JP2017162547A - Organic el element and manufacturing method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a long-life organic EL element with flexibility.SOLUTION: An organic EL element 10 comprises: a first substrate 100 and a second substrate 110, both having flexibility, which are arranged to face each other; an organic light-emitting part 120, arranged between the first substrate 100 and the second substrate 110, which includes a first electrode 121, an organic layer 122 including a luminous layer, and a second electrode 123 that are sequentially laminated on the first substrate 100; and a filler 130 which is arranged between the first substrate 100 and the second substrate 110 so as to cover the organic light-emitting part 120. The filler 130 has a hollow buffer space 140 provided in a predetermined region in a plan view.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an organic EL (Electro-Luminescence) element and a manufacturing method thereof.

  An organic EL element is a light-emitting element that can be driven at a low voltage and a low current, and has advantages in that light emission luminance is large with respect to supplied power and light emission efficiency is good. For this reason, in recent years, various devices using organic EL elements, such as lighting devices and display devices using organic EL elements, have been developed.

  For example, Patent Document 1 discloses an organic EL display panel having a hermetically sealed structure. In the organic EL display panel described in Patent Document 1, a substrate provided with an organic EL light emitting element and a substrate provided with a color filter element are bonded together, and a resin-based filling is provided between these two substrates. The organic EL light emitting element is sealed with a material. Thereby, the organic EL light emitting element can be protected from moisture and the life can be extended.

JP 2008-235089 A

  However, when the conventional organic EL display panel is bent, the filler filled between the substrates may be destroyed. When the filler is destroyed, the sealing property of the light emitting layer is impaired, so that the deterioration of the light emitting layer is advanced due to the influence of moisture and the life of the organic EL display panel is shortened.

  In addition, the filler can be softened by adjusting the hardness of the filler so that the filler is not destroyed when the organic EL display panel is bent. However, the softened filler contains a lot of low-molecular materials. In this case, the low molecular weight material contained in the filler penetrates into the light emitting layer, promotes deterioration of the light emitting layer, and shortens the life of the organic EL display panel.

  Therefore, an object of the present invention is to provide a long-life organic EL element having flexibility and a method for manufacturing the same.

  In order to achieve the above object, an organic EL element according to one embodiment of the present invention includes a flexible first substrate and a second substrate that are arranged to face each other, and the first substrate and the second substrate. An organic light emitting unit provided, the first electrode stacked in order on the first substrate, an organic layer including a light emitting layer, an organic light emitting unit including a second electrode, and so as to cover the organic light emitting unit A filler provided between the first substrate and the second substrate is provided, and the filler is provided with a hollow buffer space in a predetermined region in plan view.

  According to the present invention, it is possible to provide a long-life organic EL element having flexibility and a manufacturing method thereof.

It is a schematic sectional drawing of the organic EL element which concerns on Embodiment 1 of this invention. It is a top view which shows an example of the arrangement pattern of the some buffer space which concerns on Embodiment 1 of this invention. It is a top view which shows another example of the arrangement pattern of the some buffer space which concerns on Embodiment 1 of this invention. It is a schematic sectional drawing which shows the formation process of the organic light emission part in the manufacturing method of the organic EL element which concerns on Embodiment 1 of this invention. It is a schematic sectional drawing which shows the application | coating process of the filler material in the manufacturing method of the organic EL element which concerns on Embodiment 1 of this invention. It is a schematic sectional drawing which shows the bonding process of the board | substrate in the manufacturing method of the organic EL element which concerns on Embodiment 1 of this invention. It is a general | schematic perspective view which shows an example of the application pattern of the filler material which concerns on Embodiment 1 of this invention. It is a general-view perspective view which shows another example of the application pattern of the filler material which concerns on Embodiment 1 of this invention. It is a schematic sectional drawing when the organic EL element which concerns on Embodiment 1 of this invention is bent. It is a schematic sectional drawing of the organic EL element which concerns on Embodiment 2 of this invention. It is a schematic sectional drawing when the organic EL element which concerns on Embodiment 2 of this invention is bent. It is a general | schematic perspective view which shows an example of the application pattern of the filler material which concerns on Embodiment 2 of this invention. It is a schematic sectional drawing of the organic EL element which concerns on Embodiment 3 of this invention. It is a schematic sectional drawing when the organic EL element which concerns on Embodiment 3 of this invention is bent. It is a schematic sectional drawing which shows the application | coating process of the filler material in the manufacturing method of the organic EL element which concerns on Embodiment 3 of this invention. It is a schematic sectional drawing which shows the bonding process of the board | substrate in the manufacturing method of the organic EL element which concerns on Embodiment 3 of this invention.

  Below, the organic EL element and its manufacturing method which concern on embodiment of this invention are demonstrated in detail using drawing. Note that each of the embodiments described below shows a preferred specific example of the present invention. Therefore, the numerical values, shapes, materials, components, component arrangements, connection forms, and the like shown in the following embodiments are merely examples, and are not intended to limit the present invention. Therefore, among the constituent elements in the following embodiments, constituent elements that are not described in the independent claims showing the highest concept of the present invention are described as optional constituent elements.

