CN116423948A

CN116423948A - Optical semiconductor element sealing sheet

Info

Publication number: CN116423948A
Application number: CN202211664510.XA
Authority: CN
Inventors: 田中俊平; 植野大树; 长束尚辉; 仲野武史; 浅井量子; 福富秀平
Original assignee: Nitto Denko Corp
Current assignee: Nitto Denko Corp
Priority date: 2021-12-24
Filing date: 2022-12-23
Publication date: 2023-07-14
Also published as: CN117799261A; TW202342686A; JP7369760B2; JP7451815B2; JP2023095089A; JP2023164767A; KR20230098045A

Abstract

Provided is a sheet for sealing an optical semiconductor element, which has excellent appearance in the state in which the optical semiconductor element is sealed, and which is less likely to cause uneven brightness. The optical semiconductor element sealing sheet (1) is a sheet for sealing 1 or more optical semiconductor elements (6) arranged on a substrate (5). An optical semiconductor element sealing sheet (1) is provided with: a first sealing layer (21) in contact with the optical semiconductor element (6), a second sealing layer (22) laminated on the first sealing layer (21), and a third sealing layer (23) laminated on the second sealing layer (22) and having adhesiveness and/or adhesiveness. The second sealing layer (22) and/or the third sealing layer (23) comprise a colorant. More than 1 selected from the group consisting of a first sealing layer (21), a second sealing layer (22) and a third sealing layer (23) are diffusion functional layers.

Description

Optical semiconductor element sealing sheet

Technical Field

The present invention relates to an optical semiconductor element sealing sheet. More specifically, the present invention relates to a sealing sheet suitable for sealing an optical semiconductor element of a self-luminous display device such as a mini/micro LED.

Background

In recent years, as a new generation display device, a self-luminous display device typified by a Mini/micro LED display device (Mini/Micro Light Emitting Diode Display) has been designed. As a basic configuration of a mini/micro LED display device, a substrate in which a large number of micro optical semiconductor elements (LED chips) are densely arranged is used as a display panel, the optical semiconductor elements are sealed with a sealing material, and a cover member such as a resin film or a glass plate is laminated on the outermost layer.

In self-luminous display devices such as mini-LED display devices, wiring (metal wiring) of metal, metal oxide such as ITO, and the like is arranged on a substrate of a display panel. Such a display device has the following problems, for example: when the light is turned off, the light is reflected by the metal wiring or the like, and the appearance of the screen is deteriorated. Therefore, as a sealing material for sealing the optical semiconductor element, a technique using an antireflection layer for preventing reflection by a metal wiring is adopted.

In addition, in a display using a self-luminous display device such as a backlight, there is a problem in that uneven brightness (uneven brightness) occurs due to a light source of an optical semiconductor element. Patent document 1 discloses, as an adhesive sheet capable of suppressing luminance unevenness, an adhesive sheet having a composite adhesive layer including a light-diffusing adhesive layer containing light-diffusing particles and a transparent adhesive layer containing no light-diffusing particles, at least one of the light-diffusing adhesive layer and the transparent adhesive layer being formed of an active energy ray-curable adhesive.

Patent document 2 discloses an adhesive sheet which is a laminate of a colored adhesive layer and a colorless adhesive layer, the colorless adhesive layer being located on a surface of the adhesive layer which contacts with irregularities of an adherend. It is described that the pressure-sensitive adhesive sheet can suppress uneven brightness in the pressure-sensitive adhesive layer.

Prior art literature

Patent literature

Patent document 1: japanese patent application laid-open No. 2021-38365

Patent document 2: japanese patent laid-open No. 2020-169262

Disclosure of Invention

Problems to be solved by the invention

However, the adhesive sheet of patent document 1 does not have an antireflection layer, and does not solve the problem of appearance. In the pressure-sensitive adhesive sheet described in patent document 2, it is considered that the colored pressure-sensitive adhesive layer functions as an antireflection layer, but the suppression of uneven brightness is insufficient.

The present invention has been made in view of the above circumstances, and an object thereof is to provide an optical semiconductor element sealing sheet which has excellent appearance in a state where an optical semiconductor element is sealed and which is less likely to cause luminance unevenness.

Solution for solving the problem

As a result of intensive studies to achieve the above object, the present inventors have found that an optical semiconductor element sealing sheet comprising 3 sealing layers, wherein 1 or more of the 3 layers are light diffusion preventing layers and a colorant is blended in a specific sealing layer, has excellent appearance in a state of sealing an optical semiconductor element, and is less likely to cause luminance unevenness. The present invention has been completed based on these findings.

That is, the present invention provides an optical semiconductor element sealing sheet for sealing 1 or more optical semiconductor elements arranged on a substrate,

the sheet comprises: a first sealing layer in contact with the optical semiconductor element; a second sealing layer laminated on the first sealing layer; and a third sealing layer laminated on the second sealing layer and having adhesiveness and/or adhesiveness,

the second sealing layer and/or the third sealing layer comprises a colorant,

more than 1 selected from the group consisting of the first sealing layer, the second sealing layer, and the third sealing layer is a diffusion functional layer.

As described above, the optical semiconductor element sealing sheet has a structure in which a first sealing layer, a second sealing layer, and a third sealing layer, which are in contact with the optical semiconductor element, are sequentially stacked. And, 1 or more selected from the group consisting of the first sealing layer, the second sealing layer, and the third sealing layer are diffusion functional layers, and the second sealing layer and/or the third sealing layer contain a colorant. The sealing layer containing the colorant functions as an antireflection layer. The third sealing layer has adhesion and/or adhesiveness, and therefore, in a state in which the third sealing layer is laminated on another member, the following property of the interface is excellent. With such a configuration, the optical semiconductor element is sealed with the sheet, and the effect of suppressing the luminance unevenness and the appearance can be simultaneously achieved.

Preferably, the first sealing layer is a diffusion functional layer. With such a configuration, the appearance tends to be further improved.

Preferably, the third sealing layer is a diffusion functional layer. With such a configuration, the luminance unevenness tends to be further suppressed.

Preferably, the diffusion functional layer contains light diffusing fine particles. Preferably, the light diffusing fine particles are composed of a silicone resin and/or a metal oxide. With such a configuration, the diffusion functional layer is more excellent in light diffusibility, and luminance unevenness is further suppressed.

Preferably, the optical semiconductor element sealing sheet is defined as L below ^* (SCI) (2) relative to L ^* Ratio of (SCI) (1) [ L ] ^* (SCI)(2)/L ^* (SCI)(1)]And/or L ^* (SCE) (2) relative to L ^* Ratio of (SCE) (1) [ L ] ^* (SCE)(2)/L ^* (SCE)(1)]Is 1.2 or less. With such a configuration, the optical semiconductor device has excellent appearance even when the height difference due to the optical semiconductor device is high.

L ^* (SCI) (1): l x (SCI) measured from the third sealing layer side in a state where the first sealing layer of the optical semiconductor element sealing sheet is bonded to the aluminum foil

L ^* (SCI) (2): l x (SCI) measured from the third sealing layer side in the following state: a convex sample having an aluminum foil on the surface thereof and having a length of 20mm by a width of 20mm by a thickness of 62 μm is placed on a substrate having a larger size than the convex sample, and a first sealing layer of the optical semiconductor element sealing sheet is bonded to the substrate and the convex sample so that the optical semiconductor element sealing sheet covers the convex sample

L ^* (SCE) (1): bonding the first sealing layer of the optical semiconductor element sealing sheet to the aluminum foilL (SCE) measured from the third sealing layer side in the state of (2)

L ^* (SCE) (2): l (SCE) measured from the third sealing layer side in the following state: a convex sample having an aluminum foil on the surface thereof and having a length of 20mm by a width of 20mm by a thickness of 62 μm is placed on a substrate having a size larger than the convex sample, and a first sealing layer of the optical semiconductor element sealing sheet is bonded to the substrate and the convex sample so that the optical semiconductor element sealing sheet covers the convex sample.

Preferably, the first sealing layer is a non-radiation curable resin layer. With this configuration, the first sealing layer located on the surface of the optical semiconductor element sealing sheet has excellent adhesion between the optical semiconductor element and the substrate when sealing the optical semiconductor element, and has excellent followability and landfill property of the optical semiconductor element. As a result, the optical semiconductor device has excellent appearance even when the height difference due to the optical semiconductor device is high.

Preferably, the second sealing layer and/or the third sealing layer is a radiation curable resin layer. With such a configuration, after sealing the optical semiconductor element, the second sealing layer and/or the third sealing layer is cured by irradiation with radiation, and the adhesiveness of the optical semiconductor element sealing sheet side surface is reduced. In this way, the adhesion between the sheets in the adjacent optical semiconductor devices in the flat state is reduced, and chipping of the sheets and adhesion of the sheets of the adjacent optical semiconductor devices are less likely to occur when the adjacent optical semiconductor devices are pulled apart from each other.

The present invention also provides an optical semiconductor device including: the semiconductor device includes a substrate, an optical semiconductor element disposed on the substrate, and the optical semiconductor element sealing sheet for sealing the optical semiconductor element. Such an optical semiconductor device is excellent in appearance and less likely to cause luminance unevenness.

Preferably, the optical semiconductor device is a self-luminous display device.

The present invention also provides an image display device including the self-luminous display device.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the optical semiconductor element sealing sheet of the present invention, the optical semiconductor element is sealed with excellent appearance, and luminance unevenness is less likely to occur. Accordingly, by using the optical semiconductor element sealing sheet of the present invention, the following optical semiconductor device can be provided: the light emitted from the optical semiconductor element can be efficiently passed in a diffused state while the optical semiconductor element is not lit.

Drawings

Fig. 1 is a cross-sectional view of an optical semiconductor element sealing sheet according to an embodiment of the present invention.

Fig. 2 is a cross-sectional view of an optical semiconductor device using an optical semiconductor element sealing sheet according to an embodiment of the present invention.

Fig. 3 is an external view showing an embodiment of an optical semiconductor device manufactured by tiling the optical semiconductor device shown in fig. 2.

Fig. 4 is a cross-sectional view showing a state of a sealing process in one embodiment of a method for manufacturing an optical semiconductor device.

Fig. 5 is a cross-sectional view showing the laminate obtained after the sealing process shown in fig. 4.

Fig. 6 is a cross-sectional view showing a cutting position in the cutting process of the laminate shown in fig. 5.

Description of the reference numerals

1. Optical semiconductor element sealing sheet

2. Sealing part

21. First sealing layer

22. Second sealing layer

23. Third sealing layer

3. Release liner

4. Base material part

5. Substrate board

6. Optical semiconductor element

10. 20-photon semiconductor device

Detailed Description

[ sheet for sealing optical semiconductor element ]

The optical semiconductor element sealing sheet of the present invention comprises at least: a first sealing layer in contact with the optical semiconductor element, a second sealing layer laminated on the first sealing layer, and a third sealing layer laminated on the second sealing layer. The first sealing layer is a layer which is to be in contact with the optical semiconductor element when the optical semiconductor element is sealed. In the above-described optical semiconductor element sealing sheet, it is preferable that the first sealing layer and the second sealing layer, and the second sealing layer and the third sealing layer are directly laminated.

In the present specification, the optical semiconductor element sealing sheet refers to a sheet for sealing 1 or more optical semiconductor elements disposed on a substrate. In the present specification, "sealing the optical semiconductor element" means embedding at least a part of the optical semiconductor element in a sealing portion having a first sealing layer, a second sealing layer, and a third sealing layer, or following and covering the sealing portion.

The optical semiconductor element sealing sheet of the present invention may be provided on at least one surface of the base material portion, or may be formed on a release-treated surface of a release liner. When the optical semiconductor element sealing sheet of the present invention includes the base material portion, the third sealing layer side of the optical semiconductor element sealing sheet of the present invention is the side contacting the base material portion. When the optical semiconductor element sealing sheet of the present invention is formed on the release liner, the first sealing layer side of the optical semiconductor element sealing sheet of the present invention is the side in contact with the release liner. When the base material portion is not provided, both the first sealing layer side and the third sealing layer side of the optical semiconductor element sealing sheet may be the sides in contact with the release liner. The release liner is used as a protective material for the optical semiconductor element sealing sheet, and is peeled off when sealing an optical semiconductor element. The base material portion and the release liner are not necessarily provided.

An embodiment of the optical semiconductor element sealing sheet of the present invention will be described below. Fig. 1 is a cross-sectional view showing an embodiment of the optical semiconductor element sealing sheet of the present invention. As shown in fig. 1, the optical semiconductor element sealing sheet 1 is used for sealing 1 or more optical semiconductor elements arranged on a substrate, and includes a base material portion 4 and a sealing portion 2 formed on the base material portion 4. The sealing portion 2 is formed of a laminate of a first sealing layer 21, a second sealing layer 22, and a third sealing layer 23. The second seal layer 22 is directly laminated on the first seal layer 21, and the third seal layer 23 is directly laminated on the second seal layer 22. A release liner 3 is attached to one side of the first seal layer 21, and a base material portion 4 is attached to the third seal layer 23.

In the above-described optical semiconductor element sealing sheet, the second sealing layer and/or the third sealing layer contains a colorant. That is, at least one of the second sealing layer and the third sealing layer contains a colorant. The sealing layer containing the colorant functions as an antireflection layer. Therefore, the optical semiconductor element is sealed by the optical semiconductor element sealing sheet, and the appearance is excellent.

The optical semiconductor element sealing sheet includes at least a layer (diffusion function layer) that functions to diffuse light. In the above-mentioned optical semiconductor element sealing sheet, 1 or more selected from the group consisting of the first sealing layer, the second sealing layer and the third sealing layer are diffusion functional layers. Among the first, second and third sealing layers, the layer as the diffusion functional layer is a colorless layer containing no colorant. For example, when the second seal layer is a colored layer and the third seal layer is a diffusion functional layer, the third seal layer is a colorless layer, when the third seal layer is a colored layer and the second seal layer is a diffusion functional layer, the second seal layer is a colorless layer, and when the second seal layer and the third seal layer are colored layers, the first seal layer is a colorless diffusion functional layer. With such a configuration, the antireflection layer and the diffusion functional layer can exhibit sufficient effects, and the effect of suppressing luminance unevenness and the appearance can be simultaneously achieved in a state in which the optical semiconductor element is sealed by the optical semiconductor element sealing sheet.

As the laminated structure of the first sealing layer, the second sealing layer, and the third sealing layer [ first sealing layer/second sealing layer/third sealing layer ], there are exemplified [ diffusion functional layer/coloring layer/non-diffusion functional layer ], [ non-diffusion functional layer/coloring layer/diffusion functional layer ], [ non-diffusion functional layer/coloring layer ], [ diffusion functional layer/non-diffusion functional layer/coloring layer ], [ diffusion functional layer/coloring layer ]. In the present specification, the "diffusion functional layer" refers to a layer containing no colorant, and the "non-diffusion functional layer" refers to a colorless and transparent layer which does not exhibit a light diffusion function.

