JP6102064B2 - Display device - Google Patents

Description

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

  There are various types of display devices. One of them is a display device using an organic EL (Electro Luminescence) element as a light source of a pixel. This display device is arranged at equal intervals along the first direction between the support substrate, the partition wall composed of a plurality of partition wall members 1 extending in the first direction X, and between the partition wall members 1. A plurality of organic EL elements are included (see FIG. 6).

  The organic EL element is configured by laminating a first electrode, one or more functional layers, and a second electrode in this order from the support substrate side.

  The functional layer of the organic EL element can be formed by a coating method. For example, the functional layer is formed by supplying ink containing a material to be the functional layer to the concave portion between the partition wall member 1 and the partition wall member 1 and further solidifying it. The ink is supplied by, for example, a nozzle printing method. After forming the functional layer, a plurality of organic EL elements can be formed on the support substrate by further forming the upper electrode by a predetermined method (see, for example, Patent Document 1).

  FIG. 6 is a diagram schematically illustrating an aspect when ink is applied using a nozzle printing apparatus including a plurality of nozzles. The nozzle printing apparatus includes a plurality of nozzles 2 arranged at predetermined intervals in the arrangement direction (in the embodiment shown in FIG. 6, a direction perpendicular to the first direction X). While ejecting predetermined ink from each nozzle 2, the nozzle 2 is scanned in one or the other of the first direction X (hereinafter sometimes referred to as a scanning direction X), so When the ink is supplied and solidifies, the band-shaped thin film 3 is formed. By one scan of the nozzle 2, the strip-shaped thin film 3 is formed by the number of the nozzles 2.

  When the nozzle 2 is scanned from one end to the other end in the scanning direction, the nozzle 2 is then moved in a direction perpendicular to the scanning direction X (hereinafter sometimes referred to as a coating direction Y). One of the application directions Y may be referred to as the front (downward in FIG. 6) and the other of the application directions Y as the rear (upward in FIG. 6). In the forward movement of the nozzle 2, the nozzle 2 is moved forward by the number of rows corresponding to the number of nozzles (in the form shown in FIG. 6, the nozzle 2 moves by a distance of 5 rows). By alternately repeating the movement in the scanning direction X and the forward movement in the application direction Y, ink can be applied between all the partition members 1.

JP 2009-119395 A

  When ink is applied using a plurality of nozzles 2, periodicity appears in the properties of the coating film. This period corresponds to the number of nozzles. For example, the film thickness of the coating film periodically varies corresponding to the number of nozzles. A possible cause of this phenomenon is that the amount of ink discharged from each nozzle varies in a very small amount. This is because even if the amount of ink ejected from each nozzle is set to the same amount, it is difficult to completely match the amount of ink ejected from each nozzle. In addition, even if the nozzles are arranged at equal intervals, it is difficult to completely match the intervals of the nozzles, so the ink supply position between the partition members may be shifted depending on the nozzles. It is considered that this appears as periodicity in the properties of the coating film.

  As described above, when ink is supplied using a nozzle printing apparatus having a plurality of nozzles, due to the configuration and performance of the apparatus, periodicity appears in the properties of the coating film, and so-called unevenness occurs. Such uneven stripes are visually recognized as light emission unevenness in the display device. In particular, when periodic light emission unevenness occurs, it is easy for the human eye to visually recognize the display quality.

  Accordingly, an object of the present invention is to provide a display device capable of suppressing the occurrence of periodic stripe unevenness even when a nozzle printing device having a plurality of nozzles is used.

The present invention includes a support substrate,
On the support substrate, a plurality of organic EL elements arranged in a matrix at predetermined intervals in a first direction and a second direction intersecting the first direction,
An insulating film provided on the support substrate, wherein openings are formed at positions corresponding to the plurality of organic EL elements, and each organic EL element is individually defined by the openings;
A partition wall formed of a plurality of partition wall members disposed between the organic EL elements adjacent to each other in the second direction on the insulating film and extending in the first direction at equal intervals in the second direction; A display device comprising:
When an opening having a specific area provided in the center of the partition wall member adjacent in the second direction is virtually set as a reference opening, each opening has a center in the second direction. Deviating in the second direction with respect to the reference opening and / or its area is different with respect to the reference opening;
The degree to which each opening is displaced in the second direction and the degree to which the area is different relates to a display device that is set at random.

The present invention also provides a support substrate and a plurality of organic EL elements arranged in a matrix at predetermined intervals in the first direction and the second direction intersecting the first direction on the support substrate. An opening formed at a position corresponding to the plurality of organic EL elements, each of the organic EL elements being individually defined by the opening; and the insulating film on the insulating film; Manufacturing of a display device comprising: a partition wall formed of a plurality of partition wall members disposed between organic EL elements adjacent to each other in the second direction and extending in the first direction at equal intervals in the second direction. A method,
Preparing a support substrate provided with pixel electrodes of the plurality of organic EL elements and the insulating film arranged so that the pixel electrodes are exposed from the openings;
Forming a plurality of partition members on the insulating film and providing the partition;
A step of forming a predetermined functional layer of the organic EL element by supplying a predetermined ink between the partition members by a nozzle printing method and solidifying the ink;
Forming an upper electrode on the functional layer,
In the step of preparing the support substrate, each opening is provided in the center of the partition wall member adjacent in the second direction, and an opening having a specific area is used as a reference opening. The center of which is shifted in the second direction with respect to the reference opening, and / or the area is different from the reference opening, and the degree and area where each opening is shifted in the second direction. The present invention relates to a method of manufacturing a display device, in which a support substrate provided with a randomly set insulating film is prepared.

