JP2010140980A - Functional organic substance element, and functional organic substance apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a functional organic substance element and a functional organic substance apparatus thin and light weight, excellent in sealing performance for blocking invasion of an external substance such as oxygen, water or the like, and suitable for a color display or the like. <P>SOLUTION: In this functional organic substance element, an organic thin film transistor having an organic semiconductor layer 4 is first formed on an insulating substrate 1, and a first sealing layer 31 to block invasion of the external substance into the organic semiconductor layer 4 is then formed so as to coat the organic thin film transistor by a deposition method and an application method which seldom give damages to the organic semiconductor layer 4 when forming it. Apart from the above, a second sealing layer 33 having high sealing performance is formed in an organic polymer resin material 32 by a plasma CVD method, and the organic polymer resin material 32 provided with the second sealing layer 33 is then pasted on to the substrate 1 provided with the first sealing layer 31 by a damp proofing resin 34. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a functional organic element and a functional organic device, and more particularly to a functional organic element suitable for a color display or the like and a sealing structure of the functional organic device.

  In recent years, with the diversification of information devices, various demands have been made on display devices, such as an increase in screen size, thickness reduction, weight reduction, power consumption reduction, and cost reduction. Conventionally, a liquid crystal display has been mainly used as a thin display device. The liquid crystal element is further characterized in that it can be driven at a low voltage and has low power consumption. However, since the liquid crystal display is a light transmission type display device and requires a backlight light source, there is a limit to reduction in thickness and weight.

On the other hand, in 1987, Tang et al. Proposed a light-emitting element capable of emitting light with high brightness using an organic thin film as a light-emitting layer (CW Tang and SA VanSlyke, Appl. Phys. Lett., 51, 913 (1987); In this document, this light-emitting element is called an organic EL (Electroluminescence) element.) The organic EL device announced by Tang et al. Is composed of 1,1-bis (4-bis (4-tolyl) aminophenyl) cyclohexane (TAPC) and tris (8-quinolinolato) aluminum (III) on an ITO transparent electrode as an anode. ) Two organic semiconductor layers made of (Alq ₃ ) are stacked, and a cathode is deposited thereon. The TAPC layer functions as a hole transport layer. The Alq ₃ layer has two functions, the Alq ₃ layer near the interface with the TAPC layer functions as a green light emitting layer having electron transport properties, and the Alq ₃ layer on the cathode side functions as an electron transport layer. As described above, the organic EL element is substantially composed of an organic semiconductor layer having a three-layer structure of a hole transport layer / a light emitting layer / an electron transport layer. Since then, various element structures have been proposed, but this basic structure has not changed.

  An organic EL display using an organic EL element as a display element has a fast response speed and is a self-luminous type, so that it can form a clear image with high brightness, high contrast, and no viewing angle dependency. High display performance. In addition, since the structure is simple and a backlight light source is not required, it is advantageous in reducing the thickness, weight, and cost as compared to a liquid crystal display, and it can be driven at a low voltage. Compared to lower power consumption. As described above, the organic EL display can satisfy almost all demands for display devices at a high level.

  Now, there are a passive type and an active type in the driving method of the organic EL display. A passive display has an advantage that the structure is simple because there is no pixel transistor. However, as the number of pixels increases, the driving voltage increases and various disadvantages occur. Therefore, when the number of pixels is large, an active display which is provided with a pixel transistor in each pixel and can be driven at a low voltage and is advantageous for low power consumption and long life is suitable.

  Conventionally, a thin film transistor (TFT) configured as a field effect transistor is used as a pixel transistor of a display device including a liquid crystal display, and a polycrystalline silicon layer or an amorphous silicon is used as a channel layer thereof. Inorganic semiconductor layers such as layers have been used. However, since the formation of the inorganic semiconductor layer requires an expensive semiconductor manufacturing apparatus such as a vacuum apparatus, the formation of the inorganic semiconductor layer is a cause of an increase in the manufacturing cost of the display device or a limitation on the enlargement of the screen. become.

  On the other hand, the organic semiconductor layer can be formed by a coating method or a dipping method without using a large-scale facility such as a vacuum apparatus, so it can be easily formed at a lower cost than an inorganic semiconductor layer. It is expected to be able to cope with large screens. In addition, since the organic semiconductor layer can be formed at a relatively low temperature, it can be directly formed on a substrate having low heat resistance such as an organic polymer resin substrate (plastic substrate). It is also stable against mechanical impacts.

  Therefore, an active organic EL display provided with an organic thin film transistor (organic TFT) having an organic semiconductor layer as a channel layer as a pixel transistor has been proposed ((a) H. Sirringhaus et al., Science, 280, 1741 ( 1998), (b) A. Bodabalapur et al., Appl. Phys. Lett., 73, 142 (1998), (c) M. Kitamura et al., Appl. Phys. Lett., 83, 3410 (2003) ). In this case, all the constituent members other than the electrodes can be made of an organic material, and there is a great merit in making the organic EL display larger, thinner, lighter, and lower in cost.

  As described above, organic semiconductor elements that use organic semiconductor materials instead of inorganic semiconductor materials such as silicon currently have high display performance, can be made thinner and lighter, and have larger screens as pixel transistors. Research and development related to organic TFTs and the like that enable cost reduction are attracting attention. Furthermore, if the organic semiconductor element is formed on a flexible, organic polymer resin substrate that is thin, light, and hard to break, it can be placed on a curved surface, rolled up, and stored in various shapes. It is expected that an electronic circuit device and a display device that can be used will be realized, and the possibility of a flexible device that can take a form of use that could not be imagined in the past will open.

  However, in organic TFT elements and organic EL elements, it is known that the organic semiconductor layer and the cathode made of a metal material having a small work function are oxidized by oxygen or moisture in the air and the characteristics are remarkably deteriorated. It is necessary to protect the element with a sealing member that does not easily transmit oxygen or water.

  Therefore, in Patent Document 1 to be described later, an anode, a light emitting layer made of an organic material, and a cathode are laminated on a substrate, and at least the surface opposite to the substrate side (cathode side) of this laminate is the inner side. There has been proposed an organic EL element that is sealed by a two-layer sealing member including a first sealing layer and an outer second sealing layer.

  FIG. 10 is a cross-sectional view showing the structure of the organic EL element 100 proposed in Patent Document 1. As shown in FIG. In the organic EL element 100, a transparent anode 102, a hole injection transport layer 103, a light emitting layer 104, and a cathode 105 are laminated on a transparent glass substrate 101. The cathode 105 includes a first cathode layer 105a made of a material having a low work function and a second cathode layer 105b made of a material having a higher work function. Calcium Ca or magnesium Mg is preferably used as the material of the first cathode layer 105a, and aluminum Al, silver Ag, or gold Au is preferably used as the material of the second cathode layer 105b. Each layer of the laminate is laminated in the same plane shape, the same size, and the same position, except for the terminal portion 102a of the anode 102.

  A first sealing layer 106 is formed on the top surface (the surface opposite to the substrate side) and the side surface of the laminate, and the second sealing layer 107 is formed on the entire outside of the first sealing layer 106. Is formed. Furthermore, a sealing glass plate 108 is fixed to the upper surface of the second sealing layer 107. In Patent Document 1, these sealing members are described as follows.

  The first sealing layer 106 is a dense inorganic film made of a halide of an alkali metal element or alkaline earth metal element such as lithium fluoride LiF, and prevents the cathode 105 from being oxidized by blocking the permeation of water and oxygen. To prevent. The cathode 105 is formed of a metal material that is extremely easily oxidized by forming the first sealing layer 106 with a halide of an alkali metal element or an alkaline earth metal element instead of an oxide such as silicon oxide. Even so, the oxidation of the cathode 105 can be effectively prevented. In particular, the layer made of lithium fluoride LiF is suitable because the transmittance in the visible light region can be made higher than that of glass by forming it to an appropriate film thickness. The film forming conditions for preventing the light emitting layer and the like from being deteriorated by heat when the first sealing layer 106 to be formed is formed by vacuum vapor deposition are also described.

  The second sealing layer 107 is made of a moisture-proof resin material, for example, an acrylic resin or an epoxy resin, and prevents the first sealing layer 106 from cracking. In particular, an epoxy resin is preferable because it has high moisture resistance and high visible light transmittance. The second sealing layer 107 made of an epoxy resin can be easily formed by applying a liquid thermosetting epoxy resin or a photocurable epoxy resin and then curing it.

  In addition, by providing the first sealing layer 106, the organic solvent, oxygen, or water contained in the liquid epoxy resin is prevented from being mixed into the light emitting layer 104 when the second sealing layer 107 is formed. As a result, deterioration with time of the light emitting layer 104 is reduced.

