Device structure and method of manufacturing the same

Abstract

A device structure comprising a substrate and a multilayer having a device portion formed on the substrate, and a sealing layer encapsulating the device portion, wherein the sealing layer has a structure in which an organic sealing layer and an inorganic sealing layer are stacked in this order with respect to the device portion, wherein the inorganic sealing layer comprises silicon nitride and the organic sealing layer comprises a thermoplastic elastomer, and furthermore, the residual film rate of the organic sealing layer in a dissolution test for dibutyl ether is 90% or more. The sealing layer comprises a first sealing layer formed on the device portion, and two or more second sealing layers and two or more third sealing layers formed on the first sealing layer, and has a structure in which the second sealing layer and the third sealing layer are alternately stacked, wherein the second sealing layer is the inorganic sealing layer and the third sealing layer is the organic sealing layer.

Description

Technology Field

[0001] The present invention relates to a device structure and a method for manufacturing the same. Background Technology

[0002] In devices such as organic electroluminescence devices and flexible touch sensors, it is sometimes required to install components that suppress the intrusion of moisture into the device. For example, an organic electroluminescence device may include a substrate such as a glass plate and a device part comprising an electrode layer and a light-emitting layer formed on the substrate. Some materials included in the device part may deteriorate due to the intrusion of moisture. Accordingly, in order to suppress the intrusion of moisture into the device part, a sealing layer that encloses the device part may be formed.

[0003] In many devices, the encapsulation layer comprises an organic encapsulation layer formed of an organic material and an inorganic encapsulation layer formed of an inorganic material (Patent Document 1). Conventionally, the organic encapsulation layer was generally formed under atmospheric pressure. In addition, the inorganic encapsulation layer was often formed under a vacuum environment by methods such as the CVD (Chemical Vapor Deposition) method.

[0004] However, the process under a vacuum environment as described in Patent Document 1 was a cause of high costs because the device for forming the inorganic encapsulation layer became large and complex. In particular, in processes such as the plasma CVD method using plasma, particles such as plasma dust were generated, and these particles could cause degradation of the device part.

[0005] Against this backdrop, there is a demand for the development of a technology capable of forming an inorganic encapsulation layer under atmospheric pressure. In response to this demand, a method has recently been developed to form an inorganic encapsulation layer containing silicon nitride under atmospheric pressure using a polysilazane compound (Patent Document 2 and Non-Patent Document 1). Prior art literature

[0006] Japanese Published Patent Application No. 2018-147812 Japanese Published Patent Application No. 2015-202620

[0007] Lina Sun, Kaho Uemura, Tatsuhiro Takahashi, Tsukasa Yoshida, Yoshiyuki Suzuri, 「Interfacial Engineering in Solution Processing of Silicon-Based Hybrid Multilayer for High Performance Thin Film Encapsulation」, ACS Appl. Mater. Interfaces, 11, 43425-43432(2019) The problem to be solved

[0008] Encapsulation layers comprising an inorganic encapsulation layer and an organic encapsulation layer containing silicon nitride require improved encapsulation performance under high temperature and high humidity environments. The present invention, made in consideration of the above circumstances, aims to provide a device structure having an encapsulation layer comprising silicon nitride and having good encapsulation performance under high temperature and high humidity environments, and a manufacturing method that can easily form said device structure. means of solving the problem

[0009] The inventors obtained the following findings as a result of careful consideration to solve the above problem. In forming an inorganic encapsulation layer using a liquid composition containing a polysilazane compound, dibutyl ether is one of the solvents suitably used because it has little effect on the polysilazane compound. However, it was found that dibutyl ether is prone to causing damage to an organic encapsulation layer containing a thermoplastic elastomer. Regarding this problem, the inventors found that the resistance of the organic encapsulation layer to dibutyl ether can be improved by irradiating the organic encapsulation layer with vacuum ultraviolet light. The present invention is an invention based on these findings and includes the following.

[0010] [1] A device structure comprising a substrate and a multilayer having a device portion formed on the substrate, and a sealing layer that encapsulates the device portion, wherein the sealing layer has a structure in which an organic sealing layer and an inorganic sealing layer are stacked in this order with respect to the device portion, wherein the inorganic sealing layer comprises silicon nitride and the organic sealing layer comprises a thermoplastic elastomer, and furthermore, the residual film rate of the organic sealing layer in a dissolution test for dibutyl ether is 90% or more.

[0011] [2] The above-described device structure, wherein the above-described encapsulation layer comprises a first encapsulation layer formed on the device portion, and two or more second encapsulation layers and two or more third encapsulation layers formed on the first encapsulation layer, and the second encapsulation layer and the third encapsulation layer are alternately stacked, and the second encapsulation layer is the inorganic encapsulation layer and the third encapsulation layer is the organic encapsulation layer.

[0012] [3] The device structure described in [1] or [2], wherein the first encapsulation layer is the organic encapsulation layer or a silicone encapsulation layer containing silicone.

[0013] [4] A device structure described in any one of [1] to [3], wherein the thermoplastic elastomer is one or more selected from the group consisting of hydrogenated aromatic vinyl compound-conjugated diene block copolymers and modified products of hydrogenated aromatic vinyl compound-conjugated diene block copolymers by silicon atom-containing polar groups.

[0014] [5] The above hydrogenated aromatic vinyl compound-conjugated diene block copolymer has a structure in which both the non-aromatic carbon-carbon unsaturated bond and the aromatic carbon-carbon unsaturated bond are hydrogenated, as described in [4] the device structure.

[0015] [6] A device structure described in any one of claims [1] to [5], wherein the above organic encapsulation layer comprises one or more types selected from the group consisting of a moisture adsorbent and a UV absorber.

[0016] [7] A device structure described in any one of [1] to [6], wherein the thickness of each constituent layer included in the above-mentioned encapsulation layer is 300 nm or less.

[0017] [8] The above device structure, which is an organic electroluminescent device, is described in any one of [1] to [7].

[0018] [9] A method for manufacturing a device structure comprising a process (a) for preparing a multilayer having a substrate and a device portion formed on the substrate, and a process (b) for forming a sealing layer that encapsulates the device portion, wherein the process (b) for forming the sealing layer comprises a process (b1) for forming an organic sealing layer and a process (b2) for forming an inorganic sealing layer after the process (b1), wherein the process (b1) comprises a process (b1-1) for forming an organic intermediate layer including a thermoplastic elastomer and a process (b1-2) for obtaining the organic sealing layer by irradiating the organic intermediate layer with vacuum ultraviolet light, and wherein the process (b2) comprises a process (b2-1) for forming an intermediate layer using a liquid composition including a polysilazane compound and a solvent, and a process (b2-2) for obtaining an inorganic sealing layer including silicon nitride by irradiating the intermediate layer with ultraviolet light.

[0019]

[10] A method for manufacturing a device structure as described in [9], wherein the liquid phase composition of process (b) comprises dibutyl ether as the solvent.

[0020]

[11] A method for manufacturing a device structure as described in [9] or

[10] , wherein the above process (b1-2) comprises a process (b1-2-1) of irradiating vacuum ultraviolet light under an inert gas atmosphere on the organic intermediate layer, and a process (b1-2-2) of irradiating vacuum ultraviolet light under a mixed atmosphere of inert gas and oxygen on the organic intermediate layer after the above process (b1-2-1).

[0021]

[12] A method for manufacturing a device structure described in any one of [9] to

[11] , wherein the above process (b) comprises a process (b3) for forming a first encapsulation layer, a process (b4) for forming a second encapsulation layer as an inorganic encapsulation layer formed on the first encapsulation layer, and a process (b5) for forming a third encapsulation layer as an organic encapsulation layer formed on the second encapsulation layer, wherein the process (b4) and the process (b5) are performed alternately at least twice, and the process (b4) is the process (b2) and the process (b5) is the process (b1).

[0022]

[13] A method for manufacturing a device structure described in

[12] , wherein the above process (b3) is the above process (b1) and is a process for forming the first encapsulation layer as the organic encapsulation layer. Effects of the invention

[0023] According to the present invention, a device structure having a sealing layer comprising silicon nitride and having good sealing performance under high temperature and high humidity environments, and a manufacturing method for easily forming the device structure can be provided. Brief explanation of the drawing

[0024] FIG. 1 is a cross-sectional view schematically showing a device structure according to one embodiment of the present invention. FIG. 2 is a cross-sectional view schematically showing a multilayer prepared in process (a) of a method for manufacturing a device structure according to one embodiment of the present invention. FIG. 3 is a cross-sectional view schematically showing a first encapsulation layer formed on a multilayer structure to encapsulate a device portion in process (b) of a method for manufacturing a device structure according to one embodiment of the present invention. FIG. 4 is a cross-sectional view schematically showing a second encapsulation layer as an inorganic encapsulation layer formed on a multilayer in process (b) of a method for manufacturing a device structure according to one embodiment of the present invention. FIG. 5 is a cross-sectional view schematically showing a third encapsulation layer as an organic encapsulation layer formed on a multilayer in process (b) of a method for manufacturing a device structure according to one embodiment of the present invention. FIG. 6 is a cross-sectional view schematically showing that, in process (b) of a method for manufacturing a device structure according to one embodiment of the present invention, a second encapsulation layer as an inorganic encapsulation layer and a third encapsulation layer as an organic encapsulation layer are alternately formed on a multilayer. Figure 7 is a diagram showing a table representing the results of microscopic observation of the examples and comparative examples. Figure 8 is a graph showing the change in shrinkage of the examples and comparative examples. Specific details for implementing the invention

[0025] The present invention will be described in detail below by presenting embodiments and examples. However, the present invention is not limited to the embodiments and examples shown below, and may be implemented with arbitrary modifications within the scope of the claims and equivalents thereof without departing from the scope of the present invention.

[0026] In the following description, unless otherwise noted, “(meth)acrylic” is a term including “acrylic,” “methacrylic,” and combinations thereof. For example, “(meth)acrylate alkyl ester” includes alkyl acrylate esters, alkyl methacrylate esters, or mixtures thereof.

[0027] In the following description, the term "solvent" refers, for the sake of convenience of explanation, to include not only the medium in the solution but also the dispersion medium that disperses solids therein.

[0028] [I. Device Structure]

[0029] A device structure according to one embodiment of the present invention comprises a multilayer having a substrate and a device portion formed on the substrate, and a device structure including a sealing layer that encapsulates the device portion, wherein the sealing layer has a structure in which an organic sealing layer and an inorganic sealing layer are stacked in this order with respect to the device portion, wherein the inorganic sealing layer comprises silicon nitride and the organic sealing layer comprises a thermoplastic elastomer, and furthermore, in a dissolution test for dibutyl ether, the residual film rate of the organic sealing layer is 90% or more.

[0030] FIG. 1 is a cross-sectional view schematically illustrating a device structure according to an embodiment of the present invention. The device structure (10) comprises a multilayer (100) having a substrate (110) and an element part (120) formed on the substrate (110), and an encapsulation layer (200) encapsulating the element part (120). The encapsulation layer (200) has a structure in which an organic encapsulation layer (210) and an inorganic encapsulation layer (220) are stacked in this order with respect to the element part (120). The inorganic encapsulation layer (220) includes silicon nitride. The organic encapsulation layer (210) includes a thermoplastic elastomer, and furthermore, the residual film rate of the organic encapsulation layer (210) in a dissolution test for dibutyl ether is 90% or more.

[0031] In the device structure (10) shown in FIG. 1, the encapsulation layer (200) comprises a first encapsulation layer (201) formed on the device part (120), a third encapsulation layer (202) and a third encapsulation layer (203) formed on the first encapsulation layer (201), and has a structure in which the second encapsulation layer (202) and the third encapsulation layer (203) are alternately stacked, and the second encapsulation layer (202) is an inorganic encapsulation layer (220) and the third encapsulation layer (203) is an organic encapsulation layer (210). Additionally, the first encapsulation layer (201) is a silicon encapsulation layer (230).

