JP2022090638A - Manufacturing device for organic el display panel, manufacturing system, manufacturing method for organic el display panel, and organic el display panel - Google Patents

Abstract

To suppress unintended drying of ink and improve the uniformity of the film thickness of a coating film on a substrate when an organic EL display panel is manufactured.SOLUTION: A manufacturing device for an organic EL display panel includes a transport unit that moves a board, an ink ejection head that ejects ink for forming a functional layer of the organic EL display panel, and a drying suppressing member arranged to face the surface of the substrate on which ink is ejected by the ink ejection head.SELECTED DRAWING: Figure 12

Description

The present invention relates to an organic EL display panel manufacturing apparatus, a manufacturing system, an organic EL display panel manufacturing method, and an organic EL display panel.

Conventionally, as an apparatus for forming a desired pattern on a substrate by using ink in which a functional material is dispersed or dissolved, an inkjet apparatus for ejecting ink as droplets is known. The inkjet device forms a pattern by arranging droplets of ink ejected from the ink ejection head at an arbitrary position on the substrate while relatively moving the substrate and the ink ejection head.

In recent years, inkjet devices have been used in the manufacture of large screen color filters and organic EL (Electro-Luminence) display panels. One of the manufacturing processes of the organic EL display panel is a film forming process of an organic EL film, and an inkjet printing technique is used in this process. According to the wet process in the film forming method using such an inkjet method, uneven drying may occur in the step of drying the coating film, and it is difficult to obtain a uniform film thickness. One of the factors is that a highly volatile organic solvent is used as a solvent for the coating liquid in order to increase the solubility, and as a result, drying proceeds from the middle of film formation.

Conventionally, as a drying method for the purpose of uniform drying, there is a drying method in which a condensing plate is opposed to a coating film surface and the solvent in the coating film is condensed by the condensing plate (for example, Patent Document 1). Drying unevenness often occurs immediately after coating, and drying in the initial stage contributes greatly to the uniformity of drying. Therefore, in Patent Document 1, only in the initial stage of drying immediately after coating, between the condenser plate and the coating film. A drying method has been proposed in which the distance is reduced and held. Further, Patent Document 2 proposes a method for drying a coating film in which the distance between the condensed surface of the condensed plate and the coating film surface on the substrate is maintained at a constant value. In Patent Document 3, after coating on a base material by an inkjet method, the surface of the base material is covered with a lid-like structure, and the solvent is moved onto a hot plate in order to suppress volatilization and heat-dry. It has been disclosed. Patent Document 4 discloses that after applying a color filter ink on a substrate with an inkjet head to a colored layer region, the upper part of the colored layer is covered with a sheet to suppress the volatilization of the solvent.

Japanese Unexamined Patent Publication No. 2011-25244 Japanese Unexamined Patent Publication No. 2013-250002 Japanese Unexamined Patent Publication No. 2004-253179 Japanese Unexamined Patent Publication No. 2008-249986

However, the method of maintaining the distance between the condensing plate and the coating film according to the above-mentioned prior art document assumes a configuration in which the coating method for a film or the like is very fast and a one-way coating method. Therefore, in the method of the above-mentioned prior art document, when the coating speed is relatively slow as in the inkjet method, or when a plurality of scans are required for coating, the uniformity of drying is sufficiently realized. Can't. In the case of an electronic device such as an organic EL element, the coating film is a very thin film and has a characteristic of being easily dried at the time of formation. In order to obtain the uniformity of the film thickness required for an electronic device such as an organic EL element to exert its function well, it is necessary to suppress drying immediately after application, and the time of the transport process is also dried. It is required to be suppressed.

For example, Patent Document 3 has a problem that it is heated and dried on a hot plate in order to be rapidly solidified, and the drying is not stable due to a rapid temperature rise due to the hot plate, and the film thickness tends to be uneven. Further, Patent Document 4 is a technique related to manufacturing a color filter, and has not been used for forming an organic EL display element having a different film thickness and required system.

The present invention has been made to solve the above problems, and suppresses unintended drying of ink during the manufacture of an organic EL display panel, and improves the uniformity of the film thickness of the coating film on the substrate. The purpose is.

In order to solve the above problems, the present invention has the following configurations. That is, it is a manufacturing device for an organic EL display panel.
A transport unit that moves the board,
An ink ejection head for ejecting ink for forming a functional layer of the organic EL display panel, and an ink ejection head.
A drying suppressing member is provided which is arranged so as to face the surface of the substrate on which ink is ejected by the ink ejection head.

In addition, another embodiment of the present invention has the following configuration. That is, the organic EL display panel manufacturing system includes a manufacturing device and a drying device for drying the substrate on which ink is discharged.
The manufacturing equipment is
A transport unit that moves the board,
An ink ejection head for ejecting ink for forming a functional layer of the organic EL display panel, and an ink ejection head.
It is provided with a drying suppressing member arranged so as to face the surface of the substrate on which ink is ejected by the ink ejection head.
The drying suppressing member is arranged so as to face each other so that the distance from the surface of the substrate is within a predetermined range while being transported from a position adjacent to the ink ejection head to the drying device by the transport unit. ..

In addition, another embodiment of the present invention has the following configuration. That is, it is a method for manufacturing an organic EL display panel.
Ink is ejected onto the substrate by the ink ejection head to form the functional layer of the organic EL display panel.
The drying suppressing member is arranged so as to face the surface of the substrate on which the ink is ejected by the ink ejection head.

In addition, another embodiment of the present invention has the following configuration. That is,
Ink is ejected onto the substrate by the ink ejection head to form the functional layer of the organic EL display panel.
An organic EL display panel manufactured by a manufacturing method in which a drying suppressing member is arranged so as to face the surface of the substrate on which ink is ejected by the ink ejection head.

According to the present invention, it is possible to suppress unintended drying of ink and improve the uniformity of the film thickness on the substrate when manufacturing an organic EL display panel.

The schematic diagram which shows the structural example of the inkjet apparatus which concerns on one Embodiment of this invention. The schematic diagram which shows the structural example of the inkjet apparatus which concerns on one Embodiment of this invention. The figure for demonstrating the ejection by the ink ejection head which concerns on one Embodiment of this invention. The schematic diagram which shows the structural example of the drying apparatus which concerns on one Embodiment of this invention. The figure for demonstrating the operation at the time of layer formation by the ink ejection head which concerns on one Embodiment of this invention. The figure for demonstrating the operation at the time of layer formation by the ink ejection head which concerns on one Embodiment of this invention. The figure for demonstrating the operation at the time of layer formation by the ink ejection head which concerns on one Embodiment of this invention. The figure for demonstrating the operation at the time of layer formation by the ink ejection head which concerns on one Embodiment of this invention. The figure for demonstrating the operation at the time of layer formation by the ink ejection head which concerns on one Embodiment of this invention. The figure for demonstrating the operation at the time of layer formation by the ink ejection head which concerns on one Embodiment of this invention. The figure for demonstrating the operation at the time of layer formation by the ink ejection head which concerns on one Embodiment of this invention. The figure for demonstrating the transport operation of the base material after layer formation which concerns on one Embodiment of this invention. The figure for demonstrating the transport operation of the base material after layer formation which concerns on one Embodiment of this invention. The plan view which shows the structural example of the display panel which concerns on one Embodiment of this invention. The plan view which shows the structural example of the display panel which concerns on one Embodiment of this invention. The cross-sectional view which shows the structural example of the display panel which concerns on one Embodiment of this invention. The flowchart of the manufacturing process of the display panel which concerns on one Embodiment of this invention. The flowchart of the layer forming process which concerns on one Embodiment of this invention. The schematic diagram which shows the structural example of the drying apparatus which concerns on one Embodiment of this invention. The flowchart of the drying process which concerns on one Embodiment of this invention. The graph for demonstrating the change of the atmospheric pressure in the drying process which concerns on one Embodiment of this invention. The figure for demonstrating the test which concerns on one Embodiment of this invention. The graph for demonstrating the effect which concerns on one Embodiment of this invention. The figure which shows the structural example of the drying | drying suppressing plate which concerns on other embodiment of this invention. The figure which shows the structural example of the drying | drying suppressing plate which concerns on other embodiment of this invention.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings and the like. It should be noted that the embodiments described below are embodiments for explaining the invention of the present application, and are not intended to be interpreted in a limited manner, and are described in each embodiment. Not all configurations are essential configurations for solving the problems of the present invention. Further, in each drawing, the same reference number is assigned to the same component to show the correspondence.