  ADVANTAGE OF THE INVENTION According to this invention, even if it uses a nozzle printing apparatus provided with a some nozzle, the display apparatus which can suppress generation | occurrence | production of a periodic stripe unevenness can be provided.

It is a top view which shows typically the light-emitting device 21 of this embodiment. FIG. 3 is a cross-sectional view schematically showing the light emitting device 21 in an enlarged manner. It is a figure which exaggerates and shows the shape of an insulating film, a functional layer, etc. about the section of light emitting device 21. It is a graph of the image of the film thickness of the functional layer at the center of the opening when ΔS and ΔL are set randomly. This is a graph of the image of the thickness of the functional layer at the center of the opening when ΔS and ΔL are zero. It is a figure which shows typically the aspect when apply | coating ink using a nozzle printing apparatus provided with a some nozzle.

  The display device of the present invention includes a support substrate and a plurality of the substrate arranged in a matrix at predetermined intervals in the first direction and the second direction intersecting the first direction on the support substrate. An organic EL element; an insulating film provided on the support substrate; wherein an opening is formed at a position corresponding to the plurality of organic EL elements, and each organic EL element is individually defined by the opening; and on the insulating film And a partition comprising a plurality of partition members extending in the first direction and spaced between the organic EL elements adjacent to each other in the second direction. When an opening having a specific area provided in the center of the partition wall member adjacent in the second direction is virtually set as a reference opening, each opening is in the second direction. The center of And / or the area thereof is different from that of the reference opening, the degree of deviation of each of the openings in the second direction, and the degree of difference in area are as follows: It is a display device set at random.

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

<Configuration of light emitting device>
First, the structure of the light emitting device will be described. FIG. 1 is a plan view schematically showing the light emitting device 21 of this embodiment, and FIG. 2 is a cross-sectional view schematically showing the light emitting device 21 in an enlarged manner. The light emitting device 21 mainly includes a support substrate 11 and a plurality of organic EL elements 22 provided on the support substrate.

  In the present embodiment, the plurality of organic EL elements 22 are arranged in a matrix on the support substrate 11 with a predetermined interval between the first direction X and the second direction Y that intersects the first direction X. Is done. In the present embodiment, the organic EL elements 22 are arranged at equal intervals in the first direction X.

  In the present embodiment, the first direction X and the second direction Y are directions perpendicular to the thickness direction Z of the support substrate 11. In the present embodiment, the first direction X and the second direction Y are directions perpendicular to each other. Hereinafter, the thickness direction Z of the support substrate 11 may be simply referred to as the thickness direction Z.

  An insulating film 15 that individually defines each organic EL element 22 is provided on the support substrate. Openings are formed in the insulating film 15 at positions corresponding to the plurality of organic EL elements. Each organic EL element 22 is provided at a portion where an opening of the insulating film 15 is formed when viewed from one side in the thickness direction Z (hereinafter, sometimes referred to as a plan view). That is, the part where the opening is provided in plan view corresponds to the part where the organic EL element is provided. As will be described later, the functional layer constituting the organic EL element is formed so as to be continuous with the organic EL element 22 adjacent in the first direction X, and is physically continuous, but the insulating film 15 described above. Thus, the organic EL elements 22 adjacent in the first direction X are electrically insulated.

  Since the openings of the insulating film 15 are formed at positions where the respective organic EL elements 22 are provided, the openings are arranged in a matrix like the organic EL elements 22. Thus, openings are formed in the insulating film 15 in a matrix. In other words, the insulating film 15 is formed in a lattice shape in plan view. The opening of the insulating film 15 is formed so as to substantially coincide with a pixel electrode 12 described later in a plan view, and is formed in, for example, a substantially rectangular shape, a substantially circular shape, or a substantially elliptical shape. The lattice-like insulating film 15 is mainly formed in a region excluding the pixel electrode 12 in a plan view, and a part thereof is formed to cover the periphery of the pixel electrode 12.

  In the present embodiment, a partition wall 17 including a plurality of partition wall members 20 extending in the first direction X is provided on the insulating film 15. Each partition member 20 is disposed between organic EL elements adjacent in the second direction Y. In the present embodiment, the partition wall members 20 are arranged at an equal interval in the second direction Y. As described above, in this embodiment, the so-called stripe-shaped partition wall 17 is provided on the insulating film 15.

  The organic EL element 22 is provided in a section defined by the partition wall 17. In the present embodiment, the plurality of organic EL elements 22 are provided between the partition members 20 adjacent to each other in the second direction Y (that is, the recesses 18), and a predetermined interval is provided in the first direction X between the partition members 20. It is arranged with a gap. The organic EL elements 22 do not have to be physically separated from each other, and may be electrically insulated so that they can be individually driven. Therefore, some layers (electrodes and functional layers) constituting the organic EL element may be physically connected to other organic EL elements.

  The organic EL element 22 is configured by arranging the first electrode 12, the functional layers 13 and 14, and the second electrode 16 in this order from the support substrate 11 side. In the present specification, the first electrode 12 is referred to as a pixel electrode 12, and the second electrode 16 is referred to as an upper electrode 16.

  The pixel electrode 12 and the upper electrode 16 constitute a pair of electrodes composed of an anode and a cathode. That is, one of the pixel electrode 12 and the upper electrode 16 is provided as an anode, and the other is provided as a cathode. Of the pixel electrode 12 and the upper electrode 16, the pixel electrode 12 is disposed closer to the support substrate 11, and the upper electrode 16 is disposed farther from the support substrate 11 than the pixel electrode 12.

