JPWO2008023626A1 - Organic electroluminescence device and method for producing the same - Google Patents

Abstract

The present invention relates to an organic EL device that improves adhesion between bonded organic layers in the production of an organic EL device by a bonding method, has no peeling, etc., and has improved carrier movement between bonding interfaces, and has no uneven light emission. I will provide a. The organic EL device of the present invention is an organic EL device having at least one or more organic layers between a first electrode and a second electrode, the first electrode and at least one or more organic layers on a first substrate. An organic EL member A having a second electrode, and an organic EL member B having at least one or more organic layers are bonded to each other such that the organic layers face each other, and The organic layers of the organic EL member A and the organic EL member B are sealed and bonded around the substrate so as to be shielded from the outside air, and the internal pressure and the external pressure of the sealed portion including the organic layer And the pressure difference is -50 to -100 kPa.

Description

  The present invention relates to an organic electroluminescence (EL) element formed by a bonding method and a manufacturing method thereof, and more specifically, a first substrate and a second substrate each having an organic layer are bonded together under a reduced pressure environment. The present invention relates to an organic EL element having improved adhesion and a method for producing the same.

  An organic electroluminescence (EL) element is an all-solid-state element composed of an organic material film having a thickness of only about 0.1 μm between electrodes, and the element emits light at a relatively low voltage of about 2 to 20 V. Therefore, this technology is expected as a next-generation flat display and illumination.

  In addition, recently discovered organic EL devices that use phosphorescence can in principle achieve a light emission efficiency that is approximately four times that of those using previous fluorescence. Research and development of device layer configurations and electrodes are performed all over the world.

  In addition, the structure of the organic EL element is a simple one in which an organic layer is sandwiched between a transparent electrode and a counter electrode, and the number of parts is overwhelmingly smaller than that of a liquid crystal display that is a typical flat display. Although the cost should be kept low, this is not always the case at present, and a large amount of water is drained from the liquid crystal display in terms of performance and cost.

  In particular, in terms of cost, poor productivity is considered as a factor.

Most of the organic EL devices that are currently commercialized are manufactured by a so-called vapor deposition method in which a low molecular material is deposited to form a film. In this vapor deposition method, a low-molecular compound that can be easily purified can be used as an organic EL material (high-purity material is easy to obtain), and it is easy to make a laminated structure. Although it is excellent, on the other hand, since deposition is performed under a high vacuum condition of 10 ⁻⁴ Pa or less, restrictions are imposed on the film forming apparatus, and in practice it can only be applied to a substrate with a small area, and when multiple layers are laminated In this case, the film formation takes time and the throughput is low. In particular, it becomes a problem when applied to lighting applications and large-area electronic displays, and organic EL elements are one of the causes that are not practically used in such applications.

  On the other hand, when a polymer material is used, the organic compound layer in the organic EL element can be manufactured by a coating process such as spin coating, ink jet, printing, and spraying.

  Since this can be manufactured under atmospheric pressure, it is possible to reduce the cost, and at the same time, when forming an organic layer of an organic EL element, a necessary material (polymer material and / or low molecule) is used. The material is prepared in a solution and applied in a thin film, so multiple organic materials can be mixed precisely (for example, it is easy to prepare dopants for the light-emitting host material, etc.). Although it is difficult, and it is very advantageous in terms of manufacturing cost, the counter electrode formed after forming an organic layer in a general manufacturing process is still produced in a vacuum process such as vapor deposition or sputtering. Therefore, the process eventually becomes a bottleneck and cannot be an innovative production process.

  In contrast to the above-mentioned vapor deposition system, the fact that the purity of the polymer material cannot be increased and the lamination is difficult, such as the fact that it does not reach the vapor deposition system in terms of light emitting performance, is almost practically used. Absent.

The above is the difference in the manufacturing method mainly due to the material, but when focusing on the method of forming the element itself,
(1) A method of sequentially forming a thin film on an electrode substrate (sequential film formation method),
(2) A method of bonding after forming a thin film appropriately on the electrode substrate and the counter electrode substrate (bonding method),
There is.

The advantage of the bonding method is
(1) In the sequential film formation method, a resistance electrode to be finally formed can be prepared in advance.
(2) The roll-to-roll system can be continuously produced by using a film for the substrate.
(3) The organic layer can be easily stacked if the bonding surfaces are organic layers,
Etc.

  In particular, (1) and (2) will be the driving force for dramatically improving productivity, and if the technology is completed, it will be possible to significantly reduce the manufacturing cost, which was the biggest problem of organic EL. .

  On the other hand, the roll-to-roll method is disclosed in a technique other than the bonding method.

  For example, Japanese Patent Application Laid-Open No. 2005-327667 describes a method in which a hole transport material is continuously formed by an inkjet method on an electrode substrate wound in a ribbon shape on a reel. As described in the method, since the formation of the counter electrode eventually becomes a vacuum process, the merit of the roll-to-roll method is greatly diminished, and the productivity is not substantially improved.

  As described above, the bonding method is an effective technical means for innovatively improving the productivity, but at present, the organic EL device manufactured by this method has a problem in performance and is accurate. The breakthrough has not been found and is in the process of development.

  There are several reasons for this, but considering the principle, the bonding surface when bonded is not necessarily in close contact at the molecular level, and as a result, the carrier cannot move smoothly. Further, it is expected that the bonding surface is peeled off and does not function as a light emitting element, which is a major factor.

  In particular, in the roll-to-roll method, there is always a winding process, so that the joint surface is easily peeled off during winding, and the peeling is a major problem in manufacturing, and the substrate is made of a flexible substrate such as a film or a plastic substrate. When used as a material, there is a risk of a fatal defect that the element is destroyed during use.

<Conventional technology of bonding method>
From such a viewpoint, several techniques related to the bonding method for improving the bonding failure at the time of bonding are disclosed.

  For example, Japanese Patent Laid-Open No. 9-7736 discloses a technique for improving the adhesion of a bonding surface by allowing a polymer binder to exist on the bonding surface and bonding or fusing the periphery of the element. No. -79300 discloses that the same technical idea can be applied to phosphorescence emission by combining with a technique for forming a light emitting layer by a transfer method.

  Patent Document 1 discloses a technique for improving adhesion between layers by making both bonding layers made of the same material. In Patent Document 2, two bonding surfaces are prepared by a wet method. Although a technique for bonding in a film that has not been completely dried has been introduced, both of them have insufficient adhesion at the bonding surface and are not a fundamental solution.

  In addition, Patent Document 3 describes a method of improving the adhesion of the bonding surface by pressure bonding using a metal substrate having a resin layer and an elastic layer.

  Bonding the periphery contributes to reducing the adverse effects of moisture and oxygen during driving of the element and improving the light emission lifetime, but is not a technical means that can fundamentally solve the above-mentioned peeling of the joint surface.

  The peeling of the thin film interface is not just a problem with the bonding method.

  The organic EL currently commercialized is a light-emitting element that is not flexible because glass is a substrate. As described above, an organic EL element that is an all-solid-state element is a flexible substrate such as a film. It is a great feature that it can be applied to (so-called flexible display).

  At present, it is said that insufficient gas barrier properties of the flexible substrate are delaying its practical application, but as another issue, peeling between the organic layer and the counter electrode layer is also a major issue. is there.

  This problem has not been taken up as an obvious problem in the current non-flexible element, but in principle, the adhesion between the organic substance and the metal forming the counter electrode is low, which is a fundamental problem. is there.

