JP2006164543A - Sealing film of organic el element, organic el display panel, and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sealing film, an organic EL display panel and a manufacturing method of the same, capable of effectively preventing the generation of cracks and thereby protecting an organic EL element from moisture and oxygen to improve reliability while maintaining durability against an impact or the like. <P>SOLUTION: The organic EL element 4 mounted on a substrate 3 is coated and sealed and structured of a plurality of layers containing a second barrier layer 51 made of silicon nitride, and a stress alleviating layer 52 arranged inside the second barrier layer 51 and made of a silicon nitride oxide with a barrier layer 53 laminated on it. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an organic EL element sealing film for covering and sealing the organic EL element in order to protect the organic EL element from moisture and oxygen, an organic EL display panel in which the organic EL element is sealed using the sealing film, and the organic EL display panel It relates to a manufacturing method.

  In recent years, an organic EL display panel using an organic electroluminescence element (organic EL element) using an organic compound such as an aluminum quinolinol complex as a light-emitting material has attracted attention. The organic EL element used in this panel has a high response speed, a wide viewing angle, and is self-luminous, so that it does not require a backlight and can contribute to thinning and weight reduction of this panel. There are various advantages. On the other hand, the organic EL element has a problem that a so-called dark spot (light emitting defect point) is generated in the display panel due to a change in the structure of the constituent material due to moisture or oxygen. Therefore, in this type of field, in order to extend the life by protecting the organic EL element from moisture and oxygen, research on techniques for sealing the element has been actively conducted.

  Conventionally, as this type of sealing structure, an organic EL element is sealed by a single layer film of silicon oxide film (SiOx), oxynitride film (SiOxNy) or nitride film (SiNx). Yes. Among these sealing films, a silicon nitride film (SiNx film) is attracting attention as a sealing film for organic EL elements because it has a very low moisture and oxygen transmittance and a high optical transmittance. Yes.

  Here, these sealing films are preferably as thin as possible from the viewpoint of optical transmittance, refractive index, and the like. However, if the film thickness becomes too thin, there is a concern that the strength against external impact may be reduced. Therefore, it is required to have a film thickness that does not reduce strength and reliability. However, since the silicon nitride film has a larger residual stress after the film formation than the silicon oxide film or the silicon oxynitride film, if the film thickness is increased to ensure the strength and the like, a short period of time is obtained based on the residual stress. There is a risk that moisture and oxygen penetrate into the sealing film through the crack and reduce the reliability of the organic EL element for sealing.

In this regard, for example, in Patent Document 1, attention is paid to the fact that the residual stress becomes tensile or compressive stress depending on the density, and the SiNx layer where the tensile stress remains and the SiNx layer where the compressive stress acts are alternately laminated By doing so, a technique is disclosed in which the residual stress of the entire sealing film is greatly reduced and cracks are effectively suppressed.
JP 2004-63304 A (see FIG. 2)

  However, although the sealing film described in Patent Document 1 is considered to reduce the residual stress of the entire film by offsetting the residual stress between layers, since the opposite stress acts exactly on each layer, There is a risk that delamination, i.e., layers in which opposite stresses occur, will delaminate with time. When such delamination occurs, the peeled portion proceeds to surface as a crack in the sealing film, and as a result, even in the sealing film described in Patent Document 1, the reliability for sealing is sufficiently improved. It wasn't something that could be done.

  On the other hand, silicon oxide films and silicon oxynitride films have less residual stress caused by film formation than silicon nitride films and are flexible, but have poor moisture and oxygen permeability. May intrude into the film, and its reliability is inferior.

  The present invention has been made under such circumstances, and can effectively prevent the occurrence of cracks while maintaining durability against impacts and the like. An object of the present invention is to provide a sealing film, an organic EL display panel, and a manufacturing method thereof that can improve reliability by protecting from oxygen.

  In order to achieve the above object, a sealing film for an organic EL element according to the present invention includes a barrier layer made of silicon nitride and a barrier layer made of silicon nitride in a sealing film that covers and seals an organic EL element mounted on a substrate. It is composed of a plurality of layers including a silicon nitride oxide and a stress relaxation layer made of at least one of silicon oxide and disposed inside the layer and on which the barrier layer is laminated.

  According to the present invention, since the sealing film for covering and sealing the organic EL element includes the barrier layer made of silicon nitride (SiNx) having a very low moisture and oxygen permeability, the organic EL element is surely sealed. Thus, the element can be effectively protected from moisture and oxygen and its reliability can be improved.

  Here, in the case of forming a barrier layer made of silicon nitride, there is a problem of coexistence of improvement in physical strength against impact and the like and prevention of generation of cracks accompanying an increase in film thickness. In this regard, in the present invention, a stress relaxation layer made of at least one of silicon oxynitride (SiOxNy) and silicon oxide (SiOx), which is more flexible than silicon nitride, is disposed inside the barrier layer. Since the above-mentioned barrier layer is laminated on the stress relaxation layer, this stress relaxation layer absorbs residual stress associated with the formation of the barrier layer compared to a single layer of silicon nitride barrier layer. As a result, the barrier layer can be formed relatively thick. In addition, since silicon nitride oxide and silicon oxide constituting the stress relaxation layer have a smaller residual stress accompanying the film formation than the silicon nitride film constituting the barrier layer, the layer thickness can be made thicker than the barrier layer. Thus, even when the barrier layer is formed thin, the physical strength can be improved. That is, by providing a stress relaxation layer on the inner side (substrate side) of the barrier layer and simply laminating the barrier layer on the stress relaxation layer, it is possible to improve the physical strength against impacts and prevent the occurrence of cracks accompanying an increase in film thickness. This can be achieved synergistically, whereby the organic EL element can be protected from moisture and oxygen over a long period of time, thereby greatly improving the reliability.

  In this specification, the component constituting the barrier layer does not allow any compound other than silicon nitride, and amorphous silicon (unless drastically changing its characteristics, as long as it is mainly composed of silicon nitride) a-Si), a mixture of SiO2, etc. may be sufficient. The same applies to the stress relaxation layer.

  As described above, the configuration of the sealing film layer is not particularly limited except for a configuration in which a barrier layer is laminated on the outside of the stress relaxation layer. The first layer that directly covers the organic EL element with the stress relaxation layer. For example, a barrier layer made of silicon nitride that is disposed inside the stress relaxation layer and on which the stress relaxation layer is stacked is further included, and a barrier inside the stress relaxation layer is included. It is preferable that the layer is configured as a first layer that directly covers the organic EL element. The barrier layer disposed inside the stress relaxation layer may be a mixture as described above.

  That is, it is known that silicon nitride oxide and silicon oxide are inferior to silicon nitride in terms of moisture and oxygen permeability, and there is a concern that moisture and the like may enter from the edge of the stress relaxation layer over time. The Therefore, by directly covering the organic EL element with a barrier layer made of silicon nitride and laminating the stress relaxation layer on this barrier layer, the organic EL element can be surely sealed regardless of time. In addition, since the stress relaxation layer is laminated on the barrier layer, the residual stress generated by the formation of the barrier layer can be absorbed by the stress relaxation layer, and the disadvantages associated with the generation of the residual stress are suppressed as much as possible. be able to. When the barrier layer disposed on the inner side of the stress relaxation layer is formed to be relatively thin, the influence of residual stress is suppressed as much as possible while maintaining the sealing effect. be able to.

