CN116615289A

CN116615289A - Method for measuring and adjusting amount of discharged ink, device for measuring and adjusting amount of discharged ink, system for manufacturing organic EL display panel, method for manufacturing organic EL display panel, ink, and organic EL display panel manufactured using ink

Info

Publication number: CN116615289A
Application number: CN202180081773.5A
Authority: CN
Inventors: 福田敏生
Original assignee: Mitsubishi Chemical Corp
Current assignee: Mitsubishi Chemical Corp
Priority date: 2020-12-07
Filing date: 2021-12-03
Publication date: 2023-08-18
Also published as: JPWO2022124242A1; WO2022124242A1; KR20230117124A; TW202235170A

Abstract

A measurement adjustment method at least includes a measurement method for measuring the amount of ink discharged from an ink jet head, wherein the measurement method is configured to discharge ink from the ink jet head onto a substrate, obtain an image of the ink discharged onto the substrate, derive the amount of ink discharged from the ink jet head based on information obtained from the image, and maintain a constant ratio of the amount of ink discharged from the ink jet head to the amount of ink discharged from the ink jet head after a predetermined time has elapsed after the ink is discharged from the ink jet head.

Description

Method for measuring and adjusting amount of discharged ink, device for measuring and adjusting amount of discharged ink, system for manufacturing organic EL display panel, method for manufacturing organic EL display panel, ink, and organic EL display panel manufactured using ink

Technical Field

The present invention relates to a method for measuring and adjusting the amount of ink discharged by an ink jet head, an ink discharge amount measuring and adjusting device, a panel manufacturing system for an organic EL display panel, a method for manufacturing an organic EL display panel, an ink, and an organic EL display panel manufactured using the ink.

Background

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

In recent years, inkjet devices are used for manufacturing large-screen color filters, organic EL display panels, and the like. One of the processes for manufacturing an organic EL display panel is a process for forming an organic EL film, and an inkjet printing technique is used in the process. It is known that when a color filter or an organic EL display panel is manufactured, if there is a variation in the amount of ink discharged (arranged) on a substrate, the formed film thickness varies, and this causes uneven light emission in the organic EL display panel. Therefore, in order to manufacture an organic EL display panel with good accuracy, it is necessary to control the discharge amount of ink for each nozzle.

In patent document 1, the discharge weight of each ink jet head is measured by discharging liquid droplets to a weight measuring balance, and based on the measurement result, control is performed so that the discharge weight of each ink jet head becomes uniform. In patent document 2, the thickness of the ejected liquid droplet is measured, and the ejection pattern is changed based on the measured thickness, thereby adjusting the ejection weight. In patent document 3, the liquid droplet is irradiated with light from the annular illuminator in a state where the optical axis of the observation optical system is aligned with the center of the annular illuminator, and the height of the liquid droplet is measured based on an image obtained by capturing a virtual image of the annular illuminator generated from the liquid droplet by irradiation of light with the observation optical system. Patent document 4 discloses the following technique: the landing diameter of the droplet of each nozzle is measured based on image data of the droplet formed by evaporation of the solvent. In patent document 4, in order to prevent a change in volume due to evaporation of liquid droplets from landing to measurement, a cover for preventing evaporation is used.

Prior art literature

Patent literature

Patent document 1: japanese patent application laid-open No. 2004-209429

Patent document 2: japanese patent laid-open No. 2006-34231

Patent document 3: japanese patent application laid-open No. 2010-169413

Patent document 4: japanese patent laid-open publication No. 2019-169413

Disclosure of Invention

On the other hand, in the measurement method of patent document 1, since a large amount of ink is required and a large amount of time is required for the measurement, the operation rate of the inkjet device is greatly reduced. In the method of patent document 2, there is no device for calculating the discharge weight of the discharged liquid droplets for each nozzle, and there is a concern that the discharge weight of each ink jet head is not uniform. In addition, when the technique described in patent document 3 is combined with, for example, an inkjet device, it is difficult to say that it is sufficient to accurately measure finer droplets in the development of high definition. Further, since minute droplets of an organic EL material or the like are liable to change in droplet volume due to evaporation of a solvent, a technique for accurately obtaining the droplet volume in consideration of such volume change is required. The method for measuring the amount of liquid droplets described in patent document 4 uses a cover and its arrangement mechanism for preventing evaporation. Such a mechanism is constituted in a large scale as a whole.

The present application has been made to solve the above-described problems, and an object of the present application is to accurately measure the amount of discharged liquid droplets without an evaporation prevention mechanism, in order to solve the problem that the amount of liquid droplets is easily changed by evaporation of a solvent.

In order to solve the above problems, the present application has the following configuration. That is, a measurement adjustment method includes at least a measurement method for measuring the discharge amount of ink from an ink jet head,

the above measurement method comprises:

a discharge step of discharging ink from the ink jet head onto a substrate,

an acquisition step of acquiring an image of ink ejected onto the substrate, and

a deriving step of deriving a discharge amount of ink from the ink jet head based on information obtained from the image;

after a predetermined time has elapsed from the ejection of the ink from the ink jet head, the amount of the ink ejected onto the substrate is maintained at a predetermined ratio to the amount of the ink ejected from the ink jet head.

In one embodiment of the present application, the measurement and adjustment method further includes a drying step of drying the ink discharged onto the substrate during the predetermined time period,

After the drying step, the obtaining step is performed.

In one embodiment of the present application, the ink contains a solvent and a functional material,

the solvent contains an organic solvent having a boiling point of 250 ℃ or higher.

In addition, another embodiment of the present application has the following configuration. That is, a measurement adjustment method includes at least a measurement method for measuring the discharge amount of ink from an ink jet head,

the above measurement method comprises:

a discharge step of discharging ink from the ink jet head onto a substrate,

the ink described above contains a solvent and a functional material,

In one embodiment of the present application, the measurement and adjustment step further includes a drying step of drying the ink discharged onto the substrate during a predetermined period of time,

after the drying step, the obtaining step is performed.

In one embodiment of the present application, the predetermined time is 5 minutes or longer.

the solvent contains an organic solvent having a boiling point of 300 ℃ or higher.

In one embodiment of the present application, the organic solvent is contained in an amount of 20 wt% or more relative to the ink.

In one embodiment of the present application, the base material is coated with a liquid-repellent coating material having liquid repellency to the ink.

In one embodiment of the present application, in the deriving step,

the diameter of the drop of ink is extracted from the image,

deriving the volume of ink on the substrate using at least the extracted diameter,

and deriving the discharge amount of the ink from the ink jet head from the derived volume of the ink on the substrate.

In one embodiment of the present application, the measurement adjustment method further includes the following adjustment steps: and adjusting the discharge amount from the ink jet head based on the discharge amount of the ink derived in the deriving step.

In one embodiment of the present application, the measurement adjustment method is used when forming at least one of the light-emitting layer, the hole injection layer, and the hole transport layer among the functional layers constituting the organic EL display panel.

In addition, another embodiment of the present application has the following configuration. That is, an ink ejection amount measurement and adjustment device uses the measurement and adjustment method described above.

In addition, another embodiment of the present application has the following configuration. That is, a panel manufacturing system of an organic EL display panel includes the above-described ink discharge amount measurement and adjustment device.

In addition, another embodiment of the present application has the following configuration. That is, a method for manufacturing an organic EL display panel uses the above measurement adjustment method.

In addition, another embodiment of the present application has the following configuration. Namely, a method for manufacturing an organic EL display panel, using the above panel manufacturing system.

In addition, another embodiment of the present application has the following configuration. Namely, an ink used in the above measurement adjustment method,

comprising a solvent and a functional material corresponding to the functional layer,

In addition, another embodiment of the present application has the following configuration. That is, an ink used in the ink discharge amount measurement and adjustment device,

In addition, another embodiment of the present application has the following configuration. Namely, an ink used in the panel manufacturing system of the organic EL display panel,

In one embodiment of the present application, the ink is dried for a predetermined period of time, and then a certain proportion of the ink is maintained with respect to the volume before the drying.

In addition, another embodiment of the present application has the following configuration. That is, an organic EL display panel has a functional layer formed using the ink.

According to the present application, the measurement and/or adjustment of the amount of discharged liquid droplets can be accurately performed with a simple configuration.

Drawings

Fig. 1 is a schematic diagram showing an example of the structure of an inkjet device according to an embodiment of the present application.

Fig. 2 is a schematic diagram showing an example of the structure of an inkjet device according to an embodiment of the present application.

Fig. 3 is a diagram for explaining ejection of an ink jet head according to an embodiment of the present application.

Fig. 4 is a graph for explaining the characteristics of the ink according to the embodiment of the present application.

Fig. 5 is a table diagram for explaining the characteristics of the ink according to the embodiment of the present application.

Fig. 6 is a flowchart of an ink discharge amount measurement adjustment process according to an embodiment of the present application.

Fig. 7 is a diagram for explaining an ink ejection process according to an embodiment of the present application.

Fig. 8 is a diagram for explaining a process of obtaining ink droplets according to an embodiment of the present application.

Fig. 9A is a diagram for explaining an ink discharge state according to an embodiment of the present application.

Fig. 9B is a diagram for explaining an ink discharge state according to an embodiment of the present application.

Fig. 10 is a plan view showing an exemplary configuration of a display panel according to an embodiment of the present application.

Fig. 11 is a plan view showing an exemplary configuration of a display panel according to an embodiment of the present application.

Fig. 12 is a cross-sectional view showing an example of the structure of a display panel according to an embodiment of the present application.

Fig. 13 is a flowchart of a panel manufacturing process of a display panel according to an embodiment of the present application.

Fig. 14A is a table diagram for explaining test results of a method according to an embodiment of the present application.

Fig. 14B is a table diagram for explaining test results of a method according to an embodiment of the present application.

Fig. 15 is a diagram for explaining a test of an embodiment of the present application.

Fig. 16 is a graph for explaining test results of a method according to an embodiment of the present application.

Fig. 17 is a table diagram for explaining test results of a method according to an embodiment of the present application.

Detailed Description

Hereinafter, modes for carrying out the present application will be described with reference to the drawings. The following embodiments are described for explaining one embodiment of the present application, and are not intended to limit the present application, and all the configurations described in the embodiments are not limited to those necessary for solving the problems of the present application. In the drawings, the same reference numerals are given to the same constituent elements, and the correspondence relationship is indicated.

Embodiment 1

[ device configuration ]

An example of the structure of an inkjet device according to an embodiment of the present application will be described with reference to fig. 1 and 2. Fig. 1 and 2 show an ink ejection amount measurement and adjustment device from an ink jet head, which is capable of performing the steps of measuring and adjusting the amount of ink ejected from the ink jet head, which will be described later, of the ink jet device according to the present embodiment. Fig. 1 is a schematic side view schematically showing the structure of an inkjet device 1 according to the present embodiment. Fig. 2 is a schematic plan view schematically showing the structure of the inkjet device 1 according to the present embodiment. Hereinafter, the main scanning direction of the stage 40 (i.e., the conveyance direction of the substrate) is referred to as an X-axis direction, the sub-scanning direction orthogonal to the main scanning direction is referred to as a Y-axis direction, and the vertical direction orthogonal to the X-axis direction and the Y-axis direction is referred to as a Z-axis direction. Further, the rotational direction around the Z-axis direction is defined as θ direction. In each figure, each axial direction is described correspondingly.