  Further, in a sequential film forming method that is usually applied, after forming an organic layer such as a light emitting layer or a carrier transport / injection layer, a counter electrode (usually a cathode, specifically a work function such as Al, Ca, Ba, etc.) However, if the organic layer already formed is damaged at this time, the light emission characteristics and the light emission lifetime of the organic EL element are greatly deteriorated. is there. In other words, it is impossible to form the counter electrode in a strong energy state in order to increase the adhesion between the counter electrode and the organic layer interface. In practice, the counter electrode is formed by vacuum deposition or sputtering under mild conditions. There is nothing but a situation.

  As means for solving this problem, a technique of providing a buffer layer made of a semiconductor material or metal on an organic layer closest to the counter electrode is also disclosed. Although it is possible to reduce the damage at the time of forming the counter electrode by putting such a buffer layer in between, it will definitely increase the load in the manufacturing process, which is preferable from the viewpoint of productivity. It is not a thing.

  From this point of view, consider the manufacturing process of the bonding method.

  Since the bonding is performed after forming all necessary layers, the transparent electrode and the counter electrode are formed first.

  When a metal or metal oxide film is formed, it is desired to apply high energy when it is deposited or after film formation in order to obtain a film with good performance. It can also be considered a means. In other words, if the bonding surfaces for bonding are organic layers, the transparent electrode and the counter electrode can be formed in advance by a method most suitable in terms of performance and productivity. If an organic layer is appropriately laminated thereon and bonded, and even a defect on the joint surface is improved, it can be an innovative method that is good in terms of performance and manufacturing process.

As a problem of the bonding method, the problem on the joint surface was mentioned earlier. As a result of intensive studies on this problem, for example, when organic layers are bonded to each other, carrier movement at the bonding interface is not uniform over the entire surface, and there are portions where carriers can easily flow and where flow is difficult. It turns out that it is easy. In particular, it has been found that the fluorescence method of emitting light at the interface of the organic layer has a remarkable behavior, and uneven light emission is likely to occur. On the other hand, the phosphorescence method, unlike the fluorescence method, has a light-emitting region inside the light-emitting layer, so this phenomenon is relatively difficult to occur. In particular, the relative thickness ratio of the light-emitting layer to the entire organic layer is increased. When the thickness of the light-emitting layer is increased, or when the light-emitting layers are joined to each other to form two light-emitting layers, it is understood that unevenness in light emission can be suppressed to the extent that even a microscopic observation does not reveal. It was. This is a technology that effectively utilizes the phenomenon that carrier movement at the bonding interface, which is the biggest difficulty of the bonding method, is slow, and it can be said that it has never been seen before.
JP 2002-203675 A JP 9-36667 A JP 2004-296148 A

  The object of the present invention is to improve the adhesion between bonded organic layers in the production of an organic EL element by a bonding method, to eliminate peeling and the like, to improve carrier movement between bonded interfaces, and to produce an organic layer with no light emission unevenness. It is to obtain an EL element.

  The above object of the present invention is achieved by the following means.

1. In the organic electroluminescence element having at least one organic layer between the first electrode and the second electrode, the organic electroluminescence element is:
On the first substrate, the first electrode, an organic electroluminescent member A having at least one organic layer,
On the second substrate, the second electrode, an organic electroluminescence member B having at least one organic layer,
Each of them is bonded so that the organic layers face each other,
And the organic layer of the organic electroluminescence member A and the organic layer of the organic electroluminescence member B are bonded together by sealing the periphery of the substrate so as to be shielded from the outside air,
An organic electroluminescence device, wherein a pressure difference between an internal pressure of a sealed portion including the organic layer and an external pressure (atmospheric pressure) is −50 to −100 kPa.

2. In the method for producing an organic electroluminescence device having at least one or more organic layers between the first electrode and the second electrode, the organic electroluminescence member having the first electrode and at least one or more organic layers on the first substrate. A and an organic electroluminescence member B having a second electrode and at least one organic layer on the second substrate,
The organic electroluminescent member A and the organic electroluminescent member B are bonded together by adhering the organic layers so as to face each other under a pressure of 0 to 50 kPa cut off from the outside air, and bonding and sealing the periphery of the substrate. A method for producing an organic electroluminescent element.

3. In the method for producing an organic electroluminescence device having at least one or more organic layers between the first electrode and the second electrode, the organic electroluminescence member having the first electrode and at least one or more organic layers on the first substrate. A and an organic electroluminescence member B having at least one organic layer on the second substrate, and A, are adhered to each other so as to face each other,
Furthermore, a sealing member is laminated on the second substrate,
Under a pressure of 0 to 50 kPa cut off from the outside air,
The manufacturing method of the organic electroluminescent element characterized by adhere | attaching the 1st board | substrate and the circumference | surroundings of a sealing member, sealing, and bonding the organic electroluminescent member A and the organic electroluminescent member B.

  4). 4. The method for producing an organic electroluminescent element according to 2 or 3, wherein the sealing is performed with a photocurable adhesive.

5). A photocurable adhesive is installed around at least one organic layer of the first substrate or the second substrate in advance.
Under a pressure of 0 to 50 kPa cut off from the outside air, the organic layer of the organic electroluminescent member A and the organic layer of the organic electroluminescent member B are brought into close contact with each other,
3. Production of the organic electroluminescent element according to 2 above, wherein the photocurable adhesive is cured, adhered and sealed by irradiating light from at least one of the first substrate and the second substrate. Method.

6). A photocurable adhesive is installed around at least one organic layer of the first substrate or the sealing member in advance,
Under a pressure of 0 to 50 kPa cut off from the outside air, the organic layer of the organic electroluminescent member A and the organic layer of the organic electroluminescent member B are brought into close contact with each other,
4. The method for producing an organic electroluminescent element according to 3 above, wherein the photocurable adhesive is cured, adhered, and sealed by irradiating light from at least one of the first substrate and the sealing member. .

  7). 4. The method for producing an organic electroluminescent element according to 2 or 3, wherein the sealing is performed with a heat-fusible adhesive.

8). A heat-fusible adhesive is installed around at least one organic layer of the first substrate or the second substrate in advance,
Under a pressure of 0 to 50 kPa cut off from the outside air, the organic layer of the organic electroluminescent member A and the organic layer of the organic electroluminescent member B are brought into close contact with each other,
3. The manufacturing of the organic electroluminescence device according to 2 above, wherein at least the periphery of the first substrate and the second substrate is heated to thermally melt and bond and seal the heat-fusible adhesive. Method.

9. A heat-fusible adhesive is installed around at least one organic layer of the first substrate or the sealing member in advance,
Under a pressure of 0 to 50 kPa cut off from the outside air, the organic layer of the organic electroluminescent member A and the organic layer of the organic electroluminescent member B are brought into close contact with each other,
4. The method for producing an organic electroluminescent element according to 3 above, wherein at least the periphery of the first substrate and the sealing member is heated to thermally melt and bond and seal the heat-fusible adhesive. .

  10. 2. The organic electroluminescent element according to 1 above, wherein a moisture-proof layer is provided on at least one of the first substrate and the second substrate.

  11. 10. The method for producing an organic electroluminescent element according to any one of 2 to 9, wherein at least one of the first substrate and the second substrate has a moisture-proof layer.