  The thickness of the barrier layer disposed outside the stress relaxation layer is set as appropriate, but is set within a range of 500 to 8000 mm from the viewpoint of effectively preventing the occurrence of pinholes and cracks. (Claim 3).

  The layer thickness of the stress relaxation film is not particularly limited. However, in order to effectively absorb the residual stress of the barrier layer, the maximum thickness of the barrier layer disposed outside the stress relaxation layer is used. On the other hand, it is preferably set to 2 to 10 times.

  The film formation method of each of the barrier layers and the stress relaxation layer is not particularly limited, and is formed by a plasma CVD (Chemical Vapor Deposition) method using a spin coating, a sputtering method, an ECR (Electron Cyclotron Resonance) method, or the like. However, in this plasma CVD method, in particular, the barrier layer and the stress relaxation layer are formed on the substrate by converting the source gas into a plasma by a magnetic field generated by a flat plate coil disposed opposite to the substrate. Preferably, it is formed by an inductively coupled plasma CVD method.

  If comprised in this way, the source gas plasmified by the flat plate coil can be accelerated in multiple directions, and is not opposed to the flat plate coil, for example, a reverse tapered portion of an organic EL element having a reverse tapered shape in cross section. Each layer can be reliably synthesized and grown up to a portion. Therefore, for example, the organic EL element can be reliably sealed as compared with the case where each layer is formed by a plasma CVD method in which a source gas is converted into plasma using parallel plate electrodes.

  Moreover, the inductively coupled plasma CVD method has a higher ion current density and plasma density than the parallel plate type plasma CVD method, so that the probability that the accelerated electrons collide with the source gas molecules is increased. As a result, the source gas molecules can be efficiently converted into plasma. Therefore, the ratio of gas molecules that have not been converted to plasma is reduced, the increase in the substrate temperature due to the collision of the gas molecules with the substrate is suppressed, and the organic EL element is effectively prevented from being damaged under a low temperature atmosphere. This film can be formed. Furthermore, according to the inductively coupled plasma CVD method, the distance between the plasma generation source and the substrate can be increased, thereby making it difficult to transfer heat to the substrate and generating an increase in the substrate temperature. can do. Therefore, since the film can be formed at a low temperature, damage to the organic EL element due to heat can be effectively prevented.

  As described above, when a silicon nitride film, a nitrided oxide film, or an oxide film is formed by plasma CVD, ammonia (NH3) or hydrogen gas (H2) is added to a silane-based gas (SiH4 or the like) as usual. In order to form a high-quality film, the barrier layer is formed by using a silane-based gas and a nitrogen gas as the raw material gas, and the stress relaxation layer is formed by the method described above. It is preferably formed by using silane-based gas, nitrogen gas and oxygen gas as source gas.

  That is, since the organic EL element is damaged by heat as described above, it is required that the film be formed at a low temperature (80 ° C. or lower) when the film is formed by such an inductively coupled plasma CVD method. Conventionally, when a silicon nitride film, a nitrided oxide film, or an oxide film is formed by inductively coupled plasma CVD, it is performed by introducing ammonia gas (NH3) or hydrogen gas (H2) into a silane-based gas. However, as the amount of hydrogen atoms increases, the amount of hydrogen ions in the plasma also increases, and the hydrogen ions collide with the substrate and the temperature of the substrate rises. Therefore, by configuring as described above, it is possible to form a high-quality film (layer) at a low temperature by reducing the amount of hydrogen ions that collide with the substrate, and the substrate based on the collision of hydrogen ions can be formed. Damage can be reduced.

  Moreover, the organic EL display panel according to the present invention is an organic EL display panel comprising a plurality of organic EL elements and a substrate on which these organic EL elements are mounted. It is sealed with the sealing film according to any one of the above (Claim 7).

  According to this invention, since the organic EL element can be reliably and long-term sealed by the sealing film, it is possible to effectively prevent the occurrence of a light emitting defect point, a so-called dark spot, and its expansion.

  On the other hand, the organic EL display panel manufacturing method according to the present invention is the organic EL display panel manufacturing method in which the organic EL display panel is manufactured by covering and sealing the organic EL element mounted on the substrate. An element sealing step of laminating a first barrier layer made of silicon nitride as a first layer on the element, and a stress relaxation layer made of at least one of silicon nitride oxide and silicon oxide as the second layer after the element sealing step A stress relaxation step of laminating on the barrier layer; and a barrier step of laminating a second barrier layer made of silicon nitride as the third layer on the stress relaxation layer after the stress relaxation step. (Claim 8).

  According to the present invention, the organic EL display panel, in particular, the organic EL element included in the panel can be reliably covered and sealed with the sealing film having the above configuration. Therefore, the organic EL display panel by the manufacturing method according to the present invention can effectively prevent the generation of dark spots over a long period of time.

  In this case, the apparatus used for this manufacturing method is not particularly limited, and for example, a spin coater, a sputtering apparatus, a plasma CVD apparatus or the like can be used. However, in the element sealing process, the stress relaxation process, and the barrier process, The first and second barrier layers and the stress are formed using an inductively coupled plasma CVD apparatus that forms a film on the substrate by converting the source gas into plasma by a magnetic field generated by a flat coil disposed opposite to the substrate. It is preferable to form a relaxation layer (claim 9).

  If comprised in this way, the source gas plasmified by the flat plate coil can be accelerated in multiple directions, and is not opposed to the flat plate coil, for example, a reverse tapered portion of an organic EL element having a reverse tapered shape in cross section. Each layer can be reliably synthesized and grown up to a portion. Therefore, for example, the organic EL element can be reliably sealed as compared with the case where each layer is formed by a plasma CVD apparatus that converts the raw material gas into plasma by an electric field. In addition, since the inorganic film is laminated in this manufacturing method, all the layers can be formed in one plasma CVD apparatus, specifically, the same processing chamber, and the process becomes simple.

  Furthermore, as described above, according to the inductively coupled plasma CVD apparatus, the ion current density and the plasma density are higher than those of the parallel plate type plasma CVD apparatus, so that the probability that the accelerated electrons collide with the source gas molecules. As a result, the source gas molecules can be efficiently converted into plasma. Therefore, the ratio of gas molecules that have not been converted to plasma is reduced, the increase in the substrate temperature due to the collision of the gas molecules with the substrate is suppressed, and the organic EL element is effectively prevented from being damaged under a low temperature atmosphere. This film can be formed. Furthermore, according to the inductively coupled plasma CVD method, the distance between the plasma generation source and the substrate can be increased, thereby making it difficult to transfer heat to the substrate and generating an increase in the substrate temperature. can do. Therefore, since the film can be formed at a low temperature, damage to the organic EL element due to heat can be effectively prevented.

  Further, when using an inductively coupled plasma CVD apparatus, the specific configuration is not particularly limited. In the element sealing process, the stress relaxation process, and the barrier process, the winding portion of the flat coil is It is preferable to use a plasma CVD apparatus which is formed in a substantially rectangular shape and in which the winding portions are arranged in parallel in a substantially same plane.

