JP2008066103A - Organic el element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To inexpensively provide an organic EL element in which sharpness, high brightness, and a long life are achieved even in an organic EL panel of high precision. <P>SOLUTION: This bottom emission type organic EL element of a color conversion type is equipped with one or more of light-emitting units sequentially forming a black matrix 101, a color filter 102, a color conversion layer or a clear layer 103, an overcoat layer 104, a first electrode 106, an organic EL layer 109 including an organic light emitting layer, and a second electrode 110 on a substrate 11, and in which light generated from the organic EL layer 109 is emitted from the substrate 11. The organic EL element has a reflecting film 31 so as to reflect a part of light which passes through the color conversion layer 103 and is absorbed in the black matrix 102 and to extract a part of the light from the substrate 11. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an organic EL element and a method for manufacturing the same.

  The substrate structure of the color conversion type organic EL display, in particular, the light emission unit of the passive type bottom emission structure is, for example, as shown in FIGS. Black matrix 11 / color filter 12 / color conversion (CCM) layer 13 / flattening layer 14 / passivation film 15 / transparent electrode (anode) 16 / shadow mask 17 / light emitting layer 18 / reflection electrode (cathode) 19 on a glass substrate This is the configuration. Although not shown, a pattern for separating the cathode into the operation electrodes may be provided. The light emitting layer 18 further includes a hole injection layer / a hole transport layer / an organic light emitting layer / an electron injection layer. The light emitted from the light emitting layer is a blue-green single color, which is converted into green and red by the color conversion layer. Blue is extracted from the light of the original light source by a color filter. At this time, the black matrix 11 exists in order to prevent the transparent electrode, the shadow mask, the color filter, and the end portion of the color conversion layer from being scattered by the external light, thereby improving the contrast.

  For simplicity, when a simulated point light source is considered in the organic light emitting layer 18, the emitted light spreads in almost all directions although there is a direction dependency of intensity. When this reaches the color conversion layer 13, it is color-converted from blue-green to red or the like and further scattered in all directions. Therefore, the light may be emitted not only in the straight direction as in the optical path a but also in the optical path b. Further, light emitted in an oblique direction may be absorbed by the black matrix after color conversion as in the optical path c. Since the light emitted at the end is absorbed by the black matrix as in the optical path e even when the emission angle is shallow, the ratio of light that can be extracted outside decreases.

In addition, a light emitting layer and a transparent electrode (IZO etc.) have a refractive index close, and the value is about 2.0-2.2. The passivation film 15 is made of ordinary SiO _2, SiN, or the like, it refractive index of about 1.5 to 1.8. The refractive index of the layer below the planarizing layer 14 is also about 1.5. Accordingly, a part of the emitted light cannot be emitted to the outside by repeating total reflection as in the optical path d or scattered at the end of the transparent electrode.

  In the case of the conventional structure as shown in FIG. 1A, the minimum value of the line width of the black matrix is determined from the alignment accuracy in the photo process when forming each layer and the formation accuracy of the line width, that is, the process rule. Therefore, the black matrix line width cannot be reduced even if the size of the light emitting unit is reduced. In particular, in the case of the color conversion method, since the color conversion layer is thick, it is difficult to control the line width. Generally, in the case of a fineness up to about 100 ppi, an aperture ratio of 60 to 80% can be realized, but the aperture ratio decreases as the resolution becomes higher, and the process rule does not change when trying to achieve about 150 to 200 ppi. As far as it is possible, it may be reduced to about 20 to 40%.

  The light that reaches the part other than the opening through which the light on the substrate can be transmitted is absorbed by the black matrix. However, as the definition becomes higher (as shown in FIG. 1B), the ratio increases and the light extraction efficiency increases. Will be reduced. In order to compensate for this, if the current density of the light emitting part is increased to improve the luminance, the lifetime will be reduced. In addition, when using a higher-precision photomask or exposure machine in order to improve the process rule, there is a problem that the cost is greatly increased.

In addition, as a proposed structure for extracting part of the light that has reached the part other than the opening that can transmit light on the substrate, a method in which light-reflective or light-scattering white powder is mixed in the gaps between the conversion layers (For example, refer to Patent Document 1). According to this method, it is possible to reflect the light leaking from the color conversion layer, but it is more preferable if there is a substrate structure capable of saving the light absorbed by the black matrix.
Japanese Patent Laying-Open No. 2005-123089

  SUMMARY OF THE INVENTION An object of the present invention is to provide an organic EL element that can be sharp, have high brightness, and have a long lifetime even in a high-definition organic EL panel at low cost.

