JP2005322490A - Method for manufacturing electroluminescence display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing an EL display device which can improve the extraction efficiency of guided light and is excellent in workability of EL elements (pixel constituent materials).

A thin layer substrate 1 having two light-transmitting resin layers 11 and 12 having different refractive indexes and a physical effect of causing disturbance in the reflection / transmission angle of light at the interface between both layers of the substrate 1. A method for manufacturing an EL display device in which a concavo-convex region 13 is formed, and two light-transmitting resins having different refractive indexes in a state of being temporarily fixed using a release sheet 51 when the thin-layer substrate 1 is manufactured. The surface of one of the layers 11, 12 is transferred by a replica method to form the uneven region 13, and the surface of the uneven region 13 is made flat with the other translucent resin layer 12. An EL display device comprising: a covering step, wherein the thin layer substrate 1 is peeled off from the release sheet 51 after or before the formation of the pixel constituent material including the electrode and the light emitting layer on the thin layer substrate 1. Production method.

[Selection] Figure 2

Description

The present invention relates to a method of manufacturing an EL display device using an electroluminescence (hereinafter referred to as EL) element, particularly an organic EL element, and applied to, for example, a backlight light source of a liquid crystal display device.

An EL element that provides a light emitting layer between electrodes to obtain light emission is not only used as a display device, but also various types of devices such as flat illumination, optical fiber light source, liquid crystal display backlight, and liquid crystal projector backlight. As a light source, research and development is actively progressing. In particular, the organic EL element is excellent in terms of light emission efficiency, low voltage driving, light weight, and low cost, and has attracted much attention in recent years.

However, in an in-solid light-emitting device that extracts light from the light-emitting layer itself, such as an organic EL device, emitted light having a critical angle determined by the refractive index of the light-emitting layer and the refractive index of the emission medium is totally reflected and confined inside. , Lost as guided light.

In the calculation based on the classical law of refraction (Snell's law), assuming that the refractive index of the light emitting layer is n, the light extraction efficiency η for extracting the generated light to the outside is approximated by η = 1 / 2n ² . If the refractive index of the light emitting layer is 1.7, η = about 17%, and 80% or more of the light is lost as guided light and lost in the side face direction of the device.

In order to extract guided light to the outside, a region that disturbs the reflection / transmission angle of light is formed between the light-emitting layer and the emission surface, breaking Snell's law, and being totally reflected as originally guided light It is necessary to change the transmission angle. Many methods have been proposed for improving the extraction efficiency by providing the EL element with such a region that disturbs the reflection / transmission angle.

For example, the substrate surface is provided with a concavo-convex structure (Japanese Patent Laid-Open No. 9-63767), the light extraction side of the substrate is a lens structure (Japanese Patent Laid-Open No. 9-171892), and the EL element itself has a three-dimensional structure or an inclined surface. In which EL is formed (Japanese Patent Laid-Open No. 11-214163), in which a diffraction grating is formed in an EL element (Japanese Patent Laid-Open No. 11-283751), and the like are disclosed. In addition, many attempts have been made to take out guided light confined inside the device by physically changing the shape of the substrate.

Through these efforts, the guided light confined in the organic EL element can be extracted to some extent. In particular, when the organic EL element is applied to a planar illumination application having a large light emitting area, the above proposal can be suitably applied.

However, in the case of a display device using an organic EL element, that is, a display device, a method for extracting guided light becomes extremely difficult. For example, taking an example of a liquid crystal display device that has been rapidly developed in recent years, higher definition has progressed year by year, and the size of one side of one pixel has been reduced to 0.3 mm or less. As described above, there are some problems in taking out the guided light of the organic EL display device and increasing the light emission efficiency.

For example, as shown in FIG. 6, when a concavo-convex structure region 103 for extracting guided light is formed on the surface of a glass substrate 101 in which a plurality of pixels are formed as a light-emitting layer 102, the thickness depends on the thickness of the glass substrate 101. Due to the influence of the parallax, the guided light is extracted at a position deviated from the actual pixel portion, and as a result, the display image is blurred or blurred. In order to solve this crosstalk, as shown in FIG. 7, if the distance between the light emitting layer 102 and the concavo-convex structure region 103 is made sufficiently small with respect to the pixel size, it can be easily solved on the paper surface. It seems to be.

