WO2010100922A1 - Organic el display panel and method for manufacturing same - Google Patents

Abstract

Provided is an organic EL display panel which has: a substrate having an element arrangement region wherein organic EL elements are arranged in matrix and an auxiliary region composed of one or more auxiliary jetting regions; a bank which is disposed on the substrate and partitions between the auxiliary region and the element arrangement region; and a linear bank which is disposed on the substrate and defines two or more linear regions parallel to each other in the element arrangement region. In the linear region, the organic EL elements are arranged in rows, the auxiliary region is adjacent only to the edge portion of the linear region in the line direction, the length of the auxiliary jetting region in the direction perpendicular to the line direction is longer than the length of the linear region in the direction perpendicular to the line direction.

Description

Organic EL display panel and manufacturing method thereof

The present invention relates to an organic EL display panel and a manufacturing method thereof.

The organic EL display panel has an organic EL element including an anode and a cathode, and an organic light-emitting layer arranged between the electrodes and emitting electroluminescence. The material of the organic light emitting layer that emits electroluminescence can be broadly classified into a combination of a low molecular organic compound (host material and dopant material) and a high molecular organic compound. Examples of the polymer organic compound that emits electroluminescence include polyphenylene vinylene called PPV and derivatives thereof.

Organic light-emitting layers made of high molecular organic compounds can be driven at a relatively low voltage, consume less power, and are easy to deal with a large display panel. An organic light emitting layer made of a high molecular organic compound can be produced by a coating method. Therefore, the productivity of the polymer organic EL display is significantly higher than that of the low molecular organic EL display using the vacuum process.

When the organic light emitting layer is formed by a coating method, an ink containing the material of the organic light emitting layer is applied in a region defined by the barrier (bank) on the panel and dried. In order to prevent color mixing in the organic EL display panel, the ink that is the material of the light emitting layer must be accurately applied in the region defined by the bank on the panel. Examples of such a coating method include an inkjet method in which coating is performed by discharging ink. In the ink jet method, an ink jet head having a plurality of nozzles for discharging ink is usually used.

When the inkjet head is not used, the dried ink may adhere to the nozzle tip or inside. If dry ink adheres to the tip of the nozzle or the like, the nozzle is clogged, and even if the nozzle no longer ejects ink or the ink is ejected, the flying direction and the ejection amount are not stable, and the ink landing accuracy deteriorates. Therefore, immediately after the start of ink ejection, the ink landing accuracy is low, and a desired amount of ink cannot be accurately applied to a desired region.

For this reason, in order to improve the ink landing accuracy, a method is known in which ink is ejected (preliminary ejection) outside the panel before the ink is actually applied to the panel (for example, Patent Document 1 and Patent Document). 2).

However, as disclosed in Patent Document 1 and Patent Document 2, when preliminary ejection is performed outside the panel, after preliminary ejection, the inkjet head is moved to the panel while the ink jet head is moved to the front end or inside of the nozzle. The dried ink will adhere again. For this reason, before the ink is applied to the panel, the ink landing accuracy deteriorates, and there is a problem that the ink cannot be accurately applied to a desired position on the panel.

In order to solve such a problem, a technique for providing an area for preliminary ejection on a panel is known (see, for example, Patent Documents 3 to 6). FIG. 1 is a plan view of a display panel disclosed in Patent Document 3. FIG. As shown in FIG. 1, the display panel described in Patent Document 3 surrounds a bank 30 that defines a region 10 (hereinafter also referred to as “element array region 1”) in which pixels are disposed, and the element array region 10. Thus, the spare area 20 is provided. The spare area 20 is defined by the bank 40.

In the method described in Patent Document 3, first, ink is ejected from the nozzles of the inkjet head on the preliminary region 20 to perform preliminary ejection. Thereafter, the ink ejection is temporarily stopped, and the ink jet head is moved to the element array region 10. Then, ink ejection is started again from the nozzles, and ink is applied to a desired region (element array region 1) while scanning the inkjet head. Further, the display panel shown in FIG. 1 is characterized in that the width of the bank 30 that defines the element arrangement area is wide in order to prevent ink from entering the element arrangement area 1 from the spare area 20.

FIG. 2 is a perspective view of the plasma display panel described in Patent Documents 4 and 5 before the light emitting layer is formed. As shown in FIG. 2, the plasma display panel described in Patent Document 4 and Patent Document 5 includes an element array region 10 in which subpixels 11 are arrayed and a spare region 20. The spare area 20 has a plurality of spare ejection areas 23 defined by the banks 21. The width of the preliminary ejection area 23 is the same as the width 11 of the sub-pixel.

As shown in FIG. 2, in the manufacturing processes of the plasma display panels of Patent Documents 4 and 5, first, a phosphor paste, which is a dispersion solution of inorganic particles, is applied to the preliminary region 20, and the phosphor paste is discharged from each nozzle. Stabilize the amount. This makes it possible to apply a uniform amount of phosphor paste in each subpixel 11 of the element array region 10.

Thus, by providing the area for preliminary ejection on the display panel, the time between the preliminary ejection and the ink application to the element array area can be shortened.

In addition, a display panel is known in which a non-light emitting area in which dummy pixels are arranged is provided around a light emitting area in which pixels are arranged (see, for example, Patent Documents 7 to 9). By applying ink not only to the pixels in the light emitting region but also to the dummy pixels, it is possible to reduce variations in the drying speed of the ink applied to the pixels in the light emitting region.

JP 2002-264366 A JP 2008-108570 A JP 2007-09431 A US Patent Application Publication No. 2005/0116643 US Patent Application Publication No. 2008/0003915 JP 2008-153126 A US Patent Application Publication No. 2002/0064966 JP 2002-222695 A JP 2003-233330 A

However, when the spare area surrounds the element array area as in the display panel shown in FIG. 1, the ratio of the spare area (non-light emitting area) in the entire panel increases, and the element array area (light emitting area) in the organic EL display panel. The ratio of will decrease.

In addition, as disclosed in FIG. 2, when the preliminary ejection area is finely defined by the banks, the number of banks included in the preliminary area increases. If there are many banks in the spare area, ink may land on the bank in the spare area and remain on the bank during preliminary ejection with low ink landing accuracy. When ink having a particularly high viscosity is ejected by the ink jet method, the flying direction of the ink tends to vary, and the ink tends to land on the bank. The ink remaining on the bank becomes particles when dried, which may cause display defects.

An object of the present invention is to provide a method for manufacturing an organic EL display panel capable of achieving both improvement in ink landing accuracy, improvement in the ratio of the light emitting region, and suppression of defects.

The first of the present invention relates to the following organic EL display panel.
[1] A substrate having an element arrangement region in which organic EL elements are arranged in a matrix and a spare region composed of one or more preliminary ejection regions, and a substrate disposed on the substrate, the spare region, An organic EL display panel comprising: a bank that divides an element array region; and a line bank that is disposed on the substrate and defines two or more parallel line regions in the element array region, The organic EL elements are arranged in a line in the line-shaped region, and the preliminary region is adjacent only to the end of the line-shaped region in the line direction and is perpendicular to the line direction of the preliminary discharge region. The length of the direction is an organic EL display panel that is longer than the length of the linear region in the direction perpendicular to the line direction.
[2] A substrate having an element arrangement area in which organic EL elements are arranged in a matrix and a spare area composed of a preliminary ejection area; and a substrate disposed on the substrate, wherein the spare area and the element arrangement area are An organic EL display panel having a partitioning bank and a line bank disposed on the substrate and defining two or more parallel line regions in the element array region, wherein the organic EL display panel includes The organic EL elements are arranged in a line, the preliminary area is adjacent only to the side of the line area in the line direction, and the length of the preliminary discharge area in the direction perpendicular to the line direction is An organic EL display panel that is at least twice the length of the linear region in the direction perpendicular to the line direction.