The present invention has been made to solve the above problems. That is, in order to achieve the above object, the organic EL device according to the present invention includes a black matrix, a color filter, a color conversion layer or a clear layer, an overcoat layer, a first electrode, and an organic material on a substrate. An organic EL layer including a light emitting layer and one or more light emitting units in which a second electrode is sequentially formed, and a color conversion type bottom emission organic EL element in which light generated from the organic EL layer is emitted from the substrate. A reflective film is provided so as to reflect a part of the light that passes through the color conversion layer or the clear layer and is absorbed by the black matrix and takes out from the substrate.
An organic EL device manufacturing method according to the present invention includes a black matrix layer, a color filter layer, a color conversion layer or a clear layer, an overcoat layer, a first electrode, and an organic light emitting layer on a substrate. A method for manufacturing a bottom emission type organic EL element of a color conversion type comprising an EL layer and one or more light emitting units in which a second electrode is sequentially formed, and light generated from the organic EL layer is emitted from the substrate. A step of forming a black matrix layer on the substrate so as to form an opening window through which the light can be emitted, and a step of forming a color filter layer so as to cover the opening window by a photolithographic method. And forming a reflective film on the color filter layer so as not to block the light perpendicularly incident on the aperture window, and on the color filter layer and the reflective film, Using a photomask used for forming the serial color filter layer, a method which comprises a step of forming the color conversion layer is classified by the light emitting unit.

  In a high-definition panel, the light extraction efficiency is improved, high luminance or a long life can be expected, and an organic EL display capable of displaying a sharp image can be realized.

Hereinafter, the present invention will be described in detail with reference to the drawings. The same members are denoted by the same reference numerals. In addition, this invention is not restrict | limited to the form demonstrated below.
The organic EL element of the present invention includes a black matrix, a color filter, a color conversion layer or a clear layer, an overcoat layer, a first electrode, an organic EL layer including an organic light emitting layer, a second matrix on a substrate. It is a bottom emission type organic EL element of a color conversion system that includes one or more light emitting units in which electrodes are sequentially formed and in which light generated from the organic EL layer is emitted from the substrate.
Here, in the case of a normal color panel, one pixel has three openings (subpixels) for RGB. In this specification, when one subpixel is referred to, it is called a light emitting unit. In this specification, the light emitting unit is not limited to a subpixel that emits light in the color conversion layer, but includes a subpixel that transmits light through the clear layer. In the present specification, the term “color conversion layer” is a concept including a clear layer unless it is specified that color conversion is performed.

In the present invention, a reflective film is provided on the process surface side within the range of the black matrix. As the stacking direction, it is preferable to stack in parallel with the organic EL layer between the color filter and the color conversion layer or between the black matrix and the color filter.
Further, when two or more light emitting units are provided, a reflective film may be provided at the end of the color conversion layer in the adjacent light emitting units. The end reflection film of the color conversion layer is preferably formed so as to cover the entire side surface of the color conversion layer by forming the color conversion layer in an island shape for each light emitting unit.

The organic EL element of the present invention preferably includes a reflective film between the color conversion layer and the color filter within a light shielding range of a black matrix. In the present specification, the “black matrix light-shielding range” is a range in which light incident perpendicularly to the laminated surface from the organic EL layer is blocked by the black matrix.
FIG. 3A shows a first form of the light emitting unit of the organic EL element of the present invention. First, the black matrix 101 and the color filter 102 are formed on the glass substrate 11 by photolithography. Next, a reflective film such as Al, Mo, Cr, or Ag is formed by sputtering or the like, and a resist is applied and exposed to form a reflective film 31.
The thickness of the reflective film is a value that can reflect light and hardly affect the shape of other films, and is preferably about 10 to 500 nm, more preferably about 20 to 100 nm. Further, it is desirable to design the end portion of the reflective film so as to be inside the end portion of the black matrix. If possible, it is more desirable to design the end portion within 1 to 3 μm (thinning the line width). This is to prevent a part of the reflective film from protruding from the black matrix or being seen from an oblique direction due to the positional deviation.
Next, a color conversion (CCM) layer 103 / flattening layer 104 is formed by photolithography. After the moisture is removed by heat treatment, the passivation film 105 is formed of a single film or a laminated film of SiO, SiO ₂ , SiN or the like using sputtering, CVD, or vapor deposition.
Next, a transparent electrode (anode) 106 such as ITO or IZO is formed on the passivation film 105. At this time, the exposure and etching conditions in the photo process can be adjusted, and the end portion can be tapered. Next, an organic shadow mask material 108 is applied, and a pattern for opening the display portion opening is formed by photolithography. Of course, the shadow mask may be made of an inorganic material such as SiO ₂ or SiN that absorbs less moisture that damages the organic EL. Next, a cathode separation wall is formed in a direction orthogonal to the anode wiring. Here, the organic EL layer 109 including the organic light emitting layer and the cathode metal 110 such as Al are vapor-deposited to form the light emitting units 1 in a matrix.