<First Embodiment>
[Device configuration]
An example of the configuration of an inkjet device that operates as a manufacturing device for an organic EL display panel according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a side view schematically showing an outline of the configuration of the inkjet device 1 according to the present embodiment. FIG. 2 is a plan view schematically showing an outline of the configuration of the inkjet device 1 according to the present embodiment. In the following, the main scanning direction of the stage 40 (that is, the transport direction of the base material) is the X-axis direction, the sub-scanning direction orthogonal to the main scanning direction is the Y-axis direction, and the X-axis direction and the Y-axis direction are orthogonal to each other. The vertical direction is the Z-axis direction. Further, the rotation direction around the Z-axis direction is set to the θ direction. In each figure, it is assumed that each axial direction corresponds to each other.

The inkjet device 1 spans an X-axis table 10 extending in the main scanning direction (X-axis direction) and a pair of Ys extending in the sub-scanning direction (Y-axis direction) so as to straddle the X-axis table 10. It has an axis table 11. A pair of X-axis guide rails 12 are provided on the upper surface of the X-axis table 10 so as to extend in the X-axis direction, and an X-axis linear motor (not shown) is provided on the X-axis guide rail 12. A Y-axis guide rail 13 is provided on the upper surface of the Y-axis table 11 so as to extend in the Y-axis direction, and a Y-axis linear motor (not shown) is provided on the Y-axis guide rail 13. A carriage unit 20 is provided on the pair of Y-axis tables 11.

In the following description, the side where the base material B is located in FIGS. 1 and 2 is defined as the upstream side in the transport direction (X-axis direction) of the base material B, and the downstream side toward the ink ejection head 23. show. Further, the base material B in the description of each device and operation after [device configuration] may be used as a substrate in the production of the organic EL display panel described later. That is, in the production of the organic EL panel described later, the base material B can be read as a substrate.

(Carriage unit)
The carriage unit 20 includes a carriage support portion 21, a carriage 22, and an ink ejection head 23. The lower surface of the carriage unit 20 is provided with one or more carriages 22 and one or more ink ejection heads 23, depending on the type of ink ejected. In the present embodiment, for example, a plurality of ink ejection heads 23 having a line head system configuration corresponding to the substrate width in the Y-axis direction are provided. A plurality of nozzles are formed on the lower surface of the ink ejection head 23, that is, the ink ejection surface, and ink droplets are ejected from the nozzles. For example, when ejecting three types of ink corresponding to three colors of R (Red), G (Green), and B (Blue), three rows of ink ejection heads 23 are provided. The number of types of ink that the inkjet device 1 can handle is not particularly limited, and may be increased or decreased depending on the configuration of the product. Further, a supply unit (not shown) for supplying ink is connected to the carriage unit 20, and ink is supplied in a timely manner.

The carriage support portion 21 is attached to the Y-axis guide rail 13 and is configured to be movable in the Y-axis direction by a Y-axis linear motor (not shown) provided on the Y-axis guide rail 13. For example, the carriage unit 20 moves so as to be located on the X-axis table 10 as shown in FIG. 2 when the ink is ejected, and moves to the retracted position along the Y-axis guide rail 13 when the ink ejection head 23 is cleaned. , It may be configured to perform a cleaning operation. Examples of the cleaning operation include preliminary ejection of ink and wiping of the ejection surface of the ink ejection head 23.

(Drying suppression member)
Further, a drying suppressing member for suppressing the drying of the ink applied to the base material B is installed around the ink ejection head 23. The drying suppressing member is arranged so as to face at least the ink-coated region on the base material B so that the lower surface of the drying suppressing member covers at least the entire ink-coated region on the base material B. By arranging the drying suppressing member in this way, the solvent volatilized from the ink was filled between the lower surface of the drying suppressing member and the upper surface of the base material B (the surface on which the ink was applied), and the solvent was applied onto the base material B. It is considered that the volatilization of the solvent contained in the ink is suppressed and the drying can be suppressed. In FIG. 2, the drying suppressing plate F is arranged as a plate-shaped drying suppressing member, but the drying suppressing member may have a facing surface so as to cover the entire area on the base material B to which the ink is applied. , It is not limited to a plate shape. The drying suppressing member is preferably plate-shaped because it is lightweight and easy to move into the chamber of the next step such as a drying device described later because it is thin.

The material of the drying suppressing plate F is not particularly limited, but at least one having resistance to the organic solvent contained in the ink used for forming the organic EL display panel is desirable. For example, examples of the material used for the drying suppression plate F include a stainless steel material. Further, in the present embodiment, a plate-shaped member as an example of the drying suppressing member will be described as an example, but the shape is not particularly limited.

In the present embodiment, the drying suppression plate F is installed at a position adjacent to the ink ejection head 23 in order to suppress the drying of the ink ejected on the base material. The installation position here is a position in which the base material B on which the ink is ejected moves, and covers the entire area on the base material B to which the ink is applied and faces the base material B. FIG. 1 shows an example in which the stage 40 for moving the base material B is installed on the downstream side and the upstream side with the ink ejection head 23 as a reference in the moving direction (X-axis direction). In FIG. 2, the drying suppression plate F installed on the upstream side of the ink ejection head 23 is omitted in the moving direction (X-axis direction) of the stage 40, but it is assumed that the stage 40 is installed in the same manner as in FIG. Details of the arrangement and operation of the drying suppression plate F will be described later.

FIG. 3 is a diagram schematically showing a situation in which ink droplets 202 are ejected from the ink ejection head 23. The ink ejection head 23 according to the present embodiment shows an example using the piezo method. In the piezo method, a drive voltage is applied to a piezoelectric element (not shown) inside the ink ejection head 23 to expand and contract the piezoelectric element, and a predetermined amount of ink droplet 202 is ejected from a pore called a nozzle hole 201. Let me. The ejected ink droplet 202 lands on the base material B arranged on the stage 40. The arrangement and number of the nozzle holes 201 are not particularly limited, and are not limited to the example shown in FIG.

(stage)
The stage 40 is, for example, a vacuum suction stage, and can suck and fix the base material B. The stage 40 is rotatably supported in the θ direction around the Z axis by a stage rotation mechanism 41 provided on the lower surface side of the stage 40. The stage rotation mechanism 41 is supported by an X-axis slider 42 provided on the lower surface side of the stage rotation mechanism 41. The X-axis slider 42 is attached to the X-axis guide rail 12, and is configured to be movable in the X-axis direction by an X-axis linear motor (not shown) provided on the X-axis guide rail 12. By moving the stage 40 in the X-axis direction, the base material B adsorbed on the stage 40 can be conveyed in the X-axis direction.

Although details will be described later, the display panel that can be manufactured by using the inkjet device 1 according to the present embodiment is composed of a plurality of layers. These layers include one or more layers that can be formed by an inkjet method. Therefore, when forming each of these layers, a plurality of configurations shown in FIGS. 1 and 2 can be provided and applied.

(Control device)
The inkjet device 1 includes a control device 50. The control device 50 may be realized by, for example, an information processing device including a control unit, a storage unit, and an output unit (not shown). The control unit may be composed of a CPU (Central Processing Unit), an MPU (Micro Processing Unit), a DSP (Digital Single Processor), a dedicated circuit, or the like. The storage unit is composed of volatile and non-volatile storage media such as HDD (Hard Disk Drive), ROM (Read Only Memory) and RAM (Random Access Memory), and various information can be input and output according to instructions from the control unit. It is possible. Further, the storage unit stores a program for realizing the process according to the present embodiment. The output unit is composed of a speaker, a light, a display device such as a liquid crystal display, or the like, and performs various outputs according to instructions from the control unit. The output method by the output device is not particularly limited, but may be, for example, a visual output by screen output. Further, the output unit may be a network interface having a communication function, and may perform an output operation by transmitting data to an external device (not shown) via a network (not shown).