  Each figure is a mimetic diagram and is not necessarily illustrated strictly. Moreover, in each figure, the same code | symbol is attached | subjected about the same structural member.

(Embodiment 1)
[Organic EL device]
First, the organic EL element according to Embodiment 1 will be described with reference to FIG. FIG. 1 is a schematic cross-sectional view of an organic EL element 10 according to the present embodiment.

  As shown in FIG. 1, the organic EL element 10 includes a first substrate 100, a second substrate 110, an organic light emitting unit 120, and a filler 130. The filler 130 is provided with a plurality of buffer spaces 140.

  Although not shown, the organic EL element 10 is, for example, a planar light emitter having a substantially rectangular shape in plan view. Specifically, the planar view shapes of the first substrate 100, the second substrate 110, and the organic light emitting unit 120 are substantially rectangular. For example, the organic EL element 10 emits light in a substantially rectangular plane in the vertical direction of the drawing in FIG.

[substrate]
The first substrate 100 and the second substrate 110 are disposed to face each other. Specifically, the first substrate 100 and the second substrate 110 are arranged to face each other with a predetermined distance apart. For example, the distance between the first substrate 100 and the second substrate 110 is 10 μm to 100 μm, and is 30 μm as an example. The first substrate 100 and the second substrate 110 are bonded by a filler 130.

  The first substrate 100 and the second substrate 110 have flexibility. In other words, the first substrate 100 and the second substrate 110 are flexible and are bent when a force is applied from the outside.

  For example, the first substrate 100 and the second substrate 110 are thin glass or barrier films. Specifically, the first substrate 100 and the second substrate 110 are thin glass substrates such as soda glass and non-alkali glass. Alternatively, the first substrate 100 and the second substrate 110 may be a barrier film in which a moisture-proof film is formed on a resinous base material such as polycarbonate, acrylic resin, or polyethylene terephthalate. The moisture-proof film is, for example, a metal thin film.

  At least one of the first substrate 100 and the second substrate 110 has a light-transmitting property and transmits at least part of visible light. Thereby, the light emitted from the organic light emitting unit 120 can be extracted in one direction or both directions. As the first substrate 100 and the second substrate 110, for example, plate-shaped transparent substrates having a thickness of 0.03 mm to 1.2 mm, for example, 0.7 mm can be used.

  Note that the second substrate 110 may have light reflectivity, for example. Specifically, the second substrate 110 may be made of a metal material such as stainless steel or aluminum.

[Organic light emitting part]
The organic light emitting unit 120 is provided between the first substrate 100 and the second substrate 110 and emits light in a planar shape when a voltage is applied. The organic light emitting unit 120 includes a first electrode 121, an organic layer 122, and a second electrode 123. The first electrode 121, the organic layer 122, and the second electrode 123 are stacked on the first substrate 100 in this order.

  The first electrode 121 is an electrode provided on the light emitting surface side, and is provided on the first substrate 100, for example. The first electrode 121 is, for example, an anode, and has a higher potential than the second electrode 123 when the organic EL element 10 emits light.

  The first electrode 121 is made of a light-transmitting conductive material. For example, the first electrode 121 is made of a transparent conductive material that transmits at least part of visible light. The first electrode 121 is made of, for example, indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide doped with aluminum (AZO), or the like.

  The first electrode 121 may be a thin metal film such as silver or aluminum that can transmit light. Alternatively, Ag nanowires or Ag particles may be dispersed. Alternatively, as the first electrode 121, a conductive polymer such as PEDOT or polyaniline, a conductive polymer doped with any acceptor, or a conductive light-transmitting material such as a carbon nanotube can be used. .

  For example, the first electrode 121 is formed by forming a transparent conductive film on the first substrate 100 by vapor deposition, coating, sputtering, ion beam assist, or the like, and patterning the formed transparent conductive film. The For example, the film thickness of the first electrode 121 is 60 nm to 200 nm, and is 100 nm as an example.

  The organic layer 122 is provided between the first electrode 121 and the second electrode 123. The organic layer 122 includes a light emitting layer, and emits light in a planar shape when a voltage is applied between the first electrode 121 and the second electrode 123.

  Specifically, the organic layer 122 includes a hole injection layer, a hole transport layer, a light emitting layer (organic EL layer), an electron transport layer, and an electron injection layer. The organic layer 122 such as a light emitting layer is made of an organic material such as diamine, anthracene, or metal complex. Each layer constituting the organic layer 122 is formed by an evaporation method, a spin coating method, a casting method, an ion beam assist method, or the like. For example, the thickness of the organic layer 122 is 150 nm to 350 nm, and is 210 nm as an example.

  For example, when the emission color is white, the organic layer 122 is formed by doping the emission layer with dopant pigments of three colors of red, green, and blue. Alternatively, the organic layer 122 may have a stacked structure of a blue hole transporting light emitting layer, a green electron transporting light emitting layer, and a red electron transporting light emitting layer. The organic layer 122 may have a multi-unit structure in which red, green, and blue light-emitting units are stacked via an intermediate layer having light transmission and conductivity, and are electrically connected directly.

