Optical semiconductor element sealing sheet and optical semiconductor device

Abstract

To provide an optical semiconductor element sealing sheet that excels in anti-reflection properties, light 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 layer 22 and a non-colored adhesive layer 21 having thermosetting properties. The colored layer 22 contains a coloring agent. The non-colored adhesive layer 21 has an elastic modulus G' of 0.5 to 10 kPa at 130°C before curing, 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 optoelectronic device is encapsulated with the sheet.

Background Art

[0002] In self-emitting display devices such as mini / micro light emitting diode displays (Mini / Micro Light Emitting Diode Display), a plurality of LEDs are arranged on a substrate, and those having a structure in which the plurality of LEDs are encapsulated with an encapsulating resin are known. As a method of collectively encapsulating the plurality of LEDs 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 adhesion of the liquid resin 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 an 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, and the appearance of the screen is poor and the design is inferior. For this reason, a technique of using an antireflection layer for preventing reflection by the metal wiring is adopted as an encapsulating material for encapsulating an 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-like manner is being studied.

[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 above-mentioned 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 a sealing member as described in Patent Document 1, the adhesiveness is high, and when a plurality of optoelectronic devices are arranged in a tile-like manner, 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 the sealing sheet in one optical semiconductor device may be damaged. A sealing sheet having excellent adhesion to the optical semiconductor element and the substrate is particularly likely to cause such problems.

[0010] The present invention has been conceived under such circumstances, and its object is to provide an anti-reflection property, a sealing property of an optical semiconductor element, and excellent workability during tiling, and a sealing sheet for an optical semiconductor element in which sheet damage is less likely to occur when separating adjacent optical semiconductor devices.

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 has excellent anti-reflection property, sealing property of an optical semiconductor element, and workability during tiling, and sheet damage is less likely to occur when separating adjacent optical semiconductor devices. 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 colored layer and a non-colored adhesive layer having thermosetting properties, The colored layer contains a colorant, The non-colored adhesive layer provides a sealing sheet for an optical semiconductor element, which has an elastic modulus G' of 0.5 to 10 kPa at 130°C before curing and is a layer that contacts the optical semiconductor element when the optical semiconductor element is sealed.

[0013] The thickness of the non-colored adhesive layer is preferably 5 to 75 μm.

[0014] The room temperature elastic modulus E' of the non-colored adhesive layer before curing is preferably 500 to 4000 MPa.

[0015] The room temperature elastic modulus E' of the non-colored adhesive layer after curing is preferably 500 to 4000 MPa.

[0016] The light transmittance of the non-colored adhesive layer at a wavelength of 600 nm after curing is preferably more than 80%.

[0017] In the state where the light semiconductor element is encapsulated, the distance from the light semiconductor element to the non-colored adhesive layer in the sheet for encapsulating the light semiconductor element is preferably 0 to 20 μm.

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

[0019] The colored layer is a colored adhesive layer having thermosetting properties. The ratio [room temperature elastic modulus E' after curing / room temperature elastic modulus E' before curing] of the room temperature elastic modulus E' after curing to the room temperature elastic modulus E' before curing of the colored adhesive layer is preferably 0.6 to 2.0.

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

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

Advantages of the Invention

[0022] According to the sheet for encapsulating an optical semiconductor device of the present invention, it is excellent in antireflectivity, the encapsulation property of the optical semiconductor device, and the workability during tiling, and it is difficult for the sheet to be damaged when separating adjacent optical semiconductor devices from each other. 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 any 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

Embodiments for Carrying Out the Invention

[0024] [Sheet for Encapsulating Optical Semiconductor Device] The sheet for encapsulating an optical semiconductor device of the present invention includes at least an encapsulating resin layer including a colored layer and a non-colored adhesive layer. In this specification, the sheet for encapsulating an optical semiconductor device means a sheet for encapsulating one or more optical semiconductor devices arranged 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 that can embed at least a part of the optical semiconductor device or follow and cover it with the above encapsulating resin layer.

[0025] <Encapsulating Resin Layer> The resin layer for sealing includes at least the colored layer and the non-colored adhesive layer. The resin layer for sealing may include other layers other than the colored layer and the non-colored adhesive layer. Examples of the other layers include a non-colored pressure-sensitive adhesive layer. Each layer (colored layer and non-colored adhesive layer) constituting the resin layer for sealing may be a single layer within the resin layer for sealing, or may be a multi-layer having the same or different compositions. When a multi-layer of a colored layer or a non-colored adhesive layer is included, the multi-layers may be laminated in contact with each other, or may be laminated separately (for example, two non-colored adhesive layers are laminated via one colored layer).

[0026] In the resin layer for sealing, the layer that contacts the optical semiconductor element when the optical semiconductor element is sealed (that is, the layer closest to the optical semiconductor element side in the resin layer for sealing) is a non-colored adhesive layer having thermosetting properties. When the layer in contact with the optical semiconductor element is a thermosetting non-colored adhesive layer, it has excellent workability before thermosetting and exhibits adhesiveness to the optical semiconductor element and the substrate after thermosetting. Further, the colored layer is preferably a colored adhesive layer (thermosetting adhesive layer) having thermosetting properties. It is preferable that all the colored layers and non-colored layers in the resin layer for sealing are thermosetting adhesive layers. In this specification, the "adhesive layer", unlike a pressure-sensitive adhesive layer, does not have tackiness or adhesiveness on the surface, or has extremely low tackiness or adhesiveness, and has curability and adheres to the adherend by curing.

[0027] (Non-colored adhesive layer) The non-colored adhesive layer is a layer different from the colored layer and is not intended to prevent reflection of light by metal wiring or the like. The non-colored adhesive layer may be a colorless layer or may be slightly colored. Further, the non-colored adhesive 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 adhesive layer may be transparent or non-transparent. The non-colored adhesive layer is preferably a resin layer composed of resin.

[0028] The non-colored adhesive layer is a layer located at a position where it contacts the optical semiconductor element when the optical semiconductor element is encapsulated with the above-mentioned sheet for encapsulating an optical semiconductor element. When the above-mentioned encapsulating resin layer contains multiple non-colored layers, at least one non-colored adhesive layer having thermosetting properties may be located at a position where it contacts the optical semiconductor element. The non-colored adhesive layer that contacts the optical semiconductor element may be the above-mentioned diffusion functional layer or the above-mentioned non-diffusion functional layer.