Further, for the purpose of preventing such crosstalk, a configuration is disclosed in which the thickness of the transparent substrate is approximately 0.2 mm or less and a light scattering layer is formed on the surface thereof (Japanese Patent Laid-Open No. 2002-43054). Publication). Furthermore, in order to prevent the above-mentioned crosstalk, a configuration in which the uneven structure region 103 is formed near the light emitting layer 102 and the unevenness is 0.6 μm or less is disclosed (Japanese Patent Laid-Open No. 2003-207572). Publication).

Further, as shown in FIG. 8, even if light passes through the concavo-convex region 103 once, the light whose transmission angle is equal to or larger than the critical angle of the substrate surface, as shown in FIG. The surface is totally reflected and returned to the uneven structure region 103 again.

At this time, as a result of being refracted and scattered by the region 103 of the concavo-convex structure, light that has broken the critical angle condition is emitted to the outside. That is, the amount of light to be extracted increases, but this light is emitted at a location different from the pixel that actually emits light, and eventually causes crosstalk. That is, specifically, the state is such that the display is viewed in a deep fog as a whole.

As a completely different approach, a configuration is disclosed in which a region where the refractive index can be regarded as 1.0, such as almost air, is provided between the transparent electrode and the substrate, such as an inert gas or silica airgel. (See Patent Documents 1 to 3).

In this organic EL element, since the total thickness of indium tin oxide (ITO) used exclusively as the light emitting layer and the transparent electrode is about 200 nm, the thickness is less than that in which the waveguide mode is established. When an ultra-low refractive index layer is provided, light originally confined as guided light leaks into the ultra-low refractive index layer, and once leaked into the layer with a refractive index of 1.0, the light is externally received without being totally reflected. This is a phenomenon that the light is emitted. In this case, it is not necessary to provide a physically uneven surface, and crosstalk due to parallax, which has been a problem as described above, does not occur, which is an effective method for improving luminance for display applications.

However, the biggest problems of the organic EL element configured as described above are ensuring mechanical strength, ensuring surface smoothness, and patterning of ITO electrodes and the like. For example, when silica airgel is used, vacancies can be introduced up to a refractive index almost equal to that of air, but its mechanical strength cannot be said to be practical.

In addition, since it is composed of a porous film, there are many practical problems such as absorbing water during wet etching and losing its original function in the photolithography process for patterning the ITO electrode. It is.

In order to solve these problems, a region formed for extracting guided light, that is, a region 103 that causes disturbance in the reflection / transmission angle of light is selected to have a structure sufficiently smaller than the size of the light emitting pixel, and the light emitting layer 102 is selected. It is necessary to make the distance from the region 103 sufficiently close to the size of the light emitting pixel, and to make a low refractive index layer such as an air layer on the surface.

In order to realize such a structure, the organic EL element needs to be formed on an extremely thin substrate due to the above-described restrictions, and the reflection / transmission angle of light is disturbed in the extremely thin substrate. It is necessary to create an area.

However, the manufacture of an organic EL display device requires a number of processes such as electrode film formation, cleaning, patterning, organic layer film formation, and sealing. With such a very thin substrate, the EL display device can be efficiently manufactured. The current situation is that it is difficult to manufacture.
JP 2001-196164 A JP 2001-202827 A JP 2004-22182 A

In light of such circumstances, the present invention provides an EL display device that can efficiently extract a guided light component confined inside an EL element without impairing image characteristics and visibility, and has excellent luminous efficiency. It is an object of the present invention to provide a method for manufacturing an EL display device that can easily perform various kinds of processing on a necessary very thin substrate and has excellent workability.