The control device 50 comprehensively controls, for example, the positions of the stage 40 and the carriage unit 20 described above, and the ink ejection control by the ink ejection head 23. In ink ejection, the control device 50 outputs the control signal to the ink ejection head 23 according to the formed pixel pattern. In addition, the control device 50 performs various controls for generating the display panel D. In the present embodiment, an organic EL display panel will be described as an example of the display panel D.

(Drying device)
Next, the configuration of the drying device 60 used for manufacturing the display panel D according to the present embodiment will be described. FIG. 4 is a schematic view showing a configuration example of the drying device 60 used in the drying step according to the present embodiment, and here, it is assumed that a vacuum dryer that performs drying by reduced pressure is used. The base material B to be dried is carried into the chamber 63 of the drying device 60 and installed on the support table 61. After that, the drying device 60 reduces the air pressure in the chamber 63 by operating the vacuum pump 62 to perform drying. The arrows in FIG. 4 indicate the flow of gas (steam) with depressurization. The details of the operation of the drying device 60 according to the present embodiment will be described later together with the flowchart. The drying device 60 may be provided as a part of the organic EL display panel manufacturing system according to the present embodiment, or may be provided as a separate device.

Further, it is considered preferable that the vacuum dryer is not heated under reduced pressure. The reason for this is that the solvent in the ink volatilizes violently due to heating and becomes unstable, so that the film thickness in the surface of the display panel tends to be non-uniform. The heating here means heating in a vacuum dryer by a heating mechanism for the purpose of raising the temperature of the base material.

(ink)
The ink for forming the layer constituting the organic EL display panel according to the present embodiment is composed of a solute containing a functional material and a solvent containing an organic solvent. The functional material is for realizing the function of the layer formed by the inkjet method in the layer constituting the organic EL display panel. The organic solvent needs to be an organic solvent in which a solute containing a functional material can be dissolved or dispersed.

In addition to the above-mentioned organic solvent, the ink composition appropriately contains additives such as a surfactant for surface adjustment and an ultraviolet absorber, a light stabilizer, and an antioxidant for stabilizing the storage of the ink composition. You may.

[Layer formation operation]
Next, the operation when forming the layer of the organic EL display panel by using the inkjet device 1 according to the present embodiment will be described with reference to FIGS. 5 to 13. FIG. 5 is a diagram showing a state in which the base material B is conveyed directly below the ink ejection head 23. The stage 40 is controlled to a predetermined start position, and then the base material B is mounted. Here, it is assumed that the mounting position of the base material B on the stage 40 is the position shown in FIG. Further, it is assumed that the ink ejection head 23 is also located on the transport path of the base material B as shown in FIG. The base material B may be mounted on the stage 40 by using a mounting device (not shown) provided separately. Further, in the present embodiment, the size of the base material B is assumed to be 370 mm × 470 mm, but the description is not limited to this.

FIG. 6 is a diagram showing an ink application start position on the base material B by the ink ejection head 23. The end of the ink application position of the base material B is located directly below the ink ejection head 23 on the most upstream side of the plurality of ink ejection heads 23.

FIG. 7 shows a state in which the application of ink has started. The ink droplet 202 is ejected from the ink ejection head 23, and the ink droplet K is applied onto the base material B. Here, the ink droplet after landing on the base material B is shown as K. Further, in the present embodiment, as shown in FIG. 1, the entire surface of the base material B is configured to pass below the ink ejection head 23. The stage 40 operates while the ink is being ejected, whereby the base material B moves in a timely manner. In this embodiment, the ink droplets K after landing are individually shown for the sake of simplicity, but in reality, the ink droplets 202 are not limited to one ink droplet 202, and a plurality of ink droplets 202 are used. The layers are homogenized to form a predetermined thickness. In the figure, the case where the droplet K is ejected onto the flat base material B has been schematically described, but the condition is not limited to such a condition. The same applies to the case where ink is ejected into a region partitioned by a bank of a base material with a bank, which will be described later, in actual panel manufacturing.

FIG. 8 shows the position of the base material B on which the ink droplet K is formed by the ink application operation by one scanning. If necessary, the base material B is reciprocated (reciprocated) along the X-axis direction, and ink is further applied onto the base material B. 9 to 11 show the reciprocating motion and the state of the base material B formed as a result.

As shown in FIGS. 5 to 11, in the present embodiment, the drying suppressing plate F is installed so as to face each other at a position including the moving range of the base material B when the ink coating operation is performed. .. As a result, the drying suppression plate F covers at least the entire area on the base material B to which the ink is applied. In the above example, the base material B shows a configuration in which the base material B moves along the X-axis direction. For example, if the ink ejection head 23 and the base material B are configured to apply ink while moving along the Y-axis direction at a position directly below the ink ejection head 23, the base material is applied at that time. The drying suppression plate F may be installed so as to face the range where B is located. That is, the carriage 22 in FIG. 2, the drying suppression plate F on the downstream side of the carriage 22 shown, and the upstream side of the carriage 22 not shown, which is the range in the Y-axis direction in which the base material B is located. By installing the drying suppression plate F so as to face the base material B so as to be adjacent to the positions of all three members of the drying suppression plate F in the Y-axis direction, the drying suppression plate F can be at least the base material. It is preferable because it can cover the entire area on B where the ink is applied.

Further, in the present embodiment, as shown in FIG. 5, drying suppression is performed so that the distance d between the lower surface of the drying suppression plate F and the upper surface (ink coated surface) of the base material B is within a certain range. The plate F is installed. The distance d here is not particularly limited, but is defined according to the composition of the ink and the characteristics of drying. In the present embodiment, the distance d is assumed to be 5 to 10 mm, and will be described below as 5 mm. Further, this distance d is assumed to be maintained at least from the start of ink application to the delivery to the drying device 60 described later.

Note that FIGS. 5 to 11 show an example in which the lower surface of the drying suppression plate F and the ejection surface of the ink ejection head 23 are at the same position in the Z-axis direction, but the present invention is not limited to this. For example, the lower surface of the drying suppression plate F may be arranged so as to be closer to the base material B than the ejection surface of the ink ejection head 23. The height of each surface may be adjusted according to the drying characteristics of the ink, the convenience of applying the ink, and the like.

(Transport section)
Next, the transfer to the drying device 60 for drying the base material B on which the ink droplets K are ejected will be described. As shown in FIGS. 5 to 11, the drying suppression plate F according to the present embodiment is arranged at a position adjacent to the ink ejection head 23 when the ink is applied. After the ink application operation, the base material B is transferred to the drying device 60 as shown in FIG. At that time, as the base material B (stage 40) moves, the drying suppression plate F is also moved in a state of facing the base material B. At this time, the base material B and the drying suppression plate F are transported by a transport unit (not shown). That is, the transport unit is a mechanism configured to transport the base material B and the drying suppression plate F. After that, the base material B is carried into the drying device 60, and the drying step is carried out by the drying device 60. The base material B may be carried into the drying device 60 as it is by the transport unit, or may be carried out by using a separately provided carry-in device (not shown) or the like.

In this embodiment, an example of two carry-in configurations is shown. FIG. 12 shows a schematic view when only the base material B is carried into the drying apparatus 60. In this case, the base material B and the drying suppressing plate F are maintained in a state of facing each other at a distance d until immediately before being carried into the drying device 60. Then, only the base material B is carried into the drying device 60 and installed on the support 61 in the drying device 60.

FIG. 13 shows a schematic view when the base material B and the drying suppression plate F are carried into the drying apparatus 60. In this case, the base material B and the drying suppressing plate F are maintained in a state of facing each other at a distance d and are carried into the drying device 60. Then, the base material B and the drying suppression plate F are installed on the support 61 in the drying device 60 in a state of facing each other.