2nd of this invention is related with the manufacturing method of the organic electroluminescent display panel shown below.
[3] A substrate having an element arrangement area in which pixel electrodes are arranged in a matrix and a spare area composed of one or more preliminary ejection areas, and the spare area and the element arrangement area arranged on the substrate. And a bank that is arranged on the substrate and defines two or more parallel line-shaped areas in the element array area, the base panel comprising: The organic EL elements are arranged in a row, and the preliminary region is adjacent to only the end of the line region in the line direction, and is perpendicular to the line direction of the line region of the preliminary discharge region. The step of preparing the base panel is longer than the length of the linear region in the direction perpendicular to the line direction, and the ink having two or more nozzles and containing the organic layer material is supplied. An inkjet head to be disposed on the spare area, a step of ejecting the ink from the nozzles on the spare area at regular intervals, and landing ink in the spare ejection area; The ink jet head is moved from the spare area to the element array area while the discharge is maintained, and the ink jet head is moved along the line direction to apply the ink to the line area. And a method of manufacturing an organic EL display panel.
[4] A substrate having an element arrangement area in which pixel electrodes are arranged in a matrix and a spare area composed of a preliminary ejection area, and a substrate disposed on the substrate, and dividing the spare area and the element arrangement area. A base panel having a bank and a line bank that defines two or more parallel line regions in the element arrangement region and is disposed on the substrate, wherein the line region includes: The pixel electrodes are arranged in a row, the spare area is adjacent to only the side of the line area in the line direction, and the length of the spare discharge area in the direction perpendicular to the line direction is the line shape. A step of preparing a base panel that is at least twice the length of the region in the direction perpendicular to the line direction; and an inkjet head having two or more nozzles and supplied with ink containing an organic layer material. Are disposed on the spare area, the ink is ejected from the nozzle on the spare area, the ink is landed in the spare area, and the ink jet head is disposed from the spare area. A method of manufacturing an organic EL display panel, comprising: moving to an element array region; and moving the inkjet head along a direction perpendicular to the line direction to apply the ink to the line region.

According to the present invention, by providing an area for preliminary ejection (preliminary area) on the panel, ink can be applied to a desired area with high accuracy, and an organic EL display panel having no color mixture can be obtained.

Also, in the present invention, the ratio of the light emitting area of the organic EL display panel can be improved by reducing the spare area which is a non-light emitting area to the minimum necessary.

Further, according to the present invention, the spare area does not have a bank, or the spare area has a small number of banks, and therefore, there is a low possibility that the ink ejected by the preliminary ejection will land on the bank. For this reason, there is a low possibility that particles generated by drying the ink remaining on the bank will be a defect of the organic EL display panel.

Plan view of a conventional organic EL display panel described in Patent Document 3 The perspective view of the conventional organic electroluminescent display panel described in patent document 4 and 5 Plan view of base panel of Embodiment 1 Sectional drawing of the base panel of Embodiment 1 The figure which shows the manufacturing method of the organic electroluminescent display panel of Embodiment 1. FIG. The figure which shows the manufacturing method of the organic electroluminescent display panel of Embodiment 1. FIG. The figure which shows the manufacturing method of the organic electroluminescent display panel of Embodiment 1. FIG. The figure which shows the manufacturing method of the organic electroluminescent display panel of Embodiment 1. FIG. Plan view of organic EL display panel of Embodiment 1 Plan view of organic EL display panel of Embodiment 1 Plan view of base panel of embodiment 2 Top view of base panel Plan view of base panel of Embodiment 3 The figure which shows the manufacturing method of the organic electroluminescent display panel of Embodiment 3. FIG. Plan view of base panel according to Embodiment 4 The figure which shows the manufacturing method of the organic electroluminescent display panel of Embodiment 4. FIG. The figure which shows the manufacturing method of the organic electroluminescent display panel of Embodiment 4. FIG. The figure which shows the manufacturing method of the organic electroluminescent display panel of Embodiment 4. FIG. Plan view of organic EL display panel of Embodiment 4 Plan view of organic EL display panel of Embodiment 4

1. Manufacturing method of organic EL display panel The manufacturing method of the organic EL display panel according to the present invention includes: 1) preparing a base panel having a preliminary area composed of preliminary ejection areas and an element arrangement area having a plurality of line-shaped areas; 1 step, 2) a second step in which an ink jet head having two or more nozzles and supplied with ink containing the material of the organic layer is disposed on the preliminary area, and 3) from the nozzle in the preliminary ejection area A third step of ejecting ink (preliminary ejection), 4) a fourth step of moving the ink jet head from the preliminary region to the element array region, and 5) applying an ink to the linear region to form an organic layer. Steps.

In the fifth step, the method of applying ink to the line-shaped region includes a method of moving the inkjet head along the line direction of the line-shaped region (hereinafter also referred to as “vertical coating”), a line direction of the line-shaped region, There is a method of moving along a vertical direction (hereinafter also referred to as “horizontal coating”). In the present invention, either vertical coating or horizontal coating may be adopted as a method of applying ink to the line-shaped region.

Further, the present invention is characterized by preventing color mixing and defects while increasing the ratio of the light emitting region by devising the structure of the base panel prepared in the first step. Each step will be described below.

1) In the first step, prepare the base panel. The base panel means an organic EL display panel before the organic layer is formed. The base panel includes a substrate on which pixel electrodes are arranged and a bank.

The substrate has a spare area and an element arrangement area on its surface. Pixel electrodes are arranged in a matrix in the element array region. The element arrangement region is a region that becomes a light emitting region in the organic EL display panel. The pixel electrode is formed on the substrate by, for example, sputtering.

The preliminary area is an area for preliminary ejection described later, and is a non-light emitting area. Therefore, the spare area does not have a pixel electrode. The present invention is characterized by the position and structure of the spare area. The position and structure of the spare area will be described later.

The bank is a barrier that is disposed on the substrate and defines a layer to be applied and formed. The base panel has a bank (hereinafter also referred to as “boundary bank”) that is divided into an element array region and a spare region, and a line bank that is defined as two or more line regions in the element array region. It is preferable that the bank has low wettability because it defines a region where ink is applied.

The line bank defines a plurality of parallel line areas in the element array area (see FIG. 3). Therefore, the element array region has a plurality of line-shaped regions. The line-shaped region is also referred to as an application region because it is a region where ink containing the organic layer material is applied. In each line-shaped region, a plurality of pixel electrodes are arranged in rows.

Further, a liquid repellent self-assembled monolayer (SAM) may be used instead of the bank (see Embodiment 3). Thus, when a liquid-repellent self-assembled monolayer is used instead of a bank, the self-assembled monolayer is a glass or silicon oxide (SiO ₂ ) film, a metal film, a metal oxide film, or the like. It is preferable to be disposed on the top. As a material for the self-assembled monolayer, a material having a silane coupling structure at the end of the organic material is preferable. Since the silane coupling bond can be cut by irradiation with light such as ultraviolet rays, the self-assembled monolayer can be patterned by irradiation with light using a photomask.

Next, the structure and location of the spare area will be described. The spare area is composed of one or more preliminary ejection areas. The preliminary ejection area is an area where ink ejected by preliminary ejection described later lands.

The arrangement position of the spare area is appropriately selected according to the ink application method (vertical coating or horizontal coating) employed in the present invention. Hereinafter, the arrangement position of the spare area will be described separately for a) when vertical coating is used and b) when horizontal coating is used.

a) When vertical coating is adopted (see Embodiment 1)
When the vertical coating is adopted, the spare area is adjacent to only the end of the line-shaped area in the line direction, and is not adjacent to the side of the line-shaped area in the line direction (see FIG. 3). In this case, the spare region has a major axis along a direction perpendicular to the line direction of the linear region (hereinafter also simply referred to as “line direction”) and a minor axis along the line direction. The long axis of the spare region is longer than the length of the element array region in the direction perpendicular to the line direction (see FIG. 3).

