coating is applied also on the partition wall having a thickness provided in the direction intersecting the scanning direction, the ink on the partition wall is partitioned by the partition wall (hereinafter referred to as “partition partition region”). It is impossible to control which side of the partition wall falls when falling into the partition wall, and the amount of ink supplied to the partition wall partition region varies depending on each region, and the organic EL layer is separated between the partition wall partition regions. The film thickness was uneven.

In contrast, in Patent Document 3, a stripe-shaped partition wall is provided in a direction parallel to the scan direction of the nozzle, and a mountain-shaped partition wall portion having a height lower than that of the stripe-shaped partition wall in a direction intersecting the scan direction. A provided substrate is disclosed. This chevron-shaped partition wall can separate each partition wall partition region similarly to the box-shaped partition wall described above, and can suppress a crosstalk phenomenon caused by a current flowing through a connection between pixels. Further, since there is no flat portion at the top, it is promoted that the ink falls into the partition wall region, and the ink can be prevented from remaining on the partition wall.
However, since only the mountain shape, that is, the cross-sectional shape of the partition wall, is defined, the separation point where the ink is separated on the partition wall that intersects the scanning direction cannot be controlled, and the ink for each partition wall cannot be controlled. Separation points differ, and ink separation occurs in a non-uniform manner and falls into the partition wall partition region. For this reason, the amount of ink liquid is different on both sides of the partition wall, which causes uneven film thickness after drying.

  Under such circumstances, an object of the present invention is to provide a substrate for an organic EL element that can easily form a flat and high-quality organic EL layer with less unevenness of ink supply onto the pixel electrode.

  The organic EL element substrate of the present invention includes a plurality of partition walls arranged in parallel on a support substrate, a plurality of ink flow preventing plate-like members disposed in a direction intersecting the plurality of partition walls, and the partition walls. And at least one or more pixel electrodes arranged in a region partitioned by the plate-like member, wherein the plate-like member is arranged so that both ends thereof are in contact with the partition wall. And it has the constriction by the reduction | decrease in the thickness toward the center part from both ends, It is characterized by the above-mentioned.

  A plate-like member for preventing ink flow (hereinafter simply referred to as “plate-like member”) in a direction intersecting with a plurality of parallel partitions (hereinafter sometimes referred to as “stripe-shaped partition walls”) arranged on the support substrate. Are arranged between adjacent partition walls, and both ends thereof are disposed in close contact with the partition wall, so that the region is defined by the partition wall and the plate-like member. It is possible to suppress ink applied continuously in a liquid column shape (hereinafter sometimes referred to as “partition region”) from flowing in the stripe direction before drying. Furthermore, since the plate-like member has a constriction due to a decrease in thickness in the stripe direction from both end portions to the center portion, the plate-like member maintains a close contact with the substrate while maintaining a close area on both sides of the plate-like member. Ink can be separated uniformly. As a result, it is possible to perform good film formation in which unevenness in film thickness in the stripe direction is suppressed. In the present invention, the constriction of the plate-like member is due to a decrease in thickness from both end portions to the central portion of the plate-like member, and it is possible to determine the presence or absence of constriction as seen from the vertical direction of the substrate. .

From the viewpoint of ink separation, it is effective that the plate-like member is thin.
The ink supplied from the nozzles is also applied to the plate-like member, and the ink on the plate-like member is separated and flows down into the partitioned areas on both sides of the plate-like member by gravity and surface tension. Ink separation occurs anywhere on the plate-like member, but if the plate is thick, the ink separation point cannot be controlled, resulting in large variations in the ink separation point, which causes uneven film thickness. It is to become. Further, by forming a mountain shape as in Patent Document 3, it is possible to promote the drop of ink into the pixels, but the separation point in the stripe direction cannot be controlled. Further, if the thickness of the plate member is reduced to a level sufficient to control the separation point, there arises a problem that the plate member is peeled off from the substrate. Further, the method of reducing the chevron shape and the plate thickness does not lead to controlling the separation point in the direction intersecting the stripe, that is, the direction parallel to the plate member. Therefore, in the present invention, the plate-like member has the constriction, whereby the ink separation point can be completely controlled. In addition, in the present invention, since the plate-like member can be thickened at both ends as long as the center portion is constricted, the adhesion to the barrier, and hence the adhesion to the substrate, is improved. It is also possible to prevent peeling.

  In the organic EL element substrate of the present invention, it is desirable that the pixel electrodes are arranged at regular intervals in the longitudinal direction of the partition wall, and in this case, as few as possible within a range in which the effect of suppressing ink flow can be maintained. More desirably, a plate-like member is disposed. In particular, when the arrangement interval D in the longitudinal direction of the partition walls of the plate-like member is 2 to 10 times, preferably 2 to 5 times the arrangement interval L of the pixel electrodes, a more uniform film is formed. Can be formed.

In addition, from the viewpoint of the film thickness uniformity of the partition region and the peeling resistance of the plate-like member, the minimum plate thickness t of the constriction in the plate-like member, and the interval L at which the pixel electrodes are arranged in the longitudinal direction of the partition wall, It is desirable to satisfy the following formula (1). Here, the minimum thickness t of the constriction is determined by the thickness when projected from the vertical direction of the substrate.