  Of the light emitted from the light emitting layer 109 in the structure of FIG. 3A, all of the light conventionally incident on the substrate (in FIG. 1B) can be extracted. In addition to this, there is light that is reflected by the horizontal reflection film 31 after color conversion and then reflected and emitted by the reflective electrode 110, mainly as in the optical path g and the optical path h, and this increases the light extraction efficiency. . These are effective for improving the luminance when viewed from the side (side) of the panel. Further, there is also light that is color-converted and scattered after being reflected by the horizontal reflecting film 31 and emitted to the substrate.

FIG. 3B shows a second embodiment of the present invention. In the first embodiment, the horizontal reflection film 31 is formed and the color conversion layer 103 is formed, and then the reflection film 32 is further formed on the side surface of the color conversion layer.
Usually, in the color conversion method, the thickness of the color conversion layer is about 5 μm to 20 μm. When the organic EL element of the present invention includes two or more light emitting units, the interval between adjacent color conversion layers is about 2 μm to 10 μm.
In order to form a uniform reflective film on the entire side surface of the color conversion layer, it is preferable to apply sputtering or CVD capable of forming a film on the gap or the side surface. A preferable thickness of the side reflection film 32 is the same as that of the horizontal reflection film 31.
Next, the planarization layer 104 is formed by photolithography, but it is necessary to adjust the film thickness and the like so that the step of the side reflection film 32 does not appear. Thereafter, as in the first embodiment, the layers from the passivation film 105 to the reflective electrode (cathode wiring) 110 are formed.
In this form, in addition to the light emission path of the first form, for example, an optical path i and an optical path j are also conceivable. These optical paths can contribute to an increase in light emitted from the front of the panel (the lower side of the paper).

The organic EL element of the present invention may be provided with a reflective film between the color filter and the black matrix within the light shielding range of the black matrix.
FIG. 4A shows a third embodiment, and FIG. 4B shows a fourth embodiment in which the reflective film in the first embodiment and the second embodiment is formed on the black matrix 101, respectively. In this embodiment, since the reflection film 41 is flat and comes under the color filter 102, when the color conversion layer 103 is formed by the photolithographic method, there is little irregular reflection at the end during exposure, and the shape controllability is good. There is an advantage. In this case, the color-converted end light passes through the color filter 102 as in the optical path g, is reflected by the horizontal reflection film 41, and can be emitted from the opening, but is color-converted as in the optical path k. The light that has been transmitted without passing through the color filter 102 is absorbed only before it reaches the horizontal reflection film 41, so that the extraction efficiency is lower than in the first and second embodiments. Further, in the comparison between the third embodiment shown in FIG. 4 (a) and the fourth embodiment shown in FIG. 4 (b), the fourth embodiment also has a side reflection path by the side reflection film 42 like the optical path l. So it is a little more efficient.

3B and 4B described above, the light reaching the adjacent light emitting unit without color conversion as in the optical path c and the optical path f in FIG. It is possible to prevent a neighboring light emitting unit from being illuminated and to provide a sharp image.
Since the ratio of light reaching the adjacent light emitting unit without color conversion increases as the definition becomes higher and the interval between the light emitting units is reduced, the higher the definition, the higher the definition becomes, as shown in FIGS. A form like b) becomes more effective. Even if the color-converted light enters the adjacent light emitting unit, there is no problem because it is absorbed by the color filter 102 of the adjacent light emitting unit.
Regardless of the definition, the scattered light from the end of the transparent electrode 106 described above may enter the adjacent light emitting unit, which is also configured as shown in FIGS. 3B and 4B. Can be solved.

The organic EL element of the present invention comprises two or more light emitting units, the color conversion layer is provided separately for each light emitting unit, and a reflective film is provided on the entire side surface of each color conversion layer. Is preferred.
FIG. 5B is a perspective view showing the shape of one pixel (RGB) of the organic EL element of the present invention in a state in which the side reflection films 32 and 42 are formed around the entire periphery of each light emitting unit.
The organic EL element as shown in FIG. 5B has, for example, a black matrix layer 21 in a lattice shape so as to border an opening 22 through which light can be emitted onto the substrate 11 as shown in FIG. Forming a color filter layer so as to cover the opening portion 22, and forming reflective films 31 and 41 on the color filter layer so as not to block light incident on the opening portion, On the color filter layer and the reflective film, a color conversion layer is formed by dividing each light emitting unit to obtain a color filter layer / color conversion layer stack 51, and then the color filter layer / color conversion layer stack 51 It is obtained by forming the side reflection films 32 and 42 at the end and the entire periphery.
5 (a) and 5 (b), not only two-dimensional light scattering but also the conventional strip-shaped color filter / color conversion layer laminate 23 shown in FIG. It is possible to cope with light scattered in the longitudinal direction of the strip which has not been considered.