Preferably, one of the second sealing layer and the third sealing layer is a colored layer, and the other is a colorless layer containing no colorant. In this case, at least one of the colorless layer and the first sealing layer is a diffusion functional layer, but preferably one is a diffusion functional layer and the other is a non-diffusion functional layer. In these cases, the effect of suppressing the luminance unevenness and the appearance tend to be more excellent.

Among them, the second sealing layer is preferably a coloring layer. In this case, the third sealing layer may be a colored layer or a colorless layer, but is preferably a colorless layer. When the third sealing layer is a colorless layer, the first sealing layer and/or the third sealing layer is a diffusion functional layer. Among these, one of the first seal layer and the third seal layer is preferably a diffusion functional layer, the other is a non-diffusion functional layer, more preferably the first seal layer is a diffusion functional layer, further preferably the first seal layer is a diffusion functional layer, and the third seal layer is a non-diffusion functional layer. In these cases, the effect of suppressing the luminance unevenness and the appearance tend to be more excellent.

The laminated structure [ first sealing layer/second sealing layer/third sealing layer ] is preferably [ diffusion functional layer/coloring layer/non-diffusion functional layer ], [ non-diffusion functional layer/coloring layer/diffusion functional layer ], [ non-diffusion functional layer/coloring layer ], [ diffusion functional layer/non-diffusion functional layer/coloring layer ], more preferably [ 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 ].

The first sealing layer, the second sealing layer, and the third sealing layer may be each independently a resin layer (radiation curable resin layer) having a property of being cured by radiation irradiation, or may be a resin layer (non-radiation curable resin layer) having no property of being cured by radiation irradiation. Examples of the radiation include electron beam, ultraviolet ray, α ray, β ray, γ ray, and X ray.

The first sealing layer is preferably a non-radiation curable resin layer. With this configuration, the first sealing layer located on the surface of the optical semiconductor element sealing sheet has excellent adhesion between the optical semiconductor element and the substrate when sealing the optical semiconductor element, and has excellent followability and landfill property of the optical semiconductor element. As a result, the optical semiconductor device has excellent appearance even when the height difference due to the optical semiconductor device is high.

Preferably, the second sealing layer and/or the third sealing layer is a radiation curable resin layer. With such a configuration, after sealing the optical semiconductor element, the second sealing layer and/or the third sealing layer is cured by irradiation of radiation, and the adhesiveness of the optical semiconductor element sealing sheet side surface is reduced. In this way, the adhesion between the sheets in the adjacent optical semiconductor devices in the flat state is reduced, and chipping of the sheets and adhesion of the sheets of the adjacent optical semiconductor devices are less likely to occur when the adjacent optical semiconductor devices are pulled apart from each other.

The first sealing layer is a layer that is to be a side that contacts the optical semiconductor element (i.e., a substrate side provided with the optical semiconductor element) when the optical semiconductor element is sealed. The first sealing layer may or may not have adhesion and/or cohesive properties. Among these, in order to allow the first sealing layer to adhere to the substrate and the optical semiconductor element with a sufficient adhesion force and to sufficiently seal the optical semiconductor element, it is preferable that the first sealing layer has an adhesive property and/or an adhesive property.

The second sealing layer may or may not have adhesion and/or cohesive properties. Among them, adhesion and/or adhesiveness are preferable. With such a configuration, the optical semiconductor element can be easily sealed when the optical semiconductor element is sealed, and the first sealing layer on the optical semiconductor element side surface has excellent adhesion to the optical semiconductor element, and the optical semiconductor element has more excellent sealing properties.

The third sealing layer has adhesiveness and/or tackiness. Thus, the interface following property is excellent in a state where the third sealing layer is laminated with other members. Therefore, in the state in which the optical semiconductor element is sealed by the optical semiconductor element sealing sheet, the third sealing layer is less likely to generate a gap with other members that are in close contact or in adhesion, and the effect of suppressing luminance unevenness and the appearance can be simultaneously achieved. In addition, when the optical semiconductor element is sealed, the optical semiconductor element can be easily sealed, and further, the adhesion with the second sealing layer is excellent, and the sealing property of the optical semiconductor element is more excellent.

(colored layer)

The colored layer which may correspond to the second seal layer and/or the third seal layer contains at least a colorant. The colored layer is preferably a resin layer made of a resin. The colorant may be a dye or a pigment as long as it can be dissolved or dispersed in the colored layer. Dyes are preferred from the viewpoint that low haze can be achieved even with a small amount of addition, no sedimentation is possible as in pigments, and uniform distribution is easy. In addition, pigments are also preferred in terms of high color rendering properties even when added in small amounts. When pigments are used as colorants, it is preferred that the conductivity be low or not. The colorant may be used alone or in combination of two or more.

The colorant is preferably a black colorant. Examples of the black-based colorant include colorants (pigments, dyes, etc.) for developing a known conventional black color, and examples thereof include carbon black (furnace black, channel black, acetylene black, thermal black, lamp black, pine black, etc.), graphite, copper oxide, manganese dioxide, aniline black, perylene black, titanium black, cyanine black, activated carbon, ferrite (nonmagnetic ferrite, magnetic ferrite, etc.), magnet (magnetite), chromium oxide, iron oxide, molybdenum disulfide, chromium complex, anthraquinone-based colorant, zirconium nitride, etc. The black colorant may be used alone or in combination of two or more. Further, a colorant that is combined and mixed to exhibit a color other than black may be used and functions as a black-based colorant.

The colorant is not particularly limited, but is preferably a colorant that absorbs visible light and has ultraviolet transmittance. That is, the average transmittance of the colorant at a wavelength of 330 to 400nm is preferably larger than the average transmittance at a wavelength of 400 to 700 nm. The maximum value of the transmittance of the colorant at a wavelength of 330 to 400nm is preferably larger than the maximum value of the transmittance at a wavelength of 400 to 700 nm. The transmittance of the colorant is measured using a solution or dispersion in which the colorant is diluted with an appropriate solvent or dispersion medium (an organic solvent having a small absorption in the wavelength range of 330 to 700 nm) such as Tetrahydrofuran (THF) or the like so that the transmittance at a wavelength of 400nm is about 50 to 60%.

Examples of the BLACK pigment having ultraviolet transmittance, which has ultraviolet absorption smaller than that of visible light, include a trade name "9050BLACK", a trade name "UVBK-0001" (manufactured by TOKUSHIKI co., ltd), and the like. Examples of the black dye having ultraviolet transmittance include the trade name "SOC-L-0123" (manufactured by ORIENT CHEMICAL INDUSTRIES).

Carbon black and titanium black, which are generally used as black colorants, absorb ultraviolet light more than visible light (ultraviolet transmittance is less than visible light transmittance). Therefore, when a colorant such as carbon black is added to a radiation curable resin having sensitivity to ultraviolet rays, most of the ultraviolet rays irradiated for photocuring are absorbed by the colorant, the amount of light absorbed by the photopolymerization initiator is small, and the time required for photocuring (the cumulative irradiation light amount increases). In addition, when the thickness of the laminated layers is large, ultraviolet rays reaching the surface opposite to the light irradiation surface are small, and thus, even if light irradiation is performed for a long period of time, light curing tends to be insufficient. In contrast, by using a colorant having a transmittance of ultraviolet rays larger than that of visible light, curing inhibition caused by the colorant can be suppressed.

The content of the colorant in the colored layer is preferably 0.01 to 20 parts by mass, more preferably 0.1 to 15 parts by mass, still more preferably 1 to 10 parts by mass, based on 100 parts by mass of the resin constituting the colored layer, from the viewpoint of imparting an appropriate antireflection capability to the semiconductor element sealing sheet, and may be appropriately set depending on the type of colorant, the color tone of the semiconductor element sealing sheet, the light transmittance, and the like. The colorant may be added to the composition in the form of a solution or dispersion dissolved or dispersed in a suitable solvent.

The haze value (initial haze value) of the colored layer is not particularly limited, but is preferably 30% or less, more preferably 25% or less, further preferably 20% or less, and particularly preferably 15% or less from the viewpoint of securing visibility of the optical semiconductor device. In order to efficiently reduce the luminance unevenness of the optical semiconductor device, the haze value of the colored layer is preferably 1% or more, more preferably 3% or more, still more preferably 5% or more, particularly preferably 8% or more, and may be 10% or more. When the colored layer is a radiation curable resin layer, the haze value may be a value before curing or a value after curing.

The total light transmittance of the colored layer is not particularly limited, but is preferably 30% or less, more preferably 25% or less, further preferably 20% or less, and particularly preferably 10% or less, from the viewpoint of further improving the anti-reflection function and contrast of metal wiring and the like in the optical semiconductor device. Further, from the viewpoint of securing the luminance of the optical semiconductor device, the total light transmittance of the colored layer is preferably 0.5% or more, more preferably 1% or more, still more preferably 1.5% or more, particularly preferably 2% or more, and may be 2.5% or more or 3% or more. When the colored layer is a radiation curable resin layer, the total light transmittance may be a value before curing or a value after curing.

The haze value and the total light transmittance of the colored layer can be measured by the methods defined in JIS K7136 and JIS K7361-1, and can be controlled by the type, thickness, type of colorant, blending amount, and the like.

(diffusion functional layer)

The diffusion functional layer which can correspond to the first sealing layer, the second sealing layer, and the third sealing layer is a layer having a function of diffusing light, and is preferably a resin layer made of a resin. The diffusion functional layer is not limited, and preferably contains light diffusing fine particles. That is, the diffusion functional layer preferably contains light diffusing fine particles dispersed in a resin layer. The light diffusing fine particles may be used alone or in combination of two or more.

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

The polymer fine particles are preferably fine particles made of silicone resin. The inorganic fine particles are preferably fine particles composed of a metal oxide. The metal oxide is preferably titanium oxide or barium titanate, more preferably titanium oxide. With such a configuration, the diffusion functional layer is more excellent in light diffusibility and further suppressed in luminance unevenness.

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

The average particle diameter of the 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, from the viewpoint of imparting an appropriate light diffusing property to the sheet for sealing a semiconductor element. In addition, the average particle diameter of the light diffusing fine particles is preferably 12 μm or less, more preferably 10 μm or less, and even more preferably 8 μm or less, from the viewpoint of preventing the haze value from becoming too high and displaying a high-definition image. The average particle diameter can be measured, for example, using a coulter counter.

The refractive index of the 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.

From the viewpoint of reducing luminance unevenness of the optical semiconductor device more efficiently, the absolute value of the refractive index difference between the 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, particularly preferably 0.03 or more, and may be 0.04 or more or 0.05 or more. In addition, from the viewpoint of preventing the haze value from becoming too high and displaying a high-definition image, the absolute value of the refractive index difference between the light diffusing fine particles and the resin is preferably 5 or less, more preferably 4 or less, and still more preferably 3 or less.

The content of the light diffusing fine particles in the diffusion functional layer is preferably 0.01 parts by mass or more, more preferably 0.05 parts by mass or more, still more preferably 0.1 parts by mass or more, and particularly preferably 0.15 parts by mass or more, relative to 100 parts by mass of the resin constituting the diffusion functional layer, from the viewpoint of imparting an appropriate light diffusing performance to the optical semiconductor element sealing sheet. Further, from the viewpoint 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, relative to 100 parts by mass of the resin constituting the diffusion functional layer.

The haze value (initial haze value) of the diffusion functional layer is not particularly limited, but is preferably 30% or more, more preferably 40% or more, further 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, and further, the effect of improving the luminance unevenness is more excellent in the vicinity of 99.9% from the viewpoint of efficiently reducing the luminance unevenness of the optical semiconductor device. The upper limit of the haze value of the diffusion functional layer is not particularly limited, that is, may be 100%. When the diffusion functional layer is a radiation curable resin layer, the haze value may be a value before curing or a value after curing.

The total light transmittance of the diffusion functional layer is not particularly limited, but is preferably 40% or more, more preferably 60% or more, still more preferably 70% or more, and still more preferably 80% or more from the viewpoint of securing the luminance of the optical semiconductor device. The upper limit of the total light transmittance of the diffusion functional layer is not particularly limited, and may be less than 100%, or 99.9% or less or 99% or less. When the diffusion functional layer is a radiation curable resin layer, the total light transmittance may be a value before curing or a value after curing.

The haze value and the total light transmittance of the diffusion functional layer 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 of the light diffusing fine particles, the blending amount, and the like.

(non-diffusion functional layer)

The non-diffusion functional layer which can correspond to the first, second, and third sealing layers is a colorless transparent layer which does not function to diffuse light, and is preferably a resin layer made of a resin.

The haze value (initial haze value) of the non-diffusion functional layer is not particularly limited, but is preferably less than 30%, more preferably 10% or less, further preferably 5% or less, particularly preferably 1% or less, and may be 0.5% or less, from the viewpoint of making the luminance of the optical semiconductor device excellent. The lower limit of the haze value of the non-diffusion functional layer is not particularly limited. When the non-diffusion functional layer is a radiation curable resin layer, the haze value may be a value before curing or a value after curing.

The total light transmittance of the non-diffusion functional layer is not particularly limited, but is preferably 60% or more, more preferably 70% or more, still more preferably 80% or more, and particularly preferably 90% or more from the viewpoint of securing the luminance of the optical semiconductor device. The upper limit of the total light transmittance of the non-diffusion functional layer is not particularly limited, and may be less than 100%, or 99.9% or less or 99% or less. When the non-diffusion functional layer is a radiation curable resin layer, the total light transmittance may be a value before curing or a value after curing.

The haze value and the total light transmittance of the non-diffusion functional layer can be measured by the methods defined in JIS K7136 and JIS K7361-1, and can be controlled by the type, thickness, and the like of the non-diffusion functional layer.

From the viewpoint of making the luminance of the optical semiconductor device excellent, the content of the colorant and/or the light-diffusing fine particles in the non-diffusion functional layer is preferably less than 0.01 parts by mass, more preferably 0.005 parts by mass or less relative to 100 parts by mass of the resin constituting the non-diffusion functional layer.

< resin layer >

When the colored layer, the diffusion functional layer, and the non-diffusion functional layer are the resin layers, the resin constituting the resin layers may be any of known and conventional resins, for example, acrylic resins, urethane acrylate resins, urethane resins, rubber resins, epoxy acrylate resins, oxetane resins, silicone acrylic resins, polyester resins, polyether resins (such as polyvinyl ether), polyamide resins, fluorine resins, vinyl acetate/vinyl chloride copolymers, modified polyolefin, and the like. The resin may be used alone or in combination of two or more. The resins constituting the colored layer, the diffusion functional layer, and the non-diffusion functional layer may be the same or different from each other.