L / 60 ≦ t ≦ L / 15 (1)

As described above, in order to uniformly separate the ink into the divided areas on both sides of the plate-like member, it is desirable that the minimum plate thickness of the constriction is thin, but if it is too thin, the plate-like member may be peeled off. In addition, when the pixel electrode arranged on the substrate is large, the distance between adjacent partition walls may be large, and the length of the plate member is accordingly increased. It becomes easy. In addition, the larger the pixel electrode, the larger the partition area, so that it is less affected by variations in the amount of ink supplied. Therefore, as the partition area increases, the optimum thickness of the constricted portion is relatively increased. be able to.
As a result of intensive studies, we have found that there is a correlation of the above formula (1) between the arrangement interval L of the pixel electrodes and the plate thickness t of the optimum neck portion.
For example, when the distance L is 180 μm, the optimum thickness t is from 3 μm to 12 μm from the equation (1).
When t is smaller than L / 60, the plate-like member is easily peeled off, which is not preferable. When it is larger than L / 15, the amount of ink in the partitioned area is likely to vary, and the film thickness of the partitioned area. This is not preferable because the uniformity is lowered.

  In the method for producing an organic EL layer of the present invention, an ink containing an organic EL material is disposed between two partition walls arranged in parallel on the above-described organic EL element substrate along the longitudinal direction of the partition wall. The organic EL layer is obtained by coating and drying.

  The organic EL layer produced by the method of the present invention is flat and has high quality with reduced film thickness unevenness. Therefore, when the organic EL element having an organic EL layer obtained by this production method is used in an organic EL device, display unevenness is suppressed, the quality is good, the light emission characteristics are good, and the durability is high. high.

  Further, the plate member for ink flow prevention according to the present invention is characterized by having a constriction due to a decrease in thickness from both ends toward the center, and between two parallel partitions arranged on the substrate, The both end portions are used in contact with two partition walls. By disposing this plate-like member as described above, it is possible to obtain an organic EL element substrate capable of good film formation with suppressed film thickness unevenness.

  According to the present invention, it is possible to form a high-quality organic EL layer that is flat and has no film thickness unevenness.

It is a top view of the substrate for organic EL elements concerning the embodiment of the present invention. FIG. 2 is a partially enlarged plan view of the substrate of FIG. 1. It is sectional drawing in the AA in FIG. It is a figure which shows the structure of the plate-shaped base material which concerns on embodiment of this invention. It is a figure which shows the structure of the plate-shaped base material which concerns on other embodiment of this invention. It is a figure which shows the structure of the plate-shaped base material which concerns on other embodiment of this invention. It is a figure which shows the structure of the plate-shaped base material which concerns on other embodiment of this invention. It is a figure which shows the structure of the plate-shaped base material which concerns on other embodiment of this invention. It is a figure which shows the structure of the plate-shaped base material which concerns on other embodiment of this invention. It is a figure which shows the movement of the nozzle and panel (board | substrate) in the application | coating process of embodiment of this invention. It is a figure which shows the track | orbit of the nozzle in an application | coating process. It is sectional drawing just after ink application of the organic EL element substrate which concerns on embodiment of this invention (before drying). It is sectional drawing after the ink drying of the board | substrate for organic EL elements which concerns on embodiment of this invention. It is a figure which shows the track | orbit of the nozzle in the application | coating process of multi-color ink. It is sectional drawing just after the ink application of the organic EL element substrate of Comparative Example 1 (before drying). It is sectional drawing after the ink drying of the organic EL element substrate of Comparative Example 1. It is sectional drawing just after ink application of the organic EL element substrate of Comparative Example 2 (before drying). It is sectional drawing after the ink drying of the organic EL element substrate of Comparative Example 2.

  The present invention includes a plurality of partition walls arranged in parallel on a support substrate, a plurality of plate members for preventing ink flow arranged in a direction intersecting the plurality of partition walls, and the partition walls and the plate members. An organic EL element substrate having at least one or more pixel electrodes arranged in a partitioned region (partition region), wherein the plate-like member has both end portions in close contact with the two partition walls. The present invention relates to an organic EL element substrate (hereinafter also referred to as “substrate of the present invention”) that is disposed and has a constriction due to a decrease in thickness from both ends toward the center.

Hereinafter, preferred embodiments of the substrate of the present invention will be described with reference to the drawings.
For ease of understanding, the pixel arrangement of the substrate in this embodiment is exemplified by an array of monochromatic organic EL elements provided in a row, but is not limited to this, and the gist of the present invention As long as it does not deviate from the above, it can be appropriately changed. For example, as shown in FIG. 8, the present invention can be applied as a substrate for obtaining an organic EL device having a pixel array in which a plurality of colors of organic EL elements are periodically arranged by applying a plurality of colors of ink. Further, the scale of each member in the drawing may be different from the actual scale.

FIG. 1 is a plan view showing an organic EL element substrate according to an embodiment of the present invention, FIG. 2 is a partially enlarged plan view of the substrate according to the embodiment of the present invention, and FIG. It is sectional drawing in A line.
The organic EL element substrate 1 in the embodiment of the present invention is a panel in which four matrix portions (display area portions) 40 are provided on a support substrate 30. In the matrix section 40, 41 is a pixel electrode, 41a is a row of pixel electrodes, 41b is a partition region, 42 is a pixel regulating layer, 43 is a partition wall, and 44 is a plate member for preventing ink flow. Note that a pixel refers to a light emitting region defined by a pixel regulation layer.

  The support substrate 30 may be any material as long as it is chemically stable when forming an electrode or an organic EL layer. For example, glass, plastic, polymer film, silicon substrate, metal plate, and the like are laminated. Used.

