Optical semiconductor element sealing sheet and optical semiconductor device

Abstract

To provide An optical semiconductor element sealing sheet that excels in anti-reflection properties, optical semiconductor element sealing properties, and workability during tiling, and is less likely to cause damage to the sheet when separating adjacent optical semiconductor devices.SOLUTION: An optical semiconductor element sealing sheet 1 is a sheet for sealing one or more optical semiconductor elements 6 arranged on a substrate 5. The optical semiconductor element sealing sheet 1 comprises a sealing resin layer 2 that includes at least a colored adhesive layer 21. The colored adhesive layer 2 contains a coloring agent, has thermosetting properties, and is a layer that comes into contact with the optical semiconductor element 6 when the optical semiconductor element 6 is sealed with the optical semiconductor element sealing sheet 1.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a sheet for encapsulating an optoelectronic device and an optoelectronic device. More specifically, the present invention relates to a sheet suitable for use in encapsulating an optoelectronic device, and an optoelectronic device having a structure in which the sheet encapsulates the optoelectronic device.

Background Art

[0002] In a self-emitting display device such as a mini / micro light emitting diode display (Mini / Micro Light Emitting Diode Display), a plurality of LEDs are arranged on a substrate, and a structure in which the plurality of LEDs are encapsulated with an encapsulating resin is known. As a method of encapsulating the plurality of LEDs collectively using the encapsulating resin, a method is known in which a liquid resin is poured into a region where the plurality of LEDs are arranged, the plurality of LEDs are buried, and then the liquid resin is cured by heat or ultraviolet irradiation.

[0003] However, in the method of encapsulating an optoelectronic device such as an LED using a liquid resin, there is a problem of poor handleability, such as dripping when applying the liquid resin and the liquid resin adhering to an unintended area. On the other hand, instead of using a liquid resin, by adopting the form of an encapsulating sheet provided with an encapsulating layer for encapsulating the optoelectronic device, it is possible to easily encapsulate the optoelectronic device in a simple process and in a short time.

[0004] In an image display device including a self-emitting display device, wirings of metal oxides such as metal and ITO (metal wirings) are arranged on the substrate of the display panel. Such a display device has a problem that, for example, at the time of turning off the light, light is reflected by the metal wiring or the like, resulting in poor appearance of the screen and inferior design. For this reason, a technique using an antireflection layer for preventing reflection by the metal wiring is adopted as an encapsulating material for encapsulating the optoelectronic device.

[0005] By the way, with the improvement of image quality such as 4K and 8K, the demand for larger-screen image display devices is increasing. In addition, the use of larger-screen image display devices for signage such as advertising displays and bulletin boards in outdoor areas and public facilities is also progressing. However, when manufacturing a larger-screen image display device, there is a problem that the yield decreases and the manufacturing cost increases. In order to manufacture a larger-screen image display device at a lower cost, a tiling display in which a plurality of optoelectronic devices such as image display devices are arranged in a tile shape is being considered.

[0006] Patent Document 1 discloses a tiling display device in which a plurality of display devices each including a light-emitting diode substrate with a sealing member that seals a light-emitting diode with a sealing member containing a thermoplastic resin are arranged in parallel.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0008] Here, it is important that the sealing sheet has excellent sealing properties for the optoelectronic element and excellent adhesion to the optoelectronic element and the substrate provided with the optoelectronic element in order to sufficiently seal the optoelectronic element. However, when an adhesive layer using a thermoplastic resin is used as the sealing member as described in Patent Document 1, the adhesiveness is high, and when a plurality of optoelectronic devices are arranged in a tile shape, that is, during tiling, the optoelectronic devices are difficult to separate from the hand or jig, resulting in poor workability.

[0009] In addition, when misalignment or the like occurs between adjacent optical semiconductor devices during tiling or when rearrangement is necessary, position correction is performed. To perform position correction, it is necessary to temporarily separate adjacent optical semiconductor devices. However, when separating them, the sealing sheet in one optical semiconductor device and the sealing sheet in the other adjacent optical semiconductor device may adhere to each other and pull, and there may be a defect in the sealing sheet in one optical semiconductor device. A sealing sheet having excellent adhesion to an optical semiconductor element or a substrate is particularly likely to have such a problem.

[0010] The present invention has been conceived under such circumstances, and its object is to provide an optical semiconductor element sealing sheet that is excellent in antireflection properties, sealing properties of an optical semiconductor element, and workability during tiling, and in which sheet loss hardly occurs when adjacent optical semiconductor devices are separated from each other.

Means for Solving the Problems

[0011] As a result of intensive studies to achieve the above object, the present inventors have found that according to a specific sealing sheet, it is excellent in antireflection properties, sealing properties of an optical semiconductor element, and workability during tiling, and sheet loss hardly occurs when adjacent optical semiconductor devices are separated from each other. The present invention has been completed based on these findings.

[0012] That is, the present invention is a sheet for sealing one or more optical semiconductor elements disposed on a substrate, The sheet includes a sealing resin layer including at least a thermosetting colored adhesive layer, The colored adhesive layer contains a colorant and is a layer that contacts the optical semiconductor element when the optical semiconductor element is sealed with the sheet, and is an optical semiconductor element sealing sheet.

[0013] The thickness of the colored adhesive layer is preferably 5 to 150 μm.

[0014] The resin layer for sealing may include an uncolored layer located on the side opposite to the side for sealing the optical semiconductor element with respect to the colored adhesive layer.

[0015] The elastic modulus G' of the colored adhesive layer at 130 °C before curing is preferably 0.5 to 10 kPa.

[0016] The elastic modulus E' of the colored adhesive layer at room temperature before curing is preferably 500 to 4000 MPa.

[0017] The elastic modulus E' of the colored adhesive layer at room temperature after curing is preferably 500 to 4000 MPa.

[0018] The light transmittance of the colored adhesive layer at a wavelength of 600 nm after curing is preferably 0 to 80%.

[0019] In the state where the optical semiconductor element is sealed, the distance from the optical semiconductor element to the colored adhesive layer of the sheet for sealing the optical semiconductor element is preferably 0 to 20 μm.

[0020] The sheet for sealing the optical semiconductor element may be provided with a layer having antiglare properties and / or antireflection properties on the surface on the side opposite to the side in contact with the optical semiconductor element with respect to the resin layer for sealing.

[0021] Further, the present invention provides an optical semiconductor device including a substrate, an optical semiconductor element disposed on the substrate, and the sheet for sealing the optical semiconductor element or a cured product thereof for sealing the optical semiconductor element.

Effects of the Invention

[0022] According to the sheet for encapsulating an optical semiconductor element of the present invention, it is excellent in antireflection property, encapsulation property of the optical semiconductor element, and workability during tiling, and it is difficult for the sheet to be damaged when separating adjacent optical semiconductor devices. Therefore, after tiling the optical semiconductor devices, when misalignment or the like occurs between adjacent optical semiconductor devices or when rearrangement is required, the position can be easily corrected without problems, the loss of the optical semiconductor devices can be reduced, and a display with good appearance can be manufactured economically and excellently.

Brief Description of the Drawings

[0023]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Embodiments for Carrying Out the Invention

[0024] [Sheet for Encapsulating Optical Semiconductor Element] The sheet for encapsulating an optical semiconductor device of the present invention includes at least an encapsulating resin layer containing a colored adhesive layer. In this specification, the sheet for encapsulating an optical semiconductor device refers to a sheet for encapsulating one or more optical semiconductor devices disposed on a substrate with an encapsulating resin layer. Further, in this specification, "encapsulating an optical semiconductor device" means embedding at least a part of the optical semiconductor device in the encapsulating resin layer or following and covering it with the above encapsulating resin layer. The above encapsulating resin layer has flexibility such that at least a part of the optical semiconductor device can be embedded or followed and covered by the above encapsulating resin layer.

[0025] <Encapsulating resin layer> The above encapsulating resin layer includes at least the above colored adhesive layer. The above encapsulating resin layer may include other layers other than the above colored adhesive layer. Examples of the above other layers include a non-colored layer and a colored adhesive layer. The above encapsulating resin layer may include a non-colored layer located on the side opposite to the side for encapsulating the optical semiconductor device with respect to the above colored adhesive layer. Each layer (such as the colored adhesive layer and the non-colored layer) constituting the above encapsulating resin layer may be a single layer in the above encapsulating resin layer, or may be a multi-layer having the same or different compositions. When a multi-layer of a colored adhesive layer or a non-colored layer is included, the above multi-layers may be laminated in contact with each other, or may be laminated separately (for example, two colored adhesive layers are laminated via one non-colored layer).

[0026] In the above-mentioned resin layer for encapsulation, the layer that contacts the optical semiconductor element when encapsulating the optical semiconductor element (that is, the layer closest to the optical semiconductor element side in the above-mentioned resin layer for encapsulation) is a thermosetting colored adhesive layer. When the layer in contact with the optical semiconductor element is a thermosetting colored adhesive layer, it has excellent workability before thermosetting, and exhibits adhesiveness to the optical semiconductor element and the substrate after thermosetting. Also, the above-mentioned non-colored layer is preferably a thermosetting adhesive layer (thermosetting adhesive layer). It is preferable that all the colored layers and non-colored layers in the above-mentioned resin layer for encapsulation are thermosetting adhesive layers. In this specification, the "adhesive layer" is different from a pressure-sensitive adhesive layer, and does not have tackiness or adhesiveness on the surface, or has extremely little of them, and has curability and adheres to the adherend by curing.

[0027] (Colored adhesive layer) The colored adhesive layer in the above-mentioned resin layer for encapsulation is a layer for the purpose of preventing reflection of light by metal wiring or the like provided on a substrate in an image display device. The "adhesive layer" is different from a pressure-sensitive adhesive layer, and does not have tackiness or adhesiveness on the surface, or has extremely little of them, and has curability and adheres to the adherend by curing. The above-mentioned colored adhesive layer has thermosetting properties and exhibits adhesiveness to the optical semiconductor element and the substrate by thermosetting. The above-mentioned colored adhesive layer is a layer located at a position in contact with the optical semiconductor element when the optical semiconductor element is encapsulated with the above-mentioned optical semiconductor element encapsulating sheet.

[0028] The above-mentioned colored adhesive layer contains at least a colorant. The colorant may be a dye or a pigment as long as it is soluble or dispersible in the above-mentioned colored adhesive layer. Dyes are preferred because low haze can be achieved even with a small amount of addition, and they do not have sedimentation properties like pigments and are easily uniformly distributed. Also, pigments are preferred because high color expressibility can be achieved even with a small amount of addition. When using a pigment as the colorant, it is preferably one with low conductivity or no conductivity. The above-mentioned colorant may be used alone or in combination of two or more.

[0029] As the above coloring agent, a black coloring agent is preferred. As the above black coloring agent, known or commonly used coloring agents (pigments, dyes, etc.) for exhibiting black can be used. For example, carbon black (furnace black, channel black, acetylene black, thermal black, lamp black, pine soot, etc.), graphite, copper oxide, manganese dioxide, aniline black, perylene black, titanium black, cyanine black, activated carbon, ferrite (non-magnetic ferrite, magnetic ferrite, etc.), magnetite, chromium oxide, iron oxide, molybdenum disulfide, chromium complex, anthraquinone-based coloring agent, zirconium nitride, etc. can be mentioned. Further, a coloring agent that functions as a black coloring agent by combining coloring agents that exhibit colors other than black may also be used.

[0030] When the above coloring adhesive layer is a radiation-curable resin layer, the above coloring agent preferably absorbs visible light and has permeability to light having a wavelength at which the above radiation-curable resin layer can be cured.

[0031] From the viewpoint of imparting an appropriate antireflection ability to the image display device, the content ratio of the coloring agent in the above coloring adhesive layer is preferably 0.2% by mass or more, more preferably 0.4% by mass or more, based on the total amount (100% by mass) of the coloring adhesive layer. Further, the content ratio of the above coloring agent is, for example, 10% by mass or less, preferably 5% by mass or less, more preferably 3% by mass or less. The above content ratio may be appropriately set according to the type of the coloring agent, the color tone and light transmittance of the image display device, etc. The coloring agent may be added to the composition as a solution or dispersion dissolved or dispersed in an appropriate solvent.