[0029] The content ratio of the colorant in the above-mentioned non-colored adhesive 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 adhesive layer.

[0030] The total light transmittance of the above-mentioned non-colored adhesive 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. Also, the upper limit value of the total light transmittance of the above-mentioned non-colored adhesive layer is not particularly limited, and it may be less than 100%, or may be 99.9% or less, or 99% or less.

[0031] The total light transmittance of the above-mentioned non-colored adhesive layer is a value for a single layer, can be measured by the method defined in JIS K7136 and JIS K7361-1, and can be controlled by the type and thickness of the non-colored adhesive layer, etc.

[0032] The above diffusion functional layer is a layer for the purpose of diffusing light. When the above resin layer for sealing has the above 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 above diffusion functional layer is preferably a resin layer composed of resin. The above diffusion functional layer preferably contains, although not limited to, light-diffusing fine particles. That is, the above diffusion functional layer preferably contains light-diffusing fine particles dispersed in the resin layer. Only one kind of the above light-diffusing fine particles may be used, or two or more kinds may be used.

[0033] The above 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 resins (including polymethacrylate resins such as polymethyl methacrylate), polystyrene resin, polyurethane resin, melamine resin, polyethylene resin, epoxy resin, etc.

[0034] As the above polymer fine particles, fine particles composed of silicone resin are preferable. Also, as the above inorganic fine particles, fine particles composed of metal oxides are preferable. As the above 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 above diffusion functional layer is more excellent, and luminance unevenness is more suppressed.

[0035] The shape of the above light-diffusing fine particles is not particularly limited, and may be, for example, spherical, flat, or irregular.

[0036] From the perspective of imparting appropriate light diffusion 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. Also, from the perspective 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.

[0037] The refractive index of the above light-diffusing fine particles is preferably 1.2 to 5, more preferably 1.25 to 4.5, still more preferably 1.3 to 4, and particularly preferably 1.35 to 3.

[0038] From the perspective 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. Also, from the perspective 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.

[0039] From the perspective of imparting appropriate light diffusion performance to the sheet for encapsulating the optical semiconductor element, the content of the above 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 with respect to 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 with respect to 100 parts by mass of the resin constituting the diffusion functional layer.

[0040] The haze value (thickness: 50 μm) of the above diffusion functional layer is not particularly limited. However, 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, particularly preferably 60% or more, and may be 70% or more, 80% or more, 90% or more, 95% or more, 97% or more. Furthermore, those around 99.9% are preferable because of their excellent luminance unevenness improvement effect. The upper limit of the haze value of the above diffusion functional layer is not particularly limited, that is, it may be 100%. The above haze value may be any value before or after curing, but is preferably the value after curing.

[0041] The total light transmittance of the above diffusion functional layer is not particularly limited. However, from the perspective of ensuring luminance, it is preferably 40% or more, more preferably 60% or more, still more preferably 70% or more, particularly preferably 80% or more. The upper limit value of the total light transmittance of the above diffusion functional layer is not particularly limited, and it may be less than 100%, may be 99.9% or less, or may be 99% or less.

[0042] The haze value and the total light transmittance of the above diffusion 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 diffusion functional layer, the type and blending amount of the light-diffusing fine particles, etc.

[0043] The haze value (thickness: 50 μm) of the above non-diffusion functional layer is not particularly limited. However, 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 be 0.5% or less. The lower limit of the haze value of the above non-diffusion functional layer is not particularly limited. The above haze value may be any value before or after curing, but is preferably the value after curing.

[0044] The total light transmittance of the non-diffusing functional layer is not particularly limited, but from the perspective of ensuring brightness, it is preferably 60% or more, more preferably 70% or more, still more preferably 80% or more, and particularly preferably 90% or more. Also, the upper limit value of the total light transmittance of the non-diffusing functional layer is not particularly limited, but it may be less than 100%, and may be 99.9% or less, or 99% or less.

[0045] 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.

[0046] From the perspective of making the brightness of the image display device excellent, 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.

[0047] The elastic modulus G' of the non-colored adhesive layer at 130°C before curing is 0.5 to 10 kPa, preferably 0.6 to 9 kPa, more preferably 0.8 to 8 kPa. When the elastic modulus G' is 0.5 kPa or more, the workability is excellent. When the elastic modulus G' is 10 kPa or less, the embedding property or followability of the optical semiconductor element is more excellent, and when it is 9 kPa or less, the generation of voids during thermosetting is more suppressed and the reliability is more excellent.

[0048] The elastic modulus E' of the non-colored adhesive layer at room temperature (25°C) before curing is preferably 500 to 4000 MPa, more preferably 550 to 3000 MPa, still more preferably 600 to 2000 MPa. When the elastic modulus E' is within the above range, the stickiness is further reduced and the workability is more excellent.

[0049] The room temperature elastic modulus E’ of the non-colored adhesive layer after curing is preferably 500 to 4000 MPa, more preferably 600 to 3000 MPa, and even more preferably 700 to 2000 MPa. When the elastic modulus E’ is within the above range, stickiness is further reduced and chipping is less likely to occur.

[0050] The ratio [room temperature elastic modulus E’ after curing / room temperature elastic modulus E’ before curing] of the non-colored adhesive layer is preferably 0.6 to 3.1, more preferably 0.8 to 2.5, and even more preferably 0.9 to 2. When the ratio is within the above range, the change in hardness before and after curing is small, and workability and scratch resistance are more excellent.

[0051] The light transmittance of the non-colored adhesive layer at a wavelength of 600 nm after curing (thickness 50 μm) is not particularly limited, but from the viewpoint of further improving the brightness 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.

[0052] The thickness of the non-colored adhesive layer (the thickness of the non-colored adhesive layer in contact with the optical semiconductor element) is preferably 5 to 75 μm, more preferably 7 to 70 μm, and even more preferably 9 to 60 μm. When the thickness is 5 μm or more, the sealing property of the optical semiconductor element is more excellent. When the thickness is 75 μm or less, the brightness of the optical semiconductor device is more excellent.