  In the matrix section 40, the pixel electrodes 41 are regularly arranged in a series of several rows, and each is partitioned by a pixel regulating layer 42 surrounding the pixel electrodes. Although described in detail later, an organic EL layer is formed by sequentially laminating various layers including a light emitting layer on the pixel electrode 41. At least one of the layers constituting the organic EL layer is a light emitting layer, and examples of the other organic EL layers include a hole transport layer and an electron block layer described later. The organic EL layer uses an ink that is a solution, a suspension, or a colloidal dispersion containing a material (hereinafter referred to as “organic EL material”) such as a light emitting layer (hereinafter referred to as “organic EL material”) and an ink solvent. Produced. In this specification, the term “solvent” is used as a concept including both a liquid for dissolving the organic EL material and a liquid for dispersing the organic EL material, unless otherwise specified.

The pixel regulating layer 42 is provided for the purpose of defining a light emitting region and ensuring insulation from the electrode wiring arranged on the substrate, and is partitioned by the pixel regulating layer 42 so that the pixel electrode 41 is fixed. Arranged at intervals.
The material of the pixel regulation layer 42 is preferably an insulator, and examples thereof include inorganic oxides such as SiO ₂ , inorganic nitrides such as SiN, and heat resistant resin materials such as polyimide and novolac resin.

The barrier ribs 43 are stripe-shaped barrier ribs arranged in parallel between the pixel electrode columns 41 a at regular intervals so as to divide the pixel electrode columns 41 a including the pixel electrodes 41 one by one. The partition wall 43 is parallel to the direction in which ink is continuously applied (nozzle scan direction) in nozzle printing described later.
The partition walls 43 are arranged to prevent the ink applied to the pixel electrode columns 41 a from being mixed between the columns. Therefore, the height of the partition wall 43 is designed to be high enough to hold the applied ink.
The partition wall 43 may be an electrically insulating material, and examples thereof include an insulating resin material such as polyimide and novolac resin. Moreover, in order to improve the holding | maintenance performance of the apply | coated ink, you may provide the liquid repellency which repels an ink on the surface of a partition. For example, the partition walls can be made liquid repellent by CF ₄ plasma treatment.

  The ink flow preventing plate-like member 44 (hereinafter also simply referred to as “plate-like member 44”) is arranged so as to divide the column 41a of the pixel electrodes 41 in a direction intersecting with the partition walls 43. That is, the pixel electrode 41 is disposed in a region 41 b defined by the partition wall 43 and the plate-like member 44. In the present embodiment, the partition wall 43 and the plate-like member 44 intersect perpendicularly, but do not necessarily intersect perpendicularly.

The plate-like member 44 is arranged so that both end portions thereof are in close contact with the two partition walls so that the ink does not flow in the pixel electrode rows 41a through the gaps.
Further, as shown in the enlarged view in FIG. 4-1, the plate-like member 44 has a chevron shape with a constriction due to a decrease in thickness from both ends toward the center, and the center line in the film thickness direction. It has a vertex in the vicinity. Although details will be described later in conjunction with the manufacturing process, since the structure has such a constriction, it is possible to uniformly separate the ink into the pixels while preventing the plate-like member from peeling off from the substrate.

Here, it is preferable that the minimum thickness t (see FIG. 4-1) of the constriction in the plate-like member and the arrangement interval L of the electrodes satisfy the following formula (1).
L / 60 ≦ t ≦ L / 15 (1)

By satisfying this relationship, it is possible to effectively suppress the occurrence of ink unevenness while preventing peeling of the plate-like member from the substrate.
In the plate member 44 of the present embodiment, t = 5 μm, L = 180 μm, and t = L / 36.

  Note that the shape of the plate-like member 44 is not limited to the shape of FIG. 4A, and may be any structure that has a constriction due to a decrease in thickness from both ends toward the center. For example, a plate-like member 45 having a rectangular cross section parallel to the end face shown in FIG. 4B, a plate-like member 46 having a trapezoidal cross section parallel to the end face shown in FIG. Further, as shown in FIG. 4-4 (plate member 47), FIG. 4-5 (plate member 48), and FIG. The cross sections parallel to each other may have a substantially chevron shape, a substantially rectangular shape, or a substantially trapezoidal shape.

In the substrate of the present embodiment, the partition walls 43 are arranged at regular intervals, and the plate-like members 44 are arranged at regular intervals for every two pixel electrodes 41. Although details will be described later in the film forming step, since the plate-like member 44 is disposed for each two-pixel electrode 41, the ink amount surrounds the two-pixel electrode 41 by the partition wall 43 and the plate-like member 44. Since averaging is performed in the partition region 41b, the film thickness unevenness of the formed film is reduced. In addition, the influence of ink adhesion on the plate-like member 44 is alleviated.
The plate-like members 44 are arranged at as wide intervals as possible within a range in which the film thickness unevenness due to ink flow does not occur.
Here, as shown in FIG. 2, if the arrangement interval L of the pixel electrodes 41 is defined as the center-to-center interval of the pixel electrodes 41 in the longitudinal direction, the arrangement interval D of the plate-like members is from the viewpoint of suppressing unevenness. The pixel electrode arrangement interval L is preferably 2 to 10 times (more preferably 2 to 5 times).
If it is less than twice, when the ink is deposited on the plate-like member 44 and the film thickness unevenness occurs, the film thickness unevenness may exceed the allowable amount from the viewpoint of display quality and light emission characteristics. Yes, if it exceeds 10 times, the effect of forming the plate-like member 44 may not be obtained.
Within such a range, the unevenness factor can be suppressed in a balanced manner, so that a film with higher uniformity can be formed.
In the present embodiment, since the plate-like member 44 is arranged for every two pixel electrodes 41, there is a relationship of D = 2L.