  That is, when forming this silicon nitride film or the like, it is necessary to adjust the thickness to a level that can prevent the occurrence of cracks due to residual stress accompanying this film formation and pinholes accompanying film formation. In order to achieve this adjustment, it is required to form a film with a uniform thickness over the entire substrate. In an inductively coupled plasma CVD apparatus, when the film thickness is uniform, the plasma distribution on the substrate is also required to be uniform, and in order to generate plasma uniformly in this way, the distribution of magnetic field strength is required. Is also required to be uniform. According to the conventional inductively coupled plasma CVD apparatus, most of the flat plate coil is formed by forming a metal wire in a substantially circular spiral shape from the center. When such a circular flat plate coil is used, The magnetic field strength is reduced or eliminated at the outer peripheral portion and the peripheral portion of the flat plate coil as compared with the central portion. On the substrate facing the outer peripheral portion and the peripheral portion, the magnetic field strength is generated corresponding to the central portion of the flat coil. The film is formed by the diffusion of the plasma, and therefore, the film thickness tends to be thinner than the central part of the coil on the substrate facing the outer peripheral part and the peripheral part of the coil.

  Therefore, with the configuration described above, the winding portion is formed in a substantially rectangular shape, so that the winding portion can be densely disposed facing the substrate, and the magnetic field strength is made relatively uniform. Thus, a uniform film thickness can be formed. In addition, since the winding portions with high magnetic field strength are laid out in the same plane (arranged in parallel), even when there is a portion where the magnetic field strength is low between the winding portions, the adjacent magnetic field strength is Since each of the plasmas generated by the plurality of high winding portions is diffused to form a film on a substrate having a low magnetic field strength, there is almost no difference in film thickness, and the film can be formed as uniformly as possible. In addition, since the film thickness can be uniformly formed regardless of the film formation area, a sealing film having a uniform film thickness can be formed even on a substrate having a relatively large area.

  In the element sealing step and the barrier step, the source gas is not particularly limited, but a silane-based gas and a nitrogen gas are used as the source gas, and in the stress relaxation step, a silane-based gas, nitrogen is used as the source gas. It is preferable to use gas and oxygen gas (claim 11).

  With this configuration, it is possible to form a high-quality film (layer) at a low temperature by reducing the amount of hydrogen ions that collide with the substrate, and reduce damage to the substrate due to collisions of hydrogen ions. It becomes possible to do.

  In this case, various conditions in forming each layer (first and second barrier layers, stress relaxation layer) are not particularly limited. For example, the layers are laminated in the element sealing step, the stress relaxation step, and the barrier step. Preferably, the first and second barrier layers and the stress relaxation layer are formed in the plasma CVD apparatus under a pressure of 0.1 Pa or less.

  With this configuration, since the film is formed in a high vacuum atmosphere having a pressure of 0.1 Pa or less, silicon nitride or the like can be efficiently deposited on the substrate.

  According to the invention with the above configuration, the organic EL element can be reliably sealed, and thereby the element can be effectively protected from moisture and oxygen, and the reliability in the organic EL display panel can be improved. There is. In addition, by providing a stress relaxation layer on the inner side (substrate side) of the barrier layer and simply laminating the barrier layer on the stress relaxation layer, it is possible to improve the physical strength against impacts and prevent the occurrence of cracks accompanying an increase in film thickness. This can be achieved synergistically, whereby the organic EL element can be protected from moisture and oxygen over a long period of time, and this has the advantage that the reliability is dramatically improved.

  A preferred embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a cross-sectional view showing an outline of an organic EL display panel sealed with a sealing film of an organic EL element of the present invention. FIG. 2 is an enlarged cross-sectional view showing an organic EL element covered and sealed with a sealing film.

  The organic EL display panel 2 sealed by the sealing film 5 of the present embodiment includes a transparent substrate 3, one or a plurality of organic EL elements 4 mounted on the transparent substrate 3, and the organic EL elements 4. And a sealing film 5 for covering and sealing one surface side of the transparent substrate 3 including the organic EL element 4 to emit light when a predetermined voltage is applied to the organic EL element 4.

  The transparent substrate 3 is a plate-like body that can transmit light in the visible region with a predetermined transmittance (90% in the present embodiment) and has a smooth surface. In this embodiment, a transparent glass plate is used. It is done. The material used for the transparent substrate 3 is not limited to transparent glass, but may be, for example, translucent glass, or synthetic resin such as polycarbonate or PET (polyethylene terephthalate). A flexible organic EL display panel can be manufactured by using a flexible resin such as PET among synthetic resins. However, when a synthetic resin is used as the material, the surface of the substrate 3 is subjected to a barrier treatment by, for example, the sealing film 5 so that moisture and oxygen do not pass through the transparent substrate 3.

  The organic EL element 4 is configured by sandwiching an organic material between electrodes, and specifically, a transparent electrode 6 (anode) formed on the transparent substrate 3 and an organic layer laminated on the transparent electrode 6. A layer 8 and a metal electrode 7 (cathode) laminated on the organic layer 8 are provided.

  The transparent electrode 6 is preferably made of an electrically conductive compound such as a metal or alloy having a high hole injection capability and a work function higher than that of the metal electrode 7. For example, the transparent electrode 6 is made of a conductive material such as ITO (indium oxide doped with tin), ATO (tin doped with antimony oxide), AZO (zinc monoxide doped with aluminum), gold, tin oxide or the like. It is formed by forming a film on the transparent substrate 3 by sputtering or the like. Although the film thickness of the transparent electrode 6 is not specifically limited, Usually, it forms in 10 nm-3 micrometers. On the other hand, the metal electrode 7 is preferably an electrically conductive compound such as a metal or alloy having a low work function (for example, 4.0 ev or less). For example, the metal electrode 7 is made of a metal such as aluminum, sodium, magnesium, indium, or titanium, or a conductive material such as an aluminum alloy or an indium alloy, on the organic layer 8 by vapor deposition or sputtering. The film thickness of the metal electrode 7 is also formed to be 10 nm to 3 μm, similar to the film thickness of the transparent electrode 6.

  The organic layer 8 is known to have a single-layer structure or a multi-layer structure (for example, two or three layers). Here, a three-layer structure will be described. That is, the organic layer 8 includes a light emitting layer 10 that emits light by recombination of holes and electrons, a hole transport layer 9 that contacts the transparent electrode 6 and injects holes into the light emitting layer 10, and a metal electrode 7. And an electron transport layer 11 for injecting electrons into the light emitting layer 10. The material constituting the organic layer 8 may be either a low molecular material or a high molecular material.

  The light emitting layer 10 is made of a low molecular fluorescent dye, a fluorescent polymer, a metal complex, or the like. The light-emitting layer 10 can inject holes from the anode side and electrons from the cathode side when an electric field is applied, can move the injected charge and provide a field where holes and electrons recombine, and has high luminous efficiency. In view of convenience during production, those having good film forming properties are preferably used. For example, known materials such as aluminum quinolinol complex (Alq3) and diamines are used. The hole transport layer 9 preferably has a high carrier transport performance, is transparent, and has a good film forming property. For example, a known material such as copper phthalocyanine (CuPc), a triazole derivative, an oxadiazole derivative, or TPD is used. The electron transport layer 11 is made of a known material such as an anthraquinodimethane derivative, a diphenylquinone derivative, or an oxadiazole derivative.