[0053] (Colored layer) The colored layer in the encapsulating resin layer is a layer for the purpose of preventing light reflection by metal wiring or the like provided on the substrate in the image display device. The colored layer contains at least a colorant. The colored layer is preferably a resin layer composed of a resin, and more preferably a thermosetting adhesive layer as described above.

[0054] The above coloring agent may be a dye or a pigment as long as it can be dissolved or dispersed in the above coloring layer. Since a low haze can be achieved even with a small amount of addition and it is easy to distribute uniformly without sedimentation like a pigment, a dye is preferred. Also, since high color developability can be achieved even with a small amount of addition, a pigment is also preferred. When using a pigment as the coloring agent, it is preferably one with low conductivity or no conductivity. The above coloring agent may be used alone or in combination of two or more.

[0055] 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. Also, a coloring agent that functions as a black coloring agent by combining coloring agents that exhibit colors other than black may be used.

[0056] When the above coloring layer is a radiation-curable resin layer, the above coloring agent preferably absorbs visible light and has permeability to light with a wavelength at which the above radiation-curable resin layer can be cured.

[0057] 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 layer is preferably 0.03% by mass or more, more preferably 0.1% by mass or more, based on the total amount (100% by mass) of the coloring layer. Also, the content ratio of the above coloring agent is, for example, 2% by mass or less, preferably 1% by mass or less, more preferably 0.6% 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 obtained by dissolving or dispersing it in an appropriate solvent.

[0058] The elastic modulus G' of the above coloring layer before curing at 130°C is preferably 0.5 to 10 kPa, more preferably 2 to 9.5 kPa, and even more preferably 4 to 9.2 kPa. When the elastic modulus G' is within the above range, the embedding property or followability of the optical semiconductor element is excellent.

[0059] The elastic modulus E' of the above coloring layer at room temperature (25°C) before curing is preferably 500 to 4000 MPa, more preferably 600 to 2500 MPa, and even more preferably 700 to 1000 MPa. When the elastic modulus E' is within the above range, stickiness is further reduced and workability is excellent.

[0060] The elastic modulus E' of the above coloring layer (colored adhesive layer) at room temperature after curing is preferably 500 to 4000 MPa, more preferably 600 to 2500 MPa, and even more preferably 700 to 1000 MPa. When the elastic modulus E' is within the above range, stickiness is further reduced and chipping is less likely to occur.

[0061] The ratio [elastic modulus E' at room temperature after curing / elastic modulus E' at room temperature before curing] of the above coloring layer (colored adhesive layer) is preferably 0.6 to 2.0, more preferably 0.8 to 1.5, and even more preferably 0.9 to 1.2. When the ratio is within the above range, the change in hardness before and after curing is small, and workability and scratch resistance are excellent.

[0062] The light transmittance of the above coloring layer (colored adhesive layer) at a wavelength of 600 nm after curing (thickness 50 μm) is not particularly limited, but from the viewpoint of further improving the antireflection function and contrast of metal wiring etc. in the optical semiconductor device, it is preferably 80% or less, more preferably 60% or less, even more preferably 40% or less, and particularly preferably 30% or less. Also, the 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, even more preferably 1.5% or more, and particularly preferably 2% or more, and it may be 2.5% or more, or 3% or more.

[0063] The haze value (thickness: 50 μm) of the above-mentioned colored layer is preferably 50% or less, more preferably 40% or less, still more preferably 30% or less, and particularly preferably 20% or less, from the viewpoint of ensuring the front luminance and visibility when the optical semiconductor element is encapsulated. Also, the haze value of the above-mentioned colored 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. When the above-mentioned colored layer has curability, the haze value may be any value before or after curing, but is preferably the value after curing.

[0064] The total light transmittance of the above-mentioned colored layer is not particularly limited, but is preferably 80% or less, more preferably 60% or less, still more preferably 40% or less, and particularly preferably 30% or less, from the viewpoint of exhibiting appropriate light-shielding properties. Also, the total light transmittance of the above-mentioned colored 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 may be 2.5% or more, or 3% or more, from the viewpoint of ensuring the luminance when the optical semiconductor element is encapsulated.

[0065] The haze value and total light transmittance of the above-mentioned colored layer are each the value of a single layer, 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.

[0066] The thickness of the above-mentioned colored layer (the thickness of the above-mentioned colored layer closest to the optical semiconductor element side in the above-mentioned resin layer for encapsulation) is preferably 10 to 200 μm, more preferably 20 to 150 μm, and still more preferably 30 to 100 μm. When the above-mentioned thickness is 10 μm or more, the antireflection property is more excellent. When the above-mentioned thickness is 150 μm or less, the luminance of the optical semiconductor device is more excellent.

[0067] (Resin layer) When the colored layer and the non-colored adhesive layer are the resin layer, examples of the resin constituting the resin 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, and the like. Only one kind of the resin may be used, or two or more kinds may be used. Among them, acrylic resins are preferred. The resins constituting each layer of the resin layer for sealing may be the same as or different from each other.

[0068] The 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 kind of the acrylic resin may be used, or two or more kinds may be used.

[0069] The acrylic resin preferably contains the largest mass ratio of the structural unit derived from the (meth)acrylate ester. In this specification, "(meth)acrylic" represents "acrylic" and / or "methacrylic" (either one or both of "acrylic" and "methacrylic"), and the same applies to others.

[0070] The resin layer preferably contains a thermosetting resin. As the thermosetting resin, known or commonly used resins having thermosetting properties can be used, such as resins having thermosetting functional groups. Among them, as the thermosetting resin, an acrylic resin having a thermosetting functional group (a thermosetting functional group-containing acrylic resin) is preferred.

[0071] 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.

[0072] 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.

[0073] Examples of the above-mentioned glycidyl group-containing (meth)acrylic acid ester include glycidyl (meth)acrylate, methyl glycidyl (meth)acrylate, and the like.

[0074] 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.

[0075] Examples of the 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, and (4-hydroxymethylcyclohexyl)methyl (meth)acrylate.

[0076] Among the 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 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 resin layer hardens. Therefore, the resin layer has appropriate flexibility after thermosetting and is excellent in the sealing property of the optical semiconductor element.

[0077] The content ratio of the structural unit derived from the 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 resin layer. When the content ratio is within the above range, the resin layer has appropriate flexibility after thermosetting and is excellent in the sealing property of the optical semiconductor element.

