Dry film, integrated encapsulation sheet, light-emitting electronic component, and method for manufacturing same

Abstract

The present invention provides a dry film capable of further suppressing loss of luminance, an integrated encapsulation sheet, a light-emitting electronic component using the dry film, and a method for manufacturing the same.　The present invention relates to a dry film (1) to be press-bonded to a surface on which are arranged a plurality of light-emitting elements (21, 22, 23) of an element-equipped substrate 2 having the plurality of light-emitting elements (21, 22, 23) disposed on a substrate (20). The dry film (1) includes at least a black curable resin layer (10) for blocking light between the plurality of light-emitting elements (21, 22, 23), a first transparent curable resin layer (11) having higher light transmittance than the black curable resin layer (10), and a second transparent curable resin layer (12) having higher light transmittance than the black curable resin layer (10). The first transparent curable resin layer (11), the black curable resin layer (10), and the second transparent curable resin layer (12) are layered in the above order.

Description

Dry film, integrated encapsulating sheet, light-emitting electronic component, and method for manufacturing the same Cross Reference

[0001] This application claims priority under the Paris Convention based on Japanese Patent Application No. 2024-117842 filed in Japan on July 23, 2024, the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to a dry film, an integrated encapsulating sheet, a light-emitting electronic component using the dry film, and a method for producing the same.

[0003] In recent years, displays using extremely small light-emitting diodes known as mini-LEDs or micro-LEDs have been attracting attention. There are two main methods known for using such extremely small light-emitting diodes in displays. One method involves arranging a large number of light-emitting diodes on a substrate to form a backlight for a liquid crystal display and locally controlling the brightness of the backlight. The other method involves using light-emitting diodes of each color (red, green, and blue) to emit light of each color and sending it to the eyes of the viewer of the display on a pixel-by-pixel basis.

[0004] Light-emitting diodes such as mini-LEDs or micro-LEDs are generally arranged on a substrate. When multiple light-emitting diodes (referred to as light-emitting elements) are arranged on a substrate, it is necessary to provide light shielding between adjacent light-emitting elements. A method using a dry film, for example, is known as a method for providing light shielding between multiple light-emitting elements using a resin with a light-shielding function (see Prior Art 1 and Patent Document 1). The dry film is a film obtained by applying a light-shielding resin composition to a protective film and drying it.

[0005] When a dry film is pressed onto a substrate over multiple light-emitting elements, a light-shielding resin layer forms not only in the gaps between the light-emitting elements but also on the upper surfaces (light-emitting surfaces) of the light-emitting elements. Under such circumstances, the resin layer may block light from reaching the viewer of the display. To prevent this, the above-mentioned prior art 1 employs a method in which the light-emitting surfaces of the light-emitting elements are etched using a plasma treatment or other etching method to remove the resin layer on the light-emitting surfaces, and then the removed surfaces are re-covered with a light-transmitting sealant.

[0006] However, the etching process in the above-mentioned prior art 1 requires a long time, which increases manufacturing costs. Furthermore, it is difficult to completely remove the light-shielding resin layer (hereinafter also referred to as "light-shielding layer") on the light-emitting surface of the light-emitting element, making it difficult to completely prevent the diffusion of light that should reach the viewer's side of the display. In addition, a step of laminating a highly transparent sealing film after the etching process is required, which increases the number of manufacturing processes.

[0007] To solve the problems of the above-mentioned Prior Art 1, the inventors of the present invention previously developed a novel dry film having a laminated structure of a black curable resin layer for light blocking and a transparent curable resin layer having a higher light transmittance than the black curable resin layer, in which the storage elastic modulus of the transparent curable resin layer is greater than that of the black curable resin layer (see Prior Art 2 and Patent Document 2). When such a novel dry film is pressed toward the substrate with the black curable resin layer in contact with the top surfaces of multiple light-emitting elements, the black curable resin layer, pressed by the transparent curable resin layer, easily moves between the multiple light-emitting elements due to its relatively small storage elastic modulus. After attaching the dry film to the substrate, curing the black curable resin layer and the transparent curable resin layer results in a light-emitting electronic component in which the black layer fills the spaces between the multiple light-emitting elements and a transparent layer is disposed on the top surfaces of the multiple light-emitting elements. This solves the problems of the above-mentioned Prior Art 1.

[0008] JP 2022-22562 A JP 2024-19873 A

[0009] However, there is still room for improvement in the above-mentioned prior art 2. That is, to further reduce the loss of brightness caused by the black curable resin layer remaining on the top surface of the light-emitting element when the dry film is thermocompression bonded to the element-mounted substrate. There is a demand in the market for dry films with less brightness loss.

[0010] Therefore, an object of the present invention is to provide a dry film capable of further suppressing loss of brightness, an integrated encapsulating sheet, a light-emitting electronic component using the dry film, etc., and a method for manufacturing the same.

[0011] (1) A dry film according to one embodiment for achieving the above object is a dry film that is pressure-bonded to a surface of a substrate having a plurality of light-emitting elements arranged on the substrate, the dry film including at least a black curable resin layer for shielding light between the plurality of light-emitting elements, a first transparent curable resin layer having a higher optical transparency than the black curable resin layer, and a second transparent curable resin layer having a higher optical transparency than the black curable resin layer, the first transparent curable resin layer, the black curable resin layer, and the second transparent curable resin layer being laminated in this order. (2) In a dry film according to another embodiment, the second transparent curable resin layer may preferably have a storage modulus greater than that of the black curable resin layer at 100°C. (3) In a dry film according to another embodiment, the second transparent curable resin layer may preferably have a storage modulus greater than that of the first transparent curable resin layer at 100°C. (4) In a dry film according to another embodiment, the storage modulus of the first transparent curable resin layer may be greater than the storage modulus of the black curable resin layer at 100° C. (5) In a dry film according to another embodiment, the storage modulus of the second transparent curable resin layer may be greater than 1.0×10 at 100° C. ７ (6) In the dry film according to another embodiment, preferably, the black curable resin layer has a storage modulus of 1.0×10 Pa or less at 100° C. ５(7) In the dry film according to another embodiment, preferably, the storage modulus of the first transparent curable resin layer at 100° C. may be 1.0×10 Pa or less. ５ (8) In the dry film according to another embodiment, preferably, the second transparent curable resin layer has a storage modulus of 1.0 × 10 Pa or less at 150°C. ３Pa or more. (9) In a dry film according to another embodiment, preferably, the total light transmittance of the black curable resin layer in a cured state may be 0 to 30%. (10) In a dry film according to another embodiment, preferably, the total light transmittance of the first transparent curable resin layer in a cured state may be 50% or more. (11) In a dry film according to another embodiment, preferably, the total light transmittance of the second transparent curable resin layer in a cured state may be 50% or more. (12) In a dry film according to another embodiment, preferably, the thickness of the second transparent curable resin layer may be greater than the thickness of the black curable resin layer and the thickness of the first transparent curable resin layer. (13) In a dry film according to another embodiment, preferably, the thickness of the first transparent curable resin layer may be greater than the thickness of the black curable resin layer. (14) In a dry film according to another embodiment, preferably, the second transparent curable resin layer may contain a high-molecular-weight epoxy resin. (15) In a dry film according to another embodiment, preferably, the weight-average molecular weight of the high-molecular-weight epoxy resin may be 10,000 to 100,000. (16) In a dry film according to another embodiment, preferably, the second transparent curable resin layer may contain a phenoxy resin as the high-molecular-weight epoxy resin. (17) In a dry film according to another embodiment, preferably, the amount of the high-molecular-weight epoxy resin mixed in the second transparent curable resin layer may be 30 to 80 parts by mass per 100 parts by mass of the total resin solids content. (18) In a dry film according to another embodiment, preferably, the black curable resin layer may contain an elastomer. (19) In a dry film according to another embodiment, preferably, the elastomer may be a modified elastomer.(20) An integrated encapsulating sheet according to one embodiment to achieve the above object comprises: the dry film according to any one of (1) to (19); and a protective sheet for encapsulating the light-emitting element on a surface of the second transparent curable resin layer opposite to the surface on which the black curable resin layer is laminated, wherein the first transparent curable resin layer, the black curable resin layer, the second transparent curable resin layer, and the protective sheet are laminated in this order. (21) In the integrated encapsulating sheet according to another embodiment, preferably, the protective sheet comprises at least a support film layer for supporting the second transparent curable resin layer and a hard coat layer for scratch prevention, and the first transparent curable resin layer, the black curable resin layer, the second transparent curable resin layer, the support film layer, and the hard coat layer may be laminated in at least this order. (22) A light-emitting electronic component according to one embodiment for achieving the above object comprises: a device-mounted substrate having a plurality of light-emitting elements arranged on a substrate; and a cured dry film pressure-bonded to the surface of the device-mounted substrate on which the plurality of light-emitting elements are arranged, wherein the cured dry film comprises at least: a black resin layer for shielding light between the plurality of light-emitting elements, a first transparent resin layer having a higher optical transparency than the black resin layer, and a second transparent resin layer having a higher optical transparency than the black resin layer, wherein the first transparent resin layer, the black resin layer, and the second transparent resin layer are laminated in this order from the side in contact with the device-mounted substrate. (23) In a light-emitting electronic component according to another embodiment, preferably, the thickness of the black resin layer may be 50% or less of the height of the plurality of light-emitting elements. (24) To achieve the above object, a method for manufacturing a light-emitting electronic component according to one embodiment includes at least the steps of: placing the dry film according to any one of (1) to (19) on a surface of an element-mounted substrate on which a plurality of light-emitting elements are arranged, with the first transparent curable resin layer in contact with the surface, and thermocompression bonding the dry film; and curing the black curable resin layer, the first transparent curable resin layer, and the second transparent curable resin layer by heating. (25) In a method for manufacturing a light-emitting electronic component according to another embodiment, preferably, the temperature during the thermocompression bonding is 80 to 120°C, and the curing may be performed by heating at 100 to 160°C.