  The second electrode 123 is an electrode provided on the side opposite to the light emitting surface, and is provided on the organic layer 122, for example. The second electrode 123 is, for example, a cathode, and has a lower potential than the first electrode 121 when the organic EL element 10 emits light.

  The second electrode 123 is made of a conductive material having light reflectivity. The second electrode 123 reflects the light emitted from the organic layer 122 and emits it to the light emitting surface side. The second electrode 123 is made of, for example, a metal material such as aluminum, silver, or magnesium, or an alloy containing at least one of these. For example, the second electrode 123 is formed by depositing a conductive film on the organic layer 122 by vapor deposition, coating, sputtering, ion beam assist, GCIB (Gas Cluster Ion Beam) vapor deposition, or the like. For example, the thickness of the second electrode 123 is 20 nm to 200 nm, and is 100 nm as an example.

  Note that since the moisture permeability of the metal material is low, the second electrode 123 can protect the organic layer 122 from moisture. The second electrode 123 may be made of, for example, a conductive resin material.

  The second electrode 123 may be made of a light-transmitting conductive material. For example, the same material as the first electrode 121 can be used for the second electrode 123. In this case, if the 2nd board | substrate 110 is also comprised with the light transmissive material, the organic EL element 10 can be utilized for a window of a building or a vehicle as a double-sided light emitting type lighting device, for example.

  Although not shown, for example, an extraction electrode for supplying power to the first electrode 121 and the second electrode 123 is provided on the first substrate 100. Specifically, a first lead electrode electrically connected to the first electrode 121 and a second electrode 123 are electrically connected to the peripheral end portion of the first substrate 100 and outside the filler 130. Connected to the second extraction electrode. As the first extraction electrode and the second extraction electrode, for example, the same material as that of the first electrode 121 or the second electrode 123 can be used.

[Filler]
The filler 130 is provided between the first substrate 100 and the second substrate 110 so as to cover the organic light emitting unit 120. Specifically, the filler 130 is a resin material that is filled and cured between the first substrate 100 and the second substrate 110.

  For example, as the filler 130, a photocurable, thermosetting, or two-component curable adhesive resin such as an epoxy resin, an acrylic resin, or a silicone resin can be used. Alternatively, as the filler 130, a thermoplastic adhesive resin made of an acid-modified product such as polyethylene or polypropylene may be used.

  The filler 130 is formed by applying and curing a filler material made of a resin material. For example, depending on the viscosity and film thickness of the filler material, it can be filled by printing methods such as roll coating, spin coating, screen printing, spray coating, slit coating, squeegee coating, droplets with a dispenser, or drawing coating. A material material is applied. Details of the application of the filler material will be described later.

  Note that a sealing material may be provided so as to surround the filler 130. In other words, the filler 130 is a frame-shaped sealing material along the outer periphery of the first substrate 100, and is provided inside the sealing material that connects the first substrate 100 and the second substrate 110. For example, the sealing material is made of a material having a higher viscosity than that of the filler 130 and can be used as a dam material when the filler 130 is applied.

[Buffer space]
The buffer space 140 is a hollow space provided in a predetermined region in the plan view of the filler 130. As shown in FIG. 1, the buffer space 140 penetrates the filler 130 in the stacking direction.

  As shown in FIG. 1, the filler 130 is provided with a plurality of buffer spaces 140. The plurality of buffer spaces 140 are spaces that are closed independently of each other. Specifically, the buffer space 140 is a space surrounded by the filler 130, the second electrode 123, and the second substrate 110.

  The predetermined area where the buffer space 140 is provided is, for example, an area determined according to a predetermined arrangement pattern. In other words, the buffer space 140 is arranged according to a predetermined arrangement pattern. The arrangement pattern represents, for example, the arrangement of the buffer space 140 in a plan view.

  2A and 2B are plan views showing an example of an arrangement pattern of the plurality of buffer spaces 140 according to the present embodiment.

  The buffer space 140 is, for example, a region in a plan view in which a tensile stress greater than or equal to a predetermined stress is applied when the organic EL element 10 is bent in a predetermined shape when the organic EL element 10 is bent. Is provided. For example, the predetermined stress is a stress at which the filler 130 is destroyed (fracture stress) or a value of 80% or more of the fracture stress. In other words, the buffer space 140 is provided in a portion where the filler 130 is easily broken when the organic EL element 10 is bent.

  For example, as shown in FIG. 2A, the plurality of buffer spaces 140 have a substantially uniform size, and specifically, the planar view shape is a substantially circular shape. That is, the plurality of buffer spaces 140 are substantially cylindrical spaces having axes in the stacking direction. The maximum width (specifically, substantially circular diameter) of the buffer space 140 in plan view is, for example, not less than 10 μm and not more than 20 μm.

  The plurality of buffer spaces 140 are, for example, arranged in a matrix in the filler 130 at regular intervals. 2A shows an example in which 25 buffer spaces 140 are arranged in a matrix of 5 rows × 5 columns, the numbers in the row direction and the column direction are merely examples, and the present invention is not limited to this.