[0078] The thermosetting functional group-containing acrylic resin may contain a structural unit derived from other monomers other than the thermosetting functional group-containing monomer. Examples of the other monomers include other (meth)acrylic acid esters other than the thermosetting functional group-containing acrylic monomers. Only one kind of the other monomers may be used, or two or more kinds may be used.

[0079] 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.

[0080] 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, and the like.

[0081] 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, the flexibility of the above thermosetting group-containing acrylic resin during thermosetting is more likely to be appropriate, and the embedding property is further improved.

[0082] Examples of the (meth)acrylic acid ester having an 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, 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, 2-ethyl-2-adamantyl (meth)acrylate, etc.

[0083] Examples of the (meth)acrylic acid ester having an aromatic hydrocarbon group include phenyl (meth)acrylate, benzyl (meth)acrylate, etc.

[0084] Examples of the hydrocarbon group-containing (meth)acrylic acid ester having an alkoxy group include those obtained by substituting one or more hydrogen atoms in the hydrocarbon group of the above hydrocarbon group-containing (meth)acrylic acid ester with an alkoxy group, such as 2-methoxymethyl ester, 2-methoxyethyl ester, 2-methoxybutyl ester of (meth)acrylic acid, etc.

[0085] As the above-mentioned other monomer components, polar group-containing monomers such as sulfonic acid group-containing monomers, phosphoric acid group-containing monomers, and nitrogen atom-containing monomers can be further mentioned. Examples of the above-mentioned 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 above-mentioned phosphoric acid group-containing monomers include 2-hydroxyethyl acryloyl phosphate and the like. Examples of the above-mentioned 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.

[0086] 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 above-mentioned polyfunctional (meth)acrylates 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. The above-mentioned polyfunctional (meth)acrylates may be used alone or in combination of two or more.

[0087] The above-mentioned acrylic resin containing a thermosetting functional group is obtained by polymerizing the above-mentioned 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 acrylic resin obtained may be any of a random copolymer, a block copolymer, a graft copolymer, and the like.

[0088] From the viewpoint of having a certain degree of hardness after curing of the resin layer and reducing the adhesion between the side surfaces of the optical semiconductor device, the weight average molecular weight of the above-mentioned acrylic resin containing an epoxy group 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.

[0089] The content ratio of the above-mentioned acrylic resin containing an epoxy group is preferably 40% by mass or more, more preferably 50% by mass or more, and still more preferably 60% by mass or more with respect to the total amount (100% by mass) of the resin in the resin layer. When the content ratio is 40% by mass or more, the embedding property of the optical semiconductor element is excellent. The content ratio is 100% by mass or less, preferably 94% by mass or less, and more preferably 92% by mass or less.

[0090] The above-mentioned resin 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 second functional group is also a thermosetting functional group. In this case, the curing of the resin layer is further promoted by the reaction between the first functional group and the second functional group during heating of the resin layer.

[0091] 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.

[0092] 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.

[0093] When the epoxy group-containing acrylic resin is included, it is preferable that the resin layer includes, as the component having the second functional group, a component having a functional group reactive with an epoxy group. Examples of the functional group reactive with an 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 an epoxy group, a silanol group is preferable as the hydroxy group.

[0094] 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. Also, the surface scratch resistance is even more excellent.

[0095] The above carboxy group-containing acrylic resin preferably contains a structural unit derived from a carboxy group-containing monomer, and more preferably contains a structural unit derived from a carboxy group-containing acrylic monomer. Examples of the above 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.

[0096] The content ratio of the structural unit derived from the above 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 above carboxy group-containing acrylic resin. When the above content ratio is within the above range, the above resin layer has appropriate flexibility after thermosetting and is excellent in the sealing property of the optical semiconductor element.

[0097] The above carboxy group-containing acrylic resin may contain a structural unit derived from other monomers other than the above carboxy group-containing monomer. Examples of the above other monomers include other (meth)acrylic acid 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.

[0098] Examples of the above other (meth)acrylic acid esters include hydrocarbon group-containing (meth)acrylic acid esters which may have the above alkoxy group. Among the (meth)acrylic acid alkyl esters in the hydrocarbon group-containing (meth)acrylic acid ester which may have the above 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, more preferably 1 to 10, still more preferably 1 to 8) are preferable. 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.

[0099] In order to appropriately exhibit basic properties such as adhesion to the above-mentioned optical semiconductor element in the resin layer, the ratio of the hydrocarbon group-containing (meth)acrylate ester which may have an alkoxy group to the total amount (100% by mass) of all the constituent units of the above-mentioned carboxyl group-containing acrylic resin is preferably 50 to 95% by mass, more preferably 60 to 90% by mass.

[0100] The weight average molecular weight of the above-mentioned carboxyl group-containing acrylic resin is preferably 1000 to 200000, more preferably 3000 to 100000. 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 conversion.

[0101] When the above-mentioned carboxyl group-containing acrylic resin is included, the content ratio of the above-mentioned carboxyl 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 with respect to the total amount (100% by mass) of the resin in the above-mentioned resin layer. When the content ratio is within the above range, the thermosetting property of the resin layer is more excellent. Also, the surface scratch resistance is more excellent.

[0102] The above-mentioned resin layer may contain other components other than the above-mentioned each component within a range not impairing the effects of the present invention. 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, softening agents, surfactants, antistatic agents, surface lubricants, leveling agents, light stabilizers, ultraviolet absorbers, polymerization inhibitors, granular substances, foil-like substances, and the like. Each of the above-mentioned other components may be used alone or in combination of two or more.

[0103] The content ratio of the resin in the resin layer is preferably 60% by mass or more, more preferably 70% by mass or more, and still more preferably 80% by mass or more, based on the total amount (100% by mass) of the resin layer. The content ratio is 100% by mass or less, may be 99.99% by mass or less, and may be 99% by mass or less, or 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.

[0104] The resin layer can be formed, for example, using a thermosetting resin composition (adhesive composition). The resin layer can be produced, for example, by applying the adhesive composition to the release-treated surface of the release liner or the 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.

[0105] Examples of the laminated structure of the resin layer for sealing include [diffusion functional layer / coloring layer], [non-diffusion functional layer / coloring layer], [diffusion functional layer / coloring layer / non-diffusion functional layer], [non-diffusion functional layer / coloring layer / diffusion functional layer], [diffusion functional layer / coloring layer / diffusion functional layer], [non-diffusion functional layer / coloring layer / non-diffusion functional layer] (in the above order from the light semiconductor element side).