  Further, in Patent Document 2 described later, in an organic thin film EL element laminated on a substrate, a sealing layer is provided on an element surface opposite to the substrate, and this sealing layer is further hermetically sealed with an adhesive. There has been proposed an organic EL element that is adhered and sealed to a plate or foil.

  FIG. 11 is a cross-sectional view showing an example of the structure of the organic EL element 200 proposed in Patent Document 2. As shown in FIG. In the organic EL element 200, a transparent anode 202, a hole injecting and transporting layer 203, an electron transporting and emitting layer 204, a cathode layer 205, and an inorganic sealing layer 206 are laminated on a transparent substrate 201 such as glass. The sealing layer 206 is adhered and sealed to an airtight plate such as a glass plate or a foil 208 with an adhesive 207. In Patent Document 2, these sealing members are described as follows.

The inorganic sealing layer 206 is made of an oxide such as silicon oxide SiO ₂ , a metal fluoride such as lithium fluoride LiF, a sulfide such as germanium sulfide GeS or tin sulfide SnS, and an inorganic compound having a high barrier property. Formed immediately after formation. The adhesive 207 is a low hygroscopic photo-curing adhesive, an epoxy adhesive, or the like. As the airtight plate or foil 208, a metal plate or a plastic plate can be used in addition to the glass plate.

JP 2001-338755 A (pages 3 and 4, FIG. 1) JP-A-4-338755 (page 4-6, FIG. 1))

  As described above, there is no essential difference in the sealing structure of the organic EL element proposed in Patent Document 1 and Patent Document 2, and both have substantially a three-layer structure and are composed of LiF or the like. The sealing layer is formed so as to cover the main part of the organic EL element, and an airtight sealing plate or sealing foil is attached to the sealing layer with a moisture-proof resin.

  When the main part of an organic EL element or an organic TFT element is sealed with such a three-layer sealing structure, if an inorganic glass plate is used as an airtight sealing member, the glass plate is excellent in airtightness. However, since the density of the glass is large and the thickness of the plate must be relatively thick in order to prevent the glass plate from cracking, the sealing structure is thick and heavy. In addition, it becomes impossible to form a flexible element. As described above, when a glass plate is used as the sealing member, the characteristics of the organic EL element and the organic TFT element are considerably deteriorated.

  On the other hand, if an organic polymer resin material is used as an airtight sealing member, the resin density is small and there is no risk of cracking even if the resin material thickness is reduced. It is also suitable for forming a flexible element. However, since the airtightness of the organic polymer resin material is not sufficient, the sealing performance for preventing the intrusion of oxygen and moisture in the air has to rely mainly on the sealing layer formed on the substrate side. However, since the sealing layer is formed so as to cover the organic EL element and the organic TFT element, the formation method, material, and thickness are set so as not to damage the organic semiconductor layer when the sealing layer is formed. Therefore, it is difficult to provide perfect sealing performance. For this reason, when an organic polymer resin material is used for the sealing member, the sealing performance becomes insufficient, and the deterioration of the element characteristics due to the intrusion of an external substance cannot be completely prevented, and the reliability and environmental resistance of the element Decreases.

  In addition, although the metal foil shown as a sealing member by patent document 2 is excellent in airtightness, since it does not permeate | transmit light, it cannot be used when a light transmittance is required. In addition, it is chemically stable, as thin as an organic polymer resin material, is light, can easily form a sealing structure at low cost, and is suitable for forming flexible elements. There is no metal material at present. Therefore, the advantage of using the metal foil as the sealing member is not great.

  As described above, the sealing structure does not impair the characteristics of the functional organic element and the functional organic apparatus, and the characteristics of the functional organic element and the functional organic apparatus deteriorate in the sealing member forming process. Development of a sealing structure with high sealing performance that prevents intrusion of external substances without increasing the usefulness and reliability of functional organic elements and functional organic devices is a major issue It has become.

  The present invention has been made in view of such a situation, and an object thereof is to provide a sealing member that is thin and light and that has an excellent sealing performance that prevents intrusion of external substances such as oxygen and water. Another object of the present invention is to provide a functional organic element and a functional organic apparatus suitable for a color display or the like.

That is, the present invention provides a functional organic element in which a functional organic layer is provided on a substrate.
A first sealing layer for preventing an external substance from entering the functional organic material layer is provided so as to directly or indirectly cover the functional organic material layer;
An organic polymer resin material provided with at least one main surface of a second sealing layer for preventing an external substance from entering the functional organic material layer is at least the substrate side of the first sealing layer. The functional organic layer and the first sealing layer are bonded to the opposite surface by a moisture-proof resin, and the organic polymer resin material, the second sealing layer, and the moisture-proof resin are used as the functional organic material layer and the first sealing layer. The present invention relates to a functional organic element characterized by being sealed.

  Further, the present invention relates to a functional organic device in which the functional organic element is disposed.

  The sealing structure of the functional organic element of the present invention is composed of four sealing layers. That is, first, a first sealing layer that prevents intrusion of an external substance into the functional organic material layer is provided so as to cover the functional organic material layer. And the organic polymer resin material provided with the 2nd sealing layer which prevents the penetration | invasion of the external substance to the said functional organic substance layer in at least one main surface so that this 1st sealing layer may be sealed However, at least the surface of the first sealing layer opposite to the substrate side is attached with a moisture-proof resin.

  The main difference from the sealing structure proposed in Patent Document 1 and Patent Document 2 is that the sealing member attached to the first sealing layer is the second sealing layer and the organic polymer resin. In this way, the problem of the sealing structure proposed in Patent Document 1 and Patent Document 2 is solved. That is, when a glass plate is used as the sealing member, the problem is that the sealing structure becomes thick and heavy, and it becomes impossible to form a flexible element by using the organic polymer resin material. It has been resolved. Further, when the organic polymer resin material is used as the sealing member, the sealing performance becomes insufficient, and the reliability and environmental resistance of the element are lowered. This is solved by providing a sealing layer.

  Since the second sealing layer is formed on the organic polymer resin material that is not provided with the functional organic material layer, unlike the first sealing layer, the functional organic material layer is formed at the time of formation. There is no risk of impairing the characteristics of the film, and the formation method, material, thickness, etc. are not limited. Therefore, a sealing layer having high sealing performance can be formed as the second sealing layer by selecting the best formation method, material, and thickness. On the other hand, since the first sealing layer has a high sealing performance, the second sealing layer until the organic polymer resin material having the second sealing layer is attached. In the meantime, the functional organic layer may be temporarily protected. Other than that, any material that can prevent oxygen, moisture, solvent, and the like from entering the functional organic material layer from the moisture-proof resin during or after the pasting process may be used. Therefore, the first sealing layer does not need to have a sealing performance as high as that of the second sealing layer. For this reason, the formation method, material, thickness, and the like of the first sealing layer can be selected as a first point that the functional organic material layer is not damaged during the formation.

  As described above, the sealing structure of the functional organic element of the present invention can be made thin and light by using the organic polymer resin material as a sealing member, and has a flexible shape. Therefore, the sealing structure does not impair the characteristics of the functional organic element. Moreover, the reliability of the functional organic element is reduced by the high sealing performance that prevents the deterioration of the characteristics of the functional organic element and the functional organic apparatus in the forming process of the sealing member and prevents the intrusion of an external substance. And environmental resistance can be improved.

  Moreover, since the functional organic substance apparatus of this invention is an apparatus by which the said functional organic element is arrange | positioned, the sealing structure has the characteristic similar to the sealing structure of the said functional organic substance element.

  In the functional organic element and the functional organic device of the present invention, the base is provided with a third sealing layer on at least one main surface to prevent the entry of an external substance into the functional organic layer. It is good to consist of an organic polymer resin substrate. At this time, the organic polymer resin substrate and the organic polymer resin material are preferably thin and deformable film or sheet. In this way, it is possible to realize a functional organic material device such as an electronic circuit device or an organic EL display that can be placed in various shapes such as being placed on a curved surface or rolled and stored, This opens up the possibility of flexible devices that can be used in ways that could not be imagined in the past.

The second sealing layer and / or the third sealing layer may be a single layer or a plurality of layers, and at least one layer may be a dense layer made of an inorganic compound. At this time, the dense layer made of the inorganic compound is a layer made of silicon nitride SiN, silicon oxide SiO ₂ , silicon oxynitride SiON, silicon oxide carbide SiOC, silicon nitride carbide SiCN, or aluminum oxide (alumina) Al ₂ O _3. It is good to be. Of these, the silicon nitride layer, the silicon oxide layer, and the silicon oxynitride layer are preferably formed by a chemical vapor deposition method (plasma CVD method) using plasma, and the aluminum oxide (alumina) layer is formed by a sputtering method. It is better. In particular, a silicon nitride layer formed by a plasma CVD method has high density and exhibits high sealing performance. In addition, it is preferable that a layer that is made of an organic compound such as a parylene layer, a SiNCH layer, and a SiNCOH layer and that is not easily cracked is laminated on the inorganic compound layer. This organic compound layer prevents the inorganic compound layer from cracking, and prevents cracks from penetrating the second sealing layer or the third sealing layer even when cracking occurs. To improve the sealing performance.

The first sealing layer may be a single layer or a plurality of layers, and the layer closest to the functional organic material layer may be a layer formed by a vapor deposition method, a coating method, or a printing method. . The material of the layer formed by the vapor deposition method is preferably lithium fluoride LiF, tin (IV) SnO ₂ , or aluminum oxide Al ₂ O ₃ . The material of the layer formed by the coating method is preferably a fluorine-based resin, for example, FS-1010 (trade name: Fluoro Technology) or FS-7010 (trade name: Fluoro Technology). The fluororesin layer can also be formed by a printing method such as an offset printing method or a screen printing method.

  The moisture-proof resin may be made of an ultraviolet curable resin. In this case, curing can be easily controlled by light irradiation. By using a resin that emits less gas and has a low shrinkage during curing, such as an epoxy resin or an acrylic resin, as an ultraviolet curable resin, it is possible to suppress deterioration of the characteristics of the functional organic element in the bonding step. it can. Epoxy resins are particularly preferable because they are excellent in material stability after curing. The moisture-proof resin is not limited to the ultraviolet curable resin, and a thermosetting resin can also be used.

  The functional organic material layer is a semiconductor layer and is preferably configured as a semiconductor element. The semiconductor element may be configured as an organic thin film transistor having the functional organic material layer as a channel layer. At this time, the organic thin film transistor may be configured as a sensor. For example, the optical sensor can be composed of a photodiode. In addition, the pressure sensor can be realized by combining organic TFT and pressure sensitive rubber (see http://techon.nikkeibp.co.jp/article/NEWS/20031121/60293/). .)

  Alternatively, the semiconductor element is preferably configured as an organic light emitting element having the functional organic layer as a light emitting layer. In addition, the functional organic material layer is composed of a plurality of semiconductor layers, and an organic light emitting element having a part of the light emitting layer as a light emitting layer and an organic thin film transistor having another layer as a channel layer are stacked, It is preferable that the light emission of the organic light emitting device is driven and controlled by the organic thin film transistor. An active organic EL display panel can be formed by arranging a large number of these organic light emitting elements on the surface. In the organic light emitting device having the above structure, not only the functional organic material layer and the cathode constituting the organic light emitting device, but also the functional organic material layer constituting the organic thin film transistor is protected by the sealing structure according to the present invention. Therefore, the organic thin film transistor is less damaged in the sealing member forming step, and the deterioration of the characteristics of the organic thin film transistor, for example, the mutual conductance gm, is suppressed to a small level. As a result, the organic light emitting device (organic EL device) driven with high brightness and high contrast by the organic thin film transistor can be realized. In addition, high reliability and environmental resistance can be obtained by the high sealing performance of the sealing structure according to the present invention.

  Alternatively, the semiconductor element may be configured as a light receiving element having the functional organic material layer as a photoelectric conversion layer. At this time, it is preferable to be configured as a solar cell. In this case, the functional organic material layer is preferably composed of a p-type layer made of pentacene, polythiophene, or the like and an n-type layer made of fullerene or the like (see, for example, JP-A-2007-288161).

  The functional organic material layer is a liquid crystal layer and is preferably configured as a liquid crystal element.

  In the case where the organic element is a light emitting element, a light receiving element, or a display element that does not use polarized light, and when light enters and exits between the functional organic substance layer and the outside via the organic polymer resin material, The organic polymer resin material is required not only to be made of a material having heat resistance to such an extent that no problem occurs in the sealing member forming step and the bonding step, but also to be made of a material having excellent light transmittance. Examples of such a material include polyethersulfone resin, polycarbonate resin, cycloolefin resin, polyethylene terephthalate resin, and polyethylene naphthalate resin. In addition, when the organic element is a light emitting element, a light receiving element, or a display element that does not use polarized light and light is allowed to enter and exit between the functional organic layer and the outside through the base, the base is sealed. It is necessary not only to be made of a material having heat resistance to such an extent that no problem occurs in the formation process and the bonding process of the stop member, but also to be made of a material having excellent light transmittance. Examples of such a substrate include a substrate made of the organic polymer resin described above and a glass substrate.

  On the other hand, when the organic element is an element using polarized light such as the liquid crystal element, a material having a large birefringence, such as polyethylene, is used as the material for the organic polymer resin material and / or the substrate that transmits polarized light. Naphthalate cannot be used. This is because if a material having a large birefringence is used, linearly polarized light becomes elliptically polarized light, which causes a problem that the contrast of the display image is lowered or the display image is blurred. Examples of the resin material having no birefringence include polyethersulfone resin. In addition, by adding inorganic fine particles having opposite birefringence into an organic polymer resin having birefringence, a composite material by a crystal doping method that reduces the birefringence of the organic polymer resin is obtained. It can also be used.

  When light transmittance is not necessary, the organic polymer resin material and / or the base material has heat resistance to such an extent that no problem occurs in the sealing member forming process and the bonding process. There are no other restrictions. For example, as the material of the organic polymer resin material, a polyimide resin or a liquid crystal polymer resin can be used in addition to the organic polymer resin described above. The liquid crystal polymer resin has excellent properties such as extremely low water absorption and small dimensional change due to water absorption. In addition to the organic polymer resin substrate and glass substrate described above, a polyimide resin substrate, a liquid crystal polymer resin substrate, and a metal substrate such as stainless steel whose surface is covered with an insulating film can be used as the substrate.

  In the functional organic device of the present invention, the functional organic elements are preferably arranged in an array. For example, the organic light emitting element is provided in each pixel, and the light emission is configured as a full-color image display device controlled by an organic thin film transistor provided between the base and the first sealing layer. It is good to be. In this case, as described above, not only the organic light emitting device but also the organic thin film transistor is protected by the sealing structure according to the present invention, so that the organic light emitting device can be driven with high brightness and high contrast by the organic thin film transistor. A full-color image display device (organic EL display) can be realized. In addition, this image display device can realize high reliability and environmental resistance, and can be made to take various shapes such as being placed on a curved surface or being rolled up and stored. It can also be a display.

  At this time, the organic polymer resin material, the second sealing layer, and the moisture-proof resin are provided so as to collectively seal the plurality of functional organic elements. Simple and convenient. The first sealing layer may be provided for each of the functional organic elements in consideration of wiring formation or the like, or may be provided collectively for the plurality of functional organic elements. Also good.

  Next, a preferred embodiment of the present invention will be described specifically and in detail with reference to the drawings. However, the present invention is not limited to the following examples.

Embodiment 1
In Embodiment 1, an organic TFT element provided with a sealing structure according to the present invention will be described as an example of the functional organic substance element described in claims 1 and 4 to 11.

  FIG. 1 is a cross-sectional view showing the structure of an organic TFT based on the first embodiment. This organic TFT element is configured as a top gate type field effect transistor. A source electrode 2 and a drain electrode 3 are formed on an insulating substrate 1 as the base, and are in contact with these electrodes, and at least between the electrodes. The organic semiconductor layer 4 is provided so that it may coat | cover continuously. A gate electrode 6 is formed on the organic semiconductor layer 4 via a gate insulating film 5.

  The material which comprises these members is not specifically limited. The insulating substrate 1 is a glass substrate, for example. Further, the insulating substrate 1 only needs to have an insulating surface, and the entire substrate does not need to be insulating. Therefore, the insulating substrate 1 may be a metal substrate such as stainless steel whose surface is covered with an insulating film. The metal substrate has advantages such as good heat dissipation.

  The material of the source electrode 2 and the drain electrode 3 is, for example, gold Au, platinum Pt, palladium Pd, silver Ag, and alloys thereof. Moreover, you may use the laminated film which laminated | stacked the multiple types of layer which consists of these materials as an electrode. By making the source electrode 2 and the drain electrode 3 have a laminated structure, adhesion to the underlying insulating substrate 1 and ohmic contact to the organic semiconductor layer 4 can be realized.

  The material of the organic semiconductor layer 4 is, for example, pentacene. The material of the gate insulating film 5 is, for example, parylene. Parylene is a general term for paraxylylene resins. It has a polyparaxylylene skeleton, and in addition to polyparaxylylene, several types of hydrogen atoms are substituted by chlorine or fluorine atoms. Materials such as poly (monochloroparaxylylene) have been put into practical use. Parylene is one of the few insulating films that can be directly formed on the organic semiconductor layer 4 with low damage. Further, since the gate insulating film 5 is formed by the CVD method, the gate insulating film 5 can be formed with good coverage even if unevenness exists on the substrate.