Next, the manufacturing method of the organic EL element which concerns on embodiment of this invention using the board | substrate 1 for organic EL elements of this invention is demonstrated with reference to drawings. In the present invention, a laminate of at least a pair of electrodes and one or more organic EL layers including a light emitting layer sandwiched between the electrodes is defined as an “organic EL element”, and the organic EL elements are arranged two-dimensionally. The flat display device thus formed is defined as “organic EL device”. The “organic EL layer” means a layer made of an organic EL material.
For ease of understanding, the scale of each member in the drawings may differ from the actual scale. Further, the present invention is not limited by the following description, and can be appropriately changed without departing from the gist of the present invention.
In addition, there are members such as electrode lead wires in organic EL devices, but various aspects of electrical wiring, electrical circuits, etc. are implemented based on ordinary knowledge in the technical field of light emitting elements, display devices, etc. Since it is possible and is not directly related to the description of the present invention, a detailed description is omitted.

5 and 6 show the state of the ink application process by nozzle printing. In addition, in FIG.5, FIG6 and FIG.8, the description of a plate-shaped member is abbreviate | omitted.
The organic EL element substrate 1 in which four matrix portions (display area portions) 40 are provided on the support substrate 30 is transported in the Dd direction. Ink for forming the layer of the laminate is ejected from the nozzle 20 of the nozzle printing apparatus (main body not shown). The nozzle 20 repeatedly moves in a direction Nm orthogonal to the transport direction Dd of the organic EL element substrate.

  Ink is ejected continuously as a liquid column intermittently. The nozzle printing apparatus is an apparatus that can continuously eject ink from minute nozzles. The nozzle printing apparatus is suitable for coating in a non-intermittent continuous line stably with a fine line width.

  The ink used is a solution, suspension, or colloid containing a material such as a hole transport layer, an electron blocking layer, a light emitting layer, etc. (hereinafter referred to as “organic EL material”) and an ink solvent constituting the organic EL element. It is a solution. In this specification, the term “solvent” is used as a concept including both a liquid for dissolving the organic EL material and a liquid for dispersing the organic EL material, unless otherwise specified.

  The ink solvent may be appropriately selected depending on conditions such as solubility of the organic EL material and affinity with the substrate. As the ink solvent, it is preferable to satisfy various requirements as an ink solvent in terms of volatility, solubility or dispersibility of the layer forming component, and the like. The ink solvent is preferably, for example, one or a mixture of two or more selected from the group consisting of water, alcohol solvents, glycol solvents, ether solvents, ester solvents, chlorine-containing solvents and aromatic hydrocarbon solvents. . Examples of the alcohol solvent include methanol, ethanol, propanol, isopropanol, butanol and the like. Examples of the glycol solvent include ethylene glycol and propylene glycol. Examples of the ether solvent include tetrahydrofuran, methoxybenzene and the like. Examples of the ester solvent include ethyl acetate and butyl acetate. Examples of the chlorine-containing solvent include chloroform, chlorobenzene, and methylene chloride. Examples of the aromatic hydrocarbon solvent include toluene, xylene, trimethylbenzene, tetramethylbenzene and the like.

  As shown in FIG. 5, the organic EL element substrate 1 is transported under the nozzle 20, and when the nozzle repeatedly moves in the Nm direction, the nozzle 20 relatively draws a trajectory Ip shown in FIG. 6. Will move on the panel. The trajectory Ip of the nozzle 20 moves the pixel electrode column 41a by one column in the longitudinal direction, then moves to the next column, and moves a new pixel electrode column 41a in the longitudinal direction. When the panel 1 passes below the nozzle 20, ink is ejected from the nozzle 20, and ink is applied to the partition area 41b one after another while drawing a locus as shown in FIG.

  Since the ink is continuously ejected from the nozzle 20 in a liquid column state intermittently, as shown by the track Ip, the ink is separated from the partition region 41b and the plate-like member 44 in the longitudinal direction of the partition region 41b. It is also applied intermittently and continuously. Therefore, the ink is applied in a non-intermittent linear manner on the plurality of partition regions 41b and the plate-like member 44 arranged in the longitudinal direction of the partition region 41b. The partition area 41b is partitioned by the partition wall 43 and the plate member 44, and the ink applied in the partition area 41b spreads in the area.

  FIGS. 7A and 7B are diagrams schematically showing a state of the partition region 41b in the process of drying after the ink is applied. FIG. 7-1 is a cross-sectional view immediately after ink application (before drying) of the organic EL element substrate according to the embodiment of the present invention, and FIG. 7-2 is a cross-sectional view after the ink drying.

  In the embodiment of the present invention, ink is intermittently ejected continuously as a liquid column, and the ink is continuously and intermittently applied onto the partition region 41b and the plate-like member 44 in the longitudinal direction of the partition region 41b. Meanwhile, the ink is applied linearly on the plurality of partition regions 41b and the plate-like member 44 arranged in the longitudinal direction of the partition region 41b.

  Since the partition wall has a sufficient height, the applied ink does not enter the adjacent partition region 41b beyond the partition wall. Moreover, in order to prevent further mixing, the partition wall 43 may be subjected to a liquid repellent treatment for repelling ink. The ink 51 applied on the plate-like member 44 is uniformly separated and flows down from the plate-like member 44 into the partition region 41b during drying, and finally a part of the layer is formed in the partition region 41b. Constitute. After the ink application is completed, the substrate 30 is placed in a predetermined atmosphere in the drying process, and the solvent evaporates from the ink and hardens to form a layer.

