JP2011076760A - Organic el device and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic EL device capable of preventing moisture, air, or the like, in the atmosphere from entering an adhesive portion between a substrate having a plurality of light emission pixel regions and columnar barrier ribs formed on one surface and a sealing base material, and to provide a method of manufacturing the organic EL device. <P>SOLUTION: When the organic EL device is manufactured by sticking an organic EL element substrate 10 and a sealing substrate 21 together by an adhesive, a plurality of projections 15 are arranged and installed on intersection portions of the columnar ribs 14 to demarcate a first electrode 13 of the organic EL substrate 10; and the organic EL element substrate 10 and the sealing substrate 21 are stuck together, while the tips of these projections 15 are abutted against the sealing substrate 21. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an organic EL device using an organic electroluminescence (hereinafter referred to as “organic EL”) phenomenon and a method for manufacturing the same.

  A thin film transistor (TFT) is provided on a substrate, electrodes (anode, cathode) are provided so as to be connected to the TFT, and an organic light emitting layer exhibiting at least an EL emission phenomenon is laminated between the anode and the cathode. In an organic EL device including a plurality of organic EL elements, insulative partition walls are formed in a lattice pattern on one surface of the substrate so as to surround the light emitting pixel regions of these organic EL elements. Furthermore, for the purpose of increasing luminous efficiency, a hole transport layer and a hole injection layer are disposed between the anode and the organic light emitting layer, and an electron transport layer and an electron injection layer are disposed between the organic light emitting layer and the cathode. There is also a case. These laminated structures are called organic light emitting medium layers.

  However, since such a cathode and an electron injection layer are highly active, they easily react with moisture in the atmosphere and are easily altered. Due to such alteration, the electron injection effect is impaired, and a non-light emitting portion called a dark spot is generated in the pixel. Therefore, conventionally, there is a structure in which a substrate on which an organic EL element is formed (hereinafter referred to as “organic EL element substrate”) and a sealing substrate made of glass or the like are bonded with a resin or the like so as to cover the organic EL element. Are known.

  When sealing is performed in a state where a resin or the like is applied in this way, it is necessary to precisely control the gap (interval) between the organic EL element substrate and the sealing base material, and to make the height of the entire substrate constant. . When this height is not uniform, alteration occurs due to moisture in the atmosphere mixed into the bonded portion between the organic EL element substrate and the sealing substrate. This alteration leads to deterioration of the organic EL device. Therefore, it is necessary to prevent alteration by managing the gap between the substrates. As a simple method for managing such a gap, a method of forming a spacer (gap material) on at least one of substrates to be bonded is known (see Patent Document 1).

JP 2005-294057 A

  However, as in the technique disclosed in Patent Document 1, a color filter substrate and an organic EL element as a sealing substrate are formed by forming a spacer on a substrate having a color filter layer (hereinafter referred to as “color filter substrate”). When the substrate is bonded, an overlap phenomenon or a horn step due to the color filter layer running on the black matrix layer occurs, making it difficult to precisely adjust the gap between the organic EL element substrate and the color filter substrate. There was a problem. Therefore, in the substrate in which the spacer is provided on the color filter, the height in the substrate cannot be made uniform due to these effects, and there is a problem that the cell gap with the counter substrate varies.

Such a phenomenon can be seen even in the case of an organic EL device. When the substrate on which the spacer is formed on the color filter and the substrate on which the organic EL element is formed are bonded using a resin or the like, the substrate and the substrate having the spacer formed on the color filter are There was a problem that the organic EL element substrate could not be bonded uniformly. Due to such a phenomenon, moisture and oxygen in the atmosphere are mixed in the organic EL device. Since the cathode and the electron injection layer on the organic EL element substrate are composed of a highly active material, the deterioration due to the moisture and oxygen occurs. Therefore, an organic EL device that forms spacers on the organic EL element substrate and enables uniform bonding with a color filter is required.
Further, when a protrusion is formed on the organic EL element substrate, there is a problem that when the organic light emitting medium layer is printed using the relief printing method, the protrusion comes into contact with the relief printing plate and printing failure occurs. It was. Therefore, it is necessary to arrange the protrusions at a position that does not contact the printing plate.

The letterpress printing method is one of the methods in the printing method. Here, the printing plate used by the relief printing method has a plurality of stripe-shaped convex portions, and an organic light emitting material ink is applied to the convex portions, and the ink is applied onto the substrate. When this method is used to form an organic light emitting medium layer, it is possible to form a finer pattern than when using other methods such as vacuum deposition, and to form an organic light emitting medium layer that is a uniform thin film. To do.
The present invention has been made in view of the above-described problems, and moisture, air, etc. in the atmosphere are present at the bonding portion between the substrate having the plurality of light emitting pixel regions and the grid-like partition formed on one surface and the sealing base material. An object of the present invention is to provide an organic EL device that can be prevented from entering and a method for manufacturing the same.

  In order to solve the above-mentioned problems, an invention according to claim 1 of the present invention surrounds a plurality of light-emitting pixel regions formed by stacking a first electrode, an organic light-emitting medium layer, and a second electrode, and the light-emitting pixel regions. A substrate having a lattice-shaped partition wall on one surface; and a sealing substrate bonded to the substrate through the light-emitting pixel region and the lattice-shaped partition wall, wherein the lattice-shaped partition wall is parallel to each other. A method of manufacturing an organic EL device including one partition line and a plurality of second partition lines orthogonal to the first partition line, wherein a plurality of protrusions are disposed only on the first partition line. Thereafter, at least one of a plurality of layers forming the organic light emitting medium layer is patterned along the first partition line by letterpress printing, and then the second electrode is formed on the organic light emitting medium layer After that, the tip of the projection is sealed with the seal. Characterized in that being in contact with the base material bonding the said substrate and said sealing substrate.

