JP4255187B2 - Manufacturing method of organic EL display device and organic EL display device manufactured by the method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention is used in, for example, a dot matrix display device, a backlight of a liquid crystal display, and the like, and is an organic thin film electroluminescent device called an organic EL element, an organic electroluminescent element, an organic electroluminescent element, an organic LED element, or the like. The present invention relates to an organic EL display device using an organic electroluminescence element (hereinafter referred to as an organic EL element) using a sense phenomenon. Specifically, a plurality of organic EL display elements are formed on the same substrate and separated. The present invention relates to a method for manufacturing an organic EL display device in which a plurality of organic EL display devices are obtained.
[0002]
[Prior art]
Conventionally, the organic EL display element 80 is configured as shown in FIG. 11, for example.
An anode layer 82 made of striped ITO (Indium Tin Oxide) provided on the glass substrate 81, an organic EL layer 83 laminated thereon, and a striped cathode layer 84 orthogonal to the anode layer 82. It is configured.
[0003]
According to the organic EL element 80 having such a configuration, light is emitted from the organic EL layer 83 sandwiched between the electrodes 82 and 84 by supplying desired power from a power source (not shown) between the pair of electrodes 82 and 84. This will be visible. In this example, since it is a dot matrix type using striped electrodes, by inputting a desired signal to the striped anode layer 82 and cathode layer 84, the organic EL layer 83 sandwiched between the electrodes. The light emission can be controlled in dot units.
[0004]
The anode layer 82 is made of nickel, gold, platinum, palladium, an alloy thereof, or tin oxide (SnO ₂ ), Metals having a large work function such as copper iodide, alloys and compounds thereof, and conductive polymers such as polypyrrole can be used, but generally ITO transparent electrode layers are often used.
The cathode layer 84 is preferably made of a material effective for electron injection, that is, a metal material having a small work function capable of improving the electron injection efficiency. Aluminum, magnesium, magnesium indium alloy, magnesium aluminum alloy, magnesium silver alloy, aluminum A lithium alloy or the like is used.
The organic EL layer 83 has a two-layer structure of a hole transport layer 83a and an organic light emitting layer 83b in this order from the anode layer 82 side. As the hole transport layer 83a, N, N′-diphenyl-N, N′-bis ( 3-methylphenyl) 1,1′-biphenyl-4,4′-diamine (hereinafter abbreviated as TPD) and tris (8-hydroxyquinolinato) aluminum (Tris (8-hydroxyquinolinato) as the organic light emitting layer 83b. ) Aluminum, hereinafter Alq ₃ Are abbreviated as).
[0005]
When the organic EL element 80 having such a configuration is driven as it is in the air, the deterioration is accelerated by moisture, heat, etc., and the light emission characteristics are deteriorated. In particular, when oxygen or moisture is present around the device, oxidation is promoted, organic materials are altered, films are peeled off, dark spots (non-light emitting parts) grow and no light is emitted, resulting in a long life. There is a problem of being short.
[0006]
In view of this, it has been proposed to seal the organic EL element so that it does not come into contact with the atmosphere. For example, an organic EL display device 90 shown in FIG. 10 includes one element substrate 81 on which an organic EL element 80 is formed, the other sealing substrate 91 disposed so as to cover the organic EL layer 83 and the like, and an organic EL layer. A sealing layer 92 provided so as to surround the organic EL element 80 by bonding and fixing both the substrates 81 and 91 so that the 83 is not exposed to the outside air, and an anode layer 82 partially drawn out from the sealing layer 92; A cathode layer 84.
In addition, as proposed in Japanese Patent Application Laid-Open No. 5-41281, it is also proposed to fill and seal between an organic EL element 80 and a sealing substrate 91 with an inert liquid containing a dehydrating agent such as synthetic zeolite in a fluorocarbon oil. Has been.
[0007]
According to the organic EL display device 90 having such a configuration, since the organic EL element 80 is not exposed to the external atmosphere, an organic EL display device having a long lifetime is provided.
[0008]
Further, when the organic EL display device 90 having such a configuration is to be produced in large quantities, it can be manufactured by a method as shown in FIGS.
One element substrate 81 on which a plurality of organic EL elements 80 are formed and the other sealing substrate 91 are bonded and fixed via a seal layer 92 provided on the inner surface of the element substrate 81, and then each adjacent organic EL display is displayed. A plurality of organic EL display devices 90 are cut and divided by pressing a cut groove 88 in the element substrate 81 and a cut groove 98a, 98b in the sealing substrate 91 between the elements 80 by a scribing device or the like. Obtainable.
[0009]
[Problems to be solved by the invention]
However, in spite of providing the cut grooves 88, 98a, 98b at predetermined positions in order to perform this cutting division, not the cut grooves, but the portions away from the cut grooves are broken, leaving uncut portions 87, 97 and cracks. 86, 96 may occur.
If there are uncut portions 87 and 97, the size becomes larger than a predetermined shape, and it becomes difficult to attach the organic EL display device 90 to another device, or a flexible printed circuit board connected to drive the organic EL display device 90 The trouble which touches and damages a flexible printed circuit board arises. In addition, if there are cracks 86 and 96, the electrode terminal at that location becomes short, causing problems such as a connection failure.
In particular, in the case of obtaining an organic EL display device having a narrow frame in which the distance from the edge of the light emitting portion of the organic EL display device 90 to the substrate edge is reduced, if there is the above-described crack or uncut portion, such a dimension is required. Due to the deterioration of accuracy, the yield of the organic EL display device was lowered, which was a problem.
[0010]
The main object of the present invention is to provide a method for manufacturing an organic EL display device that has good workability and that can obtain an accurate dimensional shape.
[0011]
[Means for Solving the Problems]
According to the first aspect of the present invention, the object is to provide a first substrate on which an organic EL element is formed, a photocurable resin layer formed so as to cover the organic EL element, and the photocurable resin. A method of manufacturing an organic EL display device having a second substrate fixedly disposed opposite to a first substrate through a layer, the electrode layer being provided on the first substrate for a plurality of organic EL display devices A step of forming an organic EL element including an organic EL layer, a step of covering one substrate surface with a liquid photocurable resin, and positively attaching the other substrate to the upper surface of the photocurable resin. A step of covering the photocurable resin so as not to be convexly deformed upward; Irradiating light from the outside of the substrate, curing a portion covering the light emitting region of the organic EL element in the photocurable resin, the photocurable resin layer not cured between the portions covering the adjacent light emitting regions Said to exist After the step of curing the photocurable resin and the above-described curing step of the photocurable resin, the first substrate or the second substrate It passes between the photocuring resin and a portion covering the light emitting region of the adjacent cured organic EL element. A cutting flaw is provided at a scheduled cutting position, and the cutting is performed by applying a pressing force from the outside of the substrate to a position opposite to or near the cutting flaw at a position to be cut of a substrate different from the substrate on which the cutting flaw is provided. And a step of cutting the substrate provided with the cut flaw at the position of the flaw, thereby dividing a plurality of organic EL display devices formed on the first substrate, thereby manufacturing the organic EL display device Is achieved.
[0012]
In the first aspect, a plurality of organic EL elements in which the organic EL elements are sealed with a sealing substrate so as not to be exposed to the external environment can be manufactured collectively. In addition, since a large number of organic EL elements are formed on a single substrate, sealing is performed, and then cutting is performed, so that mass productivity is significantly higher than when organic EL display devices are formed one by one. improves.
Furthermore, since there is an uncured photocurable resin between adjacent organic EL display devices to be cut, it can be stably cut, and defects such as chipping and cracking are less likely to occur, and the yield is increased. improves. This can reduce the overall manufacturing cost.
[0013]
In the second aspect of the present invention, the step of coating with the above-mentioned photocurable resin further comprises the step of coating the photocurable resin on the electrode formed on the surface opposite to the first substrate side of the organic EL element. This object is achieved by a method for manufacturing an organic EL display device, which is performed in contact with each other.
According to the second aspect, an organic EL display device in which the organic EL element is directly coated on the photocurable resin layer and the thickness is reduced can be manufactured with high yield.
[0014]
In another aspect of the present invention, in the organic EL element forming step, the organic EL layer and the reflective electrode layer are sequentially provided on the other polarity electrode layer provided on the first substrate. It is a step of forming a plurality of organic EL elements having a light emitting portion sandwiched between them, and the step of covering with the above-mentioned photocurable resin is a light emitting portion of each organic EL element after the organic EL element forming step. A method for producing an organic EL display device, comprising: providing a protective layer so as to cover the protective layer, and bringing the photocurable resin into contact with the protective layer.
Further, the method for manufacturing an organic EL display device, wherein the protective layer is made of an oxide or a nitride.
Alternatively, the protective layer may be formed in a vacuum device continuously after the formation of the other polarity electrode of the organic EL element by a method for manufacturing an organic EL display device or the like. The objective is achieved.
According to these aspects, since the organic EL element is covered with the protective layer, it is possible to obtain a plurality of organic EL display devices with further improved resistance to the external environment.
Further, by forming the protective layer subsequent to the electrode layer, it is possible to reduce the influence of the external environment between the time when the electrode layer is formed and the time when the protective layer is covered with the photocurable resin layer. A plurality of organic EL display devices that can prevent deterioration in characteristics of the organic EL display device due to the influence of the environment can be obtained with high yield.
[0015]
In still another aspect, the thickness of the first substrate is 0.2 mm or more, and the total thickness of the organic EL display device is 1.5 mm or less. Thus, an organic EL display device manufactured by any one of the methods for manufacturing an organic EL display device according to No. 7 can be obtained.
Thereby, it is possible to obtain a thin organic EL display device that can prevent deterioration in characteristics of the organic EL display device due to the influence of the external environment such as moisture.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to FIGS. 1 to 7.
[0017]
1 and 2 show the configuration of the first embodiment of the organic EL display device according to the present invention.
1 and 2, the organic EL display device 10 includes two glass substrates 11 and 12 disposed one above the other in parallel with each other, and a lower first glass substrate 11 in order from the lower side. The organic EL element 16 is composed of an anode layer 13, an organic EL layer 14, and a cathode layer 15, and a photocurable resin layer 17 that bonds and fixes both substrates.
[0018]
The EL element 16 is formed on the inner surface (upper surface) of the lower first glass substrate 11. The anode layer 13 is formed of an ITO transparent electrode on the inner surface of the first glass substrate, and a part of the anode layer 13 is extended to the edge of the substrate outside the photocurable resin layer 17 so that it can be connected to an external power source (not shown). Has been.
The organic EL layer 14 is laminated on the anode layer 13 and is covered with a cathode layer 15 and a photocurable resin layer 17 so as not to touch the external atmosphere.
The cathode layer 15 is laminated on the organic EL layer 14 with a low work function material such as an aluminum-lithium alloy, and a part thereof extends to the edge of the substrate outside the photocurable resin layer 17. It can be connected to an external power source (not shown). In this embodiment, the anode layer 13 and the cathode layer 15 are led out in two opposing directions.
[0019]
The upper second glass substrate 12 has a property of transmitting light having a wavelength necessary for curing the photocurable resin, and is larger than the organic EL layer 14 and smaller than the first glass substrate 11. .
The photocurable resin layer 17 is made of, for example, an ultraviolet curable resin, covers the organic EL element 16, and adheres and fixes a second glass substrate as a sealing substrate to seal the organic EL element 16 from the external atmosphere.
[0020]
The organic EL display device 10 is configured as described above. When the organic EL display device 10 is used, an external power source (not shown) is connected to the anode layer 13 and the cathode layer 15 led out from the photocurable resin to input a drive signal. By doing so, the light emitted from the organic EL layer 14 is irradiated to the outside through the first glass substrate 11 and is visually recognized.
[0021]
Next, a method for manufacturing the organic EL display device 10 will be described with reference to FIGS.
[0022]
FIG. 3 shows an organic EL element formation process and a photocurable resin coating process. First, a cleaned glass substrate 11 is prepared, and an ITO transparent electrode layer 13 serving as an anode layer having a predetermined shape corresponding to a plurality of organic EL display devices is formed. An organic EL layer 14 is formed on each of the plurality of ITO transparent electrode layers 13 by means of vapor deposition or the like using a film formation mask (not shown) provided with openings having a predetermined shape corresponding to each organic EL display device. . The organic EL layer 14 has a two-layer structure in which a hole transport layer and an organic light emitting layer are laminated in order from the ITO transparent electrode layer 13 side.
The hole transport layer has a function of easily injecting holes from the anode and a function of blocking electrons. For example, a low molecular compound such as TPD can be used. The organic light emitting layer is, for example, Alq ₃ Etc. can be used.
In addition, although an example in which the organic EL layer has a two-layer structure has been shown, an electron transport layer having a function of easily injecting electrons from the cathode is provided on the organic light emitting layer, or a hole injection layer / hole transport layer / Light emitting layer / electron transport layer, hole injection layer / hole transport layer / light emitting layer, layered structure such as hole transport layer / light emitting layer / electron transport layer, or single layer organic EL layer Or what provided the organic layer of the single layer structure through the buffer layer etc. can also be used.
[0023]
Next, the cathode layer 15 made of a metal material having a small work function such as Al—Li is formed on the organic EL layer 14 by means such as vapor deposition. Similarly to the organic EL layer 14, the cathode layer 15 has a shape corresponding to each organic EL display device 10. As a result, the plurality of organic EL elements 16 are disposed on the first glass substrate 11 as shown in FIG.
[0024]
Next, as shown in FIG. 3B, a photocurable resin adjusted to a predetermined viscosity so as to cover the plurality of organic EL elements 16 is photocured by a printing method, a spin coating method, a spray method, a dropping method, or the like. A resin layer 17 is formed.
The photocurable resin is made of a material having a property of being cured by irradiation with a light beam having a predetermined wavelength, and is generally prepared by adjusting a photopolymerizable monomer, a photopolymerizable oligomer, a photopolymerization initiator, and the like. The photocurable resin used in the present invention is preferably a resin having a small amount of volatile components such as a solvent from the viewpoint of reducing the influence on the organic EL element 16, and an acrylic resin or an epoxy resin can be suitably used. In particular, when an epoxy resin having a low water absorption was used, there was a tendency to suppress the generation or growth of dark spots. Moreover, the viscosity of 10P-1000P is suitable from a viewpoint of film formability. Furthermore, when the thickness is at least 0.1 μm or more, preferably 0.2 to 0.5 μm in the state after curing, a thin organic EL display device having practical strength can be obtained, which is preferable.
[0025]
After the photocurable resin coating process is completed, a bonding process is performed in which the second glass substrate 12 is disposed opposite to the first glass substrate 11 so as to cover the photocurable resin layer 17. At that time, as shown in FIG. 4A, the second glass substrate 12 may be bonded so as to bend downward by its own weight or the like so that the central portion of the second glass substrate 12 does not protrude upward.
It is considered that the maximum amount of deflection when the second glass substrate 12 is lifted on both sides and attached to the first glass substrate can be approximated by the following equation (1).
δ _max = P ・ l ³ / (384E ・ I) (1)
Here, P is the load applied to the second glass substrate, E · I is the product of the elastic modulus E called the bending stiffness and the moment of inertia of the cross section, l is the length of the beam, ie the width between the two sides holding the substrate It is. Further, since the cross-sectional second moment is a rectangular cross section, I = (1/12) · (b · h ³ ), B is the width of the substrate opposite to l, and h is the vertical length in the substrate cross section, that is, the thickness.
[0026]
As can be seen from the above equation, the amount of deflection increases as a large glass substrate is used. Therefore, in the present invention in which a plurality of organic EL elements 16 are formed on a single substrate, the second glass substrate 12 that is larger than the case of manufacturing each organic EL display device is used. Bonding is preferably performed by using the amount of deflection to bring the substrate into contact with the photocurable resin from the center of the most bent substrate and gradually contacting the sides.
[0027]
Thereafter, as shown in FIG. 4B, the exposure mask 20 in which the light-shielding portion 21 is formed is aligned so that light is not irradiated to the boundary portion of each organic EL element 16, that is, the portion to be cut and divided in the subsequent process. Thereafter, a curing process is performed in which light irradiation with a mercury lamp, a xenon lamp, or the like is performed through the translucent portion 22 to selectively cure the region of the photocurable resin layer 17 covering the portion corresponding to the light emitting portion of each organic EL element. carry out. By irradiating light in this way, the photocurable resin layer 17a obtained by curing each organic EL element 16 formed on the first glass substrate 11 is covered and the second glass substrate 12 is bonded and fixed.
It should be noted that a photo-curing resin layer 17 that has not been photo-cured is present in a portion that is cut and divided in a later step, and the ends of the ITO transparent electrode layer 13 and the cathode layer 15 of each organic EL element 16 are present. The portion is extended to a region where the photocurable resin layer 17 that is not photocured exists.
[0028]
Next, a cutting and dividing step of the organic EL display device is performed. First, cutting flaws for cutting and dividing are formed at positions between adjacent organic EL elements 16. The cut scratches are provided on the outer surfaces of the first glass substrate 11 and the second glass substrate 12 using a scribing device equipped with a glass cutting blade. As in the conventional example shown in FIG. 8, in the vertical and horizontal directions, the first glass substrate 11 has cut grooves 18 as cut flaws, and the second glass substrate 12 has cut grooves 19a and 19b as shown in FIG. Provided.
[0029]
Thereafter, in order to cut the positions of the kerfs 19a and 19b of the second substrate 12, the second substrate 11 is moved from the first substrate side 11 to a position corresponding to the kerfs 19a of the first substrate 11 and a position corresponding to the kerfs 19b. Apply pressure to 12 side and split. Subsequently, in order to cut the first substrate on the opposite side from the position of the kerf 18, a pressure is applied to the position corresponding to the kerf 18 of the second substrate 12 from the second substrate 12 side to the first substrate 11 side. do. When a pressing force is applied to the glass substrate, as shown in FIG. 5B, the pressure is adjusted to a predetermined pressure by a breaking device (not shown) provided with a pressure piece 25 that is relatively movable in the vertical direction. It is preferable to push and split.
[0030]
Thus, when a pressing force is applied to the position corresponding to the cutting flaw from the glass substrate on the opposite side of the glass substrate on which the cut flaw is provided, the glass substrate on the opposite side of the glass substrate in contact with the pressing force piece 25 is The crack line 26 is surely entered from the location of the cut flaw and can be divided. Therefore, by continuing this process, a plurality of organic EL display devices 10 as shown in FIG. 1 can be obtained in large quantities.
[0031]
According to such a manufacturing method, for example, when a cutting and dividing step is performed by a conventional method using a glass substrate having a thickness of about 1 mm, defects such as cracks and chips are about 1%, and the sealing layer In the case of narrowing the frame by cutting the very vicinity of 92, there was a problem with a probability of about 2% or more, but in the case of the manufacturing method of the above-described embodiment, the probability is almost half or less. Met.
This is because the photocurable resin layer 17 exists between the glass substrates 11 and 12 in the cutting and dividing step in the present invention at the location where the cutting and dividing is performed. Therefore, unlike the conventional case where the state between the substrates of the region to be cut is the atmosphere, the region where the cured photocurable resin layer 17a covering the organic EL display element 16 is present is cut. The pressure difference when pressing between the areas to be divided is reduced. As a result, the stress difference and the like are reduced, thereby causing a crack in a portion other than the location where the cut flaw is provided, without causing a defect caused by the cutting division process such as a remaining crack or a chip, and the desired difference. It is estimated that the cutting can be stably performed at the cut flaw forming portion, and the occurrence of the above problems is reduced.
[0032]
In addition, when the cut scratch is provided, the photo-curable resin layer 17 is present on almost the entire surface between the first glass substrate 11 and the second glass substrate 12, so that the scratch can be reliably made with high dimensional accuracy. Accordingly, it is possible to greatly reduce the deterioration of dimensional accuracy, the cutting division failure, etc., which are likely to occur particularly when a thin glass substrate is used. Thereby, an organic EL display device can be obtained with high dimensional accuracy and high yield.
Therefore, for example, in the case of obtaining an extremely thin organic EL display device having a total thickness of less than about 1.5 mm using a substrate having a thickness of 0.2 to 0.7 mm, the present invention is particularly effective and the yield is high. This was suitable for manufacturing a thin organic EL display device that would easily deteriorate.
[0033]
Further, in the conventional manufacturing method, it is necessary to provide a seal layer between the distance from the end of the light emitting display portion of the organic EL display device to the end of the second glass substrate covering the organic EL element. Therefore, in order to obtain a display device with a narrow frame with a reduced distance, it is necessary to narrow the seal width to cope with narrowing the frame, but it is difficult to form a narrow seal width, and the seal width is reduced. Since narrowing results in a decrease in sealing performance, it has been difficult to obtain an organic EL display device with a narrow frame. However, according to the manufacturing method of the present invention, since it is not necessary to provide a separate sealing layer, the substrate end can be narrowed to a position very close to the light emitting portion of the organic EL element. Thereby, for example, the organic EL display device 10 having a very narrow frame with only an electrode terminal lead portion of about 1 mm for terminal connection can be obtained with a high yield. Therefore, it is possible to reduce the size of a device using this, and at the same time, it is possible to increase the number of organic EL display devices that can be obtained from the same substrate, and to reduce the cost as a whole.
[0034]
Next, a second embodiment will be described with reference to FIG. Since the organic EL element 16 is formed on the first glass substrate 11 in the same process as that of the first embodiment up to the organic EL element forming process and the photocurable resin coating process, description thereof is omitted here. .
[0035]
In the next second substrate bonding step and curing step, in the first embodiment, the photocurable resin layer is cured by irradiating light through the exposure mask 20, but in the second embodiment, Performs the bonding process using the second glass substrate 30 provided with the light-shielding film 31 in the area to be cut in the subsequent cutting and dividing process of the organic EL display device, and does not use the exposure mask 20 during the curing process. .
The second glass substrate 30 is prepared by forming a metal light-shielding film 31 having an opening 32 having a predetermined pattern of Al, Ti, W, Mo or the like on the inner surface or outer surface thereof by performing a photolithography process. While the second glass substrate 30 is aligned so that the portion where the light shielding film 31 is formed is positioned between the adjacent organic EL elements 16, the central portion of the substrate is bent downward as in the first embodiment. The first glass substrate 11 is bonded through the ultraviolet curable resin 17 as it is.
[0036]
Thereafter, light irradiation is performed from the side of the second glass substrate 30 provided with the light shielding film to cure the portion of the organic EL element 16 of the photocurable resin layer 17. Subsequently, as shown in FIG. 6A, the first glass substrate 11 is provided with the kerfs 18 and the second glass substrate 30 is provided with the kerfs 39a and 39b. In the same manner as described above, a plurality of organic EL display devices are obtained by applying a pressing force and cutting and dividing.
[0037]
In addition, as shown in FIG.6 (b), the small opening part 31a is provided in the light shielding film 31 of the 2nd glass substrate 30, and photocurable resin hardens | cures also in this position, and it is small wall shape or columnar shape. It is also possible to form the cured resin layer 17b. In this case, since the cured resin layer 17b exists also at the part to be cut and divided, handling when a thin glass substrate of about 0.5 mm or less is used becomes easy.
[0038]
According to such a manufacturing method, since it is not necessary to use an exposure mask when curing the photocurable resin, there is an advantage in production work that handling between the bonding process and the curing process becomes easy. Further, the light shielding film 31 serves as a mark when a cut flaw is provided on the glass substrate, and workability is improved.
[0039]
Next, a third embodiment will be described with reference to FIG. The organic EL display device 40 covers the first glass substrate 11, the second glass substrate 12 disposed substantially parallel to the organic EL display device 16, the organic EL element 16 formed on the first glass substrate 11, and the organic EL element 16. The first glass substrate and the second glass substrate are pasted and fixed, and the photocurable resin layer 17 that protects the organic EL element 16 from the external atmosphere is the same as the previous embodiment. The embodiment differs in that a protective layer 41 is formed between the organic EL element 16 and the photocurable resin layer 17.
[0040]
The protective layer 41 is made of GeO, SiO _x , SiN, TiO ₂ , Al ₂ O ₃ Insulating films such as metal oxides and nitrides are preferable, and insulating films with high moisture resistance are particularly preferable. The protective layer 41 is formed from the viewpoint of effectively preventing adverse effects due to the external environment between the time when the organic EL element forming step is completed and the time when the photocurable resin coating step is performed. Immediately after the process is completed, it is preferable to continuously form a film using a film forming apparatus having the same environment as the film forming apparatus in which the cathode layer 15 of the organic EL element 16 is formed. It is preferable not to apply excessive heat. For example, it is formed continuously without breaking the vacuum by vapor deposition. In addition, when the protective layer 41 has a thickness of at least 0.4 μm or more, preferably 0.9 μm or more, the protective layer 41 has a high effect of effectively suppressing the generation of dark spots generated in the organic EL display device 10. The thickness is preferably 1 to 2 μm.
[0041]
By providing such a protective layer 41, it is possible to reduce the influence of the external atmosphere during the period from the completion of the organic EL element 16 formation step to the coating step with the photocurable resin. Further, in the completed organic EL display device 40, the resistance to the external atmosphere can be further improved.
[0042]
Furthermore, when 1 to 10 wt% of a material having a drying function such as BaO is mixed in the photocurable resin layer 17, the moisture resistance is improved as compared with the case of using only the photocurable resin layer 17. For example, in the organic EL display device according to the first embodiment in which the photocurable resin layer 17 is formed using 5 wt% BaO mixed in a photocurable resin, the environment is 60 ° C. and 90% RH. In the continuous light emission test, generation and growth of dark spots were hardly observed even after 20 days.
[0043]
In the above-described embodiment, the step of coating the photocurable resin layer on the first glass substrate on which the organic EL element is formed and bonding the second glass substrate from above is performed. It is good also as the process which coats the 1st glass substrate which formed the organic EL element from the upper side by coating a photocurable resin layer on the 2nd glass substrate so that an organic EL element may become the inside. It is clear.
[0044]
Hereinafter, the present invention will be described with reference to specific examples.
Example 1
A 150 mm × 150 mm first glass substrate 11 and a second glass substrate 12 having a thickness of 0.5 mm are prepared, and an ITO transparent electrode having a predetermined pattern corresponding to a plurality of organic EL display devices is provided on the first glass substrate 11. .2 μm formed thereon, and TPD as a hole transport layer and Alq as an organic light emitting layer by a vacuum deposition method. ₃ Each was formed into a film continuously by 20 nm. Thereafter, an Al—Li alloy was deposited as a cathode layer 15 by 50 nm using a film formation mask provided with openings having a predetermined pattern, thereby forming an organic EL element 16.
Next, the organic EL element 16 was coated on the organic EL element 16 by coating with an epoxy ultraviolet curing resin having a viscosity of 7000 cP (30X-396G manufactured by Three Bond Co., Ltd.) by a spin coating method. After that, with the two opposite sides of the second glass substrate, the central part is bent downward by its own weight so that it comes into contact with the ultraviolet curable resin layer 17 in order from the central part so that bubbles do not enter the interior. Bonding was performed.
Next, about 15000 mJ / cm from the second substrate side through an exposure mask capable of irradiating light to the ultraviolet curable resin layer 17 on each organic EL element. ² The ultraviolet resin layer 17 covering the light emitting portion of each organic EL element was selectively cured by irradiating with ultraviolet rays at an exposure amount of (365 nm). The thickness of the cured ultraviolet resin layer 17 was about 0.5 μm.
Finally, a kerf is provided on the outer surface of the first glass substrate 11 and the second glass substrate 12 at a position between the organic EL elements 16 by a scribing device, and pressure is applied from a position near the opposite side of each kerf. The substrate was cut.
A thin organic EL display device 10 having a total thickness of about 1 mm was obtained from one lot manufactured in this way. A comparative sample in which the organic EL display device 10 of 40 lots or more is formed in the same process, and the organic EL display device provided with the conventional seal layer is subjected to the organic EL element preparation step described in the above-described conventional technology. As a result, the organic EL display device manufactured according to the present invention did not have defects such as cracks and chips, and the probability of occurrence of defects was less than half compared with the manufacturing method of the comparative example, and the yield was improved. Further, the generation and growth of dark spots were also tested in an environment of 60 ° C. and 90% RH. As a result, generation and growth of dark spots were effectively reduced, and excellent sealing performance was exhibited.
[0045]
Example 2
An organic EL element 16 having the same configuration as that of Example 1 was formed on the first glass substrate in the same process. However, after forming the cathode layer 15 of the organic EL element, GeO was continuously deposited by 1 μm using the same vacuum film forming apparatus as the cathode layer 15 without breaking the vacuum. The subsequent steps were the same as those in Example 1.
The organic EL display device obtained in this example also had no defects such as cracks or chips as compared with the above-described comparative sample, and the yield was improved. In addition, in the test under the environment of 60 ° C. and 90% RH, the generation and growth of dark spots were hardly changed even after 20 days, and both the life and the yield were improved.
[0046]
The above-described embodiments are preferable specific examples of the present invention, and thus various technically preferable limitations are given. However, the scope of the present invention is not limited to these aspects. For example, instead of a glass substrate, a material using a first substrate and / or a second substrate made of plastic such as PP (polypropylene) or PES (polyether sulfide) may be used, or cutting scratches may be provided only on the outside of the substrate. Instead, various modifications such as providing a cut on the inner surface of the substrate are also included in the present invention.
[0047]
【The invention's effect】
As described above, according to the present invention, by forming a plurality of organic EL elements on the first substrate, sealing them together and then cutting them to produce a plurality of organic EL display devices, Mass productivity is improved.
Moreover, since the uncured photocurable resin layer occupies most between adjacent organic EL display devices to be cut, it can be cut stably and the yield is improved.
Thus, the manufacturing cost of the organic EL display device can be reduced.
In addition, since the dimensional accuracy can be stably cut, and it is not necessary to provide a seal or the like as in the conventional example between the end of the EL element light emitting region and the end of the substrate. A narrow frame can be achieved. Thereby, the ratio for which the organic EL element light emission part accounts in an organic EL display apparatus can be taken large. In addition, since the proportion of the organic EL display devices adjacent to each other on the element substrate can be reduced, it is possible to reduce the number of chips of the substrate to be removed by cutting, thereby reducing the cost.