  The sealing film 5 includes a barrier layer made of silicon nitride (SiNx: for example Si3N4), and a stress relaxation layer made of silicon oxynitride (SiOxNy: for example SiON) which is disposed inside the barrier layer and on which the barrier layer is laminated. And a plurality of layers including In the present embodiment, as shown in FIG. 3, the sealing film 5 has a stress relaxation layer 52 made of silicon nitride oxide interposed between the first and second barrier layers 53 and 51 made of silicon nitride (SiNx). It is formed in a three-layer structure.

  The first barrier layer 53 is provided to reliably prevent intrusion of moisture and oxygen through the stress relaxation layer 52 and is disposed inside the stress relaxation layer 52 and directly covers the organic EL element 4. It is configured as a first layer. Specifically, the first barrier layer 53 is formed on the transparent substrate 3 in a region wider than the region where the organic EL element 4 is mounted by silicon nitride (SiNx) by plasma CVD (Chemical Vapor Deposition). Is deposited. In film formation by this plasma CVD method, an inductively coupled plasma CVD apparatus 15 described later is used, and silane gas (SiH 4) and nitrogen gas (N 2) are used as material gases. A film forming method by this plasma CVD method will be described later.

  The first barrier layer 53 is formed thinner than the other layers 51 and 52, but thicker than the case where a single layer of silicon nitride is provided. be able to. That is, in the case where the layer made of silicon nitride is provided as a single layer, there is a possibility that cracking may occur due to the residual stress (internal stress) if the layer is formed thick. However, in this embodiment, since the stress relaxation layer 52 is laminated on the first barrier layer 53, the strength against the crack is improved by the stress relaxation layer 52. Therefore, the film thickness is compared with the normal case. It can be formed thick. Specifically, the upper limit of the layer thickness t1 of the first barrier layer 53 is set to 2500 mm or less, preferably 1500 mm or less. On the other hand, if the layer thickness t1 of the first barrier layer 53 made of silicon nitride is formed too thin, there is a concern that so-called pinholes may occur due to poor film formation. Therefore, the lower limit of the layer thickness t1 of the first barrier layer 53 is set to 500 mm or more, preferably 600 mm or more. In the present embodiment, the layer thickness t1 of the first barrier layer 53 is set to about 1000 mm on average within the range of 800 mm to 1200 mm.

  The stress relaxation layer 52 is laminated on the first barrier layer 53. The stress relieving layer 52 is provided to relieve the residual stress generated in the layer made of silicon nitride, and therefore is more flexible than the first and second barrier layers 53 and 51 made of silicon nitride. It is composed of silicon (SiOxNy), silicon oxide (SiOx: for example, SiO2), or a mixture thereof. In this embodiment, silicon nitride oxide having low moisture and oxygen permeability is used, although it is inferior to silicon oxide in terms of flexibility. In this embodiment, the stress relaxation layer 52 adopts a single layer structure made of silicon oxynitride, but a single layer structure made of silicon oxide or a layer made of silicon oxide is interposed between layers made of silicon oxynitride. For example, a plurality of layers made of silicon nitride oxide or silicon oxide may be used.

  Further, in order to effectively absorb the residual stress of the first and second barrier layers 53 and 51, the stress relaxation layer 52 has a layer thickness t2 of the second barrier layer 51, particularly the second barrier layer. Among the 51 layer thicknesses, it is set within a range of 2 to 10 times the maximum layer thickness. Specifically, the layer thickness t2 of the stress relaxation layer 52 is preferably set in the range of 1000 to 10000 and more preferably in the range of 3000 to 9000. In the present embodiment, the thickness t2 of the stress relaxation layer 52 is set to about 8000 mm on average within the range of 7700 mm to 8300 mm.

  Thus, since the stress relaxation layer 52 is formed relatively thick, various particles adhering to the transparent substrate 3 can be effectively sealed in the stress relaxation layer 52. Therefore, for example, particles adhering to the transparent substrate 3 cannot be filled by film formation, and it is possible to effectively prevent moisture and oxygen from entering through the periphery of the particles.

  The second barrier layer 51 is laminated on the stress relaxation layer 52. The second barrier layer 51 can be formed thicker than the first barrier layer 53. That is, since the second barrier layer 51 is laminated on the stress relaxation layer 52 made of silicon nitride oxide which is softer than silicon nitride, the stress relaxation layer 52 is formed according to the residual stress of the second barrier layer 51. It slightly expands and contracts, which makes it difficult for cracks based on residual stress to occur. Specifically, the upper limit of the layer thickness t3 of the second barrier layer 51 is set to 8000 mm or less, preferably 5000 mm or less. On the other hand, if the layer thickness t1 of the first barrier layer 53 made of silicon nitride is formed too thin, there is a concern that so-called pinholes may occur due to a decrease in physical strength such as external impact and film formation defects. Therefore, the lower limit of the layer thickness t3 of the second barrier layer 51 is set to 500 mm or more, preferably 800 mm or more. In the present embodiment, the layer thickness t3 of the second barrier layer 51 is set to about 2000 mm on average within the range of 1500 mm to 2500 mm.

  Although not shown, the second barrier layer 51 is formed wider than the formation region of the first barrier layer 53 and the stress relaxation layer 52 at the outer edge portion of the formation region, whereby the first barrier layer 53 is formed. And the edge part of the stress relaxation layer 52 is sealed.

  After sealing the organic EL display panel 2 with the sealing film 5 having the above-described configuration and confirming the light emission state of the organic EL display panel 2, the panel 2 is placed in an environment of 65 ° C. and 90% humidity for 60 days. Stored for about (1440 hours). Thereafter, the light emission state of the organic EL display panel 2 was confirmed again. As a result, so-called dark spots were hardly seen and a good light emission state was shown. As described above, according to the sealing film 5 configured as described above, the barrier layer 51 made of silicon nitride (SiNx) having a very low moisture and oxygen permeability is used as the sealing film for covering and sealing the organic EL element 4. , 53, the organic EL element 4 can be surely sealed, thereby effectively protecting the element 4 from moisture and oxygen and improving its reliability.

  Here, when the barrier layers 51 and 53 made of silicon nitride are formed, there is a problem in coexistence of improvement in physical strength against impact and the like and prevention of crack generation accompanying an increase in film thickness. A stress relaxation layer 52 made of silicon oxynitride, which is softer than silicon nitride, is disposed outside or inside the second barrier layer 51, and this stress relaxation layer 52 is laminated on the first barrier layer 53, or Since the second barrier layer 51 is laminated on the stress relaxation layer 52, the barrier layers 53, 51 of the stress relaxation layer 52 are compared with those in which the barrier layer made of silicon nitride is provided as a single layer. Residual stress accompanying the film formation can be absorbed, whereby the first and second barrier layers 53 and 51 can be formed relatively thick while preventing the generation of cracks. Moreover, since the silicon oxynitride constituting the stress relaxation layer 52 has a smaller residual stress accompanying the film formation than the silicon nitride film constituting the barrier layer, the layer thickness is thicker than that of the first and second barrier layers 53 and 51. Accordingly, even if the barrier layers 51 and 53 are formed thin, the physical strength of the sealing film 5 can be improved. Furthermore, the stress relaxation layer 52 made of silicon nitride oxide has a higher deposition rate in film formation than the first and second barrier layers 53 and 51 made of silicon nitride, and therefore the sealing film 5 having a desired physical strength is formed. It can be formed quickly.