  According to a second aspect of the present invention, in the method for manufacturing an organic EL device according to the first aspect, the plurality of protrusions are disposed on an intersection of the first partition line and the second partition line. Thereafter, at least one layer of the plurality of layers forming the organic light emitting medium layer is patterned along the first barrier rib line or the second barrier rib line by a relief printing method, and then formed on the organic light emitting medium layer. After the second electrode is formed, the substrate and the sealing base material are bonded together in a state where the tip of the protrusion is in contact with the sealing base material.

  According to a third aspect of the present invention, in the method for manufacturing an organic EL device according to the first or second aspect, at least one of the plurality of layers forming the organic light emitting medium layer is patterned by the relief printing method. At the time of forming, at least one layer among the plurality of layers forming the organic light emitting medium layer is patterned using a relief printing plate having a plurality of convex portions formed on the surface in a stripe shape.

According to a fourth aspect of the present invention, in the method for manufacturing an organic EL device according to the third aspect, a relief printing plate is used in which the width of the convex portion in the short side direction is smaller than the length of one side of the organic light emitting medium layer. Then, at least one of the plurality of layers forming the organic light emitting medium layer is patterned.
The invention according to claim 5 of the present invention is the method of manufacturing an organic EL device according to claim 3 or 4, wherein the width of the convex portion in the short side direction is equal to two adjacent protrusions among the plurality of protrusions. It is characterized in that at least one layer among the plurality of layers forming the organic light emitting medium layer is patterned using a relief printing plate smaller than the interval.

The invention according to claim 6 of the present invention is the method for manufacturing an organic EL device according to any one of claims 3 to 5, wherein a relief printing plate in which the height of the projection is lower than the height of the projection is used. Then, at least one of the plurality of layers forming the organic light emitting medium layer is patterned.
According to a seventh aspect of the present invention, a plurality of light-emitting pixel regions formed by laminating a first electrode, an organic light-emitting medium layer, and a second electrode and a grid-like partition wall surrounding the light-emitting pixel region are provided on one surface. A plurality of first partition lines that are parallel to each other, and a first substrate line that includes the substrate, the light emitting pixel region, and a sealing substrate that is bonded via the lattice partition. An organic EL device formed by a plurality of second partition lines orthogonal to the partition lines, wherein a plurality of protrusions defining a distance between the substrate and the sealing base is a first partition of the lattice-shaped partition It is arranged on a line.

According to an eighth aspect of the present invention, in the organic EL device according to the seventh aspect, the plurality of protrusions are arranged on the intersection of the first partition line and the second partition line of the grid-shaped partition. It is characterized by.
The invention according to claim 9 of the present invention is the organic EL device according to claim 7 or 8, wherein the sealing substrate colorizes the light from the light emitting pixel region, and the color filter layer. And a black matrix layer partitioned in a lattice pattern.
According to a tenth aspect of the present invention, in the organic EL device according to the ninth aspect, the protrusion is formed at a position facing the black matrix layer.

  According to the first aspect of the present invention, the distance (gap) between the substrate and the sealing base material is constant over the entire surface of the substrate by the plurality of protrusions disposed on the first partition line of the lattice partition. Therefore, it is possible to prevent moisture and air in the atmosphere from entering the bonded portion between the substrate and the sealing base material. Therefore, the light emitting pixel region is altered by moisture that has entered the bonding portion between the substrate and the sealing base material, or bubbles are generated in the light emitting pixel region due to air that has entered the bonding portion between the substrate and the sealing base material. Can be suppressed. In addition, for example, when patterning the organic light emitting layer by a relief printing method, the organic light emitting layer is patterned along the first partition line to prevent the convex portions of the relief printing plate from interfering with the protrusions. Can do.

According to the invention of claim 2 of the present invention, the convex part of the relief printing plate may interfere with the projections even if the printing direction by relief printing is selected to be either the horizontal direction or the longitudinal direction of the grid-like partition wall. Therefore, the organic light emitting medium layer can be formed from either the horizontal direction or the vertical direction of the lattice-shaped partition walls.
According to the invention of claim 3 of the present invention, it is possible to form the organic light emitting medium layer on the first electrode only by aligning the convex portion of the relief printing plate with the region surrounded by the grid-like partition walls. The organic light emitting medium layer can be precisely formed on the first electrode.

According to the invention according to claim 4 of the present invention, it is possible to prevent the convex portion of the relief printing plate from interfering with the side surface of the grid-like partition wall, whereby the organic light emitting medium layer is formed on the first electrode. It can be formed precisely.
According to the invention of claim 5 of the present invention, it is possible to prevent the convex portion of the relief printing plate from interfering with the protrusions, thereby accurately forming the organic light emitting medium layer on the first electrode. can do.

According to the invention of claim 6 of the present invention, it is possible to prevent the convex portion of the relief printing plate from interfering with the protrusions, thereby accurately forming the organic light emitting medium layer on the first electrode. can do.
According to the invention of claim 7 of the present invention, the distance (gap) between the substrate and the sealing substrate is constant over the entire surface of the substrate by the plurality of protrusions disposed on the first partition line of the lattice partition. Therefore, it is possible to prevent moisture and air in the atmosphere from entering the bonded portion between the substrate and the sealing base material. Therefore, the light emitting pixel region is altered by moisture that has entered the bonding portion between the substrate and the sealing base material, or bubbles are generated in the light emitting pixel region due to air that has entered the bonding portion between the substrate and the sealing base material. Can be suppressed.

According to the inventions according to claims 8 and 9 of the present invention, the convex portion of the relief printing plate interferes with the projections even if the printing direction by relief printing is selected to be either the horizontal direction or the longitudinal direction of the grid-like partition wall. Therefore, the organic light emitting medium layer can be formed from either the horizontal direction or the vertical direction of the lattice-shaped partition walls.
According to the invention of claim 10 of the present invention, the substrate and the sealing substrate are bonded together in a state in which the plurality of protrusions disposed on the lattice-shaped partition walls are in contact with the intersections of the black matrix layers. Can do.