Further, when vertical coating is adopted, the preliminary area may consist of one preliminary ejection area, or may consist of two or more preliminary ejection areas. When the spare area includes one spare ejection area, the spare area does not have a bank (Embodiment 1). On the other hand, when the spare area includes two or more spare ejection areas, the spare area has a bank that defines the spare ejection area (see the second embodiment). The bank included in the spare area has a long axis parallel to the line direction (see Embodiment 2). In any case, the number of banks included in the spare region is smaller than the number of line banks included in the element array region (see FIG. 11).

b) When horizontal coating is adopted (see Embodiment 4)
When horizontal coating is adopted, the spare area is adjacent to only the side portion of the line-shaped area in the line direction, and is not adjacent to the end of the line-shaped area in the line direction (see FIG. 15). In this case, the spare region has a major axis along the line direction and a minor axis along a direction perpendicular to the line direction. Further, when horizontal coating is adopted, it is preferable that the preliminary area is composed of one preliminary ejection area.

As described above, in the organic EL display panel of the present invention, the spare area is the same as that of the conventional display panel regardless of whether vertical coating or horizontal coating is employed (FIG. 1). Reference) Does not enclose the element array region. Thereby, the ratio of the reserve area | region which is a non-light-emission area | region in an organic electroluminescent display panel can be made small, and the ratio of the element arrangement | sequence area | region which is a light emission area | region can be enlarged.

2) In the second step, the inkjet head is placed on the spare area. The ink jet head has a plurality of nozzles. Ink containing an organic layer material is supplied to the inkjet head. The ink preferably contains a polymer organic EL material. The polymer organic EL material is preferably selected as appropriate so that a desired color (R, G, B) is generated.

As described above, the position of the spare area differs depending on whether vertical coating or horizontal coating is used. For this reason, the position where the inkjet head is arranged on the spare area in the second step is also different between the case where the vertical coating is adopted and the case where the horizontal coating is adopted.

The number of inkjet heads arranged on the spare area may be one (see FIG. 5A), or two or more. By using two or more inkjet heads, a wider area can be applied at once. If three ink jet heads are stacked and R, G, or B ink is supplied to each ink jet head, it becomes possible to apply R, G, and B inks simultaneously. Ink can be applied to the line-shaped region.

3) In the third step, ink is ejected from the nozzles (preliminary ejection) on the preliminary area, and the ink is landed in the preliminary ejection area. The preliminary discharge is preferably continued until the clogging of the nozzle is eliminated and the meniscus vibration period is stabilized. Nozzle clogging is eliminated and the meniscus vibration cycle is stabilized, so that the ink ejection amount and flight direction are stabilized, and the ink landing accuracy is stabilized. The meniscus vibration period obtained by the preliminary discharge is preferably maintained up to the fifth step.
The preliminary discharge time is usually 0.01 to 5 s. In addition, the amount of ink ejected by one nozzle at a time (the amount of ink droplet ejected by the nozzle) is usually 3 pl to 20 pl.

In the third step, it is preferable that the ink is landed on the preliminary ejection region while moving the ink jet head in the element array region direction (see FIG. 6A). By moving the inkjet head in the direction of the element arrangement region during the preliminary ejection, the inkjet moving speed in the fourth step and the fifth step described later is stabilized.

In the present invention, the moving direction of the inkjet head in the third step to the fifth step is the same. Therefore, when vertical coating is adopted, the inkjet head always moves along the line direction; when horizontal coating is adopted, the inkjet head always moves along a direction perpendicular to the line direction. By unifying the moving direction of the inkjet head in this way, the scanning of the inkjet head is stabilized.

In order to move the inkjet head, the inkjet head itself may be moved, the base panel may be transported, or both may be moved.

Thus, by performing preliminary discharge until the ink discharge amount and the flight direction are stabilized, the ink landing accuracy is improved, and the ink can be accurately applied to the line-shaped region in the fifth step described later. . Here, “the landing accuracy is stable” means that the flying direction and the discharge amount of the ink are stabilized.

Further, as described above, since the number of banks included in the spare area is small, there is little possibility that the ink flying during the preliminary ejection in which the ink flying direction is unstable will land on the bank and remain on the bank. Thereby, generation | occurrence | production of the particle | grains causing the defect of an organic electroluminescence display panel can be prevented.

4) In the fourth step, the inkjet head is moved from the spare area to the element array area. The movement of the inkjet head from the preliminary region to the element array region is preferably performed while maintaining a stable meniscus vibration period obtained by the preliminary ejection. In order to move the ink jet head from the spare area to the element array area while maintaining a stable meniscus vibration period, the actuator of each nozzle may be driven even during the movement. In this way, the landing accuracy obtained in the preliminary region can be maintained by maintaining the stable meniscus vibration period obtained by the preliminary ejection even during the movement of the inkjet head from the preliminary region to the element array region. Can do.

In order to move the inkjet head, the inkjet head itself may be moved, the base panel may be transported, or both may be moved. The moving speed of the ink jet head relative to the base panel is preferably 1 mm / s to 100 mm / s.

Also, when the inkjet head is moved during preliminary ejection in the third step, it is preferable that the movement speed of the inkjet head in the fourth step is the same as the movement speed of the inkjet head in the third step.

5) In the fifth step, ink is applied to the line-shaped region with an inkjet head. In order to apply ink to the line-shaped region with the inkjet head, the ink ejected from the nozzles may be landed on the line-shaped region while scanning the element array region with the inkjet head. The scanning direction of the inkjet head differs depending on whether vertical coating or horizontal coating is employed. The organic layer is formed by drying the applied ink. The moving speed of the ink jet head in the fifth step is preferably the same as the moving speed of the ink jet head in the fourth step.

Furthermore, an organic EL display panel may be formed by forming a counter electrode on the organic layer by sputtering or the like.

As described above, according to the present invention, ink can be accurately applied to the line-shaped region by preliminary ejection, and an organic EL display panel without color mixture can be obtained. Further, in the present invention, there is little possibility that ink remains on the bank in the spare area and causes particles. For this reason, according to the present invention, an organic EL display panel with few defects is provided.

2. About the organic EL display panel of this invention Next, the organic EL display manufactured by the manufacturing method of the organic EL display panel mentioned above is demonstrated. The organic EL display panel of the present invention includes a substrate, a bank disposed on the substrate, and organic EL elements disposed in a matrix on the substrate.

The organic EL display panel of the present invention may be a passive matrix type or an active matrix type. Furthermore, the organic EL display panel of the present invention may be a bottom emission type (a type in which light is extracted through a pixel electrode and a substrate) or a top emission type (a type in which light is extracted through a counter electrode and a sealing film). .

About the substrate The substrate has an element array region and a spare region. In the element array region, organic EL elements are arranged in a matrix. The element array region is defined by a line bank described later and has a plurality of line regions parallel to each other. Organic EL elements are arranged in a line in the line-shaped region. Further, in the element arrangement region, the substrate may incorporate a driving TFT for driving the organic EL element.

The spare area is composed of one or more preliminary ejection areas. In the preliminary ejection region, no organic EL element is disposed, and residues of organic light emitting materials that emit red, green, and blue are mixed.