  As described above, in the present invention, the plate-like member 44 having a constriction whose thickness decreases from both ends toward the center is disposed. Therefore, it is possible to suppress the ink applied in a liquid column shape continuously to the plurality of partitioned regions 41b partitioned by the partition walls and the plate-like member from flowing in the stripe direction before drying. Further, the ink applied on the plate-like member 44 is uniformly separated on both sides of the plate-like member 44, and can flow down to the partition region 41b. As a result, the amount of ink supplied into each partition region 41b is made uniform, and the film thickness of the organic EL layer obtained by drying the ink can be made uniform.

  Further, the surfaces of the partition wall 43 and the plate-like member 44 may have water repellency to repel ink in order to hold the ink well. As a method for imparting liquid repellency, a liquid repellent component may be mixed with a component constituting the partition wall or plate member, or a liquid repellent film may be formed on the surface of the partition wall or plate member. It may be provided. In order to better prevent the flow of the applied ink in the stripe direction, at least the plate-like member 44 is preferably provided with liquid repellency, and it is more possible for the ink to enter the adjacent partition region 41b beyond the partition wall. In order to prevent it well, it is more preferable that the entire surfaces of the partition wall 43 and the plate-like member 44 have liquid repellency.

  From the viewpoint of effectively separating the ink while preventing the peeling of the plate member from the support substrate, it is important that the plate member has a constriction. When there is no constriction and the plate is thick, it is impossible to control where the ink is separated on the upper surface of the plate, and the variation in the position where the ink is separated becomes large, resulting in uneven thickness. Moreover, when there is no constriction and a plate | board thickness is thin, adhesiveness with a board | substrate will fall and a plate-shaped member will peel from a board | substrate. By providing the constriction, the separation of the ink from the thin part of the constricted portion is suppressed while maintaining the adhesion of the plate-like member to the substrate and suppressing the separation, and the variation in the position where the ink is separated is suppressed satisfactorily. Therefore, the film thickness unevenness is suppressed.

  In the ink drying process following the ink application process, the solvent is distilled off from the ink, and the organic EL material is fixed to the partition region 41b. What is necessary is just to select the drying temperature of an ink suitably according to the solvent etc. which were used. Moreover, you may provide the process of baking an ink after the above drying.

As described above, the organic EL element substrate in which the monochromatic organic EL elements arranged in a row as the pixel array is illustrated, but the organic EL element substrate having the pixel array in which the organic EL elements of a plurality of colors are periodically arrayed. Is also applicable.
Such an application process of a plurality of colors of ink will be described with reference to FIG. In FIG. 8, the matters already described in the above-described single color ink application step are denoted by the same reference numerals, and the description thereof is omitted.
As shown in FIG. 8, a device provided with three nozzles (triple nozzles) 21 is used for supplying ink. Each nozzle of the triple nozzle is a nozzle N _B to the discharge nozzle N _R for ejecting ink containing a red light-emitting material, a nozzle N _G for ejecting ink containing a green light-emitting material, an ink containing a blue luminescent material. The triple nozzle 21 stands by at the initial position (P ₁ ). After completion of the predetermined alignment, the ink moves in the moving direction Nm ₁ while ejecting the respective inks intermittently and continuously from the three nozzles. When the triple nozzle 21 reaches the position (P ₂ ), the panel 1 is moved in the transport direction Dd, and the movement of the panel is stopped when the triple nozzle 21 reaches the position (P ₃ ). The triple nozzle 21 moves in the moving direction Nm ₃ and stops when reaching the position (P ₄ ). Such operation is repeated, and ink is sequentially applied to the pixel electrodes in the partition area on the panel.
In the case of a pixel array in which organic EL elements of a plurality of colors are periodically arranged (for example, a pixel array of an organic EL color display), the light emitting areas of the plurality of colors are collectively referred to as pixels, In some cases, the light emitting region is referred to as a sub-pixel. In this case, the present invention can be applied to the sub-pixel as well.

Next, the structure of the organic EL element mounted on the organic EL device that can be manufactured by the manufacturing method of the present invention will be described more specifically.
The organic EL element is a laminate formed of at least a pair of electrodes and an organic EL layer including a light emitting layer sandwiched between the electrodes. As will be described below, the organic EL element may be provided with various types of organic EL layers in addition to the light emitting layer. In addition, the layer stacking order and the like can be variously modified.

The organic EL device produced according to the present invention is not limited to the following organic EL device. Further, in the manufacturing method of the present invention, at least one of the organic EL layers constituting the organic EL element uses ink, and a predetermined coating process and drying as shown in the above-described embodiment and the like. A layer formed by a process including a process. Therefore, in forming other layers, the layers may be formed by other methods.
In general, each organic EL layer constituting the organic EL element is extremely thin, and various film forming methods can be employed for forming the layer. Therefore, in the following description, the layer formation may be referred to as film formation.

  In addition to having an anode, a light emitting layer and a cathode as essential, the organic EL device has another layer between the anode and the light emitting layer and / or between the light emitting layer and the cathode. Can do.