In addition, in FIGS. 12 and 13, an example in which the drying suppressing plate F installed on the downstream side of the ink ejection head 23 moves in conjunction with the transportation of the base material B is shown. The present invention is not limited to this, and the drying suppression plate F located on the upstream side of the ink ejection head 23 may also perform an operation of interlocking with the base material B at the time of ink application or the like.

[Configuration of display panel D]
Subsequently, the display panel D that can be manufactured by using the above-mentioned ink ejection amount measuring method will be described with reference to FIGS. 14 to 16. FIG. 14 is a schematic plan view showing a configuration example of the display panel D according to the present embodiment. Note that FIG. 14 is a schematic diagram, and the scale thereof may differ from the actual scale.

The display panel D according to the present embodiment is an organic EL display panel utilizing the electroluminescence phenomenon of an organic compound. In the display panel D, a plurality of organic EL display elements, each of which constitutes a pixel, are arranged in a matrix on a substrate (hereinafter referred to as "TFT substrate") on which a thin film transistor (TFT) is formed, and the upper surface thereof is formed. It has a top-emission type configuration that emits light from (color filter substrate 131 side). Here, the X direction, the Y direction, and the Z direction in FIG. 14 are also referred to as a row direction, a column direction, and a thickness direction in the display panel D, respectively.

As shown in FIG. 14, the display panel D according to the present embodiment includes a compartmentalized area 10a and a non-partitioned region 10b located around the compartmentalized area 10a. The partition area 10a is partitioned on the substrate 100 in a matrix by banks 122 that regulate the emission units of each color (here, three colors of RGB). The bank 122 along the Y-axis direction will be referred to as a column bank 122Y, and the bank along the X-axis direction will be referred to as a row bank 122X.

In the non-partitioned area 10b, a sealing member 300 on a rectangle surrounding the sectioned area 10a is formed. The partition area 10a is composed of a display pixel arrangement area 10e including the center of the substrate 100 and a non-light emitting area 10ne located around the display pixel arrangement area 10e. The display pixel arrangement area 10e is an area in which an organic EL display element is formed in each section regulated by the column bank 122Y and the row bank 122X. On the other hand, the non-light emitting region 10ne is a region in which the organic EL display element is not formed.

FIG. 15 is an enlarged plan view of a part of the display pixel arrangement area 10e shown in FIG. 14 and is a part of the area 10c. In the display pixel arrangement region 10e, unit elements 100e corresponding to the organic EL display elements are arranged on a matrix. The unit element 100e is a region that emits light due to an organic compound. In this example, the unit element 100e includes a self-luminous region 100aR that emits light in red (R), a self-luminous region 100aG that emits light in green, and a self-luminous region 100a corresponding to three colors of self-luminous region 100aB in blue. Will be done.

Further, as shown in FIG. 15, a plurality of pixel electrodes 119 are arranged on the substrate 100 in a row direction and a column direction, respectively, in a state of being separated by a predetermined distance. The pixel electrodes 119 arranged in a matrix correspond to the self-luminous regions 100aR, 100aG, and 100aB arranged in order in the row direction. Further, the region other than the self-luminous region 100a is the non-self-luminous region 100b. The non-self-luminous region 100b is provided with a contact hole 119c for connecting the pixel electrode 119 and the source of the TFT. Further, the non-self-luminous region 100b is provided with a contact region 119b for electrically connecting to the pixel electrode 119.

FIG. 16 is a schematic cross-sectional view of a position cut at X1-X1 shown in FIG. As shown in FIG. 16, in the display panel D according to the present embodiment, a substrate 100 (TFT substrate) in which a thin film transistor is formed downward in the Z-axis direction is configured, and an organic EL element portion as a light emitting element portion is formed on the substrate 100 (TFT substrate). It is configured. The organic EL element unit is composed of a plurality of layers, and the above-mentioned inkjet device 1 can be applied when forming a part of the layers. As a plurality of layers constituting the organic EL element portion, a pixel electrode 119, a hole injection layer 120, a hole transport layer 121, a bank 122, a light emitting layer 123, an electron transport layer 124, a counter electrode 125, a sealing layer 126, and a junction are used. Layer 127 and a color filter substrate 131 are included. Further, the color filter substrate 131 includes a color filter layer 128 and an upper substrate 130. Hereinafter, the parts constituting the display panel D will be described.

(Substrate (TFT substrate))
The substrate 100 is a support member for the display panel D, and is a base material (not shown), a thin film transistor (TFT) layer (not shown) formed on the base material, and layers formed on the base material and the TFT layer. It has an insulating layer (not shown).

The base material (not shown) constituting the substrate 100 is a support member of the display panel D and has a flat plate shape. As the material of the base material, a material having an electrically insulating property, for example, a glass material, a resin material, a semiconductor material, a metal material coated with an insulating layer, or the like can be used.

The TFT layer (not shown) constituting the substrate 100 is composed of a plurality of TFTs formed on the upper surface of the substrate and wiring. The TFT electrically connects the pixel electrode 119 corresponding to itself and the external power supply (not shown) in response to a drive signal from the external circuit of the display panel D, and includes electrodes, semiconductor layers, insulating layers, and the like. It consists of a multi-layer structure. The wiring (not shown) electrically connects a TFT, a pixel electrode 119, an external power supply, an external circuit, and the like. The interlayer insulating layer located on the upper surface of the substrate 100 flattens at least a part of the upper surface of the substrate 100 having irregularities due to the TFT layer. Further, the interlayer insulating layer fills the space between the wiring and the TFT, and electrically insulates the space between the wiring and the TFT.

(Pixel electrode)
A pixel electrode 119 is provided on an interlayer insulating layer (not shown) located on the upper surface of the substrate 100. The pixel electrode 119 is for supplying carriers to the light emitting layer 123, and for example, when functioning as an anode, supplies holes to the light emitting layer 123. The pixel electrode 119 has a rectangular flat plate shape. Further, through the contact hole formed on the upper surface of the substrate 100, the connection recess of the pixel electrode 119 in which a part of the pixel electrode 119 is recessed in the direction of the substrate 100 and the source of the TFT are connected.

The pixel electrode 119 is made of a metal material. In the case of a top-emission type organic EL display panel, the chromaticity of the emitted light is adjusted and the brightness is increased by optimally setting the layer thickness and adopting the optical resonator structure. Therefore, the surface portion of the pixel electrode 119 has high reflectivity. The pixel electrode 119 may have a structure in which a plurality of films selected from a metal layer, an alloy layer, and a transparent conductive film are laminated.

(Hole injection layer, hole transport layer)
The hole injection layer 120 and the hole transport layer 121 are laminated in this order on the pixel electrode 119, and the hole transport layer 121 is in contact with the hole injection layer 120. The hole injection layer 120 and the hole transport layer 121 have a function of transporting the holes injected from the pixel electrode 119 to the light emitting layer 123.

The hole injection layer 120 and the hole transport layer 121 can be formed by using the inkjet device 1 shown in FIG. The organic solvent used as the ink for forming the hole injection layer 120 and the hole transport layer 121 is not particularly limited as long as it dissolves the hole injection material and the hole transport material.

(bank)
A bank 122 made of an insulator is formed so as to cover the edges of the pixel electrode 119, the hole injection layer 120, and the hole transport layer 121. The bank 122 is formed by using an organic material such as a resin and is insulated in order to prevent a current leak in the thickness direction (Z-axis direction) between the outer edge of the pixel electrode 119 and the counter electrode 125. It is desirable that the property has an insulating property having a volume resistivity of 1 × 10 ⁶ Ωcm or more.

Further, since the bank 122 may be subjected to etching treatment, baking treatment, etc. during the manufacturing process, the bank 122 is formed of a material having high resistance to such treatments so as not to be excessively deformed or deteriorated. Is preferable. Further, in order to give the surface liquid repellency, the surface of the bank 122 may be treated with fluorine by CVD (Chemical Vapor Deposition) or the like.

(Light emitting layer)
A light emitting layer 123 that emits light in each color is formed on the display panel D. Specific examples of the colors here include three colors, R (Red), G (Green), and B (Blue). The light emitting layer 123 is a layer made of an organic compound, and has a function of emitting light by recombining holes and electrons inside. In the light emitting layer 123, only the portion to which the carrier is supplied from the pixel electrode 119 emits light. The light emitting layer 123 can be formed by using the inkjet device 1 shown in FIG.