The material of the substrate differs depending on whether the organic EL display panel of the present invention is a bottom emission type or a top emission type. Since the substrate is required to be transparent when the organic EL display panel is a bottom emission type, examples of the substrate material include transparent materials such as PET (polyethylene terephthalate), PEN (polyethylene naphthalate), and PI (polyimide). Resin and glass are included. On the other hand, when the organic EL display panel is a top emission type, the substrate does not need to be transparent, and therefore the material of the substrate is arbitrary as long as it has insulating properties.

About Banks A bank is a barrier that defines a layer that is disposed on a substrate and applied. The bank height (distance from the substrate surface to the top of the bank) is preferably 0.5 μm to 2 μm.

The organic EL display panel of the present invention has a bank that divides the substrate surface into a spare area and an element array area, and a line bank that defines two or more line-shaped areas in the element array area.

The line bank defines a plurality of line areas in the element array area (see FIG. 3). Therefore, the element array region has a plurality of line-shaped regions. The width of the line bank is 10 μm to 50 μm, for example, about 30 μm.

As described above, it is preferable that the bank has low wettability because it defines a region where ink is applied. In order to reduce the wettability of the bank, the bank may be plasma-treated with fluorine gas, or the bank material may be a fluorine-containing resin. Fluorine-containing resin should just have a fluorine atom in at least one part repeating unit among the polymer repeating units.

When the bank is plasma-treated with fluorine gas, the bank material is preferably polyimide or acrylic resin. Examples of the fluorine-containing resin include a fluorinated polyimide resin, a fluorinated polymethacrylic resin, and a fluorine-containing phenol / novolak resin.

Regarding the organic EL elements As described above, the organic EL elements are arranged in a line in each linear region of the element arrangement region. Each of the organic EL elements functions as a sub-pixel that emits light of any one color of red, green, and blue. All the organic EL elements arranged in the same linear region emit light of the same color. The organic EL element has a pixel electrode disposed on a substrate, an organic layer disposed on the pixel electrode, and a counter electrode disposed on the organic layer.

The pixel electrode is a conductive member disposed on the substrate. The pixel electrode normally functions as an anode, but may function as a cathode. When the organic EL display panel is a bottom emission type, the pixel electrode is required to be transparent. Examples of the material for the pixel electrode include ITO (Indium Tin Oxide), IZO (Indium Zinc Oxide), and tin oxide. included. On the other hand, when the organic EL display panel is a top emission type, since the pixel electrode is required to have light reflectivity, examples of the material of the pixel electrode include APC alloy (silver, palladium, copper alloy) and ARA (silver, rubidium). , Gold alloy), MoCr (molybdenum and chromium alloy), NiCr (nickel and chromium alloy), and the like. The thickness of the pixel electrode is typically 100 nm to 500 nm, and can be about 150 nm.

Further, when the organic EL display panel of the present invention is a passive matrix type, a plurality of organic EL elements share one line-shaped pixel electrode. When the pixel electrode has a line shape, the line direction of the line bank and the line direction of the pixel electrode are preferably orthogonal. On the other hand, when the organic EL display panel of the present invention is an active matrix type, the pixel electrode is disposed independently for each organic EL element (see FIG. 3) and connected to the driving TFT.

The organic layer is a layer including at least an organic light emitting layer formed on the pixel electrode by a coating method. The organic layer may further include a hole injection layer, an intermediate layer, an electron transport layer, and the like. As described above, the present invention is characterized in that the organic layer is formed by a coating method. The organic layer is disposed in a region defined by the bank. That is, a line-shaped organic layer is formed in the line-shaped region. Therefore, the organic layers of the organic EL elements in the line region are connected. The thickness of the organic layer is preferably about 50 nm to 100 nm (for example, 70 nm).

The organic light emitting layer is a layer containing an organic light emitting material. The organic light emitting material contained in the organic light emitting layer may be a low molecular organic light emitting material or a polymer organic light emitting material, but is preferably a polymer organic light emitting material. This is because an organic light emitting layer containing a polymer organic light emitting material is easy to form by coating. Examples of the polymeric organic light-emitting material include polyphenylene vinylene and derivatives thereof, polyacetylene and derivatives thereof, polyphenylene and derivatives thereof, polyparaphenylene ethylene and derivatives thereof, and poly-3-hexylthiophene ( Poly-3-hexylthiophene (P3HT)) and derivatives thereof, polyfluorene (PF) and derivatives thereof, and the like.

The organic light emitting material is appropriately selected so that a desired color (red, green or blue) is generated from each sub-pixel (organic EL element). For example, a green subpixel is arranged next to the red subpixel, a blue subpixel is arranged next to the green subpixel, and a red subpixel is arranged next to the blue subpixel.

The counter electrode is a conductive member disposed on the organic layer. The counter electrode normally functions as a cathode, but may function as an anode. When the organic EL display panel of the present invention is a top emission type, examples of the material of the counter electrode include light transmissive materials such as ITO, IZO, Ba, Al, and WOx. On the other hand, when the organic EL display panel of the present invention is a bottom emission type, the material of the counter electrode is not particularly limited, and examples thereof include Ba, BaO, and Al.

Further, when the organic EL display panel is an active matrix type, all organic EL elements may share one counter electrode (see FIG. 3). This is because in the active matrix organic EL display panel, each subpixel is driven by an independent TFT. On the other hand, when the organic EL display panel is a passive matrix type, a plurality of line-shaped counter electrodes are arranged on the panel. In this case, the line bank functions as a cathode separator. The line direction of the line-shaped counter electrode is preferably orthogonal to the line direction of the line-shaped pixel electrode.

As described above, in the organic EL display panel of the present invention, the spare area which is a non-light emitting area does not surround the element arrangement area which is a light emitting area unlike the conventional display panel (see FIG. 1). Thereby, the ratio of the reserve area | region which is a non-light-emission area | region in an organic electroluminescent display panel can be made small, and the ratio of the element arrangement | sequence area | region which is a light emission area | region can be enlarged.

Embodiments of an organic EL display panel according to the present invention will be described below with reference to the drawings.

[Embodiment 1]
In the first embodiment, a method for manufacturing an organic EL display panel employing vertical coating will be described. Further, the organic EL display panel manufactured in the first embodiment is an active matrix type.

The manufacturing method of the organic EL display panel according to the first embodiment includes 1) a first step of preparing a base panel (see FIG. 3), and 2) a second step of arranging the inkjet head 120 on the spare area 107 (FIG. 5A), 3) a third step (see FIG. 6A) in which ink is ejected from the nozzle 121 on the preliminary area 107 at regular intervals, and ink is landed on the preliminary ejection area 108, and 4) at regular intervals. A fourth step (see FIG. 6B) in which the inkjet head 120 is moved from the preliminary area 107 to the element array area 105 while maintaining the ejection, and 5) a fifth step in which ink is applied to the linear area (application area) 104 ( 8A).

The present embodiment is characterized in that the inkjet head 120 is moved from the preliminary region 107 to the element array region 105 while maintaining the discharge interval of the preliminary discharge in the fourth step.

Further, in the present embodiment, the direction in which the inkjet head moves in the third step to the fifth step is the same. That is, in the present embodiment, the inkjet head is moved along the line direction. Each step will be described below.

1) In the first step, prepare the base panel. FIG. 3 is a plan view of the base panel prepared in the first step. As shown in FIG. 3, the base panel 110 includes a substrate 101, a pixel electrode 102, and banks (a boundary bank 103 and a line bank 106).

The substrate 101 has an element array region 105 and a spare region 107 on its surface. In the element array region 105, the pixel electrodes 102 are arranged in a matrix.

The line bank 106 defines a line area (application area) 104 in the element array area 105. Therefore, the element array region 105 has a plurality of line-shaped regions 104. The width 106w of the line bank 106 is preferably 10 μm to 50 μm. The line-shaped region 104 has a plurality of pixel electrodes 102 arranged in one row.