In the case where the resin layer is a layer having an adhesive property (adhesive layer), a known and conventionally used pressure-sensitive adhesive can be used as the resin. Examples of the adhesive include acrylic adhesives, rubber adhesives (natural rubber adhesives, synthetic rubber adhesives, and mixed systems thereof), silicone adhesives, polyester adhesives, urethane adhesives, polyether adhesives, polyamide adhesives, and fluorine adhesives. The binder may be used alone or in combination of two or more.

The acrylic resin is a polymer containing a structural unit derived from an acrylic monomer (a monomer component having a (meth) acryloyl group in a molecule) as a structural unit of the polymer. The acrylic resin may be used alone or in combination of two or more.

The acrylic resin is preferably a polymer containing the largest amount of structural units derived from (meth) acrylic esters in terms of mass ratio. In the present specification, "(meth) acrylic acid" means "acrylic acid" and/or "methacrylic acid" ("acrylic acid" and "methacrylic acid" either or both), and the other is the same.

Examples of the (meth) acrylate include hydrocarbon group-containing (meth) acrylates. Examples of the hydrocarbon group-containing (meth) acrylate include (meth) acrylic acid esters having an alicyclic hydrocarbon group such as alkyl (meth) acrylate and cycloalkyl (meth) acrylate having a linear or branched aliphatic hydrocarbon group, and (meth) acrylic acid esters having an aromatic hydrocarbon group such as aryl (meth) acrylate. The hydrocarbon group-containing (meth) acrylate may be used alone or in combination of two or more.

Examples of the alkyl (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, sec-butyl (meth) acrylate, tert-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, tridecyl (meth) acrylate, tetradecyl (meth) acrylate, pentadecyl (meth) acrylate, hexadecyl (meth) acrylate, octadecyl (meth) acrylate, and nonadecyl (meth) acrylate.

Among these alkyl (meth) acrylates, alkyl (meth) acrylates having a linear or branched aliphatic hydrocarbon group having 1 to 20 carbon atoms (preferably 1 to 14, more preferably 2 to 10, still more preferably 2 to 6) are preferable. When the carbon number is within the above range, the glass transition temperature of the acrylic resin can be easily adjusted, and the adhesiveness of the resin layer can be easily improved.

Examples of the alicyclic hydrocarbon group-containing (meth) acrylate include: (meth) acrylic esters having a monocyclic aliphatic hydrocarbon ring such as cyclopentyl (meth) acrylate, cyclohexyl (meth) acrylate, cycloheptyl (meth) acrylate, and cyclooctyl (meth) acrylate; (meth) acrylic esters having a bicyclic aliphatic hydrocarbon ring such as isobornyl (meth) acrylate; and (meth) acrylic esters having an aliphatic hydrocarbon ring having three or more rings, such as dicyclopentyl (meth) acrylate, dicyclopentyloxyethyl (meth) acrylate, tricyclopentyl (meth) acrylate, 1-adamantyl (meth) acrylate, 2-methyl-2-adamantyl (meth) acrylate, and 2-ethyl-2-adamantyl (meth) acrylate. Among them, preferred are (meth) acrylic esters having a monocyclic aliphatic hydrocarbon ring, and more preferred are cyclohexyl (meth) acrylate.

Examples of the (meth) acrylic acid ester having an aromatic hydrocarbon group include phenyl (meth) acrylate and benzyl (meth) acrylate.

Among these, alkyl (meth) acrylates having a linear or branched aliphatic hydrocarbon group are preferably used. Further, it is more preferable to contain a (meth) acrylate having an alicyclic hydrocarbon group. In this case, the balance of the adhesiveness of the resin layer is good, and the sealing property of the optical semiconductor element is more excellent.

In order to properly exhibit basic characteristics such as adhesiveness due to the hydrocarbon group-containing (meth) acrylate and adhesiveness to the semiconductor element in the resin layer, the ratio of the hydrocarbon group-containing (meth) acrylate in all the monomer components constituting the acrylic resin is preferably 40% by mass or more, more preferably 50% by mass or more, and still more preferably 60% by mass or more, relative to the total amount (100% by mass) of all the monomer components. The ratio is preferably 95% by mass or less, more preferably 80% by mass or less, from the viewpoint that the effect of the other monomer component can be obtained by copolymerizing the monomer component with the other monomer component.

The ratio of the alkyl (meth) acrylate having a linear or branched aliphatic hydrocarbon group in the total monomer components constituting the acrylic resin is preferably 30 mass% or more, more preferably 40 mass% or more, relative to the total amount (100 mass%) of the total monomer components. The ratio is preferably 90% by mass or less, more preferably 70% by mass or less.

The ratio of the (meth) acrylate having an alicyclic hydrocarbon group in the total monomer components constituting the acrylic resin is preferably 1% by mass or more, more preferably 5% by mass or more, relative to the total amount (100% by mass) of the total monomer components. The ratio is preferably 30% by mass or less, more preferably 20% by mass or less.

The acrylic resin may contain a structural unit derived from another monomer component copolymerizable with the hydrocarbon group-containing (meth) acrylate for the purpose of introducing the 1 st functional group described later and for the purpose of modifying the cohesive force, heat resistance, and the like. Examples of the other monomer component include monomers containing polar groups such as carboxyl group-containing monomers, acid anhydride monomers, hydroxyl group-containing monomers, glycidyl group-containing monomers, sulfonic acid group-containing monomers, phosphoric acid group-containing monomers, and nitrogen atom-containing monomers. The other monomer components may be used singly or in combination of two or more.

Examples of the carboxyl group-containing monomer include acrylic acid, methacrylic acid, carboxyethyl (meth) acrylate, carboxypentyl (meth) acrylate, itaconic acid, maleic acid, fumaric acid, and crotonic acid. Examples of the acid anhydride monomer include maleic anhydride and itaconic anhydride.

Examples of the hydroxyl group-containing monomer 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.

Examples of the glycidyl group-containing monomer include glycidyl (meth) acrylate and methyl glycidyl (meth) acrylate.

Examples of the sulfonic acid group-containing monomer include styrene sulfonic acid, allyl sulfonic acid, 2- (meth) acrylamide-2-methylpropanesulfonic acid, (meth) acrylamide propane sulfonic acid, sulfopropyl (meth) acrylate, and (meth) acryloxynaphthalene sulfonic acid.

Examples of the phosphate group-containing monomer include 2-hydroxyethyl acryloyl phosphate.

Examples of the nitrogen atom-containing monomer include morpholino-containing monomers such as (meth) acryloylmorpholine, cyano-containing monomers such as (meth) acrylonitrile, and amide-containing monomers such as (meth) acrylamide.

The polar group-containing monomer constituting the acrylic resin preferably contains a hydroxyl group-containing monomer. The hydroxyl group-containing monomer facilitates the introduction of the 1 st functional group described later. The acrylic resin and the resin layer are excellent in water resistance, and the optical semiconductor element sealing sheet is less likely to be hazed and excellent in whitening resistance even when used in an environment of high humidity.

The hydroxyl group-containing monomer is preferably 2-hydroxyethyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and more preferably 2-hydroxyethyl (meth) acrylate.

In order to properly exhibit basic properties such as adhesiveness due to the hydrocarbon group-containing (meth) acrylate and adhesiveness to the semiconductor element in the resin layer, the ratio of the polar group-containing monomer in the total monomer components (100 mass%) constituting the acrylic resin is preferably 5 to 50 mass%, more preferably 10 to 40 mass%. In particular, the ratio of the hydroxyl group-containing monomer is preferably within the above range from the viewpoint that the water resistance of the resin layer is also more excellent.

The other monomer component may further include a vinyl monomer such as a caprolactone adduct of (meth) acrylic acid, vinyl acetate, vinyl propionate, styrene, and α -methylstyrene; glycol-based acrylate monomers such as polyethylene glycol (meth) acrylate, polypropylene glycol (meth) acrylate, methoxyethylene glycol (meth) acrylate, and methoxypolypropylene glycol (meth) acrylate; tetrahydrofurfuryl (meth) acrylate, fluoro (meth) acrylate, silicone (meth) acrylate, alkoxy-substituted hydrocarbon group-containing (meth) acrylate (2-methoxyethyl (meth) acrylate, 3-phenoxybenzyl (meth) acrylate, and the like) acrylate monomers.

The ratio of the other monomer components in the total monomer components (100 mass%) constituting the acrylic resin may be, for example, about 3 to 50 mass%, or may be 5 to 40 mass% or 10 to 30 mass%.

The acrylic resin may contain a structural unit derived from a multifunctional (meth) acrylate copolymerizable with a monomer component constituting the acrylic resin in order to form a crosslinked structure in the polymer skeleton thereof. Examples of the polyfunctional (meth) acrylate include hexanediol di (meth) acrylate, (poly) ethylene glycol di (meth) acrylate, (poly) propylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, pentaerythritol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and the like. The polyfunctional monomer may be used alone or in combination of two or more.

In order to properly exhibit basic characteristics such as adhesiveness due to the hydrocarbon group-containing (meth) acrylate and adhesiveness to the semiconductor element in the resin layer, the ratio of the polyfunctional monomer in all monomer components (100 mass%) constituting the acrylic resin is preferably 40 mass% or less, more preferably 30 mass% or less.

When the resin layer is a radiation curable resin layer, examples of the resin layer include: a layer containing a radiation-polymerizable monomer component or oligomer component having a base polymer and a functional group such as a carbon-carbon double bond having radiation-polymerization property, a layer containing a polymer (particularly, an acrylic resin) having a radiation-polymerization functional group as a base polymer, and the like.

Examples of the radiation polymerizable functional group include a radiation radical polymerizable group such as a group containing a carbon-carbon unsaturated bond such as an ethylenically unsaturated group, a radiation cation polymerizable group, and the like. Examples of the group containing a carbon-carbon unsaturated bond include vinyl, propenyl, isopropenyl, acryl, and methacryl. Examples of the radiation cationically polymerizable group include an epoxy group, an oxetanyl group, and an oxetanyl group. Among them, a group containing a carbon-carbon unsaturated bond is preferable, and acryl and methacryl are more preferable. The radiation polymerizable functional group may be one kind or two or more kinds. The position of the radiation polymerizable functional group may be any of a polymer side chain, a polymer main chain, and a polymer main chain terminal.

The polymer having a radiation polymerizable functional group can be produced, for example, by a method in which a polymer having a reactive functional group (1 st functional group) and a compound having a functional group (2 nd functional group) capable of reacting with the 1 st functional group to form a bond are reacted and bonded in a state in which the radiation polymerization property of the radiation polymerizable functional group is maintained. Therefore, the polymer having a radiation polymerizable functional group preferably includes a structural portion derived from the polymer having the 1 st functional group and a structural portion derived from the compound having the 2 nd functional group and the radiation polymerizable functional group.

Examples of the combination of the 1 st functional group and the 2 nd functional group include a carboxyl group and an epoxy group, an epoxy group and a carboxyl group, a carboxyl group and an aziridine group, an aziridine group and a carboxyl group, a hydroxyl group and an isocyanate group, and an isocyanate group and a hydroxyl group. Among these, a combination of a hydroxyl group and an isocyanate group and a combination of an isocyanate group and a hydroxyl group are preferable from the viewpoint of ease of reaction tracking. The combination may be one kind or two or more kinds.

Examples of the compound having a radio-polymerizable functional group and an isocyanate group include methacryloyl isocyanate, 2-acryloyloxyethyl isocyanate, 2-methacryloyloxyethyl isocyanate (MOI), m-isopropenyl- α, α -dimethylbenzyl isocyanate, and the like. The above-mentioned compounds may be used singly or in combination of two or more.

The content of the structural portion derived from the compound having the 2 nd functional group and the radiation polymerizable functional group in the acrylic resin having the radiation polymerizable functional group is preferably 0.5 mol or more, more preferably 1 mol or more, still more preferably 3 mol or more, and still more preferably 10 mol or more, based on 100 mol of the total amount of the structural portion derived from the acrylic resin having the 1 st functional group, from the viewpoint of enabling further progress of curing of the radiation curable resin layer. The content is, for example, 100 mol or less.

The molar ratio of the 2 nd functional group to the 1 st functional group [ 2 nd functional group/1 st functional group ] in the acrylic resin having a radiation-polymerizable functional group is preferably 0.01 or more, more preferably 0.05 or more, still more preferably 0.2 or more, and particularly preferably 0.4 or more, from the viewpoint of enabling further progress of curing of the radiation-curable resin layer. In addition, from the viewpoint of further reducing the low molecular weight substance in the radiation curable resin layer, the above molar ratio is preferably less than 1.0, more preferably 0.9 or less.

The acrylic resin is obtained by polymerizing the 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, a polymerization method by irradiation of active energy rays (active energy ray polymerization method), and the like. The acrylic resin obtained is any of random copolymer, block copolymer, graft copolymer, and the like.

The acrylic resin having a radiation polymerizable functional group can be produced, for example, by the following method: after polymerizing (copolymerizing) a raw material monomer containing a monomer component having the 1 st functional group to obtain an acrylic resin having the 1 st functional group, a compound having the 2 nd functional group and the radiation polymerizable functional group is subjected to a condensation reaction or an addition reaction with the acrylic resin while maintaining the radiation polymerization property of the radiation polymerizable functional group.

In the polymerization of the monomer component, various general solvents can be used. Examples of the solvent include esters such as ethyl acetate and n-butyl acetate; aromatic hydrocarbons such as toluene and benzene; aliphatic hydrocarbons such as n-hexane and n-heptane; alicyclic hydrocarbons such as cyclohexane and methylcyclohexane; organic solvents such as ketones including methyl ethyl ketone and methyl isobutyl ketone. The solvent may be used alone or in combination of two or more.

The polymerization initiator, chain transfer agent, emulsifier, etc. used in the radical polymerization of the monomer component are not particularly limited, and may be appropriately selected and used. The weight average molecular weight of the acrylic polymer can be controlled by the amount of the polymerization initiator, the amount of the chain transfer agent, and the reaction conditions, and the amount thereof can be appropriately adjusted according to the kind of the polymerization initiator, the chain transfer agent, and the reaction conditions.

As the polymerization initiator used in the polymerization of the monomer component, a thermal polymerization initiator, a photopolymerization initiator (photoinitiator), or the like can be used depending on the kind of polymerization reaction. The polymerization initiator may be used alone or in combination of two or more.

The thermal polymerization initiator is not particularly limited, and examples thereof include azo-based polymerization initiators, peroxide-based polymerization initiators, redox-based polymerization initiators, and the like. The amount of the thermal polymerization initiator used is preferably 1 part by mass or less, more preferably 0.005 to 1 part by mass, and still more preferably 0.02 to 0.5 part by mass, based on 100 parts by mass of the total amount of all monomer components constituting the acrylic resin having the 1 st functional group.