  As the anode of the organic EL element, it is preferable to use a transparent electrode that can transmit light because an element that emits light through the anode can be configured. As such a transparent electrode, a metal oxide, metal sulfide or metal thin film having high electrical conductivity can be used, and a material having a high transmittance can be suitably used, which is appropriately selected depending on the organic layer to be used. Specifically, at least one of a thin film made of indium oxide, zinc oxide, tin oxide, ITO, indium zinc oxide (abbreviated as IZO), gold, platinum, silver, copper, aluminum, or a metal thereof is used. An alloy containing more than one type is used.

As a material for the cathode, a material having a small work function and easily injecting electrons into the light emitting layer and / or a material having a high electric conductivity and / or a material having a high visible light reflectance are preferable. As the metal, an alkali metal, an alkaline earth metal, a transition metal, or a group III-B metal can be used.

  The light emitting layer contains an organic compound. Usually, organic substances (low molecular compounds and high molecular compounds) that mainly emit fluorescence or phosphorescence are included. Further, a dopant material may be further included. Examples of the material for forming the light emitting layer that can be used in the present invention include the following dye-based materials, metal complex-based materials, polymer-based materials, and dopant materials.

  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, trifumanylamine derivatives, oxadiazole dimers, pyrazoline dimers, and the like.

  Examples of the metal complex material include metal complexes that emit light from triplet excited states such as iridium complexes and platinum complexes, aluminum quinolinol complexes, benzoquinolinol beryllium complexes, benzoxazolyl zinc complexes, benzothiazole zinc complexes, azomethyls. Zinc complex, porphyrin zinc complex, europium complex, etc., which has Al, Zn, Be or the like as the central metal or rare earth metal such as Tb, Eu, or Dy, and the ligand is oxadiazole, thiadiazole, phenylpyridine, phenylbenzo Examples thereof include metal complexes having an imidazole or quinoline structure.

  Polymeric materials include polyparaphenylene vinylene derivatives, polythiophene derivatives, polyparaphenylene derivatives, polysilane derivatives, polyacetylene derivatives, polyfluorene derivatives, polyvinylcarbazole derivatives, and polymerized chromophores and metal complex light emitting materials. Etc.

  A dopant can be added to the light emitting layer for the purpose of improving the light emission efficiency and changing the light emission wavelength. Examples of such dopant materials include perylene derivatives, coumarin derivatives, rubrene derivatives, quinacridone derivatives, squalium derivatives, porphyrin derivatives, styryl dyes, tetracene derivatives, pyrazolone derivatives, decacyclene, phenoxazone, and the like. In addition, the thickness of the light emitting layer is usually about 2 nm to 2000 nm.

  In an organic EL element, one light emitting layer is usually provided, but not limited to this, two or more light emitting layers may be provided. In that case, two or more light-emitting layers can be stacked in direct contact with each other, and a layer other than the light-emitting layer can be provided between the layers.

  Next, layers other than the anode, the light emitting layer, and the cathode in the organic EL element will be described.

  Examples of what is provided between the anode and the light emitting layer include a hole injection layer, a hole transport layer, and an electron block layer. When both the hole injection layer and the hole transport layer are provided, the layer close to the anode is the hole injection layer, and the layer close to the light emitting layer is the hole transport layer. In addition, when the hole injection layer or the hole transport layer has a function of blocking electron transport, these layers may also serve as an electron blocking layer.

  The hole injection layer can be provided between the anode and the hole transport layer or between the anode and the light emitting layer. The hole injection layer material constituting the hole injection layer is not particularly limited, and a known material can be appropriately used. For example, a phenylamine-based, starburst-amine-based, phthalocyanine-based, hydrazone derivative, carbazole derivative, Examples include triazole derivatives, imidazole derivatives, oxadiazole derivatives having an amino group, oxides such as vanadium oxide, tantalum oxide, tungsten oxide, molybdenum oxide, ruthenium oxide, and aluminum oxide, amorphous carbon, polyaniline, and polythiophene derivatives.

  The hole transport layer material constituting the hole transport layer is not particularly limited. For example, N, N′-diphenyl-N, N′-di (3-methylphenyl) 4,4′-diaminobiphenyl (TPD) , NPB (4,4′-bis [N- (1-naphthyl) -N-phenylamino] biphenyl), etc., polyvinylcarbazole or derivatives thereof, polysilane or derivatives thereof, aromatic in side chain or main chain Polysiloxane derivative having amine, pyrazoline derivative, arylamine derivative, stilbene derivative, triphenyldiamine derivative, polyaniline or derivative thereof, polythiophene or derivative thereof, polyarylamine or derivative thereof, polypyrrole or derivative thereof, poly (p-phenylene vinylene) Down) or a derivative thereof, or a poly (2,5-thienylene vinylene) or derivatives thereof.

  Examples of the layer that can be provided between the cathode and the light emitting layer include an electron injection layer, an electron transport layer, and a hole blocking layer. When both the electron injection layer and the electron transport layer are provided, the layer close to the cathode is the electron injection layer, and the layer close to the light emitting layer is the electron transport layer. In addition, when the electron injection layer or the electron transport layer has a function of blocking hole transport, these layers may also serve as the hole blocking layer.

  Depending on the type of the light emitting layer, the electron injection layer may be an alkali metal or alkaline earth metal, an alloy containing one or more of the above metals, or an oxide, halide and carbonate of the metal, or a mixture of the above substances. Etc.

  The electron transporting material constituting the electron transporting layer is not particularly limited, and known materials can be used. For example, oxadiazole derivatives, anthraquinodimethane or derivatives thereof, benzoquinone or derivatives thereof, naphthoquinone or derivatives thereof, anthraquinone or Derivatives thereof, tetracyanoanthraquinodimethane 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, poly Examples include fluorene or a derivative thereof.