The boundary bank 103 divides the spare area 107 and the element array area 105. In the present embodiment, it is preferable that the width 103w of the boundary bank 103 is narrow. Here, the “bank width” means the length of the bottom surface of the bank in the short direction (see FIG. 4B). For example, the width 103 w of the boundary bank 103 is preferably narrower than the width (80 μm to 200 μm) of the sub-pixel of the organic EL display panel or the width 106 w of the line bank 106. More specifically, the width 103w of the boundary bank 103 is preferably 10 μm to 300 μm, and more preferably 20 μm to 50 μm. Thus, this embodiment is characterized in that the width 103w of the boundary bank 103 is relatively narrow.

4A is a cross-sectional view taken along line AA of the base panel 110 shown in FIG. 4B is an enlarged view of the square X shown in FIG. 4A. As shown in FIG. 4B, the shape of the boundary bank 103 is a forward tapered shape. The taper angle α of the boundary bank 103 is preferably 20 ° to 50 °. Further, the cross section of the boundary bank 103 may be a triangle as shown in FIG. 4C or a semicircle as shown in FIG. 4D. The boundary bank 103 preferably has liquid repellency. Specifically, the contact angle of anisole at the apex of the boundary bank 103 is preferably 30 ° to 70 °, and more preferably 40 ° to 50 °.

Next, the structure and arrangement position of the spare area 107 will be described with reference to FIG. The spare area 107 includes one spare ejection area 108. Therefore, in the present embodiment, the spare area 107 does not have a bank that divides the spare ejection area.

The spare area 107 is adjacent to only one end (upward in the drawing) of the line area 104 in the line direction. Further, if the spare region 107 is not adjacent to the side of the linear region 104 in the line direction, the spare region 107 may be arranged on both sides of the element array region 105 so as to sandwich the element array region 105. . That is, the spare area 107 may be adjacent to both ends of the line area 104 in the line direction.

Thus, in the present embodiment, the spare region 107 does not surround the element array region 105 and is adjacent only to the end of the line-shaped region 104 in the line direction. Thereby, the ratio of the non-light-emitting area (preliminary area) in the organic EL display panel can be reduced, and the ratio of the light-emitting area (element array area) can be increased.

The long axis of the spare area 107 is perpendicular to the line direction. The short axis of the spare area 107 is parallel to the line direction.

The length 107L of the spare area 107 in the direction perpendicular to the line direction (the length of the major axis of the spare area 107) is the length in the direction perpendicular to the line direction of the element array area 105 (hereinafter referred to as “the element array area 105 The width is preferably longer than 105L. In this embodiment, since the preliminary region 107 is composed of one preliminary discharge region 108, the length of the major axis of the preliminary discharge region 108 is preferably longer than the width 105L of the element array region 105. This is because, when the length 107L of the long axis of the preliminary area 107 is shorter than the width 105L of the element array area 105, there is a possibility that the ink may land on an area other than the preliminary discharge area 108 in the preliminary discharge described later. .

The length 107S of the spare area 107 in the line direction (the length of the minor axis of the spare area 107) is preferably, for example, not less than the length of the major axis of the sub-pixel of the organic EL display panel (for example, 300 μm). Similarly, the length of the short axis of the preliminary discharge region 108 is preferably 300 μm or more. This is because, when the short axis length 107S of the preliminary area 107 is less than the length of the sub-pixel, the ink may land on an area other than the preliminary ejection area 108 in the preliminary ejection described later.

2) FIG. 5A is a diagram showing the second step using a plan view of the base panel, and FIG. 5B is a diagram showing the second step using a cross-sectional view of the base panel taken along line AA in FIG. 5A. is there. As shown in FIGS. 5A and 5B, in the second step, the inkjet head 120 having two or more nozzles 121 and supplied with ink containing the organic layer material is disposed on the preliminary region 107.

As shown in FIG. 5A, in the second step, the arrangement direction of the nozzles 121 of the inkjet head 120 is arranged along a direction perpendicular to the line direction. Further, the arrangement direction of the nozzles 121 may be inclined with respect to the direction perpendicular to the line direction.

3) FIG. 6A shows the third step using a cross-sectional view of the base panel. As shown in FIG. 6A, in the third step, ink is ejected (preliminary ejection) from the nozzle 121 at regular intervals on the preliminary area 107, and ink is landed in the preliminary ejection area 108.

The discharge interval (time from one discharge to the next discharge) varies depending on the drive frequency, but is usually (range of drive frequency 1 kHz to 20 kHz) 0.05 ms to 1.0 ms.

Also, the ink jet head 120 is moved in the direction of the element array region 105 during preliminary ejection. The moving direction of the inkjet head is parallel to the line direction. By moving the inkjet head in the direction of the element arrangement region during the preliminary ejection, the inkjet moving speed in the fourth step and the fifth step described later is stabilized.

The moving speed of the inkjet head relative to the base panel is preferably 1 mm / s to 100 mm / s.

Thus, by performing preliminary ejection on the preliminary area before applying ink to the line-shaped area, nozzle clogging is eliminated, the meniscus vibration period is stabilized, and the flying direction and ejection amount of ink are stabilized. Thereby, the landing accuracy is improved, and the ink can be accurately applied to the line-shaped region in the fifth step described later. Further, as described above, the spare area 107 does not have a bank that divides the spare ejection area. For this reason, even if the ink landing accuracy in the preliminary ejection is low, all of the ejected ink is landed in the preliminary ejection region 108. For this reason, there is no possibility that the ink landed on the bank becomes particles.

4) FIG. 6B shows the fourth step using a cross-sectional view of the base panel. As shown in FIG. 6B, in the fourth step, the inkjet head 120 is moved from the preliminary region 107 to the element array region 105 while maintaining the discharge at regular intervals in the preliminary discharge.

While the ink jet head 120 is moved from the preliminary region 107 to the element array region 105, the discharge at a certain interval is maintained, so that the ink jet head 120 maintains the stable meniscus vibration period obtained by the preliminary discharge. The For this reason, it is possible to apply ink to the line-shaped region 104 while maintaining the landing accuracy of the ink obtained by the preliminary ejection (fifth step).

On the other hand, if the inkjet head 120 is moved from the spare area 107 to the element array area 105 while maintaining ejection at regular intervals, ink may remain on the top surface of the boundary bank 103. The ink remaining on the top surface of the boundary bank 103 is dried to become particles, which may cause a display panel failure.

However, in the present embodiment, since the shape of the boundary bank 103 is devised as described above, it is assumed that the inkjet head 120 is moved from the spare area 107 to the element array area 105 while maintaining ejection at regular intervals. Ink does not remain on the top surface of the boundary bank 103.

FIG. 7A is an enlarged cross-sectional view of the boundary bank 103 after the fourth step. As shown in FIG. 7A, when the inkjet head 120 is moved while maintaining ejection at regular intervals, the ink 130 is also applied to the top surface of the boundary bank 103, and the top surface of the boundary bank 103 is Ink 130 may remain temporarily.

However, as described above, in the present embodiment, the boundary bank 103 has liquid repellency, a narrow width, and a tapered shape. Therefore, the ink 130 applied to the top surface of the boundary bank 103 is an arrow. It is pulled in the direction, and is torn to the line-shaped region 104 side and the preliminary ejection region 108 side, and is divided (FIG. 7B). The force pulling the ink 130 in the direction of the arrow is further strengthened by the forward taper shape of the bank. When the ink 130 applied to the top surface of the boundary bank 103 is torn off and divided, the ink 130 slides down to the side surface of the boundary bank 103, and finally either the line-shaped region 104 or the preliminary ejection region 108. (FIG. 7C).