[0032] Examples of the resin constituting the colored adhesive layer include known or commonly used resins, such as acrylic resins, urethane acrylate resins, urethane resins, rubber resins, epoxy resins, epoxy acrylate resins, oxetane resins, silicone resins, silicone acrylic resins, polyester resins, polyether resins (such as polyvinyl ether), polyamide resins, fluorine resins, vinyl acetate / vinyl chloride copolymers, modified polyolefins, etc. Only one type of the above resin may be used, or two or more types may be used. Among them, acrylic resins are preferred.

[0033] The above acrylic resin is a resin containing a structural unit derived from an acrylic monomer (a monomer component having a (meth)acryloyl group or a structure convertible thereto) as a structural unit of the resin (polymer). Only one type of the above acrylic resin may be used, or two or more types may be used.

[0034] The above acrylic resin preferably contains the largest mass ratio of the structural unit derived from (meth)acrylate. In this specification, "(meth)acrylic" represents "acrylic" and / or "methacrylic" (either one or both of "acrylic" and "methacrylic"), and the same applies to others.

[0035] From the viewpoint of having thermosetting properties, the colored adhesive layer preferably contains a thermosetting resin. As the above thermosetting resin, known or commonly used thermosetting resins can be used, for example, resins having thermosetting functional groups can be mentioned. Among them, as the above thermosetting resin, an acrylic resin having a thermosetting functional group (thermosetting functional group-containing acrylic resin) is preferred.

[0036] Examples of the above-mentioned thermosetting functional groups include epoxy group-containing groups such as glycidyl groups, carboxy groups, hydroxy groups, isocyanate groups, aziridyl groups, and the like. Among them, epoxy group-containing groups are preferred, and glycidyl groups are more preferred. That is, as the acrylic resin having a thermosetting functional group, a glycidyl group-containing acrylic resin is particularly preferred. The above-mentioned thermosetting functional group may have only one kind or two or more kinds.

[0037] The above-mentioned thermosetting functional group-containing acrylic resin preferably contains a structural unit derived from a monomer having a thermosetting functional group, and more preferably contains a structural unit derived from an acrylic monomer having a thermosetting functional group (thermosetting functional group-containing acrylic monomer). Examples of the monomer having the above-mentioned thermosetting functional group include epoxy group-containing (meth)acrylic acid esters such as glycidyl group-containing (meth)acrylic acid esters, carboxy group-containing monomers, acid anhydride group-containing monomers, and hydroxy group-containing (meth)acrylic acid esters.

[0038] Examples of the above-mentioned glycidyl group-containing (meth)acrylic acid ester include glycidyl (meth)acrylate, methyl glycidyl (meth)acrylate, and the like.

[0039] Examples of the above-mentioned carboxy group-containing monomer include acrylic acid, methacrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, itaconic acid, maleic acid, fumaric acid, crotonic acid, and the like. Examples of the above-mentioned acid anhydride group-containing monomer include maleic anhydride, itaconic anhydride, and the like.

[0040] Examples of the above hydroxy group-containing (meth)acrylic acid ester include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, 12-hydroxylauryl (meth)acrylate, (4-hydroxymethylcyclohexyl)methyl (meth)acrylate, and the like.

[0041] Among the above thermosetting functional group-containing acrylic monomers, epoxy group-containing (meth)acrylic acid esters are preferred, and glycidyl group-containing (meth)acrylic acid esters are more preferred. When the above acrylic resin contains a structural unit derived from an epoxy group-containing (meth)acrylic acid ester, the epoxy group acts as a thermosetting functional group, and even when no curing agent is blended, the reaction of the epoxy group proceeds by thermosetting, and the above colored adhesive layer is cured. Therefore, the above colored adhesive layer has appropriate flexibility after thermosetting and is excellent in the sealing property of the optical semiconductor element.

[0042] The content ratio of the structural unit derived from the above epoxy group-containing (meth)acrylic acid ester is preferably 5 to 50% by mass, more preferably 6 to 45% by mass, based on the total amount (100% by mass) of all the structural units of the acrylic resin in the above colored adhesive layer. When the above content ratio is within the above range, the above colored adhesive layer has appropriate flexibility after thermosetting and is excellent in the sealing property of the optical semiconductor element.

[0043] The above thermosetting functional group-containing acrylic resin may contain a structural unit derived from other monomers other than the above thermosetting functional group-containing monomers. Examples of the above other monomers include other (meth)acrylic acid esters other than the above thermosetting functional group-containing acrylic monomers. Only one kind of the above other monomers may be used, or two or more kinds may be used.

[0044] Examples of the above-mentioned other (meth)acrylic acid esters include hydrocarbon group-containing (meth)acrylic acid esters which may have an alkoxy group. Examples of the hydrocarbon group-containing (meth)acrylic acid esters in the hydrocarbon group-containing (meth)acrylic acid esters which may have an alkoxy group include (meth)acrylic acid alkyl esters having a linear or branched aliphatic hydrocarbon group, (meth)acrylic acid esters having an alicyclic hydrocarbon group such as (meth)acrylic acid cycloalkyl esters, and (meth)acrylic acid esters having an aromatic hydrocarbon group such as (meth)acrylic acid aryl esters. The hydrocarbon group-containing (meth)acrylic acid esters which may have an alkoxy group may be used alone or in combination of two or more.

[0045] Examples of the above-mentioned (meth)acrylic acid alkyl esters include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, s-butyl (meth)acrylate, t-butyl (meth)acrylate, pentyl (meth)acrylate, isopentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, nonyl (meth)acrylate, isononyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate (lauryl (meth)acrylate), tridecyl (meth)acrylate, tetradecyl (meth)acrylate, pentadecyl (meth)acrylate, hexadecyl (meth)acrylate, heptadecyl (meth)acrylate, octadecyl (meth)acrylate, nonadecyl (meth)acrylate, eicosyl (meth)acrylate, etc.

[0046] Among the above (meth)acrylic acid alkyl esters, those having a linear or branched aliphatic hydrocarbon group with 1 to 20 carbon atoms (preferably 1 to 14, more preferably 2 to 10, and even more preferably 2 to 8) are preferred. When the number of carbon atoms is within the above range, it is easier to make the flexibility of the above thermosetting group-containing acrylic resin more appropriate during thermosetting, and the embedding property is further improved.

[0047] Examples of the (meth)acrylic acid ester having the above alicyclic hydrocarbon group include (meth)acrylic acid esters having a monocyclic aliphatic hydrocarbon ring such as cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate, cycloheptyl (meth)acrylate, and cyclooctyl (meth)acrylate; (meth)acrylic acid esters having a bicyclic aliphatic hydrocarbon ring such as isobornyl (meth)acrylate; (meth)acrylic acid esters having a tricyclic or higher aliphatic hydrocarbon ring such as dicyclopentanyl (meth)acrylate, dicyclopentanyloxyethyl (meth)acrylate, tricyclopentanyl (meth)acrylate, 1-adamantyl (meth)acrylate, 2-methyl-2-adamantyl (meth)acrylate, and 2-ethyl-2-adamantyl (meth)acrylate.

[0048] Examples of the (meth)acrylic acid ester having the above aromatic hydrocarbon group include phenyl (meth)acrylate and benzyl (meth)acrylate.

[0049] Examples of the hydrocarbon group-containing (meth)acrylic acid ester having an alkoxy group include those in which one or more hydrogen atoms in the hydrocarbon group of the above hydrocarbon group-containing (meth)acrylic acid ester are substituted with an alkoxy group, such as 2-methoxymethyl ester, 2-methoxyethyl ester, and 2-methoxybutyl ester of (meth)acrylic acid.

[0050] Examples of the above-mentioned other monomer components further include polar group-containing monomers such as sulfonic acid group-containing monomers, phosphoric acid group-containing monomers, and nitrogen atom-containing monomers. Examples of the sulfonic acid group-containing monomers include styrene sulfonic acid, allyl sulfonic acid, 2-(meth)acrylamide-2-methylpropane sulfonic acid, (meth)acrylamide propane sulfonic acid, sulfopropyl (meth)acrylate, (meth)acryloyloxy naphthalene sulfonic acid, and the like. Examples of the phosphoric acid group-containing monomers include 2-hydroxyethyl acryloyl phosphate and the like. Examples of the nitrogen atom-containing monomers include morpholino group-containing monomers such as (meth)acryloyl morpholine, cyano group-containing monomers such as (meth)acrylonitrile, amide group-containing monomers such as (meth)acrylamide, and the like.

[0051] In order to form a crosslinked structure in the polymer skeleton of the above-mentioned thermosetting functional group-containing acrylic resin, it may contain a structural unit derived from a polyfunctional (meth)acrylate copolymerizable with the monomer components constituting the acrylic resin. Examples of the polyfunctional (meth)acrylate include hexanediol di(meth)acrylate, (poly)ethylene glycol di(meth)acrylate, (poly)propylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, pentaerythritol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and the like. Only one kind of the polyfunctional (meth)acrylate may be used, or two or more kinds may be used.

[0052] The above acrylic resin containing a thermosetting functional group is obtained by polymerizing the above various monomer components. The polymerization method is not particularly limited, and examples thereof include a solution polymerization method, an emulsion polymerization method, a bulk polymerization method, and a polymerization method by irradiation with active energy rays (active energy ray polymerization method). Further, the obtained acrylic resin may be any of a random copolymer, a block copolymer, a graft copolymer, and the like.

[0053] From the viewpoint of having a certain degree of hardness after curing of the colored adhesive layer and reducing the adhesion between the side surfaces of the optical semiconductor device, the weight average molecular weight of the above epoxy group-containing acrylic resin is preferably 2,000 to 400,000, more preferably 30,000 to 300,000. When the weight average molecular weight is within the above range, the embedding property of the optical semiconductor element is excellent. The weight average molecular weight refers to a value measured by gel permeation chromatography (GPC) and calculated in terms of polystyrene.

[0054] The content ratio of the above epoxy group-containing acrylic resin is preferably 40% by mass or more (for example, 40 to 100% by mass), more preferably 50% by mass or more, and still more preferably 60% by mass or more, based on the total amount of the resin (100% by mass) in the colored adhesive layer. When the content ratio is 40% by mass or more, the embedding property of the optical semiconductor element is excellent.

[0055] The above colored adhesive layer preferably contains a component having a functional group (second functional group) capable of reacting with heat with the thermosetting functional group (first functional group) in the above acrylic resin containing a thermosetting functional group. The second functional group is also a thermosetting functional group. In this case, the curing of the colored adhesive layer is further promoted by the reaction between the first functional group and the second functional group during heating of the colored adhesive layer.

[0056] The component having the second functional group may be a thermosetting functional group-containing acrylic resin having the first functional group, or a thermosetting functional group-containing acrylic resin other than the thermosetting functional group-containing acrylic resin having the first functional group, or another component having the second functional group. Only one kind of the component having the second functional group may be used, or two or more kinds may be used.

[0057] Examples of the combination of the first functional group and the second functional group include a carboxy group and an epoxy group, an epoxy group and a carboxy group, a carboxy group and an aziridyl group, an aziridyl group and a carboxy group, a hydroxy group and an isocyanate group, an isocyanate group and a hydroxy group, and the like. Only one kind of the combination may be used, or two or more kinds may be used.

[0058] When the epoxy group-containing acrylic resin is included, it is preferable that the colored adhesive layer includes, as the component having the second functional group, a component having a functional group reactive with the epoxy group. Examples of the functional group reactive with the epoxy group include a carboxy group, an aziridyl group, a hydroxy group, and the like. Among them, a carboxy group and a hydroxy group are preferable. From the viewpoint of high acidity and excellent reactivity with the epoxy group, a silanol group is preferable as the hydroxy group.