Examples of the photopolymerization initiator include benzoin ether photopolymerization initiators, acetophenone photopolymerization initiators, α -ketol photopolymerization initiators, aromatic sulfonyl chloride photopolymerization initiators, photoactive oxime photopolymerization initiators, benzoin photopolymerization initiators, benzil photopolymerization initiators, benzophenone photopolymerization initiators, ketal photopolymerization initiators, thioxanthone photopolymerization initiators, acylphosphine oxide photopolymerization initiators, and titanocene photopolymerization initiators. Among them, acetophenone photopolymerization initiators are preferable.

Examples of the acetophenone photopolymerization initiator include 2, 2-diethoxyacetophenone, 2-dimethoxy-2-phenylacetophenone, 1-hydroxycyclohexylphenyl ketone, 4-phenoxydichloroacetophenone, 4- (tert-butyl) dichloroacetophenone, 1- [4- (2-hydroxyethoxy) -phenyl ] -2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, and methoxyacetophenone.

The amount of the photopolymerization initiator used is preferably 0.005 to 1 part by mass, more preferably 0.01 to 0.7 part by mass, and even more preferably 0.18 to 0.5 part by mass, based on 100 parts by mass of the total amount of all the monomer components constituting the acrylic resin. When the amount used is 0.005 parts by mass or more (particularly 0.18 parts by mass or more), the following tends to be the case: the molecular weight of the acrylic resin can be easily controlled to be small, and the residual stress of the resin layer becomes high, so that the level difference absorbability becomes more excellent.

The reaction of the acrylic resin having the 1 st functional group and the compound having the 2 nd functional group and the radiation polymerizable functional group may be carried out, for example, by stirring in a solvent in the presence of a catalyst. The solvent may be the solvent described above. The above-mentioned catalyst is appropriately selected according to the combination of the 1 st functional group and the 2 nd functional group. The reaction temperature in the above reaction is, for example, 5 to 100℃and the reaction time is, for example, 1 to 36 hours.

The acrylic resin may have a structural part derived from a crosslinking agent. For example, the acrylic resin can be crosslinked to further reduce the low molecular weight substance in the resin layer. In addition, the weight average molecular weight of the acrylic resin can be increased. When the acrylic resin has a radiation polymerizable functional group, the crosslinking agent is a substance that crosslinks functional groups other than the radiation polymerizable functional group (for example, the 1 st functional group, the 2 nd functional group, or the 1 st functional group and the 2 nd functional group). The crosslinking agent may be used alone or in combination of two or more.

Examples of the crosslinking agent include isocyanate-based crosslinking agents, epoxy-based crosslinking agents, melamine-based crosslinking agents, peroxide-based crosslinking agents, urea-based crosslinking agents, metal alkoxide-based crosslinking agents, metal chelate-based crosslinking agents, metal salt-based crosslinking agents, carbodiimide-based crosslinking agents, oxazoline-based crosslinking agents, aziridine-based crosslinking agents, amine-based crosslinking agents, silicone-based crosslinking agents, and silane-based crosslinking agents. Among these, isocyanate-based crosslinking agents and epoxy-based crosslinking agents are preferable, and isocyanate-based crosslinking agents are more preferable, from the viewpoint of excellent adhesion to the semiconductor element and low impurity ions.

Examples of the isocyanate-based crosslinking agent (polyfunctional isocyanate compound) include lower aliphatic polyisocyanates such as 1, 2-ethylene diisocyanate, 1, 4-butylene diisocyanate, and 1, 6-hexamethylene diisocyanate; alicyclic polyisocyanates such as cyclopentylene diisocyanate, cyclohexylene diisocyanate, isophorone diisocyanate, hydrogenated toluene diisocyanate, and hydrogenated xylene diisocyanate; aromatic polyisocyanates such as 2, 4-toluene diisocyanate, 2, 6-toluene diisocyanate, 4' -diphenylmethane diisocyanate, and xylylene diisocyanate. Examples of the isocyanate-based crosslinking agent include trimethylolpropane/toluene diisocyanate adduct, trimethylolpropane/hexamethylene diisocyanate adduct, and trimethylolpropane/xylylene diisocyanate adduct.

The content of the structural part derived from the crosslinking agent is not particularly limited, but is preferably 5 parts by mass or less, more preferably 0.001 to 5 parts by mass, and still more preferably 0.01 to 3 parts by mass, based on 100 parts by mass of the total amount of the acrylic resin excluding the structural part derived from the crosslinking agent.

The resin layer may contain components other than the above components in the colored layer, the diffusion functional layer, and the non-diffusion functional layer within a range that does not impair the effects of the present invention. Examples of the other components include crosslinking accelerators, tackifying resins (rosin derivatives, polyterpene resins, petroleum resins, oil-soluble phenols, and the like), oligomers, antioxidants, fillers (metal powders, organic fillers, inorganic fillers, and the like), antioxidants, plasticizers, softeners, surfactants, antistatic agents, surface lubricants, leveling agents, light stabilizers, ultraviolet absorbers, polymerization inhibitors, particulates, foils, and the like. The other components may be used alone or in combination of two or more.

The thickness of each layer of the first sealing layer, the second sealing layer and the third sealing layer is, for example, 5 to 480 μm. The thickness of the first sealing layer is preferably 5 to 100. Mu.m, more preferably 10 to 80. Mu.m, still more preferably 20 to 70. Mu.m. When the thickness of the first sealing layer is 5 μm or more, the sealing property of the semiconductor element becomes more excellent. When the thickness of the first sealing layer is 100 μm or less, it is easier to secure the luminance at the time of light emission of the optical semiconductor element.

The thickness of the second sealing layer is preferably 5 to 100. Mu.m, more preferably 10 to 80. Mu.m, still more preferably 20 to 70. Mu.m. When the thickness of the second sealing layer is 5 μm or more, the sealing property of the semiconductor element becomes more excellent. When the thickness of the second sealing layer is 100 μm or less, it is easier to secure the luminance at the time of light emission of the optical semiconductor element.

The thickness of the third sealing layer is preferably 30 to 480. Mu.m, more preferably 40 to 380. Mu.m, still more preferably 50 to 280. Mu.m. When the thickness of the third sealing layer is 30 μm or more, the sealing property of the semiconductor element becomes more excellent. When the thickness of the third sealing layer is 480 μm or less, chipping of the optical semiconductor element sealing sheet and adhesion of the sheet of the adjacent optical semiconductor device are less likely to occur when the adjacent optical semiconductor devices are pulled apart from each other in a flat state.

The thickness of the sealing portion (for example, a laminate having the first sealing layer and the third sealing layer on both end faces) is, for example, 100 to 500 μm, preferably 120 to 400 μm, and more preferably 150 to 300 μm. When the thickness is 100 μm or more, the sealing property of the optical semiconductor element becomes more excellent. When the thickness is 500 μm or less, the workability as a sheet and reworkability in the leveling step become more excellent, and side tackiness is less likely to occur.

The first sealing layer, the second sealing layer, and the third sealing layer when the resin layer is formed, for example, by the following method: after the resin composition for forming each layer is applied to the release treated surface of the release liner to form a resin composition layer, the resin composition layer is desolvated by heating and polymerized by irradiation with active energy rays, and if necessary, the resin composition layer is further heated to be cured.

The resin composition may be in any form. For example, when the resin layer is an adhesive layer, the resin composition (adhesive composition) may be emulsion type, solvent type (solution type), active energy ray-curable type, hot melt type (hot melt type) or the like. Among them, solvent-based and active energy ray-curable adhesive layers are preferable in terms of easy availability of adhesive layers excellent in productivity.

Examples of the resin composition include a resin composition containing a resin as an essential component, and a resin composition containing a mixture of monomers (monomer components) constituting the resin (sometimes referred to as "monomer mixture") or a partial polymer thereof as an essential component. The former includes, for example, a so-called solvent-type resin composition. The latter may be, for example, a so-called active energy ray-curable resin composition. The "monomer mixture" mentioned above means a mixture containing monomer components constituting a polymer. The term "partial polymer" is sometimes referred to as "prepolymer", "slurry", or the like, and refers to a composition in which 1 or 2 or more monomer components among the monomer components in the monomer mixture are partially polymerized.

The resin composition can be produced by a known and conventional method. For example, the solvent-based resin composition can be produced by mixing a colorant, light-diffusing fine particles, and other additives as necessary with a solution containing the above resin. For example, the active energy ray-curable resin composition can be produced by mixing an additive as necessary with a mixture of monomer components constituting the above resin or a partial polymer thereof.

The resin composition may be applied (coated) by a known coating method. For example, a gravure roll coater, a reverse roll coater, a roll lick coater, a dip roll coater, a bar coater, a blade coater, a spray coater, a comma coater, a direct coater, or the like can be used.

The solvent-based resin composition is preferably heated to a drying temperature of 40 to 200 ℃, more preferably 50 to 180 ℃, and even more preferably 70 to 170 ℃. The drying time may be suitably selected from, for example, 5 seconds to 20 minutes, preferably 5 seconds to 10 minutes, and more preferably 10 seconds to 5 minutes.

When the resin layer is formed by irradiation with active energy rays, the resin may be produced from the monomer component and the resin layer may be formed. The monomer component may be prepared by polymerizing a part of the monomer component in advance to form a slurry upon irradiation with active energy rays. The ultraviolet irradiation may be performed by a high-pressure mercury lamp, a low-pressure mercury lamp, a metal halide lamp, or the like.

(base material portion)

The substrate portion is a support for the sealing portion in the optical semiconductor element sealing sheet, and by providing the substrate portion, the optical semiconductor element sealing sheet is excellent in handleability. The base material portion may be a single layer or may be a plurality of layers having the same composition, different thickness, or the like. When the base material portion is a plurality of layers, the layers may be bonded by other layers such as an adhesive layer. The base material layer used in the base material portion is a portion that is bonded to the substrate provided with the optical semiconductor element together with the sealing portion when the optical semiconductor element is sealed with the optical semiconductor element sealing sheet, and the release liner that is peeled off when the optical semiconductor element sealing sheet is used (when bonded) and the surface protection film that is used only to protect the surface of the base material portion are not included in the "base material portion". The base material portion is laminated on the third sealing layer, for example.

Examples of the substrate layer constituting the substrate portion include glass, a plastic substrate (particularly, a plastic film), and the like. 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, homo-polypropylene, polybutene, polymethylpentene, ionomer, ethylene- (meth) acrylic acid copolymer, ethylene- (meth) acrylic acid ester (random, alternating) copolymer, ethylene-vinyl acetate copolymer (EVA), ethylene-propylene copolymer, cyclic olefin polymer, ethylene-butene copolymer, and ethylene-hexene copolymer; polyurethane; polyesters such as polyethylene terephthalate (PET), polyethylene naphthalate, polybutylene terephthalate (PBT), and the like; a polycarbonate; polyimide resin; polyether ether ketone; a polyetherimide; polyamides such as aramid and wholly aromatic polyamide; polyphenylene sulfide; a fluororesin; polyvinyl chloride; polyvinylidene chloride; cellulose resins such as triacetyl cellulose (TAC); a silicone resin; acrylic resins such as polymethyl methacrylate (PMMA); polysulfone; polyarylate; polyvinyl acetate, and the like. The resin may be used alone or in combination of two or more.

The base material layer may be various optical films such as an Antireflection (AR) film, a polarizing plate, and a retardation plate. When the base material portion has an optical film, the optical semiconductor element sealing sheet can be directly applied to an optical member.

The thickness of the plastic film is preferably 20 to 200. Mu.m, more preferably 40 to 150. Mu.m. When the thickness is 20 μm or more, the supporting property and handling property of the optical semiconductor element sealing sheet are further improved. When the thickness is 200 μm or less, the thickness of the optical semiconductor element sealing sheet can be reduced, and the optical semiconductor device can be made thinner.

For the purpose of improving the adhesion to the sealing portion, the holding property, and the like, the surface of the substrate portion on the side where the sealing portion is provided may be subjected to physical treatments such as corona discharge treatment, plasma treatment, blasting treatment, ozone exposure treatment, flame exposure treatment, high-voltage electric shock exposure treatment, and ionizing radiation treatment; chemical treatments such as chromic acid treatment; surface treatment such as easy adhesion treatment by a coating agent (primer). The surface treatment for improving the adhesion is preferably performed on the entire surface of the base material portion on the sealing portion side.

The thickness of the base material portion is preferably 5 μm or more, more preferably 10 μm or more, from the viewpoint of excellent functions as a support and scratch resistance of the surface. The thickness of the base material portion is preferably 300 μm or less, more preferably 200 μm or less, from the viewpoint of further excellent transparency.

(sheet for sealing optical semiconductor element)

The optical semiconductor element sealing sheet may include a layer having antiglare properties and/or antireflection properties. With such a configuration, when the optical semiconductor device is applied to a display, gloss and reflection of light of the display can be suppressed, and the display can be more attractive. The antiglare layer may be an antiglare layer. The antireflective layer may be an antireflective treatment layer. The antiglare treatment and the antireflection treatment can be carried out by known and conventional methods, respectively. The antiglare layer and the antireflection layer may be the same layer or may be different layers. The antiglare and/or antireflection layer may be provided in one layer or two or more layers.

The haze value (initial haze value) of the optical semiconductor element sealing sheet is not particularly limited, but is preferably 80% or more, more preferably 85% or more, still more preferably 90% or more, and particularly preferably 95% or more, from the viewpoint of making the effect of suppressing luminance unevenness and the appearance more excellent. The upper limit of the haze value is not particularly limited. When the optical semiconductor element sealing sheet includes a radiation curable resin layer, the haze value may be a value before curing or a value after curing of the radiation curable resin layer.

The total light transmittance of the optical semiconductor element sealing sheet is not particularly limited, but is preferably 30% or less, more preferably 20% or less, and even more preferably 5% or less, from the viewpoint of further improving the anti-reflection function and contrast of metal wiring and the like in the optical semiconductor device. In addition, from the viewpoint of ensuring the brightness of the optical semiconductor device, the total light transmittance is preferably 0.5% or more. When the optical semiconductor element sealing sheet includes a radiation curable resin layer, the total light transmittance may be a value before curing or a value after curing of the radiation curable resin layer.

The haze value and the total light transmittance of the optical semiconductor element sealing sheet can be measured by the methods defined in JIS K7136 and JIS K7361-1, respectively, and can be controlled by the order of lamination, the type, the thickness, and the like of the layers constituting the optical semiconductor element sealing sheet.

The optical semiconductor element sealing sheet has L measured from the third sealing layer side in a state where the first sealing layer is bonded to the aluminum foil ^* (SCI) and/or L ^* (SCE) is preferably 60 or less, more preferably less than 50, and still more preferably less than 40. When the light reflected by the object includes regular reflected light and diffuse reflected light, the regular reflected light is light that is difficult to recognize by naked eyes. L (L) ^* (SCE) is a value obtained by measuring reflected light not including regular reflected light, L ^* When (SCE) is 60 or less, the appearance is excellent when the image display apparatus is visually recognized. On the other hand, L ^* (SCI) is a value obtained by measuring reflected light including regular reflected light, and can measure a color tone similar to the true color tone of an object, although the correlation with visibility to the naked eye is low. Thus, L ^* When (SCI) is 60 or less, the visibility of the image display device is excellent even when the image display device is affected by the environment. In addition, L may be measured from the third seal layer side in a state where the first seal layer is bonded to the aluminum foil ^* (SCI) is called "L ^* (SCI) (1) ", L ^* (SCE) is called "L ^* (SCE)(1)”。L ^* (SCI) (1) and L ^* Specifically, (SCE) (1) can be measured by the method described in examples.