[0106] (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 side contacting the optical semiconductor device is the side contacting the base material portion. When 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, thereby 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. Further, by forming an anti-glare layer or an antireflection layer, which will be described later, on the base material portion, the optical semiconductor device can be imparted with anti-glare properties and antireflection properties. Further, in the sheet for encapsulating an optical semiconductor device, it serves as a support for the encapsulating resin layer, and by including the base material portion, the handleability of the sheet for encapsulating an optical semiconductor device is excellent. Note that the base material portion does not necessarily have to be provided.

[0107] The base material portion may be a single layer or a multi-layer in which the composition, thickness, etc. are the same or different. When the base material portion is a multi-layer, each layer may be bonded together by another layer such as an adhesive layer. Note that the base material layer used for the base material portion is a portion that is pasted 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 (pasted) or a surface protection film that only protects the surface of the base material portion is not included in the "base material portion".

[0108] 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 polymer, ethylene-butene copolymer, ethylene-hexene copolymer; polyurethane; polyesters such as polyethylene terephthalate (PET), polyethylene naphthalate, polybutylene terephthalate (PBT); polycarbonate; polyimide resin; polyetheretherketone; polyetherimide; 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. Only one kind of the above resin may be used, or two or more kinds may be used. The base material layer may be various optical films such as an antireflection (AR) film, a polarizing plate, and a retardation plate.

[0109] 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.

[0110] 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, for example, 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) 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.

[0111] From the viewpoint of excellent function 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.

[0112] <Sheet for Sealing Optical Semiconductor Element> The sheet for sealing an optical semiconductor element may be provided with 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 carried out by known or conventional methods. 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.

[0113] The haze value of the sheet for encapsulating the optical semiconductor device is not particularly limited, but from the viewpoint of more excellent suppression effect of luminance unevenness and design property, it is preferably 0.5% or more, more preferably 1% or more, still more preferably 3% or more. The upper limit of the haze value is not particularly limited and may be 100%, or may be 80%, 60%, or 40%. The haze value may be any value before or after curing, but is preferably the value after curing.

[0114] The total light transmittance of the sheet for encapsulating the optical semiconductor device is not particularly limited, but from the viewpoint of antireflection function such as metal wiring and further improving contrast, it is preferably 40% or less, more preferably 30% or less, still more preferably 20% or less. Also, from the viewpoint of ensuring luminance, the total light transmittance is preferably 0.5% or more.

[0115] 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 part.

[0116] 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 non-colored adhesive layer (the non-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.

[0117] 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 viewpoint 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.

[0118] 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.

[0119] [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 non-coloring adhesive layer (the non-coloring 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 part, 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 does not necessarily have to be provided.

[0120] 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.

[0121] Examples of the above-mentioned release liner include polyethylene terephthalate (PET) film, polyethylene film, polypropylene film, plastic films and papers surface-coated with a release agent such as a fluorine-based release agent or a long-chain alkyl acrylate-based release agent.

[0122] 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.

[0123] FIG. 1 is a cross-sectional view showing an embodiment of a sheet for encapsulating an optical semiconductor device of the present invention. As shown in FIG. 1, 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.

[0124] In the sheet 1 for encapsulating an optical semiconductor device shown in FIG. 1, the resin layer 2 for encapsulation is formed from a laminate of a non-colored adhesive layer 21 and a colored layer 22. The colored layer 22 is directly laminated on the non-colored adhesive layer 21. A release liner 3 is attached to the non-colored adhesive layer 21, and the base material portion 4 is attached to the colored layer 22. The non-colored adhesive layer 21 is a thermosetting adhesive layer. The colored layer 22 is preferably a thermosetting adhesive layer.

[0125] In FIG. 1, 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 that can impart various functions for encapsulating the optical semiconductor device. Examples of the functional layer include a layer containing a surface treatment layer. By having such a configuration, the sheet for encapsulating an optical semiconductor device in which a functional layer including a surface treatment layer is laminated has excellent light diffusibility and excellent light extraction efficiency. Examples of the surface treatment layer include an antiglare treatment layer (antifogging treatment layer), an antireflection treatment layer, and a hard coat treatment layer. 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 provided with the resin layer for encapsulation of the base material portion.

[0126] [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, in the sheet 1 for encapsulating an optical semiconductor element shown in FIG. 1, an uncolored adhesive layer 21 and a colored layer 22 are separately produced, each sandwiched between the release surfaces of two release liners. One of the release liners bonded to the uncolored adhesive layer 21 is the release liner 3. Next, one of the release liners attached to the colored layer 22 is peeled off to expose the surface of the colored layer 22, and the exposed surface is bonded to the base material portion 4. Then, one of the release liners attached to the uncolored adhesive layer 21 (the release liner other than the release liner 3) is peeled off, and the release liner on the surface of the colored layer 22 is peeled off to expose the surface of the colored layer 22, and the exposed surface of the uncolored adhesive layer 21 is bonded to the exposed surface of the colored layer 22. The lamination of various layers can be performed using known rollers or laminators. In this way, the sheet 1 for encapsulating an optical semiconductor element shown in FIG. 1, in which the colored layer 22, the uncolored adhesive layer 21, and the release liner 3 are laminated in this order on the base material portion 4, can be produced.

[0127] [Optical semiconductor device] An optical semiconductor device such as an image display device can be manufactured using the above sheet for encapsulating an optical semiconductor element. The optical semiconductor device manufactured using the above sheet for encapsulating an optical semiconductor element includes a substrate, an optical semiconductor element disposed on the substrate, and the above 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 uncolored adhesive layer 21 (or further the colored layer 22) included in the sheet for encapsulating an optical semiconductor element. Specifically, it includes a cured encapsulation layer obtained by thermally curing the uncolored adhesive layer 21.

[0128] Examples of the above 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.

[0129] In the above-described optical semiconductor device, the sheet for encapsulating the optical semiconductor element is excellent in followability to unevenness when the optical semiconductor element is a convex portion and the gaps between the plurality of optical semiconductor elements are concave portions, and is excellent in followability and embedability of the optical semiconductor element. Therefore, it is preferable to encapsulate the plurality of optical semiconductor elements together.