  Here, an inductively coupled plasma CVD apparatus 15 for forming the sealing film 5 and a film forming and sealing method (manufacturing method of the organic EL display panel 2) using the apparatus 15 will be described. First, after describing the inductively coupled plasma CVD apparatus 15, a film forming method will be described.

  FIG. 4 is a front sectional view showing an outline of the inductively coupled plasma CVD apparatus of the present embodiment, and FIG. 5 is a plan view showing a state in which a lid of a processing container described later is opened. The plasma CVD apparatus 15 is an inductively coupled CVD apparatus that excites plasma by an induction coil 18 and is configured to perform a plasma CVD method in a room temperature atmosphere of approximately 50 ° C. or lower (for example, 40 ° C.).

  The plasma CVD apparatus 15 includes a processing container 16 that houses an organic EL display panel (hereinafter referred to as a “pre-sealing panel”) 2a before sealing with the sealing film 5, and a sealing container disposed in the processing container 16. A substrate installation member 17 for installing the pre-stop panel 2a and the like, a flat plate induction coil 18 disposed above the processing container 16 and generating a magnetic field in the processing container 16, and a gas disposed in the processing container 16 A gas supply unit 19 that supplies a predetermined source gas from the supply sources 30 to 32 into the container 16 and a vacuum pump 20 that puts the inside of the processing container 16 into a high vacuum state at a predetermined pressure are provided. The supply unit 19 is configured so that the source gas is uniformly supplied to the pre-sealing panel 2a installed on the substrate installation member 17, and below the pre-sealing panel 2a installed on the substrate installation member 17. Located on the side Rectifying plate 21 is provided to rectify the gas is evacuated by the vacuum pump 20 Te. The plasma CVD apparatus 15 introduces a raw material gas into the processing vessel 16 from the gas supply unit 19, converts the raw material gas into plasma by the induction coil 18, and the plasmaized raw material is placed on the substrate placement member 17. The organic EL display panel 2 is manufactured by depositing on the panel 2a before sealing, thereby forming the sealing film 5 and sealing the organic EL element 4 on the panel 2a before sealing.

  Specifically, the processing container 16 performs a film forming process on the pre-sealing panel 2a inside a substantially vacuum. The processing container 16 has a container body 61 that is formed in a size that can accommodate the pre-sealing panel 2a and opens upward, and a lid 62 that closes the upper opening, and is a rectangular parallelepiped box as a whole. I am making a body. As shown in FIGS. 4 and 5, the container main body 61 is provided with an exhaust port 61 a at substantially the center of the bottom wall portion thereof, and is connected to the vacuum pump 20 through the exhaust pipe 22. One of the peripheral wall portions erected from the periphery of the bottom wall portion is provided with a horizontally long panel insertion port 61b, and the CVD device 15 is juxtaposed with the CVD device 15 through the panel insertion port 61b. 23, and the panel insertion opening 61b is provided with an opening / closing lid 63 capable of airtightly closing the insertion opening 61b. Then, the opening / closing lid 63 is opened, and the pre-sealing panel 2a is set from the panel setting device 23 to the board installation member 17 through the panel insertion opening 61b, and the opening / closing lid 63 is closed to close the panel 2a before sealing. A plasma CVD process is performed to manufacture the organic EL display panel 2. Thereafter, the opening / closing lid 63 is opened again, and the organic EL display panel 2 is transported to the panel setting device 23 through the panel insertion opening 61b.

  The lid body 62 has a through hole formed in a central region thereof, and a transmission window 62a is fitted in the through hole in an airtight state. An induction coil 18 is disposed on the upper surface of the transmission window 62a, and a magnetic field generated by the induction coil 18 is generated in the processing container 16 through the transmission window 62a. A rectangular frame-shaped gas supply unit 19 is fixed to the lower surface of the lid 62.

  On the other hand, the board installation member 17 includes an installation main body 171, a plurality of installation protrusions 172 protruding upward from the main body 171, and a plate-like installation plate whose lower surface is supported by the tip of the installation protrusion 172. And a panel (such as the organic EL display panel 2 or the pre-sealing panel 2a) is placed on the installation plate portion 173. A rectifying plate 21 is disposed between the installation main body 171 and the installation plate 173. As described above, the rectifying plate 21 rectifies the gas exhausted by the vacuum pump 20, and forms a flat body in which a large number of through holes 210 are arranged in a predetermined pattern (see FIG. 6). ). In particular, in this embodiment, the rectifying plate 21 constitutes a flat plate-like body that can accommodate the panels 2 and 2a, and accommodates the pre-sealing panel 2a together with the installation plate portion 173 during the plasma CVD process. By surrounding the panel 2a, the source gas is configured to easily convect around the pre-sealing panel 2a. As will be described later, the rectifying plate 21 is configured to move relative to the substrate installation member 17, but the installation protrusion 172 of the substrate installation member 17 includes the rectifying plate including the relative movement. The interference avoidance hole 211 is provided so that it may not interfere with 21 (refer FIG. 6).

  The board installation member 17 and the rectifying plate 21 are configured to be movable up and down by an elevating mechanism 24 described below. That is, the elevating mechanism 24 includes a pair of left and right drive shafts 241 whose longitudinal ends are pivotally supported at predetermined locations of the container body 61, and a drive motor (not shown) that rotationally drives the drive shaft 241 in the forward and reverse directions. And a pair of oscillating members 242 that are fixed to the drive shaft 241 and oscillate with forward and reverse rotation of the drive shaft 241, and the substrate installation member 17 is pivotally supported in the middle part of each oscillating member 242. In addition, the rectifying plate 21 is pivotally supported at the tip (upper end) portion of the swing member 242.

  Therefore, as shown in FIG. 7, the board installation member 17 and the current plate 21 both move up and down while changing the relative height in accordance with the swing of the swing member 242 in the lift mechanism 24. It has been. In other words, the elevating mechanism 24 tilts the swinging member 242 and separates the relative positions of the installation plate portion 173 and the rectifying plate 21 so that the panels 2 and 2a can be easily set and removed (see FIG. 7). (Shown by a solid line), the swinging member 242 is caused around the drive shaft 241 from this set posture to bring the relative position between the installation plate portion 173 and the rectifying plate 21 close, and the upper edge of the rectifying plate 21 is made to be A processing posture (shown by a solid line in FIG. 4 or indicated by a two-dot chain line in FIG. 7) that facilitates convection of gas around the panels 2 and 2a by being brought into contact with the lower surface is configured to be switchable. Note that the relative height between the substrate installation member 17 and the rectifying plate 21 is changed due to the swing of the swing member 242 due to the mounting position of the swing member 242 of each of the members 17 and 21. That is, if the swinging member 242 is attached to the distal end side away from the drive shaft 241, the elevation height becomes higher than that attached to the middle part thereof.