  The material of the gate electrode 6 is chromium Cr, aluminum Al, gold Au, platinum Pt, titanium Ti, palladium Pd, and alloys thereof. Further, similarly to the source electrode 2 and the drain electrode 3, a stacked film in which a plurality of layers made of these materials are stacked may be used as the gate electrode 11.

  On the gate insulating film 5 and the gate electrode 6, a sealing structure 30 that is a feature of the present embodiment is formed. The sealing structure 30 has a four-layer structure. The first sealing layer 31 that prevents external substances such as oxygen and moisture from entering the organic semiconductor layer 4, which is the functional organic material layer, is indirectly applied from above the gate insulating film 5 and the gate electrode 6. It is formed so as to cover the organic semiconductor layer 4. An organic polymer resin material 32 provided with a second sealing layer 33 that prevents intrusion of an external substance on one main surface is attached to the first sealing layer 31 with a moisture-proof resin 34. ing.

The first sealing layer 31 is composed of a single layer or a plurality of layers, and the layer closest to the organic semiconductor layer 4 may be a layer formed by a vapor deposition method, a coating method, or a printing method. This is because the damage given to the organic semiconductor layer 4 when forming the first sealing layer 31 is made as small as possible. Other than this, there is no particular limitation on the material constituting the first sealing layer 31. As a material of the layer formed by the vapor deposition method, lithium fluoride LiF, tin (IV) SnO ₂ , aluminum oxide Al ₂ O ₃ or the like is preferable. The LiF layer can be formed by resistance heating vapor deposition, and damage to the organic semiconductor layer 4 during formation is small. Moreover, since the transmittance in the visible light region can be made higher than that of glass by forming the film in an appropriate thickness, it is suitable when it is necessary that the light transmittance is excellent. The material of the layer formed by the coating method is preferably a fluorine-based resin such as FS-1010 (trade name: Fluoro Technology) or FS-7010 (trade name: Fluoro Technology). The fluorine resin layer can also be formed by a printing method such as an offset printing method or a screen printing method.

  The organic polymer resin material 32 needs to have heat resistance to such an extent that no problem occurs in the formation process or the bonding process of the second sealing layer 33. Other than this, there is no limitation on the material of the organic polymer resin material 32. For example, polyethersulfone resin, polycarbonate resin, cycloolefin resin, polyethylene terephthalate resin, polyethylene naphthalate resin, polyimide resin, or liquid crystalline polymer resin can be used. Can be used.

The second sealing layer 33 is composed of a single layer or a plurality of layers, and at least one of the layers is preferably a dense layer composed of an inorganic compound. The dense layer made of this inorganic compound is, for example, a layer made of silicon nitride SiN, silicon oxide SiO ₂ , silicon oxynitride SiON, silicon oxide carbide SiOC, silicon nitride carbide SiCN, or aluminum oxide (alumina) Al ₂ O _3. There should be. Among these, the silicon nitride layer, the silicon oxide layer, and the silicon oxynitride layer are preferably formed by a plasma CVD method, and the aluminum oxide (alumina) layer is preferably formed by a sputtering method. In particular, a silicon nitride layer formed by a plasma CVD method has high density and exhibits high sealing performance. In addition, it is preferable that a layer that is made of an organic compound such as a parylene layer, a SiNCH layer, and a SiNCOH layer and that is not easily cracked is laminated on the inorganic compound layer. This organic compound layer prevents the inorganic compound layer from cracking, and even when cracking occurs, prevents the crack from penetrating through the second sealing layer 33 and improves the sealing performance. Work.

  The moisture-proof resin 34 is preferably made of an ultraviolet curable resin. In this case, curing can be easily controlled by light irradiation. As the ultraviolet curable resin, by using a resin that generates less outgas and has a small shrinkage during curing, for example, an epoxy resin or an acrylic resin, it is possible to suppress deterioration of the characteristics of the organic TFT element in the bonding process. Epoxy resins are particularly preferable because they are excellent in material stability after curing. The moisture-proof resin 34 is not limited to an ultraviolet curable resin, and a thermosetting resin can also be used.

  The surface of the organic polymer resin material 32 forming the second sealing layer 33 may be either the main surface of the organic polymer resin material 32 or may be provided on both main surfaces. However, as shown in FIG. 1, the one provided on the main surface close to the organic semiconductor layer 4 is released from an external substance entering through the organic polymer resin material 32 or the organic polymer resin material 32. This is more effective than providing it on the main surface on the opposite side. Further, in the arrangement in which the second sealing layer 33 is provided on the inner side and the organic polymer resin material 32 is provided on the outer side, the organic polymer resin material 32 is mechanically damaged by the external force. This is preferable. For the same reason, the sealing structure including the strong organic polymer resin material 32 that can withstand an impact caused by an external force according to the present embodiment includes a sealing structure in which a thin layer of a sealing material is simply laminated, Compared to a structure sealed with a fragile glass plate, it is more stable against impacts caused by external forces.

  Although not shown in FIG. 1, the first sealing layer 31 that covers the organic semiconductor layer 4 indirectly from the side of the gate insulating film 5 is also formed on the side of the organic TFT element. Further, a sealing structure composed of an organic polymer resin material 32, a second sealing layer 33, and a moisture-proof resin 34 is provided so as to seal the organic semiconductor layer 4 and the sealing layer 31 as a whole. A more detailed description of the sealing structure will be given in Embodiment 2 together with a manufacturing method.

Embodiment 2
In the second embodiment, as an example of the functional organic element described in claims 1, 4 to 10, 14, and 17, and the functional organic substance device described in claims 19 to 21, an organic TFT is used as a pixel transistor. An example in which a sealing structure based on the present invention is provided in an organic EL display composed of provided organic EL elements will be described.

  FIG. 2A is a partial cross-sectional view showing the structure of one pixel of the organic EL display panel based on the second embodiment, and FIG. 2B is an enlarged cross-sectional view of one subpixel 40.

  As shown in FIG. 2A, this organic EL display is configured as a full-color image display device, and each pixel of the organic EL display panel emits red light, green light, and blue light. The EL elements 20R, 20G, and 20B are arranged in the three subpixels 40. The three organic EL elements 20 </ b> R to 20 </ b> B have the same configuration except that the organic semiconductor material constituting the organic semiconductor layer 23 differs depending on the emission color.

  As shown in FIG. 2B, in each sub-pixel 40, an organic TFT 10 that is a pixel transistor is disposed in the lower portion, and an organic EL element 20 is stacked in the middle portion. In this case, the functional organic material layer is composed of a plurality of semiconductor layers, and the organic EL element 20 is formed by using the organic semiconductor layer 23 which is the partial layer of the functional layers as a light emitting layer, and the organic semiconductor layer 15 which is another layer. An organic TFT 10 is formed using the channel layer as a channel layer. The light emission of the organic EL element 20 is configured to be driven and controlled by the organic TFT 10. The organic TFT 10 is composed of a switching transistor 10S and a driving transistor 10D (hereinafter, S indicates that it relates to the switching transistor, and D indicates that it relates to the driving transistor).

  The organic TFT element 10 is configured as a bottom gate type field effect transistor. A gate electrode 11 is formed on the insulating substrate 1 which is the base, and a source electrode 13 and a drain electrode 14 are formed on the gate electrode 11 with a gate insulating film 12 interposed therebetween. An organic semiconductor layer 15 is provided so as to cover it. Further, a protective film 18 is provided on the source electrode 13, the drain electrode 14, and the organic semiconductor layer 15 so as to cover them. In addition, a connection plug 17 and a wiring 16 are formed for electrically connecting the drain electrode 14S of the switching transistor 10S to the gate electrode 11D of the driving transistor 10D.

The material constituting these members is not particularly limited, and is the same as that of the organic TFT element described in the first embodiment. The material of the protective film 18 is, for example, parylene. Parylene is a general term for paraxylylene resins as described above, and is a material having a barrier property against water vapor. In addition, it is one of the few protective films that can be directly formed on the organic TFT with low damage. Since the protective film 18 is formed by the CVD method, the protective film 18 can be formed with good coverage even if unevenness exists on the substrate. it can. The protective film 18 may be a laminated film of an organic film such as a parylene film and an inorganic film such as a silicon nitride SiN film. By forming the protective film 18 in a laminated structure, in addition to the characteristics of an organic film such as parylene, a high protective effect of a dense inorganic film can be realized. Further, a silicon oxide SiO ₂ film or a silicon oxynitride SiON film may be formed instead of the silicon nitride film.

  On the protective film 18, an anode (anode) 21, a windowed insulating film 22, an organic semiconductor layer 23, and a cathode (cathode) 24 are formed as the organic EL element 20. The anode (anode) 21 is electrically connected to the drain electrode 14 </ b> D of the driving transistor 10 </ b> D by a connection plug 19 provided on the protective film 18. The organic EL element 20 is configured as a top emission type organic EL element.