[0012] According to the present invention, it is possible to provide a dry film capable of further suppressing loss of brightness, an integrated encapsulating sheet, a light-emitting electronic component using the dry film, and a method for manufacturing the same.

[0013] FIG. 1 shows a cross-sectional view of the dry film according to the first embodiment when cut in the thickness direction. FIG. 2 shows a cross-sectional view, as seen from FIG. 1, of the dry film of FIG. 1 when the first transparent curable resin layer is placed in contact with the top surface of the light-emitting element of the element-mounted substrate. FIG. 3 shows a cross-sectional view, as seen from FIG. 1, of the dry film pressed onto the element-mounted substrate until the first transparent curable resin layer, the black curable resin layer, and the second transparent curable resin layer of FIG. 1 are embedded between the light-emitting elements, proceeding from the stage of FIG. 2. FIG. 4 shows a cross-sectional view, as seen from FIG. 1, of the state after a curing treatment has been performed, proceeding further from the stage of FIG. 3. FIG. 5 shows a cross-sectional view, as seen from FIG. 1, of the integrated encapsulating sheet and light-emitting electronic component according to the second embodiment.

[0014] 1... dry film, 2... substrate with element, 3... cured dry film, 4... integrated encapsulating sheet, 5, 5a... light-emitting electronic component, 6... integrated encapsulating cured sheet, 10... black curable resin layer, 11... first transparent curable resin layer, 12... second transparent curable resin layer, 14... support film layer, 15... protective sheet, 16... hard coat layer, 17, 18... release sheet, 20... substrate, 21, 22, 23... light-emitting element, 30... black resin layer, 31... first transparent resin layer, 32... second transparent resin layer.

[0015] Next, embodiments of the present invention will be described with reference to the drawings. Note that the embodiments described below do not limit the claimed invention, and not all of the elements and combinations thereof described in the embodiments are necessarily essential to the solution of the present invention. In this application, "main component" means a component that accounts for 50% by mass or more of the total solid content of the entire composition. In this application, "total resin solid content" means the total solid mass of the resin and elastomer, and if a curing agent is blended in addition to the elastomer, it also includes the solid mass of the curing agent. A numerical range expressed as "to" means a numerical range with the numbers before and after "to" as the lower and upper limits.

[0016] (First embodiment) Fig. 1 shows a cross-sectional view of a dry film according to the first embodiment when cut in the thickness direction. Fig. 2 shows a cross-sectional view, as seen from Fig. 1, of the dry film of Fig. 1 when the first transparent curable resin layer is placed in contact with the top surface of the light-emitting element of the element-mounted substrate. Fig. 3 shows a cross-sectional view, as seen from Fig. 1, of the dry film pressed onto the element-mounted substrate from the stage shown in Fig. 2 until the first transparent curable resin layer, the black curable resin layer, and the second transparent curable resin layer of Fig. 1 are embedded between the light-emitting elements. Fig. 4 shows a cross-sectional view, as seen from Fig. 1, of the dry film after undergoing a curing treatment from the stage shown in Fig. 3.

[0017] 1. Dry Film The dry film 1 according to this embodiment is a dry film 1 that is pressure-bonded to the surface of an element-mounted substrate 2 on which a plurality of light-emitting elements 21, 22, 23 are arranged, the surface having the plurality of light-emitting elements 21, 22, 23 arranged on a substrate 20, and includes at least a black curable resin layer 10 for blocking light between the plurality of light-emitting elements 21, 22, 23, and a first transparent curable resin layer 11 and a second transparent curable resin layer 12 that have higher light transmittance than the black curable resin layer 10. The dry film 1 is formed by laminating the first transparent curable resin layer 11, the black curable resin layer 10, and the second transparent curable resin layer 12 in this order.

[0018] In the present application, "light transmittance" refers to light transmittance measured by various known methods, and may be, for example, total light transmittance measured using a haze meter in accordance with JIS K 7361-1. In the present application, the total light transmittance of the black curable resin layer 10, the first transparent curable resin layer 11, and the second transparent curable resin layer 12 in their cured states, as described below, is a value obtained as follows. For example, in the case of the total light transmittance of the black curable resin layer 10 in its cured state, first, the total light transmittance of the release sheet alone, as described below, is measured using a haze meter (e.g., NDH5000 manufactured by Nippon Denshoku Industries Co., Ltd.) in accordance with JIS K 7361-1. Next, a laminate sheet is prepared in which the cured black curable resin layer 10 (i.e., the black resin layer 30) is laminated on a release sheet, and the total light transmittance of the laminate sheet is measured in the same manner. The total light transmittance of the release sheet alone is set to 100%, and a value obtained by excluding the influence of the release sheet from the total light transmittance of the obtained laminated sheet is calculated to be the total light transmittance in the cured state of the black curable resin layer 10. The total light transmittances of the first transparent curable resin layer 11 and the second transparent curable resin layer 12 in the cured state are obtained in the same manner by changing the black curable resin layer 10 to the first transparent curable resin layer 11 and the second transparent curable resin layer 12, respectively.

[0019] Furthermore, for ease of handling, the dry film 1 may have release sheets 17, 18 on the surface of either or both of the first transparent curable resin layer 11 and the second transparent curable resin layer 12. In this embodiment, the release sheets 17, 18 are provided on the surfaces of both the first transparent curable resin layer 11 and the second transparent curable resin layer 12.

[0020] Each layer constituting the dry film 1 will be described in detail below.

[0021] (1) Black Curable Resin Layer The black curable resin layer 10 is a layer that shields light between light-emitting elements and improves the contrast of the display. Furthermore, during the thermocompression bonding process, the black curable resin layer 10 sufficiently fills the spaces between the multiple light-emitting elements 21, 22, and 23 arranged on the element-mounted substrate 2, preventing poor appearance due to expansion of unfilled voids during the thermal curing process and damage to the light-emitting elements due to external factors in subsequent processes. In this embodiment, the black curable resin layer 10 is formed between the first transparent curable resin layer 11 and the second transparent curable resin layer 12. The black curable resin layer 10 is cured through a curing process to become the black resin layer 30 described below. In other words, the black curable resin layer 10 is an uncured layer.

[0022] [Storage Modulus] The storage modulus of the black curable resin layer 10 at 100°C is preferably smaller than that of the second transparent curable resin layer 12, and more preferably smaller than that of the first transparent curable resin layer 11. The black curable resin layer 10 may also be referred to as a "low-elasticity black curable resin layer." In the present application, "low elasticity" refers to a state in which the storage modulus of the black curable resin layer 10 at 100°C is lower than that of the layer with the highest storage modulus (in the present application, the second transparent curable resin layer 12). The same applies to the first transparent curable resin layer 11 described below. Since the storage modulus of the black curable resin layer 10 is smaller than that of the second transparent curable resin layer 12 at 100°C, the black curable resin layer 10 can be pressed by the second transparent curable resin layer 12 during thermocompression bonding, thereby appropriately filling the spaces between the light-emitting elements 21, 22, and 23. Furthermore, because the storage modulus of the black curing resin layer 10 is smaller than that of the first transparent curing resin layer 11 at 100°C, the black curing resin layer 10 is more likely to be subjected to stress on the top surfaces of the light-emitting elements 21, 22, and 23 due to support from the first transparent curing resin layer 11 during thermocompression bonding, and is more likely to be filled between the light-emitting elements 21, 22, and 23. This makes it less likely that the black curing resin layer 10 will remain on the top surfaces of the light-emitting elements 21, 22, and 23, making it possible to suppress brightness loss when the light-emitting electronic component 5 is turned on.

[0023] The storage modulus of the black curable resin layer 10 at 100° C. is preferably 1.0×10 ５ Pa or less, and more preferably 1.0 × 10 １ ~1.0 x 10５ Pa, and even more preferably 1.0×10 ２ ~5.0 x 10 ４ Pa. When the storage modulus of the black curable resin layer 10 at 100°C is equal to or less than the preferred upper limit, the black curable resin layer 10 exhibits sufficient fluidity when pressure-bonded to the plurality of light-emitting elements 21, 22, and 23, and can sufficiently fill the spaces between the plurality of light-emitting elements 21, 22, and 23. This makes it less likely that the black curable resin layer 10 will remain on the top surfaces of the light-emitting elements 21, 22, and 23, thereby suppressing brightness loss when the light-emitting electronic component 5 is turned on. When the storage modulus of the black curable resin layer 10 at 100°C is equal to or greater than the preferred lower limit, pressure unevenness during thermocompression bonding of the black curable resin layer 10 and the transparent curable resin layer 11 can be prevented, and a uniform appearance can be maintained. Furthermore, resin leakage outside the specified range can be prevented, ensuring a film thickness after pressure bonding.

[0024] The storage modulus of the black curable resin layer 10 at 150° C. is preferably 5.0×10 ５ Pa or less, and more preferably 1.0 × 10 １ ~5.0 x 10 ５ Pa, and even more preferably 1.0×10 １ ~1.0 x 10 ４ When the storage modulus of the black curable resin layer 10 at 150°C is equal to or less than the preferred upper limit, cracks due to cure shrinkage are less likely to occur during thermal curing. When the storage modulus of the black curable resin layer 10 at 150°C is equal to or greater than the preferred lower limit, flow during thermal curing can be suppressed, and poor appearance after curing, such as repellency, can be suppressed.