It is sectional drawing which shows typically the structure of the top emission type organic EL apparatus which concerns on one Embodiment of this invention. It is a figure which shows typically the protrusion arrange | positioned on the grid | lattice-like partition of the top emission type organic EL device concerning one embodiment of the present invention. It is sectional drawing which shows typically the convex part and light emission pixel area | region of a relief printing plate used when forming the organic light emitting medium layer of an organic EL apparatus.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the drawings referred to in the following description are for explaining the configuration of the present invention, and the size, thickness, dimensions, and the like of each part shown in the drawings are different from the actual ones. Further, the present invention is not limited to these.
1 to 3 are diagrams for explaining an embodiment of the present invention, and FIG. 1A schematically illustrates the structure of an organic EL element substrate of a top emission type organic EL device according to an embodiment of the present invention. FIG. 1B is a sectional view schematically showing the structure of the color filter substrate of the top emission type organic EL device according to one embodiment of the present invention. FIG. 1C is a cross-sectional view schematically showing the structure of the top emission type organic EL device according to one embodiment of the present invention. The top emission type organic EL device according to one embodiment of the present invention is shown in FIG. The organic EL element substrate 10 having the structure shown in FIG. 1A and the color filter substrate 20 having the structure shown in FIG.

Here, the organic EL element substrate 10 includes a substrate 11, a planarizing film 12, a first electrode 13, a lattice partition 14, a protrusion 15, an organic light emitting medium layer 16, a second electrode 17, a protective film 18, and a thin film transistor layer (see FIG. The color filter substrate 20 includes a sealing substrate 21, a color filter layer 22, and a black matrix layer 23.
Hereinafter, each part which comprises the organic EL element substrate 10 is demonstrated.
The material of the substrate 11 may be any material having an insulating property or a substrate having an insulating thin film formed on the surface thereof, and the color of the substrate is not particularly limited. A thin film transistor (TFT) is formed on the surface of the substrate 11 for the purpose of controlling power supply to a first electrode 13 described later. This thin film transistor can be produced by a known technique. For example, a semiconductor film having a source region, a drain region, and a channel region and made of polycrystalline silicon, amorphous silicon, or the like is formed on the substrate 11, and a gate electrode is formed on a transparent gate insulating film that covers the semiconductor film. Thus, the TFT can be formed on the substrate 11. In this case, the gate electrode is preferably formed of Al, Mo, Ti, Ta, or the like and formed at a position corresponding to the channel region of the semiconductor film.

  The flattening film 12 is formed between the TFT on the substrate 11 and the first electrode 13 for the purpose of absorbing unevenness on the substrate surface caused by forming the TFT on the substrate 11 and flattening the substrate surface. Is. Therefore, it is necessary to use a material that has insulating properties and excellent flatness as the material of the planarizing film 12, and examples thereof include polyimide-based and acrylic-based resin materials.

The first electrode 13 is formed on the surface of the planarizing film 12, and is electrically connected to the gate electrode of the TFT through a metal wiring in a through hole formed in the planarizing film 12 in order to make the TFT function. Connected to. When connected to the source electrode of the TFT, it functions as an anode, and when connected to the drain electrode of the TFT, it functions as a cathode.
The material of the first electrode 13 is not particularly limited as long as it is a conductive material, but is a conductive material such as a material having a high work function (for example, tin-doped indium oxide (ITO), zinc-doped indium oxide (IZO)). It is preferable to use (metal oxide). Further, the thickness of the first electrode 13 is not particularly limited, but it is preferable to form the first electrode 13 on the planarizing film 12 with a thickness of 0.02 μm or more and 0.5 μm or less because the thickness becomes thinner than the thickness of the grid-like partition wall 14.

  When the first electrode 13 is formed of a conductive metal oxide such as ITO or IZO, a highly reflective metal electrode is interposed between the first electrode 13 and the planarizing film 12 in order to obtain efficient light emission. It may be formed. Since such a metal electrode has a lower resistivity than a conductive metal oxide, the metal electrode functions as an auxiliary electrode, and at the same time, it is possible to effectively use light by reflecting light toward the counter substrate. The metal electrode may be a metal having high reflectivity, and examples thereof include high reflectivity metals such as Ag, Al, Mo, and Ta.

  The grid-shaped partition wall 14 is for partitioning the light-emitting pixel region composed of the first electrode 13, the organic light emitting medium layer 16, and the second electrode 17 in a grid pattern. The planarizing film 12 covers the end of the first electrode 13. It is formed in a lattice shape on top. The material of the grid-shaped partition 14 is not particularly limited as long as it has insulating properties, and specific examples include materials such as polyimide, acrylic resin, and novolac resin.

The grid-shaped partition 14 is formed of a plurality of first partition lines 141 (see FIG. 2) parallel to each other and a plurality of second partition lines 142 (see FIG. 2) orthogonal to the first partition lines 141. ing.
When the lattice-like partition 14 is formed on the surface of the planarizing film 12, the height of the lattice-like partition 14 may be set according to the thickness of the entire organic EL element, but the height of the lattice-like partition 14 is less than 0.1 μm. In this case, the color of each emission color is insufficient when the organic light emitting medium layer 16 is formed, or the grid-like partition wall 14 cannot cover the end portion of the first electrode 13 and is short-circuited. When the thickness exceeds 10 μm, the formation of the organic light-emitting medium layer 16 is hindered. Therefore, the height of the grid-like partition wall 14 is 0.1 μm or more and 10 μm or less, preferably 0.5 μm or more and 2 μm or less. It is preferable.

The protrusions 15 maintain a constant gap between the substrate 11 on which the organic EL element is formed and the sealing substrate 21 on which the color filter layer 22 and the like are formed, thereby making the height of the entire organic EL device constant. For this purpose, the tip is projected from the surface of the protective film 18 and is provided on the lattice-like partition 14.
FIG. 2 is a diagram schematically showing the protrusions disposed on the grid-like partition walls. As shown in FIG. 2, the projections 15 are preferably formed on the first partition line 141 of the grid-like partition walls 14. It is disposed on the intersection 143 between the partition line 141 and the second partition line 142.