As the material used for forming the light emitting layer 123, it is necessary to use a light emitting organic material that can form a film by using a wet printing method. The light emitting layer 123 may be a layer made of a known material that can be used for the light emitting layer (layer having a light emitting function) of the organic EL element portion, and the material or the like is not particularly limited, but the light emitting layer made of an organic material. Is preferable. For example, it is preferable to use a layer formed of an organic substance (low molecular weight compound and high molecular weight compound) that emits fluorescence or phosphorescence as a luminescent material and a dopant that assists the organic substance (low molecular weight compound and high molecular weight compound).

(Electron transport layer)
An electron transport layer 124 is formed on the light emitting layer 123 on the bank 122 and in the opening defined by the bank 122. The electron transport layer 124 has a function of transporting electrons injected from the counter electrode 125 to the light emitting layer 123.

(Counter electrode)
The counter electrode 125 is laminated and formed so as to cover the electron transport layer 124. The counter electrode 125 may be formed in a continuous state over the entire display panel D and may be connected to the bus bar wiring in pixel units or several pixel units (not shown). The counter electrode 125 is paired with the pixel electrode 119 to sandwich the light emitting layer 123 to form an energization path, and supplies carriers to the light emitting layer 123. When the counter electrode 125 functions as a cathode, for example, it supplies electrons to the light emitting layer 123. The counter electrode 125 is formed along the surface of the electron transport layer 124, and is a common electrode for each of the light emitting layers 123 formed between the banks 122. A conductive material having light transmittance is used for the counter electrode 125.

(Sealing layer)
The sealing layer 126 is laminated so as to cover the counter electrode 125. The sealing layer 126 is formed to prevent the light emitting layer 123 from deteriorating due to contact with moisture, air, or the like. The sealing layer 126 is provided over the entire surface of the display panel D so as to cover the upper surface of the counter electrode 125.

(Joining layer)
A color filter substrate 131 composed of an upper substrate 130 and a color filter layer 128 is arranged above the sealing layer 126 in the Z-axis direction, and the sealing layer 126 and the color filter substrate 131 are bonded by a bonding layer 127. .. The bonding layer 127 has a function of bonding the back panel composed of each layer from the substrate 100 to the sealing layer 126 and the color filter substrate 131, and preventing each layer from being exposed to moisture or air.

(Upper board)
Since the display panel D is a top emission type for the upper substrate 130 constituting the color filter substrate 131, for example, a light transmissive material such as a cover glass or a transparent resin film is used. Further, the display panel D can improve the rigidity and prevent the intrusion of moisture, air, etc. by the upper substrate 130.

(Color filter layer)
A color filter layer 128 corresponding to each color is formed on the color filter substrate 131 at a position corresponding to a light emitting region of a pixel. The light emitting region corresponds to the position of the light emitting layer 123 formed between the banks 122. The color filter layer 128 is a transparent layer provided for transmitting visible light having a wavelength corresponding to each color (for example, R, G, B), and transmits light emitted from each color pixel to transmit the chromaticity. Has the function of correcting. Specifically, the color filter layer 128 is formed by applying an ink containing a color filter material and a solvent to an upper substrate 130 made of a cover glass for forming a color filter in which a plurality of openings are formed in a matrix in pixel units. It is formed by the step of applying.

[Manufacturing of display panel D]
Next, the manufacturing process of the display panel D will be described with reference to specific examples. Among the configurations of the display panel D shown in FIG. 16, the light emitting layer 123, the hole injection layer 120, and the hole transport layer 121 can be formed by an inkjet method. Therefore, in the present embodiment, the inkjet method will be described as being used when forming these three layers. FIG. 17 is a flowchart showing a manufacturing process of the display panel D.

In the present embodiment, the ink ejection head 23 corresponding to each layer is provided. That is, the configurations shown in FIGS. 1 to 4 are prepared for forming the light emitting layer 123, the hole injection layer 120, and the hole transport layer 121, respectively. Further, for the sake of simplicity, the operation for manufacturing the display panel D will be described as being comprehensively controlled by the control device 50. When this operation flow starts, the substrate 100 composed of the base material, the TFT layer, and the interlayer insulating layer is prepared.

In S1701, the control device 50 forms the pixel electrode 119 on the substrate 100. Specifically, a contact hole (not shown) is provided in the interlayer insulating layer of the substrate 100 to form the pixel electrode 119. The pixel electrode 119 is formed by forming a metal film by a sputtering method, a vacuum vapor deposition method, or the like, and then patterning by a photolithography method and an etching method. The pixel electrode 119 is electrically connected to the electrodes of the TFTs constituting the substrate 100.

In S1702, the control device 50 forms the bank 122. In the formation of the bank 122, the bank 122 is formed along the predetermined direction, and then the bank in the direction orthogonal to the predetermined direction is formed. The formation of the bank 122 is performed by laminating a film made of a constituent material of the bank 122 (for example, a photosensitive resin material). Then, the resin film is patterned to sequentially form banks. The patterning of the bank may be performed by exposing the upper part of the resin film using a photomask and performing a developing step and a firing step (for example, about 230 ° C. for about 60 minutes).

In the process of forming the bank 122, first, a spin coating method or the like is used to form a photosensitive resin film made of an organic photosensitive resin material, for example, an acrylic resin, a polyimide resin, a novolak type phenol resin, or the like. Then, after drying to volatilize the solvent to some extent, a photomask having a predetermined opening is layered. Further, ultraviolet irradiation is performed from above to expose a photoresist made of a photosensitive resin or the like, and the pattern of the photomask is transferred to the photoresist. Subsequently, the photosensitive resin is developed to form an insulating layer in which the bank 122 is patterned. Generally, a photoresist called a positive type is used. In the positive type, the exposed part is removed by development. The portion of the mask pattern that is not exposed is not developed and the bank 122 remains with a certain thickness.

In S1703, the control device 50 laminates and forms the hole injection layer 120 on the pixel electrode 119. The hole injection layer 120 can be formed by an inkjet method using an ink in which a conductive polymer material is dissolved in an organic solvent. Details of this step will be described later with reference to FIG.

In S1704, the control device 50 laminates and forms the hole transport layer 121 on the hole injection layer 120. The hole transport layer 121 can be formed by an inkjet method using an ink in which a conductive polymer material is dissolved in an organic solvent. Details of this step will be described later with reference to FIG.

In S1705, the control device 50 laminates and forms the light emitting layer 123 on the hole transport layer 121 at a predetermined position defined by the bank 122. Details of this step will be described later with reference to FIG.

In S1706, the control device 50 laminates and forms the electron transport layer 124 on the light emitting layer 123. The electron transport layer 124 can be formed by using a vacuum vapor deposition method or the like.

In S1707, the control device 50 laminates and forms the counter electrode 125 so as to cover the electron transport layer 124 as a solid film. The counter electrode 125 can be formed by using a CVD method, a sputtering method, or the like.

In S1708, the control device 50 laminates and forms the sealing layer 126 so as to cover the counter electrode 125 as a solid film. Like the counter electrode 125, the sealing layer 126 can be formed by using a CVD method, a sputtering method, or the like.

In S1709, the control device 50 forms the color filter substrate 131. In forming the color filter substrate 131, first, a transparent upper substrate 130 is prepared. Next, on the surface of the upper substrate 130, the material of the color filter layer 128 (for example, G) containing the ultraviolet curable resin component as a main component is dispersed in a solvent, a paste is applied, the solvent is removed to a certain extent, and then a predetermined pattern is obtained. Place the mask and irradiate with ultraviolet rays. Then, curing is performed to remove the pattern mask and the uncured paste and developed to form a color filter layer (G). By repeating this step in the same manner for the color filter materials of each color, the color filter layers (R) and (B) are formed. Instead of using the paste, a commercially available color filter product may be used. Further, the color filter substrate 131 may be formed in advance, and the formed color filter substrate 131 may only be installed in this step.