[0025] [Total Light Transmittance] The total light transmittance of the black curable resin layer 10 in a cured state is lower than the total light transmittance of the first transparent curable resin layer 11 and the second transparent curable resin layer 12 in a cured state. Specifically, the black curable resin layer 10 is prepared so that its total light transmittance in a cured state is preferably 0 to 30%, more preferably 0 to 20%, and even more preferably 0 to 10%. When the total light transmittance is equal to or less than an upper limit value such as 30%, 20%, or 10%, the black curable resin layer 10 can achieve light blocking between the light-emitting elements 21, 22, and 23 after curing. The total light transmittance in this specification can be measured using a haze meter in accordance with JIS K 7361-1. The total light transmittance in a cured state can be changed mainly by the presence or absence of carbon black or the amount of carbon black added. The total light transmittance in the cured state can also be changed by changing the thickness of the black curable resin layer 10 and the type of resin composition.

[0026] [Curable Resin Composition] The black curable resin layer 10 contains a curable resin composition. An example of the curable resin composition is a curable resin composition containing at least one resin selected from epoxy resin, acrylic resin, polyester resin, polyurethane resin, and silicone resin, and a curing agent. Among the above curable resin compositions, an epoxy resin composition having excellent heat resistance and reliability is preferred. In this specification, an epoxy resin composition refers to a composition containing an epoxy resin as a main component, or a composition containing an epoxy resin and a curing agent as main components.

[0027] When the black curable resin layer 10 is composed of an epoxy resin composition, it may contain a curing agent for epoxy resins other than the modified elastomer having a functional group reactive with an epoxy group. Examples of the other curing agent include known curing agents such as phenol-based curing agents, acid anhydride-based curing agents, and amine-based curing agents. Two or more of the other curing agents may be used in combination.

[0028] (Epoxy Resin) In the present application, an epoxy resin is a compound having an epoxy group in the molecule. The epoxy resin used in the present invention is preferably one having two or more epoxy groups in one molecule. This is because a crosslinked structure is formed by reaction with a modified resin having a functional group reactive with the epoxy group, and high heat resistance can be achieved in the cured product. Furthermore, when an epoxy resin having two or more epoxy groups is used, the degree of crosslinking with the curing agent having a functional group reactive with the epoxy group is sufficient, and sufficient heat resistance can be achieved in the cured product.

[0029] Examples of epoxy resins include bifunctional epoxy resins having two epoxy groups in the molecule, polyfunctional epoxy resins having three or more epoxy groups in the molecule, and high-molecular-weight epoxy resins having a weight-average molecular weight of 10,000 or more. These may also be hydrogenated epoxy resins. In this application, epoxy resins having a weight-average molecular weight of 10,000 or more are not classified as bifunctional epoxy resins or polyfunctional epoxy resins, but as high-molecular-weight epoxy resins, regardless of the number of epoxy groups in the molecule. The weight-average molecular weight of an epoxy resin is the molecular weight in terms of polystyrene measured by gel permeation chromatography.

[0030] Examples of epoxy resins include bisphenol-based epoxy resins such as bisphenol A type epoxy resins, bisphenol F type epoxy resins, or phenoxy resins obtained by polymerizing these resins, and hydrogenated versions of these resins; novolac type epoxy resins such as phenol novolac epoxy resins, o-cresol novolac epoxy resins, bisphenol A novolac epoxy resins, xylene structure-containing novolac epoxy resins, and naphthol novolac type epoxy resins; glycidyl ester-based epoxy resins such as phthalic acid diglycidyl ester, isophthalic acid diglycidyl ester, terephthalic acid diglycidyl ester, p-hydroxybenzoic acid glycidyl ester, tetrahydrophthalic acid diglycidyl ester, succinic acid diglycidyl ester, adipic acid diglycidyl ester, sebacic acid diglycidyl ester, and trimellitic acid triglycidyl ester; ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycidyl ether-based epoxy resins such as glycidyl ether, trimethylolpropane triglycidyl ether, pentaerythritol tetraglycidyl ether, tetraphenylglycidyl ether ethane, triphenylglycidyl ether ethane, polyglycidyl ether of sorbitol, and polyglycidyl ether of polyglycerol; glycidylamine-based epoxy resins such as triglycidyl isocyanurate and tetraglycidyldiaminodiphenylmethane; linear aliphatic epoxy resins such as epoxidized polybutadiene and epoxidized soybean oil; and special skeleton epoxy resins such as brominated bisphenol A-type epoxy resins, phosphorus-containing epoxy resins, fluorine-containing epoxy resins, dicyclopentadiene skeleton-containing epoxy resins, naphthalene skeleton-containing epoxy resins, anthracene-type epoxy resins, tertiary butylcatechol-type epoxy resins, triphenylmethane-type epoxy resins, tetraphenylethane-type epoxy resins, biphenyl-type epoxy resins, and bisphenol S-type epoxy resins, but are not limited to these.

[0031] Examples of high molecular weight epoxy resins that can be used include phenoxy resin, epoxy-modified polybutadiene, copolymers of glycidyl methacrylate and methyl methacrylate, modified polymers obtained by epoxy-modifying other resins, etc. These epoxy resins may be used alone or in combination of two or more.

[0032] Among the above epoxy resins, polyfunctional epoxy resins are preferred as the epoxy resin used in the black curable resin layer 10 from the viewpoint of increasing the crosslink density after curing. Among polyfunctional epoxy resins, novolac-type epoxy resins are particularly more preferred for the following reasons. Novolac-type epoxy resins are epoxy resins that can be appropriately introduced with a flexible skeleton, allowing for adjustment of flexibility and softening point. This makes the cured product less susceptible to brittle fracture, improves the performance stability of the cured product of the epoxy resin composition over long-term use, and increases the crosslink density. In addition, the heat resistance of the cured product is also improved.

[0033] Specific examples of novolac-type epoxy resins include "YX7700" manufactured by Mitsubishi Chemical Corporation, "NC7000L", "XD1000", and "EOCN-1020" manufactured by Nippon Kayaku Co., Ltd., "ESN485" manufactured by Nippon Steel Chemical & Material Co., Ltd., and "N-660", "N-690", "N-695", and "HP-7200H" manufactured by DIC Corporation.

[0034] The blending amount of the polyfunctional epoxy resin in the black curing resin layer 10 is preferably 10 to 99 parts by mass, more preferably 40 to 95 parts by mass, and even more preferably 60 to 90 parts by mass, relative to 100 parts by mass of the total resin solids content of the black curing resin layer 10. When the blending amount is equal to or greater than the lower limit, the crosslinking density can be increased, thereby imparting chemical resistance and heat resistance. When the blending amount is equal to or less than the upper limit, the storage modulus during thermocompression bonding can be adjusted, thereby ensuring the fluidity of the black curing resin layer 10.

[0035] The black curable resin layer 10 preferably does not contain a high-molecular-weight epoxy resin. This makes it easier to ensure sufficient fluidity of the black curable resin layer 10 during thermocompression bonding. When the black curable resin layer 10 contains a high-molecular-weight epoxy resin, the blending amount of the high-molecular-weight epoxy resin is preferably less than 50 parts by mass, more preferably less than 30 parts by mass, and even more preferably less than 10 parts by mass, relative to 100 parts by mass of the total resin solid content of the black curable resin layer 10.

[0036] From the viewpoint of ensuring sufficient fluidity during thermocompression bonding, the black curable resin layer 10 preferably contains an epoxy resin having a softening point or melting point of 100° C. or less. From the viewpoint of handleability and heat resistance of the cured product, the black curable resin layer 10 more preferably contains an epoxy resin having a softening point or melting point of 40 to 95° C. By containing an epoxy resin having a softening point or melting point within the above range, it becomes easier to control the storage modulus of the black curable resin layer 10.

[0037] The total amount of epoxy resin in the black curing resin layer 10 is preferably 10 to 100 parts by mass, more preferably 20 to 99 parts by mass, and even more preferably 35 to 95 parts by mass, relative to 100 parts by mass of the total resin solids content of the black curing resin layer 10. Within this range, it is easy to control the storage modulus of the black curing resin layer 10, and appropriate fluidity during thermocompression bonding can be ensured. Furthermore, when the amount is equal to or greater than the above lower limit, the heat resistance of the black curing resin layer 10 after curing can be improved.

[0038] (Elastomer) The black curable resin layer 10 preferably contains an elastomer in addition to a resin such as an epoxy resin. By containing an elastomer, it becomes easier to control the storage modulus of the black curable resin layer 10, i.e., to control the fluidity.

[0039] As the elastomer, a thermosetting elastomer, commonly referred to as "rubber," is preferred because it provides excellent heat resistance. Examples of thermosetting elastomers include acrylonitrile butadiene rubber (NBR), which is a random copolymer of butadiene and acrylonitrile, acrylic rubber, styrene butadiene rubber, vinyl acetate resin, and silicone resin. Among these, NBR is preferred. NBR has good compatibility with epoxy resins, making it easy to control the fluidity of the black curable resin layer 10 at around 100°C, thereby improving adhesion between the black curable resin layer 10 and the first and second transparent curable resin layers 11 and 12.

[0040] The weight-average molecular weight of the elastomer is preferably 100,000 to 1,000,000, more preferably 120,000 to 500,000, and even more preferably 150,000 to 300,000. When the weight-average molecular weight of the elastomer is within the above range, it is easy to control the storage modulus of the black curable resin layer 10, and fluidity during thermocompression bonding can be ensured. When the weight-average molecular weight of the elastomer is equal to or less than the above upper limit, compatibility between the elastomer and the epoxy resin is improved, and fluidity during thermal curing of the black curable resin layer 10 can be more effectively controlled.