[0059] The component having the carboxy group is preferably the resin, more preferably a carboxy group-containing acrylic resin. When the carboxy group-containing acrylic resin is contained, the reaction between the epoxy group and the carboxy group in the epoxy group-containing acrylic resin proceeds more easily even when no curing agent is blended, and the sealing property of the optical semiconductor element is more excellent. In addition, the surface scratch resistance is even more excellent.

[0060] The above carboxyl group-containing acrylic resin preferably contains a structural unit derived from a carboxyl group-containing monomer, and more preferably contains a structural unit derived from a carboxyl group-containing acrylic monomer. Examples of the above carboxyl group-containing monomer include acrylic acid, methacrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, itaconic acid, maleic acid, fumaric acid, crotonic acid, and the like.

[0061] The content ratio of the structural unit derived from the above carboxyl group-containing acrylic monomer is preferably 1 to 50% by mass, more preferably 10 to 40% by mass, based on the total amount (100% by mass) of all the structural units of the above carboxyl group-containing acrylic resin. When the above content ratio is within the above range, the above coloring adhesive layer has appropriate flexibility after thermosetting and is excellent in the sealing property of the optical semiconductor element.

[0062] The above carboxyl group-containing acrylic resin may contain a structural unit derived from other monomers other than the above carboxyl group-containing monomer. Examples of the above other monomers include other (meth)acrylate esters other than the above thermosetting functional group-containing acrylic monomers, the above polar group-containing monomers, the above polyfunctional monomers, and the like. Only one kind of the above other monomers may be used, or two or more kinds may be used.

[0063] Examples of the above other (meth)acrylate esters include hydrocarbon group-containing (meth)acrylate esters which may have the above alkoxy group. Among the (meth)acrylate alkyl esters in the hydrocarbon group-containing (meth)acrylate esters which may have the above alkoxy group, (meth)acrylate alkyl esters having a linear or branched aliphatic hydrocarbon group having 1 to 20 carbon atoms (preferably 1 to 14, more preferably 1 to 10, still more preferably 1 to 8) are preferred. When the number of carbon atoms is within the above range, it is easier to make the flexibility of the above thermosetting group-containing acrylic resin more appropriate and the embedding property is further improved.

[0064] In order to appropriately exhibit the basic properties such as adhesion to the above-mentioned optical semiconductor element in the colored adhesive layer, the ratio of the hydrocarbon group-containing (meth)acrylate ester which may have the above-mentioned alkoxy group to the total amount (100% by mass) of all the constituent units of the above-mentioned carboxy group-containing acrylic resin is preferably 50 to 95% by mass, more preferably 60 to 90% by mass.

[0065] The weight average molecular weight of the above-mentioned carboxy group-containing acrylic resin is preferably 1,000 to 200,000, more preferably 3,000 to 100,000. When the weight average molecular weight is within the above range, the sealing property of the optical semiconductor element is more excellent. The weight average molecular weight refers to a value measured by gel permeation chromatography (GPC) and calculated in terms of polystyrene.

[0066] When the above-mentioned carboxy group-containing acrylic resin is included, the content ratio of the above-mentioned carboxy group-containing acrylic resin is preferably 5 to 60% by mass, more preferably 10 to 50% by mass, still more preferably 25 to 45% by mass, based on the total amount (100% by mass) of the resin in the above-mentioned colored adhesive layer. When the content ratio is within the above range, the heat curability of the colored adhesive layer is more excellent. Also, the surface scratch resistance is more excellent.

[0067] The above-mentioned colored adhesive layer may contain other components other than the above-mentioned respective components as long as the effects of the present invention are not impaired. Examples of the above-mentioned other components include thermoplastic resins, coupling agents such as silane coupling agents, crosslinking accelerators, tackifying resins (rosin derivatives, polyterpene resins, petroleum resins, oil-soluble phenols, etc.), oligomers, anti-aging agents, fillers (organic fillers, inorganic particles, etc.), light diffusing fine particles, antioxidants, plasticizers, softeners, surfactants, antistatic agents, surface lubricants, leveling agents, light stabilizers, ultraviolet absorbers, polymerization inhibitors, granular materials, foil materials, and the like. Each of the above-mentioned other components may be used alone or in combination of two or more.

[0068] The content ratio of the resin in the colored adhesive layer is preferably 60% by mass or more, more preferably 70% by mass or more, and still more preferably 80% by mass or more with respect to the total amount (100% by mass) of the colored adhesive layer. The content ratio is preferably 99.99% by mass or less, more preferably 99% by mass or less, and still more preferably 95% by mass or less. Further, the content ratio of the acrylic resin is preferably within the above range, the content ratio of the thermosetting resin is preferably within the above range, and the thermosetting functional group-containing acrylic resin is preferably within the above range.

[0069] The elastic modulus G' at 130°C before curing of the colored adhesive layer is preferably 0.5 to 10 kPa, more preferably 0.8 to 8 kPa, and still more preferably 1 to 8 kPa. When the elastic modulus G' is within the above range, the embedding property or followability of the optical semiconductor element is excellent.

[0070] The elastic modulus E' at room temperature (25°C) before curing of the colored adhesive layer is preferably 500 to 4000 MPa, more preferably 700 to 3800 MPa, and still more preferably 900 to 3600 MPa. When the elastic modulus E' is within the above range, stickiness is further reduced and workability is excellent.

[0071] The elastic modulus E' at room temperature after curing of the colored adhesive layer is preferably 500 to 4000 MPa, more preferably 700 to 3800 MPa, and still more preferably 900 to 3600 MPa. When the elastic modulus E' is within the above range, stickiness is further reduced and chipping is less likely to occur.

[0072] The light transmittance of the above-mentioned colored adhesive layer at a wavelength of 600 nm after curing is not particularly limited. However, from the viewpoints of improving the antireflection function of metal wirings and the like and enhancing the contrast in an optical semiconductor device, it is preferably 80% or less, more preferably 60% or less, still more preferably 40% or less, and particularly preferably 30% or less. Also, the above light transmittance is 0% or more, and from the viewpoint of ensuring the luminance of the optical semiconductor device, it is preferably 0.5% or more, more preferably 1% or more, still more preferably 1.5% or more, and particularly preferably 2% or more, and it may be 2.5% or more, or 3% or more.

[0073] The haze value of the above-mentioned colored adhesive layer is preferably 1% or more, more preferably 3% or more, still more preferably 5% or more, and particularly preferably 8% or more, and may be 10% or more, from the viewpoint of efficiently reducing luminance unevenness. The upper limit of the above haze value is not particularly limited. The above haze value may be either the value before or after curing, but the value after curing is preferred.

[0074] The total light transmittance of the above-mentioned colored adhesive layer is not particularly limited. However, from the viewpoint of exhibiting appropriate light-shielding properties, it is preferably 80% or less, more preferably 60% or less, still more preferably 40% or less, and particularly preferably 30% or less. Also, the total light transmittance of the above-mentioned colored adhesive layer is preferably 0.5% or more, more preferably 1% or more, still more preferably 1.5% or more, and particularly preferably 2% or more, and it may be 2.5% or more, or 3% or more, from the viewpoint of ensuring the luminance when the optical semiconductor element is encapsulated.

[0075] The haze value and the total light transmittance of the above-mentioned colored adhesive layer are each a value of a single layer and can be measured by the methods defined in JIS K7136 and JIS K7361-1, and can be controlled by factors such as the type, thickness, type of colorant, and blending amount.

[0076] The thickness of the colored adhesive layer (the thickness of the colored adhesive layer in contact with the optical semiconductor element) is preferably 5 to 150 μm, more preferably 7 to 100 μm, still more preferably 10 to 75 μm. When the thickness is 5 μm or more, the antireflection property is excellent. When the thickness is 150 μm or less, the brightness of the optical semiconductor device is excellent, and when it is 75 μm or less, it is even more excellent.

[0077] The colored adhesive layer can be formed using a thermosetting resin composition (adhesive composition) containing at least a colorant. The colored adhesive layer can be produced, for example, by applying the adhesive composition to the release-treated surface of a release liner or a substrate to form an adhesive composition layer, and then solidifying the adhesive composition layer by solvent removal by heating or polymerization by radiation irradiation.

[0078] (Non-colored layer) The non-colored layer is a layer different from the colored layer and is not intended to prevent light reflection by metal wiring or the like. The non-colored layer may be a colorless layer or may be slightly colored. Further, the non-colored layer may be, for example, a diffusion functional layer intended to exhibit a function of diffusing light, or a non-diffusion functional layer not intended to exhibit a function of diffusing light. The non-colored layer may be transparent or non-transparent.

[0079] The content ratio of the colorant in the non-colored layer is preferably less than 0.2% by mass, more preferably less than 0.1% by mass, still more preferably less than 0.05% by mass, and may be less than 0.01% by mass or less than 0.005% by mass, based on the total amount (100% by mass) of the non-colored layer.

[0080] The total light transmittance of the non-colored layer is not particularly limited, but from the viewpoint of ensuring brightness, it is preferably 40% or more, more preferably 60% or more, still more preferably 70% or more, and particularly preferably 80% or more. Also, the upper limit value of the total light transmittance of the non-colored layer is not particularly limited, and it may be less than 100%, or may be 99.9% or less, or 99% or less.

[0081] The total light transmittance of the non-coloring layer is a single-layer value, which can be measured by the methods defined in JIS K7136 and JIS K7361-1, and can be controlled by the type and thickness of the non-coloring layer, etc.

[0082] The diffusion functional layer is a layer for the purpose of diffusing light. When the sealing resin layer has the diffusion functional layer, the light emitted from the optical semiconductor element diffuses in the diffusion functional layer. For example, the light emitted from the side surface of the optical semiconductor element is emitted in the front direction of the image display device, and the front luminance of the image display device is improved. The diffusion functional layer is preferably a resin layer composed of resin. The diffusion functional layer preferably contains, although not limited to, light-diffusing fine particles. That is, the diffusion functional layer preferably contains light-diffusing fine particles dispersed in the resin layer. Only one type or two or more types of the light-diffusing fine particles may be used.

[0083] The light-diffusing fine particles have an appropriate refractive index difference from the resin constituting the diffusion functional layer and impart diffusion performance to the diffusion functional layer. Examples of the light-diffusing fine particles include inorganic fine particles and polymer fine particles. Examples of the material of the inorganic fine particles include silica, calcium carbonate, aluminum hydroxide, magnesium hydroxide, clay, talc, metal oxides, etc. Examples of the material of the polymer fine particles include silicone resin, acrylic resin (including polymethacrylate resins such as polymethyl methacrylate), polystyrene resin, polyurethane resin, melamine resin, polyethylene resin, epoxy resin, etc.

[0084] As the polymer fine particles, fine particles composed of silicone resin are preferable. As the inorganic fine particles, fine particles composed of metal oxides are preferable. As the metal oxides, titanium oxide and barium titanate are preferable, and titanium oxide is more preferable. By having such a configuration, the light diffusibility of the diffusion functional layer is more excellent, and luminance unevenness is more suppressed.

[0085] The shape of the above light-diffusing fine particles is not particularly limited, and may be, for example, a true spherical shape, a flat shape, or an irregular shape.

[0086] From the viewpoint of imparting appropriate light-diffusing performance, the average particle diameter of the above light-diffusing fine particles is preferably 0.1 μm or more, more preferably 0.15 μm or more, still more preferably 0.2 μm or more, and particularly preferably 0.25 μm or more. Further, from the viewpoint of preventing the haze value from becoming too high and displaying a high-definition image, the average particle diameter of the above light-diffusing fine particles is preferably 12 μm or less, more preferably 10 μm or less, and still more preferably 8 μm or less. The average particle diameter can be measured, for example, using a Coulter counter.

[0087] The refractive index of the above light-diffusing fine particles is preferably from 1.2 to 5, more preferably from 1.25 to 4.5, still more preferably from 1.3 to 4, and particularly preferably from 1.35 to 3.