The inkjet device 1 includes: an X-axis table 10 extending in the main scanning direction (X-axis direction), and a pair of Y-axis tables 11 extending in the sub-scanning direction (Y-axis direction) and being bridged so as to span the X-axis table 10. On the upper surface of the X-axis table 10, a pair of X-axis guide rails 12 are provided so as to extend in the X-axis direction, and an X-axis linear motor (not shown) is provided on the X-axis guide rails 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 cradle unit 20 and a camera unit 30 are provided on the pair of Y-axis tables 11.

(bracket Unit)

The carriage unit 20 includes a carriage support 21, a carriage 22, and an ink jet head 23. On the lower surface of the carriage unit 20, 1 or more carriages 22 and 1 or more ink ejection heads 23 are provided in accordance with the type of ink to be ejected. In the present embodiment, for example, a plurality of ink ejection heads 23 having a line head type structure corresponding to the substrate width are provided in the Y-axis direction. A plurality of nozzles are formed on the lower surface of the ink jet head 23, that is, the ink discharge surface, and droplets of ink are discharged from the nozzles. For example, when 3 kinds of inks corresponding to 3 colors of R (Red), G (Green), and B (Blue) are ejected, 3 columns of ink ejection heads 23 are provided. The number of types of ink that can be used in the ink jet device 1 is not particularly limited, and may be increased or decreased depending on the structure of the product. A supply unit (not shown) for supplying ink is connected to the carriage unit 20, and ink is supplied at a proper timing.

The carriage support 21 is attached to the Y-axis rail 13, and is configured to be movable in the Y-axis direction by a Y-axis linear motor (not shown) provided to the Y-axis rail 13. For example, the bracket unit 20 may be constituted as follows: as shown in fig. 2, the ink jet head moves so as to be positioned on the X-axis table 10 during ink discharge, and moves along the Y-axis guide rail 13 to the retracted position during cleaning of the ink jet head 23, thereby performing a cleaning operation. Examples of the cleaning operation include preliminary ejection of ink, wiping of the ejection surface of the ink ejection head 23, and the like.

Fig. 3 is a diagram schematically showing a state in which ink droplets 202 are ejected from the ink ejection head 23. The ink jet head 23 of the present embodiment shows an example using a piezoelectric system. In the piezoelectric system, a driving voltage is applied to a piezoelectric element (not shown) located inside the ink jet head 23 to expand and contract the piezoelectric element, thereby ejecting a predetermined amount of ink droplets 202 from fine holes called nozzle holes 201. The ejected ink droplets 202 land on the substrate B disposed 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. 3.

(Camera unit)

The camera unit 30 captures an image of the substrate B mounted on the stage 40, and acquires an image including the substrate B and the ink droplets 202 ejected thereon. The camera unit 30 includes a camera 31 as an imaging unit.

As shown in fig. 1, the camera 31 is provided on one side of the Y-axis tables 11 of the pair of Y-axis tables 11, and is supported by the camera support portion 32. In the example of fig. 1, the camera 31 is provided on the downstream side of the ink jet head 23 in the transport direction (X-axis direction) of the substrate B. The camera support portion 32 is provided with a movement mechanism (not shown) for moving the camera 31, and the camera 31 is movable in the Y-axis direction. The cameras 31 are provided corresponding to the carriage unit 20 (carriage 22), for example, and may be provided in plurality along the Y-axis direction. Therefore, a plurality of cameras 31 may be provided in order to shorten the time of the photographing operation. The camera 31 of the present embodiment has a function of capturing an image capable of reproducing the resolution of each ink droplet 202 ejected onto the substrate B. In the case of photographing by the camera 31, the substrate B may be irradiated with illumination light from an illuminator (not shown). As a light source of the illuminator (not shown), for example, an LED (light emitting diode ) or the like can be used.

(stage)

The stage 40 is, for example, a vacuum chuck stage, and can chuck and fix the substrate B. In the present embodiment, the substrate B corresponds to a substrate for measuring the ejection amount of ink and a substrate for forming a pixel pattern. When it is necessary to describe each substrate, the subscripts are shown as a substrate B1 for measuring the discharge amount of ink and a substrate B2 for forming a display panel, and when the descriptions are collectively shown as a substrate B. The substrate B1 is coated with a liquid-repellent coating material on the ink-jet surface, and is liquid-repellent to ink. The liquid-repellent coating material herein defines its composition according to the composition of the ink.

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 to the X-axis guide rail 12.

As will be described later in detail, the display panel that can be manufactured using the inkjet device 1 of the present embodiment is composed of a plurality of layers. These layers comprise 1 or more layers that can be formed by inkjet. Therefore, when these layers are formed separately, a plurality of the structures shown in fig. 1 and 2 can be provided and applied. Since the types of inks used in the respective layers are different, the base material B1 for measuring the carriage unit 20 and the like, forming a necessary mechanism, and measuring the amount of ink discharged can be provided in accordance with the functions of the respective layers.

(control device)

The inkjet device 1 includes a control device 50. The control device 50 may be implemented by an information processing device including a control unit, a storage unit, and an output unit, which are not shown, for example. The control section may be constituted by a CPU (central processing unit ), an MPU (micro processing unit, micro Processing Unit), a DSP (digital signal processor, digital Single Processor), a dedicated circuit, or the like. The storage unit is configured by a volatile or nonvolatile storage medium such as an HDD (Hard Disk Drive), a ROM (Read Only Memory), a RAM (random access Memory), and the like, and can input and output various information in accordance with an instruction from the control unit. The storage unit stores a program for realizing the processing according to the present embodiment. The output unit is configured by a display device such as a speaker, a lamp, or a liquid crystal display, and outputs various kinds of output in accordance with instructions from the control unit. The output method by the output device is not particularly limited, and may be, for example, visual output based on screen output. The output unit may be a network interface having a communication function, or may perform an output operation by transmitting data to an external device (not shown) via a network (not shown).

The control device 50 performs, for example, the positional control of the stage 40 and the carriage unit 20 and the discharge control of the ink by the ink jet head 23. During the ejection of ink, the control device 50 outputs a control signal to the ink ejection head 23 according to the image pattern formed. The control device 50 controls the photographing operation by the camera unit 30 in order to measure the ink discharge amount. In addition, the control device 50 performs various controls for generating the display panel D. In this embodiment, an organic EL display panel is exemplified as the display panel D.

[ Properties of ink ]

The characteristics of the ink of the present embodiment will be described. The ink used in the production of the organic EL display panel is exemplified as the ink of the present embodiment, but the ink is not limited to this as long as it is used in the production of the product to which the ink jet device 1 can be applied. In the manufacture of organic EL display panels, it is required to adjust the discharge amount of ink with high accuracy. In such adjustment, it is necessary to measure the amount of ink ejected from each nozzle, but it is difficult to accurately measure the amount of ink ejected due to a volume change caused by ink drying. In contrast, in the present embodiment, an ink having a composition that is characteristic in terms of the tendency of change in volume due to drying is used.

The ink is composed of a solute containing a functional material and a solvent containing an organic solvent. The functional material is used to realize the function of a layer formed by an inkjet method among layers constituting the organic EL display panel. The organic solvent needs to be an organic solvent in which a solution containing a functional material can be dissolved or dispersed.

Fig. 4 and 5 are diagrams for explaining the characteristics of the ink according to the present embodiment. Here, an ink (example) according to the present embodiment and an ink (comparative example) for comparison will be described.

The ink of the present embodiment has a characteristic that the volume after drying is stable after a lapse of a predetermined time, as compared with the conventional ink. Fig. 4 is a graph showing changes in volume of droplets with time of the ink of the present embodiment and the comparative example. In fig. 4, the horizontal axis represents the time [ min ] for which an ink droplet is discharged, and the vertical axis represents the volume [ pl ] of the ink droplet. The initial example was the same volume as the ink droplets of the comparative example.

In the example of fig. 4, in the case of the comparative example, the volume of the ink droplet decreases with the lapse of time, and the time when the standing time passes for 10 minutes is approximately 0. On the other hand, in the case of the example, the volume of the ink droplet decreases with the lapse of time, but the volume change substantially disappears after a lapse of a certain standing time, and the volume is maintained substantially constant. As indicated by the arrows in fig. 4, the volume reduction substantially disappeared and the volume was constant after the lapse of 5 minutes for the example. Fig. 5 shows the value of the volume for each elapsed time (placement time) corresponding to fig. 4. The volume of each of the examples and comparative examples decreased in approximately the same trend until a certain standing time had elapsed. Then (after 5 minutes) the reduced trend was different. In short, the ink of the present embodiment has the following characteristics: after a certain standing time (i.e., a drying time), the evaporation of the solvent substantially disappears, and the change in volume of the ink is suppressed and stabilized. The stabilization of the ink by suppressing the change in volume means that the ink volume change substantially disappears by the evaporation of the solvent from the ink, and a state in which a certain amount is maintained. In the present embodiment, the state in which the constant amount is maintained may be, for example, a state in which the volume reduction rate is 0.01pl/min or less.

It is assumed that the volume of the ink stabilized by suppressing the volume change is 1.00pl, for example. Here, when an acquisition step of acquiring an image of ink ejected onto the substrate B is performed after ink is ejected from the ink ejection head 23, the time from the ink ejection step to the acquisition step fluctuates for some reason. Even if a variation of 1 minute occurs, the volume change is 1% or less (back) and such a characteristic is preferable in terms of manufacturing an organic EL panel. From the viewpoint of improving the accuracy of the amount of ink discharged from the ink jet head 23, it is more preferably 0.005pl/min or less, and particularly preferably 0.001pl/min or less. ( (-) when the volume of the ink of 1.00pl was reduced by 0.01pl/min, the reduction in volume was 0.01pl in 1 minute. It is 1% of 1.00pl )

In order to achieve the above-described characteristics, the composition of the ink according to the present embodiment is determined. As described above, the ink is composed of a solvent and a solute. Examples of the organic solvent that can be used in the present embodiment include aliphatic hydrocarbon compounds, aliphatic alcohol compounds, aliphatic ether compounds, aliphatic diol compounds, aliphatic ester compounds, aliphatic aldehyde compounds, aliphatic ketone compounds, aliphatic carboxyl compounds, aliphatic compounds containing a nitrogen atom, aliphatic compounds containing a sulfur atom, alicyclic compounds having a heteroatom, aromatic hydrocarbon compounds, aromatic alcohol compounds, aromatic ester compounds, aromatic ether compounds, aromatic aldehyde compounds, and aromatic carboxyl compounds.

In the case of specific examples, examples of the aliphatic hydrocarbon compound include n-octane, nonane, n-decane, and n-undecane. Examples of the aliphatic alcohol-based compound include 1-butanol, 1-pentanol, 2-pentanol, 1-hexanol, 2-hexanol, 1-heptanol, 2-heptanol, 1-octanol, 2-nonanol, n-dodecane, n-tridecane, n-tetradecane, 1-nonanol, n-dodecanol, 2-decanol, n-undecanol, and isodecanol.

Examples of the aliphatic ether-based compound include dibutyl ether (boiling point 137 to 143 ℃), and the like.

Examples of the aliphatic diol compound include ethylene glycol, ethylene glycol monoethyl ether, ethylene glycol diethyl ether, ethylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monomethyl ether, hexylene glycol, diethylene glycol, triethylene glycol dimethyl ether, ethylene glycol mono-2-ethylhexyl ether, ethylene glycol monobutyl ether, ethylene glycol monohexyl ether, ethylene glycol monobenzyl ether, dipropylene glycol, 1, 3-butanediol, 1, 4-butanediol, neopentyl glycol, and 1, 5-pentanediol.