In this way, by adjusting the shape and liquid repellency of the boundary bank 103, even when the inkjet head is moved while maintaining the discharge at regular intervals, the ink is applied to the top surface of the boundary bank 103. Does not remain.

On the other hand, if the width of the boundary bank is 300 μm or more, the ink may remain on the top surface of the boundary bank 103. Further, when the width of the boundary bank 103 is 10 μm or less, the boundary bank 103 cannot completely divide the ink to be applied, and there is a possibility that ink is mixed in the line-shaped region 104 and the preliminary ejection region 108. . In addition, when the shape of the boundary bank is not a forward taper shape (for example, in the case of a reverse taper shape), the ink applied to the top surface of the boundary bank 103 is difficult to move to the side surface of the boundary bank 103 and There is a high risk of remaining.

5) FIG. 8A shows the fifth step using a plan view of the base panel; FIG. 8B shows the fifth step using a cross-sectional view of the base panel taken along line AA in FIG. 8A. As shown in FIGS. 8A and 8B, in the fifth step, the inkjet head 120 is moved along the line direction to apply ink to the line-shaped region. The organic layer is formed by drying the applied ink.

By repeating the third step to the fifth step, all the line-shaped regions are applied, and an organic layer is formed. Furthermore, the organic EL display panel 100 of this Embodiment as shown in FIG. 9 is manufactured by forming a counter electrode on the formed organic layer by, for example, a sputtering method.

As described above, in the present embodiment, the moving direction of the inkjet head 120 is the same in the third step to the fifth step. For this reason, the scanning of the inkjet head 120 is stabilized, and the ink can be stably applied to the line-shaped region 104.

Thus, according to the present embodiment, ink can be accurately applied to the line-shaped region, and an organic EL display panel having no color mixture can be obtained. Further, in the present invention, since no ink remains on the top surface of the boundary bank, an organic EL display panel with few defects can be provided.

Next, the organic EL display panel manufactured by the method for manufacturing the organic EL display panel of the present embodiment will be described.

FIG. 9 is a plan view of the organic EL display panel 100 of the first embodiment. FIG. 10 is a plan view of the organic EL display panel 100 from which the counter electrode 109 is omitted.

As shown in FIG. 10, the organic EL display panel 100 includes a substrate 101, a boundary bank 103, a line bank 106, and an organic EL element 140.

The substrate 101 has an element arrangement area 105 in which organic EL elements 140 are arranged in a matrix and a spare area 107 including a preliminary ejection area 108. The spare region 107 does not surround the element array region 105 and is adjacent only to the end of the line-shaped region 104 in the line direction. Further, in the spare area 107, residues of R, G, and B organic light emitting materials are mixed.

The boundary bank 103 divides the element array area 105 and the spare area 107, and the line bank 106 defines a plurality of line-shaped line areas 104 in the element array area 105. In the line-shaped region 104, organic EL elements 140 are arranged in a line.

The organic EL element 140 includes an organic EL element 140R that emits red light, an organic EL element 140G that emits green light, and an organic EL element 140B that emits blue light. The organic EL elements 140 arranged in one line-shaped region 104 emit the same light. Moreover, one pixel is comprised from the organic EL element 140R, the organic EL element 140G, and the organic EL element 140B.

As described above, in the organic EL display panel 100 according to the present embodiment, the spare area 107 does not surround the element array area 105. Therefore, the ratio of the non-light-emitting area (preliminary area) in the organic EL display panel is reduced. The ratio of (element arrangement region) can be increased.

[Embodiment 2]
In the first embodiment, a description has been given of a mode in which the spare area is composed of one preliminary ejection area. In the second embodiment, a mode in which the preliminary area is composed of a plurality of preliminary ejection areas will be described.

FIG. 11 is a plan view of the base panel 210 prepared by the method for manufacturing the organic EL display panel of the second embodiment. The base panel 210 is the same as the base panel 110 of the first embodiment except that the preliminary area 207 includes a plurality of preliminary ejection areas 208. Therefore, the same components as those of the base panel 110 are denoted by the same reference numerals and description thereof is omitted.

As shown in FIG. 11, in the base panel 210, the preliminary area 207 has a bank 203 that divides the preliminary ejection area 108. The major axis of the bank 203 is parallel to the line direction of the line bank 106.

The number of banks 203 included in the spare area 207 is smaller than the number of line banks 106 included in the element array area 105. As a result, the length 208L of each preliminary ejection region 208 in the direction perpendicular to the line direction is greater than the length 104w of the line-shaped region 104 in the direction perpendicular to the line direction (the length of the short axis of the line-shaped region 104). Also gets longer.

As described above, in this embodiment, the spare area 207 has the bank 203. For this reason, the area of the preliminary ejection region 208 per unit area of the preliminary region 207 is reduced by the area occupied by the bank 203 as compared with the preliminary region 107 of the first embodiment having no bank.

For this reason, assuming that the amount of ink landed on the preliminary discharge area in the preliminary discharge is constant, the preliminary area 107 has a unit area per unit area of the preliminary discharge area 208 as compared with the first embodiment in which the bank does not have a bank. The amount of ink increases. For this reason, the height of the ink surface in the preliminary ejection region 208 is increased. As a result, the solvent vapor concentration in the vicinity of the spare area 107 in the element array area 105 can be leveled, and the drying speed in the vicinity of the spare area 107 in the element array area 105 can be prevented from being selectively increased. By preventing the drying speed of ink in the vicinity of the spare area 107 in the element array area 105 from being selectively increased, drying unevenness can be reduced, and an organic EL layer having a uniform film thickness can be obtained.

On the other hand, as shown in FIG. 12, the number of banks 203 included in the spare area 207 is the same as the number of line banks 106 included in the element array area 105, and the length of the preliminary ejection area 208 in the direction perpendicular to the line direction is set. The length 208L may be the same as the length 104w of the short axis of the line-shaped region 104. However, if the number of banks 203 included in the spare area 207 is the same as the number of line banks 106 included in the element array area 105, ink may land on the top surface of the bank 203 during the preliminary ejection and remain. This is not preferable.

The method of manufacturing the organic EL display panel of the second embodiment may be the same as that of the organic EL display panel of the first embodiment after the base panel is prepared.
As described above, according to the organic EL display panel of the second embodiment, drying unevenness can be reduced, and thus an organic EL display panel having a more uniform film thickness can be obtained.

[Embodiment 3]
In Embodiment 3, an example in which a self-assembled monolayer (SAM) is used instead of a bank will be described.

FIG. 13 is a plan view of the base panel 310 prepared by the method of manufacturing the organic EL display panel according to the third embodiment. The base panel 310 is the same as the base panel 110 of the first embodiment except that a SAM is used instead of a bank. Therefore, the same components as those of the base panel 110 are denoted by the same reference numerals and description thereof is omitted.

As shown in FIG. 13, the base panel 310 has a spare area 107 and an element array area 105. The spare area 107 and the element array area 105 are separated by a boundary SAM 303.

The width 303w of the boundary SAM 303 is preferably approximately the same as the width 103w of the boundary bank 103. The element array region 105 has a line-shaped SAM 306, and the line-shaped SAM 306 defines the line-shaped region 104.

After the base panel 310 is prepared, similarly to the method for manufacturing the organic EL display panel of the first embodiment, 1) the inkjet head 120 is disposed on the spare area 107 (FIG. 14A), and 2) on the spare area 107. Ink is ejected from the nozzle 121 at regular intervals, and ink is landed on the preliminary ejection area 108 (FIG. 14B). 3) The ink jet head 120 is arranged from the preliminary area 107 while maintaining ejection at regular intervals. It moves to the area | region 105 (FIG. 14C), 4) The inkjet head 120 may be moved along a line direction, and the ink may be apply | coated to the linear area | region 104. FIG.