[0032] Here, dibutyl ether is one of the preferred solvents for polysilazane compounds in the method of forming an inorganic encapsulation layer using polysilazane compounds, because it has low reactivity toward the polysilazane compounds. On the other hand, dibutyl ether may dissolve thermoplastic elastomers. Therefore, when forming an encapsulation layer by laminating an inorganic encapsulation layer onto an organic encapsulation layer, if a liquid composition containing polysilazane compounds and dibutyl ether is coated onto the organic encapsulation layer, the organic encapsulation layer may degrade due to dibutyl ether, and sufficient encapsulation performance may not be obtained for the entire encapsulation layer. In contrast, the device structure according to the present embodiment has a high residual film rate of the organic encapsulation layer in the dissolution test with dibutyl ether, so the organic encapsulation layer has high resistance to dibutyl ether. Therefore, even when the aforementioned liquid composition is coated onto the organic encapsulation layer, the degradation of the organic encapsulation layer due to dibutyl ether can be suppressed. Therefore, since the organic and inorganic bag layers can be laminated in good condition, the bagging performance under high temperature and high humidity environments can be improved.

[0033] [1. Multi-story building]

[0034] The multilayer (100) includes a substrate and an element formed on the substrate.

[0035] As for the substrate (110), a suitable material capable of forming a device structure may be adopted. Examples of the substrate (110) include a glass plate, a resin plate, and a resin film. The substrate may have only one layer or may have multiple layers. For example, a substrate (110) comprising a resin film and a barrier layer formed on its surface may be used.

[0036] As for the device part (120), a suitable one capable of constituting a device structure may be adopted. Typically, the device part (120) includes one or more conductive layers. The layer indicated by the term "conductor layer" includes various layers that exhibit their function through the movement of electrons within the layer. Accordingly, the term "conductor layer" may include not only a layer with high conductivity, such as a metal, but also an organic thin layer, such as a light-emitting layer, which has relatively low conductivity. In the device structure according to the present embodiment, a sealing layer is typically formed to suppress deterioration of the conductive layer due to moisture.

[0037] Examples of a conductive layer include, for instance, an electrode layer, a light-emitting layer, and a combination thereof that constitute an organic electroluminescent element; and patterned wiring that constitutes a touch panel. The conductive layer may be formed to occupy a large area on the substrate (110). Additionally, the conductive layer may be formed to have any surface shape, such as a strip shape, a fine line shape, a rectangular shape, or a dot shape, similar to wiring and other structures on the substrate (110).

[0038] The number of conductive layers provided by the element part (120) may be 1 or 2 or more. When the element part (120) has 2 or more layers, the layers may be arranged without overlapping, or some or all of the layers may be overlapping.

[0039] The element part (120) may include a component other than a conductive layer on the interior or surface of the element part (120). Examples of such a component include a component that maintains the mechanical structure of the element part (120). Specific examples of this component include a component of a display element such as a liquid crystal cell or an organic electroluminescence element.

[0040] In FIG. 1, an organic electroluminescence device part is described as an example having a first electrode layer (121), a light-emitting layer (122), and a second electrode layer (123) arranged in this order in the thickness direction as a device part (120). The first electrode layer (121), the light-emitting layer (122), and the second electrode layer (123) are all conductive layers, and typically, the light-emitting layer (122) can generate light by applying voltage from the first electrode layer (121) and the second electrode layer (123). Examples of materials for the light-emitting layer (122) include poly(paraphenylenevinylene)-based, polyfluorene-based, and polyvinylcarbazole-based materials. Additionally, the light-emitting layer (122) may have a laminate of layers with multiple light-emitting colors, or a mixed layer in which a layer of one pigment is doped with another pigment. Additionally, the device part (120) may be provided with functional layers (not shown), such as a hole injection layer, a hole transport layer, an electron injection layer, an electron transport layer, an equipotential surface forming layer, and a charge generation layer.

[0041] The multilayer (100) can be manufactured by a manufacturing method including, for example, forming a component part (120) on a substrate (110). As a method for forming the component part (120), for example, a method of forming a conductive layer on the substrate (110) by a method such as sputtering or deposition may be cited.

[0042] [2. Bag layer]

[0043] The encapsulation layer (200) has a structure in which an organic encapsulation layer (210) and an inorganic encapsulation layer (220) are stacked in this order with respect to the element part (120). The encapsulation layer (200) is a layer formed to encapsulate at least a portion of the element part (120), and preferably, it is formed to encapsulate all or most of the element part (120). In this embodiment, an example is described in which the encapsulation part is formed to encapsulate the entire portion that is not in contact with the surface of the substrate (110) of the element part.

[0044] [2.1. Layer Structure of the Bag Layer]

[0045] In the packaging layer, the organic packaging layer and the inorganic packaging layer are typically directly laminated without interposing another layer between the organic packaging layer and the inorganic packaging layer. In the case where the packaging layer is a multilayer structure in which two or more organic packaging layers and two or more inorganic packaging layers are alternately laminated, the multilayer structure includes at least a structure in which one organic packaging layer and one inorganic packaging layer are directly laminated. In the present embodiment, it is preferable that the organic packaging layer and the inorganic packaging layer included in the multilayer structure are each directly laminated.

[0046] In the case of a multilayer structure in which two or more organic bag layers and two or more inorganic bag layers are alternately stacked, the number of organic bag layers and inorganic bag layers may be equal, and although not illustrated, the number of organic bag layers may be one layer greater than the number of inorganic bag layers, or the number of organic bag layers may be one layer less than the number of inorganic bag layers. The number of organic bag layers is, for example, two or more layers, preferably three or more layers, and preferably ten or fewer layers. The number of inorganic bag layers is, for example, two or more layers, preferably three or more layers, and preferably ten or fewer layers.

[0047] The specific layer structure of the encapsulation layer can be appropriately selected according to the device structure. For example, as shown in FIG. 1, the encapsulation layer (200) may have a structure in which a first encapsulation layer (201), a second encapsulation layer (202), and a third encapsulation layer (203) are stacked in this order with respect to the device part (120). In this case, the encapsulation layer (200) may have, for example, a second encapsulation layer (202) as an inorganic encapsulation layer (220) and a third encapsulation layer (203) as an organic encapsulation layer (210). In the case of having a second bag layer (202) as an inorganic bag layer (220) and a third bag layer (203) as an organic bag layer (210), it is preferable to have two or more layers of the second bag layer (202) and two or more layers of the third bag layer (203), and to have a structure in which the second bag layer (202) and the third bag layer (203) are alternately stacked. This is because the bagging performance of the bag layer (200) can be improved.

[0048] As shown in FIG. 1, when the encapsulation layer has a structure in which a first encapsulation layer, a second encapsulation layer, and a third encapsulation layer are stacked in this order with respect to the device part, the first encapsulation layer may be, for example, an organic encapsulation layer. Additionally, the first encapsulation layer may be, for example, a silicon encapsulation layer. Inorganic encapsulation layers containing silicon nitride tend to increase stress under high temperature and high humidity environments, making them prone to cracking. Therefore, when the second encapsulation layer is an inorganic encapsulation layer, if an organic encapsulation layer or a silicon encapsulation layer is used as the first encapsulation layer, the stress of the inorganic encapsulation layer can be absorbed to suppress the occurrence of cracks. Since the first encapsulation layer can directly encapsulate the device part, it is desirable to select a material by considering the influence on the device part during the formation of the first encapsulation layer, depending on the type of device part.

[0049] In addition to the layer structure described above, the layer structure that the encapsulation layer can take includes, for example, a two-layer structure in which an organic encapsulation layer and an inorganic encapsulation layer are stacked in this order with respect to the device part, and a three-layer structure in which an organic encapsulation layer, an inorganic encapsulation layer, and an organic encapsulation layer are stacked in this order with respect to the device part.

[0050] [2.2. Organic Bag Layer]

[0051] The organic encapsulation layer is a layer containing a thermoplastic elastomer. In addition, the organic encapsulation layer has a residue rate of 90% or more in a dissolution test for dibutyl ether.

[0052] In a dissolution test for dibutyl ether, the residual film rate of the organic encapsulant is a value obtained by the following measurement method. First, the organic encapsulant is exposed to the surface of a device structure and immersed in dibutyl ether for 60 seconds. Afterward, it is air-dried. The thickness of the organic encapsulant before immersion in dibutyl ether is denoted as T1, and the thickness of the organic encapsulant after immersion in dibutyl ether and air-drying is denoted as T2, and the ratio of T2 to the thickness T1 is defined as the residual film rate.

[0053] The residual film rate of the organic bag layer is 90% or more, preferably 95% or more, more preferably 98% or more, and ideally 100%.

[0054] The organic encapsulation layer is a layer formed on the device side rather than the inorganic encapsulation layer. Since the organic encapsulation layer has high resistance to dibutyl ether, damage to the organic encapsulation layer can be suppressed when the inorganic encapsulation layer is formed using a liquid composition containing a polysilazane compound and dibutyl ether. Additionally, the organic encapsulation layer may be formed directly on the surface of the device part, or it may be formed with another layer interposed on the surface of the device part. When the organic encapsulation layer is formed directly on the surface of the device part, the organic encapsulation layer can directly encapsulate the device part. Here, "direct" encapsulation of the device part by the layer means that there is no other layer between the layer and the device part.

[0055] [2.2.1. Materials of the Organic Bag Layer]

[0056] (Thermoplastic elastomer)

[0057] A thermoplastic elastomer refers to a material that exhibits rubber-like properties at room temperature and becomes plasticized at high temperatures, allowing for molding and processing. Such thermoplastic elastomers possess characteristics that make it difficult for elongation or fracture to occur under small force loads. Specifically, at 23°C, thermoplastic elastomers can exhibit a Young's modulus of 0.001 to 1 GPa and a tensile elongation (elongation at break) of 100 to 1000%. Furthermore, in a high temperature range of 40°C to 200°C, the storage modulus of thermoplastic elastomers may rapidly decrease, causing the loss tangent tanδ (loss modulus / storage modulus) to peak or exceed a value of 1, thereby softening. Young's modulus and tensile elongation can be measured according to JIS K7113. Additionally, the loss tangent tanδ can be measured by a commercially available dynamic viscoelasticity measuring device.

[0058] Thermoplastic elastomers generally do not contain residual solvent, or if they do, the amount is small. Therefore, thermoplastic elastomers have the advantages of low outgassing and the ability to perform encapsulation through a simple process that does not involve crosslinking.

[0059] Polymers may be used as thermoplastic elastomers. Examples of polymers that can be used as thermoplastic elastomers include ethylene-α-olefin copolymers such as ethylene-propylene copolymer; ethylene-α-olefin-polyene copolymers; copolymers of ethylene and unsaturated carboxylic acid esters such as ethylene-methyl methacrylate copolymer and ethylene-butyl acrylate copolymer; copolymers of ethylene and vinyl fatty acid such as ethylene-vinyl acetate copolymer; polymers of alkyl acrylate esters such as ethyl acrylate, butyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, and lauryl acrylate; Diene copolymers such as polybutadiene, polyisoprene, acrylonitrile-butadiene copolymer, butadiene-isoprene copolymer, butadiene-(meth)acrylate alkyl ester copolymer, butadiene-(meth)acrylate alkyl ester-acrylonitrile copolymer, butadiene-(meth)acrylate alkyl ester-acrylonitrile-styrene copolymer; butylene-isoprene copolymer; aromatic vinyl compound-conjugated diene copolymers such as styrene-butadiene random copolymer, styrene-isoprene random copolymer, styrene-butadiene block copolymer, styrene-butadiene-styrene block copolymer, styrene-isoprene block copolymer, styrene-isoprene-styrene block copolymer; Examples include hydrogenated aromatic vinyl compound-conjugated diene copolymers such as hydrogenated styrene-butadiene random copolymer, hydrogenated styrene-isoprene random copolymer, hydrogenated styrene-butadiene block copolymer, hydrogenated styrene-butadiene-styrene block copolymer, hydrogenated styrene-isoprene block copolymer, hydrogenated styrene-isoprene-styrene block copolymer, etc.; low-crystalline polybutadiene; styrene-grafted ethylene-propylene elastomer; thermoplastic polyester elastomer; and ethylene-based ionomer. One type of thermoplastic elastomer may be used alone, or two or more types may be used in combination in any ratio.