As a result of intensive studies to solve the above problems, the present inventors have reflected light emitted in a state where a thin layer substrate composed of two translucent resin layers having different refractive indexes is held by a release sheet. -It has been found that good results can be obtained with respect to the above-mentioned problems by forming a physically uneven region that causes disturbance in the transmission angle, and the present invention has been completed.

That is, according to the present invention, when an EL element that extracts planar light emission from a light emitting layer through an electrode is divided and arranged in a plurality of pixels, and the diagonal dimension of one pixel is d, the thickness is d / 5 or less. It has a set thin layer substrate, this substrate has two translucent resin layers with different refractive indexes, and physical irregularities that cause disturbance in the reflection / transmission angle of the emitted light at the interface of both layers Of the two light-transmitting resin layers having different refractive indices in a state of being temporarily fixed using a release sheet in the production of the thin layer substrate. The thin layer substrate includes a step of transferring the surface of one of the first and second surfaces by a replica method to form the uneven region and covering the surface of the uneven region with the other translucent resin layer in a flat shape. After or before the formation of the pixel component including the electrode and the light emitting layer, Those of the manufacturing method of an EL display device, which comprises separating the substrate from the release sheet.

In particular, the present invention provides a method for manufacturing an EL display device having the above-described configuration in which the thickness of the thin-layer substrate is set to d / 10 or less, and a method for manufacturing an EL display device having the above-described configuration in which the release sheet is a thermal release sheet. And an EL display device having the above-described configuration, in which the thin substrate is a first substrate, and the second substrate is provided on the first substrate through a low refractive index layer having optical properties substantially equivalent to those of the air layer. Each of the manufacturing methods can be provided.

In the method for manufacturing an EL display device of the present invention, the EL element is formed using a release sheet, so that the supporting thin layer substrate can be handled easily and handled. That is, in order to obtain a display device with high image characteristics and high visibility, when an EL element is formed on an extremely thin substrate, it becomes difficult to handle the substrate. The formation process becomes easy, and as a result, the light extraction efficiency and the visibility can be improved, and the productivity and the yield can be improved.

Embodiments of the present invention will be described below based on the drawings.
First, FIG. 1 is a schematic configuration diagram showing an organic EL display device to which a manufacturing method according to an embodiment of the present invention is applied.

This organic EL display device includes a first substrate (thin layer substrate) 1 having a transparent electrode 2 as an anode, a light emitting layer 3 formed on one side of the substrate 1, and a cathode laminated on the light emitting layer 3. As a reflection electrode (metal electrode) 4, a low refractive index layer 5 substantially equivalent to an air layer disposed on the other side of the substrate 1, and a second substrate 6 bonded to the low refractive index layer 5. And.

In addition to the transparent electrode 2, the substrate 1 is interposed between the low refractive index layer 11, the high refractive index layer 12, and the low refractive index layer 11 and the high refractive index layer 12. It has a multi-layer structure including a concavo-convex structure region 13 that causes disturbance. The light emitting layer 3 together with the reflective electrode 4 constitutes a plurality of divided pixels P in the organic EL element. In this figure, four pixels are shown, and d represents a diagonal dimension per pixel.

The diagonal dimension is, for example, √2 × 300 μm≈424 μm when the pixel size is 300 μm × 300 μm. If the pixel is not rectangular, the maximum length in the pixel can be considered as d. The pixel size is appropriately selected depending on the resolution and application of the EL display device, and the patterning and formation can be performed by an existing manufacturing method.

In the first substrate 1, a region 13 that is a physically uneven surface is provided at the interface between the high refractive index layer 12 and the low refractive index layer 11. What is important here is the first substrate 1. The thickness t is designed to be 1/5 or less, preferably 1/10 or less of the diagonal dimension d of the pixel P, and the region 13 in which the reflection / transmission angle of light is disturbed is formed within the thickness t. It is.

When the thickness t is greater than d / 5, the propagation distance in the lateral direction becomes longer when the guided light is multiple-reflected, and the opportunity for the guided light to be emitted to the low refractive index layer 5 substantially equal to the air layer is reduced. In addition, it propagates without attenuation to the adjacent pixel region, causing crosstalk.