A convex sample having an aluminum foil on the surface thereof and having a length of 20mm by a width of 20mm by a thickness of 62 μm is placed on a substrate having a size larger than the convex sample, and the first sealing layer of the optical semiconductor element sealing sheet is formed so that the sheet covers the convex sampleL, as measured from the third sealing layer side in this state, bonded to the substrate and the convex sample ^* (SCI) and/or L ^* (SCE) is preferably 60 or less, more preferably less than 50, and still more preferably less than 40.L (L) ^* When (SCE) is 60 or less, the appearance is more excellent when the image display apparatus is visually recognized. L (L) ^* When (SCI) is 60 or less, the visibility of the image display device is more excellent even when the image display device is affected by the environment. In some cases, L is measured from the third seal layer side in a state where the first seal layer is bonded to the convex sample ^* (SCI) is called "L ^* (SCI) (2) ", L ^* (SCE) is called "L ^* (SCE)(2)”。L ^* (SCI) (2) and L ^* Specifically, (SCE) (2) can be measured by the method described in examples.

L of the optical semiconductor element sealing sheet ^* (SCI) (2) relative to L ^* Ratio of (SCI) (1) [ L ] ^* (SCI)(2)/L ^* (SCI)(1)]Preferably 1.2 or less, more preferably 1.1 or less, and still more preferably 1.05 or less. When the ratio is 1.2 or less, the appearance is excellent even when the difference in height due to the optical semiconductor element is high.

L of the optical semiconductor element sealing sheet ^* (SCE) (2) relative to L ^* Ratio of (SCE) (1) [ L ] ^* (SCE)(2)/L ^* (SCE)(1)]Preferably 1.2 or less, more preferably 1.1 or less, and still more preferably 1.05 or less. When the ratio is 1.2 or less, the appearance is excellent even when the difference in height due to the optical semiconductor element is high.

L ^* (SCI) and L ^* The closer the (SCE) is to 1, the more excellent the appearance. In the present specification, L ^* (SCI) and L ^* The (SCE) can be measured using a known conventional spectrocolorimeter. When the optical semiconductor element sealing sheet includes a radiation curable resin layer, it is preferable that the value of the radiation curable resin layer after curing is within the above range, because the value is measured in a state closer to the state when used. The value of the radiation curable resin layer before curing may be within the above range.

The diameter of the circle measured by the light diffusion effect confirmation test described below is preferably 5.0cm or more, more preferably 5.5cm or more, and even more preferably 6.0cm or more, using a measurement sample obtained by bonding the first sealing layer of the optical semiconductor element sealing sheet to a glass plate. When the diameter of the circular shape is 5.0cm or more, uneven brightness is further suppressed.

< light diffusion Effect confirmation test >

An LED lamp was provided on the screen, the glass plate was brought into close contact with the LED lamp, and when light was irradiated from the LED lamp onto the screen through the glass plate, the position where light having a circular shape with a diameter of 4.0cm appeared on the screen was set as the position of the LED lamp. Then, the diameter of the circular light that appears when light is irradiated from the LED lamp onto the screen through the glass plate and the optical semiconductor element sealing sheet is measured in a state where the LED lamp is in close contact with the glass plate side of the measurement sample obtained by bonding the first sealing layer of the optical semiconductor element sealing sheet to the glass plate.

The thickness of the optical semiconductor element sealing sheet of the present invention is preferably 10 to 600 μm, more preferably 20 to 550 μm, further preferably 30 to 500 μm, further preferably 40 to 450 μm, and particularly preferably 50 to 400 μm, from the viewpoint of improving the antireflection function and contrast of metal wiring and the like in an image display device and reducing color shift more efficiently. When the optical semiconductor element sealing sheet of the present invention includes the base material portion, the base material portion is included in the thickness of the optical semiconductor element sealing sheet of the present invention, but the release liner is not included in the thickness of the optical semiconductor element sealing sheet of the present invention.

[ Release liner ]

The release liner is a component for protecting the surface of the optical semiconductor element sealing sheet by coating the surface, and is peeled off from the optical semiconductor element sealing sheet when the sheet is bonded to a substrate on which the optical semiconductor element is disposed.

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

The thickness of the release liner is, for example, 10 to 200. Mu.m, preferably 15 to 150. Mu.m, more preferably 20 to 100. Mu.m. When the thickness is 10 μm or more, breakage due to slitting is less likely to occur during processing of the release liner. When the thickness is 200 μm or less, the release liner is more easily peeled from the optical semiconductor element sealing sheet at the time of use.

[ method for producing optical semiconductor element sealing sheet ]

An embodiment of a method for manufacturing an optical semiconductor element sealing sheet according to the present invention will be described. For example, as described above, for the optical semiconductor element sealing sheet 1 shown in fig. 1, the first sealing layer 21, the second sealing layer 22, and the third sealing layer 23 each sandwiched by the release treatment surfaces of 2 release liners are manufactured, for example. One release liner attached to the first sealing layer 21 is the release liner 3.

Then, one release liner attached to the third sealing layer 23 is peeled off to expose the surface of the third sealing layer 23, and the exposed surface is attached to the base material portion 4. Then, one release liner attached to the second seal layer 22 is peeled off, and the exposed surface of the second seal layer 22 is bonded to the surface of the third seal layer 23 exposed by peeling off the release liner on the surface of the third seal layer 23.

Next, one release liner (release liner other than release liner 3) attached to first seal layer 21 is peeled, and the exposed surface of first seal layer 21 is bonded to the surface of second seal layer 22 exposed by peeling the release liner on the surface of second seal layer 22. The lamination of the various layers may be performed using a known roll or laminator. In this way, the optical semiconductor element sealing sheet 1 shown in fig. 1 in which the third sealing layer 23, the second sealing layer 22, the first sealing layer 21, and the release liner 3 are laminated in this order on the base material portion 4 can be produced.

The optical semiconductor device can be obtained by bonding the first sealing layer to the substrate provided with the optical semiconductor element and sealing the optical semiconductor element using the optical semiconductor device sealing sheet of the present invention. Specifically, first, the release liner is peeled from the optical semiconductor element sealing sheet of the present invention to expose the first sealing layer. Then, the exposed surface of the optical semiconductor element sealing sheet of the present invention, that is, the first sealing layer surface is bonded to the substrate surface on which the optical semiconductor elements are arranged, the substrate and the optical member including the optical semiconductor elements (preferably, a plurality of optical semiconductor elements) arranged on the substrate. In this way, the optical semiconductor device can be sealed using the optical semiconductor device sealing sheet of the present invention. The sealing sheet for an optical semiconductor device of the present invention may be used to seal an optical semiconductor element in a reduced pressure environment or by bonding under pressure. Examples of such a method include the method disclosed in Japanese patent application laid-open No. 2016-29689 and Japanese patent application laid-open No. 6-97268.

[ optical semiconductor device ]

The optical semiconductor device can be manufactured using the optical semiconductor element sealing sheet of the present invention. An optical semiconductor device manufactured by using the optical semiconductor element sealing sheet of the present invention comprises: the optical semiconductor device sealing sheet of the present invention is a sheet for sealing an optical semiconductor device, which comprises a substrate, an optical semiconductor device disposed on the substrate, and the optical semiconductor device. In the case where the optical semiconductor element sealing sheet of the present invention includes a radiation curable resin layer, the cured product is a cured product obtained by curing the radiation curable resin layer by irradiation with radiation.

Examples of the 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.

In the above-described optical semiconductor device, the optical semiconductor element sealing sheet of the present invention is preferably sealed at one time because it has excellent following property for irregularities when the optical semiconductor element is a convex portion and gaps between the plurality of optical semiconductor elements are concave portions, and excellent following property and landfill property of the optical semiconductor element.

Fig. 2 shows an embodiment of an optical semiconductor device using the optical semiconductor element sealing sheet 1 shown in fig. 1. The optical semiconductor device 10 shown in fig. 2 includes: a substrate 5, a plurality of optical semiconductor elements 6 arranged on one surface of the substrate 5, and an optical semiconductor element sealing sheet 1 for sealing the optical semiconductor elements 6. The optical semiconductor element sealing sheet 1 is obtained by peeling the release liner 3 from the optical semiconductor element sealing sheet 1 shown in fig. 1. The plurality of optical semiconductor elements 6 are sealed by the sealing portion at one time. The first sealing layer 21 adheres to the optical semiconductor element 6 and the substrate 5 in accordance with the concave-convex shape formed by the plurality of optical semiconductor elements 6, and fills the optical semiconductor element 6.

In the optical semiconductor device 10 shown in fig. 2, the optical semiconductor element 6 is completely embedded in the first sealing layer 21 and sealed, and is indirectly sealed by the second sealing layer 22 and the third sealing layer 23. That is, the optical semiconductor element 6 is sealed by the sealing portion 2 formed of the laminate of the first sealing layer 21, the second sealing layer 22, and the third sealing layer 23. The optical semiconductor device is not limited to this embodiment, and may be as follows: a part of the optical semiconductor element 6 protrudes from the first sealing layer 21, and is buried in the second sealing layer 22, or the second and third sealing layers 22 and 23, and the optical semiconductor element 6 is completely buried and sealed by the first and second sealing layers 21 and 22, or by the first, second and third sealing layers 21, 22 and 23.

The optical semiconductor device may be a device in which the respective optical semiconductor devices are tiled. That is, the optical semiconductor device may be a device in which a plurality of optical semiconductor devices are arranged in a tile shape in a planar direction.

Fig. 3 shows an embodiment of an optical semiconductor device manufactured by disposing a plurality of optical semiconductor devices. The optical semiconductor device 20 shown in fig. 3 is formed by arranging (tiling) a total of 16 optical semiconductor devices 10, which are 4 in the longitudinal direction and 4 in the lateral direction, in a tile shape in the planar direction. At the boundary 20a between the adjacent 2 optical semiconductor devices 10, the optical semiconductor devices 10 are adjacent to each other.

The optical semiconductor device is preferably a backlight for a liquid crystal display, and particularly preferably a backlight for a full-face direct type. In addition, an image display device can be manufactured by combining the backlight described above with a display panel. The optical semiconductor device is an LED device when the optical semiconductor device is a backlight of a liquid crystal display. For example, in the backlight, a metal wiring layer for supplying a light emission control signal to each LED element is laminated on the substrate. The LED elements that emit light of red (R), green (G), and blue (B) are alternately arranged on the substrate of the display panel through metal wiring layers. The metal wiring layer is made of a metal such as copper, and reflects the light emitted from each LED element, thereby reducing the visibility of the image. In addition, color mixing of light emitted from each LED element of each color of RGB occurs, and contrast is lowered.

The optical semiconductor device is preferably a self-light-emitting display device. In addition, the self-luminous display device can be combined with a display panel according to need to produce an image display device. When the above-mentioned optical semiconductor device is a self-luminous display device, the optical semiconductor element is an LED element. Examples of the self-luminous display device include an organic electroluminescence (organic EL) display device and the backlight. For example, in the self-luminous display device, a metal wiring layer for transmitting a light emission control signal to each LED element is laminated on the substrate. The LED elements that emit light of red (R), green (G), and blue (B) are alternately arranged on the substrate with a metal wiring layer interposed therebetween. The metal wiring layer is made of a metal such as copper, and displays each color by adjusting the light emission degree of each LED element.

The optical semiconductor element sealing sheet of the present invention can be used for an optical semiconductor device which can be used for bending, for example, an optical semiconductor device having a bendable image display device (flexible display) (particularly, a foldable image display device (foldable display)). Specifically, the present invention can be used for a foldable backlight, a foldable self-luminous display device, and the like.

The optical semiconductor element sealing sheet of the present invention is excellent in the following property and landfill property of the optical semiconductor element, and therefore can be preferably used both in the case where the optical semiconductor device is a mini LED display device and in the case where the optical semiconductor device is a micro LED display device.

[ method for manufacturing optical semiconductor device ]

The optical semiconductor device can be manufactured, for example, by a manufacturing method including at least a dicing step in which a laminate is diced to obtain an optical semiconductor device, the laminate including: the optical semiconductor device sealing sheet of the present invention is a cured product obtained by curing a substrate, an optical semiconductor device disposed on the substrate, and an optical semiconductor device sealing sheet or a radiation curable resin layer. The cured product is a cured product obtained by curing the optical semiconductor element sealing sheet of the present invention by irradiation with radiation, and specifically, a cured product obtained by curing the radiation curable resin layer that the optical semiconductor element sealing sheet of the present invention can have by irradiation with radiation.

The above-described production method may further include a radiation irradiation step of: and curing the radiation curable resin layer by irradiating a laminate with radiation to obtain the cured product, wherein the laminate comprises: the substrate, an optical semiconductor element disposed on the substrate, and the optical semiconductor element sealing sheet for sealing the optical semiconductor element.

The above-described production method may include the following sealing step before the radiation irradiation step: the optical semiconductor element sealing sheet is bonded to the optical semiconductor element provided on the substrate, and the optical semiconductor element is sealed by the sealing portion.

The above manufacturing method may further include a tiling step of: the plurality of optical semiconductor devices obtained in the dicing step are arranged so as to be in contact with each other in the planar direction. Hereinafter, description will be given with appropriate reference to the method of manufacturing the optical semiconductor device 10 shown in fig. 2 and the optical semiconductor device 20 shown in fig. 3.

(sealing Process)

In the sealing step, the optical semiconductor element sealing sheet of the present invention is bonded to the substrate on which the optical semiconductor element is disposed, and the optical semiconductor element is sealed by the sealing portion. Specifically, in the sealing step, as shown in fig. 4, the first sealing layer 21 of the optical semiconductor element sealing sheet 1 from which the release liner 3 is peeled is disposed so as to face the surface of the substrate 5 on which the optical semiconductor element 6 is disposed, and the optical semiconductor element sealing sheet 1 is bonded to the surface of the substrate 5 on which the optical semiconductor element 6 is disposed, and as shown in fig. 5, the optical semiconductor element 6 is buried in the sealing portion 2.