[0088] From the viewpoint of more efficiently reducing the luminance unevenness of the image display device, the absolute value of the refractive index difference between the above light-diffusing fine particles and the resin constituting the diffusion functional layer (the resin layer excluding the light-diffusing fine particles in the diffusion functional layer) is preferably 0.001 or more, more preferably 0.01 or more, still more preferably 0.02 or more, and particularly preferably 0.03 or more, and may be 0.04 or more, or 0.05 or more. Further, from the viewpoint of preventing the haze value from becoming too high and displaying a high-definition image, the absolute value of the refractive index difference between the light-diffusing fine particles and the resin is preferably 5 or less, more preferably 4 or less, and still more preferably 3 or less.

[0089] From the perspective of imparting appropriate light diffusion performance to the sheet for encapsulating the optoelectronic semiconductor device, the content of the light-diffusing fine particles in the diffusion functional layer is preferably 0.01 part by mass or more, more preferably 0.05 part by mass or more, still more preferably 0.1 part by mass or more, and particularly preferably 0.15 part by mass or more, based on 100 parts by mass of the resin constituting the diffusion functional layer. Also, from the perspective of preventing the haze value from becoming too high and displaying a high-definition image, the content of the light-diffusing fine particles is preferably 80 parts by mass or less, more preferably 70 parts by mass or less, based on 100 parts by mass of the resin constituting the diffusion functional layer.

[0090] The haze value of the diffusion functional layer is not particularly limited, but from the perspective of efficiently reducing luminance unevenness, it is preferably 30% or more, more preferably 40% or more, still more preferably 50% or more, and particularly preferably 60% or more. It may also be 70% or more, 80% or more, 90% or more, 95% or more, 97% or more, and those around 99.9% are particularly preferred due to their excellent luminance unevenness improvement effect. The upper limit of the haze value of the diffusion functional layer is not particularly limited, that is, it may be 100%. When the diffusion functional layer has curability, the haze value may be any value before or after curing, but the value after curing is preferred.

[0091] The total light transmittance of the diffusion functional layer is not particularly limited, but from the perspective of ensuring luminance, it is preferably 40% or more, more preferably 60% or more, still more preferably 70% or more, and particularly preferably 80% or more. The upper limit value of the total light transmittance of the diffusion functional layer is not particularly limited, but it may be less than 100%, and may also be 99.9% or less, or 99% or less.

[0092] The haze value and the total light transmittance of the diffusion functional layer are each the value of a single layer and can be measured by the methods defined in JIS K7136 and JIS K7361-1, and can be controlled by the type and thickness of the diffusion functional layer, the type and blending amount of the light-diffusing fine particles, etc.

[0093] The haze value of the non-diffusing functional layer is not particularly limited, but from the perspective of achieving excellent luminance, it is preferably less than 30%, more preferably 10% or less, still more preferably 5% or less, particularly preferably 1% or less, and may even be 0.5% or less. The lower limit of the haze value of the non-diffusing functional layer is not particularly limited. When the non-diffusing functional layer has curability, the haze value may be any value before or after curing, but is preferably the value after curing.

[0094] The total light transmittance of the non-diffusing functional layer is not particularly limited, but from the perspective of ensuring luminance, it is preferably 60% or more, more preferably 70% or more, still more preferably 80% or more, particularly preferably 90% or more. The upper limit value of the total light transmittance of the non-diffusing functional layer is not particularly limited, and it may be less than 100%, and may also be 99.9% or less, or 99% or less.

[0095] The haze value and the total light transmittance of the non-diffusing functional layer are each the value of a single layer, which can be measured by the methods defined in JIS K7136 and JIS K7361-1, and can be controlled by the type and thickness of the non-diffusing functional layer, etc.

[0096] From the perspective of achieving excellent luminance of the image display device, the content of the colorant and / or light-diffusing fine particles in the non-diffusing functional layer is preferably less than 0.01 part by mass, more preferably less than 0.005 part by mass, based on 100 parts by mass of the resin constituting the non-diffusing functional layer.

[0097] From the perspective of excellent workability and chipping prevention of the sheet for encapsulating the optoelectronic element, the non-coloring layer is preferably an adhesive layer. It is also preferably thermosetting.

[0098] The above non-coloring layer is preferably a resin layer composed of a resin. As the above resin, known or commonly used resins can be mentioned. For example, those exemplified and described as the resins that the above coloring adhesive layer may contain can be mentioned. Only one kind of the above resin may be used, or two or more kinds may be used. Among them, an acrylic resin is preferable.

[0099] From the viewpoint of having thermosetting properties, the above non-coloring layer preferably contains a thermosetting resin. As the above thermosetting resin, known or commonly used thermosetting resins can be used. For example, those exemplified and described as the resins having thermosetting functional groups that the above coloring adhesive layer may contain can be mentioned. Among them, as the above thermosetting resin, the above thermosetting functional group-containing acrylic resin is preferable. As the thermosetting functional group of the above thermosetting functional group-containing acrylic resin, an epoxy group-containing group is preferable, and more preferably a glycidyl group. That is, as the above thermosetting functional group-containing acrylic resin, a glycidyl group-containing acrylic resin is particularly preferable. The above thermosetting functional group may have only one kind, or may have two or more kinds.

[0100] Among the above thermosetting functional group-containing acrylic monomers, an epoxy group-containing (meth)acrylate is preferable, and more preferably a glycidyl group-containing (meth)acrylate. When the above acrylic resin contains a structural unit derived from an epoxy group-containing (meth)acrylate, the epoxy group acts as a thermosetting functional group, and even when no curing agent is blended, the reaction of the epoxy group proceeds by thermosetting, and the above non-coloring layer cures. Therefore, the above non-coloring layer has appropriate flexibility after thermosetting and is excellent in the sealing property of the optical semiconductor element.

[0101] The content ratio of the structural unit derived from the above epoxy group-containing (meth)acrylate is preferably 5 to 50% by mass, more preferably 6 to 45% by mass, based on the total amount (100% by mass) of all the structural units of the acrylic resin in the above non-coloring layer. When the above content ratio is within the above range, the above non-coloring layer has appropriate flexibility after thermosetting and is excellent in the sealing property of the optical semiconductor element.

[0102] The above-mentioned acrylic resin containing a thermosetting functional group may contain a structural unit derived from the above-mentioned other monomer. Examples of the above-mentioned other monomer include the above-mentioned other (meth)acrylic acid ester. Only one kind of the above-mentioned other monomer may be used, or two or more kinds may be used.

[0103] As the above-mentioned other (meth)acrylic acid ester, an (meth)acrylic acid alkyl ester having the above-mentioned linear or branched aliphatic hydrocarbon group is preferable. Among them, an (meth)acrylic acid alkyl ester having a linear or branched aliphatic hydrocarbon group with 1 to 20 carbon atoms (preferably 1 to 14, more preferably 2 to 10, still more preferably 2 to 8) is preferable. When the number of carbon atoms is within the above range, the flexibility of the above-mentioned acrylic resin containing a thermosetting group during thermosetting can be more appropriately adjusted, and the embedding property is further improved.

[0104] The content ratio of the above-mentioned acrylic resin containing an epoxy group is preferably 40% by mass or more (for example, 40 to 100% by mass), more preferably 50% by mass or more, and still more preferably 60% by mass or more, based on the total amount (100% by mass) of the resin in the above-mentioned non-coloring layer. When the content ratio is 40% by mass or more, the embedding property of the optical semiconductor element is more excellent.

[0105] The above-mentioned non-coloring layer preferably contains a component having a functional group (second functional group) capable of reacting with heat with the thermosetting functional group (first functional group) in the above-mentioned acrylic resin containing a thermosetting functional group. The above-mentioned second functional group is also a thermosetting functional group. In this case, when the non-coloring layer is heated, the reaction between the above-mentioned first functional group and the above-mentioned second functional group promotes the curing of the non-coloring layer more. Examples of the combination of the above-mentioned first functional group and the above-mentioned second functional group include those exemplified and described as the combination in the above-mentioned acrylic resin containing a thermosetting functional group that the above-mentioned colored adhesive layer may contain.

[0106] The component having the second functional group may be a thermosetting functional group-containing acrylic resin having the first functional group, a thermosetting functional group-containing acrylic resin other than the thermosetting functional group-containing acrylic resin having the first functional group, or another component having the second functional group. Only one kind of the component having the second functional group may be used, or two or more kinds may be used.

[0107] When the epoxy group-containing acrylic resin is included, it is preferable that the non-coloring layer contains, as the component having the second functional group, a component having a functional group reactive with the epoxy group. Examples of the functional group reactive with the epoxy group include a carboxy group, an aziridyl group, a hydroxy group, etc. Among them, a carboxy group and a hydroxy group are preferable. From the viewpoint of high acidity and excellent reactivity with the epoxy group, a silanol group is preferable as the hydroxy group.

[0108] The component having the carboxy group is preferably the above resin, more preferably the carboxy group-containing acrylic resin (the carboxy group-containing acrylic resin exemplified and described as what the colored adhesive layer may contain). When the carboxy group-containing acrylic resin is contained, the reaction between the epoxy group and the carboxy group in the epoxy group-containing acrylic resin proceeds more easily even when no curing agent is blended, and the sealing property of the optical semiconductor element is more excellent. Also, the surface scratch resistance is even more excellent.

[0109] The content ratio of the structural unit derived from the carboxy group-containing acrylic monomer is preferably 1 to 50% by mass, more preferably 10 to 40% by mass, based on the total amount (100% by mass) of all the structural units of the carboxy group-containing acrylic resin. When the content ratio is within the above range, the non-coloring layer has appropriate flexibility after thermosetting and is more excellent in the sealing property of the optical semiconductor element.

[0110] The carboxy group-containing acrylic resin may contain structural units derived from other monomers other than the carboxy group-containing monomer. Examples of the other monomers include other (meth)acrylic acid esters other than the thermosetting functional group-containing acrylic monomer, the polar group-containing monomer, the polyfunctional monomer, and the like. Only one kind of the other monomers may be used, or two or more kinds may be used.

[0111] Examples of the other (meth)acrylic acid esters include hydrocarbon group-containing (meth)acrylic acid esters which may have the alkoxy group. Among the (meth)acrylic acid alkyl esters in the hydrocarbon group-containing (meth)acrylic acid ester which may have the alkoxy group, (meth)acrylic acid alkyl esters having a linear or branched aliphatic hydrocarbon group having 1 to 20 carbon atoms (preferably 1 to 14 carbon atoms, more preferably 1 to 10 carbon atoms, still more preferably 1 to 8 carbon atoms) are preferable. When the number of carbon atoms is within the above range, the flexibility of the thermosetting group-containing acrylic resin is more easily made appropriate, and the embedding property is further improved.

[0112] In order to appropriately exhibit basic properties such as adhesion to the optical semiconductor element in the non-coloring layer, the ratio of the hydrocarbon group-containing (meth)acrylic acid ester having the alkoxy group to the total amount (100% by mass) of all the structural units of the carboxy group-containing acrylic resin is preferably 50 to 95% by mass, more preferably 60 to 90% by mass.

[0113] When the carboxy group-containing acrylic resin is included, the content ratio of the carboxy group-containing acrylic resin in the resin is preferably 5 to 60% by mass, more preferably 10 to 50% by mass, still more preferably 25 to 45% by mass with respect to the total amount (100% by mass) of the resin in the non-coloring layer. When the content ratio is within the above range, the non-coloring layer is excellent in thermosetting property. Also, the surface is excellent in scratch resistance.

[0114] The content ratio of the resin in the non-coloring layer is preferably 60% by mass or more, more preferably 70% by mass or more, and even more preferably 80% by mass or more with respect to the total amount (100% by mass) of the non-coloring layer. The content ratio is 100% by mass or less, may be 99.99% by mass or less, and may also be 99% by mass or less, 95% by mass or less. Further, the content ratio of the acrylic resin is preferably within the above range, and the thermosetting functional group-containing acrylic resin is preferably within the above range.