A known technique can be used as a method for forming the protrusion 15, and examples thereof include a photolithography method and a printing method. In addition, there is a method in which a roll coating method, a spin coating method, or the like is used as a pattern forming method and combined with a photolithography method.
As a material of the protrusion 15, it is desirable that the protrusion 15 is a material that is not deformed or deteriorated due to stress from the sealing substrate 21, and may be a material that satisfies this condition. Examples include thermosetting resins such as epoxy monomers and epoxy oligomers, thermoplastic resins such as polyester resins and acrylic resins, and photocurable resins such as photocurable epoxy resins. May be used alone or in combination.

However, the protrusion 15 makes the height of the organic EL element substrate 10 constant, and the tip of the protrusion 15 is in contact with the sealing substrate 21 and the adhesive layer 30 to achieve uniform bonding. Therefore, the protrusion 15 is preferably made of a material that can be easily processed. As a material that satisfies such conditions, an acrylic resin that can be easily processed after curing is preferable as the material of the protrusion 15.
When the protrusion 15 described above is disposed on the first partition line 141 of the lattice-shaped partition wall 14, preferably on the intersection 143 between the first partition line 141 and the second partition line 142, the height of the protrusion 15 is increased. It is preferable that the height is 0.5 μm or more, and preferably the height that is the sum of the heights of the grid-like partition walls 14 is 10 μm or less. This is because when the height of the protrusion 15 is less than 0.5 μm, the protrusion 15 cannot withstand the stress generated from the sealing substrate 21 after bonding, and is damaged. This is because the cell gap cannot be made uniform, leading to deterioration due to the mixing of moisture and oxygen in the atmosphere.

  The organic light emitting medium layer 16 is formed between the first electrode 13 and the second electrode 17 and includes at least an organic light emitting layer, and for the purpose of light emission with low voltage and high efficiency, and a hole injection layer and hole transport A structure in which a layer, an electron transport layer, and an electron injection layer are appropriately selected and each layer is laminated. Each layer of the organic light emitting medium layer 16 may have a single layer structure or a laminated structure. Moreover, although the luminescent color of an organic light emitting layer is not ask | required, it is preferable that they are three colors of red, green, and blue desirably.

Examples of the hole transport material used for the hole transport layer of the organic light emitting medium layer 16 include copper phthalocyanine and derivatives thereof, 1,1-bis (4-di-p-triaminophenyl) cyclohexane, N, N′-diphenyl-N. , N′-bis (3-methylphenyl) -1,1′-biphenyl-4,4′-diamine and other low molecular weight materials such as aromatic amines, polyaniline derivatives, polythiophene derivatives, polyvinylcarbazole derivatives, poly (3,4 -Ethylenedioxythiophene) (hereinafter PEDOT) or a polymer material such as a mixture of PEDOT and polystyrene sulfonic acid (hereinafter PSS) (PEDOT / PSS), polythiophene oligomer material, CU ₂ O, Mn ₂ O ₃ , NiO, Ag ₂ O, MoO ₂ , ZnO, TiO, Ta ₂ O ₅ . Examples of the inorganic material compound include MoO ₃ , WO ₃ , and MoO ₃ . As a method for forming a hole transport layer from these materials, a known technique can be used. For example, a positive deposition method obtained by dissolving and dispersing a hole transport material in a solvent by using a vacuum deposition method, a sputtering method, or the like. The method of apply | coating hole transport material ink etc. are mentioned. Moreover, a well-known technique can be used also for the method of apply | coating hole transport material ink, for example, a spin coat method, the photolithography method, the inkjet method, the printing method etc. are mentioned.

  Further, when the hole transport material is a polymer material, an interlayer layer may be formed in the organic light emitting medium layer 16 for the purpose of improving the hole transport property. This interlayer is preferably formed between the hole transport layer and the organic light emitting layer. Examples of the material for such an interlayer layer include polyarylene-based, polyarylene vinylene-based, polyfluorene-based, and other high-molecular materials, and materials mixed with low-molecular substances such as aromatic amines.

  Examples of the organic light emitting material used for the organic light emitting layer of the organic light emitting medium layer 16 include a coumarin type, a perylene type, a pyran type, an anthrone type, a porphyrene type, a quinacdrine type, an N, N′-dialkyl-substituted quinacdrine type, a naphthalimide type, Low molecular weight light emitting dyes such as iridium complex and platinum complex are dissolved or polymerized in polymer materials such as polystyrene, polymethyl methacrylate, polyvinyl carbazole, polyarylene, polyarylene vinylene, poly Examples include fluorene-based polymer materials.

  When an organic light emitting layer is formed using these organic light emitting materials, a method of applying an organic light emitting ink that has been made into an ink by dissolving and dispersing the organic light emitting material in a solvent can be used. Examples of the solvent to be used include toluene, xylene, anisole, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone and the like, or a mixed solvent thereof. In particular, aromatic organic solvents such as toluene, xylene, and anisole are preferable.

In addition, a known technique can be used for applying the organic light-emitting material in an ink, and examples thereof include a spin coating method, a photolithography method, an inkjet method, and a printing method.
As an electron transport material used for the electron transport layer of the organic light emitting medium layer 16, 2- (4-biphenylyl) -5- (4-t-butylphenyl) -1,3,4-oxadiazole, 2, 5-bis (1-naphthyl) -1,3,4-oxadiazole and the like. These electron transport materials may be doped with a small amount of an alkali metal having a low work function such as sodium, barium, or lithium.