[0041] In particular, when the black curable resin layer 10 is composed of an epoxy resin composition, it preferably contains a modified elastomer having a functional group reactive with an epoxy group. The modified elastomer having a functional group reactive with an epoxy group also functions as a curing agent for the epoxy resin. Furthermore, because the modified elastomer can react and bond with the epoxy resin, the heat resistance and thermal shock resistance of the cured black curable resin layer 10 are improved. Furthermore, the difference in polarity between the functional group reactive with the epoxy resin and the resin skeleton has a favorable effect on dispersibility, and good dispersibility can be obtained when carbon black is contained in the black curable resin layer 10.

[0042] Examples of functional groups that can react with epoxy groups include acid groups such as carboxy groups, sulfo groups, nitro groups, and phosphate groups, as well as their acid anhydride groups, hydroxyl groups, and amino groups. Among these, acid groups and acid anhydride groups are preferred because they allow curing at low temperatures and ensure a long usable time. For the same reasons, carboxy groups and carboxylic acid anhydride groups are particularly preferred.

[0043] That is, when the black curable resin layer 10 is composed of an epoxy resin composition, it preferably contains an acid-modified elastomer having an acid group or an acid anhydride group, more preferably contains an acid-modified elastomer having a carboxy group, and even more preferably contains modified NBR having a carboxy group.

[0044] The modified NBR having a carboxy group is preferably a carboxylated acrylonitrile rubber into which acrylic acid, methacrylic acid, maleic anhydride, etc. have been introduced. Commercially available carboxylated acrylonitrile rubbers include "NX775" and "1072CGJ" manufactured by Zeon Corporation. Two or more modified elastomers having a functional group reactive with an epoxy group may be used in combination.

[0045] The amount of elastomer in the black curable resin layer 10 is preferably 0.01 to 90 parts by mass, more preferably 1 to 80 parts by mass, and even more preferably 5 to 65 parts by mass, relative to 100 parts by mass of the total resin solids content of the black curable resin layer 10. Within this range, the storage modulus of the black curable resin layer 10 can be easily controlled, and appropriate fluidity of the black curable resin layer 10 during thermocompression bonding can be ensured. Furthermore, when the amount is equal to or greater than the lower limit, the dispersibility of carbon black in the epoxy resin composition is improved. Furthermore, the film-forming properties of the epoxy resin composition are improved, and the film thickness distribution can be narrowed when the epoxy resin composition is applied to form a film.

[0046] (Curing Agent) When the black curable resin layer 10 is composed of an epoxy resin composition, it may contain a curing agent for epoxy resins other than the modified elastomer having a functional group reactive with an epoxy group. Examples of the other curing agent include known curing agents such as phenol-based curing agents, acid anhydride-based curing agents, and amine-based curing agents. Two or more of the other curing agents may be used in combination.

[0047] (Curing Catalyst) When the black curable resin layer 10 is composed of an epoxy resin composition, it may contain a curing catalyst that promotes the curing reaction of the epoxy resin. Examples of curing catalysts include imidazole-based, tertiary amine-based, and phosphorus compound-based catalysts. Among these, imidazole-based catalysts are preferred because they are compatible with epoxy resins and less likely to cause yellowing. Among imidazole-based curing catalysts, those containing a cyanoethyl group are particularly preferred because they are easily soluble in epoxy resins. The amount of curing catalyst is preferably 0.01 to 5 parts by mass, more preferably 0.05 to 4 parts by mass, and even more preferably 0.3 to 4 parts by mass, per 100 parts by mass of the total resin solids content of the black curable resin layer 10. Within the above ranges, the curing of the black curable resin layer 10 can be sufficiently promoted, ensuring the usable life of the dry film 1. Two or more curing catalysts may be used in combination.

[0048] (Black Pigment Such as Carbon Black) The black curable resin layer 10 is colored black, and for coloring purposes, it may preferably contain carbon black, titanium oxide, iron oxide, etc., more preferably carbon black. By containing carbon black, it is possible to achieve light-blocking properties between the multiple light-emitting elements 21, 22, and 23 of the element-mounted substrate 2.

[0049] The particle size of the carbon black is preferably 10 to 500 nm, more preferably 10 to 300 nm, and even more preferably 10 to 100 nm. The particle size refers to the average particle size, and in this specification, the average particle size of carbon black refers to the average particle size measured by a dynamic light scattering method. An example of a measuring device using the dynamic light scattering method is the NanotracWave II UT151 manufactured by MicrotracBell.

[0050] As the carbon black, one or more types of known carbon black such as gas black, channel black, furnace black, thermal black, and lamp black can be used. Resin-coated carbon black may also be used. Furthermore, carbon nanofibers and carbon nanotubes may also be used.

[0051] Among the above options, gas black is preferred because it has a large amount of surface functional groups, is highly dispersible, and exhibits sufficient light-blocking properties even when added in small amounts. Furthermore, when the black curable resin layer 10 contains a modified elastomer having functional groups reactive with epoxy resins, the dispersibility is further improved due to the interaction between the surface functional groups of the gas black and the functional groups of the modified elastomer having functional groups reactive with epoxy resins, thereby ensuring good light-blocking properties and coating liquid stability.

[0052] The amount of carbon black is preferably 0.1 to 15 parts by mass, and more preferably 1.0 to 10 parts by mass, per 100 parts by mass of the total resin solids content of the black curable resin layer 10. When the amount of carbon black is equal to or greater than the above-mentioned lower limit, sufficient light-blocking properties are obtained. When the amount of carbon black is equal to or less than the above-mentioned upper limit, the thixotropy of the black curable resin layer 10 is suppressed, the fluidity during thermocompression bonding is improved, and the spaces between the multiple light-emitting elements 21, 22, and 23 of the element-mounted substrate 2 can be sufficiently filled.

[0053] (Other Components) The black curable resin layer 10 may contain an inorganic filler in order to improve flame retardancy and heat resistance and to adjust the refractive index.

[0054] The black curable resin layer 10 may further contain, as needed, resins other than the epoxy resin and elastomer, thickeners, antifoaming agents and / or leveling agents, adhesion promoters such as coupling agents, and flame retardants.

[0055] [L*a*b* Values] The L*a*b* values ​​of the black curable resin layer 10 in a cured state, measured in accordance with JIS Z 8781-4:2013 using a D65 light source, a 2° field of view, a reflection method, and an SCE method, are preferably L*: 3 to 40, a*: -10 to 10, and b*: -20 to 20, and more preferably L*: 3 to 30, a*: -5 to 5, and b*: -15 to 15. The L*a*b* values ​​are measured using a standard white calibration plate. Because the light transmittance of the black curable resin layer 10 is low, the influence of the standard white calibration plate is minimal. By having the L*a*b* values ​​in the cured state within the preferred range, the black curable resin layer 10, after curing, can shield light between the light-emitting elements 21, 22, and 23, thereby further improving the contrast of the display. The same indices are used for the uncured black curable resin layer 10.

[0056] [Film Thickness] The thickness of the black curable resin layer 10 is not particularly limited, but is preferably 0.05 to 100 μm, more preferably 0.5 to 70 μm, and even more preferably 0.75 to 50 μm.

[0057] (2) First Transparent Curable Resin Layer The first transparent curable resin layer 11 is a layer having higher light transmittance than the black curable resin layer 10, and is disposed on the top surfaces of the light emitting elements 21, 22, and 23 during thermocompression bonding, filling the spaces between the light emitting elements 21, 22, and 23. In this embodiment, the first transparent curable resin layer 11 is formed on the surface of the black curable resin layer 10 opposite to the surface on which the second transparent curable resin layer 12 is formed. The first transparent curable resin layer 11 is cured through a curing process to become the first transparent resin layer 31 described below. In other words, the first transparent curable resin layer 11 is an uncured layer. The fluidity of the resin near the top surfaces of the light-emitting elements 21, 22, and 23 is limited by friction with the top surface, and therefore it is likely to remain after thermocompression bonding. However, by placing the first transparent curable resin layer 11 on the light-emitting elements 21, 22, and 23 instead of the black curable resin layer 10 and then thermocompressing the resin, it is possible to further reduce the amount of the black curable resin layer 10 remaining on the top surfaces of the light-emitting elements 21, 22, and 23, thereby increasing brightness.

[0058] [Storage Modulus] The storage modulus of the first transparent curable resin layer 11 at 100°C is preferably smaller than that of the second transparent curable resin layer 12, and more preferably larger than that of the black curable resin layer 10. The first transparent curable resin layer 11 may also be referred to as a "low-elasticity transparent curable resin layer." Because the storage modulus of the first transparent curable resin layer 11 is smaller than that of the second transparent curable resin layer 12 at 100°C, the first transparent curable resin layer 11 is pressed by the second transparent curable resin layer 12 during thermocompression bonding, allowing the first transparent curable resin layer 11 to appropriately fill the spaces between the light-emitting elements 21, 22, and 23. Furthermore, because the storage modulus of the first transparent curable resin layer 11 is larger than that of the black curable resin layer 10 at 100°C, the first transparent curable resin layer 11 supports the black curable resin layer 10 during thermocompression bonding, making it easier to transmit stress during compression bonding and making it easier to fill the spaces between the light-emitting elements 21, 22, and 23 with the black curable resin layer 10. This makes it more difficult for the black curable resin layer 10 to remain on the top surfaces of the light emitting elements 21, 22, and 23, and ultimately makes it possible to suppress brightness loss when the light emitting electronic component 5 is turned on.

[0059] The storage modulus of the first transparent curable resin layer 11 at 100° C. is preferably 1.0×10 ５ Pa or less, and more preferably 1.0 × 10 １ ~1.0 x 10 ５ Pa, and even more preferably 1.0×10 ２ ~5.0 x 10 ４ It is Pa.