More specifically, the organic EL device can have any of the following layer configurations:
a) Anode / hole injection layer / hole transport layer / light emitting layer / electron transport layer / electron injection layer / cathode
b) Anode / hole injection layer / hole transport layer / light emitting layer / electron transport layer / cathode
c) Anode / hole injection layer / hole transport layer / light emitting layer / electron injection layer / cathode
d) Anode / hole injection layer / hole transport layer / light emitting layer / cathode
e) Anode / hole injection layer / light emitting layer / electron transport layer / electron injection layer / cathode
f) Anode / hole injection layer / light emitting layer / electron transport layer / cathode
g) Anode / hole injection layer / light emitting layer / electron injection layer / cathode
h) Anode / hole injection layer / light emitting layer / cathode
i) Anode / hole transport layer / light emitting layer / electron transport layer / electron injection layer / cathode
j) Anode / hole transport layer / light emitting layer / electron transport layer / cathode
k) Anode / hole transport layer / light emitting layer / electron injection layer / cathode
l) Anode / hole transport layer / light emitting layer / cathode
m) Anode / light-emitting layer / electron transport layer / electron injection layer / cathode
n) Anode / light emitting layer / electron transport layer / cathode
o) Anode / light emitting layer / electron injection layer / cathode
p) Anode / light-emitting layer / cathode (where / indicates that each layer is laminated adjacently)

  The organic EL device that can be manufactured according to the present invention is a device in which a plurality of pixels composed of organic EL elements are mounted as described above. Regarding the installation of electrical wiring, driving means, etc., various modes in the manufacture of a normal organic EL device can be adopted.

  The organic EL device that can be produced according to the present invention can be used as a backlight for a planar light source, a segment display device, a dot matrix display device, and a liquid crystal display device.

  In order to obtain planar light emission using an organic EL device, the planar anode and cathode may be arranged so as to overlap each other. In addition, in order to obtain pattern-like light emission, a method of installing a mask provided with a pattern-like window on the surface of the planar light-emitting element, an organic material layer of a non-light-emitting portion is formed extremely thick and substantially non- There are a method of emitting light and a method of forming either one of the anode or the cathode or both electrodes in a pattern. By forming a pattern by any of these methods and arranging several electrodes so that they can be turned on and off independently, a segment type display device capable of displaying numbers, letters, simple symbols, and the like can be obtained. Furthermore, in order to obtain a dot matrix element, a passive matrix substrate in which anodes and cathodes are both formed in stripes and arranged so as to be orthogonal to each other, or an active matrix substrate in which thin film transistors are arranged and controlled in units of pixels is used. That's fine. Furthermore, partial color display and multi-color display can be performed by separately applying light emitting materials having different emission colors or using a color filter or a fluorescence conversion filter. These display elements can be used as display devices for computers, televisions, mobile terminals, mobile phones, car navigation systems, video camera viewfinders, and the like.

  Furthermore, the planar light-emitting device is self-luminous and thin, and can be suitably used as a planar light source for a backlight of a liquid crystal display device or a planar illumination light source. If a flexible substrate is used, it can be used as a curved light source or display device.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, unless it exceeds the summary of this invention, it is not limited to a following example.

Example 1
The organic EL element substrate 1 shown in the above-described embodiment of the present invention was prepared. The reference numerals in the following description are the same as those in the above-described embodiment.

Plate member: Made of polyimide resin
Shape of plate member (see Fig. 4-1)
Constriction (minimum thickness t of the constriction t: 6 μm)
Cross-sectional shape: Arrangement interval D of angle-shaped plate members having apexes near the center line in the film thickness direction D: 360 μm
Pixel electrode arrangement interval L: 180 μm
Partition spacing: 60 μm

As the pixel electrode 41, an anode is formed by an ITO electrode. When this substrate was subjected to oxygen plasma treatment (3 Pa, 30 W, 30 SCCM, 3 minutes) and CF ₄ plasma treatment (20 Pa, 20 W, 20 SCCM, 2 minutes) using an RIE apparatus (SAMCO, RIE-200L). The partition wall 43 and the plate-like member 44 were selectively subjected to a liquid repellent treatment. In addition, the pixel electrode 41 and the pixel regulation layer 42 are in a lyophilic state.

A nozzle printing device (NP-300G, manufactured by Dainippon Screen Co., Ltd.) is used on the pixel electrode 41 (anode) in the partition area 41b. C. An ink prepared by adding 50% of CLEVIOS ^™ P CH8000 manufactured by Starck, 40% of water, and 10% of ethylene glycol was applied in a liquid column. While continuously ejecting ink from the nozzles of the nozzle printing apparatus, the nozzles are moved in the direction parallel to the partition walls 43 through the pixel electrodes 41, and the plurality of pixel electrodes 41 forming a line on the substrate Ink was applied to the surface.
A cross-sectional view immediately after ink application (before drying) based on visual recognition is shown in FIG. In addition, FIG. 7-2 shows a cross-sectional view after drying the ink based on the measurement results of the visual and palpation type step meters.
As shown in FIG. 7A, immediately after ink application, the ink was applied intermittently and continuously on the pixel electrode 41 and the plate-like member 44, but when this substrate was left in the atmosphere, The ink applied on the partition walls uniformly dropped into the partition area. Thereafter, the solvent was evaporated and dried, so that a uniform layer with small unevenness between pixels and unevenness within pixels could be formed as shown in FIG.
When the matrix portion was enlarged and visually confirmed from the upper surface, no unpainted portion was seen on each pixel electrode 41, and it was confirmed that the film was satisfactorily formed on the pixel electrode 41.
Moreover, when the cross-sectional shape of the formed layer was evaluated with a stylus step meter (P-16 + manufactured by KLA-Tencor Corporation), it was confirmed that a layer having good flatness was formed. .