Next, a method for forming the organic light emitting medium layer 16 will be described. In the following description, the case where the present invention is applied to the formation of an organic light emitting layer will be described as an example. However, the present invention can also be applied to a hole transport layer, an electron transport layer, and the like.
When forming the organic light emitting layer of the organic light emitting medium layer 16, in this embodiment, the organic light emitting layer is formed using a relief printing method. The letterpress printing method is a printing method using a printing plate (hereinafter referred to as “letterplate”) in which a plurality of convex portions are formed of a synthetic resin material or the like on the substrate surface of the printing plate. By using this method, a fine pattern can be formed on the substrate. In particular, the method using the relief printing method makes it possible to form a fine pattern and to form a layer having excellent film thickness uniformity, and to use a polymer material as the organic light emitting material. Therefore, it is possible to form a high-definition and highly flat organic light-emitting layer in the light-emitting pixel region surrounded by the grid-like partition walls 14. In particular, it is suitable when the organic light emitting layer is separately applied to a plurality of light emission colors.

  When patterning an organic light-emitting layer or the like using a relief printing method, it is only necessary to strictly align in only one direction by using a relief plate in which the convex portions on the surface of the relief substrate are formed in stripes. There are advantages. That is, the organic light emitting layer can be patterned by the relief printing method simply by aligning the convex portion of the relief plate with the light emitting pixel region surrounded by the grid-like partition wall 14, so that the organic light emitting layer free from printing misalignment is the first. A pattern can be formed on the electrode 13.

  The base material of the relief plate may be a material having mechanical strength against printing and high resistance to an organic solvent added to the organic light emitting material. For example, metal materials such as iron, copper, and aluminum, iron and nickel, etc. The alloy material of these is mentioned. The convex part on the surface of the relief base material can be formed by a known technique, and the material is not limited. Preferably, convex portions such as synthetic resins such as polyethylene, polystyrene, polybutadiene, polyvinyl chloride, polyamide, polyethylene terephthalate, and polyvirini alcohol, metal materials such as iron, copper, and aluminum, and monolayers and laminates thereof. Can be used as a material.

  When an organic light emitting layer is formed using a relief plate having a plurality of protrusions formed in a stripe shape on the surface of the substrate, the protrusions 15 are arranged on the grid-like partition walls 14 in an arrangement as shown in FIG. 2B, for example. In the case of being provided, the organic light-emitting layer is formed by relief printing along the direction indicated by the arrow X1 in FIG. 2B (direction parallel to the first partition wall line 141) in order to avoid interference with the protrusion 15. Need to be formed.

  On the other hand, as shown in FIG. 2A, when the protrusion 15 is disposed on the intersection 143 between the first partition line 141 and the second partition line 142 of the grid-shaped partition 14, Even if the printing direction by the letterpress is selected from either the horizontal direction (direction indicated by the arrow X1 in FIG. 2A) or the vertical direction (direction indicated by the arrow Y1 in FIG. 2A) of the grid-like partition wall 14, Since the convex portion and the projection 15 do not interfere with each other, the organic light emitting layer can be formed from either the horizontal direction or the vertical direction of the lattice-like partition 14.

  Therefore, when the protrusions 15 are arranged on the grid-like partition wall 14 in the arrangement shown in FIG. 2A, the organic light emitting layer is formed by relief printing along the direction indicated by the arrow X1 in FIG. After that, the next layer formed on the organic light emitting layer (for example, the electron transport layer when the first electrode 13 is an anode and the hole transport layer when the first electrode 13 is a cathode) is formed on the organic light emitting layer. It can be formed by letterpress printing along a direction perpendicular to the printing direction (direction indicated by arrow Y1 in FIG. 2A).

FIG. 3 is a cross-sectional view schematically showing convex portions and light emitting pixel regions of a printing plate used when forming an organic light emitting medium layer. 3 shows three grid-like partition walls 14 and light-emitting pixel regions. However, in an actual organic EL device, the grid-like partition walls 14 and light-emitting pixel regions as shown in FIG. A plurality are formed.
As shown in FIG. 3, the length of one pixel of the light emitting pixel region is a, the length of the stripe-shaped convex portion 31 of the relief printing plate in the short side direction is b, and a plurality of protrusions provided on the grid-like partition 14 When the interval between two adjacent protrusions 15 of the object 15 is x, in the present embodiment, in order to prevent the projections 31 of the printing plate and the protrusions 15 from interfering with each other, a <b < x relationship is satisfied.

The thickness of the organic light-emitting medium layer 16 formed in this way is such that the structure of the organic light-emitting medium layer 16 is a single layer structure or a plurality of layers in order to eliminate problems when the substrate 11 and the sealing substrate 21 are bonded. Even in the case of a laminated structure composed of these layers, the height difference from the grid-like partition walls 14 is 1 μm or less, preferably 0.05 to 0.2 μm.
The second electrode 17 is formed on the organic light emitting medium layer 16 so as to function as a cathode when the first electrode 13 is an anode and to function as an anode when the first electrode 13 is a cathode. When the second electrode 17 is used as a cathode, it is preferable to use a material having a small work function for the purpose of enhancing the electron injection effect. For example, alkaline metals such as Li and Na, alkaline earths such as Mg, Al, Ba, Ca, and Sr are used. Examples of the material having a small work function include alkali metal fluorides such as similar metals and LiF. Further, the structure of the second electrode 17 may be a single layer structure of these metals, a stacked structure, or a structure in which a plurality of metals are combined.

  As a material for the second electrode 17, it is necessary to use a material having translucency in order to allow light emitted from the organic light emitting medium layer 16 to pass therethrough. However, since such a material having a low work function has low translucency, a structure that compensates for low translucency may be used by using a metal-to-metal, a laminated structure of a metal and a compound, or an alloy system. In addition, a method of minimizing a decrease in translucency can be taken by making a single metal having a small work function into a very thin film. In the case of such a structure, it is preferable to have a laminated structure with a transparent conductive material such as ITO for the purpose of increasing efficiency.