When the optical semiconductor element sealing sheet 1 includes a radiation-curable resin layer, as shown in fig. 4, the substrate 5 used for bonding extends wider in the planar direction than the substrate 5 in the optical semiconductor device 10 shown in fig. 2, and the optical semiconductor element 6 is not disposed near the end of the substrate 5. In this case, the bonded optical semiconductor element sealing sheet 1 extends wider in the planar direction than the substrate 5 used for bonding. That is, the area of the surface of the optical semiconductor element sealing sheet 1 bonded in the sealing step facing the substrate 5 is larger than the area of the surface of the substrate 5 bonded in the sealing step facing the optical semiconductor element sealing sheet 1. This is because: in the laminate of the optical semiconductor element sealing sheet 1 and the substrate 5, the region for the optical semiconductor device is sufficiently cured in the subsequent irradiation step, and the vicinity of the end portion of the optical semiconductor element sealing sheet 1 and the substrate 5, which may be insufficiently cured, may be cut and removed in the subsequent dicing step.

The temperature at the time of bonding is, for example, in the range of room temperature to 110 ℃. In addition, the pressure may be reduced or increased during the bonding. By the decompression and pressurization, formation of a void between the sealing portion and the substrate or the optical semiconductor element can be suppressed. In the sealing step, it is preferable that the optical semiconductor element sealing sheet is bonded under reduced pressure and then pressurized. The pressure at the time of depressurization is, for example, 1 to 100Pa, and the depressurization time is, for example, 5 to 600 seconds. The pressure at the time of pressurization is, for example, 0.05 to 0.5MPa, and the pressure reduction time is, for example, 5 to 600 seconds.

(radiation irradiation step)

In the radiation irradiation step, the radiation curable resin layer is cured by irradiating a laminate (for example, a laminate obtained in the sealing step) obtained by bonding the optical semiconductor element sealing sheet to the substrate on which the optical semiconductor element is arranged with radiation. Examples of the radiation include electron beam, ultraviolet ray, α ray, β ray, γ ray, and X ray, as described above. Among them, ultraviolet rays are preferable. The temperature at the time of irradiation with the radiation is, for example, in the range of room temperature to 100℃and the irradiation time is, for example, 1 minute to 1 hour.

(cutting step)

In the dicing step, a laminate is diced, the laminate including: the optical semiconductor device sealing sheet of the present invention is a cured product obtained by curing a substrate, an optical semiconductor device disposed on the substrate, and an optical semiconductor device sealing sheet or a radiation curable resin layer. Here, when the laminate includes the cured product, the cured product of the optical semiconductor element sealing sheet and the substrate 5 in the laminate to be subjected to the dicing step extend wider in the planar direction than the finally obtained optical semiconductor device 10 as described above. In the dicing step, the cured product of the optical semiconductor element sealing sheet and the side end portion of the substrate are diced and removed. Specifically, the side end portions are removed by cutting at the positions of the broken lines shown in fig. 6. The cutting may be performed by a known and conventional method, for example, by a method using a cutting blade or by irradiation with a laser. In this way, for example, the optical semiconductor device 10 shown in fig. 2 can be manufactured.

(tiling step)

In the tiling step, the plurality of optical semiconductor devices obtained in the dicing step are arranged so as to be in contact with each other in the planar direction, and are tiled. In this way, for example, the optical semiconductor device 20 shown in fig. 3 can be manufactured.

Examples

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.

Production example 1

(production of non-diffusion functional layer 1)

67 parts by mass of Butyl Acrylate (BA), 14 parts by mass of cyclohexyl acrylate (CHA), 27 parts by mass of 4-hydroxybutyl acrylate (4 HBA), 9 parts by mass of 2-hydroxyethyl acrylate (HEA), 0.05 part by mass of 2, 2-dimethoxy-1, 2-diphenyl-1-one (trade name "omnirad 651", manufactured by IGM Resins Italia Srl Co.) and 0.05 part by mass of 1-hydroxy-cyclohexyl-phenyl-one (trade name "omnirad 184", manufactured by IGM Resins Italia Srl Co.) were charged into a four-necked flask, and a partial photopolymerization was carried out by exposure to ultraviolet rays under a nitrogen atmosphere, thereby obtaining a partial polymer (monomer slurry) having a polymerization rate of 10%. To 100 parts by mass of the partial polymer, 1.5 parts by mass of an isocyanate compound (trade name "TAKENATE D-101A", manufactured by Mitsui chemical Co., ltd., solid content 75% by mass) in terms of solid content was added, and then the mixture was uniformly mixed to prepare a photopolymerizable composition.

The photopolymerizable composition was applied to a release-treated surface of a release liner (trade name "MRA50", manufactured by Mitsubishi chemical corporation, a release treatment was applied to one side of a polyethylene terephthalate film, and the thickness was 50 μm) to form a resin composition layer, and then the release-treated surface of the release liner (trade name "MRF38", manufactured by Mitsubishi chemical corporation) was also bonded to the resin composition layer. Next, the irradiation intensity with black light was 5mW/cm ² Ultraviolet polymerization was carried out until the cumulative light amount was 3600mJ/cm ² A non-diffusion functional layer 1 was produced as an adhesive layer.

Production example 2

(production of colored layer 1)

67 parts by mass of Butyl Acrylate (BA), 14 parts by mass of cyclohexyl acrylate (CHA), 27 parts by mass of 4-hydroxybutyl acrylate (4 HBA), 9 parts by mass of 2-hydroxyethyl acrylate (HEA), 0.05 part by mass of 2, 2-dimethoxy-1, 2-diphenyl-1-one (trade name "omnirad 651", manufactured by IGM Resins Italia Srl Co.) and 0.05 part by mass of 1-hydroxy-cyclohexyl-phenyl-one (trade name "omnirad 184", manufactured by IGM Resins Italia Srl Co.) were charged into a four-necked flask, and a partial photopolymerization was carried out by exposure to ultraviolet rays under a nitrogen atmosphere, thereby obtaining a partial polymer (monomer slurry) having a polymerization rate of 10%. To 100 parts by mass of this partial polymer, 0.1 part by mass of an isocyanate compound (trade name "TAKENATE D-101A", manufactured by Mitsui chemical Co., ltd., solid content 75% by mass) and 9.2 parts by mass of a Black pigment dispersion (trade name "9050Black", manufactured by TOKUSHIKICO., ltd.) in terms of solid content were added, and these were uniformly mixed to prepare a photopolymerizable composition.

The photopolymerizable composition was applied to a release-treated surface of a release liner (trade name "MRA50", manufactured by Mitsubishi chemical corporation, a release treatment was applied to one side of a polyethylene terephthalate film, and the thickness was 50 μm) to form a resin composition layer, and then the release-treated surface of the release liner (trade name "MRF38", manufactured by Mitsubishi chemical corporation) was also bonded to the resin composition layer. Next, the irradiation intensity with black light was 5mW/cm ² Ultraviolet polymerization was carried out until the cumulative light amount was 3600mJ/cm ² A colored layer 1 was produced as an adhesive layer.

Production example 3

(production of diffusion functional layer 1)

67 parts by mass of Butyl Acrylate (BA), 14 parts by mass of cyclohexyl acrylate (CHA), 27 parts by mass of 4-hydroxybutyl acrylate (4 HBA), 9 parts by mass of 2-hydroxyethyl acrylate (HEA), 0.05 part by mass of 2, 2-dimethoxy-1, 2-diphenyl-1-one (trade name "omnirad 651", manufactured by IGM Resins Italia Srl Co.) and 0.05 part by mass of 1-hydroxy-cyclohexyl-phenyl-one (trade name "omnirad 184", manufactured by IGM Resins Italia Srl Co.) were charged into a four-necked flask, and a partial photopolymerization was carried out by exposure to ultraviolet rays under a nitrogen atmosphere, thereby obtaining a partial polymer (monomer slurry) having a polymerization rate of 10%. To 100 parts by mass of this partial polymer, 0.1 part by mass of an isocyanate compound (trade name "TAKENATE D-101A", manufactured by Mitsui chemical Co., ltd., solid content 75% by mass) and 3 parts by mass of titanium oxide (trade name "Tipure R706", manufactured by DuPont Co., ltd., refractive index: about 2.5, average particle diameter: 0.36 μm) in terms of solid content were added, and these were uniformly mixed to prepare a photopolymerizable composition.

The photopolymerizable composition was applied to a release-treated surface of a release liner (trade name "MRA50", manufactured by Mitsubishi chemical corporation, a release treatment was applied to one side of a polyethylene terephthalate film, and the thickness was 50 μm) to form a resin composition layer, and then the release-treated surface of the release liner (trade name "MRF38", manufactured by Mitsubishi chemical corporation) was also bonded to the resin composition layer. Next, the irradiation intensity with black light was 5mW/cm ² Ultraviolet polymerization was carried out until the cumulative light amount was 3600mJ/cm ² A diffusion functional layer 1 was produced as an adhesive layer.

Production example 4

(preparation of diffusion functional layer 2)

67 parts by mass of Butyl Acrylate (BA), 14 parts by mass of cyclohexyl acrylate (CHA), 27 parts by mass of 4-hydroxybutyl acrylate (4 HBA), 9 parts by mass of 2-hydroxyethyl acrylate (HEA), 0.05 part by mass of 2, 2-dimethoxy-1, 2-diphenyl-1-one (trade name "omnirad 651", manufactured by IGM Resins Italia Srl Co.) and 0.05 part by mass of 1-hydroxy-cyclohexyl-phenyl-one (trade name "omnirad 184", manufactured by IGM Resins Italia Srl Co.) were charged into a four-necked flask, and a partial photopolymerization was carried out by exposure to ultraviolet rays under a nitrogen atmosphere, thereby obtaining a partial polymer (monomer slurry) having a polymerization rate of 10%. To 100 parts by mass of this partial polymer, 1.5 parts by mass of an isocyanate compound (trade name "TAKENATE D-101A", manufactured by Mitsui chemical Co., ltd., solid content 75% by mass) and 3 parts by mass of titanium oxide (trade name "Tipure R706", manufactured by DuPont Co., ltd., refractive index: about 2.5, average particle diameter: 0.36 μm) in terms of solid content were added, and these were uniformly mixed to prepare a photopolymerizable composition.

The photopolymerizable composition was applied to a release liner (trade nameAfter a resin composition layer was formed on a release treated surface of a polyethylene terephthalate film, which was subjected to a release treatment and had a thickness of 50 μm, from Mitsubishi chemical corporation, MRA50, a release treated surface of a release liner (trade name "MRF38", from Mitsubishi chemical corporation) was also bonded to the resin composition layer. Next, the irradiation intensity with black light was 5mW/cm ² Ultraviolet polymerization was carried out until the cumulative light amount was 3600mJ/cm ² A diffusion functional layer 2 was produced as an adhesive layer.

Production example 5

(production of non-diffusion functional layer 2)

67 parts by mass of Butyl Acrylate (BA), 14 parts by mass of cyclohexyl acrylate (CHA), 27 parts by mass of 4-hydroxybutyl acrylate (4 HBA), 9 parts by mass of 2-hydroxyethyl acrylate (HEA), 0.05 part by mass of 2, 2-dimethoxy-1, 2-diphenyl-1-one (trade name "omnirad 651", manufactured by IGM Resins Italia Srl Co.) and 0.05 part by mass of 1-hydroxy-cyclohexyl-phenyl-one (trade name "omnirad 184", manufactured by IGM Resins Italia Srl Co.) were charged into a four-necked flask, and a partial photopolymerization was carried out by exposure to ultraviolet rays under a nitrogen atmosphere, thereby obtaining a partial polymer (monomer slurry) having a polymerization rate of 10%. To 100 parts by mass of the partial polymer, 0.1 part by mass of an isocyanate compound (trade name "TAKENATE D-101A", manufactured by Mitsui chemical Co., ltd., solid content 75% by mass) in terms of solid content was added, and then the mixture was uniformly mixed to prepare a photopolymerizable composition.

The photopolymerizable composition was applied to a release-treated surface of a release liner (trade name "MRA50", manufactured by Mitsubishi chemical corporation, a release treatment was applied to one side of a polyethylene terephthalate film, and the thickness was 50 μm) to form a resin composition layer, and then the release-treated surface of the release liner (trade name "MRF38", manufactured by Mitsubishi chemical corporation) was also bonded to the resin composition layer. Next, the irradiation intensity with black light was 5mW/cm ² Ultraviolet polymerization was carried out until the cumulative light amount was 3600mJ/cm ² A non-diffusion functional layer 2 was produced as an adhesive layer.

Production example 6

(preparation of diffusion functional layer 3)

67 parts by mass of Butyl Acrylate (BA), 14 parts by mass of cyclohexyl acrylate (CHA), 27 parts by mass of 4-hydroxybutyl acrylate (4 HBA), 9 parts by mass of 2-hydroxyethyl acrylate (HEA), 0.05 part by mass of 2, 2-dimethoxy-1, 2-diphenyl-1-one (trade name "omnirad651", manufactured by IGM Resins Italia Srl Co.) and 0.05 part by mass of 1-hydroxy-cyclohexyl-phenyl-one (trade name "omnirad 184", manufactured by IGM Resins Italia Srl Co.) were charged into a four-necked flask, and a partial photopolymerization was carried out by exposure to ultraviolet rays under a nitrogen atmosphere, thereby obtaining a partial polymer (monomer slurry) having a polymerization rate of 10%. To 83 parts by mass of this partial polymer, 1.2 parts by mass of an isocyanate compound (trade name "TAKENATE D-101A", manufactured by Mitsui chemical Co., ltd., solid content 75% by mass), 30 parts by mass of ase:Sub>A silicone resin (trade name "Tospearl 145", manufactured by Momentive Performance Materials Japan, refractive index: 1.42, average particle diameter: 4.5 μm), 16 parts by mass of 3-phenoxybenzyl acrylate (trade name "LIGHT ACRYLATE POB-A", manufactured by co-Rong chemical Co., ltd.) and 1 part by mass of trade name "Omnirad651" were added in terms of solid content, and these were uniformly mixed to prepare ase:Sub>A photopolymerizable composition.

The photopolymerizable composition was applied to a release-treated surface of a release liner (trade name "MRA50", manufactured by Mitsubishi chemical corporation, a release treatment was applied to one side of a polyethylene terephthalate film, and the thickness was 50 μm) to form a resin composition layer, and then the release-treated surface of the release liner (trade name "MRF38", manufactured by Mitsubishi chemical corporation) was also bonded to the resin composition layer. Next, the irradiation intensity with black light was 5mW/cm ² Ultraviolet polymerization was carried out until the cumulative light amount was 3600mJ/cm ² A diffusion functional layer 3 was produced as an adhesive layer.

PREPARATION EXAMPLE 7

(production of colored layer 2)

67 parts by mass of Butyl Acrylate (BA), 14 parts by mass of cyclohexyl acrylate (CHA), 27 parts by mass of 4-hydroxybutyl acrylate (4 HBA), 9 parts by mass of 2-hydroxyethyl acrylate (HEA), 0.05 part by mass of 2, 2-dimethoxy-1, 2-diphenyl-1-one (trade name "omnirad 651", manufactured by IGM Resins Italia Srl Co.) and 0.05 part by mass of 1-hydroxy-cyclohexyl-phenyl-one (trade name "omnirad 184", manufactured by IGM Resins Italia Srl Co.) were charged into a four-necked flask, and a partial photopolymerization was carried out by exposure to ultraviolet rays under a nitrogen atmosphere, thereby obtaining a partial polymer (monomer slurry) having a polymerization rate of 10%. To 100 parts by mass of this partial polymer, 1.2 parts by mass of an isocyanate compound (trade name "TAKENATE D-101A", manufactured by Mitsui chemical Co., ltd., solid content 75% by mass) and 9.2 parts by mass of a Black pigment dispersion (trade name "9050Black", manufactured by TOKUSHIKICO., ltd.) in terms of solid content were added, and these were uniformly mixed to prepare a photopolymerizable composition.

The photopolymerizable composition was applied to a release-treated surface of a release liner (trade name "MRA50", manufactured by Mitsubishi chemical corporation, a release treatment was applied to one side of a polyethylene terephthalate film, and the thickness was 50 μm) to form a resin composition layer, and then the release-treated surface of the release liner (trade name "MRF38", manufactured by Mitsubishi chemical corporation) was also bonded to the resin composition layer. Next, the irradiation intensity with black light was 5mW/cm ² Ultraviolet polymerization was carried out until the cumulative light amount was 3600mJ/cm ² A colored layer 2 was produced as an adhesive layer.

Production example 8

(preparation of diffusion functional layer 4)

67 parts by mass of Butyl Acrylate (BA), 14 parts by mass of cyclohexyl acrylate (CHA), 27 parts by mass of 4-hydroxybutyl acrylate (4 HBA), 9 parts by mass of 2-hydroxyethyl acrylate (HEA), 0.05 part by mass of 2, 2-dimethoxy-1, 2-diphenyl-1-one (trade name "omnirad651", manufactured by IGM Resins Italia Srl Co.) and 0.05 part by mass of 1-hydroxy-cyclohexyl-phenyl-one (trade name "omnirad 184", manufactured by IGM Resins Italia Srl Co.) were charged into a four-necked flask, and a partial photopolymerization was carried out by exposure to ultraviolet rays under a nitrogen atmosphere, thereby obtaining a partial polymer (monomer slurry) having a polymerization rate of 10%. To 83 parts by mass of this partial polymer, 0.08 parts by mass of an isocyanate compound (trade name "TAKENATE D-101A", manufactured by Mitsui chemical Co., ltd., solid content 75% by mass), 30 parts by mass of ase:Sub>A silicone resin (trade name "Tospearl 145", manufactured by Momentive Performance Materials Japan, refractive index: 1.42, average particle diameter: 4.5 μm), 16 parts by mass of 3-phenoxybenzyl acrylate (trade name "LIGHT ACRYLATE POB-A", manufactured by co-Rong chemical Co., ltd.) and 1 part by mass of trade name "Omnirad651" were added in terms of solid content, and these were uniformly mixed to prepare ase:Sub>A photopolymerizable composition.

The photopolymerizable composition was applied to a release-treated surface of a release liner (trade name "MRA50", manufactured by Mitsubishi chemical corporation, a release treatment was applied to one side of a polyethylene terephthalate film, and the thickness was 50 μm) to form a resin composition layer, and then the release-treated surface of the release liner (trade name "MRF38", manufactured by Mitsubishi chemical corporation) was also bonded to the resin composition layer. Next, the irradiation intensity with black light was 5mW/cm ² Ultraviolet polymerization was carried out until the cumulative light amount was 3600mJ/cm ² A diffusion functional layer 4 was produced as an adhesive layer.

Production example 9

(production of non-diffusion functional layer 3 having ultraviolet curability)

189.77 parts by mass of Butyl Acrylate (BA), 38.04 parts by mass of cyclohexyl acrylate (CHA), 85.93 parts by mass of 2-hydroxyethyl acrylate (HEA), 0.94 part by mass of 2,2' -azobisisobutyronitrile as a polymerization initiator, and 379.31 parts by mass of methyl ethyl ketone as a polymerization solvent were charged into an experimental apparatus for polymerization equipped with a removable cap, a separating funnel, a thermometer, a nitrogen introducing tube, a Libish condenser, a vacuum seal, a stirring rod, and a stirring blade on a 1L round bottom removable flask, and nitrogen substitution was performed at normal temperature for 6 hours while stirring. Then, polymerization was carried out under stirring at 65℃for 4 hours and then at 75℃for 2 hours while flowing nitrogen gas, to obtain a resin solution.

Then, the obtained resin solution was cooled to room temperature. Then, 5.74 parts by mass of 2-isocyanatoethyl Methacrylate (MOI) (trade name "Karenz MOI", manufactured by Showa electric Co., ltd.) as a compound having a polymerizable carbon-carbon double bond was added to the resin solution. Further, 0.03 parts by mass of dibutyltin (IV) dilaurate (manufactured by Fuji photo-pure chemical Co., ltd.) was added, and the mixture was stirred at 50℃for 24 hours under an air atmosphere to obtain a base polymer.

1.5 parts by mass of an isocyanate compound (trade name "TAKENATE D-101A", manufactured by Mitsui chemical Co., ltd., solid content 75% by mass) and 1 part by mass of 2, 2-dimethoxy-1, 2-diphenyl-1-one (trade name "omnirad 651", manufactured by IGM Resins Italia Srl company) were mixed with respect to 100 parts by mass of the solid content of the obtained base polymer. Toluene was used as a diluting solvent, and the solid content was adjusted to 20 to 40 mass%, to obtain a binder solution.

The adhesive solution was applied to a treated surface of a release liner (trade name "MRA50", manufactured by Mitsubishi chemical corporation, which had been subjected to a release treatment on one side of a polyethylene terephthalate film and had a thickness of 50 μm) so that the thickness of the adhesive solution after drying was 50. Mu.m, and the treated surface was dried by heating at 50℃for 1 minute and 125℃for 5 minutes under normal pressure to form a resin layer. Then, a release-treated surface of a release liner (trade name "MRF38", manufactured by Mitsubishi chemical corporation) was bonded to the surface of the resin layer. Then, heating was applied at 50℃for 48 hours under light shielding, to produce a non-diffusion functional layer 3 having ultraviolet curability as an adhesive layer.

Example 1

(production of optical semiconductor element sealing sheet)

The non-diffusion functional layer 1 obtained in production example 1 was peeled off a release liner (trade name "MRF 38") to expose the adhesive surface. The exposed surface of the non-diffusion functional layer 1 was bonded to an adhesion-facilitating surface of a base film (trade name "Diafoil T912E75 (UE 80-)", manufactured by Mitsubishi chemical corporation, in which an adhesion-facilitating treatment was applied to one surface of a polyethylene terephthalate film, and the thickness was 75 μm), and a third sealing layer formed of the non-diffusion functional layer 1 was formed on the base film.

Next, the release liner (trade name "MRA 50") was peeled off from the surface of the third sealing layer (non-diffusion functional layer 1) to expose the adhesive surface. An exposed adhesive surface of the release liner (trade name "MRF 38") obtained from the colored layer 1 obtained in production example 2 was peeled off and adhered to the exposed surface of the third sealing layer, and a second sealing layer formed of the colored layer 1 was formed on the third sealing layer.

Then, the release liner (trade name "MRA 50") was peeled off from the surface of the second sealing layer (colored layer 1) to make the adhesive surface. An exposed adhesive surface of the release liner (trade name "MRF 38") obtained from production example 3 was peeled off from the diffusion functional layer 1 and adhered to the exposed surface of the second sealing layer, and a first sealing layer formed of the diffusion functional layer 1 was formed on the second sealing layer.

Then, the resultant was bonded with a manual roller at room temperature (23 ℃) so as not to mix air bubbles, and left under light shielding for two days. Thus, an optical semiconductor element sealing sheet formed of [ release liner/diffusion functional layer 1/colored layer 1/non-diffusion functional layer 1/base film ] was obtained.

Examples 2 to 8 and comparative examples 1 to 2

(production of optical semiconductor element sealing sheet)

An optical semiconductor element sealing sheet was obtained in the same manner as in example 1 except that the layers shown in table 1 or 2 were formed as the first sealing layer, the second sealing layer, and the third sealing layer.

Comparative example 3

(production of colored layer 3)

67 parts by mass of Butyl Acrylate (BA), 14 parts by mass of cyclohexyl acrylate (CHA), 27 parts by mass of 4-hydroxybutyl acrylate (4 HBA), 9 parts by mass of 2-hydroxyethyl acrylate (HEA), 0.05 part by mass of 2, 2-dimethoxy-1, 2-diphenyl-1-one (trade name "omnirad 651", manufactured by IGM Resins Italia Srl Co.) and 0.05 part by mass of 1-hydroxy-cyclohexyl-phenyl-one (trade name "omnirad 184", manufactured by IGM Resins Italia Srl Co.) were charged into a four-necked flask, and a partial photopolymerization was carried out by exposure to ultraviolet rays under a nitrogen atmosphere, thereby obtaining a partial polymer (monomer slurry) having a polymerization rate of 10%. To 100 parts by mass of this partial polymer, 0.1 part by mass of an isocyanate compound (trade name "TAKENATE D-101A", manufactured by Mitsui chemical Co., ltd., solid content 75% by mass) and 2 parts by mass of a Black pigment dispersion (trade name "9050Black", manufactured by TOKUSHIKICO., ltd.) in terms of solid content were added, and these were uniformly mixed to prepare a photopolymerizable composition.

Will be put onThe photopolymerizable composition was applied to a release-treated surface of a release liner (trade name "MRA50", manufactured by Mitsubishi chemical corporation, a release treatment was applied to one side of a polyethylene terephthalate film, and the thickness was 50 μm) to form a resin composition layer, and then the release-treated surface of the release liner (trade name "MRF38", manufactured by Mitsubishi chemical corporation) was also bonded to the resin composition layer. Next, the irradiation intensity with black light was 5mW/cm ² Ultraviolet polymerization was carried out until the cumulative light amount was 3600mJ/cm ² A colored layer 3 (thickness: 150 μm) was prepared as an adhesive layer.

(production of optical semiconductor element sealing sheet)

The release liner (trade name "MRF 38") was peeled off from the colored layer 3 to expose the adhesive surface. The exposed surface of the colored layer 3 was bonded to an easy-to-bond treated surface of a base film (trade name "Diafoil T912E75 (UE 80-)", mitsubishi chemical corporation, which had been subjected to an easy-to-bond treatment on one side of a polyethylene terephthalate film, and a thickness of 75 μm), and a sealing layer formed of the colored layer 3 was formed on the base film.

Then, the resultant was bonded with a manual roller at room temperature (23 ℃) so as not to mix air bubbles, and left under light shielding for two days. Thus, a sheet for sealing an optical semiconductor element, which is formed of [ release liner/colored layer 3/base film ], was obtained.

Comparative example 4

(production of non-diffusion functional layer 4)

The photopolymerizable composition produced in production example 5 was applied to a release-treated surface of a release liner (trade name "MRA50", manufactured by Mitsubishi chemical corporation, a release treatment was applied to one side of a polyethylene terephthalate film, and the thickness was 50 μm) to form a resin composition layer, and then the release-treated surface of the release liner (trade name "MRF38", manufactured by Mitsubishi chemical corporation) was also bonded to the resin composition layer. Next, the irradiation intensity with black light was 5mW/cm ² Ultraviolet polymerization was carried out until the cumulative light amount was 3600mJ/cm ² A non-diffusion functional layer 4 (thickness: 150 μm) was prepared as an adhesive layer.

(production of optical semiconductor element sealing sheet)

The release liner (trade name "MRF 38") was peeled off from the non-diffusion functional layer 4 to expose the adhesive surface. The exposed surface of the non-diffusion functional layer 4 was bonded to an adhesion-facilitating surface of a base film (trade name "Diafoil T912E75 (UE 80-)", manufactured by mitsubishi chemical company, to which one surface of a polyethylene terephthalate film was subjected to an adhesion-facilitating treatment, and a thickness of 75 μm), and a sealing layer formed of the non-diffusion functional layer 4 was formed on the base film.

Then, the resultant was bonded with a manual roller at room temperature (23 ℃) so as not to mix air bubbles, and left under light shielding for two days. Thus, an optical semiconductor element sealing sheet formed of [ release liner/non-diffusion functional layer 4/base film ] was obtained.

Comparative example 5

(preparation of diffusion functional layer 5)

The photopolymerizable composition produced in production example 3 was applied to a release-treated surface of a release liner (trade name "MRA50", manufactured by Mitsubishi chemical corporation, a release treatment was applied to one side of a polyethylene terephthalate film, and the thickness was 50 μm) to form a resin composition layer, and then the release-treated surface of the release liner (trade name "MRF38", manufactured by Mitsubishi chemical corporation) was also bonded to the resin composition layer. Next, the irradiation intensity with black light was 5mW/cm ² Ultraviolet polymerization was carried out until the cumulative light amount was 3600mJ/cm ² A diffusion functional layer 5 (thickness: 150 μm) was prepared as an adhesive layer.

(production of optical semiconductor element sealing sheet)

The release liner (trade name "MRF 38") was peeled off from the diffusion functional layer 5 to expose the adhesive surface. The exposed surface of the diffusion functional layer 5 was bonded to an easy-to-bond treated surface of a base film (trade name "Diafoil T912E75 (UE 80-)", mitsubishi chemical corporation, obtained by subjecting one surface of a polyethylene terephthalate film to an easy-to-bond treatment, and having a thickness of 75 μm), and a sealing layer formed of the diffusion functional layer 5 was formed on the base film.

Then, the resultant was bonded with a manual roller at room temperature (23 ℃) so as not to mix air bubbles, and left under light shielding for two days. Thus, an optical semiconductor element sealing sheet formed of [ release liner/diffusion functional layer 5/base film ] was obtained.

Comparative example 6

(production of optical semiconductor element sealing sheet)

An optical semiconductor element sealing sheet was obtained in the same manner as in example 1, except that the layers shown in table 2 were formed as the first sealing layer, the second sealing layer, and the third sealing layer.

< evaluation >

The following evaluations were performed on the optical semiconductor element sealing sheets obtained in examples and comparative examples. The results are shown in the table.

(1) Total light transmittance (layers)

The release liners on one side were peeled off from the adhesive layers (in the form of being sandwiched by 2 release liners) used in examples and comparative examples, and the exposed surfaces of the adhesive layers were bonded to glass plates (glass slide, model "S-9112", manufactured by Song Nitro Corp Co., ltd.). Then, the other side of the release liner was peeled off to prepare a measurement sample having a layer structure of [ glass plate/adhesive layer ]. For the above measurement samples, total light transmittance was measured by a haze meter (device name "HM-150", manufactured by color technology research, inc.). Measurement light is incident from the adhesive layer side to perform measurement.