  12 2. The organic electroluminescent element according to 1 above, wherein a moisture absorbing member is provided on at least one of the first substrate and the second substrate.

  13. 10. The method for producing an organic electroluminescent element according to any one of 2 to 9, wherein a moisture absorbing member is provided on at least one of the first substrate and the second substrate.

  According to the present invention, in the production of an organic EL element by a bonding method, the adhesion between organic layers is good, there is no peeling, the carrier movement between the bonding interfaces is improved, and an organic EL element free from uneven light emission can be obtained.

It is a figure which shows an example of organic EL element manufacture using a vacuum bonding apparatus. It is a figure which shows the example of another organic EL element manufacture using a vacuum bonding apparatus. It is a figure which shows the example of the organic EL element which has arrange | positioned the moisture absorption member inside. It is a figure which shows the manufacture example of the organic EL element by a roll bonding apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st board | substrate 2 2nd board | substrate 3 Sealing member 101 Vacuum chamber 102 Elastic member 104 Heater

  Hereinafter, the best mode for carrying out the present invention will be described in detail, but the present invention is not limited to this.

The present invention relates to the production of an organic EL element by a bonding method,
In the method for producing an organic electroluminescence device having at least one or more organic layers between the first electrode and the second electrode, the organic electroluminescence member having the first electrode and at least one or more organic layers on the first substrate. A and an organic electroluminescence member B having a second electrode and at least one organic layer on the second substrate,
The organic electroluminescent member A and the organic electroluminescent member B are bonded together by adhering each organic layer so that each organic layer faces each other under a pressure of 0 to 50 kPa cut off from the outside air. This is a method for producing an organic electroluminescence element.

  More specifically, the first substrate is, for example, a glass substrate, an anode (first electrode) made of ITO on the glass substrate, a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, and the like. Each organic layer that should constitute an organic EL element selected from the above is laminated in this layer order up to an arbitrary layer. Therefore, this is an organic electroluminescent member A, and the organic EL member A is an anode side member in this case. Become. When the organic electroluminescent member A is an anode side member, the organic electroluminescent member B is a cathode side member, the second electrode is a cathode, and at least the remaining layers are formed on the cathode in this order from the cathode side.

  For example, when the organic EL member A is an anode side member and is formed from the anode to the light emitting layer on the first substrate, as the organic EL member B, on the second electrode (cathode) on the second substrate, for example, At least the electron injection layer and the electron transport layer are formed (cathode side member).

  As for the laminated structure of the organic layers, various organic layers such as an electron blocking layer and a hole blocking layer may be included as necessary, and the number of organic layers formed on each substrate is limited. Instead, it may be configured according to the order of layers constituting the organic EL element when bonded. Therefore, which organic layer of each layer of the organic EL element is formed on each member to be used as the organic EL member A (or anode side member) and the organic EL member B (or cathode side member) is organic. The most appropriate material is selected in view of the properties of the organic EL material constituting the layer, for example, glass transition temperature, melting point, crystal structure, etc., and from the viewpoint of adhesion.

  Further, the same organic layer may be formed on each member. For example, in the above case, even if the light emitting layer is formed on both members, the light emitting layer may be integrated by bonding.

  Therefore, the organic EL element formed by the method for producing an organic EL element of the present invention has a first electrode, an organic EL member A having at least one organic layer on the first substrate, and a second substrate. The second electrode and the organic EL member B having at least one organic layer are brought into close contact with each other so that the organic layers face each other under a pressure of 0 to 50 kPa (under reduced pressure) blocked from the outside air. The organic electroluminescence member A and the organic electroluminescence member B are bonded and sealed, and are bonded to each other, and after sealing, the pressure is returned to atmospheric pressure.

  When this is returned to the atmosphere (at atmospheric pressure) by sealing (for example, 10 kPa) under reduced pressure (sealing the organic layer portion), the first and second substrates are pushed to atmospheric pressure, and the first The volume of the sealed space including the organic layer formed by the substrate, the second substrate, and the sealing portion is slightly shrunk, and depending on how the gas (for example, air) in the sealed space remains, the volume is returned to atmospheric pressure. When the internal pressure changes slightly (pushing to atmospheric pressure, the internal volume changes, so the atmospheric pressure generally rises a little (~ 50 kPa)), but the organic layer can be kept under sufficient pressure by sealing under reduced pressure They can be uniformly subjected to a differential pressure from the atmospheric pressure, whereby the organic layers can be bonded uniformly.

  Therefore, the organic EL element produced by the method of the present invention, in which the organic EL member A and the organic EL member B are bonded under reduced pressure, has an internal pressure and an external pressure (in the sealed space portion including the organic layer). The organic EL element has a pressure difference from the atmospheric pressure in the range of −50 to −100 kPa (that is, the internal pressure is low).

  According to the method of the present invention, the final pressure can be controlled by adjusting the degree of vacuum at the time of bonding, and the bonding pressure can be controlled. ) Can be uniformly applied to the surface in a non-contact manner, and a stable bonding element can be obtained. It is difficult to apply pressure uniformly by mechanical pressure bonding.

  In particular, it is advantageous in a flexible element in which it is difficult to apply pressure mechanically (physically).

  Moreover, the advantage that it can seal simultaneously with bonding can be acquired.

  Below, the manufacturing method of the organic EL element by the bonding method of this invention is demonstrated in detail using figures.

  FIG. 1 shows an example of manufacturing an organic EL element of the present invention using a vacuum bonding apparatus.

  FIG. 1A shows an organic EL member A in which a first electrode 11 and an organic layer 12 are formed on a first substrate 1 and an organic in which a second electrode 21 and an organic layer 22 are formed on a second substrate. Each EL member B is shown. The organic EL member A represents, for example, an anode substrate, and the organic EL member B represents a cathode substrate. Accordingly, the first electrode 11 is an ITO electrode, the organic layer 12 is, for example, a hole transport layer and a light emitting layer, the second electrode is, for example, a cathode made of aluminum, and the organic layer 22 is, for example, an electron transport layer. By laminating these two substrates, finally, at least one or more organic layers (in this case, from the anode side) between the first substrate (first electrode) and the second substrate (second electrode), An organic electroluminescent device having a structure of a hole transport layer, a light emitting layer, an electron transport layer, and a cathode is obtained.

  As an organic layer (bonding layer) to be bonded, any of functional layers constituting an organic EL element may be used, for example, any of a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, an electron injection layer, and the like. But you can.

  FIG. 1B shows a sealing material (adhesive) S installed around the organic layer on the first substrate for sealing (adhesion). The adhesive may be heat-fusible or thermosetting. An adhesive may be applied, or a thermosetting adhesive sheet or the like may be used around the adhesive.

  Moreover, you may use a photocurable adhesive agent. When using a photocurable adhesive, it is preferable to provide a light source in a vacuum bonding apparatus so that light (ultraviolet rays) can be irradiated from the first substrate side or the second substrate side.

  In FIG. 1B, after arranging a thermosetting adhesive sheet around the organic layer on the first substrate of the organic EL member A, the organic EL member A is adhered and laminated so that the organic layers face each other. Temporary bonding.

  Here, the thermosetting sheet is disposed around the first substrate, but may be disposed on the second substrate or may be disposed on both substrates.