  The buffer space 140 may be a substantially spherical space instead of a substantially cylindrical shape. Specifically, the buffer space 140 may be a substantially spherical space having a diameter of 10 μm to 20 μm. For example, the buffer space 140 is a bubble confined in the filler 130 when the first substrate 100 and the second substrate 110 are bonded together.

  As shown in FIG. 2B, the plurality of buffer spaces 140 have a substantially uniform size, and specifically, the planar view shape is a substantially rectangular shape with rounded corners. The plurality of buffer spaces 140 are columnar spaces that are long in the first direction (the vertical direction on the paper surface). The first direction is a direction orthogonal to the second direction (the left-right direction on the paper surface), which is the bending direction of the organic EL element 10, in a plan view. That is, the first direction is the longitudinal direction of the buffer space 140, and the second direction is the short direction of the buffer space 140.

  The plurality of buffer spaces 140 are arranged in the short direction of the buffer space 140 in a plan view, for example. In other words, the plurality of buffer spaces 140 are arranged so as to be parallel to each other. In FIG. 2B, four buffer spaces 140 are arranged in parallel to each other, but the arrangement and the number thereof are not limited to this.

[Production method]
Then, the manufacturing method of the organic EL element 10 which concerns on this Embodiment is demonstrated using FIG. 3A-FIG. 4B.

  FIG. 3A to FIG. 3C are schematic cross-sectional views illustrating the formation process of the organic light emitting unit 120, the coating process of the filler material 131, and the bonding process of the substrate in the method for manufacturing the organic EL element 10 according to the present embodiment. . 4A and 4B are schematic perspective views showing an example of an application pattern of the filler material 131 according to the present embodiment.

  First, as shown in FIG. 3A, the first substrate 100 is prepared, and the organic light emitting unit 120 is formed on the first substrate 100. Specifically, the first electrode 121, the organic layer 122, and the second electrode 123 are stacked in this order on the first substrate 100. At this time, a first extraction electrode, a second extraction electrode, an insulating layer that insulates the first electrode 121 and the second electrode 123, and the like may be formed.

In addition, formation of each layer of the organic light emission part 120 is performed using the vapor deposition apparatus which has a vacuum chamber, for example. That is, the first electrode 121, the organic layer 122, and the second electrode 123 are formed under vacuum. The vacuum at this time is, for example, a pressure of 10 ⁻³ to 10 ⁻⁶ Pa or less.

  Next, as shown in FIG. 3B, a filler material 131 is applied onto the first substrate 100 using a dispenser 150. Specifically, the filler material 131 is applied on the second electrode 123 according to a predetermined application pattern. For example, the filler material 131 is applied with a predetermined interval d.

  For example, when the shape in which the organic EL element 10 is bent is determined in advance, when the organic EL element 10 is bent into the shape, a plane on which a tensile stress equal to or higher than the predetermined stress (for example, a breaking stress) described above is applied. The filler material 131 is applied to the region in view with a gap d. For example, when the organic EL element 10 is bent, the filler material 131 is applied to the portion where the filler 130 is easily broken at intervals d on both sides of the portion.

  For example, as shown in FIG. 4A, the filler material 131 is applied at regular intervals in the form of dots. The predetermined interval d is set based on the application amount (that is, the dripping amount) per point of the filler material 131 and the distance between the first substrate 100 and the second substrate 110 (that is, the inter-substrate distance). Is done. For example, the predetermined distance d is 0.5 mm to 6.0 mm, and is 2 mm as an example.

  Alternatively, as shown in FIG. 4B, the filler material 131 may be applied linearly at equal intervals. The predetermined interval d in this case is set based on the coating amount per line of the filler material 131 and the inter-substrate distance. For example, the predetermined distance d is 0.5 mm to 6.0 mm as in the case of FIG. 4A, and is 2 mm as an example.

  In addition, the application | coating process of the filler material 131 is performed under the same pressure as the bonding process of the board | substrate performed subsequently, for example. Alternatively, it may be performed under the same pressure as the step of forming the organic light emitting unit 120. For example, the size of the buffer space 140 can be adjusted by adjusting the pressure in the coating process and the bonding process.

  Although the filler material 131 is applied to the first substrate 100, it may be applied to the second substrate 110.

  Next, as shown in FIG. 3C, the first substrate 100 and the second substrate 110 are bonded together. Specifically, the first substrate 100 and the second substrate 110 are bonded together under a reduced pressure lower than the atmospheric pressure, and then released to the atmospheric pressure. When the filler material 131 connects the first substrate 100 and the second substrate 110, a buffer space 140 is formed between the adjacent filler materials 131.

  In this way, by bonding the first substrate 100 and the second substrate 110 so that the filler material 131 covers the organic light emitting unit 120, a hollow buffer space 140 is formed in a predetermined region in a plan view of the filler material 131. Form. Specifically, the buffer space 140 is formed around the central portion of the interval between the adjacent filler materials 131. In other words, the buffer space 140 is formed in a portion where the filler material 131 is not applied.