[0060] As a thermoplastic elastomer, a hydrogenated aromatic vinyl compound-conjugated diene block copolymer is preferred to obtain the desired effects of the present invention. A hydrogenated aromatic vinyl compound-conjugated diene block copolymer refers to a hydride of an aromatic vinyl compound-conjugated diene block copolymer. That is, a hydrogenated aromatic vinyl compound-conjugated diene block copolymer refers to a polymer having a structure obtained by hydrogenating the non-aromatic carbon-carbon unsaturated bonds, aromatic carbon-carbon bonds, or part or all of both of the aromatic vinyl compound-conjugated diene block copolymer. However, the above hydride is not limited by its manufacturing method.

[0061] As aromatic vinyl compounds, styrene and its derivatives; and vinylnaphthalene and its derivatives are preferred. Using styrene is particularly preferred due to its ease of industrial availability. Meanwhile, as conjugated dienes, chain-type conjugated dienes (straight-chain conjugated dienes, branched-chain conjugated dienes) are preferred. Preferred examples of conjugated dienes include 1,3-butadiene, isoprene (2-methyl-1,3-butadiene), 2,3-dimethyl-1,3-butadiene, and 1,3-pentadiene. Among these, 1,3-butadiene and isoprene are particularly preferred due to their ease of industrial availability.

[0062] When the mass fraction of the total aromatic vinyl monomer units in the total aromatic vinyl compound-conjugated diene block copolymer is denoted as wA, and the mass fraction of the total conjugated diene monomer units in the total aromatic vinyl compound-conjugated diene block copolymer is denoted as wB, the ratio of wA to wB (wA / wB) is preferably within a specific range. Specifically, the above ratio (wA / wB) is preferably 20 / 80 or higher, more preferably 30 / 70 or higher, preferably 60 / 40 or lower, and more preferably 55 / 45 or lower. If the above ratio wA / wB is greater than or equal to the lower limit of the above range, the heat resistance of the organic encapsulation layer can be improved. Furthermore, if it is less than or equal to the upper limit, the flexibility of the organic encapsulation layer can be increased. Additionally, if the above ratio (wA / wB) is within the above range, the temperature range in which the organic encapsulation layer exhibits rubber elasticity can be expanded, thereby expanding the temperature range in which the device structure exhibits flexibility.

[0063] As for the aromatic vinyl compound-conjugated diene block copolymer, a polymer selected from styrene-butadiene block copolymer, styrene-butadiene-styrene block copolymer, styrene-isoprene block copolymer, styrene-isoprene-styrene block copolymer, and mixtures thereof is preferred. More specific examples of these include those described in technical literature such as Japanese Patent Publication No. Hei 2-133406, Japanese Patent Publication No. Hei 2-305814, Japanese Patent Publication No. Hei 3-72512, Japanese Patent Publication No. Hei 3-74409, and International Publication No. 2015 / 099079.

[0064] The hydrogenation rate of the hydrogenated aromatic vinyl compound-conjugated diene block copolymer is preferably 90% or more, more preferably 97% or more, and particularly preferably 99% or more. The higher the hydrogenation rate, the better the heat resistance and light resistance of the organic encapsulation layer can be. The hydrogenation rate of the hydride can be determined by measurement using 1H-NMR.

[0065] The hydrogenation rate of the non-aromatic carbon-carbon unsaturated bonds of the hydrogenated aromatic vinyl compound-conjugated diene block copolymer is preferably 95% or more, more preferably 99% or more. When the hydrogenation rate of the non-aromatic carbon-carbon unsaturated bonds is high, the light resistance and oxidation resistance of the organic encapsulation layer can be further increased.

[0066] The hydrogenation rate of the aromatic carbon-carbon unsaturated bonds of the hydrogenated aromatic vinyl compound-conjugated diene block copolymer is preferably 90% or more, more preferably 93% or more, and particularly preferably 95% or more. When the hydrogenation rate of the aromatic carbon-carbon unsaturated bonds is high, the glass transition temperature of the hydride increases, so the heat resistance of the organic encapsulation layer can be effectively increased. In addition, the photoelastic modulus of the organic encapsulation layer can be lowered, thereby reducing the occurrence of retardation.

[0067] It is particularly desirable that the hydrogenated aromatic vinyl compound-conjugated diene block copolymer has a structure in which both the non-aromatic carbon-carbon unsaturated bonds and the aromatic carbon-carbon unsaturated bonds are hydrogenated.

[0068] Particularly preferred block forms of the hydrogenated aromatic vinyl compound-conjugated diene block copolymer are a triblock copolymer in which a block [A] of aromatic vinyl polymer hydride is bonded to both ends of a block [B] of conjugated diene polymer hydride; and a pentablock copolymer in which a polymer block [B] is bonded to both ends of a polymer block [A], and a polymer block [A] is bonded to the other end of each of the polymer blocks [B]. In particular, a [A]-[B]-[A] triblock copolymer is particularly preferred because it is easy to manufacture and allows for the properties as a thermoplastic elastomer to be within the desired range.

[0069] Hydrogenated aromatic vinyl compound-conjugated diene block copolymers can be manufactured, for example, by the method described in International Publication No. 2015 / 099079 and Japanese Patent Publication No. 2016-204217.

[0070] In addition, as a thermoplastic elastomer, a polymer having silicon atom-containing polar groups may be used. Examples of such polymers include modified products of the polymers exemplified as being usable as thermoplastic elastomers, which have silicon atom-containing polar groups. When a polymer having silicon atom-containing polar groups is adopted as a thermoplastic elastomer, the adhesion between the organic encapsulation layer and other members can be improved.

[0071] Hereinafter, the polymer used in the reaction to obtain the above-mentioned modified product may be appropriately referred to as the "pre-reaction polymer." The above-mentioned modified product may have a structure obtained, for example, by graft polymerization of the pre-reaction polymer and a compound having a silicon atom-containing polar group as a monomer. However, the modified product is not limited by its manufacturing method.

[0072] As for the silicon atom-containing polar group, an alkoxysilyl group is preferred. Examples of compounds having an alkoxysilyl group as a silicon atom-containing polar group include, for instance, ethylenically unsaturated silane compounds such as vinyltrimethoxysilane, vinyltriethoxysilane, allyltrimethoxysilane, allyltriethoxysilane, dimethoxymethylvinylsilane, diethoxymethylvinylsilane, p-stylyltrimethoxysilane, p-stylyltriethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-acryloxypropyltrimethoxysilane, and 2-norbornene-5-yltrimethoxysilane.

[0073] By reacting a polymer before reaction with a compound having a silicon atom-containing polar group, a silicon atom-containing polar group is introduced into the polymer before reaction, thereby obtaining a modified product having a silicon atom-containing polar group. When an alkoxysilyl group is introduced as the silicon atom-containing polar group, the amount of the alkoxysilyl group introduced is preferably 0.1 parts by weight or more, more preferably 0.2 parts by weight or more, even more preferably 0.3 parts by weight or more, and preferably 10 parts by weight or less, more preferably 5 parts by weight or less, and even more preferably 3 parts by weight or less, based on 100 parts by weight of the polymer before reaction. When the amount of the alkoxysilyl group introduced falls within the above range, the degree of crosslinking between alkoxysilyl groups decomposed by water can be suppressed from becoming excessively high, so high adhesion can be maintained. Examples of a material having an alkoxysilyl group used for introducing the alkoxysilyl group and a modification method include those described in International Publication No. 2015 / 099079.

[0074] The amount of polar group introduction can be measured using a 1H-NMR spectrum. Additionally, when measuring the amount of polar group introduction, if the amount is small, the number of integration cycles can be increased for measurement.

[0075] Among the thermoplastic elastomers described above, in order to significantly obtain the desired effects of the present invention, it is preferable to select at least one type from the group consisting of hydrogenated aromatic vinyl compound-conjugated diene block copolymers and modified products of hydrogenated aromatic vinyl compound-conjugated diene block copolymers containing silicon atoms. Among these, modified products of hydrogenated aromatic vinyl compound-conjugated diene block copolymers containing silicon atoms are particularly preferred.

[0076] Among modified products of hydrogenated aromatic vinyl compounds-conjugated diene block copolymers by silicon atom-containing polar groups, a modified product in which an alkoxysilyl group is introduced as a silicon atom-containing polar group is preferred. Generally, introducing an alkoxysilyl group as a polar group into a pre-reaction polymer, such as a hydrogenated aromatic vinyl compound-conjugated diene block copolymer, is sometimes referred to as silane modification. During silane modification, the alkoxysilyl group may be directly bonded to the pre-reaction polymer, or it may be bonded through a divalent organic group, such as an alkylene group. Hereinafter, the polymer obtained by silane modification of the pre-reaction polymer is also referred to as a "silane modified product."

[0077] Accordingly, as a modified product by a silicon atom-containing polar group of a hydrogenated aromatic vinyl compound-conjugated diene block copolymer, a silane modified product of a hydrogenated aromatic vinyl compound-conjugated diene block copolymer is preferred. Among these, one or more silane modified products selected from the group consisting of a silane modified product of a hydrogenated styrene-butadiene block copolymer, a silane modified product of a hydrogenated styrene-butadiene-styrene block copolymer, a silane modified product of a hydrogenated styrene-isoprene block copolymer, and a silane modified product of a hydrogenated styrene-isoprene-styrene block copolymer are particularly preferred.

[0078] The weight average molecular weight (Mw) of the thermoplastic elastomer is not particularly limited, but is preferably 20,000 or more, more preferably 30,000 or more, even more preferably 35,000 or more, preferably 200,000 or less, more preferably 100,000 or less, and even more preferably 70,000 or less. The weight average molecular weight of the thermoplastic elastomer can be measured as a polystyrene equivalent value by gel permeation chromatography using tetrahydrofuran as a solvent. In addition, the molecular weight distribution (Mw / Mn) of the thermoplastic elastomer is preferably 4 or less, more preferably 3 or less, even more preferably 2 or less, and preferably 1 or more. When the weight average molecular weight Mw and the molecular weight distribution Mw / Mn of the thermoplastic elastomer are within the above ranges, the mechanical strength and heat resistance of the organic encapsulation layer can be improved.

[0079] The glass transition temperature of the thermoplastic elastomer is not particularly limited, but is preferably 40°C or higher, more preferably 70°C or higher, preferably 200°C or lower, more preferably 180°C or lower, and even more preferably 160°C or lower. In addition, when a block copolymer is used as the thermoplastic elastomer, the glass transition temperature can be adjusted by changing the weight ratio of each polymer block to balance the adhesion and flexibility of the organic encapsulation layer. The glass transition temperature of the resin can be measured by increasing the temperature at a rate of 10°C / min using a differential scanning calorimeter (DSC).

[0080] (Arbitrary component)

[0081] The organic encapsulation layer may include any additional components in addition to the thermoplastic elastomer. Examples of such components include hygroscopic particles and ultraviolet absorbers.

[0082] Hygroscopic particles refer to particles that have a high weight change rate when left standing for 24 hours at 20°C and 90% RH. The specific range of the above weight change rate is typically 3% or more, preferably 10% or more, and more preferably 15% or more. There is no specific limit on the upper limit of the weight change rate, but it may be, for example, 100% or less. Since hygroscopic particles having such high hygroscopicity can absorb a large amount of moisture with a small amount, they can effectively suppress moisture from penetrating the encapsulation layer. As a result, it is advantageous that the rubber properties of the thermoplastic elastomer are not impaired.

[0083] The weight change rate of hygroscopic particles can be calculated by the following equation (K1). In the following equation (K1), W1 represents the weight of the particles before being placed in an environment of 20°C and 90% Rh, and W2 represents the weight of the particles after being placed in an environment of 20°C and 90% Rh for 24 hours.

[0084] Weight change rate (%) = ((W2 - W1) / W1) × 100 (K1)

[0085] Examples of materials contained in hygroscopic particles include basic hygroscopic materials and acidic hygroscopic materials. Examples of basic hygroscopic materials include compounds (oxides, hydroxides, salts, etc.) containing alkali metals, alkaline earth metals, and aluminum that do not contain silicon (e.g., barium oxide, magnesium oxide, calcium oxide, strontium oxide, aluminum hydroxide, hydrotalcite, etc.); organometallic compounds described in Japanese Patent Publication No. 2005-298598; clay containing metal oxides; etc. Additionally, examples of acidic hygroscopic materials include inorganic compounds containing silicon (e.g., silica gel, nanoporous silica, zeolite).