  Then, the organic layers 12 and 22 face each other the first electrode 11 on which the thermosetting sheet is disposed, the first substrate 1 having the organic layer 12, and the second substrate 21 having the second electrode 21 and the organic layer 22. The laminated body laminated | stacked is mounted in the vacuum chamber 101 of the vacuum bonding apparatus shown in FIG.1 (c). The vacuum bonding apparatus according to the present invention shown in FIG. 1 (c) includes a vacuum chamber (including a base) 101 on which organic EL members A and B to be bonded are placed, and stacked organic EL members A and B. The elastic member 102 that presses and firmly adheres to the cylinder, the cylinder 103 that drives the elastic member 102, and the thermosetting adhesive sheet are arranged in substantially the same shape so as to surround the periphery of the substrate and the organic layer. The heater 104 is provided. The heater 104 also includes a cylinder 105, and has a mechanism that allows the heater to be pressure-bonded to the adhesive sheet from the back surface of the substrate by the operation of the cylinder. Further, the vacuum chamber can be evacuated by a decompression device (not shown), and is sealed so that the vacuum chamber can be shielded from the outside air.

  As the elastic member 102 for pressing and adhering the two members to release gas between the two members, a plate having a surface layer formed of a heat-resistant elastic body such as silicon rubber or silicon sponge is used. .

  The heater 104 is, for example, a heat block that can be heated by energization and is arranged in a predetermined shape so as to surround the periphery of the substrate or the organic layer. It is possible to crimp.

  When the organic EL member A and the organic EL member B are laminated and placed in the vacuum chamber 101, the elastic member 102 is then pressed against the back surface of the second substrate with a predetermined pressure by driving the cylinder 103, The organic layer 12 on the first substrate and the organic layer 22 on the second substrate are adhered and fixed (FIG. 1D).

  The next step is to close the vacuum chamber 101, shut it off from the outside air, and evacuate to a reduced pressure, that is, to a pressure of 0 to 50 kPa (FIG. 1 (e)). At this stage, the pressure in the vicinity of the organic layer and in the organic layer interface is the same as that in the vacuum chamber 101.

  FIG. 1F shows the next step in which the heater 104 is lowered by driving the cylinder 105 in a state where it is cut off from the outside air, and the substrates are given energy necessary for curing and bonding. When a thermosetting adhesive sheet is used as the sealing material S, which is heated by pressure bonding to the back surface, the temperature is in the range of 50 to 100 ° C., and the pressure is about 0.05 to 0.20 MPa. What is necessary is just to hold | maintain for about 10 seconds.

  Thereby, a 1st board | substrate and a 2nd board | substrate adhere | attach by a thermosetting sheet, and an organic EL element is sealed and bonded.

  Of course, for the bonding, a thermosetting adhesive or a photocurable adhesive described later may be used.

  After adhering and sealing the periphery of the substrate by predetermined heating, the heaters 104 and the elastic member 102 are then pulled back to their original positions by driving the cylinders 105 and 103, and the decompression of the vacuum chamber 101 is released. (FIG. 1 (g)), sealing and pasting of the organic EL element are completed.

  In the state of FIG. 1 (f), the sealed space P blocked by the two substrates and the sealing material has the same degree of vacuum as the vacuum chamber, but the vacuum pressure is released and the surrounding pressure rises. Then, the degree of decompression of the sealed space P slightly increases depending on factors such as the volume of the sealed space, but basically increases slightly. The organic layer on the first substrate and the organic layer on the second substrate are in close contact with each other uniformly and tightly.

  In the present invention, in order to seal the organic EL element under reduced pressure (for example, 10 kPa) (the organic layer portion is sealed), for example, in the state of FIG. The sealed space P has the same degree of vacuum as the vacuum chamber. However, when sealed under reduced pressure by returning it to the atmosphere, depending on how the gas (for example, air) remains in the sealed space of the organic layer. When the pressure is returned to the atmospheric pressure, the internal volume is changed by being pushed by the atmospheric pressure, so the internal pressure changes and generally the atmospheric pressure is slightly increased (for example, ~ 50 kPa), but the internal pressure of the sealed space portion containing the organic layer is The pressure difference from the external pressure (atmospheric pressure) is in the range of −50 to −100 kPa. Basically, the first and second substrates are uniformly pressed and adhered by this differential pressure from the atmospheric pressure. Get good adhesion for carrier movement between organic layers It can be.

  FIG. 1 (h) shows a cross-sectional view of the extracted organic EL element and a view of the organic EL element viewed from above. The substrates are bonded to each other by a sealing material (adhesive or adhesive sheet) disposed around the organic layer, and the organic layers are bonded to each other to seal and form the organic EL element.

  In addition, in the above production, in bonding and sealing with a thermosetting adhesive sheet in a vacuum, rather than bonding the periphery at once, a pair of opposite sides of the thermosetting sheet arranged on the substrate in advance. It is preferable that the remaining pair of sides are bonded, closed, and sealed after heat-bonding and bonding for uniform pressing.

  For this purpose, it is preferable that the heater can be driven by an individual cylinder at least for each pair of sides.

  In these bonding and sealing processes, the first substrate and the second substrate may both be glass substrates, but at least one of them is preferably a flexible substrate. In the above, the first substrate is a glass substrate. By using two substrates as flexible films, pressure can be applied between the organic layers to be bonded more uniformly without contact, and uniform adhesion, bonding, and sealing can be performed.

  Moreover, the said vacuum bonding apparatus is the 1st board | substrate, at least one of the 2nd board | substrate, for example, in the case of FIG. 1, if a 2nd board | substrate is made into a flexible board | substrate (for example, base material consisting of a plastic film) The two substrates are continuously supplied in a strip shape (for example, from the left to the right toward the plane of FIG. 1), and the organic EL member A in which an electrode and an organic layer are formed on the first substrate formed individually, and sequentially An organic EL element can be formed by pasting and sealing.

  Thus, by using at least one of the first substrate and the second substrate as a band-shaped flexible substrate, it can be continuously supplied to improve the productivity of the organic EL element.

  In the present invention, it is preferable to have a moisture-proof layer on at least one of the first substrate and the second substrate in order to maintain the sealing effect.

  The moisture-proof layer is not limited as long as it is a layer made of a material having gas barrier properties such as water vapor, oxygen, etc. For example, a ceramic vapor-deposited layer such as silicon oxide and aluminum oxide, and these ceramic layers and impact relaxation Moisture-proof layers having a structure in which polymer layers are alternately laminated, and laminate layers (6 to 50 μm thick) such as metal foils such as copper (Cu) foil and aluminum (Al) foil, etc. Is preferably provided on the opposite side (outside) of the organic layer of the first electrode or the second electrode layer.

  For this purpose, a film having these moisture-proof layers may be used as a substrate. As a film having these moisture-proof layers, typically, for example, the ceramic layer is formed on a resin film substrate (10 to 200 μm) such as a PET film. Or a metal foil or the like laminated with, for example, a polyethylene resin film.

  As a film having a vapor deposition layer, a resin film on which silicon oxide, aluminum oxide, or the like is vapor-deposited is marketed. For example, a letterpress printing GX film can be obtained. Moreover, the metal laminated film which coated the single side | surface of metal foil with the polymer film is marketed for packaging materials. For example, there is a dry laminate film (adhesive layer / aluminum film 9 μm / polyethylene terephthalate (PET) 38 μm) (a two-component reaction type urethane adhesive having an adhesive layer thickness of 1.5 μm).

  Therefore, by using these as either a substrate or a substrate, a moisture-proof layer can be incorporated, and the moisture-proof effect by sealing can be improved.