Examples of the aliphatic ester compound include n-butyl formate, allyl acetate, n-butyl acetate, dimethyl succinate, diethyl oxalate, dimethyl oxalate, methyl lactate, ethyl lactate, methyl pyruvate, ethyl pyruvate, dimethyl malonate, diethyl malonate, and the like.

Examples of the aliphatic ester compound include n-octyl acetate and diethyl succinate.

Examples of the aliphatic aldehyde compound include furfural and the like.

Examples of the aliphatic ketone compound include methyl isobutyl ketone, diisopropyl ketone, and diisobutyl ketone.

Examples of the aliphatic carboxylic compound include formic acid, acetic acid, and propionic acid.

Examples of the aliphatic compound containing a nitrogen atom include N, N-dimethylacetamide, N-dimethylformamide, N-diisopropylethylamine, acetamide, and the like.

Examples of the aliphatic compound containing a sulfur atom include dimethyl sulfoxide and the like.

Examples of the alicyclic hydrocarbon compound include methylcyclohexane, dimethylcyclohexane, ethylcyclohexane, cycloheptane, decalin, cyclopentanol, cyclohexanol, methylcyclohexanol, dimethylcyclohexanol, cyclohexenol, cyclohexylmethanol, tetrahydrofurfuryl alcohol, furfuryl alcohol, cyclopentanone, cyclohexanone, and di-alcoholsAlkane, methylcyclohexanone, cyclohexylcyclohexane, and the like.

Examples of the alicyclic ketone compound include isophorone and the like.

Examples of the alicyclic lactone compound include gamma-butyrolactone and delta-valerolactone.

Examples of the aliphatic carbonate compound include propylene carbonate.

Examples of the alicyclic compound containing a nitrogen atom include N-methylpyrrolidone, 2-pyrrolidone, and 1, 3-dimethylimidazolidinone.

Examples of the alicyclic compound containing a sulfur atom include sulfolane and the like.

Examples of the aromatic hydrocarbon compound include toluene, o-xylene, p-xylene, m-xylene, mesitylene, 1,2, 4-trimethylbenzene, ethylbenzene, o-diethylbenzene, m-diethylbenzene, p-diethylbenzene, o-ethylmethylbenzene, p-ethylmethylbenzene, m-ethylmethylbenzene, n-propylbenzene, isopropylbenzene, n-butylbenzene, sec-butylbenzene, isobutylbenzene, tert-butylbenzene, n-pentylbenzene, n-hexylbenzene, n-heptylbenzene, 1, 3-diisopropylbenzene, 1, 4-diisopropylbenzene, cyclohexylbenzene, tetrahydronaphthalene, and the like.

Examples of the aromatic alcohol compound include phenol, o-cresol, o-ethylphenol, m-cresol, p-ethylphenol, 4-methoxyphenol, o-n-propylphenol, o-isopropylphenol, o-sec-butylphenol, o-tert-butylphenol, m-tert-butylphenol, p-tert-butylphenol, and benzyl alcohol.

Examples of the aromatic ester compound include methyl benzoate, ethyl benzoate, and n-butyl benzoate.

Examples of the aromatic aldehyde compound include benzaldehyde.

Examples of the aromatic carboxyl compound include benzoic acid.

The organic solvent contained in the ink of the present embodiment has a boiling point of 250 ℃. Examples of the organic solvent having such characteristics include aliphatic hydrocarbon compounds, aliphatic alcohol compounds, aliphatic ether compounds, aliphatic diol compounds, aliphatic ester compounds, aliphatic aldehyde compounds, aliphatic ketone compounds, aliphatic carboxyl compounds, aliphatic compounds containing nitrogen atoms, aliphatic compounds containing sulfur atoms, alicyclic compounds having heteroatoms, aromatic hydrocarbon compounds, aromatic alcohol compounds, aromatic ester compounds, aromatic ether compounds, aromatic aldehyde compounds, and aromatic carboxyl compounds.

Examples of the organic solvents having the above-mentioned characteristics include triethylene glycol (boiling point 287 ℃), tetraethylene glycol dimethyl ether (boiling point 275 ℃), diethylene glycol dibutyl ether (boiling point 254 ℃), ethylene glycol monobenzyl ether (boiling point 256 ℃), tripropylene glycol (boiling point 268 ℃), 1, 6-hexanediol (boiling point 250 ℃), thiodiglycol (boiling point 283 ℃), 2- (1-cyclohexenyl) cyclohexanone (boiling point 265 ℃), sulfolane (boiling point 285 ℃), n-octylbenzene (boiling point 261-263 ℃), n-nonylbenzene (boiling point 282 ℃), n-decylbenzene (boiling point 293 ℃), biphenyl (boiling point 255 ℃), dimethylnaphthalene (boiling point 261-287 ℃), n-butyl benzoate (boiling point 250 ℃), and phenylacetic acid (boiling point 266 ℃) as an aromatic carboxyl compound.

Further, as the organic solvent contained in the ink of the present embodiment, an organic solvent having a boiling point of 300 ℃ or higher may be used. Examples of the organic solvent having such characteristics include dodecylbenzene (boiling point 331 ℃), diphenyl carbonate (boiling point 302 ℃), benzyl benzoate (boiling point 324 ℃), dioctyl sebacate (boiling point 312 ℃), dibutyl sebacate (boiling point 349 ℃), dibutyl phthalate (boiling point 341 ℃), dioctyl phthalate (boiling point 361 ℃), nonylphenol (boiling point 303 ℃), p-benzylphenol (boiling point 320 ℃) and diphenyl sulfone (boiling point 379 ℃).

The ink composition of the present embodiment may contain 1 or more organic solvents having a boiling point of 250 ℃ or higher, and it is preferable to use a plurality of organic solvents in combination in consideration of adjustment of physical property values of the ink, and the like.

From the viewpoint of calculating the ejection amount from the image captured by the camera 31, the film forming property, and the like, the content of the organic solvent having a boiling point of 250 ℃ or higher contained in the ink composition of the present embodiment is preferably 20% by weight or higher relative to the weight of the composition. This is because, when the content of the organic solvent having the above-described characteristics is small, an error is likely to occur in the image capturing when the amount of ink discharged is measured.

The ink composition may further contain, in addition to the above-mentioned organic solvent, a surfactant for surface adjustment, an ultraviolet absorber for storage stability of the ink composition, a light stabilizer, an antioxidant, and other additives as appropriate.

The boiling point of the organic solvent contained in the ink composition of the present embodiment is 250 ℃ or higher, preferably 280 ℃ or higher, and more preferably 300 ℃ or higher. The upper limit is preferably 400℃or lower, more preferably 380℃or lower, and particularly preferably 350℃or lower. This is assumed to be the boiling point of the environment in which the display panel D is manufactured by the inkjet device 1 of the present embodiment. In short, the drying condition of the ink is assumed. Therefore, the type and boiling point temperature of the high-boiling point organic solvent used can be changed or adjusted according to the environment in which the inkjet device 1 is used (measurement environment).

The ink composition of the present embodiment containing an organic solvent having a boiling point of 250 ℃ or higher is preferably used as it is for manufacturing the display panel D. That is, it is preferable to manufacture the display panel D directly using the ink for adjusting the ink discharge amount from the ink jet head 23 of the ink jet device 1 to an appropriate discharge amount through the discharge step, the acquisition step, and the discharge step, because the ink discharge amount from the ink jet head 23 can be quickly transferred to the panel manufacturing step in a state where the ink discharge amount is the most appropriate discharge amount. When the ink to be ejected from the ink ejection head 23 of the ink jet device 1 is different from the ink to be used for manufacturing the panel, the ink ejection amount is adjusted to an appropriate amount by the ejection step, the acquisition step, and the lead-out step, a cleaning step and an ink replacement step are required to replace the ink. Therefore, there are the following problems: the time required for the panel manufacturing cost increases, or the ink ejection amount may deviate from the adjusted ejection amount due to the load applied to the nozzles of the inkjet device 1 by the cleaning process and the replacement process.

[ flow of the ejection amount measurement adjustment Process ]

The ejection amount measurement and adjustment step is performed by an ink ejection amount measurement and adjustment device having the ink jet device 1. The ejection amount measurement and adjustment step includes a measurement and adjustment method described below.

[ measurement adjustment method ]

The measurement adjustment method includes a measurement method for measuring a droplet size of ink ejected from the ink ejection head 23 described below. When the amount of droplets of the ink measured by the measurement method deviates from the appropriate value, an adjustment method for adjusting the amount to the appropriate value is required. Therefore, the measurement adjustment method of the present embodiment may include a measurement step of measuring the amount of ink discharged, and an adjustment step of adjusting the amount of ink based on the result measured in the measurement step.

[ measurement method ]

Next, a method for measuring the amount of ink discharged by the inkjet device 1 according to the present embodiment (hereinafter, also referred to as "measurement method") will be described. The measurement method according to the present embodiment is at least a necessary method for adjusting the amount of ink discharged by the inkjet device 1 according to the present embodiment. The measurement method according to the present embodiment is a method of measuring the amount of ink discharged from the ink jet head 23, and here, the amount of ink droplets discharged from the ink jet head 23 is not measured directly but is measured indirectly by the flow of a series of steps S602 to S605 below.

Fig. 6 is a flowchart showing an example of the flow of the ejection amount measurement adjustment step and the flow of the ejection amount adjustment step according to the present embodiment described below. The ejection amount measurement and adjustment step is composed of a plurality of steps as shown in fig. 6. The steps shown in fig. 6 may be started based on a user instruction or may be started based on predetermined operation conditions. In order to simplify the explanation, the flow of each step below will be described as a flow of overall control by the control device 50.

(insertion step)

When measuring the discharge amount of ink from the ink jet head 23, first, as an insertion step of the base material B1, the base material B1 is inserted to a predetermined start position. In S601, the control device 50 performs insertion of the substrate B1 for discharge amount measurement, while controlling the positions of the respective portions to the start positions of the main measurement steps described below. The starting position of the measurement process of the present embodiment is the position of the stage 40 shown in fig. 1. In this position, the substrate B1 can be inserted onto the stage 40. The ink jet head 23 is also located on the transport path of the substrate B1 as shown in fig. 2. The substrate B1 may be inserted into the stage 40 using a separate insertion device (not shown) or the like.

(ejection step)

The ejection step is a step of ejecting ink from the ink jet head 23 onto the substrate B1 and landing the ink on the substrate B1. In S602, as shown in fig. 7, the control device 50 moves the substrate B1 directly below the ink jet head 23, and ejects ink on the substrate B1. The discharge of the ink may be performed simultaneously in all of the plurality of ink ejection heads 23, or may be performed sequentially in a predetermined order. In addition, at the time of ejection, an ejection pattern in which all nozzles are ejected at the same time may be used, or a predetermined ejection pattern in which the nozzles are ejected sequentially may be used. As described above, since the surface of the base material B1 is coated with the liquid-repellent coating material, the ejected ink droplets 202 have a dome-like shape as shown in fig. 9A. Here, the ink droplet landed on the substrate B1 is denoted by K.