[0115] The non-coloring layer may contain other components other than the above-mentioned components as long as the effects of the present invention are not impaired. Examples of the other components include those exemplified and described as the other components that the coloring adhesive layer may contain. Each of the other components may be used alone or in combination of two or more.

[0116] The elastic modulus G' at 130°C before curing of the non-coloring layer is preferably 0.5 to 10 kPa, more preferably 0.6 to 8 kPa, and even more preferably 0.8 to 8 kPa. When the elastic modulus G' is within the above range, the embedding property or followability of the optical semiconductor element is excellent.

[0117] The elastic modulus E' at room temperature (25°C) before curing of the non-coloring layer is preferably 500 to 4000 MPa, more preferably 700 to 3800 MPa, and even more preferably 900 to 3600 MPa. When the elastic modulus E' is within the above range, stickiness is further reduced and workability is excellent.

[0118] The light transmittance at a wavelength of 600 nm after curing of the non-coloring layer is not particularly limited, but from the viewpoint of further improving the luminance of the optical semiconductor device, it is preferably more than 80%, more preferably 85% or more, and even more preferably 90% or more. The light transmittance is 100% or less.

[0119] The room temperature elastic modulus E' of the non-coloring layer after curing is preferably 500 to 4000 MPa, more preferably 700 to 3800 MPa, and still more preferably 900 to 3600 MPa. When the elastic modulus E' is within the above range, stickiness is further reduced and chipping is less likely to occur.

[0120] The thickness of the non-coloring layer (the thickness of the non-coloring layer closest to the optical semiconductor element side in the resin layer for sealing) is preferably 5 to 200 μm, more preferably 8 to 160 μm, and still more preferably 30 to 150 μm. When the thickness is 5 μm or more, the sealing property of the optical semiconductor element is more excellent. When the thickness is 200 μm or less, the luminance of the optical semiconductor device is more excellent.

[0121] The non-coloring layer can be formed using, for example, a thermosetting resin composition (adhesive composition). The non-coloring layer can be produced, for example, by applying the adhesive composition to the release-treated surface of a release liner or a substrate to form an adhesive composition layer, and then solidifying the adhesive composition layer by removing the solvent by heating or by polymerization by radiation irradiation.

[0122] Examples of the layer structure of the resin layer for sealing include [colored adhesive layer], [colored adhesive layer / diffusion functional layer], [colored adhesive layer / non-diffusion functional layer], [colored adhesive layer / diffusion functional layer / non-diffusion functional layer], [colored adhesive layer / non-diffusion functional layer / diffusion functional layer], [colored adhesive layer / diffusion functional layer / diffusion functional layer], [colored adhesive layer / non-diffusion functional layer / non-diffusion functional layer][colored adhesive layer / diffusion functional layer / colored adhesive layer / non-diffusion functional layer] (in the order from the optical semiconductor element side).

[0123] (Base material part) In the sheet for encapsulating an optical semiconductor device of the present invention, the encapsulating resin layer may be provided on at least one surface of the base material portion. That is, the sheet for encapsulating a semiconductor device may include a base material portion and the encapsulating resin layer provided on at least one surface of the base material portion. When the sheet for encapsulating an optical semiconductor device of the present invention includes the base material portion, the side of the encapsulating resin layer opposite to the colored adhesive layer is the side that contacts the base material portion. If the base material portion is provided on the side opposite to the optical semiconductor device side of the encapsulating resin layer in the sheet for encapsulating an optical semiconductor device, the surface of the encapsulating resin layer can be made flat, making it less likely to cause irregular reflection of light, and improving the appearance of the optical semiconductor device both when it is turned off and when it is emitting light. Also, by forming an anti-glare layer or an anti-reflection layer, which will be described later, on the base material portion, anti-glare properties and anti-reflection properties can be imparted to the optical semiconductor device. Further, in the sheet for encapsulating an optical semiconductor device, it serves as a support for the encapsulating resin layer, and having the base material portion provides excellent handleability of the sheet for encapsulating an optical semiconductor device. Note that the base material portion does not necessarily have to be provided.

[0124] The base material portion may be a single layer or a multi-layer in which the layers are the same or have different compositions, thicknesses, etc. When the base material portion is a multi-layer, the layers may be bonded together by other layers such as an adhesive layer. Note that the base material layer used for the base material portion is the portion that is attached to the adherend together with the encapsulating resin layer, and a release liner that is peeled off when the sheet for encapsulating an optical semiconductor device is used (attached) or a surface protection film that only protects the surface of the base material portion is not included in the "base material portion".

[0125] Examples of the base material layer constituting the base material portion include glass and plastic base materials (particularly plastic films). Examples of the resin constituting the plastic base material include polyolefin resins such as low-density polyethylene, linear low-density polyethylene, medium-density polyethylene, high-density polyethylene, ultra-low-density polyethylene, random copolymer polypropylene, block copolymer polypropylene, homopolypropylene, polybutene, polymethylpentene, ionomer, ethylene-(meth)acrylic acid copolymer, ethylene-(meth)acrylate (random, alternating) copolymer, ethylene-vinyl acetate copolymer (EVA), ethylene-propylene copolymer, cyclic olefin-based polymer, ethylene-butene copolymer, ethylene-hexene copolymer; polyurethane; polyesters such as polyethylene terephthalate (PET), polyethylene naphthalate, polybutylene terephthalate (PBT); polycarbonate; polyimide-based resin; polyether ether ketone; polyether imide; polyamides such as aramid and wholly aromatic polyamide; polyphenyl sulfide; fluororesin; polyvinyl chloride; polyvinylidene chloride; cellulose resins such as triacetyl cellulose (TAC); silicone resin; acrylic resins such as polymethyl methacrylate (PMMA); polysulfone; polyarylate; polyvinyl acetate, etc. The above resins may be used alone or in combination of two or more. The base material layer may be various optical films such as an antireflection (AR) film, a polarizing plate, and a retardation plate.

[0126] The thickness of the plastic film is preferably 20 to 300 μm, more preferably 40 to 250 μm. When the thickness is 20 μm or more, the supportability and handleability of the sheet for encapsulating the optoelectronic device are further improved. When the thickness is 300 μm or less, the sheet for encapsulating the optoelectronic device can be made thinner.

[0127] The surface of the base material portion on the side provided with the resin layer for sealing is, for the purpose of enhancing adhesion, retention, etc. with the resin layer for sealing, subjected to physical treatments such as corona discharge treatment, plasma treatment, sand mat processing treatment, ozone exposure treatment, flame exposure treatment, high-voltage electric shock exposure treatment, ionization radiation treatment, etc.; chemical treatments such as chromic acid treatment; surface treatments such as easy adhesion treatment with a coating agent (primer), etc. may be performed. The surface treatment for enhancing adhesion is preferably performed on the entire surface of the base material portion on the side of the resin layer for sealing.

[0128] From the viewpoint of excellent functions as a support and scratch resistance of the surface, the thickness of the base material portion is preferably 5 μm or more, more preferably 10 μm or more. From the viewpoint of more excellent transparency, the thickness of the base material portion is preferably 300 μm or less, more preferably 250 μm or less.

[0129] <Sheet for Sealing Optical Semiconductor Element> The sheet for sealing an optical semiconductor element may include a layer having antiglare properties and / or antireflection properties. By having such a configuration, when the optical semiconductor element is sealed, gloss and light reflection can be suppressed, and the appearance can be made better. Examples of the layer having antiglare properties include an antiglare treatment layer. Examples of the layer having antireflection properties include an antireflection treatment layer. The antiglare treatment and the antireflection treatment can each be performed by a known or commonly used method. The layer having antiglare properties and the layer having antireflection properties may be the same layer or different layers from each other. The layer having antiglare properties and / or antireflection properties may have only one layer or two or more layers. The layer having antiglare properties and / or antireflection properties is preferably provided on the surface (preferably the surface) of the sheet for sealing an optical semiconductor element on the side opposite to the side in contact with the optical semiconductor element of the sheet, with respect to the resin layer for sealing.

[0130] The haze value of the sheet for encapsulating the optical semiconductor device is preferably 1% or more, more preferably 3% or more, still more preferably 5% or more, particularly preferably 8% or more, and may be 10% or more, from the viewpoint of efficiently reducing luminance unevenness. The upper limit of the haze value is not particularly limited. The haze value may be either the value before or after curing, but is preferably the value after curing.

[0131] The total light transmittance of the sheet for encapsulating the optical semiconductor device is not particularly limited, but is preferably 40% or less, more preferably 30% or less, still more preferably 20% or less, from the viewpoints of antireflection function such as metal wiring and further improving contrast. Also, the total light transmittance is preferably 0.5% or more from the viewpoint of ensuring luminance.

[0132] The haze value and the total light transmittance can be measured by the methods defined in JIS K7136 and JIS K7361-1, respectively, and can be controlled by the lamination order, type, thickness, etc. of each layer constituting the encapsulating resin layer and the base material portion.

[0133] When the optical semiconductor device is encapsulated with the sheet for encapsulating the optical semiconductor device, the distance from the optical semiconductor device to the colored adhesive layer (the colored adhesive layer closest to the optical semiconductor device side in the encapsulating resin layer) is preferably 0 to 20 μm, more preferably 0 to 10 μm. When the distance is within the above range, the antireflection property and luminance of the image display device are more excellent.

[0134] The thickness of the sheet for encapsulating the optical semiconductor device is preferably 5 to 600 μm, more preferably 10 to 550 μm, still more preferably 30 to 500 μm, still more preferably 40 to 450 μm, particularly preferably 50 to 400 μm, from the viewpoints of antireflection function such as metal wiring, improving contrast, and more efficiently reducing color shift. Note that the release liner is not included in the above thickness.

[0135] The thickness of the above-mentioned resin layer for sealing is, for example, 5 to 500 μm, preferably 10 to 400 μm, and more preferably 100 to 300 μm. When the above thickness is 5 μm or more, the sealing property of the optical semiconductor element becomes better. When the above thickness is 500 μm or less, the thickness of the optical semiconductor device becomes thinner.

[0136] [Release Liner] The above-mentioned resin layer for sealing may be formed on the release-treated surface of the release liner. When the above-mentioned resin layer for sealing is formed on the above-mentioned release liner, the above-mentioned colored adhesive layer (the colored adhesive layer closest to the optical semiconductor element side in the above-mentioned resin layer for sealing) is on the side in contact with the above-mentioned release liner. When there is no above-mentioned base material portion, both surfaces of the above-mentioned resin layer for sealing may be on the side in contact with the release liner. The release liner is used as a protective material for the above-mentioned optical semiconductor element sealing sheet and is peeled off when sealing the optical semiconductor element. Note that the release liner is not necessarily provided.

[0137] The above-mentioned release liner is an element for covering and protecting the surface of the above-mentioned optical semiconductor element sealing sheet, and is peeled off from the sheet when the optical semiconductor element sealing sheet is bonded to the substrate on which the optical semiconductor element is disposed.

[0138] Examples of the above-mentioned release liner include polyethylene terephthalate (PET) films, polyethylene films, polypropylene films, plastic films and papers surface-coated with release agents such as fluorine-based release agents and long-chain alkyl acrylate-based release agents.

[0139] The thickness of the above-mentioned release liner is, for example, 10 to 200 μm, preferably 15 to 150 μm, and more preferably 20 to 100 μm. When the above thickness is 10 μm or more, it is difficult to break due to cuts during the processing of the release liner. When the above thickness is 200 μm or less, it is easier to peel the release liner from the above-mentioned optical semiconductor element sealing sheet during use.

[0140] Figures 1 and 2 are cross-sectional views showing an embodiment of the sheet for encapsulating an optical semiconductor device of the present invention. As shown in FIGS. 1 and 2, the sheet 1 for encapsulating an optical semiconductor device can be used to encapsulate one or more optical semiconductor devices disposed on a substrate, and includes a base material portion 4 and a resin layer 2 for encapsulation formed on the base material portion 4. The base material portion 4 is composed of a base material film 41 and a functional layer 42 which is a surface treatment layer, but it may be composed of only the base material film 41 without the functional layer 42.