  Another production example of the organic EL element by bonding according to the present invention is shown based on FIG.

  2A shows the first substrate 11 (organic EL member A) having the first electrode 11 and the organic layer 12 and the second substrate 21 (organic EL member B) having the second electrode 21 and the organic layer 22 as described above. Each is shown. FIG. 2B shows a case where a thermosetting adhesive sheet is disposed as the sealing material S around the organic layer of the organic EL member A, and the organic EL member A and the organic EL member B are connected to each other. The sealing member 3 is laminated | stacked from the opposite side (outside) of the organic layer of the 2nd board | substrate of the organic electroluminescent member B, and the place bonded temporarily is shown.

  The sealing member 3 is a flexible plastic sheet or film having a high gas barrier property such as water vapor or oxygen. A resin film having the moisture-proof layer is preferred. For example, the vapor deposition film etc. which used PET as a base material, such as letterpress printing GX film, are mentioned.

  If the first substrate is composed of a gas-barrier base material such as glass, the sealing member 3 can be used to efficiently seal the organic EL element from the outside air and prevent deterioration gases such as water vapor and oxygen. The influence can be suppressed.

  Next, the first electrode 11, the first substrate 1 having the organic layer 12, the second electrode 21, the second substrate 2 having the organic layer 22, and the sealing member 3, each having a thermosetting adhesive sheet, are disposed. The laminated and temporarily bonded ones are placed in the vacuum chamber 101 of the same vacuum bonding apparatus as shown in FIG. 1 (c) (FIG. 2 (c)).

  The vacuum bonding apparatus includes a vacuum chamber (including a gantry) 101 on which a laminate of the organic EL member A and the organic EL member B to be bonded is placed, an elastic member 102 for pressing, and a cylinder 103 that drives the vacuum chamber. ing. The elastic member is a pressing plate whose surface is made of an elastic material such as silicon rubber or silicon sponge, and the cylinder 103 raises and lowers the elastic member 102 by the cylinder, whereby the laminate is pressed and laminated from the back surface. The gas between the bodies can be pushed and escaped, and the laminate can be fixed tightly between the gantry.

  Moreover, the heater 104 arrange | positioned so that the circumference | surroundings of an organic layer may be enclosed in the shape substantially the same as the sealing material S (thermosetting adhesive sheet) is provided. The heater 104 also includes a cylinder 105 and has a function of heating by raising and lowering the heater with the cylinder and pressing the heater against the back surface of the sealing member. In addition, the vacuum chamber 101 can be evacuated by a decompression device (not shown) after being sealed, and has a structure in which the vacuum chamber can be decompressed by blocking it from the outside air.

  When the organic EL member A and the organic EL member B laminated with the sealing member 3 are placed in the vacuum chamber 101 (FIG. 2C), the elastic member 102 is then driven by driving the cylinder 103. Lowered and pressed against the back surface of the sealing member 3 laminated on the back surface of the second substrate with a predetermined pressure, and the organic layer 12 on the first substrate and the organic layer 22 on the second substrate were brought into close contact with each other. It is fixed as it is (FIG. 2 (d)).

  Next, the vacuum chamber 101 is closed, cut off from the outside air, and evacuated to a pressure of 0 to 50 kPa (FIG. 2 (e)). At this stage, the pressure in the vicinity of the organic layer and the interface between the organic layers is the same as that in the vacuum chamber.

  Next, the cylinder 105 is driven and the heater 104 is lowered while the vacuum is maintained at 0 to 50 kPa from the outside air, and the sealing material S (heat The curable adhesive sheet) is heated and pressure-bonded to give energy necessary for the curing and bonding (FIG. 2 (f)). When using a thermosetting adhesive sheet, the temperature may be in the range of 50 to 100 ° C., the pressure may be 0.05 to 0.20 Pa, and the time may be about 1 to 10 seconds. By this step, the sealing member 3 and the first substrate are bonded by the thermosetting adhesive sheet in a state where the organic layers of the organic EL member A and the organic EL member B are in close contact with each other.

  For the bonding and adhesion by the sealing material, it is preferable from the viewpoint of improving the adhesion between the organic layers that the pair of opposite sides around the substrate is bonded in advance and the remaining pair of sides is bonded and closed under reduced pressure. It is preferable to allow the blocks to be driven separately in this way and to bond them in two stages.

  In any case, sealing is performed by bonding the sealing member 3 and the first substrate by pressure bonding and heating of the heater 104, and the organic layers of the organic EL member A and the organic EL member B are adhered and bonded at the same time. The formed organic EL element is formed.

  Next, the cylinders 103 and 105 are driven to raise the elastic member 102 and the heater 104 and return them to their original positions. Then, the decompression is released (FIG. 2G), and the organic EL element is sealed. Bonding is complete.

  FIG. 2 (h) shows a cross-sectional view of the extracted organic EL element and a view of the organic EL element viewed from above. The substrates are bonded to each other by an adhesive disposed around the organic layer, and the organic layers are bonded to each other, thereby sealing and forming the organic EL element.

  As the sealing member, for example, a flexible gas barrier resin film such as a metal vapor deposition film can be used. Even if the first substrate is a rigid substrate such as glass, a uniform pressure is applied between the organic layers. Since it is applied, the adhesion between the organic layers is better, the carrier movement between the bonded layers is less uneven, and a uniform element can be obtained. In addition, since the sealing member can be continuously supplied, the continuous productivity of the element is also excellent.

  In order to more uniformly bond the first organic layer formed on the first substrate and the second organic layer formed on the second substrate, heat treatment may be performed in a state where the first organic layer is bonded by an elastic member. preferable. As a heating method, a heating function may be imparted to the elastic member, or a heater may be imparted (hot plate) to a gantry provided in the vacuum chamber.

  The heating temperature is lower than the lowest temperature among the softening temperature or glass transition temperature of the organic material constituting the organic layer which is lower than the melting point of any organic layer used and is generally about 80 to 160 ° C., and is 0 ° C. It is preferably 80 ° C. or lower, more preferably 40 ° C. or higher and 80 ° C. or lower. In view of temperature controllability, the temperature is preferably 40 ° C or higher.

  Moreover, after forming an organic layer on a 1st board | substrate and a 2nd board | substrate, respectively, it is preferable when the surface of each organic layer is prebaked. The solvent contained in the organic layer can be skipped to some extent by the pre-baking treatment. Heat drying for a short time at a temperature lower than the heating at the time of bonding. It is particularly effective for a large area element to remove a certain amount of solvent in advance by pre-baking before bonding. The heating temperature for the pre-bake treatment is preferably lower than the melting point of any organic layer to be used and lower than the lowest temperature among the softening temperature or glass transition temperature for the same reason as the heat treatment at the time of bonding. The pre-bake treatment is performed on the surfaces of both organic layers, but may be single-sided in some cases. As the heating method, oven drying, hot plate drying, vacuum drying, or the like can be used.

  Moreover, it is preferable that the sealing material which adhere | attaches board | substrates by applying to the display part periphery of both board | substrates is moisture proof.

  As said sealing material, the adhesive agent, for example, the adhesive agent generally used with respect to glass, a plastic substrate, etc. can be used without a restriction | limiting.

  Particularly preferred adhesives include acrylic adhesives and epoxy adhesives. Among them, an epoxy adhesive having a small shrinkage upon curing is preferable.