(drying step)

The drying step is a step of stabilizing the ink landed on the substrate B1 for a predetermined period of time so that the volume change caused by the drying of the organic solvent substantially disappears in the ejection step. In S603, the control device 50 performs drying of the ink droplets K on the substrate B1 shown in fig. 9A. As described above, the ink of the present embodiment is constituted by including an organic solvent (high boiling point solvent) which is not easily evaporated. Therefore, by providing a drying step for a certain period of time after landing on the substrate B1, the volume of the ink droplets K is stabilized after evaporation of the ink to some extent occurs. In the stabilized state, the diameter of the ink droplet K is not substantially changed. This state is a state in which the volume change of the ink substantially disappears and a proportional amount is maintained. By photographing the ink droplet K after stabilizing the volume of the ink in this way, the amount of ink droplet can be measured with good accuracy. The time required for the drying step may be determined according to the characteristics of the ink. For example, in the case of having the characteristics shown in fig. 4 and 5, the time required for the drying step is preferably 5 minutes or more, more preferably 10 minutes or more, in terms of a predetermined time. In addition, as shown in fig. 1, when a plurality of ink ejection heads 23 are provided and each corresponds to ink having a different composition, the drying time in the drying step in S603 is adjusted in accordance with the composition of each ink.

The drying step is not particularly limited as long as a predetermined time can be set up until the subsequent imaging step. For example, the substrate B1 may be dried while being stopped immediately below the ink jet head 23, or may be dried while being moved to the imaging position of the camera 31 for a predetermined time. Alternatively, the drying may be performed at the photographing position of the camera 31. In the present embodiment, the drying is natural drying, and no particular adjustment of temperature and humidity is performed, but at least measurement of the drying time during which the drying is performed.

(obtaining step)

The acquisition step is a step of acquiring an image of the ink discharged onto the substrate B1. In S604, the control device 50 moves the substrate B1 directly below the camera 31 as shown in fig. 8, photographs the substrate B1, and obtains an image including ink discharged onto the substrate B1. Fig. 8 is a schematic diagram showing a state of the base material B1 at the time of photographing. Fig. 9A is a view of the periphery of the camera 31 when photographing is seen from the side along the X-axis direction, and fig. 9B is a view of the base material B1 of the photographing object seen from the upper surface side along the Z-axis direction. Fig. 8, 9A and 9B show an example in which the ink droplets K are captured for every 1 line in the sub-scanning direction, but the present invention is not limited thereto. The ink droplets K of the plurality of rows may be collectively photographed according to the angle of view, resolution, and the like of the camera 31. From the viewpoint of shortening the time, it is preferable to collectively photograph a plurality of ink droplets K by one photographing using a high-angle, high-resolution camera, and most preferably, it is possible to photograph all of the ink droplets K discharged onto the substrate B1 at one time.

(deriving step)

The deriving step is a step of deriving the ejection amount of each nozzle of the ink ejected from the nozzle of the ink jet head 23 based on the information obtained in the obtaining step of S604. In S605, the control device 50 calculates the discharge amount of ink from each nozzle based on the image captured in S604. Specifically, the control device 50 determines the range of the ink droplet K ejected from each nozzle from the image, and derives the diameter of the ink droplet K. Further, the control device 50 derives the ink discharge amount from the derived diameter of the ink droplet K.

In the present embodiment, the discharge amount of ink is derived based on the diameter of the ink droplet K. Since the liquid-repellent coating material is applied to the base material B1, the ink does not penetrate into the base material B1. On the other hand, in the drying step of S603, the ink is dried, and the volume thereof is changed by a certain amount. As shown in fig. 4, the ink of the present embodiment is stable in volume after being dried to a certain extent. Therefore, the discharge amount of the ink discharged from the nozzle can be derived based on the ratio of the volume of the ink after stabilization to the volume of the ink corresponding to the composition of the ink. The time required for stabilizing the volume of the ink by drying varies depending on the composition of the ink and the surrounding environment, and is not limited to the above. In the present embodiment, the ambient environment (temperature, humidity) is preferably constant when the organic EL display panel is manufactured.

In the present embodiment, first, a table (not shown) for deriving the volume of the ink droplet K from the diameter of the ink droplet K on the substrate B1 is used. The diameter of the ink droplets K on the substrate B1 coated with the liquid-repellent coating material varies according to the surface tension and contact angle defined by the composition of the ink or the like, in addition to the amount of the ink. Therefore, a table defining the relationship between the diameter and the volume on the substrate B1 is used in correspondence with the ink used. The method of deriving the volume of the ink droplet K from the diameter of the ink droplet K is not limited to this. For example, a mathematical expression corresponding to the composition of the ink may be predetermined, and the volume may be calculated from the diameter of the ink droplet K using the mathematical expression.

The control device 50 derives the ink discharge amount from all the nozzles included in the ink jet head 23. In this step, the control device 50 may be configured to perform image processing on an image captured by the camera 31. For example, in order to detect the diameter of the ink droplet K more accurately, the configuration may be such that edge processing, filtering processing, or the like is performed. The ink ejection amount was measured by the steps S602 to S605 up to now.

[ adjustment method ]

The measurement adjustment method of the present embodiment preferably includes an adjustment method including the adjustment step described below after the measurement method including the measurement step is performed. In the present embodiment, the measurement method having the measurement step measures the amount of ink discharged by the inkjet device 1, and as a result, when the amount of ink discharged is deviated from the appropriate value, an adjustment step of adjusting the amount of ink discharged to the appropriate value is required. The measurement method having the above measurement step measures the amount of ink discharged by the inkjet device 1, and as a result, the adjustment step is not required as long as the amount of ink discharged is an appropriate value.

(adjustment procedure)

The adjustment step is a step of adjusting the discharge amount of the ink from the ink jet head 23, which is derived in the measurement step (S602 to S605), to an appropriate amount. In S606, the control device 50 adjusts the discharge amount of the ink from the corresponding nozzle to an appropriate amount based on the discharge amount of the ink derived in S605. The adjustment here may include detection of nozzles that do not eject ink, in addition to increase or decrease in the ejection amount of ink.

(discharge step)

In S607, the control device 50 discharges the base material B1. The discharge position of the substrate B1 may be the same as the insertion position of the substrate B1, or may be the downstream side in the transport direction of the substrate B1. The substrate B1 from the stage 40 may be discharged by a separate discharging device (not shown). In general, the present discharge step is performed after the measurement step or the final step of the adjustment step, that is, the measurement step and the adjustment step are completed normally. Then, the flow of the main ejection volume measurement adjustment process is ended.

The above example shows a configuration in which the discharge amount of ink is measured by 1 discharge in each nozzle of the ink jet head 23 and the discharge amount is adjusted. The measurement adjustment method of the present embodiment is not limited to this configuration, and may be configured to increase the adjustment accuracy by repeating the steps of S602 to S606 a plurality of times. Further, the adjustment may be configured such that information about the nozzle is notified when the nozzle that does not eject ink is generated.

When the steps S602 to S606 are repeated a plurality of times, the process is preferably completed in a short time, and the number of times the steps S602 to S606 are repeated is preferably small. The number of repetitions is usually 10 or less, preferably 5 or less, more preferably 3 or less, particularly preferably 2 or less, and most preferably 1 from the viewpoint of a short time. From the viewpoint of performing the steps S602 to S606 1 time to adjust the discharge amount of the ink from the ink jet head 23 and then confirming it, it is preferable to perform the steps 1 time more, that is, 2 times more. In the case of performing the measurement 2 times or more, the next step S606 may not be performed as long as the derived discharge amount of the ink is an appropriate value in the measurement steps 2 nd and subsequent times.

In the case where the same type of panel is manufactured using the same type of ink for a long period of time in panel manufacturing, since the data of the measurement process and the adjustment process are accumulated, the series of measurement processes and adjustment processes of S602 to S606 may be performed only 1 time, and from the standpoint of confirming the amount of ink discharged from the ink jet head 23 after the adjustment process, it is preferable to further perform the measurement process 1 time after the series of measurement processes and adjustment processes of S602 to S606. The adjustment step is not necessary as long as the amount of ink discharged from the ink jet head 23 derived in the measurement step is an appropriate amount. In this case, the process may be continued to the next discharge step of the substrate B1, or the measurement step may be performed again, and the discharge amount of the ink from the ink jet head 23 may be confirmed again to be an appropriate amount.

If the amount of ink discharged from the ink jet head 23 derived from the measurement step is an appropriate amount, it is preferable to transfer to the discharge step of the next substrate B1 without performing the measurement step again, from the viewpoint of shortening the time of the entire discharge amount measurement adjustment step (S607). On the other hand, from the viewpoint that it can be confirmed that there is no fluctuation or error in the discharge amount due to unexpected disturbance factors, and that the production with higher yield is possible, it is preferable that the measurement step is performed again when the discharge amount of the ink from the ink jet head 23 derived from the measurement step is an appropriate amount, and it is also confirmed that the discharge amount of the ink from the ink jet head 23 is an appropriate amount again.

In the measurement step, since a certain time is required to pass through the drying step (S603), it is not preferable in terms of manufacturing that a long time passes when the measurement step is repeated a plurality of times. Therefore, in the measurement step, it is preferable to perform the measurement step by ejecting a plurality of ink droplets from one nozzle to different positions on the substrate B1. With this method, even if the ejection is performed a plurality of times, it is preferable to reduce the influence of variations and errors in the ejection amount due to unexpected disturbance factors in the 1-time measurement step. In addition, it is also preferable that a plurality of ink droplets are ejected from one nozzle to different positions on the substrate B1 when a measurement step for reconfirming is performed after the adjustment step (S606) performed subsequently.

As described above, the ink of the present embodiment contains a high boiling point solvent. Since the high boiling point solvent does not evaporate at room temperature (i.e., in the manufacturing environment of the display panel D), the change in the diameter of the ink droplet K after the solvent is only the high boiling point solvent substantially disappears. Therefore, the diameter of the ink droplet K of the high boiling point solvent can be accurately measured from the captured image. If the content of the high boiling point solvent in the ink is accurately measured in advance, the diameter of the ink droplet K can be accurately converted into the ink ejection droplet amount. As a result, the amount of discharge of each nozzle of the ink jet head 23 can be appropriately measured. Further, the ejection amount of the nozzles in the ink ejection head 23 can be appropriately adjusted, and natural drying can be suppressed even when the ink is ejected onto the substrate B2 in the production of the display panel D due to the influence of the high boiling point solvent. As a result, the drawing process can be appropriately performed on the base material B2 without causing uneven film thickness in manufacturing the display panel D.

[ relation between the ejection amount measurement adjustment step and the panel manufacturing step ]

The panel manufacturing system of the organic EL display panel of the present embodiment has the above-described ejection amount measurement adjusting device, and has the organic EL display panel manufacturing device using the ink jet head 23 of the above-described ejection amount measurement adjusting device. After the completion of the discharge amount measurement adjustment step shown in fig. 6, the organic EL display panel was manufactured. In this case, the substrate B2 is inserted into the stage 40 instead of the substrate B1, and a panel is manufactured. Since the amount of ink to be discharged also varies depending on the batch of the ink jet head 23, it is necessary to use the ink jet head 23 having completed the discharge amount adjustment step shown in fig. 6 in the manufacture of the organic EL display panel. The timing of executing the adjustment operation shown in fig. 6 may be arbitrary. For example, the process may be performed before the production of the 1 st substrate B2 in the batch unit at the time of producing the organic EL display panel. Alternatively, the process may be performed for each substrate B2 used in manufacturing the organic EL display panel. When a plurality of ink ejection heads 23 are provided in correspondence with each of the plurality of layers constituting the organic EL display panel, the ink ejection heads 23 corresponding to the respective layers may be subjected to the ejection amount measurement adjustment step of fig. 6 independently, or the ink ejection heads 23 corresponding to the respective layers may be subjected to the ejection amount measurement adjustment step of fig. 6 in a lump.