  The protective film 18 is a thin film that is formed so as to cover the second electrode 17 and the grid-like partition walls 14 on the organic EL element substrate and has electrical insulation. Further, the protective film 18 is formed for the purpose of preventing permeation of oxygen and moisture and preventing deterioration of each layered portion formed on the organic EL element substrate. The method for forming the protective film 18 is not particularly limited, and the protective film may have a single layer structure or a laminated structure including a plurality of layers.

The thickness of the protective film 18 is not particularly limited as long as it can withstand the stress from the sealing substrate 21 as the sealing base material, but light emitted from the organic light emitting medium layer 16 passes through the protective film 18. Therefore, for example, it is preferably 0.5 μm or more and 10 μm or less, desirably 0.5 μm or more and 10 μm or less.
The material of the protective film 18 is not particularly limited as long as it is a material that can withstand the stress from the sealing substrate 21 as the sealing base material. However, since light emission from the organic light emitting medium layer 16 passes, for example, Al ₂ It is preferable to use an inorganic oxide such as O ₃ , TiO, or ZnO, or an inorganic nitride such as Si ₃ N ₄ .

Next, the sealing substrate 21 of the organic EL device will be described.
Since the light emission from the organic light emitting medium layer 16 passes, the sealing substrate 21 needs to have translucency. A color filter substrate may be used as such a sealing substrate. The color filter substrate refers to a substrate capable of selecting a specific wavelength and a substrate capable of converting and transmitting a light emission wavelength. In an organic EL device, the color filter substrate functions to emit light from the organic light emitting medium layer 16. To do. Such a color filter substrate refers to a substrate in which the color filter layer 22 and the black matrix layer 23 are formed on at least one surface of a light-transmitting substrate.

  As the sealing substrate, a material that does not damage the organic EL element substrate 10 due to deformation or stress of the substrate after the sealing substrate is bonded to the organic EL element substrate 10 is used. Moreover, the sealing base material is formed with the material which has translucency with respect to the wavelength of the light emitted from the organic light emitting medium layer 16 and the light converted by the color filter layer 22, and such a sealing base material. As the material, a material that can withstand the formation conditions (temperature, solvent, stress, etc.) of the color filter layer 22 and the black matrix layer 23, for example, a material containing a resin such as glass, polyethylene terephthalate, polymethyl methacrylate, etc. Glass is preferred.

  The color filter layer 22 refers to a structure in which a thin film of at least two colors is formed in a pixel region formed on the sealing substrate 21 and partitioned by the black matrix layer 23, and the arrangement shape of the pixel region The arrangement, unit pixel area, and thin film size are not limited. Further, the thin film of two or more colors may have either a single layer structure or a multi-layer structure, and is preferably formed with red, green, and blue thin films having the same configuration as the organic light emitting medium layer 16 of the organic EL element substrate 10. . Such a color filter layer 22 can be formed by a known technique, and the material and the forming method are not particularly limited.

  The black matrix layer 23 is formed around a region where the color filter layer 22 is formed. For this reason, a region partitioned by the black matrix layer 23 becomes a pixel region in the color filter substrate. Such a black matrix layer 23 prevents color mixing or light leakage between layers when forming the color filter layer 22, or TFT wiring and terminal portions on the organic EL element substrate 10 when viewed from the front panel side. It is formed on the surface of the sealing substrate 21 for the purpose of preventing reflection due to covering. The shape, arrangement, area, and size of the black matrix layer satisfying such conditions are not particularly limited. Further, the structure of the black matrix layer 23 may be either a single layer structure or a laminated structure composed of a plurality of layers.

  However, when the sealing substrate 21 on which the color filter layer 22 and the black matrix layer 23 are formed and the organic EL element substrate 10 are bonded together with an adhesive, the sealing substrate is used so that light emission from the organic light emitting medium layer 16 is not blocked. Therefore, it is preferable to bond the black matrix layer 23 in a state where the black matrix layer 23 is disposed with the grid-like partition 14 on the organic EL element substrate 10. Therefore, in the present invention, the black matrix layer 23 has a lattice shape which is the same shape as the lattice-like partition walls 14.

Next, the sealing structure of the organic EL device will be described.
The adhesive layer 30 is formed between the organic EL element substrate 10 and the color filter substrate 20 in order to prevent deterioration of the organic EL device due to permeation of oxygen and moisture in the external environment. For this reason, the adhesive layer 30 is preferably made of a material having low moisture permeability, such as a material that does not change in quality due to the surrounding environment, and a material that hardly undergoes deformation, shrinkage, expansion, etc. over time. desired.

  Such an adhesive layer 30 can be formed by a known technique. For example, the adhesive layer 30 can be formed by a spin coating method, a dispensing method, a photolithography method, a printing method, a laminating method, or the like. Also, a known material can be used for the adhesive layer 30, and a liquid adhesive can be preferably used. In this case, the adhesive layer 30 needs to be translucent to the emission wavelength from the organic light emitting medium layer 16. Further, in order to efficiently transmit light emitted from the organic light emitting medium layer 16, a material having a refractive index of the adhesive layer 30 lower than that of the protective film 18 is preferably used as a material of the adhesive layer 30.

Examples of the material whose refractive index of the adhesive layer 30 is lower than that of the protective film 18 include thermosetting adhesive resins such as thermosetting epoxy resins, thermoplastic adhesive resins such as polyethylene resins and acrylic resins, and photocuring. Photocurable adhesive resin such as epoxy resin.
As an example of the method for forming the adhesive layer 30, there is a method in which a peripheral sealing agent is applied along a pixel region on one substrate, and then the substrate on which the adhesive is applied and the other substrate are bonded to each other. . In this case, the application method of the adhesive or the peripheral sealing agent is not particularly limited, and a known method can be used. The substrate to which the adhesive or the peripheral sealing agent is applied may be either the organic EL element substrate 10 or the color filter substrate 20, but after the adhesive or the peripheral sealing agent is applied, the color filter layer 22 and the organic light emitting medium The two substrates are bonded together with the black matrix layer 23 and the lattice-shaped partition wall 14 facing each other and the layer 16 facing each other.

In the present embodiment, the adhesive layer 30 is formed by applying a peripheral sealing agent made of an adhesive resin on a substrate and then applying an adhesive made of a resin material having a lower viscosity than the peripheral sealing agent to the entire inside of the peripheral sealing agent. Apply to. This technique makes it possible to prevent the adhesive from flowing out by the cured peripheral sealing agent.
Known materials can be selected as the material for the peripheral sealant and adhesive, but thermosetting adhesive resins such as thermosetting epoxy resins, and thermoplastic adhesive resins such as polyethylene resins and acrylic resins. It is preferable to use a photocurable adhesive resin such as a photocurable epoxy resin. The peripheral sealing agent is applied to a position outside the pixel region of the color filter, and only the adhesive is applied on the pixel region.

  When the organic EL element substrate 10 and the color filter substrate 20 are bonded together by the adhesive layer 30, the adhesive layer 30 is a low moisture-permeable material, and the organic EL element is altered by moisture or oxygen remaining inside. In addition to the external environment, it is necessary to have a situation in which oxygen and moisture are not substantially present in the organic EL device. Therefore, the organic EL element substrate 10 and the color filter substrate 20 are bonded to each other in a vacuum, a nitrogen atmosphere, an inert gas atmosphere, or the like in an environment where there is almost no moisture or oxygen in the atmosphere. However, when the above conditions are satisfied, a known technique can be used.

In the present embodiment, the black matrix layer 23 is formed in a lattice shape so as to partition the color filter layer 22, and the protrusions 15 are disposed on the intersections 143 of the lattice partition walls 14. When the organic EL element substrate 10 and the color filter substrate 20 are bonded together in a state where the partition wall 14 and the black matrix layer 23 are opposed to each other, as shown in FIG. The substrate 11 and the sealing substrate 21 can be bonded together in a state in which the substrate 11 is in contact with the intersection of 23. As a result, the distance (gap) between the substrate 11 on which the organic EL element is formed and the sealing substrate 21 on which the color filter layer 22 and the black matrix layer 23 are formed can be kept constant over the entire surface of the substrate. Since moisture and air in the atmosphere hardly enter the bonded portion between the EL element substrate 10 and the color filter substrate 20, it is possible to manufacture an organic EL device in which deterioration of the organic EL element is unlikely to occur.
In the above-described embodiment, the organic EL device having the top emission structure is described. However, the same method can be used for the organic EL device having the bottom emission structure.

[Example 1]
As the substrate 11 of the organic EL element substrate 10, a non-alkali glass with a thickness of 0.7 mm in which a TFT is formed on one surface of the substrate is used, and a polyimide film with a thickness of 0.1 μm is formed on the substrate 11 as a planarizing film 12. After forming by the lithography method, an ITO film having a thickness of 0.15 μm was formed on the planarizing film 12 as the first electrode 13 by the sputtering method. Note that a through hole is formed in the planarizing film 12, and the TFT and the first electrode 13 are electrically connected.

  Next, a grid-like partition 14 made of polyimide resin is formed on the first electrode 13 by a photolithography method with a thickness of 2 μm, and a projection 15 made of acrylic resin is formed on the intersection 143 of the grid-like partition 14. Was formed by photolithography at a height of 5 μm. At this time, the number of light emitting pixel regions surrounded by the grid-like partition 14 was 960 × 540. Further, the protrusion 15 was formed to be a columnar body, and the tip portion was formed to be a square. Further, the protrusions 15 are provided on all the intersecting portions 143 of the lattice-shaped partition wall 14, and the protrusions 15 are formed so that the distance between the two protrusions is 76 μm.

  Next, as the organic light emitting medium layer 16, PEDOT (0.02 μm) is used as the hole transport layer, and poly [2-methoxy-5- (2′ethyl-hexyloxy) -1,4-phenylenevinylene] is used as the organic light emitting material. A solution (0.1 μm) dissolved in anisole was formed by letterpress printing. Thereafter, an ITO film (0.1 μm) was formed as the second electrode 17 on the organic light emitting medium layer 16, and a SiNx film (1 μm) was formed as the protective film 18 on the ITO film. Thereby, an organic EL element substrate 10 as shown in FIG.

  Next, a non-alkali glass is used as the sealing substrate 21, and the black matrix layer 23 is used as the black matrix layer 23 on the substrate 21 in a lattice pattern using a color mosaic CK-7800 (manufactured by Fujifilm Electronics Materials Co., Ltd.). The black thin film (thickness: 1.5 μm) and the black thin film (thickness: 1.5 μm) were formed around the pixel region. After that, as the color filter layer 22, a red thin film using the color mosaic CR-7001, a green thin film using the color mosaic CG-7001, and a blue thin film using the color mosaic CB-7001 (each wisteria film). Electronics Material Co., Ltd., thickness 1.5 μm) was formed to obtain a color filter substrate 20 as shown in FIG.

Next, the organic EL element substrate 10 is placed in a device under a nitrogen atmosphere, and a photo-curing adhesive epoxy resin is used as a peripheral sealing agent, and a thermosetting adhesive epoxy resin is used as an adhesive, and bonded to the peripheral sealing agent. Each agent was applied onto the organic EL element substrate 10 by a dispensing method. At this time, the adhesive was made of a material having translucency for light emission from the organic light emitting medium layer 16. Thereafter, the color filter substrate 20 and the organic EL element substrate 10 were placed in an apparatus under vacuum, and after the adhesive was applied, the color filter substrate 20 and the organic EL element substrate 10 were disposed facing each other. At this time, the color filter layer 22 of the color filter substrate 20 and the organic light emitting medium layer 16 of the organic EL element substrate 10 are opposed to each other, and the black matrix layer 23 and the grid-shaped partition walls 14 are opposed to each other. The filter substrate 20 and the organic EL element substrate 10 were disposed. Then, after pressurizing the substrates so that the tip of the protrusion 15 is in contact with the intersection of the black matrix layer 23 via the adhesive layer 30, the adhesive is cured in an oven at 80 ° C. under normal pressure, An organic EL device as shown in FIG. 1C was obtained.
Although this organic EL device was left in a constant temperature and humidity chamber maintained at 60 ° C. and 90% RH for 1500 hours, no bubbles or pixel defects were found in the organic EL device.