In S1710, the control device 50 bonds the color filter substrate 131 and the back panel. In this step, first, the material of the bonding layer 127 containing an ultraviolet curable resin such as an acrylic resin, a silicone resin, and an epoxy resin as a main component is applied to a back panel composed of each layer from the substrate 100 to the sealing layer 126. Subsequently, the applied material is irradiated with ultraviolet rays, and both substrates are bonded together in a state where the relative positional relationship between the back panel and the color filter substrate 131 is matched. At this time, the bonding is performed so that gas does not enter between the two. After that, both substrates are fired to complete the sealing step, thereby completing the display panel D. Then, this operation flow is terminated.

(Layer formation)
FIG. 18 shows a processing flow at the time of layer formation using the inkjet apparatus 1 performed in each of the steps S1703 to S1705 of FIG. Here, it is assumed that each layer is formed by the same operation. For the sake of simplicity, the following operation flow will be described as being comprehensively controlled by the control device 50.

In S1801, the control device 50 controls the ink ejection head 23 and the stage 40 to apply ink on the base material B. The operation here is executed by performing the control as shown in FIGS. 5 to 11. Further, as the ink used in this step, the ink corresponding to the layer to be formed shall be used. For example, in the case of the light emitting layer 123, it is formed corresponding to each of a plurality of colors (for example, three colors of R, G, and B) reproduced by the organic EL light emitting panel. The arrangement of the light emitting layer 123 corresponding to each color on the substrate 100 is defined in advance, and the formation is performed according to the arrangement. The formation order and arrangement of the light emitting layer 123 corresponding to each color are not particularly limited, and any setting may be used. A layer is formed by one or a plurality of ink droplets in a range corresponding to one pixel on the base material B.

In S1802, the control device 50 conveys the base material B and carries it into the drying device 60. At this time, as shown in FIGS. 12 and 13, the drying suppressing plate F is moved in conjunction with the movement of the base material B (stage 40).

In S1803, the control device 50 executes the drying operation of the base material B carried into the drying device 60. Details of this step will be described later with reference to FIG.

In S1804, after the drying operation of S1803 is completed, the control device 50 causes the baking process of the base material B to be executed by the baking device (not shown). The substrate B may be transported from the drying device 60 to the baking device (not shown) using a separately provided transport device (not shown). Baking completes layer formation. The baking process may be performed by a firing step under predetermined conditions (for example, a step of vacuum firing under the conditions of a heating temperature of about 230 ° C. and a heating time of about 60 minutes). The conditions here may differ depending on the configuration and function of the layer to be formed. Then, this processing flow is terminated. The baking treatment of the base material B is not an essential configuration, and may be configured so that the baking treatment is not performed depending on the material of the layer to be formed. The baking treatment of the base material B here is a baking treatment (firing treatment) of the film applied to the base material B.

(Drying ink)
The ink drying step according to this embodiment will be described. As described above, the drying device 60 according to the present embodiment is a vacuum dryer that dries the target by reducing the pressure. Further, as described with reference to FIGS. 12 and 13, the drying apparatus 60 according to the present embodiment can handle both the case where the drying suppressing plate F is carried in and the case where the drying suppressing plate F is not carried in. In the above example, it has been described that the light emitting layer 123, the hole injection layer 120, and the hole transport layer 121 can be formed by using an inkjet method among a plurality of layers constituting the display panel D. Which of the configurations of FIGS. 12 and 13 is applied may be specified for each layer.

When only the base material B is carried into the drying device 60 as shown in FIG. 12, the drying operation is performed by the drying device 60 in the state shown in FIG. After the base material B is carried in, the gas (steam) in the chamber 63 is discharged by the vacuum pump 62 and the pressure is reduced. As a result, the ink droplet K on the base material B is dried. After a certain period of time, the pressure in the chamber 63 is returned to the atmospheric pressure, the base material B is carried out, and the drying step is completed. The drying time is not particularly limited, and may be specified according to the size of the base material B, the composition of the ink, and the like. In the case of the configuration of FIG. 12, this operation is performed in the process of S1803 of FIG.

Next, as shown in FIG. 13, a drying operation when the base material B and the drying suppressing plate F are carried into the drying apparatus 60 will be described. FIG. 19 is a schematic view for explaining the operation of the drying device 60 corresponding to the configuration in which the drying suppressing plate F is carried in during the drying step. In FIG. 19, the flow of gas (steam) is indicated by an arrow. FIG. 19A shows a state at the time when the drying operation is started, and it is assumed that the distance between the drying suppressing plate F and the base material B is the same as the distance d during transportation shown in FIG. FIG. 19B shows a state when the pressure of the chamber 63 reaches a constant value after the drying operation is started. In this case, the position of the drying suppressing plate F is controlled so that the distance d between the drying suppressing plate F and the base material B increases in the Z-axis direction. Here, it is assumed that the drying suppressing plate F and the base material B are separated from each other up to the distance d _max that can be most separated in the chamber 63. The distance d _max may be defined according to the size of the chamber 63 and the like. Further, the drying device 60 is provided with a separation mechanism (not shown) capable of controlling the distance between the drying suppressing plate F and the base material B in the chamber 63. At this time, the distance d may be adjusted by moving at least one of the drying suppressing plate F and the support base 61.

Then, the gas (steam) in the chamber 63 is discharged by the vacuum pump 62, and the pressure is reduced. As a result, the ink droplets K on the base material B are dried, and after a certain period of time, the drying step is completed. The drying time is not particularly limited, and may be specified according to the size of the base material B, the composition of the ink, and the like.

FIG. 20 is a flowchart showing a drying process corresponding to the configuration of FIG. This processing flow is performed in the process of S1803 of FIG. 18 in the case of the configuration of FIG. For the sake of simplicity, the following operation flow will be described as being comprehensively controlled by the control device 50.

In S2001, the control device 50 carries the ink-coated base material B and the drying suppression plate F into the drying device 60 in a state of facing each other at a predetermined distance d. This is as shown in FIG.

In S2002, the control device 50 operates the vacuum pump 62 of the drying device 60 to start depressurization in the chamber 63. The speed of depressurization here is not particularly limited, and any setting may be used. The control device 50 starts measuring the time with the start of depressurization.

In S2003, the control device 50 determines whether or not the atmospheric pressure in the chamber 63 has reached the predetermined atmospheric pressure P1. The predetermined pressure P1 here is not particularly limited, but in the present embodiment, P1 is set in the range of 101325 Pa (atmospheric pressure) to 10000 Pa. FIG. 21 is a diagram showing the relationship between the change in atmospheric pressure and the elapsed time during the drying operation by the drying device 60 according to the present embodiment. In FIG. 21A, the vertical axis represents pressure [Pa] and the horizontal axis represents time [sec]. At the beginning of the drying operation, the pressure is 101325 Pa, which is the atmospheric pressure (standard pressure), and the pressure is reduced with the passage of time. FIG. 21B is a graph showing some values taken out from the graph shown in FIG. 21A. When the atmospheric pressure in the chamber 63 reaches a predetermined atmospheric pressure P1 set from within the above range (YES in S2003), the process of the control device 50 proceeds to S2004. On the other hand, when the atmospheric pressure in the chamber 63 has not reached the predetermined atmospheric pressure P1 (NO in S2003), the control device 50 continues the depressurizing operation and waits until the predetermined atmospheric pressure P1 is reached.

In the present embodiment, the distance d is not controlled immediately after the base material B is carried into the drying device 60, but the distance d is controlled at the timing when the atmospheric pressure reaches P1. When the distance d is adjusted, it is assumed that the airflow in the chamber 63 fluctuates, which affects the formation of the layer. Therefore, in the present embodiment, the distance d is controlled when the ink is dried to a certain degree and the shape of the layer is stabilized to some extent. This can improve the quality of layer formation.

In S2004, the control device 50 performs a separation operation between the base material B and the drying suppressing plate F in the chamber 63 by using a separation mechanism (not shown). Here, as shown in FIG. 19B, the distance between the base material B and the drying suppression plate F is increased to d _max .