In this embodiment, the boundary SAM 303 that divides the spare area 107 and the element array area 105 has the same width as the boundary bank, but is not forward-tapered unlike the boundary bank 103. For this reason, the ink may remain on the boundary SAM 303. However, since the boundary SAM 303 has no step, the ink applied on the boundary SAM 303 is easily affected by the liquid repellency of the boundary SAM 303. For this reason, even if the boundary SAM 303 is not forwardly tapered, the ink applied on the boundary SAM 303 is torn off due to the liquid repellency of the boundary SAM 303 and is divided, so that no ink remains on the boundary SAM 303.

As described above, according to the present embodiment, by using the SAM instead of the bank, the structure of the organic EL display panel can be simplified in addition to the effects of the first embodiment.

[Embodiment 4]
In the first to third embodiments, a mode in which vertical coating is adopted has been described. In the fourth embodiment, a method for manufacturing an organic EL display panel employing horizontal coating will be described.

The manufacturing method of the organic EL display panel according to the fourth embodiment includes 1) a first step for preparing a base panel (see FIG. 15), and 2) a second step for disposing the inkjet head 120 on the spare area 407 (FIG. 16A), 3) a third step (see FIG. 17A) in which ink is ejected from the nozzle 121 on the preliminary area 407, and the ink is landed on the preliminary ejection area 408, and 4) the inkjet head 120 is moved from the preliminary area 407 to the element. There is a fourth step (see FIG. 17B) that moves to the array region 105, and 5) a fifth step (FIG. 18A) that applies ink to the linear region 104.

In the present embodiment, the direction in which the inkjet head moves in the third step to the fifth step is the same. That is, in this embodiment, the ink jet head is moved along a direction perpendicular to the line direction.

1) In the first step, prepare the base panel. FIG. 15 is a plan view of the base panel 410 prepared in the first step. The same components as those of the base panel 110 of the first embodiment are denoted by the same reference numerals and description thereof is omitted.

As shown in FIG. 15, the base panel 410 includes a substrate 101, a pixel electrode 102, and banks (a boundary bank 403 and a line bank 106).

The substrate 101 has an element array region 105 and a spare region 407 on its surface. In the element array region 105, the pixel electrodes 102 are arranged in a matrix.

The width of the boundary bank 403 may be the same as the width of the line bank 106. The shape of the boundary bank 403 is not particularly limited as long as ink leakage from the preliminary ejection region 408 can be prevented.

The spare area 407 includes one preliminary discharge area 408. Therefore, in the present embodiment, the spare area 407 does not have a bank that divides the spare ejection area 408.

The spare area 407 is adjacent only to the side of the line area 104 on the left side of the drawing in the line direction. Further, if the spare area 407 is not adjacent to the end of the line-like area 104 in the line direction, the spare area 407 may be arranged on both sides of the element arrangement area 105 so as to sandwich the element arrangement area 105. As described above, in the present embodiment, the spare region does not surround the element arrangement region and is adjacent to only the side portion of the line-shaped region 104 in the line direction. Thereby, the ratio of the non-light-emitting area (preliminary area) in the organic EL display panel can be reduced, and the ratio of the light-emitting area (element array area) can be increased.

The long axis of the spare area 407 is parallel to the line direction. The short axis of the spare area 107 is perpendicular to the line direction.

The length 407L of the spare area 407 in the line direction (the length of the major axis of the spare area 407) may be longer than the length of the line area 104 in the line direction (the length of the major axis of the line area 104). preferable. In the present embodiment, the preliminary area 407 includes one preliminary ejection area 408, and therefore, the length of the major axis of the preliminary ejection area 408 is preferably longer than the major axis of the line-shaped area 104. This is because if the length 407L of the long axis of the preliminary area 407 is shorter than the long axis of the line-shaped area 104, the ink may land on an area other than the preliminary discharge area 408 in the preliminary discharge described later. .

The length 407S of the spare area 407 in the direction perpendicular to the line direction (the length of the short axis of the spare area 407) is, for example, the length of the line area 104 perpendicular to the line direction (the length of the line area 104). (Length of the axis) is preferably twice or more, and particularly preferably the width of the pixel composed of three RGB sub-pixels (about 300 μm) or more. Similarly, the length of the short axis of the preliminary ejection region 408 is preferably equal to or greater than the pixel width (about 300 μm).

When the length 407S of the short axis of the preliminary area 407 is less than twice the short axis of the line-shaped area 104, there is a possibility that the ink may land on an area other than the preliminary discharge area 408 during the preliminary discharge.

Further, if the minor axis length 407S of the spare area 407 is equal to or larger than the pixel width, the preliminary ejection is performed even when three inkjet heads supplied with different R, B, or G inks are used in an overlapping manner. In this case, it is possible to prevent the ink ejected from the nozzles of the respective inkjet heads from landing on an area other than the preliminary ejection area 408.

2) FIG. 16A is a diagram showing the second step using a plan view of the base panel, and FIG. 16B is a diagram showing the second step using a cross-sectional view of the base panel taken along line AA in FIG. 16A. is there. As shown in FIGS. 16A and 16B, in the second step, the inkjet head 120 having two or more nozzles 121 and supplied with ink containing the organic layer material is disposed on the preliminary region 407.

As shown in FIG. 16A, in the second step, the arrangement direction of the nozzles 121 of the inkjet head 120 is arranged along the line direction. Further, the arrangement direction of the nozzles 121 of the inkjet head 120 may be inclined with respect to the line direction. The length of the inkjet head 120 in the arrangement direction of the nozzles is equal to or longer than the length of the major axis of the line-shaped region 104.

3) FIG. 17A shows the third step using a cross-sectional view of the base panel. As shown in FIG. 17A, in the third step, ink is ejected (preliminary ejection) from the nozzle 121 on the preliminary area 407, and ink is landed in the preliminary ejection area 408. The ink ejection interval and the number of ejections in the preliminary ejection are preferably the same as the ink ejection interval and the number of ejections in the fifth step. In this way, by ejecting the ink the same number of times at the same interval as the fifth step in the spare area, the period of the meniscus vibration can be stabilized.

Also, the ink jet head 120 is moved in the direction of the element array region 105 during preliminary ejection. The moving direction of the inkjet head is perpendicular to the line direction. By moving the inkjet head 120 toward the element array region 105 during the preliminary ejection, the inkjet moving speed in the fourth step and the fifth step described later is stabilized.

In this way, by performing preliminary ejection on the preliminary area before applying ink to the linear area, it is possible to improve the ink landing accuracy by the nozzle, and the ink is accurately applied to the linear area in the fifth step described later. Can be applied. Further, as described above, since the preliminary area 407 does not have a bank that divides the preliminary ejection area, all of the preliminary ejected ink lands in the preliminary ejection area 408. For this reason, there is no possibility of ink landing on the bank.

4) FIG. 17B shows the fourth step using a cross-sectional view of the base panel. As shown in FIG. 17B, in the fourth step, the inkjet head 120 is moved from the spare area 407 to the element array area 105. When the inkjet head 120 is moved from the preliminary region 407 to the element array region 105, it is preferable to continue driving the nozzle actuator in order to maintain a stable meniscus vibration period obtained by preliminary ejection. On the other hand, unlike the first embodiment, in the present embodiment, ink is not ejected from the nozzles 121 while the inkjet head 120 is moved from the spare area 407 to the element array area 105.

5) FIG. 18A shows the fifth step using the plan view of the base panel; FIG. 18B shows the fifth step using the cross-sectional view of the base panel taken along line AA in FIG. 8A. As shown in FIGS. 18A and 18B, in the fifth step, the inkjet head 120 is moved along a direction perpendicular to the line direction, and ink is applied to the line-shaped region 104.