  At this time, the size of the buffer space 140 is adjusted by adjusting the pressure at the time of bonding and the load at the time of bonding.

  For example, the pressure in the buffer space 140 is a pressure reduced at the time of bonding. For this reason, when the buffer space 140 is opened to atmospheric pressure, it is pushed by the filler material 131 and becomes small. At this time, for example, by gradually increasing the pressure from the pressure at the time of bonding to the atmospheric pressure, the load applied between the substrates can be gradually increased. Thereby, the extent to which the buffer space 140 is crushed, that is, the size of the buffer space 140 can be adjusted.

  For example, the pressure when the first substrate 100 and the second substrate 110 are bonded together is a pressure of about 1 Pa or more. Note that the first substrate 100 and the second substrate 110 do not have to be bonded under reduced pressure, and may be bonded, for example, under atmospheric pressure. Specifically, the first substrate 100 and the second substrate 110 are fixed to a jig or the like, and for example, a roller-shaped pressing portion is pressed from one end portion of the upper surface of the second substrate 110 to the other end portion. Thus, the first substrate 100 and the second substrate 110 may be bonded together.

  After bonding the first substrate 100 and the second substrate 110, the filler material 131 is cured by light irradiation or the like, whereby the organic EL element 10 shown in FIG. 1 can be formed.

[Summary]
As described above, the organic EL element 10 according to the present embodiment includes the flexible first substrate 100 and the second substrate 110 that are disposed to face each other, and between the first substrate 100 and the second substrate 110. An organic light emitting unit 120 provided, the first electrode 121 sequentially stacked on the first substrate 100, the organic layer 122 including the light emitting layer, and the organic light emitting unit 120 including the second electrode 123, and the organic light emitting unit 120 is provided with a filler 130 provided between the first substrate 100 and the second substrate 110 so as to cover 120, and the filler 130 is provided with a hollow buffer space 140 in a predetermined region in plan view. ing.

  Here, FIG. 5 is a schematic cross-sectional view when the organic EL element 10 according to the present embodiment is bent.

  When the organic EL element 10 is bent, as shown in FIG. 5, since the buffer space 140 is provided, the stress applied to the filler 130 can be dispersed and the filler 130 can be made difficult to break. That is, it becomes easy to bend without the filler 130 being destroyed. Therefore, the organic EL element 10 can be flexible.

  Further, according to the present embodiment, since the buffer space 140 disperses the stress, it is not necessary to adjust the hardness of the filler 130. That is, since it is not necessary to use a filler that is softer than necessary, it is possible to prevent the filler 130 from destroying the light emitting layer of the organic light emitting unit 120.

  In addition, for example, conventionally, when forming a hermetic sealing structure, a space may be formed at the end portion of the filler material without appropriately spreading in the sealing space. That is, a space is provided in the end portion of the filler in the related art, whereas in the present embodiment, the buffer space 140 is formed in the filler 130. For example, as shown in FIG. 1, the buffer space 140 is surrounded by the filler 130, and only the stacking direction is covered by the second substrate 110 and the second electrode 123.

  As described above, in the present embodiment, by providing the buffer space 140 in a predetermined region, for example, the organic EL element 10 can be bent in the region. In other words, the buffer space 140 can be formed in the region to be bent.

  For example, the buffer space 140 may be provided according to a predetermined arrangement pattern.

  Thereby, for example, the plurality of buffer spaces 140 can be regularly arranged, and the stress when the organic EL element 10 is bent can be more appropriately dispersed. That is, the flexibility of the organic EL element 10 can be further improved.

  Further, for example, the predetermined region is a region where a tensile stress equal to or greater than a predetermined stress is applied when the organic EL element 10 is bent into the shape when the shape in which the organic EL element 10 is bent is predetermined. is there.

  Thereby, a tensile stress is applied when the organic EL element 10 is bent into a predetermined shape, and the buffer space 140 can be provided in a portion of the filler 130 that is easily broken. Therefore, the stress can be dispersed by the buffer space 140 and the filler 130 can be made difficult to break.

  For example, the organic EL element 10 may be manufactured by being predetermined to be attached to a predetermined curved surface. Specifically, since the shape in which the organic EL element 10 is bent is determined in advance, it is conceivable to manufacture an organic EL element having the shape, that is, an organic EL element having a curved surface.

  However, an organic EL element having a curved surface has a problem that it is difficult to form a light emitting layer having a uniform thickness, for example. Moreover, it is preferable to manufacture an organic EL element having a flat surface from the viewpoint of ease of transportation and to bend it at the time of attachment.

  On the other hand, since the organic EL element 10 according to the present embodiment has a flat surface, it can be easily manufactured and transported. In addition, since the buffer space 140 is arranged according to the shape in which the organic EL element 10 is bent, it can be made difficult to be destroyed when bent.

  Further, for example, the buffer space 140 may be a columnar space that is long in a first direction orthogonal to the second direction, which is the bending direction of the organic EL element 10, in a plan view.

  Thereby, since the buffer space 140 is provided so as to cross the bending direction of the organic EL element 10, the tensile stress can be appropriately dispersed by the buffer space 140.