  In the setting posture of the elevating mechanism 24, both the substrate installation member 17 and the current plate 21 are at the lower limit position located below the panel insertion opening 61 b of the container body 61, and the panels 2 and 2 a are mounted on the installation plate portion 173. And the removal of the panels 2 and 2a from the installation plate portion 173 can be easily performed. On the other hand, in the processing posture, the substrate installation member 17, in other words, the panels 2 and 2 a placed on the installation plate portion 173 are located substantially opposite to the gas supply unit 19 and the transmission window 62 a in the height direction. It is set so that it is in a position (for example, a position of about 200 mm) that is relatively separated from the lower surface. That is, in the parallel plate type CVD apparatus, the distance from the transmission window 62a to the panel is provided at a relatively close position of about 50 mm, but the apparatus of this embodiment is an inductively coupled plasma CVD apparatus. As described above, the distance from the transmission window 62a to the installation plate portion 173 can be provided at a relatively separated position. Therefore, the panels 2 and 2a can be arranged at a distance away from the generated plasma, and the temperature rise of the panels 2 and 2a due to the plasma can be suppressed, whereby the organic EL element 4 associated with the temperature rise can be suppressed. Damage can be effectively prevented. In addition, since the source gas supplied from the gas supply unit 19 by the rectifying plate 21 convects around the panels 2 and 2a, the sealing film 5 having a uniform film thickness can be formed, and pinholes are effectively generated. In addition, the film thickness can be easily adjusted due to residual stress.

  The induction coil 18 is connected to a high frequency power source 26 via an impedance matching unit 25. The induction coil 18 is a flat-plate coil in which a conductive wire such as metal is wound in substantially the same plane. In particular, in the present embodiment, the winding portions 180 are formed in a substantially rectangular shape, and the winding portions 180 are arranged side by side in a densely packed state in a substantially same plane. That is, the induction coil 18 has a winding portion 180 formed by winding the conducting wire once in a substantially rectangular shape (the rotation direction is not particularly limited but counterclockwise in the illustrated example), and extends from the winding portion 180. And a branch portion 181 connected to the impedance matching unit 25 by collecting the conductive wires, and configured to generate a magnetic field in a wider area than the panels 2 and 2a installed on the board installation member 17. The arrangement pattern of the winding portions 180 is not particularly limited, but here, the rectangular winding portions 180 are arranged at predetermined intervals in the short side direction.

  As described above, a plurality of winding portions 180 are provided in the induction coil 18 and each winding portion 180 is formed in a substantially rectangular shape, and the winding portions 180 are arranged side by side in the same plane. The magnetic field can be generated relatively uniformly at the same time, and the peak of the magnetic field strength can be provided close to each other. In 2a, a film can be formed with a uniform film thickness by plasma.

  A plurality of gas supply units 19 are provided depending on the type of gas to be supplied. In the present embodiment, three types of gas are configured to be supplied into the processing container 16 through two gas paths. Therefore, the gas supply unit 19 is attached to the lid 62 in a state where two gas supply units 19 are stacked one on the other. ing. Note that these two types of gas supply units 19a and 19b have substantially the same configuration except for the type of gas to be introduced and the number of gas ejection tubes 192 to be described later. The gas supply unit 19b will be mainly described.

  The gas supply unit 19 of the present embodiment is provided in a state of being substantially opposed to the panels 2 and 2a installed on the substrate installation member 17, and gas ejection holes 195 are provided in a scattered manner.

  That is, the gas supply unit 19 is made of a chemically stable material such as quartz or ceramics such as alumina. As shown in FIGS. 5 and 6, the gas supply unit 19 includes a pair of front and rear headers 191 extending in the left-right direction, a plurality of gas ejection tubes 192 whose both ends are connected to the header 191, and a pair of And a connecting member 193 that connects both ends in the longitudinal direction of the header 191 to form a substantially rectangular frame-like body in plan view. The header 191 has a gas flow passage 191a formed therein along the longitudinal direction, and the end of the gas ejection tube 192 is airtightly held in a state where the gas flow passage 191a and the gas ejection tube 192 communicate with each other. The gas flow path 191a is connected to gas supply sources 31 to 32 shown in FIG. 4 via a gas flow path 62b provided in the lid 62. The distance between the headers 191 is slightly shorter in the gas supply unit 19a disposed on the upper side than that disposed on the lower side.

  A gas flow passage 62b provided in the lid 62 is provided with an exhaust port 62c that opens into the processing container 16, and a switching valve that switches the gas flow passage 62b between the exhaust port 62c side and the gas supply unit 19 side. 621 is disposed. The exhaust port 62c is provided to quickly exhaust the gas remaining in the gas supply unit 19 and the gas flow passage 62b after the plasma CVD process, and switches the switching valve 621 after the plasma process to open (FIG. 6). (State indicated by a solid line). In the plasma CVD process, the switching valve 621 is configured to close the exhaust port 62c as shown by a two-dot chain line in FIG. 6, and the gas supplied from the gas supply sources 31 to 32 is supplied from the switching valve 621. The gas is supplied to the gas supply unit 19 through the surroundings.

  The gas ejection tube 192 is a thin tube member designed to have a diameter of approximately 6 mm, and gas ejection holes 195 for ejecting the raw material gas into the processing container 16 are provided uniformly at predetermined intervals along the longitudinal direction. The gas ejection holes 195 are open in the horizontal direction. Further, the gas ejection holes 195 are arranged in a staggered arrangement with respect to the ejection ports 195 in the other gas supply unit 19 here. Furthermore, the diameter of the gas ejection hole 195 is very small, and is designed to be 0.1 mm, for example.

  Here, the source gas introduced into these gas supply units 19a and 19b will be described. In order to form the sealing film 5 in the plasma CVD apparatus 15, silane gas (SiH 4), nitrogen gas (N 2), and oxygen gas (O 2) are sealed in each of the gas supply sources 30 to 32. In forming the first barrier layer 53, silane gas and nitrogen gas are introduced from the gas supply sources 30 and 31 into the gas supply unit 19 a and supplied into the processing container 16 through the gas ejection holes 195. ing. When the stress relaxation layer 52 is formed in this state, in addition to the silane gas and the nitrogen gas being introduced from the gas supply unit 19a, the oxygen gas is introduced from the gas supply source 32 to the gas supply unit 19b. It is configured. Finally, in order to form the second barrier layer 51, the supply of the oxygen gas introduced into the gas supply unit 19b is stopped, and only the silane gas and the nitrogen gas are introduced into the processing container 16. Yes. Various controls in the device 15 such as the gas supply amount and supply timing are performed by a control means (not shown) composed of a CPU, a ROM, etc., and based on setting conditions from an input means (not shown), The control means is configured to execute various controls.

  That is, when the first and second barrier layers 53 and 51 are formed by the control means, the silane gas is supplied into the processing container 16 at a rate of 30 sccm and the nitrogen gas at a rate of 300 sccm, and the stress relaxation layer 52 is formed. Sometimes, silane gas, nitrogen gas, and oxygen gas are supplied into the processing vessel 16 at a rate of 30 sccm, 300 sccm, and 50 sccm, respectively.

  Here, in this apparatus 15, when forming the first and second barrier layers 53, 51, that is, the silicon nitride film, ammonia gas (NH 3) or hydrogen gas (H 2) is not introduced, but nitrogen gas ( N2) is introduced. This is because, when hydrogen atoms are used as the source gas, it is easy to excite, but if the amount of hydrogen atoms is excessive, the ambient temperature rises and adversely affects the panels 2 and 2a. Therefore, by using nitrogen gas as the source gas, it is possible to suppress the temperature rise and effectively prevent the organic EL element 4 from being damaged due to this temperature rise.

  On the other hand, the vacuum pump 20 is connected to the processing container 16 through the exhaust pipe 22 as described above. As the vacuum pump 20, a high-power pump (for example, a pump having a performance of 2300 l / sec) is used, and is configured to be set to a pressure of 0.1 Pa or less in a state where a raw material gas is injected. The exhaust pipe 22 is provided with a gate valve 28 for adjusting the degree of vacuum in the processing container 16. The gate valve 28 is also controlled by the control means based on an atmospheric pressure sensor (not shown) provided in the processing container 16. The vacuum pump 20 is connected to an exhaust pipe (not shown).

  Next, a film forming method for forming the sealing film 5 using the plasma CVD apparatus 15 having the above configuration will be described.

  First, the pre-sealing panel 2 a is installed on the substrate installation member 17 through the panel insertion opening 61 b by the panel setting device 23. At this time, the elevating mechanism 24 is in a set posture in which the swing member 242 is lying down. Next, the opening / closing lid 63 is closed in an airtight state, and the drive shaft 241 is driven to rotate counterclockwise in FIG. 4, thereby causing the swinging member 242 to rotate around the drive shaft 241. As the swinging member 242 causes the substrate mounting member 17 and the rectifying plate 21 to rise in the direction approaching the gas supply unit 19, the upper edge of the peripheral wall portion of the rectifying plate 21 extends to the header 191 of the gas supply unit 19. The lift mechanism 24 is brought into contact with the processing posture. At this time, the pre-sealing panel 2a placed on the installation plate portion 173 and the bottom wall portion of the rectifying plate 21 move relative to each other so that the pre-sealing panel 2a is completely within the rectifying plate 21. It is in a contained state. Then, by driving the vacuum pump 20 and adjusting the gate valve 28, the inside of the processing container 16 is brought into a high vacuum state of 0.1 Pa or less to complete the film forming preparation process.

  When this film forming preparation process is completed, the film forming process is started. In this film forming process, an element sealing process for forming the first barrier layer 53 is first performed. More specifically, a bias potential is applied to the induction coil 18 to generate a magnetic field, and an on-off valve (not shown) provided upstream of the gas supply sources 30 and 31 is opened to supply the gas supply unit 19 with silane gas and nitrogen. A gas is supplied, and a raw material gas is supplied from the gas supply unit 19 through the gas ejection hole 195 into the processing container 16 for a predetermined time. Specifically, silane gas is supplied at a rate of 30-50 sccm and nitrogen gas is supplied at a rate of 300-500 sccm for 2-5 minutes. In the processing container 16, silane gas and nitrogen gas are turned into plasma, and the rectified plate 21 forms the plasmaized silicon (Si) and nitrogen (N) around the pre-sealing panel 2 a. Then, the plasmaized silicon (Si) and nitrogen (N) are deposited as a silicon nitride film on the surface of the panel 2 a to form the first barrier layer 53. The silicon nitride film is formed along the shape of the organic EL element 4 at a portion where the organic EL element 4 is present. Accordingly, the silicon nitride is deposited on the base end portion of the reverse taper type organic EL element 4 and the first layer is formed. A barrier layer 53 is formed.

  The source gas is led to the exhaust pipe 22 through the through hole 210 of the rectifying plate 21 and exhausted by the vacuum pump 20. By this rectifying plate 21, the gas flows symmetrically on the pre-sealing panel 2a, and is rectified into a gas flow for forming a uniform film thickness while effectively preventing turbulent flow.

  After the element sealing step for forming the first barrier layer 53, the process proceeds to a stress relaxation step. In this stress relaxation step, the source gas may be continuously supplied and the magnetic field may be continuously formed after the source gas is supplied in the element sealing step. After the formation is stopped, three kinds of source gases are newly supplied and a magnetic field is formed. That is, the magnetic field generated by the induction coil 18 is formed again, and silane gas and nitrogen gas are supplied from the gas supply sources 30 and 31 into the processing container 16 through the gas ejection holes 195 of the gas supply unit 19a, and gas is supplied from the gas supply source 32 Oxygen gas is supplied into the processing container 16 through the gas ejection hole 195 of the part 19b for a predetermined time. Specifically, silane gas is supplied at a rate of 30 sccm, nitrogen gas is supplied at a rate of 300 sccm, and oxygen gas is supplied at a rate of 50 sccm for 2 to 10 minutes.

  In the processing container 16, silane gas, nitrogen gas, and oxygen gas are turned into plasma, and the rectified plate 21 turns this plasmad silicon (Si), nitrogen (N), and oxygen (O) around the pre-sealing panel 2 a. It has become. The plasmaized silicon (Si), nitrogen (N), and oxygen (O) are deposited as a silicon oxynitride film on the surface of the first barrier layer 53 to form the stress relaxation layer 52. The film formation rate of the stress relaxation layer 52 is faster than the film formation rate of the silicon nitride film, so that even when the film thickness is thicker than the first barrier layer 53, the film can be formed quickly. In addition, the stress relaxation layer 52 has a thickness of 8000 mm and is thicker than 1000 mm of the first barrier layer 53, and even when fine dust is attached to the panel 2a before sealing, the dust can be enclosed. For this reason, generation | occurrence | production of the pinhole resulting from this fine dust can be prevented effectively, and the reliability with respect to sealing can be improved.

  Next, a second barrier layer 51 is formed in a barrier process to securely seal the organic EL element 4. In this barrier process, the source gas may be continuously supplied to the source gas in the stress relaxation process and the magnetic field may be continuously formed. After stopping, two kinds of source gases are newly supplied and a magnetic field is formed. That is, the magnetic field generated by the induction coil 18 is formed again, and an open / close valve (not shown) provided upstream of the gas supply sources 30 and 31 is opened to supply silane gas and nitrogen gas to the gas supply unit 19. A raw material gas is supplied from 19 to the processing vessel 16 through a gas ejection hole 195 for a predetermined amount and time. Specifically, silane gas is supplied at a rate of 30-50 sccm and nitrogen gas is supplied at a rate of 300-500 sccm for 2-5 minutes.

  In the processing container 16, silane gas and nitrogen gas are turned into plasma, and the rectified plate 21 forms the plasmaized silicon (Si) and nitrogen (N) around the pre-sealing panel 2 a. Then, the plasmaized silicon (Si) and nitrogen (N) are deposited as a silicon nitride film on the surface of the stress relaxation layer 52 to form the second barrier layer 51. The supply time of the source gas in this barrier process is set longer than the supply time of the source gas in the element sealing process. Therefore, the second barrier layer 51 is formed thicker than the first barrier layer 53.