(2) Haze value (layers)

For the measurement sample prepared for measuring the total light transmittance of the above (1), the total light transmittance and the diffuse transmittance were measured by a haze meter (device name "HM-150", manufactured by color technology research Co., ltd.). Then, the haze value of the measurement sample was obtained by the mathematical expression of "diffuse transmittance/total transmittance×100", and was used as the initial haze value.

(3) Total light transmittance (optical semiconductor element sealing sheet)

The release liners were peeled off from the optical semiconductor element sealing sheets of examples and comparative examples, and the exposed adhesive layer was bonded to a glass plate (glass slide, model "S-9112", manufactured by Song Nitro Co., ltd.) to prepare measurement samples. For the above measurement samples, total light transmittance was measured by a haze meter (device name "HM-150", manufactured by color technology research, inc.). Measurement light is incident from the substrate film side to perform measurement. In example 8, a sheet obtained by curing the adhesive layer by irradiation of ultraviolet rays from the substrate film side before measurement under the following conditions was used as a measurement sample.

< conditions for ultraviolet irradiation >

Ultraviolet irradiation device: trade name "UM810", manufactured by Nidong Seiko Co., ltd

Light source: high-pressure mercury lamp

Irradiation intensity: 50mW/cm ² ( Measurement device: trade name "Ultrascalometer UT-101", manufactured by USHIO Motor Co., ltd )

Irradiation time: 6 seconds

Cumulative light amount: 300mJ/cm ²

(4) Haze value (optical semiconductor element sealing sheet)

For the measurement sample prepared for measuring the total light transmittance, the total light transmittance and the diffuse transmittance were measured by a haze meter (device name "HM-150", manufactured by color technology research, inc.). Then, the haze value of the measurement sample was obtained by the mathematical expression of "diffuse transmittance/total transmittance×100", and used as the haze value. Measurement light is incident from the substrate film side (first surface side) to perform measurement.

(5)L ^* (1) (to be adhered to an adherend having no irregularities)

The surface of the semiconductor element sealing sheet obtained in examples and comparative examples after peeling off the release liner was bonded to the surface of an inner wrap of aluminum foil (width 30 cm. Times.length 50 m. Times.thickness 12 μm) made by Mitsubishi aluminum Co., ltd.) with a manual roller without air bubbles. After bonding, the laminate was left under shade at 25℃for 30 minutes. Then, the object attached in a size of more than 5.0cm×5.0cm was cut out. Then, the measurement sample was left standing on a flat surface with the base film of the optical semiconductor element sealing sheet facing outward. Then, L was carried out from the side of the substrate film surface by using a spectrocolorimeter (trade name "CM-26dG", manufactured by Konica Minolta, inc.) ^* (SCI) (1) and L ^* (SCE) (1) measurement. The measurement is performed by using the measurement area of the colorimeterThe center of the sample was set and measured under the following conditions. Before measurement by the above-mentioned spectrocolorimeter, zero point correction, white correction, and GROSS correction were performed according to the manufacturer's manual. When the measurement is performed using only aluminum foil (inner wrap surface), L ^* (SCI) 95.88, L ^* (SCE) 88.32. In example 8, a sheet obtained by curing the adhesive layer by irradiation of ultraviolet light from the substrate film side under the conditions described in the total light transmittance (3) before measurement was used as a measurement sample.

The measuring method comprises the following steps: color and luster

Geometry: di:8 °, de:8 degree

Regular reflected light treatment: SCI+SCE

Observation light source: d65 (D65)

Observation conditions: 10 degree view

Diameter measurement: MAV (8 mm)

UV conditions: 100% full

Automatic average measurement: 3 times

Zero point correction: effective and effective

(6)L ^* (2) (to be adhered to an adherend having irregularities)

< preparation of adherend having irregularities >

(preparation of silicon wafer)

A back surface polishing tape (trade name "ELP UB-3083D", manufactured by Nito Denko Co., ltd.) was bonded to one surface of an 8-inch-sized silicon mirror wafer, and the back surface side of the wafer was subjected to back polishing. The back surface polishing was performed using a polishing apparatus (trade name "DFG-8560", manufactured by Disco, inc.) so that the thickness of the wafer after the back surface polishing was 40. Mu.m.

(production of chip-mounting film)

An adhesive composition solution having a solid content of 20% was prepared by dissolving, in methyl ethyl ketone, 79 parts by mass of an epoxy resin (trade name "HP-400", manufactured by DIC Co., ltd.), 93 parts by mass of a phenol resin (trade name "H-4", manufactured by Ming and Chemie Co., ltd.), 189 parts by mass of spherical silica (trade name "SO-25R", manufactured by Admatechs Co., ltd.), and 0.6 part by mass of a curing catalyst (trade name "2PHZ", manufactured by Kiku Chemie Co., ltd.) in 100 parts by mass of an acrylic resin (trade name "SG-70L", manufactured by Nagase ChemteX Corporation). Then, the adhesive composition solution was applied to a release liner (trade name "MRF30", manufactured by Mitsubishi chemical corporation), and the solvent was volatilized and cured by heating at 150℃for 2 minutes, thereby producing a chip attach film having a thickness of 10. Mu.m.

(bonding of die-attached film to 40 μm thick wafer)

The die attach film was attached to the entire surface of one side of a 40 μm thick wafer using a hand roll at 40 ℃.

(bonding of die-attached film and aluminum foil)

The release liner was peeled off from the die attach film, and the whole surface of the outer roll of aluminum foil was attached to the surface by using a manual roller at 40 ℃. Then, the die attach film was cured by heating in an oven at 150℃for 1 hour. And (5) returning to room temperature, and cutting the aluminum foil and the chip mounting film along the shape of the wafer by using a cutter.

(cutting)

The aluminum foil surface of [ wafer/die attach film/aluminum foil ] was bonded to a dicing sheet (trade name "ELP DU-2187G", manufactured by niton corporation). Next, a dicing ring for an 8-inch wafer was attached to the wafer-non-mounted area of the dicing sheet by a manual roller. Then, the wafer was cut into a size of 20 mm. Times.20 mm using a dicing apparatus (trade name "DFD-6450", manufactured by Disco, inc.), to obtain silicon chips (20 mm. Times.20 mm) having a tape [ aluminum foil/die attach film ]. The silicon chip was taken out by irradiating ultraviolet rays from the base surface of the dicing sheet under the following conditions.

< conditions for ultraviolet irradiation >

Light source: high-pressure mercury lamp

Irradiation time: 6 seconds

Cumulative light amount: 300mJ/cm ²

< bonding of sheet for sealing optical semiconductor element >

An 8 inch unground Si mirror wafer was prepared. The silicon chips were placed on the surface of the sealing sheet for optical semiconductor element obtained in examples and comparative examples with the aluminum foil facing upward, and the surfaces after the release liners were peeled off and bonded using a bonding device under the following conditions. The silicon chip is bonded to the optical semiconductor element sealing sheet.

The device comprises: trade name "DR-3000III", manufactured by Nidong Seiko Co., ltd

Table heating temperature: 80 DEG C

Table type: 8 inch table (FOR 700)

Sticking pressure: 0.5MPa (pressure 100%)

Sticking speed: 2mm/sec

An 8-inch mirror wafer on which a laminate of silicon chips with an aluminum foil/die attach film is mounted is left to stand on a flat surface with the base film of the optical semiconductor element sealing sheet facing outward. Silicon chips (length 20 mm. Times. Width 20 mm. Times. Thickness 62 μm) with [ aluminum foil/die attach film ] were mounted on the above mirror wafer.

L was carried out by disposing the entire surface of a measuring section of a spectrocolorimeter (trade name "CM-26dG", manufactured by Konica Minolta, inc.) on the surface of a base film of a sheet for sealing an optical semiconductor element, which is adhered to a portion where an aluminum foil exists ^* (SCI) (2) and L ^* (SCE) (2) measurement. L (L) ^* (SCI) (2) and L ^* The measurement conditions of (SCE) (2) were set to be equal to L ^* (SCI) (1) and L ^* (SCE) (1) is the same. Before measurement by the above-described spectrocolorimeter, zero point correction, white correction, and GROSS correction were performed according to the manufacturer's manual. In example 8, a sheet obtained by curing the adhesive layer by irradiation of ultraviolet light from the substrate film side under the conditions described in the total light transmittance (3) before measurement was used as a measurement sample.

(7) Light diffusion effect confirmation test

The release liners of the optical semiconductor element sealing sheets obtained in examples and comparative examples were peeled off and bonded to a glass plate (glass slide, model "S-9112", manufactured by Song Nitro Corp Co., ltd., 76 mm. Times.52 mm. Times.1.0 to 1.2 mm) using a manual roller so as not to mix air bubbles. After bonding, the laminate was left under light shielding at 25℃for 30 minutes. The bonded optical semiconductor element sealing sheet was cut to the same size as the glass plate, and a measurement sample was produced. An LED lamp (trade name "LK-3PG", EK JAPAN co., ltd.) was set at the upper part of the screen in a height of 2.4 cm. The glass plate side of the obtained measurement sample was brought into close contact with an LED lamp. A battery case (trade name "AP-180", manufactured by EK JAPANCO., LTD.) was attached to the LED lamp to turn on the LED lamp, and the diameter of the circular image reflected on the screen was measured. When the measurement was performed only on the glass plate without the optical semiconductor element sealing sheet, the diameter of the light reflected on the screen was 4.0cm. When the optical path is 5.0cm or more as measured through the optical semiconductor element sealing sheet, it is judged that the light diffusion effect is present.

(8) Determination of

Based on the results of the above evaluations (5) to (7), L is ^* (SCI)、L ^* (SCE) and light diffusion effect were performed based on the following criteria. And, as a comprehensive judgment, L ^* (SCI)、L ^* (SCE) and the light diffusion effect were all marked with "o", and even 1 x.

L ^* (SCI): will L ^* (SCI) (1) and L ^* The cases where (SCI) (2) were 60 or less were marked as "O" and the cases where (SCI) (2) exceeded 60 were marked as "X".

L ^* (SCE): will L ^* (SCE) (1) and L ^* The cases where (SCE) (2) were 60 or less were marked as o and the cases where (SCE) (2) were more than 60 were marked as x.

Light diffusion effect: the case of 5.0cm or more was marked as "O" and the case of less than 5.0cm was marked as "X".

TABLE 1

TABLE 2

As shown in Table 1, the optical semiconductor element sealing sheet (example) of the present invention has L ^* (SCI) and L ^* (SCE) was evaluated as excellent in appearance in the state of sealing the optical semiconductor element because it was 60 or less for both the adherend without irregularities and the adherend with irregularities. Further, since the light diffusion effect was 5.0cm or more, it was evaluated that luminance unevenness was less likely to occur.

On the other hand, as shown in Table 2, when the colored layer is positioned in the first sealing layer in contact with the optical semiconductor element, L of the adherend having irregularities is present ^* (SCI) and L ^* Since (SCE) exceeded 60, it was judged that the appearance was poor (comparative examples 1 and 2). When the sealing portion is formed of a single layer of the coloring layer, L ^* (SCI) and L ^* (SCE), since the light diffusion effect was less than 5.0cm, it was judged that the effect of suppressing the luminance unevenness was insufficient (comparative example 3). When the sealing portion was formed of a single layer of the non-diffusion functional layer, it was found that the effect of suppressing the uneven brightness was insufficient because the light diffusion effect was less than 5.0cm because the uneven adherend and the uneven adherend were both more than 60 (comparative example 4). When the sealing part is formed by a single diffusion functional layer, L ^* (SCI) and L ^* Since (SCE) exceeded 60, it was judged that the appearance was poor (comparative example 5). When the diffusion functional layer was not provided, the light diffusion effect was less than 5.0cm, and therefore, the effect of suppressing the luminance unevenness was judged to be insufficient (comparative example 6).

Claims

1. A sealing sheet for sealing at least 1 optical semiconductor element disposed on a substrate,

the sheet is provided with: a first sealing layer in contact with the optical semiconductor element; a second sealing layer laminated on the first sealing layer; and a third sealing layer laminated on the second sealing layer and having adhesiveness and/or adhesiveness,

the second sealing layer and/or the third sealing layer comprises a colorant,

more than 1 selected from the group consisting of the first sealing layer, the second sealing layer, and the third sealing layer are diffusion functional layers.

2. The sheet for sealing an optical semiconductor element according to claim 1, wherein the first sealing layer is a diffusion functional layer.

3. The sheet for sealing an optical semiconductor element according to claim 1 or 2, wherein the third sealing layer is a diffusion functional layer.

4. The sheet for sealing an optical semiconductor element according to claim 1 or 2, wherein the diffusion functional layer contains light-diffusing fine particles.

5. The sheet for sealing an optical semiconductor element according to claim 4, wherein the light-diffusing fine particles are composed of a silicone resin and/or a metal oxide.

6. The optical semiconductor element sealing sheet according to claim 1 or 2, wherein a ratio [ L (SCI) (2)/L (SCI) (1) ] of L (SCI) (2) to L (SCI) (1) and/or a ratio [ L (SCE) (2)/L (SCE) (1) ] of L (SCE) (2) to L (SCE) (1) defined below is 1.2 or less,

l (SCI) (1): l x (SCI) measured from the third sealing layer side in a state in which the first sealing layer of the optical semiconductor element sealing sheet is bonded to the aluminum foil;

l (SCI) (2): l x (SCI) measured from the third sealing layer side in the following state: placing a convex sample having an aluminum foil on a surface thereof and having a length of 20mm×a width of 20mm×a thickness of 62 μm on a substrate having a larger size than the convex sample, and bonding a first sealing layer of an optical semiconductor element sealing sheet to the substrate and the convex sample so that the optical semiconductor element sealing sheet covers the convex sample;

L (SCE) (1): l x (SCE) measured from the third sealing layer side in a state where the first sealing layer of the optical semiconductor element sealing sheet is bonded to the aluminum foil;

l (SCE) (2): l (SCE) measured from the third sealing layer side in the following state: a convex sample having an aluminum foil on the surface thereof and having a length of 20mm by a width of 20mm by a thickness of 62 μm is placed on a substrate having a size larger than the convex sample, and a first sealing layer of the optical semiconductor element sealing sheet is bonded to the substrate and the convex sample so that the optical semiconductor element sealing sheet covers the convex sample.

7. The sheet for sealing an optical semiconductor element according to claim 1 or 2, wherein the first sealing layer is a non-radiation curable resin layer.

8. The sheet for sealing an optical semiconductor element according to claim 1 or 2, wherein the second sealing layer and/or the third sealing layer is a radiation-curable resin layer.

9. An optical semiconductor device, comprising: a substrate; an optical semiconductor element disposed on the substrate; and the optical semiconductor element sealing sheet according to any one of claims 1 to 8 for sealing the optical semiconductor element.

10. The optical semiconductor device according to claim 9, which is a self-luminous display device.

11. An image display device provided with the self-luminous display device according to claim 10.