  The windowed insulating film 22 is for preventing a short circuit between the organic EL elements 20, and is formed on the protective film 18 on which the anode electrode 21 is formed by a photolithography method or the like. By using a resist material that can be baked at a low temperature as the material of the insulating film 22 with window, it is possible to prevent the deterioration of the characteristics of the organic TFT 10 when the insulating film 22 with window is formed. Since the edge of the opening of the windowed insulating film 22 is formed in a sufficiently gentle taper shape by baking, even when the cathode 24 is thin, electrical connection can be maintained without disconnection.

  The material which comprises other members is not specifically limited. However, the uppermost material in contact with the organic semiconductor layer 23 of the anode 21 can form an electrically good interface with the hole injection layer of the organic EL element 20, has a high reflectance, and has a wavelength dependency. It may be a small metallic material such as silver Ag, aluminum Al, chromium Cr, nickel Ni, or aluminum neodymium alloy AlNd. Further, in order to improve the yield, it is also important that no aggregation occurs during heating and that no hillock is generated. In view of these factors comprehensively, AlNd is particularly preferable. Furthermore, by disposing gold Au or copper Cu having high malleability in the lower layer of this material, an anode electrode structure that can correspond to a flexible display can be formed.

The cathode 24 is configured using a material that has a small work function, good light transmission, and can form an electrically good interface with the electron injection layer of the organic EL element 20. For example, an oxide or fluoride of an alkali metal element or alkaline earth metal element such as lithium oxide Li ₂ O, cesium oxide Cs ₂ O, lithium fluoride LiF or calcium fluoride CaF ₂ is disposed in the lower layer, and a thin film is formed in the upper layer It is possible to apply a laminated structure in which a light-transmitting material with good conductivity, such as a magnesium silver alloy MgAg electrode or a calcium Ca electrode, is used (see Japanese Patent Application Laid-Open No. 2008-66499).

  On the cathode (cathode) 24, a sealing structure 35 which is a feature of the present embodiment is formed. The sealing structure 35 is basically the same as the sealing structure 30 described in the first embodiment, and has a four-layer structure. A first sealing layer 31 that prevents external substances such as oxygen and moisture from entering the organic semiconductor layer 15, the organic semiconductor layer 23, and the cathode electrode 24, which are functional organic layers, It is formed so as to cover the organic semiconductor layer 23 indirectly from the upper part of the cathode electrode 24. An organic polymer resin material 36 provided with a second sealing layer 33 that prevents entry of an external substance on one main surface is attached to the first sealing layer 31 with a moisture-proof resin 34. ing.

  The sealing structure 35 of the second embodiment is different from the sealing structure 30 described in the first embodiment in that an organic polymer resin material 36 is used instead of the organic polymer resin material 32. The organic polymer resin material 36 is required not only to have the heat resistance described above but also to have excellent light transmittance with respect to visible light in order to extract the emitted light of the organic EL elements 20R to 20B through this. Examples of such a resin material include polyethersulfone resin, polycarbonate resin, cycloolefin resin, polyethylene terephthalate resin, and polyethylene naphthalate. Examples of cycloolefin resins include zeonore resin (trade name; manufactured by Nippon Zeon Co., Ltd.), which is a cycloolefin polymer (COP), and appel resin (trade name; manufactured by Mitsui Chemicals, Inc.), which is a cycloolefin copolymer (COC). .

  Since there is no change in the first sealing layer 31, the second sealing layer 33, and the moisture-proof resin 34, the materials described in Embodiment 1 can be used for these.

  In the example shown in FIG. 2, the first sealing layer 31, the organic polymer resin material 32, the second sealing layer 33, and the moisture-proof resin 34 include a plurality of organic EL elements 20 </ b> R to 20 </ b> B and an organic TFT 10 </ b> S. 10D is provided so as to be collectively sealed. When the number of elements is large, this structure may be simple. However, the first sealing layer 31 may be provided for each organic EL element 20 in consideration of wiring formation or the like.

  FIG. 3 is an explanatory diagram showing an equivalent circuit for one subpixel provided in a pixel of the organic EL display panel and a driving method thereof. In the organic EL display panel, the switching transistor 10S, the driving transistor 10D, the luminance signal holding capacitor 25, and the sub-pixel 40 including the organic EL element 20 are arranged in a matrix, and the switching transistor 10S in each row is selected. There are provided vertical selection lines 43 and horizontal selection lines 44 for sending luminance signals to the switching transistors 10S in each column. The vertical selection line 43 is connected to the gate electrode of the switching transistor 10S, and the horizontal selection line 44 is connected to the source electrode of the switching transistor 10S.

  During the image display operation, each sub-pixel 40 is scanned by the vertical scanning circuit 41 and the horizontal scanning circuit 42 once in one cycle as follows. That is, a vertical selection pulse is output from the vertical scanning circuit 41 to one vertical selection line 43 for a certain period of one cycle, and the switching transistors 10S of the subpixels 40 in the row corresponding to the vertical selection line 43 are in a conductive state. become. During this fixed period, the luminance signal pulse is sequentially output from the horizontal scanning circuit 42 to each horizontal selection line 44, and the luminance signal holding capacitor 25 of each corresponding subpixel 40 is charged and discharged through the switching transistor 10S. The voltage of the luminance signal holding capacitor 25 is set to the luminance signal voltage. When the scanning of the subpixels in one row is completed, a vertical selection pulse is output to the vertical selection line 43 in the next row, and the subpixels in a new row are scanned in the same manner as described above. By repeating the above operation, all the sub-pixels are scanned once during one cycle.

  As described above, the voltage of the luminance signal holding capacitor 25 of each sub-pixel 40 is maintained at the respective luminance signal voltage for one cycle. Since the two electrodes of the luminance signal holding capacitor 25 are respectively connected to the source electrode and the gate electrode of the driving transistor 10D, the drain current of the driving transistor 10D is driven by the luminance signal voltage held in the luminance signal holding capacitor 25. Is controlled, and as a result, the luminance of the organic EL element 20 driven by the drain current is controlled.

  4 to 6 are partial cross-sectional views showing a flow of manufacturing steps of the organic EL display panel based on the second embodiment. Hereinafter, the manufacturing process of the organic EL display panel will be described with reference to the drawings.

  First, the organic TFT 10 (switching transistor 10S and drive transistor 10D) is formed by the steps shown in FIGS. 4 (a) to 4 (e).

  First, as shown in FIG. 4A, the gate electrode 11 (11S and 11D) is formed on the insulating substrate 1. At this time, the gate electrode 11 is preferably formed by patterning by photolithography and a lift-off method. That is, a photoresist layer having an opening at a position where the gate electrode 11 is to be formed is formed by patterning by photolithography, and then a gate electrode material layer is formed on the entire surface of the photoresist layer by vapor deposition or the like. Then, by removing the photoresist layer, the gate electrode material layer deposited thereon is removed, leaving only the gate electrode material layer formed in the opening as the gate electrode 11. In this step, the gate electrode 11 and the wiring 16 for electrically connecting the drain electrode 14S of the switching transistor 10S and the gate electrode 11D of the driving transistor 10D are formed in the same manner as the gate electrode 11.

  As described above, as the material of the gate electrode 11, Cr, Al, Au, Pt, Ti, Pd, and alloys thereof can be used. Alternatively, a stacked film in which a plurality of layers made of these materials are stacked may be used as the gate electrode.

  Next, as shown in FIG. 4B, a gate insulating film 12 having a via hole 51 at a predetermined position is formed. At this time, after forming a gate insulating film material layer on the substrate 1 on which the gate electrode 11 is formed, patterning is performed by photolithography and reactive ion etching (RIE) to form a via hole 51 at a predetermined position. It is good to do. At this time, by performing etching so that the Taber angle of the via hole 51 becomes a forward taper, the connection plug 17 can be smoothly embedded in the via hole 51 in the next step. As already described, parylene or the like can be used as the material of the gate insulating film 12.

  Next, as shown in FIG. 4C, the source electrode 13 (13S and 13D) and the drain electrode 14 (14S and 14D) are formed. At this time, the source electrode 13 and the drain electrode 14 are preferably patterned by the lift-off method described above. At this time, the connection plug 17 is formed so as to fill the via hole 51 at the same time, and the drain electrode 14S of the switching transistor 10S and the gate electrode 11D of the driving transistor 10D are electrically connected. As described above, Au, Pt, Pd, Ag, and alloys thereof can be used as the material for the source electrode 13 and the drain electrode 14. A stacked film in which a plurality of types of layers made of these materials are stacked may be used as the source electrode 13 and the drain electrode 14.

  Next, as shown in FIG. 4D, organic semiconductor layers 15 (15S and 15D) are formed as channel layers of the switching transistor 10S and the driving transistor 10D. At this time, for example, the organic semiconductor layer 15 of each transistor can be isolated by forming the organic semiconductor layer 15 by vapor deposition using a shadow mask. Further, a rib (bank) having a reverse taper is formed of a resist material, and during the evaporation, the rib prevents the organic semiconductor material from being deposited in a part of the region, thereby isolating between the organic semiconductor layers 15 of each transistor. Can also be performed. As described above, pentacene or the like can be used as the material of the organic semiconductor layer 15.