[0060] When the storage modulus of the first transparent curable resin layer 11 at 100°C is equal to or less than the preferred upper limit, the first transparent curable resin layer 11 exhibits sufficient fluidity when pressure-bonded to the plurality of light-emitting elements 21, 22, 23, and can sufficiently fill the spaces between the plurality of light-emitting elements 21, 22, 23. When the storage modulus of the first transparent curable resin layer 11 at 100°C is equal to or greater than the preferred lower limit, stress during pressure-bonding can be easily transmitted to the black curable resin layer 10 on the top surfaces of the light-emitting elements 21, 22, 23. In addition, uneven pressure during thermocompression bonding of the black curable resin layer 10 can be prevented, and a uniform appearance of blackness can be maintained. In addition, resin outflow outside a predetermined range can be prevented, ensuring a film thickness after pressure-bonding.

[0061] The storage modulus of the first transparent curable resin layer 11 at 100°C is preferably 10 to 200 times the storage modulus of the black curable resin layer 10 at 100°C, and more preferably 10 to 100 times the storage modulus of the black curable resin layer 10 at 100°C. By being within this numerical range, the first transparent curable resin layer 11 is not hindered from filling between the light emitting elements 21, 22, and 23, and the black curable resin layer 10 can be supported during thermocompression bonding. This in turn improves the conformability of the entire dry film 1 to the element-mounted substrate 2, allowing fewer voids to be filled.

[0062] [Total Light Transmittance] The total light transmittance of the first transparent curable resin layer 11 in a cured state is higher than the total light transmittance of the black curable resin layer 10 in a cured state. The total light transmittance of the first transparent curable resin layer 11 in a cured state is not particularly limited, but is preferably adjusted to be 50% or higher. The total light transmittance is preferably adjusted to be 50 to 95%, more preferably adjusted to be 60 to 95%, even more preferably adjusted to be 70 to 95%, and particularly preferably adjusted to be 80 to 95%. When the total light transmittance of the first transparent curable resin layer 11 in a cured state is within the above-mentioned numerical range, loss of brightness can be suppressed even if the first transparent curable resin layer 11 remains on the top surfaces of the light emitting elements 21, 22, and 23 during thermocompression bonding.

[0063] [Curable Resin Composition] The first transparent curable resin layer 11 is composed of a curable resin composition. As with the black curable resin layer 10, the curable resin composition can be, for example, a curable resin composition containing at least one resin selected from an epoxy resin, an acrylic resin, a polyester resin, a polyurethane resin, and a silicone resin, and a curing agent. Among these, an epoxy resin composition is preferred because of its excellent heat resistance and reliability.

[0064] (Epoxy Resin) Examples of epoxy resins used in the first transparent curable resin layer 11 include the same types as those used in the black curable resin layer 10. The first transparent curable resin layer 11 preferably does not contain a high-molecular-weight epoxy resin. This makes it easier to ensure sufficient fluidity of the first transparent curable resin layer 11 during thermocompression bonding. When the first transparent curable resin layer 11 contains a high-molecular-weight epoxy resin, the amount of the high-molecular-weight epoxy resin blended is preferably less than 50 parts by mass, more preferably less than 30 parts by mass, and even more preferably less than 10 parts by mass, relative to 100 parts by mass of the total resin solid content of the black curable resin layer 10.

[0065] Furthermore, the epoxy resin used in the first transparent curable resin layer 11 preferably contains a polyfunctional epoxy resin. The polyfunctional epoxy resin can increase the crosslink density, thereby further improving the stability of the performance of the cured product of the epoxy resin composition over long-term use and improving heat resistance.

[0066] Specific examples of polyfunctional epoxy resins include "YX7700", "157S70", and "1032S60" manufactured by Mitsubishi Chemical Corporation, "NC7000L", "XD1000", and "EOCN-1020" manufactured by Nippon Kayaku Co., Ltd., "ESN485" manufactured by Nippon Steel Chemical & Material Co., Ltd., and "N-660", "N-690", "N-695", and "HP-7200H" manufactured by DIC Corporation.

[0067] The amount of the polyfunctional epoxy resin in the first transparent curable resin layer 11 is preferably 90 parts by mass or less, more preferably 10 to 80 parts by mass, and even more preferably 25 to 60 parts by mass, relative to 100 parts by mass of the total resin solid content of the first transparent curable resin layer 11. Within the above range, the storage modulus of the first transparent curable resin layer 11 during thermocompression bonding can be controlled, and heat resistance and chemical resistance can be imparted in the cured state.

[0068] From the viewpoint of ensuring sufficient fluidity during thermocompression bonding, the first transparent curable resin layer 11 preferably contains an epoxy resin having a softening point or melting point of 120° C. or less, and from the viewpoint of handleability and heat resistance of the cured product, more preferably contains an epoxy resin having a softening point or melting point of 50 to 105° C. By containing an epoxy resin having a softening point or melting point within the above range, it becomes possible to control the storage modulus.

[0069] The total amount of epoxy resin in the first transparent curable resin layer 11 is preferably 10 to 100 parts by mass, more preferably 30 to 99 parts by mass, and even more preferably 50 to 95 parts by mass, relative to 100 parts by mass of the total resin solids content of the first transparent curable resin layer 11. When the amount is within the above range, control of the storage modulus is easy. Furthermore, when the amount is within the above range, flow during thermal curing can be suppressed, and poor appearance after curing, such as repellency, can be suppressed. Furthermore, when the amount is equal to or greater than the above lower limit, heat resistance in the cured state can be further improved.

[0070] (Elastomer) The first transparent curable resin layer 11 preferably contains an elastomer in addition to a resin such as an epoxy resin. The inclusion of an elastomer makes it easier to control the storage modulus. Examples of elastomers include the same types as those used for the black curable resin layer 10. Among them, NBR is preferred for the following reasons: NBR has good compatibility with epoxy resins. Furthermore, NBR can increase the storage modulus of the first transparent curable resin layer 11 at around 150°C, thereby improving adhesion between the first transparent curable resin layer 11 and the black curable resin layer 10. The preferred weight-average molecular weight of the elastomer is the same as that of the black curable resin layer 10.

[0071] In particular, when the first transparent curable resin layer 11 is composed of an epoxy resin composition, it preferably contains a modified elastomer having a functional group capable of reacting with an epoxy group. The modified elastomer also acts as a curing agent for the epoxy resin. Furthermore, because it can react and bond with the epoxy resin, it improves heat resistance and reliability against thermal shock. Furthermore, the difference in polarity between the functional group and the resin skeleton favorably affects dispersibility. This allows for good dispersibility when carbon black is incorporated into the first transparent curable resin layer 11.

[0072] Examples of functional groups capable of reacting with an epoxy group include the same types as those of the black curable resin layer 10. Among them, an acid group or an acid anhydride group is preferred, and a carboxy group or a carboxylic acid anhydride group is particularly preferred, because they can be cured at low temperatures and ensure a long usable time.

[0073] When the first transparent curable resin layer 11 is composed of an epoxy resin composition, it particularly preferably contains a modified NBR having a carboxy group. Examples of the modified NBR having a carboxy group include the same types as those used for the black curable resin layer 10. Two or more types of modified elastomers having a functional group reactive with an epoxy group may be used in combination.

[0074] The amount of elastomer in the first transparent curable resin layer 11 is preferably 0 to 50 parts by mass, more preferably 1 to 50 parts by mass, and even more preferably 5 to 50 parts by mass, relative to 100 parts by mass of the total resin solids content of the first transparent curable resin layer 11. Within this range, the storage modulus can be controlled. Furthermore, flow during thermal curing can be suppressed, and poor appearance after curing, such as repellency, can be suppressed. Furthermore, when the amount is equal to or greater than the lower limit, the dispersibility of carbon black is improved. Furthermore, film-forming properties are improved, and the film thickness distribution can be narrowed when the epoxy resin composition is applied to form a film.

[0075] (Curing Agent) When the first transparent curable resin layer 11 is composed of an epoxy resin composition, it may contain, in addition to the modified elastomer having a functional group reactive with an epoxy group, a curing agent for other epoxy resins. Examples of the other curing agent include the same curing agents as those used in the black curable resin layer 10. Two or more types of the other curing agents may be used in combination.

[0076] (Curing Catalyst) When the first transparent curable resin layer 11 is composed of an epoxy resin composition, it may contain a curing catalyst that promotes the curing reaction of the epoxy resin. Examples of the curing catalyst include the same curing catalysts as those used for the black curable resin layer 10, and preferred embodiments are also the same.

[0077] The amount of the curing catalyst is preferably 0.01 to 5 parts by mass, more preferably 0.05 to 4 parts by mass, and even more preferably 0.1 to 3 parts by mass, relative to 100 parts by mass of the total resin solids content of the first transparent curing resin layer 11. Within the above range, curing can be sufficiently promoted, ensuring the usable life of the dry film 1. Two or more types of curing catalysts may be used in combination.

[0078] (Other Components) The first transparent curable resin layer 11 may contain a black pigment to suppress uneven light emission and uneven color.

[0079] When the first transparent curable resin layer 11 contains carbon black, the amount of carbon black is preferably less than 5 parts by mass, more preferably 1 part by mass or less, and even more preferably 0.1 parts by mass or less, relative to 100 parts by mass of the total resin solid content. The first transparent curable resin layer 11 may further contain, as necessary, a resin other than the epoxy resin and the elastomer, a thickener, a defoamer and / or a leveling agent, an adhesion imparting agent such as a coupling agent, and a flame retardant.