In addition, after the ink jet head 23 is replaced or cleaned, the ejection amount measurement adjustment step of fig. 6 is also required. The reason for this is: in the case of changing the ink jet head 23, initial adjustment is required for all the nozzles of the ink jet head 23. When the cleaning is performed, there is a possibility that the ink discharge amount change is affected by unexpected, minute deformation of a portion below the detection limit and/or undetectable, minute displacement of the member, or the like. Further, even when the same type of ink is used, the ejection amount measurement adjustment step of fig. 6 is required in the case of changing the ink by a certain method. The reason for this is: even in the same type of ink, for example, in the case of different batches, minute fluctuations in the liquid properties of the ink may affect the variation in the discharge amount from the ink ejection head 23.

As described above, since the amount of ink to be discharged may vary depending on the batch of ink and the replacement of ink, it is preferable to directly use the ink having completed the discharge amount adjustment step shown in fig. 6 in the manufacture of the organic EL display panel. The ink having completed the ejection amount measurement adjustment step shown in fig. 6 was used as it is, and the state was as follows. That is, the ink ejected from the plurality of nozzles provided in the ink jet head 23 is normally continuously supplied to the ink jet head 23 from an ink storage portion (not shown) attached to the ink jet head 23 or an ink storage portion (not shown) connected to the ink jet head 23 by a pipe. The ink having completed the ejection amount measurement adjustment step shown in fig. 6 is used directly in the panel manufacturing step without re-supplying or replacing the ink in the ink storage portion after the completion of the ejection amount measurement adjustment step shown in fig. 6. In this way, after the completion of the ejection amount measurement adjustment step shown in fig. 6, the process can be shifted to the panel manufacturing step without any small variation in the physical properties of the ink, and therefore, panel manufacturing can be stably performed by the ink jet head 23 adjusted to an appropriate ejection amount, which is preferable.

Here, the "ejection amount measurement adjustment step" is described as "the ejection amount adjustment step shown in fig. 6", but this is merely a name of the step, and the content of the step is not represented by a statement thereof. That is, when the above-described measurement steps (S602 to S605) can confirm that the discharge amount is appropriate, the above-described adjustment step (S606) is not performed, and the "discharge amount adjustment step shown in fig. 6" is also included.

[ Structure of display Panel D ]

Next, a display panel D manufactured by the above-described method for measuring the amount of ink discharged or the method for adjusting the amount of ink discharged will be described with reference to fig. 10 to 12. Fig. 10 is a schematic plan view showing an exemplary configuration of the display panel D according to the present embodiment. Fig. 10 is a schematic diagram, and the scale may be different from the actual scale.

The display panel D of the present embodiment is an organic EL display panel utilizing the electroluminescence phenomenon of an organic compound. The display panel D has a top emission type structure in which a plurality of organic EL display elements each constituting a pixel are arranged in a matrix on a substrate (hereinafter, referred to as a "TFT substrate") on which thin film transistors (TFTs: thin Film Transistor) are formed, and light is emitted from the upper surface (color filter substrate 131 side). Here, the X direction, Y direction, and Z direction in fig. 10 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. 10, the display panel D of the present embodiment is composed of a divided region 10a and a non-divided region 10b located around the divided region 10 a. The dividing region 10a is divided into a matrix on the substrate 100 by banks (banks) 122 which limit light emitting units of respective colors (here, three colors of RGB). Note that, the banks 122 along the Y-axis direction are referred to as column banks 122Y, and the banks along the X-axis direction are referred to as row banks 122X.

A sealing member 300 is formed on a rectangle surrounding the divided region 10a in the non-divided region 10 b. The divided region 10a is constituted by a display pixel arrangement region 10e including the center of the substrate 100 and a non-light-emitting region 10ne located around the display pixel arrangement region 10 e. The display pixel arrangement region 10e is a region in which organic EL display elements are formed in each of the partitions defined by the column banks 122Y and the row banks 122X. On the other hand, the non-light-emitting region 10ne is a region where the organic EL display element is not formed.

Fig. 11 is a plan view of a part of the display pixel arrangement region 10e shown in fig. 10, which is enlarged in region 10 c. In the display pixel arrangement region 10e, unit elements 100e corresponding to the organic EL display elements are arranged on the row and column. The unit element 100e is a region where light is emitted from an organic compound. In this example, the unit element 100e includes 3 kinds of self-light emitting regions 100a corresponding to 3 colors, that is, a self-light emitting region 100aR emitting red (R) light, a self-light emitting region 100aG emitting green light, and a self-light emitting region 100aB emitting blue light.

As shown in fig. 11, a plurality of pixel electrodes 119 are arranged on the substrate 100 so as to be spaced apart from each other by a predetermined distance in the row direction and the column direction. The pixel electrodes 119 arranged in a matrix correspond to the self-luminous regions 100aR, 100aG, 100aB arranged in order in the row direction. The area other than the self-light emitting area 100a is a non-self-light emitting area 100b. A contact hole 119c connecting the pixel electrode 119 and the source of the TFT is provided in the non-self-light emitting region 100b. Further, a contact region 119b for electrically connecting to the pixel electrode 119 is provided in the non-self-light emitting region 100b.

Fig. 12 is a schematic cross-sectional view of the position of the cut at X1-X1 shown in fig. 11. As shown in fig. 12, the display panel D of the present embodiment is constituted by a substrate 100 (TFT substrate) on which a thin film transistor is formed below in the Z-axis direction, and an organic EL element portion as a light emitting element portion is formed thereon. The organic EL element section is composed of a plurality of layers, and the inkjet device 1 described above can be applied when forming a part thereof. The plurality of layers constituting the organic EL element include 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, a bonding layer 127, and a color filter substrate 131. The color filter substrate 131 includes a color filter layer 128 and an upper substrate 130. The following describes the portions constituting the display panel D.

(substrate (TFT substrate))

The substrate 100 is a support member for the display panel D, and includes: a substrate (not shown), a Thin Film Transistor (TFT) layer (not shown) formed on the substrate, and an interlayer insulating layer (not shown) formed on the substrate and the TFT layer.

The base material (not shown) constituting the substrate 100 is a support member for the display panel D, and has a flat plate shape. As a material of the base material, a material having electrical insulation, 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. For example, a glass substrate, a quartz substrate, a silicon substrate, molybdenum sulfide, copper, zinc, aluminum, stainless steel, a metal substrate such as magnesium, iron, nickel, gold, silver, a semiconductor substrate such as gallium arsenide substrate, a plastic substrate, or the like can be used as a base material.

The TFT layer (not shown) constituting the substrate 100 is composed of a plurality of TFTs and wirings formed on the upper surface of a base material. The TFT is configured by a multilayer structure such as an electrode, a semiconductor layer, and an insulating layer, and electrically connects the pixel electrode 119 corresponding to the TFT to an external power source (not shown) in response to a drive signal from an external circuit of the display panel D. Wiring (not shown) electrically connects the TFT, the pixel electrode 119, an external power source, an external circuit, and the like. The interlayer insulating layer located on the upper surface of the substrate 100 planarizes at least a portion of the upper surface of the substrate 100 having the irregularities through the TFT layer. In addition, an interlayer insulating layer fills between the wiring and the TFT, and electrically insulates between the wiring and the TFT.

As the interlayer insulating layer, for example, silicon oxide (SiO 2), silicon nitride (SiN), silicon oxynitride (SiON), silicon oxide (SiO), and silicon oxynitride (SiON) can be used. As the connection electrode layer of the TFT, for example, a laminate of molybdenum (Mo) and copper (Cu) and copper manganese (CuMn) can be used. The interlayer insulating layer is formed using an organic compound such as a polyimide resin, an acrylic resin, a siloxane resin, or a novolac type phenol resin, and the thickness of the interlayer insulating layer may be in the range of 2000nm to 8000nm, for example.

(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 configured to supply carriers to the light-emitting layer 123, and for example, to supply holes to the light-emitting layer 123 when functioning as an anode. The pixel electrode 119 is a flat plate formed in a rectangular shape. In addition, a connection recess of the pixel electrode 119, a part of which is recessed in the substrate 100 direction, is connected to the source of the TFT through a contact hole formed in the upper surface of the substrate 100.

The pixel electrode 119 is composed of a metal material. In the case of the top emission type organic EL display panel, the chromaticity of the emitted light is adjusted and the luminance is improved by setting the layer thickness to be optimal 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 stacked. As the metal layer, for example, it may be composed of a metal material containing silver (Ag) or aluminum (Al). As the alloy layer, for example, APC (alloy of silver, palladium, copper), ARA (alloy of silver, rubidium, gold), moCr (alloy of molybdenum and chromium), niCr (alloy of nickel and chromium), or the like can be used. As a constituent material of the transparent conductive layer, for example, indium Tin Oxide (ITO), indium Zinc Oxide (IZO), or the like can be used.

(hole injection layer, hole transport layer)

A hole injection layer 120 and a hole transport layer 121 are sequentially stacked 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 holes injected from the pixel electrode 119 to the light emitting layer 123.

The hole injection layer 120 is, for example, a layer made of an oxide such as silver (Ag), molybdenum (Mo), chromium (Cr), vanadium (V), tungsten (W), nickel (Ni), iridium (Ir), or a conductive polymer material.

Examples of the conductive polymer material that can be used for the hole injection layer 120 or the hole transport layer 121 include polyvinylcarbazole or a derivative thereof, polysilane or a derivative thereof, a polysiloxane derivative having an aromatic amine in a side chain or a main chain, a pyrazoline derivative, an arylamine derivative, a stilbene derivative, a triphenyldiamine derivative, polyaniline or a derivative thereof, polythiophene or a derivative thereof, polypyrrole or a derivative thereof, poly (p-phenylene vinylene) or a derivative thereof, and poly (2, 5-thienylene vinylene) or a derivative thereof. Specifically, examples of the hole transporting material include compounds described in JP-A-63-70257, JP-A-63-175860, JP-A-2-135359, JP-A-2-135361, JP-A-2-209988, JP-A-3-37992, and JP-A-3-152184.

Among these, as the hole transport material used in the hole transport layer 121, a hole transport material such as polyvinylcarbazole or a derivative thereof, polysilane or a derivative thereof, a polysiloxane derivative having an aromatic amine compound group in a side chain or a main chain, polyaniline or a derivative thereof, polythiophene or a derivative thereof, poly (p-phenylene vinylene) or a derivative thereof, or poly (2, 5-thienylene vinylene) or a derivative thereof is preferable, and polyvinylcarbazole or a derivative thereof, polysilane or a derivative thereof, a polysiloxane derivative having an aromatic amine in a side chain or a main chain is more preferable. In the case of a low-molecular hole transport material, it is preferable to use a polymer binder dispersed therein.

The polyvinylcarbazole or derivative thereof is obtained, for example, from vinyl monomers by cationic polymerization or radical polymerization. The polysiloxane or a derivative thereof preferably uses a compound having the structure of the hole transporting material described above in a side chain or a main chain in the siloxane skeleton structure. In particular, an aromatic amine compound having hole-transporting property in a side chain or a main chain can be exemplified.

The hole injection layer 120 and the hole transport layer 121 may be formed using the inkjet device 1 shown in fig. 1. The ink used to form the hole injection layer 120 and the hole transport layer 121 is not particularly limited as long as the hole injection material and the hole transport material are dissolved in the organic solvent.