As shown in FIG. 18B, in the case of horizontal coating, the nozzle 121 does not always eject ink, but alternately repeats a state in which ink is ejected at regular intervals and a state in which ink ejection is stopped. Specifically, only when the inkjet head 120 is positioned on a line-shaped region where a desired color is generated, the nozzle 121 ejects ink a predetermined number of times at regular intervals, and the inkjet head 120 is positioned on the other line-shaped region. Sometimes, the nozzle 121 is adjusted so as not to eject ink. Further, it is preferable to drive the nozzle actuator in order to maintain a stable meniscus vibration period even when ink is not ejected.

In the case of horizontal coating, since one line-shaped region is applied with ink ejected from a plurality of nozzles 121, the film thickness of the organic layer between the line-shaped regions caused by a difference in the amount of ink discharged from each nozzle. Unevenness is prevented.

By repeating the third step to the fifth step, all the line-shaped regions are applied, and an organic layer is formed. Furthermore, an organic EL display panel 400 as shown in FIG. 19 is manufactured by forming a counter electrode on the formed organic layer by sputtering, for example.

As described above, in the present embodiment, the moving direction of the inkjet head 120 is the same in the third step to the fifth step. For this reason, the scanning of the inkjet head 120 is stabilized, and the ink can be stably applied to the line-shaped region 104.

Next, the organic EL display panel manufactured by the method for manufacturing the organic EL display panel of the present embodiment will be described.

FIG. 19 is a plan view of the organic EL display panel 400 of the fourth embodiment. FIG. 20 is a plan view of the organic EL display panel 400 in which the counter electrode 109 is omitted. The same components as those of the organic EL display panel 100 of the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

As shown in FIG. 20, the organic EL display panel 400 includes a substrate 101, a boundary bank 103, a line bank 106, and an organic EL element 140.

The substrate 101 has an element array area 105 in which organic EL elements 140 are arranged in a matrix and a spare area 407 including a preliminary ejection area 408. The spare region 407 does not surround the element array region 105 and is adjacent to only one of the side portions of the line-shaped region 104 in the line direction.

As described above, in the organic EL display panel 400 of the present embodiment, the spare area 407 does not surround the element array area 105. Therefore, the ratio of the non-light emitting area (preliminary area) in the organic EL display panel is reduced, and the light emitting area. The ratio of (element arrangement region) can be increased.

This application claims priority based on Japanese Patent Application No. 2009-053520 filed on Mar. 6, 2009. All the contents described in the application specification are incorporated herein by reference.

The organic EL display panel of the present invention can be applied to, for example, an organic EL display (such as a monitor of an information device terminal such as a large-screen TV or a mobile phone).

100, 400 Organic EL display panel Base panel 110, 210, 310, 410
DESCRIPTION OF SYMBOLS 101 Substrate 102 Pixel electrode 103 Boundary bank 104 Line area 105 Element arrangement area 106 Line bank 107, 207 Preliminary area 108, 208, Preliminary ejection area 109 Counter electrode 120 Inkjet head 121 Nozzle 130 Ink 140 Organic EL element 203 Preliminary ejection area Banks 303, 306 SAM

Claims (14)

1. A substrate having an element arrangement area in which organic EL elements are arranged in a matrix and a spare area composed of one or more preliminary ejection areas;
   A bank disposed on the substrate and separating the spare region and the element array region;
   An organic EL display panel having a line bank disposed on the substrate and defining two or more parallel line areas in the element arrangement area;
   In the line-shaped region, the organic EL elements are arranged in a row,
   The preliminary area is adjacent only to the end of the line-shaped area in the line direction,
   The organic EL display panel, wherein a length of the preliminary ejection region in a direction perpendicular to the line direction is longer than a length of the linear region in a direction perpendicular to the line direction.
2. The width of the bank separating the spare area and the element array area is 10 μm to 300 μm,
   The organic EL display panel according to claim 1, wherein a shape of a bank that divides the spare region and the element array region is a forward tapered shape.
3. 3. The organic EL display panel according to claim 2, wherein a width of a bank separating the spare area and the element array area is 20 μm to 50 μm.
4. 3. The organic EL display panel according to claim 2, wherein a taper angle of a bank separating the spare area and the element arrangement area is 20 ° to 50 °.
5. 2. The organic EL display panel according to claim 1, wherein a contact angle of anisole on a top surface of a bank separating the spare area and the element arrangement area is 30 ° to 70 °.
6. The organic EL display panel according to claim 1, wherein the spare area is composed of one preliminary ejection area.
7. The organic EL display panel according to claim 1, wherein the spare area includes two or more spare ejection areas.
8. A substrate having an element arrangement area in which organic EL elements are arranged in a matrix and a preliminary area composed of a preliminary ejection area;
   A bank disposed on the substrate and separating the spare region and the element array region;
   An organic EL display panel having a line bank disposed on the substrate and defining two or more parallel line areas in the element arrangement area;
   In the line-shaped region, the organic EL elements are arranged in a row,
   The spare area is adjacent only to the side of the line area in the line direction,
   The length of the preliminary ejection region in the direction perpendicular to the line direction is at least twice as long as the length of the linear region in the direction perpendicular to the line direction.
9. A substrate having an element arrangement area in which pixel electrodes are arranged in a matrix and a spare area composed of one or more preliminary ejection areas, and a substrate arranged on the substrate, and separating the spare area from the element arrangement area A base panel having a bank and a line-shaped bank that is arranged on the substrate and defines two or more parallel line-shaped regions in the element array region, wherein the line-shaped region includes: The organic EL elements are arranged in a row, and the preliminary region is adjacent to only the end portion of the line region in the line direction, and the length of the preliminary discharge region in the direction perpendicular to the line direction. Providing a base panel longer than the length of the linear region in a direction perpendicular to the line direction;
   Disposing an inkjet head having two or more nozzles to which ink containing an organic layer material is supplied on the spare area;
   Discharging the ink from the nozzles at regular intervals on the preliminary area, and landing the ink in the preliminary discharge area;
   Moving the inkjet head from the spare region to the element array region while maintaining ejection at each interval;
   Moving the inkjet head along the line direction, and applying the ink to the line-shaped region.
10. 10. The method of manufacturing an organic EL display panel according to claim 9, wherein the interval is 0.05 ms to 1 ms.
11. 10. The method of manufacturing an organic EL display panel according to claim 9, wherein the ink is ejected on the spare area while moving the ink jet head in the element array area direction.
12. 10. The method of manufacturing an organic EL display panel according to claim 9, wherein the amount of ink ejected at one time by one of the nozzles is 3 pl to 20 pl.
13. 10. The method of manufacturing an organic EL display panel according to claim 9, wherein the moving speed of the inkjet head relative to the base panel is 1 mm / s to 100 mm / s.
14. A substrate having an element arrangement area in which pixel electrodes are arranged in a matrix and a spare area composed of a preliminary ejection area, a bank disposed on the substrate and separating the spare area and the element arrangement area; A base panel disposed on the substrate and having two or more line-shaped banks that define two or more parallel line-shaped regions in the element array region, wherein the pixel electrode is disposed in the line-shaped region. Are arranged in a row, the preliminary area is adjacent only to the side of the line area in the line direction, and the length of the preliminary discharge area in the direction perpendicular to the line direction is the length of the line area. Providing a base panel that is at least twice the length in a direction perpendicular to the line direction;
    Disposing an inkjet head having two or more nozzles to which ink containing an organic layer material is supplied on the spare area;
    Discharging the ink from the nozzles on the preliminary area and landing the ink in the preliminary discharge area;
    Moving the inkjet head from the spare area to the element array area;
    Moving the inkjet head along a direction perpendicular to the line direction, and applying the ink to the line-shaped region.
    
    

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