  The organic EL element 22 includes one or more functional layers. In this specification, the functional layer means all layers sandwiched between the pixel electrode 12 and the upper electrode 16. The organic EL element 22 includes at least one light emitting layer as a functional layer. In addition, a predetermined layer is provided between the electrodes as needed without being limited to the light emitting layer. For example, a hole injection layer, a hole transport layer, and an electron block layer are provided as a functional layer between the anode and the light emitting layer. In addition, a hole blocking layer, an electron transport layer, an electron injection layer, and the like are provided as a functional layer between the light emitting layer and the cathode.

  The organic EL element 22 of this embodiment includes a hole injection layer 13 as a functional layer between the pixel electrode 12 and the light emitting layer 14.

  Hereinafter, as one embodiment, a pixel electrode 12 that functions as an anode, a hole injection layer 13, a light emitting layer 14, and an upper electrode 16 that functions as a cathode are stacked in this order from the support substrate 11 side. The configured organic EL element 22 will be described.

  The light emitting device 21 of the present embodiment is an active matrix type device, and the pixel electrode 12 is provided for each organic EL element 22 in order to enable each organic EL element 22 to be driven individually. That is, the same number of pixel electrodes 12 as the number of organic EL elements 22 are provided on the support substrate 11. For example, the pixel electrode 12 has a thin film shape and is formed in a substantially rectangular shape in plan view. The pixel electrodes 12 are provided in a matrix on the support substrate 11 corresponding to the positions where each organic EL element is provided. The plurality of pixel electrodes 12 are arranged at predetermined intervals in the first direction X and at predetermined intervals in the second direction Y. The pixel electrodes 12 are provided between the partition members 20 adjacent to each other in the second direction Y in plan view, and are disposed between the partition members 20 with a predetermined interval in the first direction X.

  As described above, the lattice-like insulating film 15 is mainly formed in a region excluding the pixel electrode 12 in a plan view, and a part thereof is formed to cover the periphery of the pixel electrode 12. That is, an opening is formed in the insulating film 15 on the pixel electrode 12, and the surface of the pixel electrode 12 is exposed from the insulating film 15 through this opening.

  The hole injection layer 13 is disposed so as to extend in the first direction X in a region sandwiched between the partition members 20. That is, the hole injection layer 13 is formed in a strip shape in the recess 18 defined by the partition wall member 20 adjacent in the second direction Y, and continuously over the organic EL elements 22 adjacent in the first direction X. Is formed.

  The light emitting layer 14 is disposed so as to extend in the first direction X in a region between the partition members 20. That is, the light emitting layer 14 is formed in a strip shape in the recess 18 defined by the partition member 20 adjacent in the second direction Y, and is continuously formed over the organic EL elements adjacent in the first direction X. Yes. The band-shaped light emitting layer 14 is laminated on the band-shaped hole injection layer 13.

  Although the present invention can also be applied to a monochrome display device, in this embodiment, a color display device will be described as an example. In the case of a color display device, three types of organic EL elements that emit any one of red, green, and blue light are provided on the support substrate 11. The color display device is realized, for example, by repeatedly arranging the following rows (I), (II), and (III) in this order in the second direction Y.

(I) A row in which a plurality of organic EL elements 22R emitting red light are arranged in the first direction X with a predetermined interval.
(II) A row in which a plurality of organic EL elements 22G that emit green light are arranged in the first direction X at a predetermined interval.
(III) A row in which a plurality of organic EL elements 22B emitting blue light are arranged in the first direction X with a predetermined interval.

  When three types of organic EL elements having different emission colors are formed as described above, a light emitting layer having a different emission color is usually provided for each type of element. In the present embodiment, the following rows (i), (ii), and (iii) are repeatedly arranged in the second direction Y in this order.

(I) A row provided with a light emitting layer 14R that emits red light.
(Ii) A row in which the light emitting layer 14G emitting green light is provided.
(Iii) A row in which the light emitting layer 14B emitting blue light is provided.

  In this case, three types of strip-shaped light emitting layers 14R, 14G, and 14B extending in the first direction X are sequentially stacked on the hole injection layer 13 with two rows in the second direction Y, respectively. The

  The upper electrode 16 is provided on the light emitting layer 14. In the present embodiment, the upper electrode 16 is continuously formed across the plurality of organic EL elements 22 and provided as a common electrode for the plurality of organic EL elements. The upper electrode 16 is formed not only on the light emitting layer 14 but also on the partition wall 17, and is formed on one surface so that the electrode on the light emitting layer 14 and the electrode on the partition wall 17 are connected.

  FIG. 3 is a diagram illustrating exaggerated shapes of an insulating film, a functional layer, and the like in the cross section of the light emitting device 21. In FIG. 3, the pixel electrode 12 and the upper electrode 16 are not shown for easy understanding.

  In the present embodiment, when an opening having a specific area provided in the center of the partition wall member adjacent in the second direction is virtually set as a reference opening, each of the openings has its second The center of the direction is shifted in the second direction with respect to the reference opening and / or the area thereof is different with respect to the reference opening.

  As described above, in the present embodiment, the interval p in the second direction Y of the partition wall member 20 is an equal interval, but the areas and / or positions of the plurality of openings formed in the insulating film 15 are each organic EL. Different for each element.