(dyke)

A bank 122 made of an insulator is formed so as to cover the end edges of the pixel electrode 119, the hole injection layer 120, and the hole transport layer 121. In order to prevent leakage of current in the thickness direction (Z-axis direction) between the outer edge of the pixel electrode 119 and the counter electrode 125 in the bank 122, the bank 122 preferably has a volume resistivity of 1×10 ⁶ Insulation of Ω cm or more.

The bank 122 is formed of an organic material such as resin, and has insulation properties. Examples of the organic material for forming the banks 122 include acrylic resins, polyimide resins, and novolac-type phenolic resins. The banks 122 preferably have resistance to organic solvents. More preferably, an acrylic resin is used. This is because the refractive index of the acrylic resin is low and is suitable as a reflector.

When an inorganic material is used for the bank 122, silicon oxide (SiO) is preferably used from the viewpoint of refractive index, for example. Alternatively, the bank 122 is formed using an inorganic material such as silicon nitride (SiN) or silicon oxynitride (SiON).

Further, the bank 122 may be formed of a material having high resistance, such as a material that does not excessively deform or deteriorate, because an etching process, a baking process, or the like is sometimes performed in the panel manufacturing process. In order to impart liquid repellency to the surface, the surface of the bank 122 may be subjected to fluorine treatment by CVD (chemical vapor deposition method, chemical Vapor Deposition) or the like.

(light-emitting layer)

A light emitting layer 123 that emits light of various colors is formed on the display panel D. Specific examples of the colors include 3 colors of 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 internally recombining holes and electrons. The light-emitting layer 123 emits light only from the portion to which carriers are supplied from the pixel electrode 119. The light emitting layer 123 may be formed using the inkjet device 1 shown in fig. 1.

The material for forming the light-emitting layer 123 needs to be a light-emitting organic material that can be formed into a film by a wet printing method. The light-emitting layer 123 is not particularly limited as long as it is a layer made of a known material that can be used for a light-emitting layer (layer having a light-emitting function) of the organic EL element portion, and is preferably a light-emitting layer made of an organic material. For example, a layer formed of an organic substance (a low-molecular compound and a high-molecular compound) that emits fluorescence or phosphorescence as a light-emitting material and a dopant that assists the light-emitting material is preferable.

Examples of such luminescent materials (organic substances that emit fluorescence or phosphorescence) include a pigment-based material, a metal complex-based material, and a polymer-based material. Examples of such pigment-based materials include cyclopentylamine derivatives, tetraphenylbutadiene derivative compounds, triphenylamine derivatives, Diazole derivatives, pyrazoloquinoline derivatives, distyrylbenzene derivatives, distyrylarylene derivatives, pyrrole derivatives, thiophene ring compounds, pyridine ring compounds, pyrenone derivatives, perylene derivatives, oligothiophene derivatives, and their derivatives>Diazole dimers, pyrazoline dimers, and the like.

Examples of the metal complex-based material include aluminum hydroxyquinoline complex, benzoquinoline beryllium complex, and benzo-quinoline beryllium complexThe zinc azole complex, zinc benzothiazole complex, zinc azo methyl complex, zinc porphyrin complex, europium complex and other central metals have aluminum (Al), zinc (Zn) and beryllium(Be) or the like or terbium (Tb), europium (Eu), dysprosium (Dy) or the like and having a ligand of +.>Metal complexes of diazoles, thiadiazoles, phenylpyridine, phenylbenzimidazole, quinoline structures, and the like.

Further, examples of the polymer material include a polyparaphenylene vinylene derivative, a polythiophene derivative, a polyparaphenylene derivative, a polysilane derivative, a polyacetylene derivative, a polyfluorene derivative, a polyvinylcarbazole derivative, and a substance obtained by polymerizing the dye body and the metal complex-based light emitting material.

Among such luminescent materials, examples of the blue light-emitting material include distyrylarylene derivatives,Diazole derivatives and their polymers, polyvinylcarbazole derivatives, polyparaphenylene derivatives, polyfluorene derivatives, etc. Among them, polyvinylcarbazole derivatives, polyparaphenylene derivatives, polyfluorene derivatives, and the like of the polymer materials are preferable.

Examples of the light-emitting material emitting green light include quinacridone derivatives, coumarin derivatives, polymers thereof, parylene derivatives, and polyfluorene derivatives. Among them, preferred are poly-p-phenylene vinylene derivatives and polyfluorene derivatives of polymer materials.

Examples of the luminescent material that emits red light include coumarin derivatives, thiophene ring compounds, polymers thereof, poly-p-phenylene vinylene derivatives, polythiophene derivatives, and polyfluorene derivatives. Among them, preferred are poly-p-phenylene vinylene derivatives, polythiophene derivatives, polyfluorene derivatives, and the like of the polymer material.

The method for producing such a luminescent material is not particularly limited, and a known method can be suitably used, and for example, the method described in japanese patent application laid-open No. 2012-144722 can be used.

In addition, for the purpose of improving the light emission efficiency, changing the light emission wavelength, and the like, the ink used in forming the light-emitting layer 123 is preferably doped with a dopant. Examples of such dopants include perylene derivatives, coumarin derivatives, rubrene derivatives, quinacridone derivatives, squarylium derivatives, porphyrin derivatives, styryl pigments, naphthacene derivatives, pyrazolone derivatives, decacyclic olefins, and phenonesOxazinones, and the like. It is preferable that the thickness of such a light-emitting layer 123 is generally about

By using an ink containing an organic solvent having a high boiling point of 250 ℃ or higher, preferably 300 ℃ or higher, the film shape of the light-emitting layer 123 to be formed is also formed to have a shape equivalent to the film thickness at the peripheral portion and the central portion of the film formation region. That is, with the ink of the present embodiment, it is possible to suppress the film thickness variation caused by the imbalance in the solvent evaporation rate accompanying the vapor concentration distribution of the ink solvent in the central portion and the peripheral portion of the substrate.

(Electron transport layer)

An electron transport layer 124 is formed on the bank 122 and within the opening defined by the bank 122, on the light emitting layer 123. The electron transport layer 124 has a function of transporting electrons injected from the counter electrode 125 to the light emitting layer 123. The electron transport layer 124 uses, for example Oxadiazole derivatives (OXD), triazole derivatives (TAZ), phenanthroline derivatives (BCP, bphen), and the like.

(counter electrode)

The counter electrode 125 is formed by laminating the electron transport layers 124. The counter electrode 125 may be formed in a continuous state on the entire display panel D, and connected to a bus bar wiring (not shown) by a pixel unit or several pixel units. The counter electrode 125 forms an energizing path by sandwiching the light emitting layer 123 with the pixel electrode 119, and supplies carriers to the light emitting layer 123. When the counter electrode 125 functions as a cathode, for example, electrons are supplied to the light-emitting layer 123. The counter electrode 125 is formed along the surface of the electron transport layer 124 and serves as an electrode shared with the light emitting layers 123 formed between the banks 122. The counter electrode 125 is made of a light-transmitting conductive material. For example, the counter electrode 125 is formed using Indium Tin Oxide (ITO), indium Zinc Oxide (IZO), or the like. An electrode formed by thinning silver (Ag) or aluminum (Al) may be used as the counter electrode 125.

(sealing layer)

The sealing layer 126 is formed by laminating the opposite electrodes 125. In order to suppress deterioration of the light-emitting layer 123 due to contact with moisture, air, or the like, the sealing layer 126 is formed. 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. The sealing layer 126 is formed using a light-transmitting material such as silicon nitride (SiN) or silicon oxynitride (SiON). Further, a sealing resin layer made of a resin material such as an acrylic resin or a silicone resin may be provided on a layer formed of a material such as silicon nitride (SiN) or silicon oxynitride (SiON).

(bonding 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 the following functions: the back panel formed of the layers from the substrate 100 to the sealing layer 126 is bonded to the color filter substrate 131, and the layers are prevented from being exposed to moisture and air. As a material of the bonding layer 127, for example, a light-transmitting material resin material such as an acrylic resin, a silicone resin, or an epoxy resin can be used.

(upper substrate)

In the upper substrate 130 constituting the color filter substrate 131, since the display panel D is of a top emission type, a light-transmitting material such as cover glass or a transparent resin film can be used, for example. In addition, the display panel D can achieve an improvement in rigidity, prevention of intrusion of moisture, air, and the like, through the upper substrate 130. As the light-transmitting material, for example, a glass substrate, a quartz substrate, a plastic substrate, or the like can be used.

(color Filter layer)

On the color filter substrate 131, color filter layers 128 corresponding to respective colors are formed at positions corresponding to light emitting regions of pixels. 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 to transmit visible light having a wavelength corresponding to each color (for example, R, G, B), and has a function of transmitting light emitted from each color pixel and correcting chromaticity thereof. Specifically, the color filter layer 128 is formed by applying ink containing a color filter material and a solvent to an upper substrate 130 made of cover glass for forming a color filter in which a plurality of openings are formed in a matrix in a pixel unit.

[ Panel manufacturing Process of display Panel D ]

Next, a panel manufacturing process of the display panel D will be described with specific examples. The light-emitting layer 123, the hole injection layer 120, and the hole transport layer 121 in the structure of the display panel D shown in fig. 10 to 12 can be formed using an inkjet method. Therefore, in this embodiment, a method for measuring the amount of ink discharged or a method for adjusting the amount of ink discharged, which will be described with reference to fig. 6, will be described as a method used when forming these 3 layers. Therefore, the panel manufacturing system of the display panel D of the present embodiment is preferably a panel manufacturing system having the above-described ink discharge amount measurement and adjustment device in addition to the display panel manufacturing device itself for manufacturing the display panel D. Fig. 13 is a flowchart showing a panel manufacturing process of the display panel D.

In the present embodiment, the ink jet head 23 corresponding to each layer is provided. In short, the constitution shown in fig. 1 is prepared for forming the light-emitting layer 123, the hole injection layer 120, and the hole transport layer 121, respectively. In order to simplify the explanation, the process for manufacturing the display panel D will be described as a process for controlling the entire control device 50. At the beginning of the main panel manufacturing process flow, a substrate 100 composed of a base material, a TFT layer, and an interlayer insulating layer is prepared.

(S1301)

In S1301, the control apparatus 50 forms the pixel electrode 119 on the substrate 100. Specifically, a contact hole (not shown) is formed in the interlayer insulating layer of the substrate 100, and a pixel electrode 119 is formed. The pixel electrode 119 is formed by forming a metal film by a sputtering method, a vacuum evaporation method, or the like, and then patterning the metal film by a photolithography method or an etching method. The pixel electrode 119 is electrically connected to an electrode of a TFT constituting the substrate 100.

(S1302)

In S1302, the control device 50 forms the bank 122. In the formation of the banks 122, the banks 122 along a predetermined direction are formed, and then the banks in a direction orthogonal to the predetermined direction are formed. Formation of the banks 122 a film made of a constituent material (for example, a photosensitive resin material) of the banks 122 is laminated. Then, the resin film is patterned to sequentially form banks. The patterning of the banks may be performed by exposing the resin film to light using a photomask and performing a development step and a calcination step (for example, at about 230 ℃ for about 60 minutes).