[0080] [Film Thickness] The thickness of the first transparent curable resin layer 11 is preferably equal to or greater than the thickness of the black curable resin layer 10. When the thickness of the first transparent curable resin layer 11 is equal to or greater than the thickness of the black curable resin layer 10, the first transparent curable resin layer 11 makes it less likely that the black curable resin layer 10 will remain on the top surfaces of the light emitting elements 21, 22, and 23 during thermocompression bonding. The thickness of the first transparent curable resin layer 11 is not particularly limited, and is preferably 0.05 to 100 μm, more preferably 0.5 to 70 μm, and even more preferably 0.75 to 50 μm.

[0081] (3) Second Transparent Curable Resin Layer The second transparent curable resin layer 12 is a layer having higher light transmittance than the black curable resin layer 10, and is a layer for sufficiently pressing the black curable resin layer 10 and the first transparent curable resin layer 11 between the plurality of light-emitting elements 21, 22, 23 arranged on the element-mounted substrate 2. In this embodiment, the second transparent curable resin layer 12 is formed on the surface of the black curable resin layer 10 opposite to the surface in contact with the first transparent curable resin layer 11. The second transparent curable resin layer 12 is cured through a curing process to become the second transparent resin layer 32 described below. In other words, the second transparent curable resin layer 12 is an uncured layer.

[0082] [Total Light Transmittance] The total light transmittance of the second transparent curable resin layer 12 in a cured state is higher than the total light transmittance of the black curable resin layer 10 in a cured state. The total light transmittance of the second transparent curable resin layer 12 in a cured state is not particularly limited, but is preferably adjusted to be 50% or higher. The total light transmittance is preferably adjusted to be 50 to 95%, more preferably adjusted to be 60 to 95%, even more preferably adjusted to be 70 to 95%, and particularly preferably adjusted to be 80 to 90%. When the total light transmittance of the second transparent curable resin layer 12 in a cured state is within the above-mentioned numerical range, light from the light emitting elements 21, 22, and 23 is not prevented from reaching the viewer's side after being pressure-bonded to the element-mounted substrate 2.

[0083] [Storage Modulus] At 100°C and 150°C, the storage modulus of the second transparent curable resin layer 12 is preferably greater than that of the black curable resin layer 10 at the same temperatures, and more preferably greater than that of the first transparent curable resin layer 11 at the same temperatures. The second transparent curable resin layer 12 may also be referred to as a "high-elasticity transparent curable resin layer." In the present application, "high elasticity" refers to having the highest storage modulus at 100°C among the curable resin layers.

[0084] The storage modulus of the second transparent curable resin layer 12 is preferably greater than the storage modulus of the black curable resin layer 10 and the first transparent curable resin layer 11 at 100 to 150° C. When the storage modulus of the second transparent curable resin layer 12 is greater than the storage modulus of the black curable resin layer 10 and the first transparent curable resin layer 11 at 100° C. and 150° C., the storage modulus of the second transparent curable resin layer 12 is usually greater than the storage modulus of the black curable resin layer 10 and the first transparent curable resin layer 11 over the entire range of 100 to 150° C. Since the storage modulus of the second transparent curable resin layer 12 is greater than the storage modulus of the black curable resin layer 10 and the first transparent curable resin layer 11 at 100°C, the second transparent curable resin layer 12 can appropriately press the first transparent curable resin layer 11 and the black curable resin layer 10 during thermocompression bonding, and the layers 10 and 11 can be sufficiently filled between the light-emitting elements 21, 22, and 23.

[0085] The storage modulus of the second transparent curable resin layer 12 at 100° C. is preferably 1.0×10 ７ Pa or less, and more preferably 1.0 × 10 ４ ~1.0 x 10 ７ Pa, and even more preferably 5.0×10 ４ ~5.0 x 10 ６ It is Pa.

[0086] Since the storage modulus of the second transparent curable resin layer 12 at 100°C is within a preferred numerical range, stress is transmitted to the black curable resin layer 10 and the first transparent curable resin layer 11 when the layer is pressed onto the element-mounted substrate 2, and the layer can have both the elasticity to sufficiently remove the black curable resin layer 10 from above the light-emitting elements 21, 22, and 23, and the flexibility to deform in accordance with the unevenness of the plurality of light-emitting elements 21, 22, and 23. This makes it easier for the first transparent curable resin layer 11 and the black curable resin layer 10 to sufficiently fill in the spaces between the plurality of light-emitting elements 21, 22, and 23.

[0087] When the storage modulus of the second transparent curable resin layer 12 at 100°C is equal to or less than the preferred upper limit, appropriate flexibility is obtained that does not hinder the flow of the first transparent curable resin layer 11 and the black curable resin layer 10 when pressure-bonded to the element-mounted substrate 2. In addition, the spaces between the plurality of light-emitting elements 21, 22, and 23 can be sufficiently filled.

[0088] By having the storage modulus of the second transparent curable resin layer 12 at 100°C equal to or greater than the preferred lower limit, the fluidity of the second transparent curable resin layer 12 can be suppressed, and the surface of the second transparent curable resin layer 12 can be made smoother to fit the light emitting elements 21, 22, and 23 after thermocompression bonding. As a result, the appearance can be improved, and appearance defects such as repellency, which causes depressions on the layer surface during thermal curing, can be made less likely to occur. Furthermore, fluctuations in the film thickness of the black curable resin layer 10 in areas where the light emitting elements 21, 22, and 23 are not present during thermocompression bonding can be suppressed, resulting in an appearance of uniform blackness.

[0089] The storage modulus of the second transparent curable resin layer 12 at 150° C. is preferably 1.0×10 ３ Pa or more, more preferably 1.0 × 10 ３ ~5.0 x 10 ７ Pa, and even more preferably 1.0×10 ３ ~1.0 x 10 ７ It is Pa.

[0090] When the storage modulus of the second transparent curable resin layer 12 at 150°C is equal to or less than the preferred upper limit, cracks due to cure shrinkage are less likely to occur during thermal curing. When the storage modulus of the second transparent curable resin layer 12 at 150°C is equal to or greater than the preferred lower limit, flow of the second transparent curable resin layer 12 during thermal curing can be suppressed, and poor appearance after curing, such as repellency, can be suppressed. Furthermore, problems are less likely to occur when etching is performed in a subsequent process.

[0091] The storage modulus of the second transparent curable resin layer 12 at 100° C. is preferably 10 to 3,000 times, and more preferably 30 to 1,000 times, the storage modulus of the black curable resin layer 10 and the first transparent curable resin layer 11 at 100° C. The storage modulus of the second transparent curable resin layer 12 at 150° C. is preferably 5 to 10,000 times, and more preferably 10 to 1,000 times, the storage modulus of the black curable resin layer 10 and the first transparent curable resin layer 11 at 150° C.

[0092] [Curable Resin Composition] The second transparent curable resin layer 12 is composed of a curable resin composition. As with the black curable resin layer 10 and the first transparent curable resin layer 11, the curable resin composition is preferably an epoxy resin composition because it has excellent heat resistance and reliability.

[0093] (Epoxy Resin) Examples of epoxy resins used in the second transparent curable resin layer 12 include the same types as those used in the black curable resin layer 10 and the first transparent curable resin layer 11. From the viewpoint of imparting an appropriate viscosity during compression bonding to the second transparent curable resin layer 12, the second transparent curable resin layer 12 preferably contains a high-molecular-weight epoxy resin. Furthermore, from the viewpoints of good compatibility with other resin components and being able to dissolve without mixing with a high-boiling-point solvent that may remain in the dry film 1 even after drying, the second transparent curable resin layer 12 more preferably contains a high-molecular-weight epoxy resin having a weight-average molecular weight of 10,000 to 100,000, and even more preferably contains a high-molecular-weight epoxy resin having a weight-average molecular weight of 10,000 to 35,000.

[0094] The second transparent curable resin layer 12 contains a high-molecular-weight epoxy resin with a weight-average molecular weight of 10,000 to 100,000, and therefore has an appropriate viscosity when heated. Therefore, the storage modulus of the second transparent curable resin layer 12 at 100 to 150°C can be adjusted to a preferred range. The high-molecular-weight epoxy resin is preferably a phenoxy resin because of its good compatibility with other epoxy resins.

[0095] Phenoxy resin has a relatively large molecular weight among epoxy resins and exhibits moderate viscosity upon heating. Therefore, the storage modulus of the second transparent curable resin layer 12 containing phenoxy resin can be adjusted within a preferred range within a temperature range of 100 to 150°C. Furthermore, unlike other thermoplastic resins such as polyester, phenoxy resin can be cured as an epoxy resin. Therefore, phenoxy resin increases crosslink density and does not impair the heat resistance or reliability of performance over long periods of use of the cured product. From the viewpoint of ensuring a storage modulus sufficient to compress the black curable resin layer 10 and the first transparent curable resin layer 11 during thermocompression bonding, the glass transition temperature of the phenoxy resin used in the second transparent curable resin layer 12 is preferably 100°C or higher.

[0096] Specific examples of phenoxy resins include "1256," "YX7200," "YX8100," and "YX7180" manufactured by Mitsubishi Chemical Corporation, "YP-50," "YP-50S," and "YP-70" manufactured by Nippon Steel Chemical & Material Co., Ltd., and "N-690," "H-157," and "EXA-192" manufactured by DIC Corporation.

[0097] The blending amount of the high-molecular-weight epoxy resin in the second transparent curable resin layer 12 is preferably 30 to 80 parts by mass, more preferably 40 to 70 parts by mass, and even more preferably 45 to 60 parts by mass, relative to 100 parts by mass of the total resin solid content of the second transparent curable resin layer 12. The same is true for the preferred blending amount of the phenoxy resin in the second transparent curable resin layer 12.