In order to further reduce crosstalk and obtain a sharp image, the thickness t of the first substrate 1 is more preferably d / 20 or less, and further preferably d / 40 or less. Although it depends on the pixel size d, if it is too thin, it is difficult to ensure mechanical strength.

By the way, with the recent high definition, for example, the pixel size of the liquid crystal display device has been reduced to a pixel size of 200 μm or less on one side in a high definition device. For example, assuming that the diagonal dimension of the pixel is 200 μm, the thickness of the first substrate 1 in the present invention is 40 μm or less, preferably 20 μm or less.

In such a case, if the first substrate 1 is formed of a resin film, it becomes very difficult to handle. In addition, this extremely thin resin film has a laminated structure of the high refractive index layer 12 and the low refractive index layer 11, and a physical uneven surface is provided as an area 13 in which the reflection / transmission angle of light is disturbed at the interface. There is a need.

The existing method can be used for the region 13 having the concavo-convex surface without any particular limitation. However, in consideration of productivity and cost, a mold having a concavo-convex structure formed in advance is used, and the region is formed by a replica method. The transfer method is most preferable.

In this case, a resin varnish melted or dissolved in a solvent may be applied on the mold, solidified and then peeled off. However, it is not easy to peel an extremely thin resin film from the mold as described above.

It has been found that the EL display device manufacturing method according to the present invention is effective for this problem. Hereinafter, this manufacturing method will be described with reference to FIGS. Here, a case where the thickness of the first substrate 1 is 20 μm is taken as an example.

First, as shown in FIG. 2A, a resin varnish that becomes the low refractive index layer 11 is applied to the prepared mold M so that the film thickness after solidification becomes, for example, 10 μm. After the resin is solidified by a predetermined treatment, a release sheet 51 is attached to the surface as shown in FIG. As the release sheet 51, a sheet having a thickness sufficient for normal handling can be used.

Next, as shown in FIG. 2 (C), after the low refractive index layer 11 is peeled from the mold M, both the release sheet 51 and the uneven structure region 13 are transferred as shown in FIG. 2 (D). A resin varnish to be the high refractive index layer 12 is applied to the low refractive index layer 11 so that the film thickness after solidification is 10 μm, and the surface of the region 13 is covered flatly, and a predetermined treatment is performed. Solidify by applying. The first substrate 1 is formed through such steps.

Thereafter, as shown in FIG. 3A, ITO is deposited on the surface of the high refractive index layer 12 as the transparent electrode 2 and patterned so as to obtain a predetermined pixel size by a photolithography process or the like. Next, as shown in FIG. 3B, an insulating layer between the pixels and the cathode separator 52 are formed by using a photoresist or the like using a photolithography process, and then, as shown in FIG. The organic EL layer 3) and the cathode 4 are formed by vacuum deposition.

The thicknesses of the transparent electrode (ITO layer) 2, the light emitting layer (organic EL layer) 3 and the cathode 4 formed here are about 100 nm at most, and the thicknesses of the high refractive index layer 12 and the low refractive index layer 11 are as follows. It is so thin that it can be ignored.

Next, as shown in FIG. 4B, a sealing resin 53 such as an ultraviolet curable epoxy resin is dropped on the surface of the cathode 4, and a cover glass 54 is placed thereon, and then the resin is cured. . Then, after giving a predetermined process, as shown to FIG. 5 (A), the peeling sheet 51 is peeled. Finally, as shown in FIG. 5B, the second layer is interposed via the spacer 55 so that the air layer 5 exists between the low refractive index layer 11 of the first substrate 1 and the second substrate 6. By installing the substrate 6, the organic EL display device having the above configuration can be manufactured.

In the description of FIG. 2 to FIG. 5 described above, the low refractive index layer 11 obtained by applying the translucent resin varnish constituting the low refractive index layer 11 to the mold M and transferring the concavo-convex region 13 is used. The high refractive index layer 12 is formed, temporarily fixed using the release sheet 51, and coated with a translucent resin varnish constituting the high refractive index layer 12 to cover the surface of the region 13 in a flat shape. However, the order of forming the low refractive index layer 11 and the high refractive index layer 12 may be reversed.

That is, a translucent resin varnish constituting the high refractive index layer 12 is applied to the mold M to form the high refractive index layer 12 to which the concavo-convex region 13 is transferred, and this is formed using the release sheet 51. Temporarily fixing and applying a light-transmitting resin varnish constituting the low refractive index layer 11 to form the low refractive index layer 11 covering the surface of the region 13 in a flat shape, It may be produced.

When taking the reverse aspect, after producing the first substrate 1 by the above method, the release sheet 51 is peeled to expose the high refractive index layer 12, and the transparent electrode (ITO layer) 2, A pixel constituent material composed of the light emitting layer (organic EL layer) 3 and the cathode 4 is formed and subjected to the same processing as described above such as sealing with an epoxy resin. In order not to interfere with these treatments, the air layer 5 is usually formed on the low refractive index layer 11 of the first substrate 1 produced by the above method before the release sheet 51 is released. The second substrate 6 may be installed so as to be interposed, and then the release sheet 51 may be peeled off to perform the above series of processing.

There is no limitation in particular in the kind of peeling sheet 51 used for said method, It can select suitably in consideration of the manufacturing process of an organic electroluminescence display. For example, a heat release sheet as disclosed in JP-A-6-184504 is suitable. Moreover, the type which peels by solidifying with energy rays, such as an ultraviolet-ray, may be sufficient.

The refractive index of the high refractive index layer 12 in the first substrate 1 is usually selected to be 1.5 or more, preferably 1.6 or more, and more preferably 1.7 or more. The high refractive index layer 12 is formed adjacent to the ITO layer 2 that is a transparent electrode of the organic EL element.

In general, the refractive index of the light emitting layer 3 of the organic EL element is about 1.6 to 1.75. Therefore, if the refractive index of the high refractive index layer 12 is larger than the refractive index of the light emitting layer 3, there is no total reflection occurring at the interface between the ITO layer 2 and the high refractive index layer 12, and all of the emitted light is reflected and reflected. Since it propagates to the region 13 where the transmission angle is disturbed, higher efficiency can be achieved.

If the refractive index of the light-emitting layer 3 is 1.7 and the refractive index of the high-refractive index layer 12 is 1.52, it is calculated from classical Snell's law, about 45% of the emitted light. Is totally reflected at the interface between the ITO layer 2 and the high refractive index layer 12, and can no longer be taken out by the configuration of the present invention. On the other hand, if the refractive index is too high, the confinement effect in the high refractive index layer 12 becomes too large and it becomes difficult to extract guided light.

The translucent resin material constituting the high refractive index layer 12 can be used without particular limitation as long as it is a resin material having optical transparency. Suitable resin materials include polyester, polyether, polyetherketone, polyimide, polyamide, polyimideamide, epoxy, polyurethane, polyurethane acrylate, polycarbonate, and aromatic structures such as fluorene, naphthalene, and biphenyl. A polymer resin having a relatively high refractive index into which halogen or sulfur such as chlorine or bromine is introduced, or a material having a refractive index adjusted by dispersing inorganic nanoparticles or the like in the resin can also be used.

The translucent resin material constituting the low refractive index layer 11 in the first substrate 1 can be basically used as long as it is a transparent material having a refractive index different from that of the high refractive index layer 12. A material having a lower refractive index than the high refractive index layer 12 is selected. Specific materials include polyacrylates, polyurethane acrylates, polyimides, polyamides, polyamideimides, polyurethanes, epoxies, polyolefins, polymer resins having a relatively low refractive index in which fluorine or an aliphatic skeleton is introduced into these main structures, Also, a material in which inorganic nanoparticles are dispersed in a resin to adjust the refractive index can be used.

The structure of the region 13 that causes disturbance in the reflection / transmission angle is not particularly limited, and any structure that can change the transmission angle of light is applicable. The structure of the physical concavo-convex surface is not limited at all. For example, the light transmission angle can be changed such as a pyramid structure such as a triangular pyramid or a quadrangular pyramid, a hemispherical microlens structure, a rectangular structure, or a rod-shaped structure. Any structure that can be disturbed can be applied.

In the present invention, the light is designed to take out the guided light by repeating the scattering several times instead of trying to completely control the transmission angle only by passing the light once through the uneven structure. Therefore, these concavo-convex structures do not need to be processed with high accuracy, and it is not necessary to carry out a detailed optical design unlike ordinary macro lenses. The size of the uneven structure is not particularly limited. However, if the structure is smaller than the wavelength of light, the light cannot be scattered efficiently, so it is usually preferable to provide irregularities of 0.5 μm or more.

The second substrate 6 can be used without particular limitation as long as it has optical transparency, and for example, glass, various plastic substrates, and the like are used. The thickness is also arbitrary, and may be appropriately selected in consideration of mechanical strength and weight. It is preferable to form a circularly polarizing filter for preventing external light reflection on the surface of the second substrate 6 because the contrast is improved. Moreover, it can replace with the 2nd board | substrate 6 and can provide a circularly-polarizing filter directly.

The low refractive index layer 5 substantially equivalent to the air layer has a refractive index as close as possible to the air layer, that is, 1.3 or less, preferably 1.2 or less, more preferably 1.1 or less, ideally It means the layer which is the same 1.0 as the air layer. The thickness of the low refractive index layer 5 is not particularly limited, and can be freely designed over a wide range, for example, 0.1 μm to 1 mm.

In the present invention, it is not necessary that the refractive index is continuously close to 1.0. For example, only the light emitting pixel portion has a gap 5 between the first substrate 1 and the second substrate 6. The formed non-light emitting portion may have a structure in which some ribs are formed and joined. Furthermore, as shown in FIG. 5B, a spacer 55 may be provided to provide a gap (air layer) between the first substrate 1 and the second substrate 6.

Even if the low refractive index layer 5 substantially equivalent to the air layer is discontinuous, if the area ratio is sufficiently wide, the effect of the present invention can be exhibited. Further, as disclosed in Japanese Patent Application Laid-Open No. 2001-202827, it may be formed using a nanoporous material using silica airgel or the like, and is not limited at all.

There are no particular limitations on the organic material, electrode material, layer configuration, and film thickness of each layer used in the organic EL display device of the present invention, and the prior art can be applied as it is. The organic layer may be formed by vacuum deposition of a low molecular weight material, or a high molecular weight material may be formed by a coating method or the like, and is not particularly limited.

Specific configurations include anode / light emitting layer / cathode, anode / hole transport layer / light emitting layer / electron transport layer / cathode, anode / hole transport layer / electron transport light emitting layer / cathode, etc. It is not limited. In addition, a hole injection layer may be provided at the interface of the anode 2, an electron injection layer may be provided at the interface of the cathode 4, and an electron blocking layer and a hole blocking layer for increasing recombination efficiency may be inserted. Basically, when a configuration, material, and formation method that increase luminous efficiency are selected, EL light emission with high power consumption can be obtained, and the effects of the present invention can be further enhanced.

Next, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples.

A nickel mold (surface peel-treated) in which a small pyramid structure of a square pyramid having a side of 5 μm and a height of 2 μm was formed without any gap was prepared. A UV curable resin having a refractive index of 1.51 (“UVHC1101” manufactured by Toshiba Silicone Co., Ltd.) is applied onto the above mold using an applicator, and then cured by UV curing with a high-pressure mercury lamp. A refractive index layer was formed. The thickness was 10 μm.

Next, a thermal release sheet ("Riva Alpha" manufactured by Nitto Denko Corporation, release temperature 170 ° C type, substrate thickness 100 µm) is bonded to the low refractive index layer formed on the mold using a hand roller. It was. Then, the dwarf pyramid structure was transfer-molded by the replica method by peeling the low refractive index layer from the mold together with the heat release sheet. Next, a solution in which a polyethersulfone resin (PES) having a refractive index of 1.65 is dissolved in N-methyl-2-pyrrolidone at a concentration of 20% by weight is prepared, and the above-mentioned low refractive index is obtained using an applicator. It coated so that the film thickness after a dry operation might be set to 10 micrometers on a rate layer. The solvent was removed by drying in a drying apparatus set at 90 ° C. to form a high refractive index layer made of PES, and a thin layer substrate (first substrate) was produced.

Next, on the high refractive index layer made of PES of the thin layer substrate thus produced, the thickness was measured by DC sputtering from an ITO ceramic target (In ₂ O ₃ : SnO ₂ = 90 wt%: 10 wt%). A 100 nm ITO film was formed as a transparent electrode.

A positive photoresist (“MICROPOSIT SRC-300A” manufactured by Shipley Far East Co., Ltd.) was spin-coated on the ITO film formation surface.

Using a mask of L / S = 200 μm / 50 μm, provisional drying, exposure, development, curing, etching of ITO with acid, and resist removal were performed in accordance with a predetermined photolithography process to form a striped electrode pattern.

Thereafter, a positive photoresist was spin-coated again, and exposure and development / curing were performed with a similar mask so as to be perpendicular to the stripe-shaped electrode pattern, thereby forming a resist partition for insulating pixels. Then, after sufficiently washing and ozone washing for 15 minutes using a low-pressure ultraviolet lamp, the sample was set in a vacuum deposition apparatus, and organic thin film layers were sequentially formed as follows by a vacuum deposition method.

First, as a hole injection layer, CuPc represented by the following formula (1) was formed to a thickness of 15 nm at a deposition rate of 0.3 nm / s. Next, α-NPD represented by the following formula (2) was formed to a thickness of 50 nm at a deposition rate of 0.3 nm / s as a hole transport layer. Finally, as the electron transporting light emitting layer, Alq represented by the following formula (3) was formed to a thickness of 70 nm at a deposition rate of 0.3 nm / s.

Thereafter, LiF was formed to a thickness of 1 nm at a deposition rate of 0.2 nm / s, and finally, Al was formed to a thickness of 150 nm to form a cathode electrode. After taking out from the vacuum evaporation system, a UV curable epoxy resin is dropped on the cathode electrode side, and a glass slide with a thickness of 0.7 mm is placed on it, and when the epoxy resin has spread sufficiently, a high-pressure UV lamp Was used to cure the epoxy resin and seal the device.

Finally, the heat release sheet was completely peeled off by placing it on a hot plate heated to 170 ° C. for several seconds so that the base material surface of the heat release sheet was in contact with it, and an organic EL display device was produced. Here, the temperature of 170 ° C. is higher than the glass transition temperature of the organic material used, but the thermal release sheet used in this example can be peeled almost instantaneously at 170 ° C. Was not seen at all.

When a DC voltage of 6 V was applied to the organic EL display device thus obtained, green light emission was observed at the light emitting pixel portion, and no pixel blurring or crosstalk was observed at all. Further, the front luminance was increased about 1.25 times as compared with a normal organic EL display device fabricated on a glass substrate.

In Example 1, at the time of sealing with an epoxy resin, the element was sealed using a barrier film in which silicon nitride was deposited as a moisture-proof layer on a polyethylene terephthalate (PET) film having a thickness of 75 μm instead of sly glass. . Further, after peeling off the thermal release sheet, a separately prepared glass substrate (second substrate) having a thickness of 1.1 mm and a spacer having an average particle diameter of 10 μm are arranged on the surface of the low refractive index layer. The ends were fixed with an adhesive. Except this, an organic EL display device was produced in the same manner as in Example 1.

When a DC voltage of 6 V was applied to the organic EL display device thus obtained, light emission similar to that in Example 1 was observed.

The same PES solution as in Example 1 was applied to the same nickel mold as in Example 1 so as to have a thickness of 10 μm. Next, the same heat release sheet as in Example 1 was bonded, and the PES layer was peeled off from the mold together with this heat release sheet, thereby forming a high refractive index layer obtained by transferring and molding the micropyramid structure by the replica method. On this, the same UV curable resin as in Example 1 was spin-coated so as to have a thickness of 10 μm, and then UV-cured with a high-pressure mercury lamp to form a low refractive index layer. Substrate).

Next, a PET film having a thickness of 25 μm was cut out, and an acrylic pressure-sensitive adhesive having a thickness of 25 μm with a release liner was bonded to both sides thereof, and a central portion of 30 mm × 30 mm was cut out. The release liner on one side of this PET film with adhesive was peeled off and bonded to a glass substrate (second substrate) having a thickness of 1.1 mm via the adhesive. Further, the release liner on the other surface side was peeled off, and the low-refractive index layer surface made of an ultraviolet curable resin of the first substrate supported by the thermal release sheet was bonded through the adhesive.

In this way, a sample was prepared in which the thin layer substrate (first substrate) and the glass substrate (second substrate) supported by the heat release sheet were bonded together through the air layer. Then, this sample was put on the hotplate heated at 170 degreeC, and the heat | fever peeling sheet was peeled completely. Next, in the same process as in Example 1, the organic EL element was vacuum-deposited and sealed from the ITO film formation to produce an organic EL display device.

When a DC voltage of 6 V was applied to the organic EL display device thus obtained, light emission similar to that in Example 1 was observed.

It is a schematic block diagram which shows the organic electroluminescence display to which the manufacturing method of the organic electroluminescence display which concerns on embodiment of this invention was applied. It is explanatory drawing which shows the 1st step of the manufacturing method of the organic electroluminescence display of this invention to process order (A)-(D). It is explanatory drawing which shows the 2nd step of the manufacturing method of the organic electroluminescence display of this invention to process order (A) and (B). It is explanatory drawing which shows the 3rd step of the manufacturing method of the organic electroluminescence display of this invention to process order (A) and (B). It is explanatory drawing which shows the 4th step of the manufacturing method of the organic electroluminescence display of this invention to process order (A) and (B). It is a principle explanatory view of an organic EL display device. It is another principle explanatory drawing of an organic electroluminescence display. It is another principle explanatory drawing of an organic electroluminescence display.

Explanation of symbols

1 Thin layer substrate (first substrate)
2 Transparent electrode (anode)
3 Light emitting layer (organic layer)
4 Reflective electrode (cathode)
5 Low refractive index layer having optical properties substantially equivalent to air layer 6 Second substrate 11 Low refractive index layer 12 High refractive index layer 13 Uneven region 51 Release sheet (thermal release sheet)
d Diagonal dimension of pixel P Pixel M Mold

Claims (4)

A thin layer in which an electroluminescence element that takes out planar light emission from a light emitting layer through an electrode is divided into a plurality of pixels and the diagonal dimension of one pixel is d, and the thickness thereof is set to d / 5 or less. This substrate has two light-transmitting resin layers with different refractive indexes, and is formed with physically uneven areas that cause disturbance in the reflection / transmission angle of the emitted light at the interface between the two layers. A method of manufacturing an electroluminescence display device, wherein the surface of one of two light-transmitting resin layers having different refractive indexes in a state where the thin-layer substrate is temporarily fixed using a release sheet And forming the uneven region by a replica method, and covering the surface of the uneven region with the other translucent resin layer in a flat shape, and the electrode to the thin layer substrate and Formation of pixel component including light emitting layer Or before forming method of an electroluminescent display device, which comprises peeling a thin layer substrate from the release sheet.
The method of manufacturing an electroluminescent display device according to claim 1, wherein the thickness of the thin layer substrate is set to d / 10 or less.
The method for manufacturing an electroluminescence display device according to claim 1, wherein the release sheet is a thermal release sheet.
The thin film substrate is a first substrate, and the second substrate is provided on the first substrate via a low refractive index layer having optical properties substantially equivalent to those of the air layer. The manufacturing method of the electroluminescent display apparatus of description.

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