In the step of forming the bank 122, first, a photosensitive resin film made of an organic photosensitive resin material, for example, an acrylic resin, a polyimide resin, a novolac type phenol resin, or the like is formed using a spin coating method or the like. Then, the solvent is evaporated to a certain extent by drying, and then a photomask having a predetermined opening is superimposed. Further, ultraviolet irradiation is performed from above, a photoresist made of a photosensitive resin or the like is exposed, and a pattern of a photomask is transferred to the photoresist. Next, an insulating layer is formed by patterning the banks 122 by developing the photosensitive resin. A photoresist called positive type is generally used. The positive type is developed to remove the exposed portion. The portion of the mask pattern that is not exposed is not developed and the bank 122 remains with a certain thickness.

(S1303)

In S1303, control device 50 stacks hole injection layer 120 on pixel electrode 119. The hole injection layer 120 may be formed by an ink-jet method using an ink in which a conductive polymer material is dissolved in an organic solvent. In the present embodiment, when forming the hole injection layer 120, first, the ejection amount of each nozzle of the ink jet head 23 is adjusted by the method shown in fig. 6 using the above-described ink ejection amount measurement adjustment device. At this time, the substrate B1 inserted in the insertion step (S601) of fig. 6 is a substrate coated with a liquid repellent coating material having liquid repellency to the ink used when the hole injection layer 120 is formed. After the adjustment of the ejection amount is completed, the ink containing the conductive polymer material is formed into the hole injection layer 120 at a predetermined position defined by the bank 122 by using an inkjet method.

(S1304)

In S1304, the control device 50 stacks the hole transport layer 121 on the hole injection layer 120. The hole transport layer 121 may be formed using an ink in which a conductive polymer material is dissolved in an organic solvent, and by an inkjet method. In the present embodiment, when forming the hole transport layer 121, first, the ejection amount of each nozzle of the ink jet head 23 is adjusted by the method shown in fig. 6 using the above-described ink ejection amount measurement adjustment device. At this time, the substrate B1 inserted in S601 of fig. 6 is a substrate coated with a liquid repellent coating material having liquid repellency to the ink used when forming the hole transport layer 121. After the adjustment of the discharge amount is completed, the ink containing the conductive polymer material is formed into the hole transport layer 121 at a predetermined position defined by the bank 122 by using an inkjet method.

(S1305)

In S1305, the control device 50 stacks the light-emitting layer 123 on the hole transport layer 121 at a predetermined position defined by the bank 122. In the present embodiment, when forming the light-emitting layer 123, first, the discharge amount of each nozzle of the ink jet head 23 is adjusted by the method shown in fig. 6 using the above-described ink discharge amount measuring device. At this time, the substrate B1 inserted in the insertion step (S601) of fig. 6 is a substrate coated with a liquid repellent coating material having liquid repellency to the ink used in forming the light emitting layer 123. After the adjustment of the discharge amount is completed, the light-emitting layer 123 is formed by an inkjet method. As described above, the light emitting layer 123 is formed corresponding to each of the plurality of colors (for example, 3 colors of R, G, B) reproduced in the organic EL light emitting panel. The arrangement of the light-emitting layers 123 corresponding to the respective colors on the substrate 100 is predetermined, and the arrangement is performed. The order and arrangement of formation of the light-emitting layers 123 corresponding to the respective colors are not particularly limited, and any setting may be used.

(S1306)

In S1306, the control device 50 stacks the electron transport layer 124 on the light emitting layer 123. The electron transport layer 124 may be formed using a vacuum evaporation method or the like. In the case of forming the electron transport layer 124 by wet deposition, the process of adjusting the ejection amount of each nozzle of the ink jet head 23 (S606) is preferably performed by the method shown in fig. 6 by using the above-mentioned ink ejection amount measurement adjustment device, as in the processes of S1303 to S1305.

(S1307)

In S1307, the control apparatus 50 stacks the counter electrode 125 so as to cover the electron transport layer 124 as a solid film (solid film). The counter electrode 125 can be formed by CVD, sputtering, or the like.

(S1308)

In S1308, the control device 50 stacks the sealing layer 126 so as to cover the counter electrode 125 as a solid film. The sealing layer 126 can be formed by a CVD method, a sputtering method, or the like similarly to the counter electrode 125.

(S1309)

In S1309, the control apparatus 50 forms a color filter substrate 131. In forming the color filter substrate 131, first, a transparent upper substrate 130 is prepared. Next, a paste in which a material of the color filter layer 128 (for example, G) containing an ultraviolet curable resin component as a main component is dispersed in a solvent is applied to the surface of the upper substrate 130, and after a certain solvent is removed, a predetermined pattern mask is placed thereon, and ultraviolet irradiation is performed. Then, the pattern mask and the uncured paste are removed by curing, and the color filter layer (G) is formed by developing. The color filter layers (R) and (B) are formed by repeating the process for the color filter material of each color. In addition, a commercially available color filter product may be used instead of using a paste. In addition, the color filter substrate 131 may be formed in advance, and only the formed color filter substrate 131 may be provided in this step.

(S1310)

In S1310, the control device 50 bonds the color filter substrate 131 to the rear panel. In this step, first, a material of the bonding layer 127 containing an ultraviolet curable resin such as an acrylic resin, a silicone resin, or an epoxy resin as a main component is applied to the back panel composed of the layers from the substrate 100 to the sealing layer 126. Then, the coated material is irradiated with ultraviolet rays, and the rear panel and the color filter substrate 131 are bonded to each other in a state where the relative positional relationship therebetween is matched. At this time, bonding is performed so as to avoid gas from entering between the two. Then, the two substrates are baked to complete the sealing process, thereby completing the display panel D. Then, the main panel manufacturing process is ended.

In the above example, the inkjet method was used to form 3 layers of the light-emitting layer 123, the hole injection layer 120, and the hole transport layer 121, and in this case, the measurement and adjustment of the amount of ink discharged in this embodiment were performed by the method shown in fig. 6 by using the above-described ink discharge amount measurement and adjustment device. However, the present invention is not limited to these layers, and may be applied to at least 1 layer among the layers constituting the display panel D. Therefore, when the inkjet system is used for forming other layers, the method for measuring and adjusting the amount of ink discharged in the present embodiment can be applied for forming these layers.

Verification example

The verification result using the method of the present embodiment will be described below. In this embodiment, the results of the comparison were shown by using 5 examples of 3 compositions 1 to 3 having the characteristics of the present embodiment and 2 comparative compositions 1 and 2 as comparative examples. Here, the ink used for forming the hole injection layer 120 will be described as an ink in which the same functional material is used for all the inks. Fig. 14A is a table diagram showing the composition of each composition.

(composition 1)

The ink composition 1 used a functional polymer compound having a repeating structure represented by the following chemical formula P1 as a functional material, namely, a charge transporting material, and 4-isopropyl-4' -methyldiphenyliodonium tetrakis (pentafluorophenyl) borate as an electron accepting compound in an amount of 5:1, and a composition obtained by mixing the components in a proportion. In addition, in the composition 1, as the organic solvent, butyl benzoate (boiling point 250 ℃) was used: toluene (boiling point 110 ℃) =2: 8, and mixing the organic solvents in proportion. Then, these functional materials (solutes) were dissolved in an organic solvent, and the organic solvent having a boiling point of 250 ℃ or higher (butyl benzoate in this case) was prepared so as to be 2.0 wt% with respect to the whole composition 1.

(composition 2)

The ink composition 2 used a functional polymer compound having a repeating structure of the above chemical formula P1 as a functional material, namely a charge transporting material, and 4-isopropyl-4' -methyldiphenyliodonium tetrakis (pentafluorophenyl) borate as an electron accepting compound in an amount of 5:1, and a composition obtained by mixing the components in a proportion. In addition, in the composition 2, as the organic solvent, 2-ethylhexyl benzoate (boiling point 297 ℃) was used: mesitylene (boiling point 164.7 ℃) =2: 8, and mixing the organic solvents in proportion. Then, these functional materials (solutes) were dissolved in an organic solvent, and the organic solvent having a boiling point of 250 ℃ or higher (here, 2-ethylhexyl benzoate) was prepared so as to be 2.0 wt% with respect to the entire composition 2.

(composition 3)

The ink composition 3 used a functional polymer compound having a repeating structure of the above chemical formula P1 as a functional material, namely a charge transporting material, and 4-isopropyl-4' -methyldiphenyliodonium tetrakis (pentafluorophenyl) borate as an electron accepting compound in an amount of 5:1, and a composition obtained by mixing the components in a proportion. In addition, in the composition 3, benzyl benzoate (boiling point 323 ℃) was used as the organic solvent: toluene (boiling point 110 ℃) =2: 8, and mixing the organic solvents in proportion. Then, these functional materials (solutes) were dissolved in an organic solvent, and the organic solvent having a boiling point of 250 ℃ or higher (benzyl benzoate in this case) was prepared so as to be 2.0 wt% with respect to the whole composition 3.

(composition 4)

The ink composition 4 used a functional polymer compound having a repeating structure of the above chemical formula P1 as a functional material, namely a charge transporting material, and 4-isopropyl-4' -methyldiphenyliodonium tetrakis (pentafluorophenyl) borate as an electron accepting compound in an amount of 5:1, and a composition obtained by mixing the components in a proportion. In addition, in the composition 4, benzyl benzoate (boiling point 323 ℃) was used as the organic solvent: cyclohexylbenzene (boiling point 238.9 ℃) =2: 8, and mixing the organic solvents in proportion. Then, these functional materials (solutes) were dissolved in an organic solvent, and the organic solvent having a boiling point of 250 ℃ or higher (benzyl benzoate in this case) was prepared so as to be 2.0 wt% with respect to the entire composition 4.

(comparative composition 1)

Comparative ink composition 1 using a functional polymer compound having a repeating structure of the above chemical formula P1 as a functional material, namely, a charge transporting material, and 4-isopropyl-4' -methyldiphenyliodonium tetrakis (pentafluorophenyl) borate as an electron accepting compound in an amount of 5:1, and a composition obtained by mixing the components in a proportion. In comparative composition 1, tetralin (boiling point 207.5 ℃) was used as the organic solvent: toluene (boiling point 110 ℃) =2: 8, and mixing the organic solvents in proportion. Then, these functional materials (solutes) were dissolved in an organic solvent, and the organic solvent on the high boiling point side (tetrahydronaphthalene in this case) was prepared so as to be 2.0 wt% with respect to the whole of the comparative composition 1.

(comparative composition 2)

Comparative ink composition 2 using a functional polymer compound having a repeating structure of the above chemical formula P1 as a functional material, namely, a charge transporting material, and 4-isopropyl-4' -methyldiphenyliodonium tetrakis (pentafluorophenyl) borate as an electron accepting compound was prepared in a ratio of 5:1, and a composition obtained by mixing the components in a proportion. In comparative composition 2, cyclohexylbenzene (boiling point: 238 ℃ C.) was used as the organic solvent: toluene (boiling point 110 ℃) =2: 8, and mixing the organic solvents in proportion. Then, these functional materials (solutes) were dissolved in an organic solvent, and the organic solvent on the high boiling point side (cyclohexylbenzene in this case) was prepared so as to be 2.0 wt% relative to the whole of comparative composition 2.

(evaluation 1)

First, as evaluation 1 in the present verification, changes in diameter and volume of ink droplets were observed. The substrate B1 used in the measurement was a substrate obtained by uniformly coating the entire surface of a glass substrate with a general polyimide-based photoresist as a liquid repellent coating material. A substrate was prepared in which the surface of the polyimide cured film of the base material was subjected to a surface treatment by a CVD method using CF4 gas so that the contact angle with anisole was 50 degrees.