In S2005, the control device 50 determines whether or not a predetermined time has elapsed from the start of depressurization in S2002. It is assumed that the predetermined time here is predetermined according to the composition of the ink, the size of the base material B, and the like. When the predetermined time has elapsed (YES in S2005), the process of the control device 50 proceeds to S2006. On the other hand, when the predetermined time has not elapsed (NO in S2005), the control device 50 continues the depressurizing operation and waits until the predetermined time elapses.

In S2006, the control device 50 stops the decompression operation by the vacuum pump 62 and returns the pressure in the chamber 63 to the atmospheric pressure. The return of the atmospheric pressure here may be configured to gradually return over a certain period of time, or may be configured to allow gas to flow in at once and return.

In S2007, the control device 50 carries out the base material B from the drying device 60. The carry-out here may be carried out using a carry-out device (not shown) provided separately. Further, the drying suppression plate F may be carried out from the drying device 60 together with the base material B, or may be configured to be carried out at another timing. Then, this processing flow is terminated.

In the examples of FIGS. 19 and 20, when the pressure in the chamber 63 reaches a predetermined atmospheric pressure P1, the distance d between the drying suppression plate F and the base material B is controlled to be expanded to the distance d _max at once. ing. However, the control is not limited to this, and for example, the distance may be gradually increased according to a change in pressure. Alternatively, the distance d may be adjusted (separated or brought closer) to a predetermined distance according to a change in pressure, an elapsed time, a change in drying conditions, or the like.

[Example of Embodiment]
Hereinafter, evaluation based on the film thickness formed will be described as an example of an embodiment using the method according to the present embodiment. Here, the first embodiment of the configuration corresponding to FIG. 12 of the present embodiment, the second embodiment of the configuration corresponding to FIG. 13 of the present embodiment, and the comparative embodiment example corresponding to the conventional configuration will be described. do. Further, here, a case where the hole injection layer in the display panel D is formed by an inkjet method will be taken as an example.

In this embodiment, the same ink is used in each case. As a charge transporting material which is a functional material constituting an ink, a functional polymer compound having a repeating structure of the following chemical formula M and a 4-isopropyl-4'-methyldiphenyliodonium tetrakis (pentafluoro) as an electron accepting compound. A mixture of phenyl) borate and 5: 1 can be used. Further, as the organic solvent constituting the ink, an organic solvent mixed at a ratio of cyclohexylbenzene: anisole = 2: 8 is used. Then, these functional materials (solutes) are dissolved in an organic solvent, and the organic solvent is prepared so as to be 2.0% by weight with respect to the entire ink.

The ink is applied in a predetermined coating region of the base material B, dried under reduced pressure, and then the hole injection layer 120 is generated, and the distribution of the film thickness thereof is measured. FIG. 22 is a schematic view showing a position where the film thickness is measured on the base material B2 in the present embodiment. In the present embodiment, as shown by the arrow in FIG. 22, the end along the Y axis at the center position in the X direction in the ink application region (corresponding to the self-luminous region 100a in FIG. 15) of the base material B. Measure the film thickness from the part to the end. The measured length from one end to the other here is, for example, 270 mm. Further, the target value of the film thickness is 60 nm. Further, the configuration examples of the first embodiment, the second embodiment, and the comparative embodiment at the time of layer formation are as follows.

(Embodiment Example 1)
The first embodiment corresponds to the configuration of FIG. The distance d between the lower surface of the drying suppression plate F and the upper surface of the base material B is fixed at 5 mm. Immediately before the base material B after the ink is applied is carried into the drying device 60, the opposition to the drying suppressing plate F is released, and only the base material B is carried into the drying device 60 to perform vacuum drying.

(Embodiment Example 2)
The second embodiment corresponds to the configuration of FIG. The distance d between the lower surface of the drying suppression plate F and the upper surface of the base material B is fixed at 5 mm. While maintaining the distance d between the base material B and the drying suppression plate F after the ink is applied, the ink is carried into the drying apparatus 60 to start vacuum drying. After that, when the pressure in the chamber 63 reaches a predetermined atmospheric pressure P1 during the depressurization operation, the drying suppression plate F is raised to 50 mm to perform decompression drying. That is, the distance d _max is 50 mm. In the second embodiment, the predetermined pressure P1 is set to 3 × 10 ⁴ Pa, which is in the range of 101325 Pa (atmospheric pressure) to 10000 Pa shown in FIG. 21 (a).

(Example of comparative form)
The comparative embodiment corresponds to the configuration without the drying suppression plate F according to the present embodiment. A layer is formed on the base material B without the drying suppression plate F, and the layer is transported to and carried into the drying apparatus 60, and then dried under reduced pressure.

(effect)
FIG. 23 shows a schematic diagram of the film thickness distribution after drying estimated in the above-mentioned first embodiment, second embodiment, and comparative example. In FIG. 23, the vertical axis indicates the film thickness [nm] of the formed layer, and the horizontal axis indicates the measurement position [mm] on the base material B.

Referring to FIG. 23, in the comparative embodiment (dotted line) not provided with the drying suppression plate F according to the present embodiment, the film thickness is significantly larger than the target value of 60 nm at both ends (around 0 mm and around 270 mm). It is expected to decrease. Further, it is considered that the film thickness is not stable with respect to the target value of 60 nm of the film thickness at other positions, and large waviness with unevenness occurs.

On the other hand, in the first embodiment (solid line) corresponding to the configuration according to the present embodiment, the drying by the volatilization of the solvent starts immediately after the opposition to the drying suppressing plate F is released, and the drying under reduced pressure is started. The solvent volatilizes to some extent. At this time, it is considered that the air flowing into the base material B from the outside of the base material B and the volatile solvent are mixed at both ends, the solvent vapor is diluted, the solvent volatilizes quickly, and the airflow is disturbed. It is considered that the liquid level shape is not stable. Therefore, it is considered that the film thickness is slightly reduced with respect to the target value at both ends (around 0 mm and around 270 mm), but the film thickness is considered to be closer to the target value as compared with the comparative form example. In addition, it is considered that the value close to the target value of the film thickness is also obtained at other positions. That is, it is considered that the first embodiment is improved as compared with the comparative embodiment.

Further, in the second embodiment (broken line) corresponding to the configuration according to the present embodiment, it is considered that the film thickness becomes uniform at a value close to the target value over the entire area including both ends. That is, it is considered that the accuracy of film formation is further improved in the second embodiment as compared with the first embodiment.

In the comparative form example, it is considered that the ink is dried and the film thickness is reduced in the process of applying the ink to the transfer to the drying device. On the other hand, in the first embodiment and the second embodiment corresponding to the configuration according to the present embodiment, the drying suppressing plate F is arranged so as to face the base material B between the drying suppressing plate F and the base material B. The vapor pressure in the space of the ink increases and the evaporation of the ink solvent is suppressed. Therefore, the ink formed on the base material B is dried in the drying apparatus with a uniform film thickness, and the uniformity of the film thickness of the dried layer is improved.

As described above, according to the present embodiment, it is possible to suppress unintended drying of ink and improve the uniformity of the film thickness regardless of the location on the substrate when manufacturing the organic EL display panel. Further, even when a layer on the substrate is formed by a plurality of ink droplets, the difference in the progress of drying due to the difference in the ejection timing of each ink droplet is suppressed, and the film is formed regardless of the position on the substrate. The layers can be made uniform.

<Other embodiments>
In the first embodiment, as shown in FIGS. 12 and 13, after the ink is applied, the drying suppressing plate F moves in conjunction with the movement of the base material B (stage 40). The configuration of the drying suppression plate F is not limited to the above, and may be another configuration. Hereinafter, an example of another configuration will be described as another embodiment of the present invention.

FIG. 24 is a diagram showing an example of another configuration of the drying suppression plate F. 12 and 13 show an example of a configuration in which the drying suppression plate F moves in conjunction with the movement of the base material B on the downstream side in the transport direction (X-axis direction) from the ink ejection head 23. .. On the other hand, FIG. 24 shows the drying device 60 from a position adjacent to the ejection surface of the ink ejection head 23 along the conveying path of the base material B on the downstream side in the conveying direction (X-axis direction) from the ink ejection head 23. An example is shown in which the drying suppression plate F is installed until just before the carry-in position. Then, after the base material B is conveyed to the position of the end portion of the drying suppression plate F, the base material B is carried into the drying device 60 by the carry-in device (not shown). The state of being carried into the drying device 60 may be the same as in FIG.