  For example, the maximum width in the second direction of the buffer space 140 may be 10 μm or more and 20 μm or less. Alternatively, for example, the buffer space 140 may be a substantially spherical space having a diameter of 10 μm to 20 μm.

  Here, as the buffer space 140 is increased or the number of the buffer spaces 140 is increased, the sealing property of the organic light emitting unit 120 may be impaired and the deterioration of the light emitting layer may progress. Therefore, it is preferable that the buffer space 140 is small and small. Therefore, by setting the maximum width of the buffer space 140 to 10 μm or more and 20 μm or less, it is possible to disperse the tensile stress and to suppress the sealing performance of the organic light emitting unit 120 from being impaired.

  In addition, for example, the method of manufacturing the organic EL element 10 according to the present embodiment includes an organic EL element including the organic light emitting unit 120 including the first electrode 121, the organic layer 122 including the light emitting layer, and the second electrode 123. 10, a stacking process in which the first electrode 121, the organic layer 122, and the second electrode 123 are stacked in this order on the first substrate 100, and the first substrate 100 and the second substrate 110. And applying the first substrate 100 and the second substrate 110 so that the filler material 131 covers the organic light emitting unit 120 at a predetermined interval in a plan view. And a bonding step of forming a hollow buffer space 140 in the filler material 131.

  Thereby, as described above, the organic EL element 10 having flexibility and a long lifetime can be provided.

  Specifically, in the present embodiment, the buffer space 140 is formed by applying the filler material 131 at a predetermined interval. That is, the buffer material 140 is formed when the substrates are bonded to each other depending on the application position and the application amount of the filler material 131 instead of including bubbles in the filler material 131 in advance. Therefore, the size of the buffer space 140 can be easily adjusted, and the tensile stress can be effectively dispersed.

  Further, for example, in the application process, the filler material 131 may be applied according to a predetermined application pattern.

  Thereby, the magnitude | size of the buffer space 140 can be adjusted by adjusting arrangement | positioning and the space | interval of the filler material 131. FIG. In other words, by adjusting the application position of the filler material 131, the buffer space 140 having a desired size can be formed at a desired position. Therefore, for example, the size of the buffer space 140 can be easily adjusted according to the required degree of flexibility.

  Further, for example, in a coating process, when a shape in which the organic EL element 10 is bent is determined in advance, when the organic EL element 10 is bent into the shape, a tensile stress greater than a predetermined stress is applied in a plan view. The filler material 131 is applied to the region at the above interval.

  Thereby, a tensile stress is applied when the organic EL element 10 is bent into a predetermined shape, and the buffer space 140 can be provided in a portion of the filler 130 that is easily broken. Therefore, it is possible to provide the organic EL element 10 having flexibility and long life.

(Embodiment 2)
Next, the organic EL element according to Embodiment 2 will be described with reference to the drawings.

  FIG. 6 is a schematic cross-sectional view of the organic EL element 20 according to this embodiment.

  In the first embodiment, the plurality of buffer spaces 140 are provided at equal intervals, whereas in the present embodiment, the maximum tensile stress is applied when the organic EL element 20 is bent into a predetermined shape. More buffer spaces 240 are provided in the first region including the portion than in the second region different from the first region. That is, many buffer spaces 240 are provided in the first region where the filler 230 is most easily destroyed when the organic EL element 20 is bent.

  For example, when the bent shape of the organic EL element 20 is determined in advance, the first region where the tensile stress is most applied and is most easily destroyed when the organic EL element 20 is bent is determined in advance. The arrangement pattern is determined so that many buffer spaces 240 are arranged in the first region.

  FIG. 7 is a schematic cross-sectional view when the organic EL element 20 according to the present embodiment is bent.

  For example, consider a case where the planar organic EL element 20 is attached to the side surface of a predetermined cylindrical body. Specifically, the organic EL element 20 is bent so as to protrude toward the first substrate 100 side which is a light emitting surface.

  In this case, the tensile stress is larger as it is closer to the central portion in the bending direction of the organic EL element 20 and is smaller as it is closer to the end of the organic EL element 20. The maximum tensile stress is applied at the central portion of the organic EL element 20 in the bending direction.

  Specifically, as shown in FIG. 7, the tensile stress is large in the central region 260 in the bending direction of the organic EL element 20, and the tensile stress is small in the end region 261. The central region 260 is an example of a first region, and is a region where a tensile stress greater than a predetermined stress is applied when the organic EL element 20 is bent. The central region 260 includes a portion where the maximum tensile stress is applied, specifically, a central portion in the bending direction of the organic EL element 20. The end region 261 is an example of a second region, and is a region where a tensile stress smaller than a predetermined stress is applied when the organic EL element 20 is bent.

  In the present embodiment, as shown in FIG. 6, more buffer space 240 is provided in the central region 260 than in the end region 261. Thereby, the big tensile stress concerning the center area | region 260 can be disperse | distributed effectively.