In the organic EL device of the present invention, the horizontal reflection film opening area (B) is larger than the black matrix opening area (A) for each light emitting unit. The reason why the area (B) is larger than the area (A) is to improve contrast while hiding the metal reflective film.
In the organic EL device of the present invention, it is also preferable that the side reflection film opening area (C) is as large as the area (B) or larger than the area (B).
The reason why the area (C) is preferably larger than the area (B) is to put as much EL light as possible into the color conversion layer.
In this specification, the black matrix opening area is an area through which light incident from the organic EL layer perpendicularly to the laminated surface can be transmitted without being blocked by the black matrix.
In this specification, the horizontal reflection film opening area is an area through which light vertically incident on the laminated surface from the organic EL layer can be transmitted without being blocked by the horizontal reflection film.
In this specification, the side reflection film opening area is an area through which light incident from the organic EL layer perpendicularly to the laminated surface can be transmitted without being blocked by the side reflection film.

  The organic EL element of the present invention is suitable for producing a high-definition organic EL panel, and can be particularly suitably used for producing an organic EL panel having 130 to 250 ppi.

Although the embodiment of the present invention has shown an organic EL panel structure as an example, it is not limited to organic EL light emission as long as it has a color conversion layer, and other methods such as an inorganic EL display, FED, and liquid crystal display are used. However, the same is true and is within the scope of the present invention.
In the structure of the present invention, the color-converted light at the end of the color conversion layer is reflected by the reflective film on the black matrix, part of which is returned to the reflective electrode (cathode wiring) and further emitted from the opening. In addition, the light transmitted without being color-converted is reflected by the reflective film, and a part of the light may be color-converted by the color conversion layer and emitted directly from the black matrix opening. Furthermore, when there is a reflection film at the end of the color conversion layer, the light reflected by the reflection film on the black matrix is reflected without leaking from the side surface, and part of the color is converted and emitted from the opening. In addition, in the structure of the present plan, a part of the light that has been absorbed by the black matrix and leaked to the vicinity of the adjacent light emitting unit is emitted from the opening through various paths. On the contrary, the side reflection film is useful for preventing the scattered light from the adjacent transparent electrode end or the like from entering.

A black matrix layer, a color filter layer, a color conversion layer or a clear layer, an overcoat layer, a first electrode, an organic EL layer including an organic light emitting layer, and a second electrode are sequentially formed on the substrate. A method of manufacturing a color conversion type bottom emission type organic EL device comprising at least one light emitting unit, wherein light generated from an organic EL layer is emitted from the substrate, wherein the light is emitted onto the substrate. Forming a black matrix layer so as to form an openable window, and forming a color filter layer so as to cover the open window by a photolithography method,
Forming a reflective film on the color filter layer so as not to block the light perpendicularly incident on the aperture window; and forming the color filter layer on the color filter layer and the reflective film. A method for producing an organic EL element comprising a step of forming a color conversion layer by dividing the light emitting unit by using a conventional photomask is also one aspect of the present invention.

The labor required to obtain the substrate structure as illustrated in FIGS. 3 and 4 is only one or two steps of attaching the reflective film, and is inexpensive.
In some cases, the metal forming the terminals and the reflective film can be formed at the same time, so that there is no increase in the number of processes.
In addition, the cost can be reduced by using the photomask used for forming the color filter layer in the step of forming the color conversion layer.

In the organic EL device of the present invention, a black matrix 101, a color filter 102, a color conversion layer or clear layer 103, and an overcoat layer 104 are sequentially formed on a substrate 11.
The substrate 11 is not particularly limited as long as it is a transparent material with respect to the wavelength of light emitted from each light emitting unit. For example, non-alkali glass; soda glass; quartz; transparent plastic material such as polycarbonate, acrylic, and PET; SiO ₂ glass Etc.

The black matrix 101 prevents light emitted from each light emitting unit from being scattered in the vicinity of the adjacent light emitting unit, and the ends of transparent electrodes, shadow masks, color filters, and color conversion layers described later are scattered by incident external light. It is a layer that plays a role in preventing it from appearing.
Examples of the material of the black matrix 101 include a photosensitive resin containing a black pigment or dye such as carbon black.

  The color filter 102 is a filter having a function of improving the color purity of emitted light by selectively absorbing or transmitting the wavelength of emitted light. For example, in a full color display using three primary colors, the color purity is enhanced by transmitting wavelengths of 400 nm to 550 nm for blue (B), 500 nm to 600 nm for green, and 600 nm for red. As a manufacturing method, a method of forming a pattern by repeatedly applying, exposing, and developing a colored photosensitive material in which a dye or pigment is dispersed in a photosensitive resin layer is a common method, particularly recently in terms of durability. There are more color filters in which pigments are dispersed than dyes. Typical pigments used as dispersing agents include azo lake, insoluble azo, condensed azo, phthalocyanine, quinacridone, dioxazine, isoindolinone, anthraquinone, verinone, thioin, and berylene. There are mixed systems.