  Thus, by applying ink with a nozzle printing apparatus, drying and baking, it was possible to form a hole injection layer having no flatness and good flatness. An organic EL element can be manufactured by forming a light emitting layer on the hole injection layer in the same manner, and forming a cathode on the light emitting layer using a vacuum deposition method or the like.

(Comparative Example 1)
Instead of the organic EL element substrate 1, the organic EL element substrate 2 not provided with the plate-like member 44 is used. The other conditions are the same as in Example 1 described above. went. The organic EL element substrate 2 is the same as the organic EL element substrate 1 except that the plate member 44 is not provided.
A cross-sectional view immediately after ink application based on visual recognition (before drying) is shown in FIG. Further, FIG. 9-2 shows a cross-sectional view after drying the ink based on the measurement results of the visual and palpation type step gauge.
When the matrix portion is enlarged and visually confirmed from the upper surface of the substrate immediately after the ink application, the force that the ink tries to gather due to the surface tension works, and the amount of the ink is clearly biased in the direction parallel to the partition wall 43. confirmed. Also, a clear bias in the film thickness was confirmed from the result of measuring the cross-sectional shape of the layer formed after drying the ink with a stylus type step gauge (P-16 + manufactured by KLA-Tencor Corporation).

(Comparative Example 2)
Instead of the substrate having the stripe-shaped partition wall, the organic EL element substrate 3 having the box-shaped partition wall, which is generally used in an ink jet method, is used. Ink was applied on the substrate.
A schematic cross-sectional view immediately after ink application based on visual recognition (before drying) is shown in FIG. In addition, FIG. 10-2 shows a schematic cross-sectional view after ink drying based on the measurement results of the visual and palpation type step meters.
When the matrix portion was enlarged and visually confirmed from the upper surface of the substrate immediately after the ink application, it was confirmed that the ink continuously applied on the partition walls existing in the scanning direction among the box-shaped partition walls was unevenly separated on the partition walls. It was.
Moreover, when the cross-sectional shape of the layer formed after ink drying was measured with a stylus type step gauge (P-16 + manufactured by KLA-Tencor Corporation), there was a clear film thickness distribution in the film thickness in the partitioned region. It was confirmed. Also, it was confirmed by visual observation that there was unevenness between the divided areas.

  The organic EL element substrate of the present invention is suitable for producing an organic EL element by applying a liquid column such as a nozzle printing method. By using the substrate, it is possible to obtain a high-quality organic EL element and an organic EL device having the organic EL element with small coating unevenness, which is extremely useful industrially.

DESCRIPTION OF SYMBOLS 1 Organic EL element substrate 20 Nozzle 21 Triple nozzle 30 Support substrate 40 Matrix part 41 Pixel electrode 41a Pixel electrode row 41b Partition area 42 Pixel regulation layer 43 Partition 44, 45, 46, 47, 48, 49 (Ink flow prevention For plate) 44a, 45a, 46a, 47a, 48a, 49a Constriction 44b, 45b, 46b, 47b, 48b, 49b Cross section 51 Ink (before drying)
52 Ink (after drying)
D arrangement interval of plate-like member L arrangement interval of pixel electrode t minimum plate thickness of constriction in plate-like member Dd transport direction of substrate for organic EL element Ip nozzle trajectory N _R nozzle (for red ink ejection)
_NG nozzle (for discharging green ink)
N _B nozzle (for blue ink ejection)
Nm Nozzle movement direction Nm _{1 to} Nm ₃ Nozzle movement direction P _{1 to} P ₄ positions

Claims (7)

A plurality of partition walls arranged in parallel on the support substrate;
A plurality of ink flow preventing plate-like members arranged in a direction intersecting the plurality of partition walls;
An organic EL element substrate having the partition and at least one or more pixel electrodes arranged in a region partitioned by the plate-like member,
The plate-like member is an organic EL element substrate characterized in that both end portions thereof are arranged in contact with the partition wall and have a constriction due to a decrease in thickness from both end portions toward the central portion.   The organic EL element substrate according to claim 1, wherein the pixel electrodes are arranged at regular intervals in a longitudinal direction of the partition wall.   The organic EL element substrate according to claim 2, wherein an arrangement interval D in the longitudinal direction of the partition walls of the plate-like member is 2 to 10 times the arrangement interval L of the pixel electrodes. 4. The organic EL element substrate according to claim 2, wherein the minimum thickness t of the constriction in the plate-like member and the arrangement interval L of the pixel electrodes satisfy the following formula (1). 5.

L / 60 ≦ t ≦ L / 15 (1)
  An ink containing an organic EL material is applied between the two partition walls of the organic EL element substrate according to any one of claims 1 to 4 along the longitudinal direction of the partition walls by liquid column application, and dried. A method for producing an organic EL layer, comprising obtaining an organic EL layer.   The organic EL element which has an organic EL layer obtained by the manufacturing method of Claim 5.   An ink flow prevention plate-like member used by placing both end portions in contact with two partition walls between two parallel partition walls arranged on a substrate, and directed from the both end portions toward the central portion. A plate-like member for preventing ink flow, which has a constriction due to a decrease in thickness.

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