  Epoxy adhesives consist of an epoxy resin as the main agent and a curing agent. A compound containing the epoxy group (main agent) and a curing agent containing amines or acid anhydrides are mixed together and bonded by a curing reaction. Refers to adhesive.

  The compound containing an epoxy group includes a bisphenol A type as described above, and amines are often used as a curing agent.

  These adhesives can be provided on the substrate without particular limitation such as potting, coating, spraying, printing, etc., and can be polymerized and cured by irradiation with energy rays such as ultraviolet rays and electron beams, and heat.

  Also preferred is a thermoactive epoxy resin curing agent comprising a bisphenol-based glycidyl type epoxy resin and a thermosetting adhesive component that are three-dimensionally reticulated when heated.

  The adhesive used as the sealing material may be an ultraviolet curable adhesive. When the curing temperature affects the characteristics of the element in the thermosetting adhesive, an actinic ray curable adhesive that is polymerized and cured by energy rays such as ultraviolet rays and electron beams is preferable. In this case, an acrylic adhesive or the like can be used, and specific examples include Three Bond Co., Ltd., 3003, 3027B, 3033B, 3042B, etc., and Cemedine Co., Ltd., Cemedine Y600, Y600H.

In the case of an ultraviolet curable adhesive, the vacuum bonding apparatus is provided with a light source that can irradiate ultraviolet rays from the back surface of the first substrate, the second substrate, or the sealing member. For example, the adhesive may be cured by irradiating the substrate with a light amount of about 10 to 100 mW / cm ^{2 in} a range of 1 to 30 seconds.

  In the present specification, “ultraviolet region (light)” refers to light having a wavelength in the range of 250 nm to 400 nm, and is obtained by a high-pressure mercury lamp or halogen lamp.

  These adhesives are applied onto the substrate by a process such as coating or printing, and a pre-formed thermosetting adhesive sheet or hot melt adhesive can be used as the sealing material. . For example, TBF series made by Sumitomo 3M, among them, low-temperature adhesive type thermosetting adhesive sheets such as TBF560, etc. are mentioned, and these sheets are cut into a desired shape and placed on the substrate by sealing the sealing material on the substrate It is preferable because it can be applied.

  Moreover, in the manufacture of the organic EL element by the bonding of the present invention, a moisture absorbing member is provided on the substrate and is present in the sealing region, thereby adsorbing moisture in the element space and suppressing element deterioration. Can do. For example, a method of sticking a powdery moisture absorbing member such as calcium oxide or zeolite on, for example, a substrate around the display unit is employed. The hygroscopic member may be provided on any base material. When the sealing material is arranged, the hygroscopic member may be arranged, for example, in a region around the organic layer. FIG. 3 shows an example of an organic EL element in which the hygroscopic member D is arranged around the organic layer around the sealed space (around the organic layer).

  An organic EL element has a structure in which one or more organic layers are laminated between electrodes. For example, anode / hole injection / transport layer / light emitting layer / electron injection / transport layer / cathode, etc. The thickness of each organic layer and each thin film in these organic EL elements ranges from 1 nm to several μm, and these organic layers are on the first substrate and the second substrate. And the organic EL element of the present invention is formed by pasting them.

  Next, each organic layer constituting the organic EL element formed on the substrate in the present invention will be described.

  An organic EL element has a structure in which one or more organic layers are laminated between electrodes. For example, anode / hole injection / transport layer / light emitting layer / electron injection / transport layer / cathode, etc. / Emitter layer / Cathode structure, other than this, electron blocking layer, hole blocking layer, buffer layer, etc. In addition, carriers such as electrons can be moved smoothly.

  In each of these organic layers constituting the organic EL device, the organic light emitting material contained in the light emitting layer includes aromatic heterocyclic compounds such as carbazole, carboline, diazacarbazole, triarylamine derivatives, stilbene derivatives, polyarylenes. Examples thereof include, but are not limited to, aromatic condensed polycyclic compounds, aromatic heterocondensed ring compounds, metal complex compounds, etc., and single oligo compounds or composite oligo compounds thereof.

  The layer (film forming material) preferably contains about 0.1 to 20% by mass of a dopant in the light emitting material. Examples of the dopant include known fluorescent dyes such as perylene derivatives and pyrene derivatives, and in the case of phosphorescent light emitting layers, for example, tris (2-phenylpyridine) iridium, bis (2-phenylpyridine) (acetylacetonate). A complex compound such as an orthometalated iridium complex represented by iridium, bis (2,4-difluorophenylpyridine) (picolinato) iridium, and the like is similarly contained in an amount of about 0.1 to 20% by mass.

  The phosphorescence emission method has a light emitting region inside the light emitting layer, so it is relatively difficult to cause uneven light emission, and the phenomenon of unevenness at the bonding interface, which is the biggest difficulty of the bonding method, and the phenomenon of slow carrier movement are unlikely to occur. Therefore, compatibility with the bonding method of the present invention is good.

  As the hole injection / transport layer, conductive polymers represented by phthalocyanine derivatives, heterocyclic azoles, aromatic tertiary amines, polyvinyl carbazole, polyethylenedioxythiophene / polystyrene sulfonic acid (PEDOT: PSS), etc. In addition, for example, carbazole-based light-emitting materials such as 4,4′-dicarbazolylbiphenyl and 1,3-dicarbazolylbenzene, (di) azacarbazoles, , 3,5-tripyrenylbenzene, and the like, and low molecular light emitting materials typified by pyrene-based luminescent materials, polyphenylene vinylenes, polyfluorenes, polyvinyl carbazoles, and the like.

  Examples of the electron injection / transport layer material include metal complex compounds such as 8-hydroxyquinolinate lithium and bis (8-hydroxyquinolinate) zinc, and nitrogen-containing five-membered ring derivatives listed below. That is, oxazole, thiazole, oxadiazole, thiadiazole or triazole derivatives are preferred. Specifically, 2,5-bis (1-phenyl) -1,3,4-oxazole, 2,5-bis (1-phenyl) -1,3,4-thiazole, 2,5-bis (1 -Phenyl) -1,3,4-oxadiazole, 2- (4′-tert-butylphenyl) -5- (4 ″ -biphenyl) 1,3,4-oxadiazole, 2,5-bis ( 1-naphthyl) -1,3,4-oxadiazole, 1,4-bis [2- (5-phenyloxadiazolyl)] benzene, 1,4-bis [2- (5-phenyloxadiazolyl) -4-tert-butylbenzene], 2- (4'-tert-butylphenyl) -5- (4 "-biphenyl) -1,3,4-thiadiazole, 2,5-bis (1-naphthyl) -1 , 3,4-thiadiazole, 1,4-bis [2- (5-phenyl) Asiazolyl)] benzene, 2- (4′-tert-butylphenyl) -5- (4 ″ -biphenyl) -1,3,4-triazole, 2,5-bis (1-naphthyl) -1,3,4 -Triazole, 1,4-bis [2- (5-phenyltriazolyl)] benzene and the like.

  The film thickness of the organic EL element and each organic layer is required to be about 0.05 to 0.3 μm, and preferably about 0.1 to 0.2 μm.

As the method for forming the organic layer of the present invention, coating and printing are preferred.
As the coating, spin coating, transfer coating, extrusion coating and the like can be used. In consideration of the material use efficiency, a method capable of applying a pattern such as transfer coating and extrusion coating is preferable, and transfer coating is particularly preferable.