Furthermore, a thin organic EL display device having a structure in which an organic EL element is sealed between a pair of substrates and having a thickness of 1.5 mm or less, which is difficult to manufacture with a conventional manufacturing method, has a high yield. Can get.
[Brief description of the drawings]
FIG. 1 is a schematic front view showing a first embodiment of an organic EL display device according to the present invention.
2 is a schematic cross-sectional view showing an AA portion of the organic EL display device of FIG. 1. FIG.
FIG. 3 is a schematic view illustrating a method for manufacturing an organic EL display device according to the present invention along manufacturing steps.
FIG. 4 is a schematic view illustrating a method for manufacturing an organic EL display device according to the present invention along manufacturing steps.
FIG. 5 is a schematic view illustrating a method of manufacturing an organic EL display device according to the present invention along manufacturing steps.
FIG. 6 is a schematic view illustrating a second embodiment of a method for manufacturing an organic EL display device according to the present invention along manufacturing steps.
FIG. 7 is a schematic cross-sectional view illustrating an organic EL display device manufactured by a third method of manufacturing an organic EL display device according to the present invention.
FIG. 8 is a schematic front view illustrating a cutting step of the method for manufacturing an organic EL element.
FIG. 9 is a schematic front view illustrating a conventional organic EL display device.
FIG. 10 is a schematic front view illustrating a conventional organic EL display device.
FIG. 11 is a schematic perspective view illustrating an organic EL element.
[Explanation of symbols]
10, 40, 90 Organic EL display device
11, 12, 30, 81, 91 glass substrate
14,83 Organic EL layer
15,84 Cathode layer
16 Organic EL elements
17 Photocurable resin layer
18, 19a, 19b, 39a, 39b, 88, 98a, 99b
20 Exposure mask
21, 31 Light shielding part (light shielding film)
22, 32 Translucent part (opening)
41 Protective layer

Claims (7)

A first substrate on which an organic EL element is formed;
An organic EL display device comprising: a photocurable resin layer formed so as to cover the organic EL element; and a second substrate fixedly disposed opposite to the first substrate through the photocurable resin layer. A method of manufacturing comprising:
Forming a plurality of organic EL display device electrode layers and organic EL elements on the first substrate;
Covering one substrate surface with a liquid photocurable resin;
Covering the photocurable resin with the other substrate on the upper surface of the photocurable resin so as not to be positively deformed upwardly;
Irradiating light from the outside of the substrate, curing a portion covering the light emitting region of the organic EL element in the photocurable resin, the photocurable resin layer not cured between the portions covering the adjacent light emitting regions Curing the photocurable resin to be present;
After the above-described photocurable resin curing step, cut scratches at the planned cutting position passing between the first substrate or the second substrate covering the light emitting region of the cured organic EL element adjacent to the photocurable resin. Applying a pressing force from the outside of the substrate to a position opposite to or near the cutting flaw at a position to be cut of a substrate different from the substrate on which the cutting flaw is provided, at the position of the cutting flaw, Cutting the substrate provided with the cutting flaws,
Thus, a plurality of organic EL display devices formed on the first substrate is divided, and a method for manufacturing an organic EL display device is provided.   The step of coating with the photocurable resin described above is performed by bringing the photocurable resin into contact with an electrode formed on a surface opposite to the first substrate side of the organic EL element, The manufacturing method of the organic electroluminescent display apparatus of Claim 1.   In the organic EL element forming step described above, the light emitting unit is formed by sequentially providing an organic EL layer and another polarity electrode layer on the translucent electrode layer provided on the first substrate, and sandwiched between both electrodes. A step of forming a plurality of organic EL elements having a protective layer so as to cover the light emitting part of each organic EL element after the organic EL element forming step. The method of manufacturing an organic EL display device according to claim 1, wherein the photocurable resin is provided in contact with the protective layer.   The method for manufacturing an organic EL display device according to claim 3, wherein the protective layer is made of an oxide or a nitride.   5. The organic EL display device according to claim 3, wherein the protective layer is continuously formed in a vacuum apparatus after the formation of an electrode with another polarity of the organic EL element. Manufacturing method.    The step of coating with the photocurable resin described above is performed by coating the photocurable resin layer on the organic EL element surface electrode of the first substrate. The manufacturing method of the organic electroluminescence display in any one.    The above-described photocurable resin curing step cures the photocurable resin in the light emitting region of the organic EL element by irradiating light from the outside of the second substrate provided with the light shielding film in the region to be cut in the subsequent step. The method for manufacturing an organic EL display device according to claim 1, wherein:

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