The clear layer 103 is a layer that is transparent to light in the near ultraviolet region or visible region emitted from the organic light emitting layer. As a material of the clear layer 103, an acrylic resin can be used.
The color conversion layer 103 is a layer having a function of emitting visible light of different wavelengths by the fluorescent dye absorbing light in the near ultraviolet region or visible region emitted from the organic light emitting layer. This can emit fluorescence in various wavelength regions depending on the combination of incident light with a fluorescent dye. In addition, for example, by absorbing light emitted in blue and emitting fluorescence in the red region, it is also possible to output light that is stronger than selectively transmitting wavelengths and emitting light in the red region. These are applied to color conversion type organic EL elements. As a production method, a method is generally used in which a colored photosensitive material in which a fluorescent pigment is dispersed in a photosensitive resin layer is used as a material, and this is repeatedly applied, exposed and developed to form a pattern. Examples of fluorescent dyes that absorb light in the blue or blue-green region and emit green region fluorescence include 3- (2′-benzothiazolyl) -7-diethylamino-coumarin (coumarin 6) and 3- (2′-benzimidazolyl). ) -7-diethylamino-coumarin (coumarin 7), 3- (2′-N-methylbenzimidazolyl) -7-diethylamino-coumarin (coumarin 30), 2,3,5,6-1H, 4H-tetrahydro-8- Coumarin-based dyes such as trifluoromethylquinolidine (9,9a, 1-gh) coumarin (coumarin 153), or coumarin dye-based dyes such as basic yellow 51, and naphthalimide such as solvent yellow 11 and solvent yellow 116 System dyes and the like. Furthermore, various dyes (direct dyes, acid dyes, basic dyes, disperse dyes, etc.) can be used if they are fluorescent. Examples of fluorescent dyes that absorb light in the blue to blue-green region and emit fluorescence in the red region include rhodamine B, rhodamine 6G, rhodamine 3B, rhodamine 101, rhodamine 110, sulforhodamine, basic violet 11, and basic red 2. Rhodamine dyes such as rhodium dyes, cyanine dyes, pyridine dyes such as 1-ethyl-2- [4- (p-dimethylaminophenyl) -1,3-butadienyl] -pyridinium perchlorate (pyridine 1), or oxazine dyes And pigments. Furthermore, various dyes (direct dyes, acid dyes, basic dyes, disperse dyes, etc.) can be used if they are fluorescent.

The overcoat layer 104 has a function of flattening the unevenness of the color filter and the color conversion layer and facilitating formation of a pattern having an organic EL light emitting function thereon.
Examples of the material for the overcoat layer 104 include acrylic resins, novolac resins, and polyimide resins.

  The organic EL element of the present invention is formed by sequentially forming a passivation layer 105, a first electrode (transparent electrode) 106, an organic EL layer 109, and a second electrode 110 on the overcoat layer 104. Yes.

The passivation layer 105 is a layer having a function of blocking moisture and volatile substances contained in the color conversion layer and the overcoat layer so as not to adversely affect the organic EL light emitting layer.
For example, SiN, SiON, SiO2, or a laminate thereof is preferably used as the material of the passivation layer 105.

  The first electrode 106 is a film made of a light-transmitting conductive material, and for example, In-Tin oxide (ITO), In-Zn oxide (IZO), or the like is preferably used.

The organic EL layer 109 can be composed of a hole injection layer, a hole transport layer, an organic light emitting layer, an electron transport layer, and an electron injection layer. However, the structure is not particularly limited, and the first electrode 106 and the first electrode 106 Any structure that includes at least an organic light emitting layer that emits light by recombination of holes and electrons generated by applying a voltage to the two electrodes 110 may be used. Specifically, the organic EL layer 109 has the following structure, for example.
(1) Organic light emitting layer (2) Hole injection layer / organic light emitting layer (3) Organic light emitting layer / electron transport layer (4) Hole injection layer / organic light emitting layer / electron transport layer (5) Hole injection layer / Hole transport layer / organic light emitting layer / electron transport layer (6) hole injection layer / hole transport layer / organic light emitting layer / electron transport layer / electron injection layer

The material of each layer in the organic EL layer 109 is not particularly limited, and known materials can be used. The material of the organic light emitting layer can be selected according to the desired color tone. For example, in order to obtain light emission from blue to blue green, fluorescent whitening such as benzothiazole, benzimidazole, and benzoxazole Agents, metal chelated oxonium compounds, styrylbenzene compounds, aromatic dimethylidin compounds, and the like can be used.
Materials for the electron injection layer include alkali metals such as Li, Na, K, or Cs; alkaline earth metals such as Ba and SI; rare metals; or their fluorides, aluminum chelates (Alq), etc. However, the present invention is not limited to these. Furthermore, Alq3 and benzazul can be used as the material for the electron transport layer, but the material is not limited to these.
As the hole injection layer, copper phthalocyanine can be used, but is not limited thereto. As the hole transport layer, 4,4′-bis [N- (l-naphthyl) -N-phenylamino] biphenyl, triphenyldiamine (TPD), or the like can be used, but is not limited thereto. It is not a thing.