[0086] As the material for the hygroscopic particles, one or more materials selected from the group consisting of zeolites and hydrotalcites are preferred. Among these, zeolites generally possess particularly high hygroscopic capacity. Specifically, zeolites can easily achieve a high weight change rate of 10% to 30% when left standing for 24 hours at 20°C and 90% RH. In addition, zeolites can be reused as they release water upon drying. As the material for the hygroscopic particles, one type may be used alone, or two or more types may be used in combination in any ratio.

[0087] The primary particle size of the hygroscopic particles is preferably 30 nm or more, more preferably 40 nm or more, preferably 150 nm or less, and more preferably 80 nm or less. The primary particle size of the hygroscopic particles refers to the number-average particle size of the primary particles. The primary particle size of the hygroscopic particles can be measured by a particle size measuring device based on dynamic light scattering in the state of a dispersion solution dispersed in a solvent. If the primary particle size of the hygroscopic particles cannot be measured by dynamic light scattering, the primary particle size may be measured by observation using an electron microscope. Specifically, it can be measured by the following method. By observation using an electron microscope, the sum of the minor and major axes of each of the 50 primary particles is calculated, and the obtained sum is divided by 2 to measure the particle size of each particle. The arithmetic mean of the particle sizes of the 50 primary particles measured in this way can be taken as the primary particle size. When determining the primary particle size by observation using an electron microscope, the particles in the cross-section of the organic encapsulation layer may be observed.

[0088] The refractive index of the hygroscopic particles at a measurement wavelength of 589 nm is preferably 1.2 or higher and 3.0 or lower. When hygroscopic particles having such a refractive index are used, the haze of the organic encapsulation layer is reduced, and an encapsulation layer with excellent transparency can be realized.

[0089] The proportion of hygroscopic particles in the organic bag layer is not particularly limited and can be adjusted to a range where desired properties are obtained. Specifically, the proportion of hygroscopic particles in the organic bag layer is preferably 5 weight% or more, more preferably 10 weight% or more, preferably 60 weight% or less, preferably 40 weight% or less, and more preferably 30 weight% or less. By having the proportion of hygroscopic particles above the above lower limit, the effect of inhibiting moisture penetration of the organic bag layer can be enhanced. In addition, by having the proportion of hygroscopic particles below the above upper limit, the transparency of the organic bag layer can be enhanced.

[0090] Examples of UV absorbers include organic UV absorbers such as benzotriazole-based UV absorbers, triazine-based UV absorbers, benzophenone-based UV absorbers, acrylonitrile-based UV absorbers, salicylate-based UV absorbers, cyanoacrylate-based UV absorbers, azomethine-based UV absorbers, indole-based UV absorbers, naphthalimide-based UV absorbers, and phthalocyanine-based UV absorbers. In the present embodiment, it is preferable to include one or more selected from the group consisting of benzotriazole-based UV absorbers and triazine-based UV absorbers.

[0091] Benzotriazole-based ultraviolet absorbers contain a benzotriazole structure within their molecules. Examples of benzotriazole-based ultraviolet absorbers include 2,2'-methylenebis[6-(2H-benzotriazole-2-yl)-4-(1,1,3,3-tetramethylbutyl)phenol], 2-(2H-benzotriazole-2-yl)-p-cresol, and 2-(5-chloro-2H-benzotriazole-2-yl)-6-tert-butyl-4-methylphenol. Examples of commercially available benzotriazole-based ultraviolet absorbers include "Adecastav LA-31", "Adecastav LA-32", and "Adecastav LA-36" manufactured by ADEKA.

[0092] Triazine-based UV absorbers contain a triazine structure within their molecules. As a triazine-based UV absorber, a compound containing a 1,3,5-triazine structure within its molecule is preferred. Examples of triazine-based UV absorbers include 2,4,6-tris(2-hydroxy-3-methyl-4-hexyloxyphenyl)-1,3,5-triazine, 2-(4,6-diphenyl-1,3,5-triazine-2-yl)-5-(2-(2-ethylhexanoyloxy)ethoxy)phenol, and 2,4-diphenyl-6-(2-hydroxy-4-hexyloxyphenyl)-1,3,5-triazine. Examples of commercially available triazine-based UV absorbers include "Adecastav LA-F70" and "Adecastav LA-46" manufactured by ADEKA, and "Tinuvine 1577" manufactured by BASF Japan. Another specific example of a UV absorber is the UV absorber described in Japanese Patent Publication No. 2017-154401.

[0093] Any component that may be included in the resin composition may include, in addition to the hygroscopic particles and ultraviolet absorbers mentioned above, dispersants, plasticizers, light stabilizers, antioxidants, lubricants, inorganic fillers, etc. Regarding the type, characteristics, and amount of any of these components, those described in, for example, International Publication No. 2019 / 220896 may be adopted.

[0094] Any component may be used as a single type, or two or more types may be combined in any ratio.

[0095] [2.2.2. Physical Properties of Organic Encapsulation Layer]

[0096] The thickness of the organic encapsulation layer is preferably 1 nm or more, more preferably 10 nm or more, even more preferably 80 nm or more, preferably 300 nm or less, more preferably 200 μm or less, and particularly preferably 150 μm or less. When the thickness of the organic encapsulation layer is greater than or equal to the lower limit value, the intrusion of moisture can be effectively suppressed. In addition, when the thickness of the organic encapsulation layer is less than or equal to the upper limit value, the thickness of the device structure can be reduced. Here, the thickness of the organic encapsulation layer refers to the thickness per layer of the organic encapsulation layer.

[0097] The haze of the organic encapsulation layer is preferably 0.5% or less, more preferably 0.15% or less, and particularly preferably 0.05% or less. When the haze is below the above range, the transparency of the organic encapsulation layer can be increased, so it can be suitably used in locations where light transmission is required in device structures such as organic electroluminescence devices and flexible touch sensors. The haze can be measured by using a turbidimeter.

[0098] [2.3. Inorganic Bag Layer]

[0099] The inorganic encapsulation layer is a layer containing silicon nitride. In addition to silicon nitride, the inorganic encapsulation layer may also contain, for example, silicon oxide and silicon oxynitride.

[0100] Such an inorganic encapsulation layer can be formed using a polysilazane compound. More specifically, it can be formed by using the formation method described in [II. Method for Manufacturing Device Structure] below.

[0101] The thickness of the inorganic encapsulation layer is preferably 1 nm or more, more preferably 10 nm or more, preferably 300 nm or less, more preferably 200 nm or less, and particularly preferably 150 nm or less. When the thickness of the inorganic encapsulation layer is greater than or equal to the lower limit value, the intrusion of moisture can be effectively suppressed. In addition, when the thickness of the inorganic encapsulation layer is less than or equal to the upper limit value, the thickness of the device structure can be reduced. Here, the thickness of the inorganic encapsulation layer refers to the thickness per layer of the inorganic encapsulation layer.

[0102] [2.4. Silicone Encapsulation Layer]

[0103] The encapsulation layer according to the present embodiment may have, for example, a silicone encapsulation layer in addition to the organic encapsulation layer and inorganic encapsulation layer described above. The silicone encapsulation layer comprises, for example, a compound having a siloxane whose main backbone consists of Si-O bonds with high bonding energy, and more specifically, an organopolysiloxane. As an organopolysiloxane, dimethylpolysiloxane may be cited as an example. Furthermore, the silicone encapsulation layer is preferably a silicone rubber (silicone elastomer). The thickness of the silicone encapsulation layer is preferably 1 nm or more, more preferably 10 nm or more, even more preferably 80 nm or more, preferably 300 nm or less, and more preferably 200 nm or less.

[0104] [2.5. Bag Layer]

[0105] The total thickness of the encapsulation layer is appropriately adjusted within a range that allows it to exhibit desired encapsulation performance as an encapsulation layer of a device structure. The total thickness of the encapsulation layer is preferably 0.7 μm or more, more preferably 1 μm or more, preferably 10 μm or less, and more preferably 5 μm or less. The encapsulation layer according to the present embodiment has a structure in which the above-mentioned organic encapsulation layer and inorganic encapsulation layer are laminated, thereby enabling it to exhibit good encapsulation performance with a thin thickness.

[0106] The thickness of each constituent layer constituting the encapsulation layer is preferably 300 nm or less, and preferably 200 nm or less. In addition, the lower limit of the thickness of each constituent layer can be, for example, 1 nm or more.

[0107] [3. Device Structure]

[0108] As in the embodiment described above, the device structure (10) having an organic electroluminescence element part as the element part (120) can be used as a device such as a display device or a lighting device. However, the device structure is not limited to these devices. The device structure may include a wide range of devices having an element part and assemblies constituting a part of the device. Among these, since the encapsulation layer of the device structure described above has excellent transparency, various optical devices and assemblies constituting a part of the optical device are preferred as the device structure. Examples of optical devices include liquid crystal display devices, touch panels, and organic electroluminescence devices as display devices and light source devices. In particular, by utilizing the excellent characteristic of the organic electroluminescence element part being flexible, it is preferable to use the device structure as a flexible optical device.

[0109] [II. Method for Manufacturing Device Structure]

[0110] A method for manufacturing a device structure according to one embodiment of the present invention comprises a process (a) of preparing a multilayer having a substrate and a device portion formed on the substrate, and a process (b) of forming an encapsulation layer that encapsulates the device portion, wherein the process (b) of forming the encapsulation layer comprises a process (b1) of forming an organic encapsulation layer and a process (b2) of forming an inorganic encapsulation layer after the process (b1), wherein the process (b1) comprises a process (b1-1) of forming an organic intermediate layer comprising a thermoplastic elastomer and a process (b1-2) of obtaining the organic encapsulation layer by irradiating the organic intermediate layer with vacuum ultraviolet light, and wherein the process (b2) comprises a process (b2-1) of forming an intermediate layer using a liquid composition comprising a polysilazane compound and a solvent, and a process (b2-2) of obtaining an inorganic encapsulation layer comprising silicon nitride by irradiating the intermediate layer with ultraviolet light.

[0111] FIGS. 2 to 6 are cross-sectional views illustrating a method for manufacturing a device structure according to an embodiment of the present invention. FIGS. 2 to 6 illustrate an example in which, in the process (b) of forming an encapsulation layer (200), a first encapsulation layer (201), a second encapsulation layer (202), a third encapsulation layer (203), a second encapsulation layer (202), and a third encapsulation layer (203) are stacked in this order on a device portion (120). In the method for manufacturing a device structure (10) in this example, as shown in FIG. 2, a multilayer (100) having a substrate (110) and a device portion (120) formed on the substrate (110) is prepared (process (a)). Next, as shown in FIG. 3, a first encapsulation layer (201) is formed on the device portion (120) (process (b3)). FIG. 3 illustrates an example in which a silicone encapsulation layer (230) is formed as the first encapsulation layer (201). Next, as shown in FIG. 4, a second encapsulation layer (202) as an inorganic encapsulation layer (220) is formed on the first encapsulation layer (201) (Process (b4)). Next, as shown in FIG. 5, a third encapsulation layer (203) as an organic encapsulation layer (210) is formed on the second encapsulation layer (202) (Process (b5)). Next, as shown in FIG. 6, the encapsulation layer (200) is formed by further repeating the above process (b4) and the above process (b5).

[0112] In the method for manufacturing a device structure according to the present embodiment, in process (b1), vacuum ultraviolet light is irradiated onto the organic intermediate layer, thereby improving the resistance of the organic encapsulation layer to the solvent of the polysilazane compound. Accordingly, when forming an inorganic encapsulation layer on the organic encapsulation layer, the deterioration of the organic encapsulation layer due to the solvent of the polysilazane compound can be suppressed, and an encapsulation layer with good encapsulation performance can be formed.

[0113] The inventors speculate as follows regarding the reason why the resistance of a polysilazane compound to solvents can be improved by irradiating an organic encapsulation layer with vacuum ultraviolet light. However, the technical scope of the present invention is not limited by the following structure.

[0114] It is presumed that when a liquid composition containing a polysilazane compound and a solvent is coated onto an organic encapsulation layer, damage occurs as the solvent penetrates into the organic encapsulation layer. In contrast, it is presumed that damage is suppressed because irradiating the organic encapsulation layer with vacuum ultraviolet light densifies the surface of the organic encapsulation layer, making it difficult for the solvent to penetrate.

[0115] [1. Process(a): Preparation of multilayer structures]

[0116] Process (a) is a process for preparing a multilayer. The multilayer may be prepared by manufacturing it yourself or by purchasing it from another person. The multilayer is prepared in the same manner as described in item [I. Device Structure 1. Multilayer] above.

[0117] [2. Process(b): Formation of the bag layer]

[0118] The process (b) for forming a bag layer includes a process (b1) for forming an organic bag layer and, after process (b1), a process (b2) for forming an inorganic bag layer. In process (b), at least the process (b1) and process (b2) are performed in this order. Since it is preferable for the bag layer to have a structure in which two or more organic bag layers and two or more inorganic bag layers are alternately stacked, it is preferable for process (b1) and process (b2) to be repeated two or more times. In this case, process (b1) and process (b2) may be repeated in this order, or process (b2) and process (b1) may be repeated in this order.

[0119] [2.1. Process (b1): Formation of organic encapsulation layer]

[0120] The process of forming an organic encapsulation layer includes a process (b1-1) of forming an organic intermediate layer comprising a thermoplastic elastomer, and a process (b1-2) of obtaining the organic encapsulation layer by irradiating the organic intermediate layer with vacuum ultraviolet light.

[0121] [2.1.1. Process (b1-1): Formation of organic intermediate layer]

[0122] Process (b1-1) is a process for forming an organic intermediate layer containing a thermoplastic elastomer. The organic intermediate layer is a layer of a resin composition containing a thermoplastic elastomer, which is obtained in the stage prior to irradiation with vacuum ultraviolet light.

[0123] Preferably, the method for forming an organic intermediate layer is a process of obtaining an organic intermediate layer by forming a layer of a resin composition comprising a thermoplastic elastomer and a solvent, and then drying the layer of the resin composition. Hereinafter, the solvent included in the resin composition may be referred to as the "first solvent" to distinguish it from the solvent used when forming the inorganic encapsulation layer.

[0124] The resin composition comprises a thermoplastic elastomer and a first solvent. It is preferable that the resin composition comprises any component. The thermoplastic elastomer and any component are described in the same manner as described in [I. Device Structure 2. Encapsulation Layer 2.2. Organic Encapsulation Layer] above.

[0125] As the first solvent, a solvent capable of dissolving or dispersing a thermoplastic elastomer may be used. Additionally, the first solvent may be used as a single type or as a combination of two or more types. Among these, since the device portion to be encapsulated generally has low resistance to moisture, it is preferable to use a non-aqueous solvent as the first solvent. Furthermore, from the perspective of suppressing damage to the device portion and effectively suppressing the intrusion of moisture, it is preferable to use a non-polar solvent as the first solvent.

[0126] Examples of non-polar solvents include organic solvents such as cyclohexane, methylcyclohexane, ethylcyclohexane, hexane, toluene, benzene, xylene, decahydronaphthalene, tetrahydronaphthalene, trimethylbenzene, cyclooctane, cyclodecane, octane (e.g., normal octane), dodecane, tridecane, tetradecane, and cyclododecane.

[0127] The amount of non-polar solvent that makes up 100% by weight of the total amount of the first solvent is preferably 95% by weight or more, more preferably 99% by weight or more, even more preferably 99.9% by weight or more, and ideally 100% by weight.

[0128] The first solvent preferably comprises a high-boiling point solvent having a high boiling point. 1 atm (1.01325 × 10⁻⁶) of the high-boiling point solvent 5 The boiling point in Pa is preferably 90°C or higher, more preferably 100°C or higher, even more preferably 125°C or higher, even more preferably 150°C or higher, and particularly preferably 175°C or higher. When the first solvent includes a high-boiling-point solvent, the formation of non-uniformity on the surface of the organic encapsulation layer obtained by drying the organic intermediate layer as a layer of the resin composition containing the first solvent can be suppressed, thereby making the surface smooth. In addition, nozzle clogging during coating of the resin composition using an inkjet printing method can be suppressed. The upper limit of the boiling point of the high-boiling-point solvent at 1 atm is preferably 300°C or lower, more preferably 250°C or lower. When the boiling point of the high-boiling-point solvent is below the upper limit of the above range, drying of the organic intermediate layer can be performed easily.

[0129] With respect to the total amount of 100% by weight of the first solvent, the amount of the high-boiling point solvent is preferably 10% by weight or more, more preferably 25% by weight or more, even more preferably 50% by weight or more, even more preferably 70% by weight or more, particularly preferably 80% by weight or more, and typically 100% by weight or less.

[0130] Preferably, the resin composition is a liquid composition. By using a liquid resin composition, an organic intermediate layer can be simply formed by a coating method. The viscosity of this liquid resin composition is preferably 1 cP or more, more preferably 2 cP or more, particularly preferably 3 cP or more, preferably 5000 cP or less, more preferably 1000 cP or less, even more preferably 500 cP or less, even more preferably 50 cP or less, even more preferably 30 cP or less, and particularly preferably 20 cP or less. When the viscosity of the resin composition is above the lower limit of the above range, it is easy to adjust the thickness of the organic intermediate layer, so an organic encapsulation layer having a desired thickness can be simply formed. In addition, when the viscosity of the resin composition is below the upper limit of the above range, the formation of an organic intermediate layer by a coating method can be easily performed. In particular, when the viscosity is 50 cP or less, the formation of an organic intermediate layer by inkjet printing is possible. Viscosity can be measured using a tuning fork viscometer (e.g., the tuning fork viscometer SV-10 manufactured by A.N.D. Inc.) at a measurement temperature of 25°C ± 2°C.

[0131] The proportion of solids included in the resin composition is not particularly limited, and it is desirable to adjust it appropriately so that characteristics such as viscosity fall within a desired range. Specifically, the amount of solids relative to 100% by weight of the total resin composition is preferably 1% by weight or more, more preferably 3% by weight or more, preferably 40% by weight or less, more preferably 30% by weight or less, and even more preferably 20% by weight or less.

[0132] As a method for forming an organic intermediate layer, it is preferable to perform the above-mentioned resin composition comprising a thermoplastic elastomer and a first solvent, and to coat the resin composition. By doing so, an organic intermediate layer can be easily formed.

[0133] Examples of coating methods include curtain coating, extrusion coating, roll coating, spin coating, dip coating, bar coating, spray coating, slide coating, printing coating, gravure coating, die coating, gap coating, and dipping. Among these, printing methods such as screen printing and inkjet printing are preferred, and inkjet printing is particularly preferred.

[0134] When the layer of the resin composition contains a first solvent, the resin composition is coated and then dried to remove the first solvent. Examples of drying methods for the layer of the resin composition include natural drying, heat drying, vacuum drying, and vacuum heat drying. If natural drying is achieved simply by leaving it at room temperature for a short time, specific drying operations may be unnecessary. However, since the layer of the resin composition may contain a large amount of the first solvent, it is generally desirable to promote drying by operations such as heating or vacuuming. By drying the layer of the resin composition, the first solvent is removed from the layer of the resin composition, and an organic intermediate layer formed from the solid components of the resin composition is obtained.

[0135] [2.1.2. Process (b1-2): Vacuum UV Irradiation]

[0136] Process (b1-2) is a process of obtaining the organic encapsulation layer by irradiating the organic intermediate layer with vacuum ultraviolet light. By performing process (b1-2), the dibutyl ether resistance of the organic encapsulation layer can be improved.

[0137] For vacuum ultraviolet light, light with a wavelength of 100 nm to 200 nm can be used. Examples of light sources for vacuum ultraviolet light include noble gas excimer lamps. Among them, Xe excimer lamps have excellent luminous efficiency because they emit ultraviolet light with a short wavelength of 172 nm as a single wavelength.

[0138] The vacuum ultraviolet irradiation conditions can be appropriately adjusted to a range in which a desired organic encapsulation layer is obtained. In the present embodiment, it is preferable to use irradiation conditions that include a process (b1-2-1) of irradiating the organic intermediate layer with vacuum ultraviolet light under an inert gas atmosphere, and a process (b1-2-2) of irradiating the organic intermediate layer after the process (b1-2-1) with vacuum ultraviolet light under a mixed atmosphere of inert gas and oxygen. When vacuum ultraviolet light is irradiated under an inert gas atmosphere, solvent resistance can be imparted to the surface of the organic encapsulation layer, but wettability to the solvent tends to decrease, and the liquid composition tends to be easily repelled. Therefore, it is preferable to impart solvent resistance by irradiating vacuum ultraviolet light under an inert gas atmosphere, and then irradiate vacuum ultraviolet light under a mixed atmosphere of inert gas and oxygen to modify a portion of the surface of the organic encapsulation layer and improve its coating properties against the solvent.

[0139] The term "under an inert gas atmosphere" in process (b1-2-1) includes not only an atmosphere in which only inert gas exists, but also an atmosphere containing inert gas and a trace amount of oxygen. The specific oxygen concentration of the atmosphere under the inert gas atmosphere is preferably 500 ppm or more, more preferably 1000 ppm or more, preferably 10000 ppm or less, more preferably 5000 ppm or less. The unit "ppm" above is based on mass.

[0140] Examples of inert gases include nitrogen, helium, neon, and argon, among which nitrogen is preferred. Additionally, one type of inert gas may be used alone, or two or more types may be used in any combination. When using an inert gas, for example, ultraviolet irradiation may be performed in a treatment room where the inert gas is supplied and exhausted. At this time, in order to adjust the oxygen concentration in the atmosphere, the flow rates of the oxygen gas and inert gas introduced into the treatment room may be adjusted.

[0141] The irradiation intensity of vacuum ultraviolet light under an inert gas atmosphere can be appropriately adjusted to a range in which the desired organic encapsulation layer is obtained. To specify a range, the irradiation intensity is preferably 30 mW / cm². 2 Ideally, 40 mW / cm² 2 Ideally, 50 mW / cm² 2 Ideally, 100 mW / cm² 2 Below, more preferably 80 mW / cm 2 Below, more preferably 60 mW / cm 2 It is as follows.

[0142] The irradiation time of vacuum ultraviolet light under an inert gas atmosphere can be appropriately adjusted to a range in which a desired organic encapsulation layer is obtained. To specify a specific range, the irradiation time is preferably 100 seconds or more, more preferably 150 seconds or more, preferably 300 seconds or less, and more preferably 250 seconds or less.

[0143] The "mixed atmosphere of inert gas and oxygen" in process (b1-2-2) is an atmosphere containing inert gas and oxygen. The oxygen concentration can be adjusted to a level that changes the wettability of the surface of the organic encapsulation layer to the solvent. The specific oxygen concentration is preferably 1% or more, more preferably 3% or more, preferably 20% or less, and more preferably 10% or less. The unit "%" above is based on mass.

[0144] In addition, the irradiation intensity of vacuum ultraviolet light under a mixed atmosphere of inert gas and oxygen can be appropriately adjusted to a range in which the desired organic encapsulation layer is obtained. To specify a range, the irradiation intensity is preferably 30 mW / cm². 2 Ideally, 40 mW / cm² 2 Ideally, 50 mW / cm² 2 Ideally, 100 mW / cm² 2 Below, more preferably 80 mW / cm 2 Below, more preferably 60 mW / cm 2 It is as follows.

[0145] The irradiation time of vacuum ultraviolet light under a mixed atmosphere of inert gas and oxygen can be appropriately adjusted to a range in which a desired organic encapsulation layer is obtained. To specify a specific range, it is preferably 100 seconds or more, more preferably 150 seconds or more, preferably 300 seconds or less, and more preferably 250 seconds or less.