  Moreover, in the manufacturing method of the organic EL element 20 according to the present embodiment, for example, in the coating process, when the shape in which the organic EL element 20 is bent is predetermined, the organic EL element 20 is bent into the shape. Sometimes, a smaller amount of the filler material 231 is applied to the first region in plan view where the maximum tensile stress is applied than in the second region different from the first region.

  FIG. 8 is a schematic perspective view showing an example of an application pattern of the filler material 231 according to the present embodiment.

  As shown in FIG. 8, in the present embodiment, a filler material 231 is applied to the first substrate 100 in a linear shape. Specifically, the filler material 231 is applied on the second electrode 123 stacked on the first substrate 100.

  At this time, for example, the filler material 231 is applied so that the longitudinal direction is perpendicular to the bending direction of the organic EL element 20. Furthermore, the application amount of the filler material 231 applied to the central region 260 is made smaller than the application amount of the filler material 231 applied to the end region 261. In addition, the application amount at this time is an application amount per unit area.

  For example, as shown in FIG. 8, the filler material 231 is linearly applied to the central region 260 at the interval d1. A filler material 231 is applied to the end region 261 at intervals d1 and d2 (<d1). By applying the filler material 231 at the interval d1, the buffer space 240 can be formed as in the first embodiment. On the other hand, by applying the filler material 231 at the interval d2, the adjacent filler material 231 adheres when the substrates are bonded together, and the buffer space 240 is not formed.

  As a result, as shown in FIG. 6, four buffer spaces 240 are formed in the central region 260, and one buffer space 240 is formed in each of the end regions 261. That is, more buffer spaces 240 can be formed in the central region 260 than in the end region 261. Thereby, when the organic EL element 20 is bent into a predetermined shape, the tensile stress can be effectively dispersed.

(Embodiment 3)
Next, the organic EL element according to Embodiment 3 will be described with reference to the drawings.

  FIG. 9 is a schematic cross-sectional view of the organic EL element 30 according to the present embodiment.

  In the organic EL element 30 according to the present embodiment, the buffer space 340 is provided inside the filler 330 as shown in FIG. Specifically, all the directions of the buffer space 340 are surrounded by the filler 330. In other words, the buffer space 340 is a closed space surrounded only by the filler 330.

  FIG. 10 is a schematic cross-sectional view when the organic EL element 30 according to the present embodiment is bent.

  When the organic EL element 30 is bent, as shown in FIG. 10, since the buffer space 340 is provided inside the filler 330, the stress applied to the filler 330 is dispersed and the filler 330 is not easily destroyed. be able to. That is, since the buffer space 340 disperses the stress, the filler 330 is not broken and is easily bent. Therefore, the organic EL element 30 can be flexible.

  The organic light emitting unit 120 is completely covered with the filler 330. In other words, the organic light emitting unit 120 is not exposed to the buffer space 340. For this reason, compared with Embodiment 1 and 2, the sealing performance of the organic light emission part 120 can be improved more.

  Next, a method for manufacturing the organic EL element 30 according to the present embodiment will be described with reference to FIGS. 11A and 11B. FIG. 11A and FIG. 11B are schematic cross-sectional views illustrating a coating process of filler materials 331 and 332 and a substrate bonding process in the method of manufacturing organic EL element 30 according to the present embodiment.

  In the present embodiment, first, the formation process of the organic light emitting unit 120 shown in FIG. 3A is performed. Next, as shown in FIG. 11A, filler materials 331 and 332 are applied to both the first substrate 100 and the second substrate 110 using the dispenser 150, respectively.

  Specifically, a filler material 331 is applied on the first substrate 100. For example, the filler material 331 is applied on the second electrode 123 according to a predetermined application pattern. The filler material 331 is applied with a predetermined interval d.

  Further, a filler material 332 is applied on the second substrate 110. The filler material 331 and the filler material 332 are the same resin material. The application pattern of the filler material 331 and the application pattern of the filler material 332 are the same. Therefore, when the first substrate 100 and the second substrate 110 face each other for bonding, the filler material 331 and the filler material 332 face each other. The filler materials 331 and 332 are applied in a dotted or linear manner, for example, as shown in FIGS. 4A and 4B.

  Next, as shown in FIG. 11B, the first substrate 100 and the second substrate 110 are bonded together. The filler material 331 and the filler material 332 are in contact with each other, and each flow along the surface of the second electrode 123 or the second substrate 110. The filler material 331 covers the surface of the second electrode 123, and the filler material 332 covers the surface of the second substrate 110, so that the second electrode 123 and the second substrate 110 are not exposed to the buffer space 340.

  After the bonding of the first substrate 100 and the second substrate 110 is completed, the buffer material 331 and 332 are cured by light irradiation or the like to form the buffer space 340 in the filler 330.

(Other)
As mentioned above, although the organic EL element concerning this invention and its manufacturing method were demonstrated based on the said embodiment, this invention is not limited to said embodiment.

  For example, in the above-described embodiment, an example in which the plurality of buffer spaces 140 are arranged in an orderly manner has been described. However, the buffer spaces 140 may be randomly arranged.

  For example, in the above embodiment, an example in which a plurality of buffer spaces 140 are provided has been described, but only one buffer space 140 may be provided. The planar view shape of only one buffer space 140 may be a substantially circular shape or a substantially rectangular shape, or may be provided in a ring shape or a lattice shape.