  Moreover, screen printing, offset printing, inkjet printing, etc. can be used for printing. As the display element, a thin film, a small element size, and high-precision high-definition printing such as offset printing and inkjet printing are preferable in consideration of overlapping RGB patterns.

  Each organic material has its own solubility characteristics (solubility parameters, ionization potential, polarity), and there are limitations on the solvents that can be dissolved. In this case, since the solubility is different from each other, the concentration cannot be generally determined. However, the type of the solvent used in the present invention is suitable for the above conditions depending on the organic EL material to be formed. May be selected from known solvents, for example, halogenated hydrocarbon solvents such as dichloromethane, dichloroethane, chloroform, carbon tetrachloride, tetrachloroethane, trichloroethane, chlorobenzene, dichlorobenzene, chlorotoluene, dibutyl ether, tetrahydrofuran, Ether solvents such as dioxane and anisole, alcohol solvents such as methanol, ethanol, isopropanol, butanol, cyclohexanol, 2-methoxyethanol, ethylene glycol, glycerin, benzene, toluene, xylene, ethylben Aromatic hydrocarbon solvents such as hexane, paraffin solvents such as hexane, octane, decane and tetralin, ester solvents such as ethyl acetate, butyl acetate and amyl acetate, N, N-dimethylformamide, N, N-dimethylacetamide Amide solvents such as N-methylpyrrolidone, ketone solvents such as acetone, methyl ethyl ketone, cyclohexanone and isophorone, amine solvents such as pyridine, quinoline and aniline, nitrile solvents such as acetonitrile and valeronitrile, thiophene, carbon disulfide And sulfur-based solvents such as

  In addition, the solvent which can be used is not restricted to these, You may mix and use 2 or more types of these as a solvent.

  Among these, preferable examples of the organic EL material are different depending on each functional layer material. However, as a good solvent, for example, an aromatic solvent, a halogen solvent, an ether solvent, and the like are preferable. Aromatic solvents and ether solvents. Examples of the poor solvent include leaves, alcohol solvents, ketone solvents, paraffin solvents, and the like. Among them, alcohol solvents and paraffin solvents are used.

  As the electrode material, in the present invention, the first electrode can be formed on the first substrate and the second electrode can be formed on the second substrate in advance, and these can be formed by an optimum process such as vapor deposition.

  Of the two electrodes, those having a work function larger than 4 eV are suitable as the conductive material used for the anode for injecting holes, such as silver, gold, platinum, palladium, etc. and their alloys, oxidation Metal oxides such as tin, indium oxide and ITO, and organic conductive resins such as polythiophene and polypyrrole are used. It is preferable that it is translucent, and ITO is preferable as a transparent electrode. As a method for forming the ITO transparent electrode, mask vapor deposition or photolithography patterning can be used, but is not limited thereto.

  As the conductive material used as the cathode, those having a work function smaller than 4 eV are suitable, such as magnesium and aluminum. Typical examples of the alloy include magnesium / silver and lithium / aluminum. The formation method can be mask vapor deposition, photolithography patterning, plating, printing, or the like, but is not limited thereto.

  In the present invention, a glass substrate and a transparent resin film are used as the substrate. Transparent resin films include polyethylene, ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer, polypropylene, polystyrene, polymethyl methacrylate, polyvinyl chloride, polyvinyl alcohol, polyvinyl butyral, nylon, polyether ether ketone. , Polysulfone, polyethersulfone, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, polyvinyl fluoride, tetrafluoroethylene-ethylene copolymer, tetrafluoroethylene-hexafluoropropylene copolymer, polychlorotrifluoroethylene, Polyvinylidene fluoride, polyester, polycarbonate, polyurethane, polyimide, polyetherimide, polyimide, polypropylene, etc. It is.

  Further, the organic EL device of the present invention can be formed by patterning the light emitting layer for each of three colors of RGB among the organic layers, and incorporating a driving circuit into a full color display body.

  Hereinafter, although manufacture of the organic EL element using a vacuum bonding apparatus is demonstrated concretely, this invention is not limited by this.

<< Production of anode side member >>
A transparent support substrate was prepared by depositing ITO (indium tin oxide) with a film thickness of 100 nm as an anode on a glass substrate of 100 mm × 100 mm × 1.1 mm. This was ultrasonically cleaned with isopropyl alcohol, dried with dry nitrogen gas, and further subjected to UV ozone cleaning for 5 minutes.

  On this transparent support substrate, a solution obtained by diluting poly (3,4-ethylenedioxythiophene) -polystyrenesulfonic acid (PEDOT / PSS Bayer, Baytron P Al 4083) to 70% with pure water, 3000 rpm, 30 seconds. After forming a film by spin coating, the film was dried at 200 ° C. for 1 hour to provide a hole injection layer having a thickness of 30 nm.

Next, a solution obtained by dissolving 60 mg of PVK (polyvinylcarbazole) and 1.5 mg of Ir (ppy) ₃ in dichlorobenzene was similarly applied by spin coating on this hole injection layer, and after film formation, the film was heated at 60 ° C. Vacuum-dried for 1 hour to form a light emitting layer having a dry film thickness of 30 nm.

Preparation of cathode side member Next, 120 nm of aluminum was vapor-deposited as a cathode on a polyethersulfone (PES) film having a thickness of 80 mm × 80 mm × 0.3 mm, and then 1 nm of lithium fluoride was vapor-deposited as a cathode buffer layer. This was transferred from a vacuum chamber to a nitrogen atmosphere, and a solution obtained by dissolving BCP (20 mg) in 10 ml of toluene using a spin coater was spin-coated (film thickness of about 10 nm) at 60 ° C. under conditions of 1000 rpm and 30 sec. Vacuum drying was performed for a time to form an electron transport layer.

Next, a solution obtained by dissolving PVK (60 mg) and 1.5 mg of Ir (ppy) ₃ in 6 ml of dichlorobenzene was similarly applied by spin coating on this electron transport layer, and after film formation, vacuum was applied at 60 ° C. for 1 hour. It dried and formed the light emitting layer with a dry film thickness of 30 m.

Formed above,
Organic EL member A (anode member);
Glass substrate // ITO (anode: 100 nm) // PEDOT / PSS (hole injection layer: film thickness 30 nm) // PVK + Ir (ppy) ₃ (light emitting layer: film thickness 30 nm),
Organic EL member B (cathode member);
Polyethersulfone (PES) film // aluminum (120 nm) cathode / lithium fluoride (1 nm) cathode buffer layer // BCP (film thickness about 10 nm) electron transport layer // PVK (60 mg) and 1.5 mg Ir (ppy) ) ₃ (film thickness 30 nm) light emitting layer,
Was bonded as shown in FIG. 2 using a vacuum bonding apparatus.

  First, a thermosetting adhesive sheet is disposed around the organic layer on the glass substrate of the organic EL member A produced above, and the organic EL member B is overlapped with the organic EL member A so that the respective light emitting layers face each other. Further, a moisture-proof film as a sealing member was laminated on the back side of the cathode member and temporarily bonded. FIG. 2 (b) shows this. S shows the adhesive sheet cut and arranged so as to surround the periphery of the organic layer on the glass substrate. As the thermosetting adhesive sheet, a thermosetting adhesive sheet TBF560 (ethylene-vinyl acetate copolymer) manufactured by Sumitomo 3M Limited was used. Moreover, as the moisture-proof film as a sealing member, a GX film manufactured by Toppan Printing, which is a ceramic vapor-deposited film, was used. The sealing member was substantially the same size (100 mm × 100 mm) as the glass substrate of the organic electroluminescence member A (anode member). FIG. 2B shows this state.

  Next, the above laminate is placed on a base in the vacuum chamber 101 of the vacuum bonding apparatus with the glass substrate side of the organic electroluminescent member A (anode member) facing down, and the cylinder is driven to move the elastic member 102. The laminated body was fixed by pressing down from the back side of the sealing member 3 to bring the organic layers into close contact with each other (FIG. 2D). At the same time, the vacuum chamber was shut off from the outside air and evacuated with a vacuum pump (not shown) to raise the vacuum to a pressure of about 1 kPa (FIG. 2 (e)).

  The degree of vacuum is adjusted and maintained within the above range, and this time, the heater driving cylinder 105 is driven to lower the heater 104, and the sealing material S (thermosetting adhesive sheet) disposed around the organic layer on the glass substrate ) Was pressed and heated (temperature 80 ° C., pressure 0.15 MPa, 5 seconds). Thereby, the sealing member and the glass substrate were bonded. This is shown in FIG.

  When the heater 104 and the elastic member 102 were raised again by cylinder driving, the sealing member and the glass substrate were bonded around the organic layer, and an organic EL element bonded body having a sealing structure was obtained.

  After cooling the bonded portion, the vacuum chamber of the bonding apparatus was opened, the pressure was returned to atmospheric pressure, and the bonded organic EL element was taken out.

  By returning the pressure to atmospheric pressure, pressure is received from both substrates by the difference between the sealing space and atmospheric pressure, so the pressure inside the sealing space finally returned to a pressure of about 10 kPa. An organic EL device in which the light emitting layers were uniformly and closely adhered and bonded together by a differential pressure with respect to the atmospheric pressure (101.3 kPa) was obtained.

Comparative Example A temporary laminate of a laminate of an organic electroluminescent member A (anode member), an organic electroluminescent member B (cathode member), and a sealing member (GX film) used in the examples (FIG. 2 (b) )) Was used to produce an organic EL element with a roll laminating apparatus.

  As a roll laminating device (FIG. 4), using MC MC MRK-650Y, adjusting the gap between the rolls, a heated rubber roll at a surface pressure of 0.5 MPa, a speed of 10 mm / sec, and a temperature of 80 ° C. The thermosetting adhesive sheet (sealing material) was thermoset by passing, and the sealing member and the glass substrate were bonded and sealed, and the anode member and the cathode member were bonded together to produce an organic EL element.

When the above element was energized ( ^2.5 mA / cm ² ) and continuously emitted, the organic EL element obtained by the bonding according to the method of the present invention was a comparative example in terms of all of the light emission unevenness and light emission luminance. It was an element superior to the organic EL element bonded and produced using the roll bonding apparatus.

Claims (13)

In the organic electroluminescence element having at least one organic layer between the first electrode and the second electrode, the organic electroluminescence element is:
On the first substrate, the first electrode, an organic electroluminescent member A having at least one organic layer,
On the second substrate, the second electrode, an organic electroluminescence member B having at least one organic layer,
Each of them is bonded so that the organic layers face each other,
And the organic layer of the organic electroluminescence member A and the organic layer of the organic electroluminescence member B are bonded together by sealing the periphery of the substrate so as to be shielded from the outside air,
An organic electroluminescence device, wherein a pressure difference between an internal pressure of a sealed portion including the organic layer and an external pressure (atmospheric pressure) is −50 to −100 kPa. In the method for producing an organic electroluminescent element having at least one or more organic layers between the first electrode and the second electrode, the organic electroluminescent member having the first electrode and at least one or more organic layers on the first substrate. A and an organic electroluminescence member B having a second electrode and at least one organic layer on the second substrate,
The organic electroluminescent member A and the organic electroluminescent member B are bonded together by adhering the organic layers so as to face each other under a pressure of 0 to 50 kPa cut off from the outside air, and bonding and sealing the periphery of the substrate. A method for producing an organic electroluminescent element. In the method for producing an organic electroluminescence device having at least one or more organic layers between the first electrode and the second electrode, the organic electroluminescence member having the first electrode and at least one or more organic layers on the first substrate. A and an organic electroluminescence member B having at least one organic layer on the second substrate, and A, are adhered to each other so as to face each other,
Furthermore, a sealing member is laminated on the second substrate,
Under a pressure of 0 to 50 kPa cut off from the outside air,
The manufacturing method of the organic electroluminescent element characterized by adhere | attaching the 1st board | substrate and the circumference | surroundings of a sealing member, sealing, and bonding the organic electroluminescent member A and the organic electroluminescent member B. The method for producing an organic electroluminescent element according to claim 2 or 3, wherein the sealing is performed with a photocurable adhesive. A photocurable adhesive is installed around at least one organic layer of the first substrate or the second substrate in advance.
Under a pressure of 0 to 50 kPa cut off from the outside air, the organic layer of the organic electroluminescent member A and the organic layer of the organic electroluminescent member B are brought into close contact with each other,
3. The organic electro according to claim 2, wherein the photocurable adhesive is cured, adhered and sealed by irradiating light from at least one of the first substrate and the second substrate. Manufacturing method of luminescence element. A photocurable adhesive is installed around at least one organic layer of the first substrate or the sealing member in advance,
Under a pressure of 0 to 50 kPa cut off from the outside air, the organic layer of the organic electroluminescent member A and the organic layer of the organic electroluminescent member B are brought into close contact with each other,
4. The organic electroluminescence according to claim 3, wherein the photocurable adhesive is cured, adhered and sealed by irradiating light from at least one of the first substrate and the sealing member. Device manufacturing method. The method for manufacturing an organic electroluminescent element according to claim 2 or 3, wherein the sealing is performed with a heat-fusible adhesive. A heat-fusible adhesive is installed around at least one organic layer of the first substrate or the second substrate in advance,
Under a pressure of 0 to 50 kPa cut off from the outside air, the organic layer of the organic electroluminescent member A and the organic layer of the organic electroluminescent member B are brought into close contact with each other,
3. The organic electrolysis according to claim 2, wherein at least the periphery of the first substrate and the second substrate is heated to thermally melt and bond and seal the heat-fusible adhesive. Manufacturing method of luminescence element. A heat-fusible adhesive is installed around at least one organic layer of the first substrate or the sealing member in advance,
Under a pressure of 0 to 50 kPa cut off from the outside air, the organic layer of the organic electroluminescent member A and the organic layer of the organic electroluminescent member B are brought into close contact with each other,
The organic electroluminescence according to claim 3, wherein at least the periphery of the first substrate and the sealing member is heated to thermally melt and bond and seal the heat-fusible adhesive. Device manufacturing method. The organic electroluminescence device according to claim 1, further comprising a moisture-proof layer on at least one of the first substrate and the second substrate. The method for manufacturing an organic electroluminescent element according to any one of claims 2 to 9, wherein at least one of the first substrate and the second substrate has a moisture-proof layer. The organic electroluminescence element according to claim 1, wherein a moisture absorbing member is provided on at least one of the first substrate and the second substrate. The method for producing an organic electroluminescent element according to any one of claims 2 to 9, wherein a moisture absorbing member is provided on at least one of the first substrate and the second substrate.