[0130] FIG. 2 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. 2 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 the optical semiconductor element. The cured product of the sheet for encapsulating the optical semiconductor element is formed by peeling the release liner 3 from the sheet 1 for encapsulating the optical semiconductor element and thermally curing the non-colored adhesive layer 21 to form a cured encapsulation layer 7. For example, the cured encapsulation layer 7 is composed of a non-colored adhesive layer 71 formed by thermally curing the non-colored adhesive layer 21 and a colored layer 72 formed by thermally curing the colored layer 22. The plurality of optical semiconductor elements 6 are encapsulated together 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 adheres closely to the optical semiconductor element 6 and the substrate 5, embedding the optical semiconductor element 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.

[0131] In the optical semiconductor device 10 shown in FIG. 2, the optical semiconductor element 6 is completely embedded and encapsulated in the non-colored adhesive layer 71 and is indirectly encapsulated by the colored layer 72. That is, the optical semiconductor element 6 is encapsulated by the cured encapsulation layer 7 composed of a laminate of the non-colored adhesive layer 71 and the colored layer 72. The above-described optical semiconductor device is not limited to such a mode. For example, as shown in FIG. 3, the optical semiconductor element 6 may be a mode in which it is completely embedded and encapsulated in the non-colored adhesive layer 71 and the colored layer 72.

[0132] As described above, the above-mentioned optical semiconductor device encapsulates the optical semiconductor element with a cured encapsulation layer. The above-mentioned thermosetting adhesive layer has sufficient flexibility before thermosetting, so it has excellent unevenness followability, fully embeds the optical semiconductor element, and fixes the optical semiconductor element after thermosetting. Therefore, the optical semiconductor element is in close contact with the cured encapsulation layer, and the encapsulation property of the optical semiconductor element is excellent. In addition, since the side surface of the thermosetting 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 defects and adhesion of the sheet of adjacent optical semiconductor devices are unlikely to occur.

[0133] 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.

[0134] Fig. 4 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. 4 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 defects on the side surface of the cured encapsulation layer 7 and adhesion of the resin lacking on the side surface of the cured encapsulation layer from one adjacent optical semiconductor device to the other are unlikely to occur.

[0135] The above image display device preferably includes a self-emitting display device. Further, an image display device can be formed by combining the self-emitting display device and, if necessary, a display panel. In this case, the optical semiconductor element is an LED element. Examples of the self-emitting display device include an LED display, a backlight, or an organic electroluminescence (organic EL) display device. The backlight is preferably a full array direct-lit backlight. The backlight includes, for example, at least a part of a laminate including the substrate and a plurality of optical semiconductor elements disposed on the substrate as a constituent member. For example, in the self-emitting display device, a metal wiring layer for sending a light emission control signal to each LED element is laminated on the 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.

[0136] The sheet for encapsulating the optical semiconductor element can be used for an optical semiconductor device that is used in a bent state, for example, an image display device that can be bent (flexible display) (particularly, an image display device that can be folded (foldable display)). Specifically, it can be used for a foldable backlight and a foldable self-emitting display device.

[0137] Since the sheet for encapsulating the optical semiconductor element is excellent in the 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.

[0138] [Manufacturing Method of Optical Semiconductor Device] The above-mentioned optical semiconductor device can be manufactured, for example, by a manufacturing method including a step of bonding the above-mentioned sheet for sealing the optical semiconductor element to the above-mentioned optical semiconductor element provided on the above-mentioned substrate to seal the above-mentioned optical semiconductor element with the above-mentioned sealing resin layer (sealing step), and a step of heating a laminate including the above-mentioned substrate, the above-mentioned optical semiconductor element disposed on the above-mentioned substrate, and the above-mentioned sheet for sealing the above-mentioned optical semiconductor element to cure the above-mentioned non-colored adhesive layer to obtain the above-mentioned cured product (heating step). The above-mentioned cured product is a cured product obtained by thermally curing the above-mentioned non-adhesive colored layer, specifically, it includes a cured sealing layer obtained by thermally curing the above-mentioned non-colored adhesive layer.

[0139] The above-mentioned manufacturing method may further include a step of dicing the above-mentioned laminate that has undergone the above-mentioned heating step to obtain an optical semiconductor device (dicing step). Further, the above-mentioned manufacturing method may further include a tiling step of arranging a plurality of optical semiconductor devices obtained in the above-mentioned dicing step in contact with each other in the planar direction. Hereinafter, the manufacturing method of the optical semiconductor device 10 shown in FIG. 2 and the optical semiconductor device 20 shown in FIG. 4 will be described with appropriate reference.

[0140] (Sealing step) In a method of manufacturing an optical semiconductor device using the sheet for sealing an optical semiconductor element, the method includes a sealing step of bonding the sheet for sealing an optical semiconductor element to a substrate on which the optical semiconductor element is disposed and sealing the optical semiconductor element with a resin layer for sealing. Specifically, in the sealing step, first, a release liner is peeled off from the sheet for sealing an optical semiconductor element to expose the resin layer for sealing. Then, the exposed surface of the sheet for sealing an optical semiconductor element is bonded to the surface of the substrate of the 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 on which the optical semiconductor element is disposed. When the laminate includes a plurality of optical semiconductor elements, the resin layer for sealing is further arranged to fill the gaps between the plurality of optical semiconductor elements, and the plurality of optical semiconductor elements are sealed together. Specifically, the non-colored adhesive layer 21 exposed by peeling off the release liner 3 from the sheet 1 for sealing an optical semiconductor element shown in FIG. 1 is arranged to face the surface of the substrate 5 on which the optical semiconductor element 6 is disposed, and the sheet 1 for sealing 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 resin layer 2 for sealing.

[0141] The temperature during the bonding is, for example, in the range from room temperature to 150°C. Also, during the bonding, reduced pressure or increased pressure may be applied. By applying reduced pressure or increased pressure, it is possible to suppress the formation of voids between the resin layer for sealing and the substrate or the optical semiconductor element. Further, in the sealing step, it is preferable to bond the sheet for sealing 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. 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.