The second electrode 110 is formed directly on the surface of the organic EL layer 109 opposite to the first electrode 106 or via the protective film. The second electrode 110 is preferably made of a conductive and reflective material such as Al, Ag, Mg / Ag.
Hereinafter, although the present invention is explained based on an example, the present invention is not limited to this.

  A black matrix (CK-7001: manufactured by FUJIFILM ARCH) having a thickness of 1 μm was formed on a non-alkali glass substrate having a size of 230 × 200 mm × 0.7 mm in thickness by a photolithographic method. The pixel size (RGB) is □ 150 μm (169 ppi), the aperture is 20 μm × 120 μm (line width of about 30 μm) × RGB, and the aperture ratio is 32%. Next, a red color filter (CR-7001: manufactured by FUJIFILM ARCH), a green color filter (CG-7001: manufactured by FUJIFILM ARCH), and a blue color filter (CB-7001: manufactured by FUJIFILM ARCH) are photolithographed. Formed by the law. The thickness was 1 to 2 μm, and an island shape of about 40 μm × 140 μm × RGB was arranged. Therefore, the end of the color filter is 10 μm on one side of the black matrix, and the distance from the adjacent is 10 μm. A 50 nm-thick Al film was formed thereon by sputtering. The sputtering apparatus used was an RF-planar magnetron and the gas used was Ar. The substrate temperature during the formation was about 100 ° C. A resist was applied thereto, and a horizontal reflective film made of Al having a line width of 26 μm (about 2 μm inside from one side of the black matrix) and a thickness of 50 nm was formed by exposure and development.

  Next, using the same photomask as the color filter, a color conversion layer of 40 μm × 140 μm × RGB and a thickness of about 10 μm was formed so as to be arranged in an island shape as shown in FIG. Therefore, the end portion of the color conversion layer was also covered with the black matrix at 10 μm on one side, and the distance from the adjacent was aimed at 10 μm. However, since the color conversion layer is thick, it is difficult to control the line width, and the actual interval is about 4 to 16 μm. As for the coating solution, 0.05 g of coumarin 6 is added for conversion to green and 25 g of rhodamine B + coumarin for conversion to red with respect to 25 g of photoresist V259PAP5 (manufactured by Nippon Steel Chemical Co., Ltd.). 05 g was added. In addition, since the emission spectrum of the organic EL element described later is blue to green (400 nm to 550 nm), blue was not formed as a color conversion layer, but was formed of a transparent acrylic resin.

  Then, an Al film having a thickness of about 50 nm was formed by sputtering and formed by photolithography as shown in FIGS. 3B and 5B. At this time, in order to reduce the cost, the same photomask as that for the horizontal reflection film was used, and the line width was narrower than that of the horizontal reflection film by adjusting the exposure time and etching time of the resist (the opening was larger by about 3 μm or more on one side). . Therefore, the color conversion layer opening area> the horizontal reflection film opening area> the black matrix opening area.

On top of this, an acrylic resin was spin-coated with a thickness of about 3 μm, exposed and developed to be flattened. This was heated at 180 ° C. for 30 minutes to remove moisture, and then a SiO ₂ gas barrier layer having a thickness of about 200 nm was formed by sputtering. The sputtering apparatus used was an RF-planar magnetron and the gas used was Ar. The substrate temperature at the time of formation was 80 ° C.

An IZO film having a thickness of about 200 nm is formed on the underlayer produced as described above by sputtering, and a resist agent “OFRP-800” (trade name, manufactured by Tokyo Ohka Kogyo Co., Ltd.) is applied on the IZO, followed by photolithography. Striped patterns were formed by the method, and anodes corresponding to the light emitting portions (red, green, and blue) of the respective colors were obtained. The side taper angle of the IZO pattern adjusts the exposure time and etching conditions,
The angle was about 40 ° with respect to the lamination surface of the passivation layer. Next, a 1 μm novolak resin film (JEM-700R2, manufactured by JSR) was applied thereon by spin coating, and a shadow mask was formed so as to open a window at a portion (display portion) that emits light by a photolithographic method. The display portion mask opening was about 26 μm × 126 μm.

  Next, a cathode separation wall was arranged in a direction perpendicular to the IZO in the gap between the openings of the shadow mask to make a matrix drive structure. The cathode separation wall is an organic resist material, and the exposure time was adjusted so that the upper surface was approximately 12 μm wide, the bottom surface was approximately 6 μm wide, and the height was approximately 4 μm.

Next, after the substrate is subjected to UV ozone treatment for about 5 minutes, it is mounted in a resistance heating vapor deposition apparatus, and the hole injection layer, hole transport layer, organic light emitting layer, and electron injection layer are sequentially formed without breaking the vacuum. A film was formed. During film formation, the internal pressure of the vacuum chamber was reduced to 1 × 10 ⁻⁴ Pa. As the hole injection layer, copper phthalocyanine (CuPc) was laminated to a thickness of 100 nm. As the hole transport layer, 4,4′-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (α-NPD) was laminated to a thickness of 20 nm. The light emitting layer was formed by laminating 30 nm of 4,4′-bis (2,2′-diphenylvinyl) biphenyl (DPVBi). The electron injection layer was formed by laminating 20 nm of aluminum chelate (Alq). During film formation, a metal mask having a square window opened at a position corresponding to the display portion was applied.

  Thereafter, an A1 electrode having a thickness of 200 nm was formed without breaking the vacuum so that a stripe pattern perpendicular to the anode (IZO) line was obtained using the cathode separation wall. At that time, a metal mask having a square window at a position corresponding to the display portion was applied.

Next, the organic EL substrate was moved to a bonding apparatus having 5 ppm oxygen and 5 ppm water. Inside the laminating apparatus, set a non-alkali glass with counterbore (position facing the back of the display part) of 230 x 200 mm x 0.7 mm thick, which has been previously washed with acetone and vacuum heated and dried at 200 ° C for 5 minutes. Then, a desiccant was pasted on the counterbore part, and an epoxy ultraviolet curing adhesive was applied to the counterbore outer peripheral adhesive part with a dispenser, and then the pressure was reduced to about 90 kPa for pasting. Then, after putting into a heating furnace and heating at 80 ° C. for 1 hour, it was naturally cooled in the furnace for 30 minutes and taken out. Finally, it was divided into individual panels by an automatic glass scribe device and an automatic break device.
In this panel, the luminance was improved by about 10 to 20% as compared with the case where the reflective film on the back surface of the black matrix and the side surface of the color conversion layer was not provided.

  A black matrix (CK-7001: manufactured by FUJIFILM ARCH) having a thickness of 1 μm was formed on a non-alkali glass substrate having a size of 230 × 200 mm × 0.7 mm in thickness by a photolithographic method. The pixel size (RGB) is □ 150 μm (169 ppi), the aperture is 20 μm × 120 μm (line width of about 30 μm) × RGB, and the aperture ratio is 32%. A 50 nm-thick Al film was formed thereon by sputtering. The sputtering apparatus used was an RF one-plane magnetron, and the gas used was Ar. The substrate temperature during the formation was about 100 ° C. A resist was applied thereto, and a horizontal reflective film having a line width of 26 μm (about 2 μm inside from one side of the black matrix) was formed by exposure and development.

  Next, a red color filter (CR-7001: manufactured by FUJIFILM ARCH), a green color filter (CG-7001: manufactured by FUJIFILM ARCH), and a blue color filter (CB-7001: manufactured by FUJIFILM ARCH) are photolithographed. Formed by the law. The thickness was 1 to 2 μm, and an island shape of about 40 μm × 140 μm × RGB was arranged. Therefore, the end of the color filter is 10 μm on one side of the black matrix, and the distance from the adjacent is 10 μm.

  Next, using the same photomask as the color filter, a color conversion layer of 40 μm × 140 μm × RGB and a thickness of about 10 μm was formed so as to be arranged in an island shape as in Example 1. Therefore, the end portion of the color conversion layer was also covered with the black matrix at 10 μm on one side, and the distance from the adjacent was aimed at 10 μm. However, since the color conversion layer is thick, it is difficult to control the line width, and the actual interval is about 4 to 16 μm. The coating solution is 0.05 g of coumarin 6 for conversion to green and 25 g of rhodamine B + coumarin 60 for conversion to red, with respect to 25 g of photoresist V259PAP5 (manufactured by Nippon Steel Chemical Co., Ltd.). .05 g was added. In addition, since the emission spectrum of the organic EL element to be described later is blue to green (400 nm to 550 nm), blue was not used as a color conversion layer, but was formed as a clear layer using a transparent acrylic resin.