FIG. 25 is a diagram showing an example of another configuration of the drying suppression plate F. 12 and 13 show an example of a configuration in which the drying suppression plate F moves in conjunction with the movement of the base material B on the downstream side in the transport direction (X-axis direction) from the ink ejection head 23. .. On the other hand, FIG. 25 shows a drying suppressing plate F from a position adjacent to the ejection surface of the ink ejection head 23 along the conveying path of the base material B on the downstream side in the conveying direction (X-axis direction) from the ink ejection head 23. Is installed. Further, a drying suppression plate Fa for carrying into the drying device 60 is installed at a position immediately before the carrying-in position to the drying device 60. After the base material B is transported to a position immediately before the carry-in position to the drying device 60, the base material B is carried into the drying device 60 in a state of facing the drying suppression plate Fa by the carry-in device (not shown). .. At this time, it is assumed that the distance d between the drying suppressing plate Fa and the base material B is the same as the distance d between the drying suppressing plate F and the base material B. The state of being carried into the drying device 60 may be the same as that of FIG. 13, and in this case, the drying operation may be performed with the configuration as described with reference to FIGS. 19 and 20. The materials of the drying suppression plate F and the drying suppression plate Fa may be the same or different.

Note that FIG. 25 shows a configuration in which the drying suppression plate F and the drying suppression plate Fa are not linked to the movement of the base material B during transportation by the stage 40. Not limited to this configuration, a part of the drying suppression plate F (for example, the drying suppression plate Fa) is configured to move along the X-axis direction in conjunction with the movement of the base material B as in FIG. There may be. Alternatively, a drying suppression plate F composed of a plurality of parts is installed along the transport direction (X-axis direction) of the base material B, and each part constituting the drying suppression plate F relays as the base material B moves. It may be interlocked so as to face the base material B while switching in order according to the method.

Further, in the present invention, one or more programs or applications for realizing the functions of the above-mentioned one or more embodiments are supplied to the system or device using a network or a storage medium, and the system or device is used in a computer. It can also be realized by the process of reading and executing the program by the processor of.

Further, it may be realized by a circuit (for example, ASIC (Application Specific Integrated Circuit) or FPGA (Field Programmable Gate Array)) that realizes one or more functions.

As described above, the present invention is not limited to the above-described embodiment, and can be modified or applied by those skilled in the art based on the mutual combination of the configurations of the embodiments, the description of the specification, and the well-known technique. It is also a matter of the present invention to do so, and it is included in the scope of seeking protection.

The organic EL panel manufacturing apparatus and the organic EL panel manufacturing method according to the present invention are widely used for manufacturing devices such as television sets, personal computers, mobile phones, and display panels in various electronic devices having display panels. can do. Further, it can be widely used for manufacturing electronic devices including a step of forming a functional layer by using an ink coating step.

1 ... Ink device 10 ... X-axis table 11 ... Y-axis table 12 ... X-axis guide rail 13 ... Y-axis guide rail 20 ... Carriage unit 21 ... Carriage support 22 ... Carriage 23 ... Ink ejection head 40 ... Stage 41 ... Stage times Dynamic mechanism 42 ... X-axis slider 50 ... Control device 60 ... Drying device 61 ... Support stand 62 ... Vacuum pump 63 ... Chamber 100 ... Substrate 119 ... Pixel electrode 120 ... Hole injection layer 121 ... Hole transport layer 122 ... Bank 123 ... Light emitting layer 124 ... Electron transport layer 125 ... Opposite electrode 126 ... Sealing layer 127 ... Bonding layer 128 ... Color filter layer 130 ... Upper substrate 131 ... Color filter substrate 201 ... Nozzle hole 202 ... Ink droplet B ... Base material F ... Drying Suppressor plate K ... Ink droplets

Claims (19)

It is a manufacturing device for organic EL display panels.
A transport unit that moves the board,
An ink ejection head for ejecting ink for forming a functional layer of the organic EL display panel, and an ink ejection head.
A manufacturing apparatus comprising: a drying suppressing member arranged so as to face the surface of the substrate on which ink is ejected by the ink ejection head. The manufacturing apparatus according to claim 1, wherein the drying suppressing member is provided on the moving direction side of the substrate of the ink ejection head. The manufacturing apparatus according to claim 2, wherein the drying suppressing member is provided adjacent to the ink ejection head on the moving direction side of the substrate. The invention according to any one of claims 1 to 3, wherein the drying suppressing member is arranged so as to face a range in which the ink-coated region on the surface of the substrate is moved by the transport portion. manufacturing device. The manufacturing apparatus according to any one of claims 1 to 4, wherein the drying suppressing member is formed in a plate shape. The manufacturing apparatus according to any one of claims 1 to 5, wherein the drying suppressing member is arranged so that the distance from the surface of the substrate is within a predetermined range. The production according to any one of claims 1 to 6, wherein the drying suppressing member is configured to move in a state of facing the surface of the substrate in conjunction with the movement of the substrate. Device. The manufacturing apparatus according to any one of claims 1 to 7.
A drying device for drying the substrate on which the ink is discharged is provided.
The drying suppressing member is arranged so as to face each other so that the distance from the surface of the substrate is within a predetermined range while being transported from a position adjacent to the ink ejection head to the drying device by the transport unit. A manufacturing system characterized by that. The manufacturing apparatus according to any one of claims 1 to 7.
A drying device for drying the substrate on which the ink is discharged is provided.
The drying suppressing member faces each other so that the distance from the surface of the substrate is within a predetermined range while being transported from a position adjacent to the ink ejection head to a drying position in the drying device by the transport unit. A manufacturing system characterized by being placed in a row. The manufacturing system according to claim 9, further comprising an adjusting portion for adjusting the distance between the drying suppressing member and the surface of the substrate in the drying device. The drying device is a vacuum dryer.
The tenth aspect of the present invention is characterized in that the adjusting unit is moved so that the air pressure at the time of drying is a predetermined value and the distance between the drying suppressing member and the surface of the substrate is a predetermined distance. Manufacturing system. It is a manufacturing method of an organic EL display panel.
Ink is ejected onto the substrate by the ink ejection head to form the functional layer of the organic EL display panel.
A manufacturing method comprising arranging a drying suppressing member so as to face the surface of the substrate on which ink is ejected by the ink ejection head. The manufacturing method according to claim 12, wherein the drying suppressing member is arranged so as to face a range in which a region of ink ejected on the surface of the substrate moves. The drying suppressing member is so that the distance from the surface of the substrate is within a predetermined range while being conveyed from the position adjacent to the ink ejection head to the drying apparatus for drying the substrate on which the ink is ejected. The manufacturing method according to claim 12 or 13, wherein the manufacturing method is arranged in. The drying suppressing member has a predetermined range of distance from the surface of the substrate while being conveyed from a position adjacent to the ink ejection head to a drying position in a drying apparatus for drying the substrate on which the ink is ejected. The manufacturing method according to any one of claims 12 to 14, wherein the manufacturing method is arranged so as to be inside. Has a drying process with a drying device,
The manufacturing method according to claim 14 or 15, wherein the distance between the drying suppressing member and the surface of the substrate is adjusted in the drying apparatus used in the drying step. The drying device is a vacuum dryer.
The 16th aspect of the present invention is characterized in that, during a drying operation by the drying device, the atmospheric pressure is moved to a predetermined value and the distance between the drying suppressing member and the surface of the substrate is adjusted to be a predetermined distance. The manufacturing method described. The manufacturing method according to claim 17, wherein when a predetermined condition is satisfied during the drying operation by the drying device, the distance between the drying suppressing member and the surface of the substrate is adjusted. An organic EL display panel manufactured by the manufacturing method according to any one of claims 12 to 18.

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