[0142] (Heating step) In the above heating step, the laminate (for example, the laminate obtained in the above sealing step) 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 non-coloring adhesive layer and, if necessary, the coloring layer. In the above heating step, specifically, as shown in FIG. 2, the non-coloring 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 above heating is, for example, in the range of 80 to 200 ° C, and the heating time is, for example, 1 minute to 24 hours.

[0143] (Dicing step) In the above dicing step, the laminate that has undergone the above heating step is diced. Here, in the laminate subjected to the dicing step, the cured product of the sheet for sealing the optical semiconductor element and the substrate 5 extend wider in the planar direction than the finally obtained optical semiconductor device 10. Then, in the above dicing step, 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 above 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. 2 can be manufactured.

[0144] (Tiling step) In the above tiling step, the plurality of optical semiconductor devices obtained in the above dicing step are tiled by arranging them in contact with each other in the planar direction. In this way, for example, the optical semiconductor device 20 (for example, one large image display device) shown in FIG. 4 can be manufactured. The optical semiconductor device obtained by tiling has excellent sealing properties of the optical semiconductor element, and when separating adjacent optical semiconductor devices, sheet defects and adhesion of the sheet of adjacent optical semiconductor devices are less likely to occur.

Example

[0145] 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.

[0146] Preparation Example 1 (Preparation of the 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", 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 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 (non-colored adhesive layer 1) having a thickness (average thickness) of 10 μm.

[0147] Preparation Example 2 (Preparation of the non-colored adhesive layer 2) 91 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), 6 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 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 (non-colored adhesive layer 2) having a thickness (average thickness) of 50 μm.

[0148] Preparation Example 3 (Preparation of the non-colored adhesive layer 3) 95 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), 2 parts by mass of acrylic resin B (trade name "UC-3000", carboxy 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 3 having a solid content concentration of 50% by mass. The resin composition solution 3 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 3) having a thickness (average thickness) of 50 μm.

[0149] Preparation Example 4 (Preparation of non-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 stirring blades, and nitrogen substitution was carried out while stirring. Then, while flowing nitrogen and stirring, it was held at 65°C for 4 hours and then at 75°C for 2 hours for polymerization to obtain polymer A. To 100 parts by mass of this polymer A, 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 "Naccem Ferric II", manufactured by Nippon Chemical Industry Co., Ltd.) were added to obtain an adhesive composition. The 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 produce a sheet-like adhesive layer having a thickness (average thickness) of 50 μm. Three sheets of this adhesive layer were stacked to obtain a thermoplastic resin composition (non-colored adhesive layer 1) having a thickness of 150 μm.

[0150] Preparation Example 5 (Preparation of Colored Adhesive Layer 1) 64.55 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), acrylic resin B (trade name "UC-3000", carboxyl group-containing acrylic resin, manufactured by Toagosei Co., Ltd.) 32 parts by mass, trade name "Carbon Black #20" (manufactured by Mitsubishi Chemical Corporation) 0.3 parts by mass, and silane coupling agent (trade name "KBM-303", manufactured by Shin-Etsu Chemical Co., Ltd.) 3 parts by mass were dissolved in methyl ethyl ketone to prepare 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 (colored adhesive layer 1) having a thickness (average thickness) of 50 μm.

[0151] Preparation Example 6 (Preparation of Colored Adhesive Layer 2) A sheet-like thermosetting resin composition (colored adhesive layer 2) was produced in the same manner as in Preparation Example 5 except that the thickness (average thickness) was 80 μm.

[0152] Preparation Example 7 (Preparation of Colored Adhesive Layer 3) A sheet-like thermosetting resin composition (colored adhesive layer 3) was produced in the same manner as in Preparation Example 5 except that the thickness (average thickness) was 160 μm.

[0153] Examples 1 to 4, Comparative Example 1 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.

[0154] <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.

[0155] (1) Elastic modulus G' at 130 °C before curing The resin compositions obtained in the preparation examples were laminated to prepare a laminate of the resin composition with a thickness of about 300 μm, punched into a cylindrical shape with a diameter of φ8 mm to obtain a measurement sample. Using a rheometer (trade name "HAAKE MARS III 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 to calculate the elastic modulus G' at 130 °C.

[0156] (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, cut into strips with a width of 10 mm × a length of 40 mm using a cutter knife to obtain a measurement sample. Using a solid viscoelasticity measuring device (trade name "RSA III", manufactured by Rheometric Scientific), the above measurement sample was 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.

[0157] (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, 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 a measurement sample. Using a solid viscoelasticity measuring device (trade name "RSA III", manufactured by Rheometric Scientific), the above measurement sample was 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.

[0158] (4) Light transmittance after curing Regarding the resin composition obtained in the preparation example, a 50-μm-thick sample was separately prepared in the same manner, and then heated at 150 °C for 1 hour to cure it, serving as 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.

[0159] (5) Haze value Regarding the resin composition obtained in the preparation example and the encapsulation sheets obtained in the examples and comparative examples, 50-μm-thick samples were separately prepared in the same manner, and then heated at 150 °C for 1 hour to cure them, and further stored at 125 °C for 1000 hours as 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 D65 light source.

[0160] (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 at 130 °C × 0.3 MPa × 600 seconds using a vacuum press device, 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 a Dekak, and the difference between the maximum and minimum values of the surface undulation was measured. Then, the appearance was evaluated based on the following evaluation criteria. [Evaluation criteria] ◎: The difference between the maximum and minimum values of the surface undulation is less than 2 μm 〇: The difference between the maximum and minimum values of the surface undulation exceeds 2 μm and is less than 4 μm ×: The difference between the maximum and minimum values of the surface undulation exceeds 4 μm

[0161] (7) Antireflection property Samples were prepared by laminating the surface of the release liner on the optoelectronic device side of the encapsulation sheet obtained in the examples and comparative examples onto an aluminum foil after peeling off the release liner. The obtained samples were installed in a product named "SolidSpec3700" (manufactured by Shimadzu Corporation) such that the release liner on the side opposite to the optoelectronic device side faced the light source side, and the reflectance (%) at 280 to 780 nm was measured. Then, the antireflection property was evaluated based on the following evaluation criteria. [Evaluation Criteria] ◎: Reflectance at 550 nm is 8.5% or less 〇: Reflectance at 550 nm exceeds 8.5% and is 10% or less △: Reflectance at 550 nm exceeds 10% and is 25% or less ×: Reflectance at 550 nm exceeds 25%