  Further, for example, in the above-described embodiment, an example in which both the second electrode 123 and the second substrate 110 are exposed in the buffer space 140 has been described, but either the second electrode 123 or the second substrate 110 is shown. Only may be exposed.

  For example, in the above embodiment, the filler 130 is provided on the second substrate 110, but a protective film may be provided on the second substrate 110. For example, the protective film is a film having a low moisture permeability such as a silicon nitride film. The protective film includes a vapor deposition method, a coating method, a sputtering method, an ion beam assist method, a GCIB (Gas Cluster Ion Beam) vapor deposition method and a CVD method (with relatively low temperature and low damage conditions such as ALD (Atomic Layer Deposition) or plasma CVD). Formed by.

  Further, for example, in the above embodiment, an example in which the first electrode 121 is an anode and the second electrode 123 is a cathode is shown, but the reverse may be possible. That is, the first electrode 121 may be a cathode and the second electrode 123 may be an anode.

  Further, for example, in the above-described embodiment, the example in which the planar view shape of the organic EL element 10 is rectangular has been described, but the present invention is not limited thereto. For example, the planar view shape of the organic EL element 10 may be a closed shape drawn by a straight line or a curve, such as a polygon, a circle, or an ellipse.

  Further, for example, in the above-described embodiment, the bottom emission type organic EL element 10 that emits light toward the first substrate 100 is shown, but a top emission type that emits light toward the second substrate 110 may be used. In this case, for example, the first electrode 121 is made of a light reflective material, and the second electrode 123 and the second substrate 110 are made of a light transmissive material.

  In addition, the embodiment can be realized by arbitrarily combining the components and functions in each embodiment without departing from the scope of the present invention, or a form obtained by subjecting each embodiment to various modifications conceived by those skilled in the art. Forms are also included in the present invention.

10, 20, 30 Organic EL element 100 First substrate 110 Second substrate 120 Organic light emitting unit 121 First electrode 122 Organic layer 123 Second electrodes 130, 230, 330 Fillers 131, 231, 331, 332 Filler material 140, 240, 340 Buffer space 260 Central region (first region)
261 end region (second region)

Claims (13)

A flexible first substrate and a second substrate disposed opposite to each other;
An organic light emitting unit provided between the first substrate and the second substrate, comprising a first electrode, an organic layer including a light emitting layer, and a second electrode sequentially stacked on the first substrate. An organic light emitting part;
A filler provided between the first substrate and the second substrate so as to cover the organic light emitting unit;
An organic EL element in which the filler is provided with a hollow buffer space in a predetermined region in plan view. The organic EL element according to claim 1, wherein the buffer space is provided according to a predetermined arrangement pattern. The predetermined region is a region to which a tensile stress greater than or equal to a predetermined stress is applied when the organic EL element is bent into the shape when a shape in which the organic EL element is bent is predetermined. 3. The organic EL device according to 1 or 2. The filler is provided with a plurality of buffer spaces,
The predetermined area is:
When a shape in which the organic EL element is bent is predetermined, a first region including a portion where the maximum tensile stress is applied when the organic EL element is bent into the shape;
A second region different from the first region,
The organic EL element according to any one of claims 1 to 3, wherein the first region is provided with more buffer spaces than the second region. The organic EL element according to claim 1, wherein the buffer space is a columnar space that is long in a first direction orthogonal to the second direction, which is a bending direction of the organic EL element, in a plan view. The organic EL element according to claim 5, wherein a maximum width of the buffer space in the second direction is not less than 10 μm and not more than 20 μm. The organic EL device according to claim 1, wherein the buffer space is a substantially spherical space having a diameter of 10 μm to 20 μm. The organic EL element according to claim 1, wherein the buffer space is a space that penetrates the filler in the stacking direction. The organic EL element according to claim 1, wherein the buffer space is provided inside the filler. A method for manufacturing an organic EL device comprising an organic light emitting unit including a first electrode, an organic layer including a light emitting layer, and a second electrode,
A laminating step of laminating the first electrode, the organic layer, and the second electrode in this order on the first substrate;
An application step of applying a filler material to at least one of the first substrate and the second substrate at a predetermined interval in a plan view;
A bonding step of forming a hollow buffer space in the filler material by bonding the first substrate and the second substrate so that the filler material covers the organic light-emitting portion; Manufacturing method. The method for manufacturing an organic EL element according to claim 10, wherein, in the application step, the filler material is applied according to a predetermined application pattern. In the coating step, when a shape in which the organic EL element is bent is determined in advance, when the organic EL element is bent into the shape, a region in plan view where a tensile stress equal to or higher than a predetermined stress is applied, The method for manufacturing an organic EL element according to claim 10, wherein the filler material is applied with the space therebetween. In the application step, when a shape in which the organic EL element is bent is determined in advance, when the organic EL element is bent into the shape, The method for manufacturing an organic EL element according to claim 10, wherein a smaller amount of the filler material is applied than in a second region different from the first region.

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