  Next, as shown in FIG. 4E, a protective film 18 having a via hole 52 at a predetermined position is formed on the organic TFT 10. At this time, after forming a protective film material layer on the organic TFT 10, it is preferable to form a via hole 52 at a predetermined position of the protective film material layer by photolithography and RIE. At this time, by etching so that the Taber angle of the via hole 52 becomes a forward taper, the connection plug 19 can be smoothly embedded in the via hole 52 in the next step. As described above, parylene or the like can be used as the material of the protective film 18. Further, as the protective film 18, a laminated film of a parylene film and a silicon nitride film can be used. Further, a silicon oxide film or a silicon oxynitride film may be formed instead of the silicon nitride film.

  Subsequently, the organic EL element 20 is formed by the steps shown in FIGS.

  First, as shown in FIG. 5F, the connection plug 19 and the anode 21 of the organic EL element 20 are formed on the protective film 18 by vapor deposition. At this time, the anode 21 can be patterned and formed in a predetermined region by evaporating an electrode material using a shadow mask. As described above, as the uppermost layer of the anode 21, a metal material that can form an electrically good interface with the hole injection layer of the organic EL element 20, has high reflectivity, and has low wavelength dependency. Layers such as silver Ag, aluminum Al, chromium Cr, nickel Ni, or aluminum neodymium alloy AlNd may be placed on top. Moreover, in order to improve the yield, it is also important that no aggregation occurs during heating and that no hillock is generated. In view of these factors comprehensively, the AlNd layer is particularly preferable. Furthermore, a layered structure in which a layer of a highly malleable metal material, for example, a layer of gold Au or copper Cu is arranged below the uppermost layer is preferable. Note that when it is necessary to perform patterning of the anode electrode with higher definition, it is preferable to perform patterning of the anode electrode by photolithography.

  Next, as shown in FIG. 5G, a windowed insulating film 22 is formed on the protective film 18 on which the anode 21 is formed. At this time, a positive photoresist material is used as the material of the insulating film 22 with window, this photoresist material is applied onto the protective film 18 by a spin coat method or the like, and patterned by photolithography to form a window-like shape. An opening may be formed. At this time, by baking, the windowed insulating film 22 can be cured and the organic solvent can be evaporated and removed. Baking is performed in an environment having a low oxygen concentration and a low water vapor concentration, or a resist material that can be baked at low temperature is used as the material of the insulating film 22 with window, so that the organic TFT 10 at the time of forming the insulating film 22 with window is formed. It is possible to prevent the deterioration of the characteristics.

  Next, as shown in FIG. 5 (h), an organic semiconductor layer 23 of about 4 to 5 layers constituting the organic EL element 20 is formed by vapor deposition. The organic semiconductor layer 23 includes a hole injection layer, a light emitting layer, an electron injection layer, and the like. At this time, the organic semiconductor layer 23 can be formed in a predetermined region by patterning by depositing an organic semiconductor material using a shadow mask. Moreover, in order to form the organic EL elements 20R to 20B that emit red light (R), green light (G), and blue light (B) at predetermined positions of the sub-pixels, the alignment of the shadow mask is changed, What is necessary is just to repeat the said process 3 times, changing the organic-semiconductor material to deposit. In this way, a pixel capable of full color display can be easily formed.

  Next, as shown in FIG. 5I, the cathode 24 is formed by vapor deposition. At this time, FIG. 5I shows an example in which the cathode 24 is formed on the entire surface. However, the cathode 24 may be formed by patterning only in a predetermined region by vapor-depositing an electrode material using a shadow mask. it can. There may be a region on the substrate 1 where the cathode 24 does not need to be formed, such as a wiring formation region. In such a case, by using a shadow mask, the cathode 24 can be formed only in a necessary area without forming the cathode 24 in an unnecessary area. As described above, as the material of the cathode 24, a conductive material that can form an electrically good interface with the electron injection layer of the organic EL element 20 is used.

  Finally, the sealing structure 35 that is a feature of the present embodiment is formed by the steps shown in FIGS. 6J and 6K.

  First, as shown in FIG. 6 (j), a lithium fluoride LiF layer is formed as the first sealing layer 31. At this time, an example in which the first sealing layer 31 is formed on the entire surface is shown in FIG. 6 (j). However, LiF is vapor-deposited using a shadow mask to form a LiF layer by patterning in a predetermined region. You can also As supplemented in the description of FIG. 5I, there may be a region on the substrate 1 where the cathode 24 need not be formed. In such a case, by using a shadow mask, the cathode 24 and the first sealing layer 31 are not formed in unnecessary areas, and the cathode 24 and the first sealing layer 31 are formed only in necessary areas. Can be formed. Since LiF can be formed by resistance heating vapor deposition, damage to the organic semiconductor layer 15 of the organic TFT element 10 in the forming process is reduced, and deterioration of the characteristics of the organic TFT 10 is suppressed.

In general, in an organic EL element using a silicon TFT as a pixel transistor, a silicon nitride SiN layer, a silicon oxide SiO ₂ layer, an aluminum oxide (alumina) Al ₂ O ₃ layer, or the like is used as a protective layer. The formed silicon nitride SiN layer is highly dense and exhibits high sealing performance. However, in the organic EL element using the organic TFT 10 as the pixel transistor, when the protective film is formed by the plasma CVD method, the on-current of the organic TFT 10 is significantly deteriorated due to plasma damage.

  FIG. 7 is a graph (a) showing a change in the drain current of the organic TFT 10 before and after forming the LiF layer as the first sealing layer 31 in the organic EL display panel based on the second embodiment, and a plasma as a comparative example. It is a graph (b) which shows the change of the drain current of the organic TFT 10 before and after forming the sealing layer which consists of a silicon nitride SiN layer by CVD method.

  As shown in FIG. 7A, the decrease rate of the drain current of the organic TFT 10 before and after forming the LiF layer is only (13%), which is acceptable. On the other hand, the reduction rate of the drain current of the organic TFT 10 before and after the formation of the sealing layer made of the SiN layer by the plasma CVD method is 99%, which is unacceptable.

On the other hand, as shown in FIG. 6 (k), a second sealing layer 33 is separately formed on at least one main surface of the organic polymer resin material 32. The second sealing layer 33 is composed of a single layer or a plurality of layers, at least one of which is a dense layer composed of an inorganic compound. As described in the first embodiment, this layer is formed of, for example, silicon nitride SiN, silicon oxide SiO ₂ , silicon oxynitride SiON, silicon oxide carbide SiOC, silicon nitride carbide SiCN, or aluminum oxide (alumina) Al ₂ O _3. It is the layer which consists of. Of these, the SiN layer, the SiO ₂ layer, and the SiON layer are preferably formed by a plasma CVD method, and the Al ₂ O ₃ layer is preferably formed by a sputtering method. In particular, a silicon nitride layer formed by a plasma CVD method has high density and exhibits high sealing performance. In addition, it is preferable that a layer that is made of an organic compound such as a parylene layer, a SiNCH layer, and a SiNCOH layer and that is not easily cracked is laminated on the inorganic compound layer. This organic compound layer prevents the inorganic compound layer from cracking, and even when cracking occurs, prevents the crack from penetrating through the second sealing layer 33 and improves the sealing performance. Work. In the present embodiment, it is particularly preferable to form a SiN layer on a polyethersulfone (PES) resin material by a plasma CVD method.

  Next, as shown in FIG. 6K, the substrate 1 on which the first sealing layer 31 is formed and the organic polymer resin material 32 on which the second sealing layer 33 is formed are combined with a moisture-proof resin 34. Paste together. In this step, after the first sealing layer 31 is formed, the substrate 1 on which the first sealing layer 31 is formed is exposed to the atmosphere without exposing the substrate 1 to the atmosphere. It is desirable to carry out in a vacuum vessel. However, since the organic TFT element 10 and the organic EL element 20 are covered with the first sealing layer 31, this step can be performed in the air.

  As the moisture-proof resin 34, an ultraviolet curable resin is preferably used. In this case, curing can be easily controlled by light irradiation. By using a resin that emits less gas and has a small shrinkage during curing, for example, an epoxy resin or an acrylic resin, the characteristics of the organic EL element 20 and the organic TFT element 10 in the bonding process can be reduced. Can be suppressed. Epoxy resins are particularly preferable because they are excellent in material stability after curing. In addition, the moisture-proof resin 34 is not restricted to this, A thermosetting resin can also be used.

  As said ultraviolet curable resin, what has photosensitivity to light with a wavelength of about 365 nm is used, for example. Since the PES resin material on which the SiN layer is formed transmits light with a wavelength of about 365 nm sufficiently well, bonding with an ultraviolet curable resin can be performed without any problem.

As described above, as shown in FIG. 6L, an organic EL display panel in which the sealing structure 35 that is a feature of the present embodiment is formed is obtained. FIG. 8 is a graph (a) showing the time change of the emission intensity in this organic EL display panel, and a graph showing the time change of the emission intensity L in the organic EL display panel of the reference example using a glass plate as the sealing plate. (B). In graphs (a) and (b), L ₀ is the initial emission intensity, the vertical axis indicates L / L ₀ , and the horizontal axis indicates time in arbitrary units.

  In the reference example shown in FIG. 8B, the sealing layer corresponding to the second sealing layer is not formed on the glass plate, and the LiF layer or SiN corresponding to the first sealing layer is formed on the substrate 1 side. A layer is provided. As shown in FIG. 8 (b), in the reference example, even when the LiF layer is provided or the SiN layer is provided, the decrease in the emission intensity L is relatively small and acceptable. From this result, since the sealing performance of a glass plate is high, it turns out that sufficient sealing performance is obtained by sticking a glass plate. Further, it can be seen that the LiF layer is as effective as the SiN layer as a temporary sealing layer until the glass plate is pasted and a sealing layer against intrusion of an external substance from the moisture-proof resin.

  In FIG. 8A, the substrate 1 provided with the LiF layer as the first sealing layer and the PES resin material provided with the SiN layer as the second sealing layer are bonded together. The graph in the case of this Embodiment is shown. Moreover, the graph in the case where the PES resin material in which the 2nd sealing layer is not provided as a comparative example is bonded together, and the above-mentioned case where the glass plate is bonded as a reference example is shown. In the comparative example, the decrease in the emission intensity L is remarkably large and unacceptable, indicating that the sealing performance is insufficient with the PES resin material alone. On the other hand, in the case of the present embodiment in which the PES resin material provided with the SiN layer is bonded, the light emission intensity L shows the same change as in the reference example, and the PES resin material provided with the SiN layer. Has a sealing performance equivalent to that of a glass plate.

  As described above, in the second embodiment, the organic EL element 20 is formed on the insulating substrate 1, and the sealing structure 35 according to the present invention is formed on the organic EL element 20. The active type organic EL display panel in which the light emission of the organic EL element 20 is controlled by the organic thin film transistor 10 provided between the sealing layer 31 and the sealing layer 31 is described. In the organic EL display panel having such a structure, not only the organic semiconductor layer 23 and the cathode (cathode) 24 constituting the organic EL element 20 but also the organic semiconductor layer 15 constituting the organic thin film transistor 10 is formed by the sealing structure 35. Protected.

  The sealing structure 35 has a four-layer structure, and is provided with a first sealing layer 31 formed so as to cover the organic EL element 20 and the organic thin film transistor 10 and an organic layer provided with a second sealing layer 33. A polymer resin material 32 is bonded together by a moisture-proof resin 34. By using the organic polymer resin material 32 instead of the glass plate as the sealing member, the sealing structure 35 can be made thin and light, and an element having a flexible shape can be formed.

  Since the second sealing layer 33 is formed on the organic polymer resin material 32 in which the organic EL element 20 and the organic thin film transistor 10 are not provided, there is no risk of damaging the characteristics of these elements at the time of formation. The method, material, thickness, etc. are not limited. Therefore, the second sealing layer 33 having high sealing performance can be formed by selecting the best formation method, material, and thickness. As a result, the organic polymer resin material 32 provided with the second sealing layer 33 has a high sealing performance equivalent to that of a glass plate, and the high reliability of the active organic EL display based on the present embodiment. And environmental resistance can be realized.

  On the other hand, the first sealing layer 31 is attached with the organic polymer resin material 32 provided with the second sealing layer 33 because the second sealing layer 33 has high sealing performance. It is sufficient that the organic EL element 20 and the organic thin film transistor 10 can be temporarily protected. Other than that, any material that can prevent oxygen, moisture, solvent, and the like from entering the moisture-proof resin 34 during or after the pasting process may be used. Therefore, the first sealing layer 31 does not need to have a sealing performance as high as that of the second sealing layer 33. For this reason, the formation method, material, thickness, and the like of the first sealing layer 31 can be selected as a first point that the organic thin film transistor 10 and the organic EL element 20 are not damaged during the formation. . For this reason, the organic thin film transistor 10 is less damaged in the formation process of the sealing structure 35, and an active organic EL display panel driven with high luminance and high contrast by the organic thin film transistor 10 can be realized.

  Since the organic EL element 20 is made of an organic material, damage occurs in a processing step in a high temperature region exceeding 100 ° C. The manufacturing process according to the present embodiment does not include a treatment process in a high temperature region that damages the organic EL element 20, so that the organic EL element 20 is not seriously damaged.

Embodiment 3
In Embodiment 3, as an example of the functional organic element described in claims 2 and 3 and the functional organic device described in claims 19 to 21, an organic EL provided with an organic TFT as a pixel transistor is mainly used. An example in which an organic EL display composed of elements is provided with a sealing structure based on the present invention will be described.

  FIG. 9 is a partial cross-sectional view showing the structure of one pixel of the organic EL display panel according to the third embodiment. This organic EL display panel is different from the organic EL display panel shown in FIG. 2 in that an organic polymer resin substrate 61 provided with a third sealing layer 62 is used instead of the insulating substrate 1. Is different. Since other configurations are the same as those of the organic EL display panel according to the second embodiment, only the differences will be described below, avoiding duplication.

  The method for producing the organic polymer resin substrate 61 provided with the third sealing layer 62 and the sealing effect are characterized by the method for producing the organic polymer resin material 32 provided with the second sealing layer 33. This is the same as the feature of the sealing effect. However, unlike the organic polymer resin material 32, the organic polymer resin substrate 61 does not need to transmit light. Therefore, the constituent material is not limited except that it has heat resistance that does not cause a problem in the formation process of the third sealing layer 62, and for example, the same light transmission as that of the organic polymer resin material 32. Material, polyethersulfone resin, polycarbonate resin, polycycloolefin resin (for example, sold by Optes; trade name ZEONOR film, Mitsui Chemicals; trade name OPTICA), polyethylene terephthalate resin, or polyethylene naphthalate In addition, a polyimide resin, a liquid crystalline polymer resin, etc. can be mentioned. Unlike FIG. 9, when the light emitted from the organic EL element 20 is taken out through the organic polymer resin substrate 61, the above light-transmitting material is used as the material of the organic polymer resin substrate 61. I need it.

The third sealing layer 62 is composed of a single layer or a plurality of layers, of which at least one layer is preferably a dense layer composed of an inorganic compound. The dense layer made of this inorganic compound is a layer made of silicon nitride SiN, silicon oxide SiO ₂ , silicon oxynitride SiON, silicon oxide carbide SiOC, silicon nitride carbide SiCN, or aluminum oxide (alumina) Al ₂ O ₃ . Is good. Of these, the silicon nitride layer, the silicon oxide layer, and the silicon oxynitride layer are preferably formed by a chemical vapor deposition method (plasma CVD method) using plasma, and the aluminum oxide (alumina) layer is formed by a sputtering method. It is better. In particular, a silicon nitride layer formed by a plasma CVD method has high density and exhibits high sealing performance. In addition, it is preferable that a layer that is made of an organic compound such as a parylene layer, a SiNCH layer, and a SiNCOH layer and that is not easily cracked is laminated on the inorganic compound layer. This organic compound layer prevents the inorganic compound layer from cracking, and even when cracking occurs, prevents the crack from penetrating the third sealing layer 62 and improves the sealing performance. Work.

  In the organic EL display panel according to the third embodiment, both the organic polymer resin substrate 61 and the organic polymer resin material 32 can be formed into a thin and deformable film shape or sheet shape, thereby forming a curved screen. A flexible organic EL display that can take various shapes, such as having or rolling and storing, can be configured. Conventionally, when a film-like or sheet-like organic polymer resin substrate is used as a substrate, sealing has been insufficient, and there has been a problem in reliability and environmental resistance. In the molecular resin substrate 61, since the third sealing layer 62 is provided, a flexible organic EL display having high sealing performance and high reliability and environmental resistance can be realized.

  The surface of the organic polymer resin substrate 61 that forms the third sealing layer 62 may be either the main surface or may be provided on both main surfaces. However, as shown in FIG. 9, an external material that enters through the organic polymer resin substrate 61 or a material that is released from the organic polymer resin substrate 61 is provided on the main surface closer to the organic TFT 10. This is more effective than providing the main surface on the opposite side. Further, in the arrangement in which the third sealing layer 62 is provided on the inner side and the organic polymer resin substrate 61 is provided on the outer side, the mechanical damage of the third sealing layer 62 due to external force is caused by the organic polymer resin substrate 61. This is preferable.

  As mentioned above, although this invention was demonstrated based on embodiment, it cannot be overemphasized that this invention is not limited to these examples at all, and can be suitably changed in the range which does not deviate from the main point of invention. For example, the active type example has been described as the driving method of the organic EL display, but the driving method may be a passive type.

  Moreover, although the organic TFT has shown the example which is a top gate type or a bottom gate type, and is a bottom contact structure, a top contact type may be sufficient as a top gate type or a bottom gate type. The top contact structure and the bottom contact structure are TFT structures in which the source / drain electrodes are in contact with the upper and lower surfaces of the semiconductor layer, respectively.

  Moreover, although the example in which the organic TFT is a p-channel transistor has been shown, the organic TFT may be an n-channel transistor. In this case, a stable light emission characteristic of the organic EL display panel can be obtained by electrically connecting the drain electrode of the driving transistor and the cathode of the organic EL element.

  The organic light-emitting device of the present invention is suitably used for a self-luminous color display or the like, and can contribute to the reduction in size, thickness and cost. In addition, new applications can be provided in fields where organic electroluminescent elements are used as lighting devices and the like.

It is sectional drawing which shows the structure of the organic TFT element based on Embodiment 1 of this invention. It is a fragmentary sectional view which shows the structure of the organic electroluminescent display panel based on Embodiment 2 of this invention. It is explanatory drawing which shows the equivalent circuit for 1 sub pixel provided in the pixel of the organic EL display panel, and its drive method. It is sectional drawing which shows the flow of the manufacturing process of an organic EL display panel equally. It is sectional drawing which shows the flow of the manufacturing process of an organic EL display panel equally. It is sectional drawing which shows the flow of the manufacturing process of an organic EL display panel equally. Similarly, in the organic EL display panel, a graph (a) showing a change in drain current of the organic TFT before and after forming the LiF layer as the first sealing layer, and a SiN layer by plasma CVD as a comparative example. It is a graph (b) which shows the change of the drain current of the organic TFT before and after forming a sealing layer. The graph (a) showing the time change of the light emission intensity in the organic EL display panel and the graph (b) showing the time change of the light emission intensity L in the organic EL display panel of the reference example using a glass plate as the sealing plate (b) ). It is a fragmentary sectional view which shows the structure of the organic electroluminescence display panel based on Embodiment 3 of this invention. It is sectional drawing which shows the structure of the organic EL element proposed by patent document 1. FIG. It is sectional drawing which shows an example of the structure of the organic EL element proposed by patent document 2. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Substrate, 2 ... Source electrode, 3 ... Drain electrode, 4 ... Organic-semiconductor layer, 5 ... Gate insulating film,
6 ... Gate electrode, 10 ... Organic TFT, 10S ... Switching transistor,
10D: driving transistor, 11, 11S, 11D: gate electrode,
12 ... Gate insulating film, 13, 13S, 13D ... Source electrode,
14, 14S, 14D ... drain electrode, 15 ... organic semiconductor layer, 16 ... wiring,
17 ... Connection plug, 18 ... Protective film, 19 ... Connection plug,
20, 20R, 20G, 20B ... organic EL element, 21 ... anode,
22 ... Insulating film with window, 23 ... Organic semiconductor layer, 24 ... Cathode,
25 ... Luminance signal holding capacitor, 30 ... Sealing structure,
31 ... 1st sealing layer (LiF layer etc.), 32 ... Organic polymer resin material,
33 ... 2nd sealing layer (SiN layer etc.), 34 ... moisture proof resin, 35 ... sealing structure,
36 ... Organic polymer resin material (PES plate, etc.), 40 ... Subpixel, 41 ... Vertical scanning circuit,
42: horizontal scanning circuit, 43: vertical selection line, 44: horizontal selection line, 45: power supply line,
51, 52 ... via hole, 53 ... window opening, 61 ... organic polymer resin substrate,
62 ... 3rd sealing layer (SiN layer etc.), 100 ... Organic EL element,
101 ... Transparent substrate (glass plate, etc.), 102 ... Transparent anode, 102a ... Terminal portion of anode,
103 ... hole injection transport layer, 104 ... light emitting layer, 105 ... cathode,
105a: a first cathode layer made of a material having a small work function (Ca, etc.),
105b ... a second cathode layer made of a material (such as Al) having a work function larger than that of the first cathode layer material;
106... First sealing layer (halide of alkali metal element or alkaline earth metal element such as LiF), 107... Second sealing layer (moisture-proof resin such as acrylic resin or epoxy resin),
108 ... Glass plate for sealing, 200 ... Organic EL element,
201 ... Transparent substrate (glass plate etc.), 202 ... Transparent anode, 203 ... Hole injection transport layer,
204 ... Electron transport light emitting layer, 205 ... Cathode,
206 ... inorganic sealing layer (inorganic compounds having high barrier properties such as SiO ₂ , LiF, GeS),
207 ... Adhesive (low hygroscopic photo-curing adhesive, epoxy adhesive, etc.)
208 ... Airtight plate or foil (glass plate, metal plate, plastic plate)

Claims (22)

In a functional organic element in which a functional organic layer is provided on a substrate,
A first sealing layer for preventing an external substance from entering the functional organic material layer is provided so as to directly or indirectly cover the functional organic material layer;
An organic polymer resin material provided with at least one main surface of a second sealing layer for preventing an external substance from entering the functional organic material layer is at least the substrate side of the first sealing layer. The functional organic layer and the first sealing layer are bonded to the opposite surface by a moisture-proof resin, and the organic polymer resin material, the second sealing layer, and the moisture-proof resin are used as the functional organic material layer and the first sealing layer. A functional organic element characterized by being sealed.   The said base | substrate consists of the organic polymer resin board | substrate in which the 3rd sealing layer which prevents the penetration | invasion of the external substance to the said functional organic substance layer is provided in the at least one main surface. Functional organic element.   3. The functional organic element according to claim 1, wherein the substrate and the organic polymer resin plate are thin and deformable film or sheet.   The said 2nd sealing layer and / or the said 3rd sealing layer consist of a single layer or multiple layers, The at least 1 layer is a precise | minute layer which consists of an inorganic compound. Functional organic element. The inorganic compound consisting of a dense layer, a silicon nitride SiN, silicon oxide SiO _2, silicon oxynitride SiON, silicon oxycarbide SiOC, a nitride silicon carbide SiCN, or aluminum oxide (alumina) Al ₂ O _3, claim 4 The functional organic element described in 1.   The first sealing layer is composed of a single layer or a plurality of layers, and the layer closest to the functional organic material layer is a layer formed by a vapor deposition method, a coating method, or a printing method. 2. The functional organic element described in 2.   The functional organic substance element according to claim 6, wherein the layer closest to the functional organic substance layer is made of lithium fluoride LiF.   The functional organic element according to claim 1, wherein the moisture-proof resin is made of an ultraviolet curable resin.   The functional organic material element according to claim 8, wherein the moisture-proof resin is made of an epoxy resin or an acrylic resin.   The functional organic material element according to claim 1, wherein the functional organic material layer is a semiconductor layer and is configured as a semiconductor element.   The functional organic substance element according to claim 10, which is configured as an organic thin film transistor having the functional organic substance layer as a channel layer.   The functional organic element according to claim 11, wherein the organic thin film transistor is configured as a sensor.   The functional organic substance device according to claim 10, which is configured as an organic light emitting element having the functional organic substance layer as a light emitting layer.   The functional organic material layer is composed of a plurality of semiconductor layers, and an organic light-emitting element having a part of which is a light-emitting layer and an organic thin film transistor having another layer as a channel layer are stacked to form the organic light-emitting element. The functional organic element according to claim 10, wherein light emission of the element is configured to be driven and controlled by the organic thin film transistor.   The functional organic substance element according to claim 10, wherein the functional organic substance element is configured as a light receiving element having the functional organic substance layer as a photoelectric conversion layer.   The functional organic element according to claim 15, which is configured as a solar cell.   The organic polymer resin plate and / or the organic polymer resin substrate is made of a polyethersulfone resin, a polycarbonate resin, a cycloolefin resin, a polyethylene terephthalate resin, or a polyethylene naphthalate resin. The functional organic element described in item 1.   The functional organic material element according to claim 1, wherein the functional organic material layer is a liquid crystal layer and is configured as a liquid crystal element.   The functional organic substance apparatus with which the functional organic element as described in any one of Claims 1-18 is arrange | positioned.   The functional organic device according to claim 19, wherein a plurality of the functional organic elements are arranged in an array.   21. The organic polymer resin material, the second sealing layer, and the moisture-proof resin are provided so as to collectively seal the plurality of functional organic elements. The described functional organic device.   The functional organic material device according to claim 20, which is configured as a full-color image display device.