  Thus, the first barrier layer 53, the stress relaxation layer 52, and the second barrier layer 51 are formed to form the sealing film 5 on the pre-sealing panel 2a, thereby forming the organic EL display panel 2. And after completion | finish of this barrier process, while stopping supply of a voltage to the induction coil 18, the vacuum pump 20 is stopped and the rocking | fluctuation member 242 of the raising / lowering mechanism 24 is fallen down, and it transfers to a setting attitude | position from a process attitude | position. Next, the opening / closing lid 63 is opened, and the organic EL display panel 2 is taken out from the installation plate 173 in the set posture to the panel setting device 23 through the panel insertion opening 61b.

  According to the organic EL display panel 2, since the organic EL element 4 can be reliably and long-term sealed by the sealing film 5, it is possible to effectively prevent the occurrence of light emission defect points, so-called dark spots, and their expansion. can do.

  Further, according to the method for manufacturing the organic EL display panel 2, the organic EL display panel 2, particularly the organic EL element 4 included in the panel 2 can be reliably covered and sealed with the sealing film 5.

  In addition, the specific structure of the sealing film 5 of this invention, the organic electroluminescent display panel 2, and its manufacturing method is not limited to the said embodiment, A various change is possible. Other embodiments are described below.

  (1) In the above-described embodiment, the first barrier layer 53 is formed to be thinner than the second barrier layer 51 in the sealing film 5, but each layer thickness may be the same. Further, the first barrier layer 53 may be formed thick.

  However, although the first barrier layer 53 partially absorbs the residual stress by the stress relaxation layer 52, it is inappropriate to form the first barrier layer 53 thick due to its nature. Therefore, from the viewpoint of securely sealing the organic EL element 4, As in the above embodiment, it is preferable that the second barrier layer 51 is formed to be thicker than the first barrier layer 53.

  (2) In the plasma CVD apparatus 15 in the above embodiment, the shape of the induction coil 18 is not particularly limited, and may be, for example, a spiral coil employed in a conventional apparatus. Moreover, as shown in FIG. 9, the induction coil 18a may form the winding part 180a by bending a single conducting wire in a meandering manner. Furthermore, the winding direction of the winding part 180 does not have to be the same direction, and may be alternately wound in the opposite direction.

  However, since the film pressure can be made uniform by forming a uniform magnetic field, the winding portion 180 of the flat coil 18 is formed in a substantially rectangular shape, and the winding portion 180 is substantially in the same plane. Are preferably arranged side by side.

  (3) In the above embodiment, the opening direction, the arrangement position, the size, the shape, and the like of the gas ejection hole 195 are not particularly limited, and the raw material gas to be ejected is uniformly filled in the processing vessel 16. It is designed appropriately. For example, the gas ejection holes 195 may be provided densely in a substantially central portion of the region facing the panels 2 and 2a and roughly provided in the outer peripheral portion.

It is a conceptual diagram which shows one Embodiment of the organic electroluminescent display panel of this invention. It is sectional drawing which expands and shows the sealing state of the organic EL element of the panel. It is sectional drawing which shows one Embodiment of the sealing film of this invention. It is front sectional drawing which shows the plasma CVD apparatus for forming this sealing film. It is a top view which shows the processing container of the same CVD apparatus in the state which opened the cover body. It is side surface sectional drawing which expands and shows partially the CVD apparatus of FIG. It is explanatory drawing which shows the effect | action of the raising / lowering apparatus of the same CVD apparatus. It is a schematic perspective view which shows the induction coil of the same CVD apparatus. It is a schematic perspective view which shows the modification of the induction coil.

Explanation of symbols

DESCRIPTION OF SYMBOLS 2 Organic EL display panel 3 Transparent substrate 4 Organic EL element 5 Sealing film 15 Plasma CVD apparatus 18 Induction coil 19 Gas supply part 51 2nd barrier layer 52 Stress relaxation layer 53 1st barrier layer 180 Winding part

Claims (12)

In the sealing film for covering and sealing the organic EL element mounted on the substrate,
It is composed of a plurality of layers including a barrier layer made of silicon nitride and a stress relaxation layer made of at least one of silicon oxynitride and silicon oxide disposed inside the barrier layer and laminated with the barrier layer. An organic EL element sealing film characterized by the above.   A barrier layer made of silicon nitride is provided on the inside of the stress relaxation layer and on which the stress relaxation layer is laminated. The barrier layer inside the stress relaxation layer directly covers the organic EL element. The organic EL device sealing film according to claim 1, wherein the organic EL device sealing film is configured.   3. The organic EL element sealing film according to claim 1, wherein a thickness of the barrier layer disposed outside the stress relaxation layer is set in a range of 500 to 8000 mm.   The layer thickness of the stress relaxation layer is set to 2 to 10 times the maximum thickness of the barrier layer disposed outside the stress relaxation layer. The sealing film of the organic EL element of any one of these.   The barrier layer and the stress relaxation layer are formed by an inductively coupled plasma CVD method in which a raw material gas is converted into a plasma by a magnetic field generated by a flat coil disposed opposite to the substrate to form a film on the substrate. The sealing film for an organic EL element according to claim 1, wherein the sealing film is an organic EL element sealing film.   The barrier layer is formed by using silane-based gas and nitrogen gas as the source gas, and the stress relaxation layer is formed by using silane-based gas, nitrogen gas and oxygen gas as the source gas. The sealing film of the organic EL element according to claim 5.   The organic EL display panel provided with the some organic EL element and the board | substrate with which these organic EL elements are mounted WHEREIN: The said organic EL element is by the sealing film of any one of Claims 1 thru | or 6. An organic EL display panel which is sealed. In an organic display panel manufacturing method for manufacturing an organic EL display panel by covering and sealing an organic EL element mounted on a substrate,
An element sealing step of laminating a first barrier layer made of silicon nitride as the first layer on the organic EL element, and a stress comprising at least one of silicon nitride oxide and silicon oxide as the second layer after the element sealing step A stress relaxation step of laminating a relaxation layer on the barrier layer, and a barrier step of laminating a second barrier layer made of silicon nitride on the stress relaxation layer as a third layer after the stress relaxation step. A manufacturing method of an organic EL display panel characterized by the above.   In the element sealing step, the stress relaxation step, and the barrier step, an inductively coupled plasma CVD apparatus that forms a film on the substrate by converting the raw material gas into a plasma by a magnetic field generated by a flat coil disposed opposite to the substrate is provided. 9. The method of manufacturing an organic EL display panel according to claim 8, wherein the first and second barrier layers and the stress relaxation layer are formed.   In the element sealing step, the stress relaxation step, and the barrier step, a plasma CVD apparatus in which the winding portion of the flat plate coil is formed in a substantially rectangular shape and the winding portion is arranged in parallel in a substantially same plane. 10. The method for producing an organic EL display panel according to claim 9, wherein the method is used.   The element sealing step and the barrier step use silane-based gas and nitrogen gas as the source gas, and the stress relaxation step uses silane-based gas, nitrogen gas and oxygen gas as the source gas. The manufacturing method of the organic electroluminescence display panel of Claim 9 or Claim 10.   The first and second barrier layers and the stress relaxation layer stacked in the element sealing step, the stress relaxation step, and the barrier step are formed in the plasma CVD apparatus under a pressure of 0.1 Pa or less. The manufacturing method of the organic electroluminescence display panel of any one of Claims 9 thru | or 11.

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