[0162] (8) Workability The samples after encapsulation prepared in the above appearance evaluation were diced into a size of 10 mm × 10 mm, and the amount of resin overflow and creep from the wafer edge were evaluated. Then, the workability was evaluated based on the following evaluation criteria. [Evaluation Criteria] ◎: The amount of resin overflow and creep from the wafer edge is less than 10 μm ×: The amount of resin overflow and creep from the wafer edge is 10 μm or more

[0163] (9) Chipping The samples used in the above workability evaluation were observed to confirm the amount of chipping, and the evaluation was performed 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

[0164] (10) Reliability After the samples after encapsulation prepared in the above appearance evaluation were subjected to 3 cycles at 260 °C for 1 minute, the presence or absence of peeling between the encapsulation sheet and the wafer was confirmed using SAT. Then, the reliability was evaluated based on the following evaluation criteria. [Evaluation Criteria] ◎: Among those input with n9, those that appear as a black shadow in SAT are 0 / 9 〇: Among those input with n9, those that appear as a black shadow in SAT are 1 / 9 or more and 3 / 9 or less ×: Among those input with n9, those that appear as a black shadow in SAT are 4 / 9 or more

[0165]

Table 1

[0166] As shown in Table 1, the encapsulation sheet of the example has antireflection properties, excellent workability, no chipping, and was evaluated as having excellent reliability. On the other hand, when a non-colored pressure-sensitive adhesive layer was used instead of the non-colored adhesive layer (Comparative Example 1), it was evaluated as having inferior workability, chipping occurred, voids occurred during encapsulation, and reliability was inferior.

[0167] Hereinafter, variations of the invention according to the present disclosure will be described. [Appendix 1] A sheet for encapsulating one or more optical semiconductor elements disposed on a substrate, The sheet includes an encapsulation resin layer including at least a colored layer and a non-colored adhesive layer having thermosetting properties, The colored layer contains a colorant, The non-colored adhesive layer has a storage modulus G' of 0.5 to 10 kPa at 130°C before curing and is a layer that contacts the optical semiconductor element when the optical semiconductor element is encapsulated. A sheet for encapsulating an optical semiconductor element. [Appendix 2] The sheet for encapsulating an optical semiconductor element according to Appendix 1, wherein the thickness of the non-colored adhesive layer is 5 to 75 μm. [Appendix 3] The sheet for encapsulating an optical semiconductor element according to Appendix 1 or 2, wherein the storage modulus E' of the non-colored adhesive layer at room temperature before curing is 500 to 4000 MPa. [Appendix 4] The sheet for encapsulating an optical semiconductor element according to any one of Appendices 1 to 3, wherein the storage modulus E' of the non-colored adhesive layer at room temperature after curing is 500 to 4000 MPa. [Supplementary Note 5] The light-transmittance at a wavelength of 600 nm after curing of the non-coloring adhesive layer is more than 80%. A sheet for encapsulating an optical semiconductor device according to any one of Supplementary Notes 1 to 4. [Supplementary Note 6] In a state where an optical semiconductor device is encapsulated, the distance from the optical semiconductor device to the non-coloring adhesive layer is 0 to 20 μm. A sheet for encapsulating an optical semiconductor device according to any one of Supplementary Notes 1 to 5. [Supplementary Note 7] The coloring layer is a thermosetting coloring adhesive layer. The light-transmittance at a wavelength of 600 nm after curing of the coloring adhesive layer is 0 to 80%. A sheet for encapsulating an optical semiconductor device according to any one of Supplementary Notes 1 to 6. [Supplementary Note 8] The coloring layer is a thermosetting coloring adhesive layer. The ratio [elastic modulus E' at room temperature after curing / elastic modulus E' at room temperature before curing] of the elastic modulus E' at room temperature after curing of the coloring adhesive layer to the elastic modulus E' at room temperature before curing is 0.6 to 2.0. A sheet for encapsulating an optical semiconductor device according to any one of Supplementary Notes 1 to 7. [Supplementary Note 9] 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 in contact with the optical semiconductor device. A sheet for encapsulating an optical semiconductor device according to any one of Supplementary Notes 1 to 8. [Supplementary Note 10] An optical semiconductor device including a substrate, an optical semiconductor device disposed on the substrate, and the sheet for encapsulating an optical semiconductor device according to any one of Supplementary Notes 1 to 9 or a cured product thereof.

Explanation of Signs

[0168] 1 Sheet for encapsulating an optical semiconductor device 2 Encapsulating resin layer 21 Non-coloring adhesive layer 22 Coloring layer 3 Release liner 4 Base material part 41 Base material film 42 Functional layer 5 Substrate 6 Optical semiconductor device 7 Cured encapsulation layer 71 Non-coloring adhesive layer 72 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 includes an encapsulating resin layer including at least a colored layer and a non-colored adhesive layer having thermosetting properties, the colored layer contains a colorant, the non-colored adhesive layer has a storage modulus G' of 0.5 to 10 kPa at 130°C before curing and is a layer that contacts the optical semiconductor element when the optical semiconductor element is encapsulated, the sheet for encapsulating an optical semiconductor element.

2. The sheet for encapsulating an optical semiconductor element according to claim 1, wherein the thickness of the non-colored adhesive layer is 5 to 75 μm.

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

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

5. The sheet for encapsulating an optical semiconductor element according to claim 1 or 2, wherein the light transmittance of the non-colored adhesive layer at a wavelength of 600 nm after curing is more than 80%.

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

7. The colored layer is a colored adhesive layer having thermosetting properties, The sheet for encapsulating an optical semiconductor element 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 colored layer is a colored adhesive layer having thermosetting properties, The sheet for encapsulating an optical semiconductor element according to claim 1 or 2, wherein the ratio [storage modulus E' after curing / storage modulus E' before curing] of the storage modulus E' of the colored adhesive layer at room temperature after curing to the storage modulus E' at room temperature before curing is 0.6 to 2.

0.

9. The sheet for encapsulating an optical semiconductor element according to claim 1 or 2, further comprising a layer having antiglare properties and / or antireflection properties on a surface of the encapsulating resin layer 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 sheet for encapsulating an optical semiconductor element according to claim 1 or 2 or a cured product thereof for encapsulating the optical semiconductor element.

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