[Comparative Example 1]
The protrusion 15 is not formed on the organic EL element substrate, and the substrate having the protrusion formed on the black matrix layer 23 on the color filter substrate 20 is used in the same manner as the bonding method described in the first embodiment. The organic EL element substrate and the color filter substrate were bonded together to obtain an organic EL device. And when the state after bonding was confirmed, several air bubbles were seen in the contact bonding layer. Further, when the organic EL device obtained in Comparative Example 1 was left in a constant temperature and humidity maintained at 60 ° C. and 90% RH for 1500 hours, gas in the external environment (moisture and oxygen) due to non-uniform bonding. Due to the mixing, no light emission occurred in about 20% of the entire light emitting pixel region.

[Comparative Example 2]
The organic EL element substrate and the color filter substrate are bonded by the same means as the bonding method described in Example 1 using the organic EL element substrate in which the protrusions 15 are provided at locations other than on the intersections 143 of the lattice-shaped partition walls 14. The organic EL device was obtained by bonding.
In this organic EL device, the stripe-shaped convex portion 31 of the relief printing plate and the projection 15 were in contact with each other during printing of the hole transport layer. When the state after pasting in this organic EL device was confirmed, light emission display unevenness due to printing was observed.

DESCRIPTION OF SYMBOLS 10 ... Organic EL element substrate 11 ... Substrate 12 ... Planarization film 13 ... First electrode 14 ... Grid-like partition 141 ... First partition line 142 ... Second partition line 143 ... Intersection 15 ... Projection 16 ... Organic light emitting medium layer DESCRIPTION OF SYMBOLS 17 ... Second electrode 18 ... Protective film 20 ... Color filter substrate 21 ... Sealing substrate 22 ... Color filter layer 23 ... Black matrix layer 30 ... Adhesive layer 31 ... Convex part of relief printing plate

Claims (10)

A substrate having a plurality of light emitting pixel regions formed by laminating a first electrode, an organic light emitting medium layer, and a second electrode and a grid-like partition wall surrounding the light emitting pixel region on one surface, the substrate and the light emitting pixels A plurality of first partition lines that are parallel to each other, and a plurality of second partition lines that are orthogonal to the first partition lines. A method of manufacturing an organic EL device formed by:
After providing a plurality of protrusions only on the first partition line, pattern formation is performed along the first partition line by letterpress printing on at least one of the plurality of layers forming the organic light emitting medium layer. Then, after forming the second electrode on the organic light emitting medium layer, the substrate and the sealing base material are bonded together in a state where the tip of the protrusion is in contact with the sealing base material. A method of manufacturing an organic EL device characterized by the above.   2. The method of manufacturing an organic EL device according to claim 1, wherein the plurality of protrusions are disposed on intersections of the first partition line and the second partition line, and then the organic light emitting medium layer is formed. At least one of the layers is patterned along the first partition line or the second partition line by a relief printing method, and then the second electrode is formed on the organic light emitting medium layer, and then the protrusion A manufacturing method of an organic EL device, wherein the substrate and the sealing substrate are bonded together in a state in which a tip of an object is in contact with the sealing substrate.   3. The method of manufacturing an organic EL device according to claim 1, wherein, when patterning at least one of the plurality of layers forming the organic light emitting medium layer by the relief printing method, a plurality of protrusions are formed on the surface. A method of manufacturing an organic EL device, comprising patterning at least one of a plurality of layers forming the organic light emitting medium layer using a relief printing plate formed in a stripe shape.   4. The method of manufacturing an organic EL device according to claim 3, wherein the organic light emitting medium layer is formed using a relief printing plate whose width in the short side direction of the convex portion is smaller than the length of one side of the organic light emitting medium layer. A method of manufacturing an organic EL device, comprising patterning at least one of the layers.   5. The organic EL device manufacturing method according to claim 3, wherein a width of the convex portion in a short side direction is smaller than an interval between two adjacent projections among the plurality of projections, and the organic printing device is used. A method of manufacturing an organic EL device, comprising patterning at least one of a plurality of layers forming a light emitting medium layer.   In the manufacturing method of the organic electroluminescent apparatus as described in any one of Claims 3-5, several height which forms the said organic light emitting medium layer using the relief printing plate in which the height of the said convex part is lower than the height of the said protrusion. A method of manufacturing an organic EL device, comprising patterning at least one of the layers. A substrate having a plurality of light emitting pixel regions formed by laminating a first electrode, an organic light emitting medium layer, and a second electrode and a grid-like partition wall surrounding the light emitting pixel region on one surface, the substrate and the light emitting pixels A plurality of first partition lines that are parallel to each other, and a plurality of second partition lines that are orthogonal to the first partition lines. An organic EL device formed by
An organic EL device, wherein a plurality of protrusions defining a distance between the substrate and the sealing substrate are disposed on a first partition line of the lattice-shaped partition.   8. The organic EL device according to claim 7, wherein the plurality of protrusions are disposed on the intersection of the first partition line and the second partition line of the lattice-shaped partition.   9. The organic EL device according to claim 7, wherein the sealing substrate includes a color filter layer that colors light from the light emitting pixel region, and a black matrix layer that partitions the color filter layer in a lattice shape. An organic EL device characterized by that.   The organic EL device according to claim 9, wherein the protrusion is formed at a position facing the black matrix layer.

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