[0146] Irradiation conditions, such as the irradiation intensity and irradiation time of vacuum UV in process (b1-2), may be adjusted, for example, by the amount of reduction in the peak intensity of CH stretching origin in the FT-IR spectrum of the organic intermediate layer (organic encapsulation layer) before and after vacuum UV irradiation. Specifically, when the peak intensity of CH stretching origin in the FT-IR spectrum of the organic intermediate layer before vacuum UV irradiation is set to I1 and the peak intensity of CH stretching origin in the FT-IR spectrum of the organic intermediate layer after vacuum UV irradiation is set to I2, it is preferable to set the irradiation condition such that the ratio of I2 to I1 (I2 / I1) is 50% or less. In addition, it is preferable to set the irradiation condition such that I2 / I1 is 20% or more. This is because when I2 / I1 is within the above range, an organic encapsulation layer with good dibutyl ether resistance is easily obtained. The peak of CH stretching origin in the FT-IR spectrum is, for example, at 2960 cm⁻¹. -1 ~2850 cm -1 It is observed within the range of.

[0147] [2.2. Process (b2): Formation of inorganic encapsulation layer]

[0148] The process (b2) for forming an inorganic encapsulation layer comprises a process (b2-1) for forming an intermediate layer using a liquid composition containing a polysilazane compound and a solvent, and a process (b2-2) for obtaining an inorganic encapsulation layer containing silicon nitride by irradiating the intermediate layer with ultraviolet light. Since the inorganic encapsulation layer is formed on an organic encapsulation layer, the device part can be indirectly encapsulated. When the encapsulation layer has two or more inorganic encapsulation layers, for example, the inorganic encapsulation layer may be formed directly on the device part.

[0149] [2.2.1. Process (b2-1): Formation of the intermediate layer]

[0150] Process (b2) includes a process (b2-1) of forming an intermediate layer using a liquid composition comprising a polysilazane compound and a solvent. The intermediate layer is a layer containing a polysilazane compound.

[0151] The formation of an intermediate layer comprising the above-mentioned polysilazane compound is preferably carried out by a method comprising coating a liquid composition comprising a polysilazane compound and a solvent. According to this method, the intermediate layer can be easily formed.

[0152] Polysilazane compounds are polymers having silicon-nitrogen bonds. Examples of polysilazane compounds include SiO2, Si3N4, and the intermediate solid solution SiO2. x N y Polysilazane compounds that can be used as precursors for ceramics such as the above may be used.

[0153] Preferred polysilazane compounds include, for example, compounds containing repeating units represented by the following formula (1).

[0154] [Chemical Formula 1]

[0155]

[0156] In equation (1), R 1 , R 2 and R 3 Each represents one or more groups selected from the group consisting of a hydrogen atom and a monovalent organic group. Examples of monovalent organic groups include aliphatic hydrocarbon groups such as alkyl groups and alkenyl groups; alicyclic hydrocarbon groups such as cycloalkyl groups; aromatic hydrocarbon groups such as aryl groups; alkylsilyl groups; alkylamino groups; alkoxy groups; etc. As the polysilazane compound represented by Formula (1), the one described in Japanese Patent Publication No. Hei 8-112879 may be used.

[0157] Among them, from the perspective of obtaining an inorganic encapsulation layer with excellent encapsulation ability, R 1 , R 2 and R3 Hydrogen atoms are preferred. R in the repeating unit 1 , R 2 and R 3 Polysilazane compounds in which all atoms are hydrogen are sometimes called perhydropolysilazanes. The number average molecular weight (Mn) of perhydropolysilazanes can be, for example, about 600 to 2000 (polystyrene equivalent).

[0158] Other preferred polysilazane compounds include, for example, a silicon alkoxide-added polysilazane obtained by reacting a silicon alkoxide with a polysilazane compound containing repeating units represented by formula (1) (Japanese Patent Publication No. Hei 5-238827), a glycidol-added polysilazane obtained by reacting a glycidol (Japanese Patent Publication No. Hei 6-122852), an alcohol-added polysilazane obtained by reacting an alcohol (Japanese Patent Publication No. Hei 6-240208), a metal carboxylate-added polysilazane obtained by reacting a metal carboxylate (Japanese Patent Publication No. Hei 6-299118), an acetylacetonate complex-added polysilazane obtained by reacting a metal-containing acetylacetonate complex (Japanese Patent Publication No. Hei 6-306329), and a metal microparticle-added polysilazane obtained by adding metal microparticles (Japanese Patent Publication No. Examples include Pyeong 7-196986).

[0159] Polysilazane compounds may be used as a single type or in any combination of two or more types. For example, a combination of perhydropolysilazane and an organopolysilazane in which some of the hydrogen atoms bonded to the Si atoms of the perhydropolysilazane are substituted with organic groups such as alkyl groups may be used. When perhydropolysilazane and organopolysilazane are used in combination, the toughness of the second encapsulation layer can be increased, thereby enabling crack suppression. In particular, when an organopolysilazane substituted by a methyl group is used in combination with perhydropolysilazane, the toughness can be significantly increased.

[0160] In addition, only perhydropolysilazane may be used as the polysilazane compound. An inorganic encapsulation layer formed using only perhydropolysilazane tends to be particularly prone to cracking. In this embodiment, even when such an inorganic encapsulation layer prone to cracking is formed, cracking can be suppressed by combining it with an organic encapsulation layer.

[0161] Polysilazane compounds can generally be liquid or solid compounds. Commercially available polysilazane compounds may be used.

[0162] The liquid composition typically includes a solvent. Hereinafter, the solvent used to form the intermediate layer may be referred to as a "second solvent" to distinguish it from the first solvent used to form the organic intermediate layer. The second solvent is preferably a solvent containing dibutyl ether. The content of dibutyl ether in the second solvent is preferably 50 weight% or more, more preferably 70 weight% or more, and even more preferably 90 weight% or more. This is because, in process (b1), the dibutyl ether resistance of the organic encapsulation layer can be increased by irradiating with vacuum ultraviolet light, and thus, by including dibutyl ether as the second solvent, the effect according to the present embodiment can be highly exhibited.

[0163] Additionally, as the second solvent, a solvent in which the residual film rate of the organic encapsulation layer in the dissolution test of the second solvent is 90% or higher may be used. In order to select the second solvent, the present embodiment may include a process (b2-3) for selecting a second solvent in which the residual film rate of the organic encapsulation layer in the dissolution test of the second solvent is 90% or higher. In selecting the second solvent, for example, a sample in which an organic encapsulation layer is formed on a supporting substrate such as a silicon substrate under the same conditions as process (b1) may be prepared, and after irradiating with vacuum ultraviolet light, the sample may be immersed in the second solvent under the same conditions as the dissolution test of dibutyl ether described above and dried, and the residual film rate may be calculated from the thickness of the organic encapsulation layer before and after immersion, and a solvent in which the residual film rate is 90% or higher may be selected as the second solvent. The irradiation conditions for vacuum ultraviolet light are, for example, under an environment of a temperature of 23–25°C and a humidity of 50–60%, under an inert gas atmosphere (e.g., a nitrogen atmosphere), vacuum ultraviolet light (VUV (172 nm)) at an illuminance of 30 mW / cm² 2 It can be done on the condition that it is investigated for 3 minutes.

[0164] Examples of the second solvent include hydrocarbon solvents such as aliphatic hydrocarbons, alicyclic hydrocarbons, and aromatic hydrocarbons; halogenated hydrocarbon solvents; and ether solvents such as aliphatic ether solvents and alicyclic ether solvents. Specific examples include hydrocarbon solvents such as pentane, hexane, cyclohexane, toluene, xylene, sorbeso, and tabene; halogenated hydrocarbon solvents such as methylene chloride and trichloroethane; and ether solvents such as dibutyl ether, dioxane, and tetrahydrofuran. The second solvent may be used as a single type or two or more types may be used in combination in any ratio.

[0165] It is desirable to adjust the amount of the second solvent in the liquid composition so that the concentration of the polysilazane compound in the liquid composition falls within an appropriate range. Specifically, with respect to 100% by weight of the total amount of the liquid composition, the amount of the polysilazane compound is preferably 0.2% to 35% by weight.

[0166] The liquid composition may include any component other than the polysilazane compound and the second solvent.

[0167] There are no particular limitations on the coating method for the liquid composition. As an example of the coating method, the same method used for coating the resin composition used to form the organic intermediate layer may be used. Through such coating, an intermediate layer as a layer of the liquid composition can be formed under an atmospheric pressure environment.

[0168] Since the intermediate layer contains a second solvent, process (b2-1) may include a process (b2-4) for drying the intermediate layer. Drying may be performed simultaneously with process (b2-2), but it is preferable to perform it before process (b2-2). By drying, the second solvent can be removed from the intermediate layer.

[0169] It is preferable to dry the intermediate layer in an atmosphere with a low oxygen concentration. Specifically, the oxygen concentration of the atmosphere is preferably 10% or less, and more preferably 5% or less. By drying in such an atmosphere with a low oxygen concentration, the absorption of oxygen into the intermediate layer can be suppressed. Therefore, since the absorption of ultraviolet rays irradiated in process (b2-2) by oxygen can be suppressed, the reaction of the polysilazane compound can be carried out stably.

[0170] From the perspective of performing drying under an atmosphere with a low oxygen concentration, it is preferable to perform the drying of the intermediate layer under an inert gas atmosphere. Examples of inert gases include nitrogen, helium, neon, and argon, among which nitrogen is preferred. Furthermore, one type of inert gas may be used alone, or two or more types may be used in a combination of arbitrarily. When using an inert gas, drying may be performed, for example, in a drying chamber where the inert gas is supplied and exhausted. Additionally, heating may be performed during drying.

[0171] [2.2.2. Process (b2-2): Ultraviolet irradiation of the intermediate layer]

[0172] Process (b2) includes a process (b2-2) of irradiating the intermediate layer with ultraviolet light after obtaining the intermediate layer in process (b2-1). As ultraviolet light is irradiated onto the intermediate layer, the polysilazane compound contained in the intermediate layer reacts, thereby obtaining an inorganic encapsulation layer containing silicon nitride.

[0173] For ultraviolet light, light with a wavelength of 1 nm to 380 nm can be used. Among these, it is preferable to use vacuum ultraviolet light with a wavelength of 100 nm to 200 nm. By irradiating with vacuum ultraviolet light, the modification reaction of the polysilazane compound can be carried out in a short time, thereby suppressing damage to the device part and the organic encapsulation layer caused by ultraviolet light. The light source for the vacuum ultraviolet light is the same as described in the item [2.1.2. Process (b1-2): Irradiation with vacuum ultraviolet light] above.

[0174] The irradiation intensity of ultraviolet light can be appropriately adjusted to a range in which the desired inorganic encapsulation layer is obtained. To specify a range, the irradiation intensity is preferably 10 mW / cm² 2 Ideally, 100 mW / cm² 2 Ideally, 300 mW / cm² 2 Below, more preferably 200 mW / cm2 It is as follows. Among them, process (b2-2) is 100 mW / cm² 2 ~200 mW / cm 2 It is desirable to include at least one instance of ultraviolet irradiation at the maximum irradiation intensity. By irradiating with ultraviolet light at such an intensity, the modification reaction of the polysilazane compound can be carried out in a short time, or damage caused by ultraviolet light to the device part and the organic encapsulation layer can be suppressed.

[0175] The irradiation time of ultraviolet light can be appropriately adjusted to a range in which a desired inorganic encapsulation layer is obtained. Specifically, the irradiation time is preferably 0.1 seconds or more, more preferably 0.5 seconds or more, preferably 10 minutes or less, more preferably 3 minutes or less, and even more preferably 1 minute or less. By irradiating with ultraviolet light at such an irradiation time, the modification reaction of the polysilazane compound can be sufficiently carried out, thereby reducing variations in encapsulation ability or suppressing damage caused by ultraviolet light to the device part and the organic encapsulation layer.

[0176] It is preferable to perform the above-mentioned ultraviolet irradiation in an atmosphere with a low oxygen concentration. The specific oxygen concentration of the above atmosphere is preferably 500 ppm or more, more preferably 1000 ppm or more, preferably 10000 ppm or less, and more preferably 5000 ppm or less. The above unit "ppm" is based on mass. When the oxygen concentration of the atmosphere irradiated with ultraviolet light is within the above range, the modification reaction of the polysilazane compound can be effectively promoted, and the encapsulation ability of the obtained inorganic encapsulation layer can also be improved.