  In the present embodiment, the reference opening is virtually set. Let So be the area of this reference opening in plan view. Further, the position of the reference opening is set so that the center in the second direction Y coincides with the center in the second direction Y of the pair of partition members 20 facing the opening. This virtually set reference opening corresponds to, for example, an opening set in the design of a normal display device.

  Hereinafter, the area of a specific opening that is arbitrarily focused on among the plurality of openings is described as S, and the difference “So−S” between the reference area and the area of the specific opening is described as ΔS. When the area S of the specific opening is larger than the area So of the reference opening, ΔS takes a positive value. Conversely, when the area S of the specific opening is smaller than the area So of the reference opening, ΔS takes a negative value.

  If the center position in the second direction Y between the opposing partition members 20 is O, the center position O corresponds to the center position in the second direction Y of the reference opening. When the center position O is used as a reference, a deviation in the second direction of the center position L in the second direction of the specific opening is described as ΔL. When the center position L is shifted in one of the second directions Y with respect to the center position O, ΔL takes a positive value, and conversely, the center position L is in the second direction with respect to the center position O. When it is shifted to the other of Y, ΔL takes a negative value.

  In the present embodiment, the degree of displacement of each opening in the second direction and the degree of area difference are set randomly. That is, in this embodiment, ΔS and / or ΔL is set randomly for each opening.

  For example, when a random number from 0 to 1 is generated and the value is “ran”, the area S of each opening is set as follows.

S = So + (ran−0.5) × A × So
Here, the symbol “A” is 0.02 to 0.2, and preferably 0.03 to 0.07.

  ΔL is expressed by the following equation, where p is the pitch of the partition members 20 provided at equal intervals in the second direction Y.

ΔL = (ran−0.5) × B × p
Here, the symbol “B” is 0.02 to 0.2, preferably 0.03 to 0.07.

  The random number can be generated based on, for example, the Mersenne Twister method.

  The area of the opening and the position of the opening affect the film thickness of the functional layer at the center position in the second direction Y of the opening. For example, when the area of the opening is increased, the thickness of the functional layer is decreased. Conversely, when the area of the opening is decreased, the thickness of the functional layer is increased. When the center position L in the second direction Y of the opening is shifted from the center position O, the film thickness of the functional layer at the center position L in the second direction Y of the opening changes.

  Therefore, when ΔL and ΔS are set randomly, the film thickness of the functional layer at the center position in the second direction Y of the opening randomly varies. That is, the thickness of the functional layer varies randomly for each organic EL element. As described in the background art, when ink is applied using a nozzle printing apparatus having a plurality of nozzles, periodicity is seen in the thickness of the formed thin film. When ΔS and ΔL are set at random as shown in Fig. 6, the functional layer thickness can be changed randomly for each organic EL element, thus reducing the periodicity of the functional layer thickness. can do.

FIG. 4 is a graph showing the calculation result of the film thickness of the functional layer at the center of the opening when ΔS and ΔL are set randomly. FIG. 5 is a graph of an image of the thickness of the functional layer at the center of the opening when ΔS and ΔL are zero.
In FIG. 5, the periodicity appears in the film thickness with the number of nozzles (8 nozzles) as a period. However, by setting ΔS and ΔL at random, the periodicity of the film thickness can be relaxed. Understood.

  Even in the uneven stripe, it becomes easier for the human eye to perceive it, especially if it is periodic, but by reducing the periodicity as described above, the extent that it is visually recognized as uneven stripes can be reduced, The display quality as a display device can be improved.

<Method for manufacturing light emitting device>
Next, a method for manufacturing the light emitting device will be described.

  The method for manufacturing a light-emitting device according to the present invention is arranged in a matrix at predetermined intervals in a first direction and a second direction intersecting the first direction on the support substrate and the support substrate. A plurality of organic EL elements, and an insulating film provided on the support substrate, wherein openings are formed at positions corresponding to the plurality of organic EL elements, and the organic EL elements are individually defined by the openings; A partition wall, which is disposed between organic EL elements adjacent in the second direction on the insulating film and includes a plurality of partition wall members extending in the first direction at an equal interval in the second direction. A method of manufacturing a display device comprising: preparing a support substrate provided with a pixel electrode of a plurality of organic EL elements and the insulating film arranged so that the pixel electrode is exposed from the opening; On the insulating film Forming a plurality of partition members and providing partition walls; supplying a predetermined ink by a nozzle printing method between the partition members and solidifying the ink; thereby forming a predetermined functional layer of the organic EL element; Forming an upper electrode on the functional layer, and in the step of preparing the support substrate, an opening provided in the center of the partition wall member adjacent in the second direction and having a specific area is used as a reference. Each opening has its center in the second direction shifted in the second direction with respect to the reference opening, and / or its area is relative to the reference opening. In contrast, the degree of displacement of the respective openings in the second direction and the degree of difference in area relate to a method of manufacturing a display device, in which a support substrate provided with a randomly set insulating film is prepared.

(Process for preparing support substrate)
In this step, a support substrate 11 is prepared in which pixel electrodes 12 of a plurality of organic EL elements and the insulating film 15 arranged so that the pixel electrodes 12 are exposed from the openings are provided thereon. In the case of an active matrix display device, a substrate on which circuits for individually driving a plurality of organic EL elements are formed in advance can be used as the support substrate 11. For example, a substrate on which a TFT (Thin Film Transistor), a capacitor, and the like are formed in advance can be used as the support substrate. The pixel electrode 12 and the insulating film 15 may be formed in this step as follows to prepare the support substrate 11 on which the pixel electrode 12 and the insulating film 15 are provided. The support substrate 11 may be prepared by obtaining from the market the support substrate 11 on which the insulating film 15 is previously provided.

  First, a plurality of pixel electrodes 12 are formed in a matrix on the support substrate 11. The pixel electrode 12 is formed, for example, by forming a conductive thin film on one surface of the support substrate 11 and patterning it in a matrix by a photolithography method. In addition, for example, a mask in which an opening is formed in a predetermined portion is arranged on the support substrate 11, and the pixel electrode 12 is formed by selectively depositing a conductive material on the predetermined portion on the support substrate 11 through the mask. A pattern may be formed. The material of the pixel electrode 12 will be described later.

  As described above, the area and / or position of the opening of the insulating film 15 varies by ΔS and ΔL, but the pixel electrode 12 has an opening in the insulating film 15 so that the periphery of the pixel electrode 12 is covered with the insulating film. It is formed corresponding to the size and the position.

  Next, a lattice-like insulating film 15 is formed on the support substrate 11. In this step, if each opening provided in the center of the partition wall member 20 adjacent to the second direction Y and having a specific area is a reference opening, each opening is a center in the second direction Y. Is shifted in the second direction with respect to the reference opening, and / or the area thereof is different from that of the reference opening, and the degree and area of each opening is shifted in the second direction. The degree of forming the insulating film is set at random. That is, the insulating film 15 in which ΔS and / or ΔL described above is set randomly for each opening is formed.

The insulating film 15 is made of an organic material or an inorganic material. Examples of the organic material constituting the insulating film 15 include resins such as acrylic resin, phenol resin, and polyimide resin. In addition, examples of the inorganic material forming the insulating film 15 include SiO _x and SiN _x .

  In the case of forming the insulating film 15 made of an inorganic material, for example, a thin film made of an inorganic material is formed on one surface by a plasma CVD method, a sputtering method or the like, and then a predetermined portion is removed to form the lattice-shaped insulating film 15. The predetermined portion is removed by, for example, a photolithography method.

  When forming the insulating film 15 made of an organic material, first, for example, a positive or negative photosensitive resin is applied to one surface, and a predetermined portion is exposed and developed. Further, by curing this, a lattice-like insulating film 15 is formed. Note that a photoresist can be used as the photosensitive resin.

  Next, the partition wall 17 is formed. That is, a plurality of partition members 20 are formed on the insulating film 15 to provide the partition walls 17. In this step, the partition member 20 is formed with an equal interval in the second direction Y, and the partition 17 composed of the plurality of partition members 20 is formed.

  The partition wall 17 can be formed in a stripe shape in the same manner as the method of forming the insulating film 15 using, for example, the material exemplified as the material of the insulating film 15.

  The partition wall 17 is preferably made of an organic material. In order to retain the ink supplied to the recess 18 surrounded by the partition wall 17 in the recess 18, the partition wall preferably exhibits liquid repellency. In general, an organic material has a liquid repellency with respect to ink rather than an inorganic material. Therefore, by forming a partition wall with an organic material, the ability to retain ink in the recess 18 can be enhanced.

  The shape and arrangement of the partition walls 17 are appropriately set according to the specifications of the display device such as the number of pixels and the resolution, the ease of manufacturing, and the like. For example, the width L1 of the partition member 20 in the second direction Y is about 5 μm to 50 μm, the height L2 of the partition member 20 is about 0.5 μm to 5 μm, and the width L3 of the recess 18 in the second direction Y. Is about 10 μm to 200 μm. The width of the pixel electrode 12 in the first direction X and the second direction Y is about 10 μm to 400 μm, respectively.

(Process for forming functional layer)
In this step, a predetermined functional layer of the organic EL element is formed by supplying a predetermined ink between the partition members by a nozzle printing method and solidifying the ink. The predetermined ink means an ink containing a material that becomes a functional layer (in this embodiment, a hole injection layer and a light emitting layer). In this step, when a plurality of functional layers are provided, at least one layer is formed by a nozzle printing method.

  In this embodiment, the hole injection layer 13 common to all organic EL elements is formed. In the present embodiment, the hole injection layer ink is supplied by a nozzle printing method as a coating method capable of selectively supplying the hole injection layer ink.

  Hereinafter, this process will be described with reference to FIG. FIG. 6 is a diagram schematically showing an operation when ink is applied by the nozzle printing method. Note that FIG. 6 is the same as the drawing cited in the problem section, but the display device of the present embodiment and the conventional display device described in the problem section have the size and / or arrangement of the openings. Different.

  In the nozzle printing method, the ink for the hole injection layer is supplied to each row (each concave portion 18) by one stroke. That is, when the nozzle 2 is reciprocated in the first direction X while the liquid columnar hole injection layer ink is discharged from the nozzle disposed above the support substrate 11, Then, the hole injection layer ink is supplied to each row by moving the support substrate in the second direction Y by a predetermined distance. For example, when the nozzle 2 is turned back and forth, the ink for the hole injection layer can be supplied to all rows by moving the support substrate in the second direction Y by the number of rows corresponding to the number of nozzles. Instead of moving the support substrate in the second direction Y, the nozzle 2 may be moved in the second direction Y.

More specifically, the following steps (1) to (4) are repeated in this order while the liquid columnar hole injection layer ink is ejected from the nozzle 2, so that all the partition wall members 20 (recesses 18 are formed). ) Can be supplied with an ink for a hole injection layer.
(1) A step of moving the nozzle 2 from one end to the other end in the first direction X.
(2) A step of moving the support substrate 11 in one of the second directions Y by the number of rows corresponding to the number of nozzles.
(3) A step of moving the nozzle 2 from the other end in the first direction X to one end.
(4) A step of moving the support substrate in one of the second directions Y by the number of rows corresponding to the number of nozzles.

  As described above, by supplying the hole injection layer ink by the nozzle printing method, a thin film made of the hole injection layer ink is formed.

  As described above, in the present embodiment, the degree to which each opening is displaced in the second direction and the degree to which the area is different are set at random. By providing such an opening, even if ink is applied by the nozzle printing method, the periodicity of the film thickness of the functional layer formed between the partition members 20 is relaxed as shown in FIG.

(Step of forming the light emitting layer)
Next, a light emitting layer is formed. As described above, when producing a color display device, it is necessary to produce three types of organic EL elements. Therefore, it is necessary to coat the material of the light emitting layer for each row. For example, when three types of light emitting layers are formed for each row, red ink containing a material that emits red light, green ink containing a material that emits green light, and blue ink containing a material that emits blue light, respectively. It is necessary to apply in the direction Y of 2 with an interval of 2 rows. By sequentially applying the red ink, the green ink, and the blue ink to predetermined rows, each light emitting layer can be coated and formed.

  As a method for sequentially applying the red ink, the green ink, and the blue ink to a predetermined line, any method may be used as long as the ink can be selectively supplied between the partition members. For example, the ink can be supplied by an inkjet printing method, a nozzle printing method, a relief printing method, an intaglio printing method, or the like. As a method for supplying ink, a method capable of supplying ink uniformly in a short time is preferable, and from this viewpoint, a nozzle printing method is preferable. In the present embodiment, ink is supplied by a nozzle printing method as in the method for forming the hole injection layer described above.

More specifically, the following steps (1) to (4) are repeated in this order while the liquid columnar red ink is discharged from the nozzle 2, so that two rows are spaced in the second direction Y. Red ink can be supplied between the partition members 20 (recesses 18).
(1) A step of moving the nozzle 2 from one end to the other end in the first direction X.
(2) A step of moving the support substrate 11 in one of the second directions Y by the number of nozzles × 3 rows.
(3) A step of moving the nozzle 2 from the other end in the first direction X to one end.
(4) A step of moving the support substrate 11 in one of the second directions Y by the number of nozzles × 3 rows.

  By supplying green ink and blue ink respectively in the same manner as the above-mentioned red ink, green ink and blue ink are supplied between the partition members 20 (recesses 18) with an interval of two lines in the second direction Y, respectively. can do.

  Luminescent materials used for red ink, green ink, and blue ink will be described later. Each ink may contain a polymerizable compound that can be polymerized by applying energy. As the ink, red ink, green ink, and blue ink containing a light-emitting material having a polymerizable group that can be polymerized by applying energy as a polymerizable compound may be used. In addition to the light emitting material, a red ink, a green ink, and a blue ink containing a polymerizable compound having a polymerizable polymerizable group may be used.

  Polymerizable groups include vinyl, ethynyl, butenyl, acryloyl, acryloylamino, methacryloyl, methacryloylamino, vinyloxy, vinylamino, silanol, cyclopropyl, cyclobutyl, epoxy, oxetanyl Group, diketenyl group, epithio group, lactonyl group, lactamnyl group and the like.

  Polymerizable compounds include PDA (N, N'-tetraphenyl-1,4-phenylenediamine) derivatives having a polymerizable group and TPD (N, N'-bis (3-methylphenyl) having a polymerizable group. ) -N, N'-bis (phenyl) -benzidine) derivatives, NPD with polymerizable groups (N, N'-bis (naphthalen-1-yl) -N, N'-bis (phenyl) -benzidine) Derivatives, triphenylamine acrylate, triphenylenediamine acrylate, phenylene acrylate, bisphenoxyethanol full orange acrylate (trade name BPEF-A, manufactured by Osaka Gas Chemical Company), dipentaerythritol hexaacrylate (KAYARD DPHA, manufactured by Nippon Kayaku), trispenta Erythritol octaacrylate (manufactured by Guangei Chemical) 1,4-butanediol diacrylate (manufactured by Alfa Aesar), Aron oxetane (OXT121; cross-linking agent manufactured by Toagosei Co., Ltd.), etc. You can gel, phenyl fluorene acrylate is preferable among these.

  As described above, in the present embodiment, the degree to which each opening is displaced in the second direction and the degree to which the area is different are set at random. By providing such an opening, even if ink is applied by the nozzle printing method, the periodicity of the thickness of the thin film formed between the partition members 20 is relaxed as shown in FIG.

  After forming the light emitting layer, a predetermined organic layer, an inorganic layer, or the like is formed by a predetermined method as necessary. These may be formed using a predetermined coating method such as a printing method, an ink jet method, a nozzle printing method, or a predetermined dry method.

(Process of forming the upper electrode)
Next, an upper electrode is formed. As described above, in this embodiment, the upper electrode is formed on the entire surface of the support substrate. Thereby, a plurality of organic EL elements can be formed on the substrate.

  As described above, in the present embodiment, the degree to which each opening is displaced in the second direction and the degree to which the areas are different are set at random. By providing such an opening, even if ink is applied by the nozzle printing method, the periodicity of the film thickness of the hole injection layer and the light emitting layer formed between the partition members 20 as shown in FIG. Alleviated.

  Even if it is periodic, it will be more easily perceived by the human eye if it is periodic. However, by reducing the periodicity as described above, the degree of visible irregularity can be reduced, and the display device As a result, display quality can be improved.

<Configuration of organic EL element>
As described above, the organic EL element can have various layer configurations. Hereinafter, the layer structure of the organic EL element, the configuration of each layer, and the method of forming each layer will be described in more detail.

As described above, the organic EL element includes a pair of electrodes (pixel electrode and upper electrode) composed of an anode and a cathode, and one or more functional layers provided between the electrodes. As a layer, at least one light emitting layer is provided. The organic EL element may include a layer containing an inorganic substance and an organic substance, an inorganic layer, and the like. The organic substance constituting the organic layer may be a low molecular compound or a high molecular compound, or a mixture of a low molecular compound and a high molecular compound. The organic layer preferably contains a polymer compound, and preferably contains a polymer compound having a polystyrene-equivalent number average molecular weight of 10 ³ to 10 ⁸ .

  Examples of the functional layer provided between the cathode and the light emitting layer include an electron injection layer, an electron transport layer, and a hole blocking layer. When both the electron injection layer and the electron transport layer are provided between the cathode and the light emitting layer, the layer close to the cathode is called an electron injection layer, and the layer close to the light emitting layer is called an electron transport layer. Examples of the functional layer provided between the anode and the light emitting layer include a hole injection layer, a hole transport layer, and an electron block layer. When both the hole injection layer and the hole transport layer are provided, a layer close to the anode is referred to as a hole injection layer, and a layer close to the light emitting layer is referred to as a hole transport layer.

An example of a layer structure that can be taken by the organic EL element of the present embodiment is shown below.
a) anode / light emitting layer / cathode b) anode / hole injection layer / light emitting layer / cathode c) anode / hole injection layer / light emitting layer / electron injection layer / cathode d) anode / hole injection layer / light emitting layer / Electron transport layer / cathode e) anode / hole injection layer / light emitting layer / electron transport layer / electron injection layer / cathode f) anode / hole transport layer / light emitting layer / cathode g) anode / hole transport layer / light emitting layer / Electron injection layer / cathode h) anode / hole transport layer / light emitting layer / electron transport layer / cathode i) anode / hole transport layer / light emitting layer / electron transport layer / electron injection layer / cathode j) anode / hole Injection layer / hole transport layer / light emitting layer / cathode k) anode / hole injection layer / hole transport layer / light emitting layer / electron injection layer / cathode l) anode / hole injection layer / hole transport layer / light emitting layer / Electron transport layer / cathode m) anode / hole injection layer / hole transport layer / light emitting layer / electron transport layer / electron injection layer / cathode n) anode / light emitting layer / electron injection layer / cathode o) anode / Photo layer / electron transport layer / cathode p) anode / light emitting layer / electron transport layer / electron injection layer / cathode (here, the symbol “/” indicates that the layers sandwiching the symbol “/” are stacked adjacent to each other) The same shall apply hereinafter.)

The organic EL element of the present embodiment may have two or more light emitting layers. In any one of the layer configurations of a) to p) above, when the laminate sandwiched between the anode and the cathode is referred to as “structural unit A”, the configuration of the organic EL element having two light emitting layers is obtained. And the layer structure shown in the following q). Note that the two (structural unit A) layer structures may be the same or different.
q) Anode / (structural unit A) / charge generating layer / (structural unit A) / cathode If “(structural unit A) / charge generating layer” is “structural unit B”, it has three or more light emitting layers. Examples of the structure of the organic EL element include the layer structure shown in the following r).
r) anode / (structural unit B) x / (structural unit A) / cathode The symbol “x” represents an integer of 2 or more, and (structural unit B) x is a stack in which the structural unit B is stacked in x stages. Represents the body. A plurality of (structural units B) may have the same or different layer structure.

  Here, the charge generation layer is a layer that generates holes and electrons by applying an electric field. Examples of the charge generation layer include a thin film made of vanadium oxide, indium tin oxide (abbreviated as ITO), molybdenum oxide, or the like.

  In the organic EL element, the anode of the pair of electrodes composed of the anode and the cathode may be disposed closer to the support substrate than the cathode, and the cathode may be disposed closer to the support substrate than the anode. And you may provide in a support substrate. For example, in the above a) to r), each layer may be laminated on the support substrate in order from the right side to constitute an organic EL element, or each layer may be laminated on the support substrate in order from the left side to constitute an organic EL element. May be. The order of the layers to be laminated, the number of layers, and the thickness of each layer can be appropriately set in consideration of the light emission efficiency and the element lifetime.

  Next, the material and forming method of each layer constituting the organic EL element will be described more specifically.

<Anode>
In the case of an organic EL element having a configuration in which light emitted from the light emitting layer is emitted outside the element through the anode, an electrode exhibiting optical transparency is used for the anode. As the electrode exhibiting light transmittance, a thin film of metal oxide, metal sulfide, metal or the like can be used, and an electrode having high electrical conductivity and light transmittance is preferably used. Specifically, a thin film made of indium oxide, zinc oxide, tin oxide, ITO, indium zinc oxide (abbreviated as IZO), gold, platinum, silver, copper, or the like is used. Among these, ITO, IZO Or a thin film made of tin oxide is preferably used.

  Examples of a method for producing the anode include a vacuum deposition method, a sputtering method, an ion plating method, and a plating method. Further, as the anode, an organic transparent conductive film such as polyaniline or a derivative thereof, polythiophene or a derivative thereof may be used.

  The film thickness of the anode is appropriately set in consideration of the required characteristics and the simplicity of the film forming process, and is, for example, 10 nm to 10 μm, preferably 20 nm to 1 μm, and more preferably 50 nm to 500 nm.

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

  The film thickness of the cathode is appropriately set in consideration of the required characteristics and the simplicity of the film forming process, and is, for example, 10 nm to 10 μm, preferably 20 nm to 1 μm, and more preferably 50 nm to 500 nm.

  Examples of the method for producing the cathode include a vacuum deposition method, a sputtering method, and a laminating method in which a metal thin film is thermocompression bonded.

<Hole injection layer>
The hole injection material constituting the hole injection layer includes oxides such as vanadium oxide, molybdenum oxide, ruthenium oxide, and aluminum oxide, phenylamine compounds, starburst amine compounds, phthalocyanine compounds, amorphous carbon , Polyaniline, and polythiophene derivatives.

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

<Hole transport layer>
As the hole transport material constituting the hole transport layer, polyvinylcarbazole or a derivative thereof, polysilane or a derivative thereof, a polysiloxane derivative having an aromatic amine in a side chain or a main chain, a pyrazoline derivative, an arylamine derivative, a stilbene derivative, Triphenyldiamine derivative, polyaniline or derivative thereof, polythiophene or derivative thereof, polyarylamine or derivative thereof, polypyrrole or derivative thereof, poly (p-phenylene vinylene) or derivative thereof, or poly (2,5-thienylene vinylene) or Examples thereof include derivatives thereof.

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

<Light emitting layer>
The light emitting layer is usually formed of an organic substance that mainly emits fluorescence and / or phosphorescence, or an organic substance and a dopant that assists the organic substance. The dopant is added, for example, in order to improve the luminous efficiency and change the emission wavelength. In addition, the organic substance which comprises a light emitting layer may be a low molecular compound or a high molecular compound, and when forming a light emitting layer by the apply | coating method, it is preferable that a light emitting layer contains a high molecular compound. The number average molecular weight in terms of polystyrene of the polymer compound constituting the light emitting layer is, for example, about 10 ³ to 10 ⁸ . Examples of the light emitting material constituting the light emitting layer include the following dye materials, metal complex materials, polymer materials, and dopant materials.

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

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

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

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

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

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

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

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

  In the case where there are a plurality of functional layers that can be formed by a coating method among the functional layers, it is preferable to form all the functional layers by using the coating method. At least one of the plurality of functional layers may be formed by a coating method, and the other functional layers may be formed by a method different from the coating method. Further, even when a plurality of functional layers are formed by a coating method, the plurality of functional layers may be formed by a coating method in which a specific method of the coating method is different. For example, in this embodiment, the hole injection layer and the light emitting layer are formed by a nozzle printing method, but the hole injection layer may be formed by a spin coating method and the light emitting layer may be formed by a nozzle printing method.

  In the coating method, the functional layer is formed by coating and forming an ink containing an organic EL material to be each functional layer. Examples of the ink solvent used at that time include chloroform, methylene chloride, dichloroethane, and the like. Chlorine solvents, ether solvents such as tetrahydrofuran, aromatic hydrocarbon solvents such as toluene and xylene, ketone solvents such as acetone and methyl ethyl ketone, ester solvents such as ethyl acetate, butyl acetate, and ethyl cellosolve acetate, and Water or the like is used.

  Further, as a method different from the coating method, the functional layer may be formed by a vacuum deposition method, a sputtering method, a CVD method, a lamination method, or the like.

DESCRIPTION OF SYMBOLS 1 Partition member 2 Nozzle 3 Thin film 11 Support substrate 12 Pixel electrode 13 Hole injection layer 14 Light emitting layer 15 Insulating film 16 Upper electrode 17 Partition 18 Recess 20 Partition member 21 Light emitting device 22 Organic EL element

Claims (2)

A plurality of organic EL elements arranged in a matrix at predetermined intervals in a first direction and a second direction intersecting the first direction on the support substrate; and the support An opening is provided on the substrate, and an opening is formed at a position corresponding to the plurality of organic EL elements. The insulating film individually defines the organic EL elements through the opening, and the second direction is formed on the insulating film in the second direction. A method of manufacturing a display device, comprising: a partition wall formed of a plurality of partition wall members disposed between adjacent organic EL elements and extending in the first direction at an equal interval in the second direction,
Preparing a support substrate provided with pixel electrodes of the plurality of organic EL elements and the insulating film arranged so that the pixel electrodes are exposed from the openings;
Forming a plurality of partition members on the insulating film and providing the partition;
A step of forming a predetermined functional layer of the organic EL element by supplying a predetermined ink between the partition members by a nozzle printing method and solidifying the ink;
Forming an upper electrode on the functional layer,
In the step of preparing the support substrate, each opening is provided at the center of the partition wall member adjacent in the second direction and has an opening having a specific area as a reference opening. A method of manufacturing a display device, comprising: preparing a support substrate provided with an insulating film which is different from a reference opening and has a different degree of area of each opening. In the step of preparing the support substrate,
Each of the openings has a center in the second direction shifted in the second direction with respect to the reference opening,
The method for manufacturing a display device according to claim 1 , wherein a support substrate provided with an insulating film in which the degree of deviation of each opening in the second direction is set at random is prepared.

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