In evaluation 1, the measurement was performed according to the following procedure. Ink droplets of each composition are ejected onto the substrate B1. Then, the ink droplets K were photographed at each time of natural drying (10 minutes) and natural drying (30 minutes). Then, the diameter of the ink droplet K is derived from the photographed image, and the residual volume of the ink droplet K is derived from the diameter. The values obtained as a result of this measurement are shown in fig. 14B.

Fig. 14B shows the volume of the remaining droplets of ink derived from the diameters of the ink droplets K derived from the images of the respective compositions and the change rates thereof. As is clear from the results shown in fig. 14B, the ink (composition 1 to composition 3) having an organic solvent having a boiling point of 250 ℃ or higher of 20% by weight or more relative to the whole ink had a small rate of change in volume after a predetermined time (10 minutes in this case) and had a stable liquid amount. On the other hand, with respect to the ink used as the comparative example (comparative composition 1), curing was generated due to natural drying for 10 minutes.

As is clear from the measurement results, by using the ink having the characteristics of the present embodiment and measuring the liquid amount after a predetermined time has elapsed, stable liquid amount measurement can be realized.

(evaluation 2)

Next, evaluation 2 in the present verification will be described. Upon receiving the results of evaluation 1, the ejection amount of the ink jet head 23 was adjusted, ink was applied to a predetermined application region, and the film thickness of the dried coating film of the functional layer was measured after drying under reduced pressure. The substrate B2 used here was prepared as follows: after patterning the glass substrate with the polyimide-based photoresist used in evaluation 1 so that the film thickness was 2 μm, the pixel width was 90 μm, and the bank width was 10 μm, the liquid repellency of the bank surface was adjusted by the CVD method so that the contact angle was 50 degrees at anisole.

Fig. 15 is a schematic view showing a position of film thickness measurement on the substrate B2 in the evaluation 2. In the test of evaluation 2, as shown by the arrow in fig. 15, the film thickness from the end to the end was measured 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. 11) of the substrate B2. The measurement length from end to end was 20cm. Further, the target value of the film thickness after drying of the functional layer was set to 60nm.

Fig. 16 shows the measurement result of evaluation 2 in the present verification. As shown in fig. 14B, in comparative composition 1, since the droplet diameter was not measured in evaluation 1, the ejection amount was not adjusted, and evaluation 2 was not performed. In fig. 16, the vertical axis represents the film thickness [ nm ] of the formed layer, and the horizontal axis represents the position [ cm ] of the formed layer. As described above, the measurement position of the film thickness was in the range of 20cm from end to end.

Referring to fig. 16, the compositions 1 to 3 having the characteristics of the ink according to the present embodiment are suitable for manufacturing the display panel D, because the film thickness variation of the functional layer to be formed is small. On the other hand, it was confirmed that the comparative composition 2 was unable to smoothly adjust the discharge amount, and the coating end portion was not uniform in film thickness due to the film thickness deviation and insufficient fluidity caused by drying.

(evaluation 3)

Next, the following evaluation was performed. As the base material B1 used in the measurement, a substrate in which a liquid repellent film is formed by applying a liquid repellent resist to a glass substrate was used. The contact angle of the ink of composition 4 on the substrate B1 was 61.5 degrees. The ink droplets of the composition 4 were discharged onto the substrate B1, and the ink droplets K were photographed at each time of 1 minute later, 5 minutes later, 10 minutes later, 20 minutes later, and 30 minutes later in a naturally dried state. The diameter of the ink droplet K is then derived from the captured image. Further, after the organic solvent was evaporated by heat drying, the image was taken in the same manner to obtain the diameter of the droplet K. The values obtained as a result of this measurement are shown in fig. 17.

In this evaluation, it was determined whether or not a certain proportion of the amount of ink was maintained with respect to the discharge amount of ink after the ink was discharged onto the substrate B1 and after a predetermined time had elapsed, based on the change in the diameter of the droplet K. Fig. 17 shows the change in diameter of the ink droplet K derived from the image of the composition 4. As is clear from the results shown in fig. 17, even when the organic solvent having a boiling point of not less than 250 ℃ was used as the organic solvent having a boiling point of not less than 250 ℃ and not more than 238.9 ℃ was used, the rate of change of the droplet diameter was small after 5 minutes, and the rate of change of the droplet diameter was small and stable until it was naturally dried for 30 minutes. After natural drying for 30 minutes, the organic solvent was removed by heat drying, and then the droplet K was reduced, so that it was found that the organic solvent having a boiling point of 250℃or higher was stably present when natural drying was performed for 30 minutes.

As described above, since the organic solvent having a boiling point of 250 ℃ or higher does not evaporate and dry in a normal temperature environment, there is little change in the amount of the organic solvent, and the droplet diameter can be measured without requiring a special device. In addition, the fluidity of the ink can be ensured in the organic EL display panel having the banks in a row by containing the organic solvent having the boiling point of 250 ℃ or higher, and the variation in film thickness can be suppressed.

By using the ink of the present application, the discharge amount of ink droplets can be derived in a short time without requiring a step of measuring the ink droplets that change with the passage of time. Then, the droplet discharge amount per ink jet nozzle can be easily made uniform based on the derived discharge amount. Therefore, a decrease in the production efficiency of the inkjet device due to the measurement of the amount of discharged liquid droplets can be suppressed. In addition, in the present embodiment, since large-scale equipment is not required for droplet observation, the device cost is reduced.

Further, by performing the ejection failure inspection using the measurement method of the present embodiment, it is possible to detect ejection failure of a nozzle such as drop off of a droplet or a flight curve.

In the present application, the ink required for measuring the liquid amount of the ink droplets discharged from the ink jet head is only required to be very small, and therefore, the ink can be efficiently used without wasting a functional material such as an expensive organic EL material. In addition, the ink of the present application can reduce uneven coating due to natural drying or the like when forming a pixel pattern on a substrate after adjustment of the ejection amount.

< other embodiments >

In the present application, a program for realizing the functions of the above 1 or more embodiments, an application program, a network, a storage medium, or the like may be provided to a system or an apparatus, and a processor of 1 or more of the computers of the system or the apparatus may read and execute the program.

Further, the present application may be realized by a circuit that realizes 1 or more functions (for example, ASIC (application specific integrated circuit, application Specific Integrated Circuit), FPGA (field programmable gate array )).

The present application is not limited to the above-described embodiments, and various configurations of the embodiments are combined with each other, and modifications and applications of the present application are intended by those skilled in the art based on descriptions of the specification and well-known techniques, and are included in the scope of the claims.

While various embodiments have been described above with reference to the drawings, the present application is not limited to this example. It is obvious to those skilled in the art that various modifications and corrections can be made within the scope described in the scope of the patent claims, and it is understood that they are of course also within the technical scope of the present application. The components in the above embodiments may be arbitrarily combined within a range not departing from the gist of the present application.

The present application is based on japanese patent application (japanese patent application 2020-202834) filed on 12/7/2020, the contents of which are incorporated herein by reference.

Industrial applicability

The method for measuring the discharge amount of ink, the apparatus for manufacturing an organic EL display panel, the ink, and the organic EL display panel manufactured using the ink according to the present application can be widely used for manufacturing display panels and the like in devices such as televisions, personal computers, and mobile phones, and various electronic devices having display panels. In addition, the present application can be widely used for manufacturing electronic devices including a step of forming a functional layer by using an ink application step.

Symbol description

1 … ink jet device

10 … X-axis workbench

11 … Y-axis workbench

12 … X-axis guide rail

13 … Y-axis guide rail

20 … bracket Unit

21 … bracket support

22 … bracket

23 … ink jet head

30 … camera unit

31 … camera

32 … camera support

40 … objective table

41 … objective table rotating mechanism

42 … X-axis sliding block

50 … control device

100 … substrate

119 … pixel electrode

120 … hole injection layer

121 … hole transport layer

122 … dyke

123 … luminous layer

124 … electron transport layer

125 … counter electrode

126 … seal layer

127 … joint layer

128 … color filter layer

130 … upper substrate

131 … color filter substrate

201 … nozzle hole

202 … ink drops

B … substrate

B1 … base material (for measuring discharge amount)

B2 … base material (for Forming Pattern)

K … ink drops

Claims

1. A measurement adjustment method is characterized by comprising at least a measurement method for measuring the discharge amount of ink from an ink jet head,

the measurement method comprises the following steps:

an ejection step of ejecting ink from the ink ejection head onto a substrate,

after a predetermined time has elapsed after the ink is discharged from the ink discharge head, the amount of ink discharged onto the substrate is maintained at a predetermined ratio to the amount of ink discharged from the ink discharge head.

2. The measurement adjustment method according to claim 1, further comprising a drying step of drying the ink discharged onto the substrate during the predetermined time period,

after the drying step, the obtaining step is performed.

3. The method for measuring and adjusting according to claim 1 or 2, wherein the ink contains a solvent and a functional material,

4. A measurement adjustment method is characterized by comprising at least a measurement method for measuring the discharge amount of ink from an ink jet head,

the measurement method comprises the following steps:

an ejection step of ejecting ink from the ink ejection head onto a substrate,

the ink comprises a solvent and a functional material,

5. The measurement adjustment method according to claim 4, further comprising a drying step of drying the ink discharged onto the substrate for a predetermined period of time,

After the drying step, the obtaining step is performed.

6. The measurement adjustment method according to any one of claims 1 to 3 and 5, wherein the predetermined time is 5 minutes or longer.

7. The method according to any one of claims 1 to 6, wherein the ink contains a solvent and a functional material,

8. The measurement adjustment method according to any one of claims 3 to 5 and 7, wherein the organic solvent is contained in an amount of 20% by weight or more relative to the ink.

9. The measurement adjustment method according to any one of claims 1 to 8, characterized in that the base material is coated with a liquid-repellent coating material having liquid repellency to the ink.

10. The measurement adjustment method according to any one of claims 1 to 9, wherein in the deriving step,

the diameter of the drop of ink is extracted from the image,

deriving a volume of ink on the substrate using at least the extracted diameter,

11. The measurement adjustment method according to any one of claims 1 to 10, further comprising the adjustment step of: and adjusting the ejection amount from the ink ejection head based on the ejection amount of the ink derived in the deriving step.

12. The measurement adjustment method according to claim 11, wherein the measurement adjustment method is used when forming at least any one of a light-emitting layer, a hole-injecting layer, and a hole-transporting layer among functional layers constituting an organic EL display panel.

13. An ink ejection amount measurement and adjustment device for an ink ejection head, using the measurement and adjustment method according to any one of claims 1 to 12.

14. A panel manufacturing system of an organic EL display panel, comprising the ink ejection amount measurement and adjustment device according to claim 13.

15. A method for manufacturing an organic EL display panel, using the measurement adjustment method according to any one of claims 1 to 12.

16. A method of manufacturing an organic EL display panel using the panel manufacturing system of claim 14.

17. An ink, which is used for the measurement adjustment method according to any one of claims 1 to 12,

18. An ink, which is used in the ink ejection amount measurement and adjustment device according to claim 13,

19. An ink, characterized by being used in the panel manufacturing system of an organic EL display panel according to claim 14,

20. The ink according to any one of claims 17 to 19, wherein the organic solvent is contained in an amount of 20 wt% or more relative to the ink.

21. The ink according to any one of claims 17 to 20, wherein the ink is maintained in a certain proportion to the volume before drying after drying for a predetermined time.

22. An organic EL display panel having a functional layer formed using the ink according to any one of claims 17 to 21.