[0098] When the blending amount is within the above range, it becomes easy to control the storage modulus. This ensures a storage modulus sufficient to compress the black curable resin layer 10 and the first transparent curable resin layer 11 during thermocompression bonding. Furthermore, flow during thermal curing can be suppressed, thereby suppressing poor appearance after curing, such as repellency. Furthermore, problems are less likely to occur when etching is performed in a subsequent process. Furthermore, toughness is improved, making it less likely for crack-like defects to occur during thermocompression bonding. When the blending amount is equal to or less than the above upper limit, the crosslink density of the second transparent curable resin layer 12 in the cured state can be increased, improving heat resistance and chemical resistance.

[0099] The other preferred embodiments of the ingredients are the same as those of the first transparent curable resin layer 11 .

[0100] [Film Thickness] The thickness of the second transparent curable resin layer 12 is preferably greater than the thicknesses of the black curable resin layer 10 and the first transparent curable resin layer 11. This allows the black curable resin layer 10 and the first transparent curable resin layer 11 to be uniformly filled between the light emitting elements 21, 22, and 23 during thermocompression bonding. The thickness of the second transparent curable resin layer 12 is not particularly limited, and is preferably 0.05 to 100 μm, more preferably 0.5 to 70 μm, and even more preferably 0.75 to 50 μm.

[0101] (4) Release Sheets The release sheets 17 and 18 have the role of protecting the dry film 1. When forming the dry film 1, the release sheets 17 and 18 can also be used as sheets onto which the coating liquid of the curable resin composition for the first transparent curable resin layer 11 and the second transparent curable resin layer 12 is applied.

[0102] The release sheets 17 and 18 may be sheets made of thermoplastic resins such as polyesters such as polyethylene terephthalate and polyethylene naphthalate, polyimide, polyamide-imide, polyethylene, polytetrafluoroethylene, polypropylene, and polystyrene, or surface-treated paper.

[0103] Among these, polyester sheets are preferably used from the viewpoints of heat resistance, mechanical strength, ease of handling, etc. The thickness of the release sheets 17, 18 is not particularly limited and may be appropriately selected depending on the application within the range of approximately 10 to 150 μm. The surfaces of the release sheets 17, 18 on which the first transparent curable resin layer 11 and the second transparent curable resin layer 12 are provided may be subjected to a release treatment.

[0104] A sheet with a large peel load may be used as the release sheet 18. By using such a release sheet 18, it can be used as a carrier that can hold the second transparent curable resin layer 12 until the curing step.

[0105] 2. Dry Film Manufacturing Method To obtain the dry film 1, first, a release sheet 18 is prepared by coating and drying a coating liquid of the curable resin composition for the second transparent curable resin layer 12, and a release sheet is prepared by coating and drying a coating liquid of the curable resin composition for the black curable resin layer 10. These are overlaid and laminated so that the second transparent curable resin layer 12 and the black curable resin layer 10 are in contact, and the release sheet is peeled off, thereby obtaining a laminate in which the black curable resin layer 10, the second transparent curable resin layer 12, and the release sheet 18 are laminated in this order. Next, a release sheet 17 is prepared by coating and drying a coating liquid of the curable resin composition for the first transparent curable resin layer 11.

[0106] Thereafter, these are stacked and laminated so that the first transparent curable resin layer 11 and the black curable resin layer 10 are in contact with each other, thereby obtaining a laminate in which the first transparent curable resin layer 11, the black curable resin layer 10, the second transparent curable resin layer 12, and the release sheet 18 are stacked in this order on the release sheet 17.

[0107] The coating liquid of the curable resin composition for the black curable resin layer 10, the first transparent curable resin layer 11, and the second transparent curable resin layer 12 preferably contains an organic solvent in an amount sufficient to achieve a viscosity that allows for smooth application. The organic solvent is not particularly limited, but examples thereof include ketones, aromatic hydrocarbons, glycol ethers, glycol ether acetates, esters, alcohols, aliphatic hydrocarbons, and petroleum-based solvents. Specific examples include ketones such as methyl ethyl ketone, cyclohexanone, methyl butyl ketone, and methyl isobutyl ketone; aromatic hydrocarbons such as toluene, xylene, and tetramethylbenzene; glycol ethers such as cellosolve, methyl cellosolve, butyl cellosolve, carbitol, methyl carbitol, butyl carbitol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol diethyl ether, and triethylene glycol monoethyl ether; ethyl acetate, butyl acetate, isobutyl acetate, ethylene glycol monomethyl ether, dipropylene glycol diethyl ether, and triethylene glycol monoethyl ether; and ethyl acetate, butyl acetate, isobutyl acetate, ethylene glycol monomethyl ether, dipropylene glycol diethyl ether, and triethylene glycol monoethyl ether. Examples of suitable solvents include esters such as propylene glycol monoethyl ether acetate, dipropylene glycol methyl ether acetate, propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, and propylene glycol butyl ether acetate; alcohols such as ethanol, propanol, 2-methoxypropanol, n-butanol, isobutyl alcohol, isopentyl alcohol, ethylene glycol, and propylene glycol; aliphatic hydrocarbons such as octane and decane; petroleum solvents such as petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha, and solvent naphtha, as well as N,N-dimethylformamide (DMF), tetrachloroethylene, and turpentine. When carbon black is incorporated into the coating liquid, carbon black powder may be added to the coating liquid, or a liquid in which carbon black has been previously dispersed (carbon black dispersion) may be added.

[0108] Examples of methods for applying the curable resin composition include methods using various coaters such as a die coater, gravure coater, roll coater, curtain flow coater, spin coater, bar coater, reverse coater, kiss coater, fountain coater, rod coater, air doctor coater, knife coater, blade coater, cast coater, screen coater, etc. The drying temperature is preferably 60 to 160°C, more preferably 80 to 130°C, and even more preferably 90 to 120°C.

[0109] The temperature during lamination is preferably 20 to 120°C, more preferably 30 to 100°C, and even more preferably 40 to 80°C. By setting the temperature at or above the preferred lower limit, it is possible to ensure adhesion between the black curable resin layer 10 and the first transparent curable resin layer 11 that allows handling even when uncured. Furthermore, by setting the temperature at or below the preferred upper limit, it is possible to prevent air bubbles from being trapped between the black curable resin layer 10 and the first transparent curable resin layer 11 and the occurrence of wrinkles in the layers 10 and 11. Lamination can be performed using, for example, a roll laminator, a press, a vacuum press, or the like.

[0110] 3. Element-Mounted Substrate The element-mounted substrate 2 is, as shown in Fig. 2, a substrate 20 on which a plurality of light-emitting elements 21, 22, and 23 are arranged. Fig. 2 and other figures schematically show a portion where three light-emitting elements (light-emitting element 21, light-emitting element 22, and light-emitting element 23) are arranged.

[0111] There is no limitation on the material of the substrate 20, but a known printed circuit board can be suitably used, such as an epoxy glass substrate, a fluororesin substrate, a ceramic substrate, or a glass substrate.

[0112] The light-emitting elements 21, 22, and 23 are typically light-emitting diodes. This embodiment is particularly suitable for cases where the light-emitting elements 21, 22, and 23 are extremely small. For example, light-emitting diodes with a height of 1000 nm to 200 μm and a side length of 0.001 to 0.5 mm can be used. The element-mounted substrate 20 for obtaining mini-LEDs or micro-LEDs can use light-emitting diodes of three colors (R, G, and B) or blue light-emitting diodes as the light-emitting elements 21, 22, and 23. Furthermore, the heights of the multiple light-emitting elements 21, 22, and 23 on the substrate 20 do not all have to be the same, and may be different from one another.

[0113] 4. Light-emitting electronic component and manufacturing method thereof A light-emitting electronic component 5 includes an element-mounted substrate 2 having a plurality of light-emitting elements 21, 22, 23 arranged on a substrate 20, and a cured dry film 3 that is pressure-bonded to the surface of the element-mounted substrate 2 on which the plurality of light-emitting elements 21, 22, 23 are arranged.

[0114] The cured dry film 3 includes at least a black resin layer 30 capable of blocking light between the light-emitting elements 21, 22, and 23, and a first transparent resin layer 31 and a second transparent resin layer 32 having higher light transmittance than the black resin layer 30. The first transparent resin layer 31, the black resin layer 30, and the second transparent resin layer 32 are laminated in this order from at least the side in contact with the element-mounted substrate 2. The black resin layer 30, the first transparent resin layer 31, and the second transparent resin layer 32 are layers obtained after curing the black curable resin layer 10, the first transparent curable resin layer 11, and the second transparent curable resin layer 12. The cured dry film 3 according to this embodiment preferably has at least the first transparent resin layer 31 and the black resin layer 30 filled between the light-emitting elements 21, 22, and 23.

[0115] The method for manufacturing a light-emitting electronic component includes the steps of: placing the first transparent curable resin layer 11 side of the dry film 1 on the surface of the element-mounted substrate 2, which has a plurality of light-emitting elements 21, 22, and 23 arranged on a substrate 20, and thermocompression bonding the dry film 1 to fill at least the first transparent curable resin layer 11 and the black curable resin layer 10 between the light-emitting elements 21, 22, and 23 (hereinafter referred to as the thermocompression bonding step); and curing the black curable resin layer 10, the first transparent curable resin layer 11, and the second transparent curable resin layer 12 (hereinafter referred to as the curing step). Hereinafter, a method for manufacturing a light-emitting electronic component according to one embodiment will be described with reference to FIGS. 2 to 4 .