[0141] In the sheet 1 for encapsulating an optical semiconductor device shown in FIG. 1, the resin layer 2 for encapsulation is formed of a single layer of a colored adhesive layer 21. A release liner 3 is attached to one surface of the colored adhesive layer 21, and the base material portion 4 is attached to the other surface.

[0142] In the sheet 1 for encapsulating an optical semiconductor device shown in FIG. 2, the resin layer 2 for encapsulation is formed from a laminate of a colored adhesive layer 21 and a non-colored layer 22. The non-colored layer 22 is directly laminated on the colored adhesive layer 21. A release liner 3 is attached to the colored adhesive layer 21, and the base material portion 4 is attached to the non-colored layer 22.

[0143] In FIGS. 1 and 2, the functional layer 42 is a layer not included in the resin layer for encapsulation, and examples of the layer that can impart various functions for encapsulating the optical semiconductor device include layers having the above-described functions. Examples of the functional layer include a layer including a surface treatment layer. By having such a configuration, the sheet for encapsulating an optical semiconductor device having a functional layer including a surface treatment layer laminated thereon is excellent in light diffusibility and light extraction efficiency. Examples of the surface treatment layer include an antiglare treatment layer (antiglare treatment layer), an antireflection treatment layer, a hard coat treatment layer, and the like. The functional layer may be laminated on the resin layer for encapsulation in the sheet for encapsulating an optical semiconductor device, or may be laminated on the base material portion when the base material portion is provided. However, it is preferably laminated on the base material portion, and more preferably laminated on the side opposite to the side having the resin layer for encapsulation of the base material portion.

[0144] [Method for manufacturing a sheet for encapsulating an optical semiconductor device] An embodiment of the method for manufacturing the sheet for encapsulating an optical semiconductor element will be described. For example, for the sheet 1 for encapsulating an optical semiconductor element shown in FIG. 1, a colored adhesive layer 21 is formed between the release-treated surfaces of two release liners. One of the release liners bonded to the colored adhesive layer 21 is the release liner 3. Next, one of the release liners (the release liner other than the release liner 3) bonded to the colored adhesive layer 21 is peeled off to expose the surface of the colored adhesive layer 21, and the exposed surface is bonded to the base material portion 4. In this way, the sheet 1 for encapsulating an optical semiconductor element shown in FIG. 1, in which the colored adhesive layer 21 and the release liner 3 are laminated in this order on the base material portion 4, can be manufactured.

[0145] Also, for the sheet 1 for encapsulating an optical semiconductor element shown in FIG. 2, for example, a colored adhesive layer 21 and a non-colored layer 22 are separately formed between the release-treated surfaces of two release liners each. One of the release liners bonded to the colored adhesive layer 21 is the release liner 3. Next, one of the release liners bonded to the non-colored layer 22 is peeled off to expose the surface of the non-colored layer 22, and the exposed surface is bonded to the base material portion 4. Then, one of the release liners (the release liner other than the release liner 3) bonded to the colored adhesive layer 21 is peeled off, and the release liner on the surface of the non-colored layer 22 is peeled off to expose the surface of the non-colored layer 22, and the exposed surface of the colored adhesive layer 21 is bonded to the exposed surface of the non-colored layer 22. The lamination of the various layers can be performed using a known roller or laminator. In this way, the sheet 1 for encapsulating an optical semiconductor element shown in FIG. 2, in which the non-colored layer 22, the colored adhesive layer 21, and the release liner 3 are laminated in this order on the base material portion 4, can be manufactured.

[0146] [Optical Semiconductor Device] An optical semiconductor device such as an image display device can be manufactured using the above-mentioned sheet for encapsulating an optical semiconductor element. The optical semiconductor device manufactured using the above-mentioned sheet for encapsulating an optical semiconductor element includes a substrate, an optical semiconductor element disposed on the substrate, and the above-mentioned sheet for encapsulating an optical semiconductor element or a cured product obtained by curing the sheet that encapsulates the optical semiconductor element. The cured product is a cured product obtained by thermally curing the thermosetting colored adhesive layer 21 (or further the non-colored layer 22) provided in the above-mentioned sheet for encapsulating an optical semiconductor element. Specifically, it includes a cured encapsulation layer obtained by thermally curing the colored adhesive layer 21.

[0147] Examples of the above-mentioned optical semiconductor element include light-emitting diodes (LEDs) such as blue light-emitting diodes, green light-emitting diodes, red light-emitting diodes, and ultraviolet light-emitting diodes.

[0148] In the above-mentioned optical semiconductor device, since the above-mentioned sheet for encapsulating an optical semiconductor element is excellent in followability to unevenness when the optical semiconductor element is a convex portion and the gaps between a plurality of optical semiconductor elements are concave portions, and is excellent in followability and embedability of the optical semiconductor element, it is preferable to encapsulate a plurality of optical semiconductor elements collectively.

[0149] FIG. 3 shows an embodiment of an optical semiconductor device using the sheet 1 for encapsulating an optical semiconductor element shown in FIG. 1. The optical semiconductor device 10 shown in FIG. 3 includes a substrate 5, a plurality of optical semiconductor elements 6 disposed on one surface of the substrate 5, and a cured product of the sheet 1 for encapsulating an optical semiconductor element that encapsulates the optical semiconductor elements 6. The cured product of the sheet for encapsulating an optical semiconductor element is formed by peeling the release liner 3 from the sheet 1 for encapsulating an optical semiconductor element and thermally curing the colored adhesive layer 21 to form a cured encapsulation layer 7. The cured encapsulation layer 7 is composed of a colored adhesive layer 71 obtained by thermally curing the colored adhesive layer 21. The plurality of optical semiconductor elements 6 are collectively encapsulated in the cured encapsulation layer 7. The cured encapsulation layer 7 follows the uneven shape formed by the plurality of optical semiconductor elements 6 and is in close contact with the optical semiconductor elements 6 and the substrate 5, embedding the optical semiconductor elements 6. Further, the cured encapsulation layer 7 follows the uneven shape and the interface on the optical semiconductor element 6 side has an uneven shape, while the other interface is flat.

[0150] FIG. 4 shows an embodiment of an optical semiconductor device using the sheet 1 for sealing an optical semiconductor element shown in FIG. 2. The optical semiconductor device 10 shown in FIG. 4 includes a substrate 5, a plurality of optical semiconductor elements 6 disposed on one surface of the substrate 5, and a cured product of the sheet 1 for sealing an optical semiconductor element. The cured product of the sheet for sealing an optical semiconductor element is formed by peeling the release liner 3 from the sheet 1 for sealing an optical semiconductor element and thermally curing the colored adhesive layer 21 and the non-colored layer 22 to form a cured sealing layer 7. For example, the cured sealing layer 7 includes a colored adhesive layer 71 formed by thermally curing the colored adhesive layer 21 and a non-colored layer 72 formed by thermally curing the non-colored layer 22. The plurality of optical semiconductor elements 6 are collectively sealed in the cured sealing layer 7. The cured sealing layer 7 follows the uneven shape formed by the plurality of optical semiconductor elements 6 and adheres closely to the optical semiconductor elements 6 and the substrate 5, embedding the optical semiconductor elements 6. Further, the cured sealing layer 7 follows the uneven shape, and the interface on the optical semiconductor element 6 side has an uneven shape, and the other interface is flat.

[0151] In the optical semiconductor device 10 shown in FIG. 4, the optical semiconductor element 6 is completely embedded and sealed in the colored adhesive layer 71 and is indirectly sealed by the non-colored layer 72. That is, the optical semiconductor element 6 is sealed by the cured sealing layer 7 composed of a laminate of the colored adhesive layer 71 and the non-colored layer 72. The above optical semiconductor device is not limited to such a mode. For example, as shown in FIG. 5, the optical semiconductor element 6 may be completely embedded and sealed in the colored adhesive layer 71 and the non-colored layer 72.

[0152] As described above, the above optical semiconductor device seals the optical semiconductor element with the cured sealing layer. The colored adhesive layer has sufficient flexibility before thermal curing, so it has excellent uneven following properties, fully embeds the optical semiconductor element, and fixes the optical semiconductor element after thermal curing. Therefore, the optical semiconductor element adheres closely to the cured sealing layer, and the sealing property of the optical semiconductor element is excellent. In addition, since the side surface of the colored adhesive layer has low adhesiveness, the workability is excellent. Also, in the tiled state, when separating adjacent optical semiconductor devices from each other, they can be easily separated, and sheet breakage and adhesion of the sheet of adjacent optical semiconductor devices are less likely to occur.

[0153] The above-mentioned optical semiconductor device may be one in which individual optical semiconductor devices are tiled. That is, the above-mentioned optical semiconductor device may be one in which a plurality of optical semiconductor devices are arranged in a tile shape in the planar direction.

[0154] FIG. 6 shows an embodiment of an optical semiconductor device fabricated by arranging a plurality of optical semiconductor devices. The optical semiconductor device 20 shown in FIG. 6 is one in which a total of 16 optical semiconductor devices 10, 4 in the vertical direction and 4 in the horizontal direction, are arranged in a tile shape in the planar direction (tiling). At the boundary 20a between two adjacent optical semiconductor devices 10, the optical semiconductor devices 10 are adjacent to each other, but they can be easily separated, and it is difficult for defects to occur on the side surface of the cured encapsulation layer 7 or for resin that is missing on the side surface of the cured encapsulation layer to adhere from one of the adjacent optical semiconductor devices to the other.

[0155] The above-mentioned image display device preferably includes a self-emitting display device. Further, an image display device can be formed by combining the above-mentioned self-emitting display device and, if necessary, a display panel. In this case, the optical semiconductor element is an LED element. Examples of the above-mentioned self-emitting display device include an LED display, a backlight, or an organic electroluminescence (organic EL) display device. The above-mentioned backlight is particularly preferably a full-array direct-lit backlight. The above-mentioned backlight includes, for example, at least a part of a laminate including the above-mentioned substrate and a plurality of optical semiconductor elements arranged on the substrate as a constituent member. For example, in the above-mentioned self-emitting display device, a metal wiring layer for sending a light emission control signal to each LED element is laminated on the above-mentioned substrate. Each LED element that emits light of each color of red (R), green (G), and blue (B) is alternately arranged on the substrate via the metal wiring layer. The metal wiring layer is formed of a metal such as copper, and adjusts the light emission intensity of each LED element to display each color.

[0156] The sheet for encapsulating the optical semiconductor element can be used for an optical semiconductor device that is bent and used, for example, an optical semiconductor device having a foldable image display device (flexible display) (particularly, a foldable image display device (foldable display)). Specifically, it can be used for a foldable backlight and a foldable self-emitting display device, etc.

[0157] Since the sheet for encapsulating the optical semiconductor element is excellent in followability and embeddability of the optical semiconductor element, it can be preferably used in both the case where the optical semiconductor device is a mini-LED display device and the case where it is a micro-LED display device.

[0158] [Manufacturing method of optical semiconductor device] The optical semiconductor device is, for example, a step of bonding the sheet for encapsulating the optical semiconductor element to the optical semiconductor element provided on the substrate to encapsulate the optical semiconductor element with the encapsulating resin layer (encapsulation step), and heating a laminate including the substrate, the optical semiconductor element disposed on the substrate, and the sheet for encapsulating the optical semiconductor element that encapsulates the optical semiconductor element obtained through the encapsulation step to cure the colored adhesive layer to obtain the cured product (heating step). The cured product is a cured product obtained by thermally curing the colored adhesive layer. Specifically, it includes a cured encapsulation layer obtained by thermally curing the colored adhesive layer.

[0159] The manufacturing method may further include a step of dicing the laminate obtained through the heating step to obtain an optical semiconductor device (dicing step). Also, the manufacturing method may further include a tiling step of arranging a plurality of optical semiconductor devices obtained in the dicing step so as to be in contact in the planar direction. Hereinafter, the manufacturing method of the optical semiconductor device 10 shown in FIG. 3 and the optical semiconductor device 20 shown in FIG. 6 will be described with appropriate reference.