  Then, an Al film having a thickness of about 50 nm was formed by sputtering and formed by photolithography as shown in FIGS. 4B and 5B. At this time, in order to reduce the cost, the same photomask as that for the horizontal reflection film was used, and the line width was narrower than that of the horizontal reflection film by adjusting the exposure time and etching time of the resist (the opening was larger by about 3 μm or more on one side). . Therefore, the opening area of the color conversion layer side surface reflection film> the horizontal reflection film opening area> the black matrix opening area.

  The subsequent manufacturing steps are the same as those in the first embodiment. In this panel, the luminance was improved by about 10% as compared with the case where the reflective film on the back surface of the black matrix and the side surface of the color conversion layer was not provided.

FIG. 1A is a schematic cross-sectional view of a light emission unit of a color conversion type organic EL element in the case of producing a conventional low-definition panel, and FIG. 1B creates a high-definition panel without changing rules. It is typical sectional drawing of the light emission unit of the color conversion system organic EL element in the case of having carried out. FIG. 2 is a perspective view showing the shape and arrangement of a conventional color filter and color conversion layer. FIG. 3A is a schematic cross-sectional view of the organic EL device of the present invention in which a reflective film is formed between the color filter and the color conversion layer, and FIG. 3B further reflects on the side surface of the color conversion layer. It is typical sectional drawing of the organic EL element of this invention which formed the film | membrane. FIG. 4A is a schematic cross-sectional view of the organic EL element of the present invention in which a reflective film is formed between the color filter and the black matrix, and FIG. 4B further shows a reflective film on the side surface of the color conversion layer. It is typical sectional drawing of the organic EL element of this invention which formed A. 5A is a perspective view showing the shape and arrangement of the color filter / color conversion layer laminate in FIGS. 3 and 4, and FIG. 5B is a perspective view of FIGS. 3B and 4B. It is a typical perspective view which shows the general appearance of 1 pixel of the organic EL element of this invention shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Light emission unit 101 Black matrix 102 Color filter 103 Color conversion layer 104 Overcoat layer (flattening layer)
105 Passivation layer 106 First electrode (transparent electrode, anode)
107 taper 108 shadow mask (insulating film)
109 Organic EL layer 110 Second electrode (reflection electrode, cathode wiring)
11 Substrate 21 Black matrix layer 22 Open window 23 Color filter / color conversion layer laminate (color conversion layer of the same pattern is laminated on the color filter)
31, 41 Horizontal reflective film (reflective film that reflects part of the light absorbed by the black matrix)
32, 42 Side reflection film (reflection film formed on the side surface of the color conversion layer)
51 Color filter layer / color conversion layer laminate for each light emitting unit

Claims (8)

One or more in which a black matrix, a color filter, a color conversion layer or a clear layer, an overcoat layer, a first electrode, an organic EL layer including an organic light emitting layer, and a second electrode are sequentially formed on the substrate. A bottom-emission type organic EL element of a color conversion type in which light generated from the organic EL layer is emitted from the substrate,
An organic EL device comprising a reflective film so as to reflect a part of the light that passes through a color conversion layer or a clear layer and is absorbed by a black matrix and takes it out of the substrate.   The organic EL element according to claim 1, further comprising a reflective film between the color conversion layer or the clear layer and the color filter within a light shielding range of a black matrix.   The organic EL element according to claim 1, further comprising a reflective film between the color filter and the black matrix within a light shielding range of the black matrix.   4. The reflective film according to claim 1, wherein the reflective film is parallel to the organic EL layer at least between the color conversion layer or the clear layer and the color filter, or between the color filter and the black matrix. The organic EL element of description.   5. The organic EL device according to claim 1, comprising two or more light emitting units, and further comprising a reflective film on a side surface of the color conversion layer or the clear layer in the adjacent light emitting units.   6. The light emitting device according to claim 5, further comprising two or more light emitting units, wherein the color conversion layer or the clear layer is provided separately for each light emitting unit, and a reflective film is provided on the entire side surface of each color conversion layer or the clear layer. Organic EL element. For each light emitting unit,
The organic EL element according to claim 1, wherein the horizontal reflection film opening area (B) is larger than the black matrix opening area (A). A black matrix layer, a color filter layer, a color conversion layer or a clear layer, an overcoat layer, a first electrode, an organic EL layer including an organic light emitting layer, and a second electrode are sequentially formed on the substrate. A method for producing a bottom emission type organic EL element of a color conversion method comprising at least one light emitting unit, wherein light generated from an organic EL layer is emitted from the substrate,
Forming a black matrix layer on the substrate so as to form an opening window through which the light can be emitted;
A step of forming a color filter layer so as to cover the opening window by a photolithographic method;
Forming a reflective film on the color filter layer so as not to block the light perpendicularly incident on the aperture window;
Forming a color conversion layer divided for each light emitting unit on the color filter layer and the reflective film using a photomask used for forming the color filter layer. Manufacturing method of organic EL element.

Images