[0116] (i) Thermocompression bonding process In the manufacturing method of this embodiment, first, as shown in FIG. 2, the dry film 1, from which the release sheet 17 has been peeled off to expose the first transparent curable resin layer 11, is placed on the surface of the element-mounted substrate 2 on which the light-emitting elements 21, 22, and 23 are arranged, so that the first transparent curable resin layer 11 is in contact with the surface.

[0117] At this time, that is, before pressure bonding, the thickness of the black curable resin layer 10 is preferably 50% or less of the height of the light emitting elements 21, 22, 23, more preferably 15 to 50%, and even more preferably 30 to 50%.

[0118] The thickness of the black resin layer 30 after curing of the black curable resin layer 10 can be considered to be the same as the thickness of the black curable resin layer 10 before compression and curing, because the change in film thickness before and after compression and curing is small. That is, the thickness of the black resin layer 30 is preferably 50% or less, more preferably 15 to 50%, and even more preferably 30 to 50% of the height of the light-emitting elements 21, 22, and 23. The same applies to the following descriptions regarding the thickness of each curable resin layer.

[0119] When the thickness of the black curing resin layer 10 is 15% or more of the height of the light-emitting elements, the function of blocking light between the light-emitting elements 21, 22, and 23 is sufficient, and the black curing resin layer 10 can be sufficiently filled between the light-emitting elements 21, 22, and 23. When the thickness of the black curing resin layer 10 is 30% or more of the height of the light-emitting elements 21, 22, and 23, the rate of change in film thickness of the black curing resin layer 10 after curing is small, and uniform blackness can be achieved throughout the light-emitting electronic component 5.

[0120] If the thickness of the black curable resin layer 10 is 50% or less of the height of the light-emitting elements 21, 22, and 23, a decrease in brightness can be prevented even if there are differences in the inclination or height of the light-emitting elements 21, 22, and 23, and light from the light-emitting elements 21, 22, and 23 does not reach the viewer. Furthermore, since the black curable resin layer 10 can be made thinner, it is even less likely to remain on the light-emitting elements 21, 22, and 23. Furthermore, the black curable resin layer 10, which has a light-blocking function, can be appropriately filled between the light-emitting elements 21, 22, and 23.

[0121] The thickness of the first transparent curable resin layer 11 before compression bonding is preferably 50% or less, more preferably 15 to 50%, and even more preferably 30 to 50% of the height of the light emitting elements 21, 22, and 23.

[0122] When the thickness of the first transparent curable resin layer 11 is 15% or more of the height of the light-emitting elements, the first transparent curable resin layer 11 can be sufficiently filled between the light-emitting elements 21, 22, and 23. When the thickness of the first transparent curable resin layer 11 is 30% or more of the height of the light-emitting elements 21, 22, and 23, the rate of change in film thickness of the first transparent curable resin layer 11 after curing can be reduced, and a uniform outer shape with fewer irregularities can be achieved throughout the light-emitting electronic component 5.

[0123] When the thickness of the first transparent curable resin layer 11 is 50% or less of the height of the light-emitting element, light blocking by the black curable resin layer 10 can be ensured even if there are differences in the inclination or height of the light-emitting element. In addition, leakage of the first transparent curable resin layer 11 to the outside during thermocompression bonding can be prevented.

[0124] The thickness of the second transparent curable resin layer 12 before compression bonding is preferably 10 to 500% of the height of the light emitting element. The lower limit is more preferably 15% or more, and even more preferably 20% or more. The upper limit is more preferably 200% or less, and even more preferably 150% or less.

[0125] When the thickness of the second transparent curable resin layer 12 is 10% or more of the height of the light-emitting elements 21, 22, and 23, the second transparent curable resin layer 12 can remove the black curable resin layer 10 on the light-emitting elements 21, 22, and 23 during thermocompression bonding. By not leaving the light-blocking black curable resin layer 10 on the light-emitting elements 21, 22, and 23, light from the light-emitting elements 21, 22, and 23 does not reach the viewer. When the thickness of the second transparent curable resin layer 12 is 15% or more of the height of the light-emitting elements 21, 22, and 23, the black curable resin layer 10 and the first transparent curable resin layer 11 can be pressed uniformly together during thermocompression bonding, preventing variations in the black shading due to variations in the film thickness of the flowed black curable resin layer 10. When the thickness of the second transparent cured resin layer 12 is 20% or more of the height of the light-emitting elements 21, 22, and 23, the black cured resin layer 10 and the first transparent cured resin layer 11 can be easily filled sufficiently between the light-emitting elements 21, 22, and 23.

[0126] When the thickness of the second transparent curable resin layer 12 is 500% or less of the height of the light-emitting elements 21, 22, and 23, a uniform film can be formed without differences in residual solvent concentration or unevenness in thermal history in the thickness direction. When the thickness of the second transparent curable resin layer 12 is 200% or less of the height of the light-emitting elements 21, 22, and 23, the fluidity of the second transparent curable resin layer 12 near the upper surface of the light-emitting elements can be increased during thermocompression bonding, allowing the black curable resin layer 10 to be more efficiently removed from above the light-emitting elements 21, 22, and 23. When the thickness of the second transparent curable resin layer 12 is 150% or less of the height of the light-emitting elements 21, 22, and 23, the total light transmittance of the second transparent curable resin layer 12 can be increased.

[0127] The total thickness of the black curable resin layer 10, the first transparent curable resin layer 11, and the second transparent curable resin layer 12 before compression bonding is preferably 100 to 550%, more preferably 110 to 400%, and even more preferably 120 to 300% of the height of the light-emitting element.

[0128] If the total thickness of the black curable resin layer 10, the first transparent curable resin layer 11, and the second transparent curable resin layer 12 is equal to or greater than the lower limit value with respect to the height of the light-emitting elements, the curable resin can be sufficiently embedded between the light-emitting elements 21, 22, and 23. If the total thickness of the black curable resin layer 10, the first transparent curable resin layer 11, and the second transparent curable resin layer 12 is equal to or less than the upper limit value with respect to the height of the light-emitting elements 21, 22, and 23, thickness unevenness is unlikely to occur during pressure bonding, and poor appearance is unlikely to occur on the surface. Furthermore, pressure bias can be prevented, and uniform blackness can be achieved.

[0129] The total thickness of the black curable resin layer 10 and the first transparent curable resin layer 11 before compression bonding is preferably 45 to 130%, more preferably 70 to 115%, and even more preferably 75 to 100% of the height of the light-emitting element. As long as the total thickness of the black curable resin layer 10 and the first transparent curable resin layer 11 before compression bonding is within the above-mentioned numerical range, the thickness of the second transparent curable resin layer 12 filled between the light-emitting elements 21, 22, and 23 can be adjusted to an appropriate range. When the storage modulus of the second transparent curable resin layer 12 at 100°C is higher than that of the other curable resin layers, adjusting the thickness to an appropriate range can further suppress uneven filling of the second transparent curable resin layer 12 between the light-emitting elements 21, 22, and 23 during thermocompression bonding. This ultimately improves the conformability of the entire dry film 1 to the element-mounted substrate 2, allowing for fewer voids to be filled.

[0130] The dry film 1 is subjected to thermocompression bonding in the state shown in FIG. 2 , so that the first transparent curable resin layer 11, the black curable resin layer 10, and a portion of the second transparent curable resin layer 12 are embedded between the light-emitting elements as shown in FIG. 3 . At this time, the black curable resin layer 10 has fluidity ensured by its low storage modulus. Therefore, the black curable resin layer 10 is easily filled between the light-emitting elements 21, 22, and 23, and is easily removed from the top surfaces of the light-emitting elements 21, 22, and 23 by the second transparent curable resin layer 12. The first transparent curable resin layer 11 also has a relatively low storage modulus, ensuring fluidity. Therefore, the first transparent curable resin layer 11 is easily filled between the light-emitting elements 21, 22, and 23. Furthermore, because a certain degree of elasticity is ensured, the first transparent curable resin layer 11 can support the top surfaces of the light-emitting elements 21, 22, and 23 during thermocompression bonding, making it easier to transmit stress during compression to the black curable resin layer 10, thereby further preventing the first transparent curable resin layer 11 from remaining on the top surfaces of the light-emitting elements 21, 22, and 23. On the other hand, the second transparent curable resin layer 12 has a relatively high storage modulus and is kept within a deformable range, so that the black curable resin layer 10 can be easily removed from above the light-emitting elements 21, 22, and 23 even if there are differences in the inclination or height of the light-emitting elements 21, 22, and 23.

[0131] The temperature in thermocompression bonding is preferably 80 to 120°C, and more preferably 90 to 110°C. By setting the temperature in thermocompression bonding to 80°C or higher, it is easy to ensure the fluidity of the black curable resin layer 10 and the first transparent curable resin layer 11 and the flexibility of the second transparent curable resin layer 12. Furthermore, by setting the temperature in thermocompression bonding to 120°C or lower, damage to the light-emitting element is less likely to occur. By setting the temperature in thermocompression bonding to 90 to 110°C, it is possible to more precisely control the fluidity and suppress the occurrence of unevenness and crack-like defects.

[0132] The pressure in the thermocompression bonding is preferably 0.05 to 1.0 MPa, and more preferably 0.1 to 0.5 MPa. By setting the pressure in the thermocompression bonding to a preferred lower limit or higher, the black curable resin layer 10 does not remain on the light emitting elements 21, 22, and 23, and light from the light emitting elements 21, 22, and 23 is not prevented from reaching the viewer. By setting the pressure in the thermocompression bonding to a preferred upper limit or lower, damage to the light emitting elements is unlikely.

[0133] The thermocompression bonding is preferably carried out using a vacuum press that can perform molding in a vacuum state, which makes it easier to avoid defects caused by air being mixed into the light-emitting electronic component 5 obtained.

[0134] (ii) