JP5796422B2 - Light emitting device - Google Patents

Description

  The present invention relates to a light emitting device and a method for manufacturing the same.

  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 X between the support substrate, the partition wall 20 including a plurality of partition wall members 17 extending in the first direction, and between the partition wall members. A plurality of organic EL elements 22 are included (see FIG. 8).

  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 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 member 17 and the partition member 17 and further solidifying the ink. The ink is supplied by, for example, a nozzle printing method. After the functional layer is formed by the nozzle printing method, 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).

JP 2002-75640 A

  FIG. 8 is a plan view schematically showing a part of the display device. In FIG. 8, the path | route of the nozzle 4 of a nozzle printing apparatus is typically shown using the arrow. As shown in FIG. 8, in the nozzle printing method, ink is applied with a single stroke.

  Hereinafter, with reference to FIG. 8, focusing on one predetermined row, the properties of the coating film formed on the row will be described. In the present specification, the coating film means a thin film that has been solidified after the ink has been applied.

  The present inventors have found that when the coating film is formed by the nozzle printing method, the film thickness of the formed coating film varies. For example, in FIG. 8, when attention is paid to a row in which ink is applied from one end on the right side to the other end on the left side, a phenomenon that the film thickness of the coating film is thicker on the right side is observed. Conversely, focusing on the line where the ink was applied from one end on the left side to the other end on the right side, a phenomenon that the film thickness of the coating film was thicker on the left side was observed. That is, the present inventors have found that the thickness of the coating film decreases as it approaches the lower side from the upper side in the ink application direction. As described above, when the coating film (functional layer) varies in thickness, the emission characteristics of each organic EL element also vary. When each organic EL element emits light, for example, streaks appear every two rows. It may be observed, and the display quality as a display device may deteriorate.

  Accordingly, an object of the present invention is to provide a light emitting device capable of suppressing variations in light emission characteristics of organic EL elements and a method for manufacturing the same when a display device is manufactured by a nozzle printing method.

The present invention includes a support substrate,
A partition wall made of a plurality of partition wall members extending in the first direction on the support substrate;
A plurality of recesses are defined by a pair of partition members facing a second direction perpendicular to the first direction, and a plurality of recesses are arranged at predetermined intervals in the first direction in the respective recesses. A display device comprising an organic EL element,
The plurality of recesses have a plurality of first recesses whose width in the second direction becomes narrower from one end in the first direction toward the other end, and a width in the second direction. The present invention relates to a display device including a plurality of second recesses that become wider from one end portion in the first direction toward the other end portion.

  The present invention also relates to a display device in which the first recesses and the second recesses are alternately arranged in a second direction.

  In the present invention, the arrangement of the concave portions arranged in the order of the first concave portion, the first concave portion, the second concave portion and the second concave portion in the second direction is repeatedly arranged in the second direction. The present invention relates to a display device.

According to another aspect of the present invention, there is provided a pair of a support substrate, a partition wall made of a plurality of partition members extending in the first direction on the support substrate, and a second direction perpendicular to the first direction. A plurality of recesses are defined by the partition member, and a manufacturing method of a display device including a plurality of organic EL elements arranged at predetermined intervals in the first direction in the recesses,
The width of the concave portion in the second direction becomes narrower from one end portion in the first direction toward the other end portion, and the width in the second direction of the concave portion is the first width. A partition wall having a shape forming a plurality of second concave portions that become wider from one end portion in one direction toward the other end portion, and pixel electrodes of the plurality of organic EL elements are provided thereon. Preparing a support substrate;
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 supplying the ink, in a first direction, the present invention relates to a method of manufacturing a display device in which ink is continuously supplied from one wide concave portion to the other narrow concave portion.

  ADVANTAGE OF THE INVENTION According to this invention, when producing a display apparatus by the nozzle printing method, the light-emitting device which can suppress the dispersion | variation in the light emission characteristic of an organic EL element, and its manufacturing method 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. 3 is a plan view exaggeratingly showing the arrangement of partition members 17 of the light emitting device 21. FIG. 3 is a plan view exaggeratingly showing the arrangement of partition members 17 of the light emitting device 21. FIG. It is a figure which shows typically operation | movement when apply | coating ink by the nozzle printing method. It is a figure which shows typically operation | movement when apply | coating ink by the nozzle printing method. 3 is a plan view exaggeratingly showing the arrangement of partition members 17 of the light emitting device 21. FIG. It is a top view which shows a part of display apparatus typically.

  The display device of the present invention has a support substrate, a partition wall made of a plurality of partition wall members extending in the first direction on the support substrate, and a second direction perpendicular to the first direction. A plurality of recesses are defined by a pair of the partition members, and each of the recesses includes a plurality of organic EL elements arranged at predetermined intervals in the first direction, wherein the plurality of recesses Has a plurality of first recesses whose width in the second direction becomes narrower from one end in the first direction to the other end, and the width in the second direction is the first The display device includes a plurality of second recesses that become wider from one end of the direction toward the other end.

  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 predetermined intervals in the first direction X and the second direction Y perpendicular to the first direction X. Placed in. In the present embodiment, the organic EL elements 22 are arranged at equal intervals in the first direction X and are arranged at equal intervals in the second direction Y.

  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. 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 11 as necessary. 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). 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 the positions where the 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 17 extending in the first direction X is provided on the insulating film 15. Each partition member 17 is disposed between organic EL elements adjacent 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. That is, a plurality of recesses 18 are defined by a pair of the partition members 17 facing the second direction Y perpendicular to the first direction X, and a predetermined interval is provided in each recess 18 in the first direction. A plurality of organic EL elements 22 are arranged. 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, an electron blocking layer, and the like are provided as a functional layer between the anode and the light emitting layer. Between the light emitting layer and the cathode, a hole blocking layer, an electron transport layer, an electron injection layer, and the like are provided as functional layers.

  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 17 adjacent to each other in the second direction Y in a plan view, and are arranged at predetermined intervals in the first direction X between the partition members 17.

  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 arranged extending in the first direction X in a region sandwiched between the partition members 17. That is, the hole injection layer 13 is formed in a band shape in the recess 18 defined by the partition wall member 17 adjacent in the second direction Y, and is continuous 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 17. That is, the light emitting layer 14 is formed in a strip shape in the recess 18 defined by the partition member 17 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 can be 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 plan view showing the arrangement of the partition members 17 of the light emitting device 21 in an exaggerated manner. As shown in FIG. 3, the plurality of recesses 18 defined by the partition wall member 17 has a width that decreases in the width in the second direction Y as it approaches the other end from one end in the first direction. The first concave portion and a plurality of second concave portions whose width in the second direction becomes wider from one end portion in the first direction toward the other end portion. In the following, “the width of the recess 18 in the second direction Y” may be simply referred to as “the width of the recess 18”.

There are the following two types of arrangement of the first recess and the second recess.
(1) The first recesses and the second recesses are alternately arranged in the second direction (see FIG. 3).
(2) An array of concave portions arranged in the order of the first concave portion, the first concave portion, the second concave portion, and the second concave portion in the second direction is repeatedly arranged in the second direction (FIG. 7). reference).

  For example, when the functional layer common to all the organic EL elements is formed uniformly, the configuration (1) is preferable. For example, when the light emitting layer of a monochrome display device is formed uniformly, the configuration (1) is preferable. Furthermore, the configuration of (1) is preferable when different types of odd types (for example, red ink, green ink, and blue ink described later) are applied separately.

  In addition, when even types (for example, red ink, green ink, blue ink, and white ink containing a material that emits white light) are separately applied, when the coating film of the ink is particularly uniformly formed, (2) A configuration is preferred.

  The recess 18 composed of the first recess and the second recess is defined by the arrangement of the partition member 17 as shown in FIG. Specifically, the partition wall member 17 extending in a direction slightly tilted clockwise with the straight line extending in the first direction X as a fulcrum, and the straight line extending in the first direction X are By alternately disposing the partition wall members 17 extending in the direction slightly inclined counterclockwise with the center as a fulcrum, the first recesses and the first recesses of the arrangement (1) described above are arranged. 2 recesses are formed.

  The taper angle of the width of the concave portion (in this embodiment shown in FIG. 3, the crossing angle when the pair of partition wall members 17 facing the second direction Y are extended and virtually crossed) is 0.00001 °. ˜0.1 °, preferably 0.0001 ° to 0.01 °.

  In the embodiment shown in FIG. 3, the first recess and the second recess are configured by slightly changing the extending direction of the partition member 17, but for example, as shown in FIG. 4, the partition member 17 The first recess and the second recess may be configured by increasing the second width of the second toward the one or the other in the first direction. 4 is a plan view exaggeratingly showing the arrangement of the partition member 17 of the light emitting device 21. The partition member 17 is hatched.

  When a plurality of recesses composed of a plurality of first recesses and a plurality of second recesses are formed in this way, as described later, when supplying ink, the width of the recesses is narrowed from one of the wide recesses. When ink is continuously supplied toward the other side, the thickness of the coating film can be made substantially uniform.

<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 includes a support substrate, a partition wall formed of a plurality of partition wall members extending in the first direction on the support substrate, and a second direction perpendicular to the first direction. A plurality of recesses are defined by the pair of partition members facing each other, and a plurality of organic EL elements arranged at predetermined intervals in the first direction in the respective recesses. And the width of the concave portion in the second direction becomes narrower from one end portion in the first direction toward the other end portion, and the width in the second direction of the concave portion. A partition wall having a shape forming a plurality of second recesses that become wider from one end portion in the first direction toward the other end portion, and pixel electrodes of the plurality of organic EL elements provided thereon A step of preparing the supported substrate and a nozzle plug between the partition members. And a step of forming a predetermined functional layer of the organic EL element by supplying a predetermined ink by a printing method and solidifying the ink, and a step of forming an upper electrode on the functional layer, The present invention relates to a method for manufacturing a display device, in which ink is continuously supplied from one wide concave portion to the other narrow concave portion.

(Process for preparing support substrate)
In this step, the width of the concave portion in the second direction becomes narrower from one end portion of the first direction toward the other end portion, and the width of the concave portion in the second direction. However, a partition wall having a shape forming a plurality of second recesses that become wider from one end portion in the first direction toward the other end portion, and pixel electrodes of the plurality of organic EL elements are formed thereon A provided support substrate is prepared. In this embodiment, a support substrate provided with an insulating film 15 is prepared. That is, a support substrate 11 is prepared, on which the insulating film 15 disposed so that the pixel electrode 12 is exposed from the opening is 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. In addition, by forming the pixel electrode 12, the insulating film 15, and the partition member 17 in this step as follows, the support substrate 11 on which the pixel electrode 12, the insulating film 15, and the partition member 17 are provided is prepared. However, the support substrate 11 may be prepared by obtaining from the market a support substrate 11 on which the pixel electrode 12, the insulating film 15, and the partition wall member 17 are 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.

Next, a lattice-like insulating film 15 is formed on the support substrate 11. 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 .

  When 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 17 are formed on the insulating film 15, and the partition walls 17 are provided. In this step, the width of the concave portion in the second direction becomes narrower from one end portion in the first direction toward the other end portion, and the width in the second direction of the concave portion. However, a partition wall having a shape that forms a plurality of second concave portions that become wider from one end portion in the first direction toward the other end portion is formed. For example, a partition wall having the shape shown in FIG. 3 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 17 in the second direction Y is about 5 μm to 50 μm, the height L2 of the partition member 17 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. As described above, in particular, as shown in FIG. 3, (1) when the first recesses and the second recesses are alternately arranged in the second direction, a function common to all organic EL elements. The layer is preferably formed by a nozzle printing method. Examples of ink supply methods other than nozzle printing include spin coating, slit coating, ink jet printing, letterpress printing, and intaglio printing.

  In this embodiment, the hole injection layer 13 common to all organic EL elements is formed. Therefore, it is preferable to supply an ink containing a material for forming the hole injection layer 13 (hereinafter, also referred to as a hole injection layer ink) by a nozzle printing method.

  Hereinafter, this process will be described with reference to FIG. FIG. 5 is a diagram schematically showing the operation when ink is applied by the nozzle printing method. 5, the arrangement of the partition members 17 of the light emitting device 21 is exaggerated as in FIG.

  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, while the nozzle 4 is reciprocated in the first direction X while the liquid columnar hole injection layer ink is being ejected from the nozzle 4 disposed above the support substrate 11, the reciprocation of the nozzle 4 is reversed. 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, the ink for the hole injection layer can be supplied to all the rows by moving the support substrate by one row in the second direction Y when the nozzle 4 is turned back and forth.

  In the present embodiment, when supplying ink, in the first direction X, ink is continuously supplied from one wide recess to the other narrow recess. Referring to FIG. 5, when the width of the recess is wider on the right side than on the left side, the nozzle 4 moves from the right side to the left side in the row. Conversely, when the width of the recess is wider on the left side than on the right side, the nozzle 4 moves from the left side to the right side in the row.

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 4, so that all the partition wall members 17 (recesses 18 are formed). ) Can be supplied with an ink for a hole injection layer.
(1) A step of moving the nozzle 4 from one end to the other end in the first direction X.
(2) A step of moving the support substrate 11 in one direction in the second direction Y by one line.
(3) A step of moving the nozzle 4 from the other end in the first direction X to one end.
(4) A step of moving the support substrate by one line in one of the second directions Y.

  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 supplying the ink, in the first direction X, the ink is continuously supplied from one wide side of the concave portion to the other narrow side of the concave portion to thereby obtain a substantially uniform film thickness. The functional layer (in this embodiment, a hole injection layer) can be formed.

(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. As in this embodiment, when different types of ink (red ink, green ink, blue ink) are separately applied, the partition 20 having the above-described configuration (1) as shown in FIG. Similar to the method of forming the hole injection layer, it is preferable to supply ink by the nozzle printing method.

More specifically, the following steps (1) to (4) are repeated in this order while the liquid columnar red ink is ejected from the nozzle 4, so that two rows are spaced in the second direction Y. Red ink can be supplied between the partition members 17 (recesses 18) (see FIG. 6).
(1) A step of moving the nozzle 4 from one end to the other end in the first direction X.
(2) A step of moving the support substrate 11 in one direction in the second direction Y by three rows.
(3) A step of moving the nozzle 4 from the other end in the first direction X to one end.
(4) A step of moving the support substrate in one direction in the second direction Y by three rows.

  By supplying green ink and blue ink respectively in the same manner as the red ink described above, green ink and blue ink are supplied between the partition members 17 (recesses 18) with an interval of two lines in the second direction Y, respectively. can do.

  As described above, when the odd-type ink is separately applied by the nozzle printing method, in the first direction X, the ink is continuously supplied from one wide width of the concave portion to the other narrow width of the concave portion, A functional layer having a substantially uniform thickness (in this embodiment, a light emitting layer) can be formed.

  In addition, the luminescent material used for red ink, green ink, and blue ink is mentioned 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.

  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, when supplying ink, in the first direction X, ink is continuously supplied from one wide concave portion to the other narrow concave portion. Thus, a functional layer having a substantially uniform film thickness (in this embodiment, a hole injection layer and a light emitting layer) can be formed. By forming a functional layer having a substantially uniform film thickness (in this embodiment, a hole injection layer and a light emitting layer) as described above, variation in the light emission characteristics of each organic EL element can be suppressed, and streaks are generated for each row. Observation can be prevented, and display quality as a display device can be improved.

  In the above description, (1) the mode in which the first recesses and the second recesses are alternately arranged in the second direction (see FIG. 3) has been described. An array of recesses arranged in the order of the first recess, the first recess, the second recess, and the second recess may be repeatedly arranged in the second direction (see FIG. 7).

  In such an arrangement, when the even-numbered types (for example, red ink, green ink, blue ink, and white ink containing a material that emits white light) are separately applied, the concave portion is recessed from one of the wide concave portions. Ink can be continuously supplied toward the other narrow side. Thereby, the film thickness of various light emitting layers can be made uniform.

<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, and ytterbium. 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, polyvinylcarbazole 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.

4 nozzle 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 (4)

A support substrate;
A partition wall made of a plurality of partition wall members extending in the first direction on the support substrate;
A plurality of recesses are defined by a pair of partition members facing a second direction perpendicular to the first direction, and a plurality of recesses are arranged at predetermined intervals in the first direction in the respective recesses. A display device comprising an organic EL element,
The plurality of recesses have a plurality of first recesses whose width in the second direction becomes narrower from one end in the first direction toward the other end, and a width in the second direction. A display device comprising a plurality of second recesses that become wider from one end in the first direction toward the other end.   The display device according to claim 1, wherein the first recesses and the second recesses are alternately arranged in the second direction.   The arrangement of the concave portions arranged in the order of the first concave portion, the first concave portion, the second concave portion, and the second concave portion in the second direction is repeatedly arranged in the second direction. Display device. A plurality of partition walls are formed by a support substrate, a partition wall formed of a plurality of partition wall members extending in a first direction on the support substrate, and a pair of partition wall members opposed to a second direction perpendicular to the first direction. And a plurality of organic EL elements arranged at predetermined intervals in the first direction in each of the recesses,
The width of the concave portion in the second direction becomes narrower from one end portion in the first direction toward the other end portion, and the width in the second direction of the concave portion is the first width. A partition wall having a shape forming a plurality of second concave portions that become wider from one end portion in one direction toward the other end portion, and pixel electrodes of the plurality of organic EL elements are provided thereon. A step of preparing a support substrate, a step of supplying a predetermined ink between the partition members by a nozzle printing method, and solidifying the ink, thereby forming a predetermined functional layer of the organic EL element;
Forming an upper electrode on the functional layer,
A method for manufacturing a display device, wherein when supplying the ink, in the first direction, the ink is continuously supplied from one wide concave portion to the other narrow concave portion.

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