[0160] (Encapsulation step) In a method of manufacturing an optical semiconductor device using the sheet for encapsulating an optical semiconductor element, the method has an encapsulation step of bonding the sheet for encapsulating an optical semiconductor element to a substrate on which the optical semiconductor element is disposed and encapsulating the optical semiconductor element with an encapsulating resin layer. In the encapsulation step, specifically, first, a release liner is peeled off from the sheet for encapsulating an optical semiconductor element to expose the encapsulating resin layer. Then, the exposed surface of the sheet for encapsulating an optical semiconductor element is bonded to the substrate surface of a laminate (such as an optical member) including the substrate and the optical semiconductor element (preferably a plurality of optical semiconductor elements) disposed on the substrate. When the laminate includes a plurality of optical semiconductor elements, the encapsulating resin layer is further arranged to fill the gaps between the plurality of optical semiconductor elements, and the plurality of optical semiconductor elements are encapsulated together. Specifically, the release liner 3 is peeled off from the sheet 1 for encapsulating an optical semiconductor element shown in FIG. 1 or FIG. 2 to expose the colored adhesive layer 21, and the colored adhesive layer 21 is arranged to face the surface of the substrate 5 on which the optical semiconductor element 6 is disposed. The sheet 1 for encapsulating an optical semiconductor element is bonded to the surface of the substrate 5 on which the optical semiconductor element 6 is disposed, and the optical semiconductor element 6 is embedded in or closely adhered to the encapsulating resin layer 2.

[0161] The temperature during the bonding is, for example, within the range from room temperature to 150°C. Also, during the bonding, reduced pressure or increased pressure may be applied. By reducing or increasing the pressure, it is possible to suppress the formation of voids between the encapsulating resin layer and the substrate or the optical semiconductor element. Further, in the encapsulation step, it is preferable to bond the sheet for encapsulating an optical semiconductor element under reduced pressure and then apply pressure. The pressure during reduced pressure is, for example, 1 to 100 Pa, and the reduced pressure time is, for example, 5 to 600 seconds. Also, the pressure during pressure application is, for example, 0.05 to 0.5 MPa, and the pressure application time is, for example, 5 to 600 seconds.

[0162] (Heating step) In the above heating process, the laminate (for example, the laminate obtained in the above sealing process) in which the sheet for sealing the optical semiconductor element is bonded to the substrate on which the optical semiconductor element is disposed is heated to cure the colored adhesive layer. Specifically, in the above heating process, as shown in FIG. 3, the colored adhesive layer 21 is cured to form the cured sealing layer 7, and a cured product of the sheet for sealing the optical semiconductor element 1 is obtained. The temperature during the heating is, for example, in the range of 80 to 200 ° C, and the heating time is, for example, 1 minute to 24 hours.

[0163] (Dicing Process) In the above dicing process, the laminate that has undergone the above heating process is diced. Here, in the laminate to be subjected to the dicing process, the cured product of the sheet for sealing the optical semiconductor element and the substrate 5 extend wider in the plane direction than the finally obtained optical semiconductor device 10. Then, in the above dicing process, the cured product of the sheet for sealing the optical semiconductor element and the side end portions of the substrate are diced and removed. The dicing can be performed by a known or conventional method, for example, a method using a dicing blade or a method using laser irradiation. In this way, for example, the optical semiconductor device 10 shown in FIG. 3 can be manufactured.

[0164] (Tiling Process) In the above tiling process, a plurality of optical semiconductor devices obtained in the above dicing process are tiled by arranging them in contact with each other in the plane direction. In this way, for example, the optical semiconductor device 20 (for example, one large image display device) shown in FIG. 6 can be manufactured. The optical semiconductor devices obtained by tiling are excellent in the sealing property of the optical semiconductor element, and when separating adjacent optical semiconductor devices from each other, sheet defects and adhesion of the sheets of adjacent optical semiconductor devices are less likely to occur.

Example

[0165] The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples in any way.

[0166] Preparation Example 1 (Preparation of Colored Adhesive Layer 1) 55 parts by mass of acrylic polymer A1 (glycidyl methacrylate (GMA): ethyl acrylate (EA): butyl methacrylate (BMA) = 34% by mass: 30% by mass: 36% by mass, weight average molecular weight 60,000), 32 parts by mass of acrylic resin B (trade name "UC-3000", carboxyl group-containing acrylic resin, manufactured by Toagosei Co., Ltd.), 10 parts by mass of "Carbon Black #20" (manufactured by Mitsubishi Chemical Corporation), and 3 parts by mass of a silane coupling agent (trade name "KBM-303", manufactured by Shin-Etsu Chemical Co., Ltd.) were dissolved in methyl ethyl ketone to prepare a resin composition solution 1 having a solid content concentration of 50% by mass. After applying the resin composition solution 1 onto the release-treated surface of a release liner (a release-treated film made of a polyethylene terephthalate film having a thickness of 38 μm and subjected to a silicone release treatment), it was dried at 130°C for 2 minutes to produce a sheet-like thermosetting resin composition (colored adhesive layer 1) having a thickness (average thickness) of 10 μm.

[0167] Preparation Example 2 (Preparation of Colored Adhesive Layer 2) 68 parts by mass of acrylic polymer A2 (glycidyl methacrylate (GMA): ethyl acrylate (EA): butyl methacrylate (BMA) = 34% by mass: 26% by mass: 40% by mass, weight average molecular weight 100,000), 28.8 parts by mass of acrylic resin B (trade name "UC-3000", carboxyl group-containing acrylic resin, manufactured by Toagosei Co., Ltd.), 0.1 part by mass of "Carbon Black #20" (manufactured by Mitsubishi Chemical Corporation), and 3 parts by mass of a silane coupling agent (trade name "KBM-303", manufactured by Shin-Etsu Chemical Co., Ltd.) were dissolved in methyl ethyl ketone to prepare a resin composition solution 2 having a solid content concentration of 50% by mass. After applying the resin composition solution 2 onto the release-treated surface of a release liner (a release-treated film made of a polyethylene terephthalate film having a thickness of 38 μm and subjected to a silicone release treatment), it was dried at 130°C for 2 minutes to produce a sheet-like thermosetting resin composition (colored adhesive layer 2) having a thickness (average thickness) of 40 μm.

[0168] Preparation Example 3 (Preparation of Colored Adhesive Layer 3) A sheet-like thermosetting resin composition (colored adhesive layer 3) was prepared in the same manner as in Preparation Example 1, except that the thickness (average thickness) was 80 μm.

[0169] Preparation Example 4 (Preparation of Colored Adhesive Layer 1) 95 parts by mass of butyl acrylate (BA), 5 parts by mass of acrylic acid, 249 parts by mass of ethyl acetate as a solvent, and 0.2 parts by mass of azobisisobutyronitrile were mixed to obtain a monomer composition. The obtained monomer composition was put into a 1 L round-bottom separable flask equipped with a separable cover, a separatory funnel, a thermometer, a nitrogen inlet tube, a Liebig condenser, a vacuum seal, a stirring rod, and a stirring blade, and purged with nitrogen while stirring. Then, while flowing nitrogen and stirring, it was polymerized by holding at 65 °C for 4 hours and then at 75 °C for 2 hours to obtain acrylic polymer A3. To 100 parts by weight of this acrylic polymer A3, 9.75 parts by mass of a black pigment (trade name "ATDN101 Black", manufactured by Dainichi Seika Kogyo Co., Ltd.), 0.4 parts by mass of a crosslinking agent (trade name "Coronate HX", manufactured by Tosoh Corporation), and 0.01 parts by mass of a catalyst (trade name "Narsem Ferric II", manufactured by Nippon Chemical Industry Co., Ltd.) were added to obtain an adhesive composition. The above adhesive composition was applied onto the release-treated surface of a release liner (a release-treated film made of a polyethylene terephthalate film having a thickness of 38 μm and subjected to a silicone release treatment), and then dried at 130 °C for 3 minutes to prepare a sheet-like non-thermosetting resin composition (colored adhesive layer 1) having a thickness (average thickness) of 10 μm.

[0170] Preparation Example 5 (Preparation of Colored Adhesive Layer 2) To 100 parts by weight of the acrylic polymer A3 prepared in Preparation Example 4, 2.5 parts by mass of a black pigment (trade name "ATDN101 Black", manufactured by Dainichi Seika Chemicals Co., Ltd.), 0.4 parts by mass of a crosslinking agent (trade name "Coronate HX", manufactured by Tosoh Corporation), and 0.01 parts by mass of a catalyst (trade name "Narsem Ferric Oxide", manufactured by Nippon Chemical Industry Co., Ltd.) were added to obtain an adhesive composition. The above adhesive composition was applied onto the release-treated surface of a release liner (a release-treated film made of a polyethylene terephthalate film having a thickness of 38 μm and subjected to silicone release treatment), and then dried at 130 °C for 3 minutes to produce a sheet-like non-thermosetting resin composition (colored adhesive layer 2) having a thickness (average thickness) of 40 μm.

[0171] Preparation Example 6 (Preparation of non-colored adhesive layer 1) 60 parts by mass of acrylic polymer A1 (glycidyl methacrylate (GMA): ethyl acrylate (EA): butyl methacrylate (BMA) = 34% by mass: 30% by mass: 36% by mass, weight average molecular weight 60,000), 37 parts by mass of acrylic resin B (trade name "UC-3000", a carboxyl group-containing acrylic resin, manufactured by Toagosei Co., Ltd.), and 3 parts by mass of a silane coupling agent (trade name "KBM-303", manufactured by Shin-Etsu Chemical Co., Ltd.) were dissolved in methyl ethyl ketone to prepare a resin composition solution 5 having a solid content concentration of 50% by mass. The above resin composition solution 5 was applied onto the release-treated surface of a release liner (a release-treated film made of a polyethylene terephthalate film having a thickness of 38 μm and subjected to silicone release treatment), and then dried at 130 °C for 2 minutes to produce a sheet-like thermosetting resin composition (non-colored adhesive layer 1) having a thickness (average thickness) of 150 μm.

[0172] Preparation Example 7 (Preparation of non-colored adhesive layer 2) 68 parts by mass of acrylic polymer A2 (glycidyl methacrylate (GMA): ethyl acrylate (EA): butyl methacrylate (BMA) = 34% by mass: 26% by mass: 40% by mass, weight average molecular weight 100,000), 29 parts by mass of acrylic resin B (trade name "UC-3000", carboxyl group-containing acrylic resin, manufactured by Toagosei Co., Ltd.), and 3 parts by mass of a silane coupling agent (trade name "KBM-303", manufactured by Shin-Etsu Chemical Co., Ltd.) were dissolved in methyl ethyl ketone to prepare a resin composition solution 6 having a solid content concentration of 50% by mass. The resin composition solution 6 was applied onto the release-treated surface of a release liner (a release-treated film made of a polyethylene terephthalate film having a thickness of 38 μm and subjected to a silicone release treatment), and then dried at 130°C for 2 minutes to produce a sheet-like thermosetting resin composition (non-colored adhesive layer 2) having a thickness (average thickness) of 100 μm.

[0173] Preparation Example 8 (Production of non-colored adhesive layer 3) A sheet-like thermosetting resin composition (non-colored adhesive layer 3) was produced in the same manner as in Preparation Example 6 except that the thickness (average thickness) was 10 μm.

[0174] Example 1 The colored adhesive layer 1 obtained in Preparation Example 1 was used as the sealing sheet for Example 1.

[0175] Examples 2 to 4, Comparative Examples 1 to 2 As shown in Table 1, the exposed surfaces of the layers (resin compositions) obtained in each preparation example were bonded to each other to produce a sealing sheet for each example.

[0176] <Evaluation> The following evaluations were performed on the resin compositions and the obtained sealing sheets used in the examples and comparative examples. The results are shown in Table 1.

[0177] (1) Storage modulus G' at 130°C before curing The resin compositions obtained in the preparation examples were laminated to produce a laminate of the resin composition with a thickness of about 300 μm, which was punched into a cylindrical shape with a diameter of φ8 mm to obtain a measurement sample. Using a rheometer (trade name "HAAKEMARSIII Rheometer", manufactured by Thermo SCIENTIFIC), the above measurement sample was measured in shear mode at a frequency of 1 Hz and a heating rate of 5 °C / min in the range of 80 to 160 °C, and the elastic modulus G' at 130 °C was calculated.

[0178] (2) Tensile storage elastic modulus E' at room temperature (25 °C) before curing The resin compositions obtained in the preparation examples were stacked under the condition of 60 °C until the thickness reached 200 μm, and then cut into strips with a width of 10 mm × a length of 40 mm using a cutter knife to obtain measurement samples. Using a solid viscoelasticity measuring device (trade name "RSAIII", manufactured by Rheometric Scientific), the above measurement samples were measured in tensile mode at a frequency of 1 Hz and a chuck distance of 22.5 mm, and the dynamic storage elastic modulus was measured at a heating rate of 5 °C / min in the range of -10 to 250 °C, and the tensile storage elastic modulus E' at 25 °C was calculated.

[0179] (3) Tensile storage elastic modulus E' at room temperature (25 °C) after curing The resin compositions obtained in the preparation examples were stacked under the condition of 60 °C until the thickness reached 200 μm, and then cut into strips with a width of 10 mm × a length of 40 mm using a cutter knife, heated and cured at 150 °C × 1 h to obtain measurement samples (thermally cured except for the colored adhesive layers 1 and 2). Using a solid viscoelasticity measuring device (trade name "RSAIII", manufactured by Rheometric Scientific), the above measurement samples were measured in tensile mode at a frequency of 1 Hz and a chuck distance of 22.5 mm, and the dynamic storage elastic modulus was measured at a heating rate of 5 °C / min in the range of -10 to 250 °C, and the tensile storage elastic modulus E' at 25 °C was calculated.

[0180] (4) Light transmittance after curing The resin composition obtained in the preparation example was heated at 150 °C for 1 hour for curing to obtain a measurement sample. Then, using an ultraviolet-visible-near-infrared spectrophotometer (trade name "V-670DS", manufactured by JASCO Corporation) and an integrating sphere unit, the total light transmittance spectrum in the wavelength range of 300 to 2000 nm was measured, and the transmittance at a wavelength of 600 nm was read from the obtained spectrum.

[0181] (5) Haze value Regarding the resin composition obtained in the preparation example and the encapsulation sheets obtained in the examples and comparative examples, they were heated at 150 °C for 1 hour for curing, and further stored at 125 °C for 1000 hours to obtain measurement samples. Then, they were set in the sample chamber of a haze meter (trade name "NDHG2000", manufactured by Nippon Denshoku Industries Co., Ltd.), and the haze value was measured using a light source D65. Note that the haze of resin compositions and encapsulation sheets with a light transmittance of 0% was not measured.

[0182] (6) Appearance (flatness) The encapsulation sheets obtained in the examples and comparative examples were sealed on a pattern wafer with a height of 10 μm, a length of 30 μm, and a width of 15 μm in a vacuum press device at 130 °C × 0.3 MPa × 600 seconds, and samples after heat curing at 150 °C × 1 h were prepared. The height of the surface undulation of the release liner surface was measured with Dekak, and the difference between the maximum value and the minimum value of the surface undulation was measured. Then, the appearance was evaluated based on the following evaluation criteria. [Evaluation criteria] ◎: The difference between the maximum value and the minimum value of the surface undulation is less than 2 μm 〇: The difference between the maximum value and the minimum value of the surface undulation exceeds 2 μm and is less than 4 μm ×: The difference between the maximum value and the minimum value of the surface undulation exceeds 4 μm

[0183] (7) Luminance A film (product name: "Lumirror S10", thickness: 12 μm) made by Toray Industries, Inc. with a size of 30 mm × 30 mm was placed in the center of a glass plate (product name: "S9112", 76 × 52 mm) made by Matsunami Glass Industry Co., Ltd. Then, the sealing sheets obtained in the examples and comparative examples were stacked on top of it, and sealed at 130 °C × 0.3 MPa × 600 seconds using a vacuum press device. And the luminance was evaluated based on the following evaluation criteria. [Evaluation Criteria] ◎: The transmittance of the film part is 50% or more 〇: The transmittance of the film part is 40% or more and less than 50% △: The transmittance of the film part is 30% or more and less than 40% ×: The transmittance of the film part is less than 30%

[0184] (8) Antireflection property For the sealing sheets obtained in the examples and comparative examples, a sample was prepared by attaching the exposed surface after peeling off the release liner on the optoelectronic device side to an aluminum foil. The obtained sample was installed in "SolidSpec3700" (manufactured by Shimadzu Corporation) with the release liner on the side opposite to the optoelectronic device side facing the light source side, and the reflectance (%) at 280 to 780 nm was measured. And the antireflection property was evaluated based on the following evaluation criteria. [Evaluation Criteria] ◎: The reflectance at 550 nm is 8.5% or less 〇: The reflectance at 550 nm exceeds 8.5% and is 10% or less △: The reflectance at 550 nm exceeds 10% and is 25% or less ×: The reflectance at 550 nm exceeds 25%

[0185] (9) Workability The sealed sample prepared in the above appearance evaluation was diced into a size of 10 mm × 10 mm, and the amount of resin overflow and creep from the wafer edge were evaluated. And the workability was evaluated based on the following evaluation criteria. [Evaluation Criteria] ◎: The amount of resin overflow and creep from the wafer edge are less than 10 μm ×: Resin overhang and creeping from the wafer edge are 10 μm or more

[0186] (10) Chipping The samples used in the above workability evaluation were observed to confirm the amount of chipping, and evaluated based on the following evaluation criteria. [Evaluation Criteria] ◎: The amount of resin chipping from the wafer edge into the resin is less than 10 μm ×: The amount of resin chipping from the wafer edge into the resin is 10 μm or more

[0187] (11) Reliability After the sealed samples prepared in the above appearance evaluation were subjected to 3 cycles of 260 °C × 1 minute, the presence or absence of peeling between the sealing sheet and the wafer was confirmed using SAT. Then, the reliability was evaluated based on the following evaluation criteria. [Evaluation Criteria] ◎: Among those subjected to n9 input, the number of those showing a black shadow in SAT is 0 / 9 〇: Among those subjected to n9 input, the number of those showing a black shadow in SAT is 1 / 9 or more and 3 / 9 or less ×: Among those subjected to n9 input, the number of those showing a black shadow in SAT is 4 / 9 or more

[0188]

Table 1

[0189] As shown in Table 1, when the wafer was sealed with the colored adhesive layer on the wafer side (Examples 1 to 4), the antireflection property and workability were excellent, and no chipping occurred. On the other hand, when a colored pressure-sensitive adhesive layer was used instead of the colored adhesive layer (Comparative Examples 1 and 2), the workability was inferior and chipping occurred.

[0190] Hereinafter, variations of the invention according to the present disclosure will be described. [Appendix 1] A sheet for sealing one or more optical semiconductor elements disposed on a substrate, The sheet includes a sealing resin layer including at least a colored adhesive layer having thermosetting properties, The light semiconductor element encapsulating sheet, wherein the colored adhesive layer contains a colorant and is a layer that contacts the light semiconductor element when the light semiconductor element is encapsulated with the sheet. [Appendix 2] The light semiconductor element encapsulating sheet according to Appendix 1, wherein the thickness of the colored adhesive layer is 5 to 150 μm. [Appendix 3] The light semiconductor element encapsulating sheet according to Appendix 1 or 2, wherein the resin layer for encapsulation includes an uncolored layer located on the side opposite to the side for encapsulating the light semiconductor element with respect to the colored adhesive layer. [Appendix 4] The light semiconductor element encapsulating sheet according to any one of Appendices 1 to 3, wherein the elastic modulus G' of the colored adhesive layer at 130 °C before curing is 0.5 to 10 kPa. [Appendix 5] The light semiconductor element encapsulating sheet according to any one of Appendices 1 to 4, wherein the elastic modulus E' of the colored adhesive layer at room temperature before curing is 500 to 4000 MPa. [Appendix 6] The light semiconductor element encapsulating sheet according to any one of Appendices 1 to 5, wherein the elastic modulus E' of the colored adhesive layer at room temperature after curing is 500 to 4000 MPa. [Appendix 7] The light semiconductor element encapsulating sheet according to any one of Appendices 1 to 6, wherein the light transmittance of the colored adhesive layer at a wavelength of 600 nm after curing is 0 to 80%. [Appendix 8] The light semiconductor element encapsulating sheet according to any one of Appendices 1 to 7, wherein the distance from the light semiconductor element to the colored adhesive layer in a state where the light semiconductor element is encapsulated is 0 to 20 μm. [Appendix 9] The light semiconductor element encapsulating sheet according to any one of Appendices 1 to 8, wherein a layer having antiglare property and / or antireflection property is provided on the surface of the resin layer for encapsulation on the side opposite to the side contacting the light semiconductor element. [Appendix 10] A light semiconductor device including a substrate, a light semiconductor element disposed on the substrate, and the light semiconductor element encapsulating sheet according to any one of Appendices 1 to 9 or a cured product thereof for encapsulating the light semiconductor element.

Explanation of Reference Numerals

[0191] 1 Light semiconductor element encapsulating sheet 2 Resin layer for encapsulation 21 Colored adhesive layer 22 Non-coloring layer 3 Release liner 4 Substrate part 41 Substrate film 42 Functional layer 5 Substrate 6 Optical semiconductor element 7 Hardened sealing layer 71 Colored adhesive layer 72 Non-coloring layer 10,20 Optical semiconductor device

Claims

1. A sheet for encapsulating one or more optical semiconductor elements disposed on a substrate, wherein the sheet comprises an encapsulating resin layer including at least a thermosetting colored adhesive layer, and the colored adhesive layer contains a colorant and is a layer that contacts the optical semiconductor element when the optical semiconductor element is encapsulated with the sheet. An optical semiconductor element encapsulating sheet.

2. The optical semiconductor element encapsulating sheet according to claim 1, wherein the thickness of the colored adhesive layer is 5 to 150 μm.

3. The optical semiconductor element encapsulating sheet according to claim 1 or 2, wherein the encapsulating resin layer includes an uncolored layer located on the side opposite to the side for encapsulating the optical semiconductor element with respect to the colored adhesive layer.

4. The optical semiconductor element encapsulating sheet according to claim 1 or 2, wherein the elastic modulus G' of the colored adhesive layer at 130°C before curing is 0.5 to 10 kPa.

5. The optical semiconductor element encapsulating sheet according to claim 1 or 2, wherein the elastic modulus E' of the colored adhesive layer at room temperature before curing is 500 to 4000 MPa.

6. The optical semiconductor element encapsulating sheet according to claim 1 or 2, wherein the elastic modulus E' of the colored adhesive layer at room temperature after curing is 500 to 4000 MPa.

7. The optical semiconductor element encapsulating sheet according to claim 1 or 2, wherein the light transmittance of the colored adhesive layer at a wavelength of 600 nm after curing is 0 to 80%.

8. The optical semiconductor element encapsulating sheet according to claim 1 or 2, wherein in a state where the optical semiconductor element is encapsulated, the distance from the optical semiconductor element to the colored adhesive layer is 0 to 20 μm.

9. The optical semiconductor element encapsulating sheet according to claim 1 or 2, wherein a layer having antiglare properties and / or antireflection properties is provided on the surface of the encapsulating resin layer on the side opposite to the side contacting the optical semiconductor element.

10. An optical semiconductor device comprising a substrate, an optical semiconductor element disposed on the substrate, and the optical semiconductor element encapsulating sheet according to claim 1 or 2 or a cured product thereof for encapsulating the optical semiconductor element.

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