[0177] From the perspective of performing ultraviolet irradiation under an atmosphere of low oxygen concentration, it is preferable to perform ultraviolet irradiation of the intermediate layer under an inert gas atmosphere. The type of inert gas and the conditions for ultraviolet irradiation under an inert gas atmosphere may be the same as those described in [2.1.2. Process (b1-2): Vacuum Ultraviolet Irradiation] above.

[0178] [2.3. Process(c): Formation of silicone encapsulation layer]

[0179] In this embodiment, a process for forming a silicone encapsulation layer may be included. As a method for forming the silicone encapsulation layer, for example, a method of forming a layer containing a polysilazane compound and then irradiating with ultraviolet light may be used. Regarding the conditions for irradiating with ultraviolet light, for example, they may be the same as the conditions for irradiating with ultraviolet light for an intermediate layer described in [2.2.2. Process (b2-2): Irradiation with ultraviolet light for an intermediate layer] above.

[0180] [3. Variation Example]

[0181] The method for manufacturing a device structure according to the present embodiment has a process in which, in process (b), process (b1) and process (b2) are performed in this order, and the number of repetitions and process number of process (b1) and process (b2) are not limited and can be appropriately adjusted to suit the layer structure of the desired encapsulation layer.

[0182] Such a process may include, for example, a process (b) comprising a process (b3) for forming a first bag layer, a process (b4) for forming a second bag layer as an inorganic bag layer formed on the first bag layer, and a process (b5) for forming a third bag layer as an organic bag layer formed on the second bag layer, wherein the process (b4) and the process (b5) are performed alternately at least twice, and wherein the process (b4) is the process (b2) and the process (b5) is the process (b1).

[0183] When forming two or more organic bag layers and two or more inorganic bag layers, process (b1) and process (b2) may be performed the same number of times, process (b1) may be more than process (b2), and process (b1) may be less than process (b2).

[0184] In the above-described FIGS. 2 to 6, an example in which a silicone encapsulation layer is formed as the first encapsulation layer has been described, but for example, an organic encapsulation layer may be formed as the first encapsulation layer.

[0185] In addition, although not done in the city, for example, an organic encapsulation layer may be formed on the device part, and then an inorganic encapsulation layer may be formed to form a two-layer encapsulation layer.

[0186] For example, a method for manufacturing a device structure may include a process for forming any layer. Accordingly, a method for manufacturing a device structure may include a process for forming any layer between the device portion and the encapsulation layer. Additionally, a method for manufacturing a device structure may include a process for forming any layer covering the encapsulation portion. For a specific example, if the device structure is a display device having an organic electroluminescence device portion, a method for manufacturing the device structure may include a process for forming a layer of circular polarizers on the encapsulation layer by interposing an adhesive as necessary.

[0187] In the above-described manufacturing method, either the process (b1) for forming the organic encapsulation layer (210) and the process (b2) for forming the inorganic encapsulation layer (220) can be performed under an atmospheric pressure environment. Therefore, since large and complex manufacturing equipment is not required, the device structure (10) can be manufactured at a low cost. In addition, in particular, when the organic intermediate layer and the intermediate layer are formed by a coating method, the layer formation can be performed via a wet process, thereby suppressing the deterioration of the device part caused by particles such as plasma dust.

[0188] Examples

[0189] The present invention will be described in detail below by presenting examples. However, the present invention is not limited to the examples shown below, and may be implemented with arbitrary modifications within the scope of the claims of the present invention and their equivalents without departing from the scope of the claims and equivalents thereof.

[0190] In the following description, "%" and "parts" indicating amounts are based on weight unless otherwise noted. Additionally, the operations described below were performed under conditions of room temperature and pressure unless otherwise noted.

[0191] [Evaluation Method]

[0192] [Young's Modulus, Tensile Elongation, and Tanδ of Resins]

[0193] The Young's modulus and tensile elongation of the resin at 23°C were measured according to JIS K7113. The loss tangent tanδ (loss modulus / storage modulus) of the resin at temperatures between 40°C and 200°C was measured by making a film, cutting out a test specimen with a width of 10 mm × a length of 20 mm, and using a dynamic viscoelasticity measuring device DMS6100 manufactured by Hitachi High-Tech Science Co., Ltd.

[0194] [Evaluation of Bag Performance Under High Temperature and High Humidity Environments]

[0195] The above device structure was placed in a test environment at a temperature of 60°C and a humidity of 90% RH. After 0 hours, 24.5 hours, 138 hours, 210 hours, and 284.5 hours, the luminescent surface was observed under a microscope to check for the presence or absence of a discolored portion. In addition, shrinkage was measured after 0 hours, 24.5 hours, 138 hours, 210 hours, 284.5 hours, and 500 hours. Shrinkage is a value measured from the end of the initial luminescent portion to the length of the non-luminescent portion after a predetermined period of time.

[0196] [Preparation Example 1: Preparation of a modified product by silicon atom-containing polar group of a hydrogenated aromatic vinyl compound-conjugated diene block copolymer]

[0197] (P1-1. Preparation of hydrogenated block copolymers)

[0198] A hydride of a block copolymer (hydrogenated block copolymer) having a triblock structure in which polymer block [A] is bonded to both ends of polymer block [B] was prepared by using styrene as an aromatic vinyl compound and isoprene as a chain-type conjugated diene compound, in the following order.

[0199] 256 parts of dehydrated cyclohexane, 25.0 parts of dehydrated styrene, and 0.615 parts of n-dibutyl ether were added to a reactor equipped with a stirring device and sufficiently nitrogen-substituted interior. Polymerization was initiated by adding 1.35 parts of n-butyllithium (15% cyclohexane solution) while stirring at 60°C, and the reaction was carried out at 60°C for 60 minutes while further stirring. At this point, the polymerization conversion rate was 99.5% (the polymerization conversion rate was measured by gas chromatography. The same applies hereinafter).

[0200] Next, 50.0 parts of dehydrated isoprene were added, and stirring was continued for 30 minutes at the same temperature. At this point, the polymerization conversion rate was 99%.

[0201] After that, 25.0 parts of dehydrated styrene were added, and the mixture was stirred at the same temperature for 60 minutes. At this point, the polymerization conversion rate was approximately 100%.

[0202] Next, 0.5 parts of isopropyl alcohol were added to the reaction solution to stop the reaction, and a solution (i) containing a block copolymer was obtained.

[0203] The weight-average molecular weight (Mw) of the block copolymer in the obtained solution (i) was 44,900, and the molecular weight distribution (Mw / Mn) was 1.03 (measured as a polystyrene equivalent value by gel permeation chromatography using tetrahydrofuran as a solvent. The same applies hereinafter).

[0204] Next, the solution (i) was transferred to a pressure reactor equipped with a stirring device, and 4.0 parts of a silica-alumina supported nickel catalyst (E22U, nickel support 60%; manufactured by Nikki Chemical Industry Co., Ltd.) and 350 parts of dehydrated cyclohexane were added to the solution (i) as hydrogenation catalysts and mixed. The inside of the reactor was replaced with hydrogen gas, hydrogen was supplied while further stirring the solution, and the block copolymer was hydrogenated by carrying out a hydrogenation reaction at a temperature of 170°C and a pressure of 4.5 MPa for 6 hours to obtain a solution (iii) containing a hydride (ii) of the block copolymer. The weight average molecular weight (Mw) of the hydride (ii) in the solution (iii) was 45,100, and the molecular weight distribution (Mw / Mn) was 1.04.

[0205] After the hydrogenation reaction was completed, the solution (iii) was filtered to remove the hydrogenation catalyst. Then, 1.0 part of a xylene solution containing 0.1 part of the phosphorus-based antioxidant 6-[3-(3-t-butyl-4-hydroxy-5-methylphenyl)propoxy]-2,4,8,10-tetrakis-t-butyldibenzo[d,f][1.3.2]dioxaphosperpine (Sumitomo Chemical Co., Ltd. “Smilizer (registered trademark) GP”. Hereinafter referred to as “Antioxidant A”) was added to the filtered solution (iii) and dissolved to obtain solution (iv).

[0206] Next, the solution (iv) was filtered using a Zeta Plus (registered trademark) filter 30H (manufactured by Quno, pore size 0.5 μm to 1 μm) and then sequentially filtered using another metal fiber filter (pore size 0.4 μm, manufactured by Nichidai) to remove fine solids. From the filtered solution (iv), solvents such as cyclohexane, xylene, and other volatile components were removed using a cylindrical concentration dryer (product name "Contro", manufactured by Hitachi, Ltd.) at a temperature of 260°C and a pressure of 0.001 MPa or less. Then, the solids were extruded in a molten state into a strand from a die directly connected to the above concentration dryer, cooled, and cut with a pelletizer to obtain 85 parts of pellets (v) containing a block copolymer hydride and antioxidant A. The weight average molecular weight (Mw) of the block copolymer hydride (hydrogenated block copolymer) in the obtained pellet (v) was 45,000, and the molecular weight distribution (Mw / Mn) was 1.08. Also, 1 The hydrogenation rate measured by H-NMR was 99.9%.

[0207] (P1-2. Preparation of Silane Modified Hydrogenated Block Copolymers)

[0208] To 100 parts of the pellet (v) obtained in the above process (P1-1), 2.0 parts of vinyltrimethoxysilane and 0.2 parts of di-t-butyl peroxide were added to obtain a mixture. This mixture was kneaded using a twin-screw extruder at a barrel temperature of 210°C and a residence time of 80 to 90 seconds. The kneaded mixture was extruded and cut with a pelletizer to obtain a pellet (vi) of the silane-modified hydrogenated block copolymer. A film-like test specimen was prepared from this pellet (vi), and the glass transition temperature Tg was evaluated using the tanδ peak of a dynamic viscoelasticity measuring device, resulting in 124°C. In addition, the tanδ peak value of this pellet (vi) at temperatures between 40°C and 200°C was 1.3. The Young's modulus of this pellet (vi) at 23°C was 0.5 GPa, and the tensile elongation was 550%. In addition, the refractive index (n1) of this pellet (vi) measured by an Abbe refractometer was 1.50.

[0209] [Preparation Example 2: Preparation of a resin composition for forming an organic encapsulation layer]

[0210] (P2-1. Preparation of Hygroscopic Particle Dispersion)

[0211] 10 g of zeolite particles (refractive index 1.5) with a number average particle size of 50 nm of primary particles, 4 g of a dispersant having a basic adsorbent (hydroxyl group-containing carboxylic acid ester, trade name “DISPERBYK108”, manufactured by Big Chem Co.), and 46 g of cyclohexane were mixed and dispersed using a bead mill. By this operation, 17% zeolite dispersion 1 was prepared.

[0212] (P2-2. Preparation of Polymer Solution)

[0213] 28 g of the pellet (vi) obtained in Preparation Example 1 and 12 g of a plasticizer (a plasticizer containing an aliphatic hydrocarbon polymer, product name "Nisseki Polybutene LV-100", manufactured by Shin-Nippon Petroleum Co., Ltd., refractive index 1.50, number average molecular weight 500) were mixed and dissolved in 60 g of cyclohexane. By this operation, a polymer solution 1 with a solid content of 40% was prepared.

[0214] (P2-3. Preparation of Resin Composition)

[0215] 60 g of zeolite dispersion 1 obtained in the above process (P2-1) and 100 g of polymer solution 1 obtained in the above process (P2-2) were mixed to obtain resin solution 1 as a resin composition. The viscosity of the obtained resin solution 1 was measured. A tuning fork viscometer "SV-10" manufactured by A. and D. was used for the viscosity measurement. The measurement was performed by filling the container so that the liquid level of resin solution 1 was between the reference lines of the sample container, and inserting the vibrator into the resin solution up to the specified position. In addition, this measurement was performed under an environment of 25°C ± 2°C. As a result, the viscosity of resin solution 1 was 400 cP.

[0216] [Preparation Example 3: Preparation of a liquid composition of a silicone encapsulation layer (PDMS layer)]

[0217] A liquid composition for a PDMS layer was prepared by mixing a solution of X-34-4184-A, X-34-4184-B, and D5 KF-995 manufactured by Shin-Etsu Chemical in a weight ratio of X-34-4184-A:X-34-4184-B:D5 KF-995 = 1:1:16.

[0218] [Preparation Example 4: Preparation of a liquid composition for an inorganic encapsulation layer]

[0219] A liquid composition was prepared by mixing PHPS X-45-850 (20 wt% dibutyl ether solution) manufactured by Shin-Etsu Chemical Co., Ltd. and dibutyl ether (DBE) in a weight ratio of PHPS X-45-850:DBE = 1:1.

[0220] [Preparation Example 5: Preparation of a multilayer having an organic electroluminescence element]

[0221] A glass substrate with dimensions of 40 mm in length × 40 mm in width was prepared. On the glass substrate, a transparent electrode layer with a thickness of 100 nm, a hole transport layer with a thickness of 10 nm, a yellow light-emitting layer with a thickness of 20 nm, an electron transport layer with a thickness of 15 nm, an electron injection layer with a thickness of 1 nm, and a reflective electrode layer with a thickness of 100 nm were formed in this order.

[0222] From the hole transport layer to the electron transport layer, the entire structure was formed using organic materials. The materials forming each layer from the transparent electrode layer to the reflective electrode layer were as follows.

[0223] · Transparent electrode layer; Indium tin oxide (ITO)

[0224] · Hole transport layer; 4,4'-bis[N-(naphthyl)-N-phenylamino]biphenyl(α-NPD)

[0225] · Yellow light-emitting layer; α-NPD with 1.5 wt% rubrene added

[0226] · Electron transport layer; phenanthroline derivative (BCP)

[0227] · Electron injection layer; Lithium fluoride (LiF)

[0228] · Reflective electrode layer; Al

[0229] The transparent electrode layer was formed using a reactive sputtering method with an ITO target.

[0230] In addition, the formation of the hole transport layer to the reflective electrode layer was carried out by installing a substrate having already formed a transparent electrode layer in a vacuum deposition apparatus and sequentially depositing the materials from the hole transport layer to the reflective electrode layer by a resistance heating method.

[0231] By the above operation, a multilayer structure was obtained having a glass substrate; and an organic electroluminescence element part having a transparent electrode layer, a hole transport layer, a yellow light-emitting layer, an electron transport layer, an electron injection layer, and a reflective electrode layer in this order.

[0232] [Example]

[0233] To cover the organic electroluminescence element portion of the multilayer fabricated in Preparation Example 5, the liquid composition for the PDMS layer obtained in Preparation Example 3 was coated by a spin coat method (conditions: drop amount 1 mL, rotation speed 6000 rpm, 30 seconds) and dried, after which UV (365 nm) was applied at 12 mW / cm² 2 The PDMS layer was cured by irradiation for 200 seconds. Subsequently, VUV (172 nm) was applied to the PDMS layer at 55 mW / cm² under an N2 atmosphere. 2 It was irradiated for 130 seconds. By the above sequence, a PDMS layer (first encapsulation layer) with a thickness of approximately 170 nm was obtained.

[0234] Next, the liquid composition for the inorganic encapsulant layer of Preparation Example 4 is coated by the spin coat method (conditions: drop amount 1 mL, rotation speed 6000 rpm, 30 seconds) and dried, and then VUV (172 nm) is applied at 55 mW / cm² under an N2 atmosphere. 2 It was irradiated for 220 seconds. By the above sequence, an inorganic encapsulation layer (second encapsulation layer) with a thickness of 130 nm was obtained. This process corresponds to process (b2).

[0235] Next, the resin composition obtained in Preparation Example 2 was coated by a spin coat method (conditions: drop volume 1 mL, rotation speed 6000 rpm, 60 seconds) and dried to form an organic intermediate layer. Next, VUV (172 nm) was applied to the organic intermediate layer at 55 mW / cm² under an N2 atmosphere. 2 It was irradiated for 220 seconds. Afterwards, oxygen was introduced until the O2 concentration in the system reached 5%, and VUV (172 nm) was applied at 55 mW / cm² under a mixed N2 and O2 atmosphere. 2 It was irradiated for 220 seconds. By the following sequence, an organic encapsulation layer (third encapsulation layer) with a thickness of 100 nm was obtained. This process corresponds to process (b1).

[0236] In addition, by repeating process (b2) and process (b1), a sealing layer having a 7-layer structure as shown in FIG. 1 was fabricated. A device structure was obtained by the above sequence.

[0237] In addition, the resin composition obtained in Preparation Example 2 is coated onto a silicon substrate to form an organic encapsulation layer identical to the third encapsulation layer, and VUV (172 nm) is applied at an illuminance of 30 mW / cm² under an N2 atmosphere, in an environment of 23°C to 25°C and 50% to 60% humidity. 2 After irradiating for 3 minutes, a sample was obtained. After measuring the thickness T1 of the organic encapsulation layer of the obtained sample, it was immersed in dibutyl ether for 60 seconds and then air-dried. After air-drying, the thickness T2 of the organic encapsulation layer of the sample was measured. From the measured values ​​of T1 and T2, the residual film rate of the organic encapsulation layer for the dissolution test in dibutyl ether was calculated to be 97%.

[0238] [Comparative Example]

[0239] Similar to the example, a PDMS layer and an inorganic encapsulation layer were fabricated on the organic electroluminescence device portion of the multilayer structure. Next, a third PDMS layer was formed on the second inorganic encapsulation layer by repeating the same sequence as the first PDMS layer. Subsequently, the inorganic encapsulation layer and the PDMS layer were further alternately stacked in pairs by following the same sequence as the second inorganic encapsulation layer and the first PDMS layer, thereby fabricating an encapsulation layer having a seven-layer structure. A device structure was obtained by the above sequence.

[0240] [result]

[0241] Figure 7 shows a photograph of the luminescent surface during the evaluation of bag performance under a high temperature and high humidity environment, and Figure 8 shows a graph showing the numerical change in shrinkage over time. As shown in Figures 7 and 8, it was confirmed that the embodiment including the organic bag layer and the inorganic bag layer according to the present embodiment exhibits good bag performance, as no discoloration was observed on the luminescent surface even after 284.5 hours, and the change in shrinkage was small. On the other hand, in the comparative example, it was confirmed that the discoloration point gradually increased starting from 138 hours, and the shrinkage also increased.

[0242] [Reference Example]

[0243] The resin composition obtained in Preparation Example 2 was applied onto a silicon substrate and heated at 100°C for 1 minute to form an organic layer with a thickness of 120 nm. Under a nitrogen atmosphere, VUV (172 nm) was applied at an illuminance of 30 mW / cm² 2 As a result of irradiating the organic layer and measuring the FT-IR spectra before and after irradiation, 2925 cm⁻¹ -1 It was confirmed that the peak intensity decreased before and after VUV irradiation. Furthermore, by adjusting the irradiation time and investigating the correlation between the ratio of I2 to I1 (where the peak intensity before VUV irradiation is I1 and the peak intensity after irradiation is I2) and the residual film rate in the dibutyl ether dissolution test, it was confirmed that organic layers with an I2 / I1 ratio of 50% or less exhibited a residual film rate of 90% or higher. In the FT-IR spectrum, at 2925 cm⁻¹ -1 The peak in is a peak originating from CH stretching vibration.

[0244] In the reference example, the VUV irradiation time and residual film rate were as follows.

[0245] · Irradiation time 1 minute, residue rate 80%

[0246] · Irradiation time 3 minutes, residue rate 97%

[0247] · Irradiation time 5 minutes, film retention rate 100% Explanation of the symbols

[0248] 10 Device Structure 100 duplexes 110 entry 120 component section 121 First electrode layer 122 light-emitting layer 123 Second electrode layer 200 bag layers 201 1st bag layer 202 Second bag layer 203 Third bag layer 210 organic bag layer 220 Weapon Bag Layer 230 silicone encapsulation layer

Claims

Claim 1 A device structure comprising a substrate and a multilayer having a device portion formed on the substrate, and a sealing layer encapsulating the device portion, wherein the sealing layer has a structure in which an organic sealing layer and an inorganic sealing layer are stacked in this order with respect to the device portion, wherein the inorganic sealing layer comprises silicon nitride and the organic sealing layer comprises a thermoplastic elastomer, and furthermore, in a dissolution test for dibutyl ether, the residual film rate of the organic sealing layer is 90% or more, and the thermoplastic elastomer is one or more selected from the group consisting of a hydrogenated aromatic vinyl compound-conjugated diene block copolymer and a modified product of a hydrogenated aromatic vinyl compound-conjugated diene block copolymer containing silicon atoms. Claim 2 A device structure according to claim 1, wherein the encapsulation layer comprises a first encapsulation layer formed on the element portion, and two or more second encapsulation layers and two or more third encapsulation layers formed on the first encapsulation layer, and the second encapsulation layer and the third encapsulation layer are alternately stacked, wherein the second encapsulation layer is the inorganic encapsulation layer and the third encapsulation layer is the organic encapsulation layer. Claim 3 A device structure according to paragraph 2, wherein the first encapsulation layer is the organic encapsulation layer or a silicone encapsulation layer comprising silicone. Claim 4 A device structure according to claim 1 or 2, wherein the hydrogenated aromatic vinyl compound-conjugated diene block copolymer has a structure in which both non-aromatic carbon-carbon unsaturated bonds and aromatic carbon-carbon unsaturated bonds are hydrogenated. Claim 5 A device structure according to claim 1 or 2, wherein the organic encapsulation layer comprises one or more types selected from the group consisting of hygroscopic particles and ultraviolet absorbers. Claim 6 A device structure according to claim 1 or 2, wherein the thickness of each constituent layer included in the encapsulation layer is 300 nm or less. Claim 7 A device structure according to claim 1 or 2, wherein the element part is an organic electroluminescence element part. Claim 8 A method for manufacturing a device structure comprising a process (a) for preparing a multilayer having a substrate and a device portion formed on the substrate, and a process (b) for forming an encapsulation layer that encapsulates the device portion, wherein the process (b) for forming the encapsulation layer comprises a process (b1) for forming an organic encapsulation layer and a process (b2) for forming an inorganic encapsulation layer after the process (b1), wherein the process (b1) comprises a process (b1-1) for forming an organic intermediate layer comprising a thermoplastic elastomer and a process (b1-2) for obtaining the organic encapsulation layer by irradiating the organic intermediate layer with vacuum ultraviolet light, and wherein the process (b2) comprises a process (b2-1) for forming an intermediate layer using a liquid composition comprising a polysilazane compound and a solvent, and a process (b2-2) for obtaining an inorganic encapsulation layer comprising silicon nitride by irradiating the intermediate layer with ultraviolet light, wherein the thermoplastic elastomer comprises a hydrogenated aromatic vinyl compound-conjugated diene block copolymer and a hydrogenated aromatic vinyl compound-conjugated diene block A method for manufacturing a device structure comprising one or more types selected from the group consisting of modified materials containing silicon atoms of polar groups of copolymers. Claim 9 A method for manufacturing a device structure according to claim 8, wherein the liquid phase composition of the above process (b) comprises dibutyl ether as the solvent. Claim 10 A method for manufacturing a device structure according to claim 8 or 9, wherein the process (b1-2) comprises a process (b1-2-1) of irradiating vacuum ultraviolet rays under an inert gas atmosphere onto the organic intermediate layer, and a process (b1-2-2) of irradiating vacuum ultraviolet rays under a mixed atmosphere of inert gas and oxygen onto the organic intermediate layer after the process (b1-2-1). Claim 11 A method for manufacturing a device structure according to claim 8 or 9, wherein the process (b) comprises a process (b3) for forming a first encapsulation layer, a process (b4) for forming a second encapsulation layer as the inorganic encapsulation layer formed on the first encapsulation layer, and a process (b5) for forming a third encapsulation layer as the organic encapsulation layer formed on the second encapsulation layer, wherein the process (b4) and the process (b5) are performed alternately at least twice, wherein the process (b4) is the process (b2) and the process (b5) is the process (b1). Claim 12 A method for manufacturing a device structure, wherein, in claim 11, the process (b3) is the process (b1) and is a process for forming the first encapsulation layer as the organic encapsulation layer. Claim 13 delete

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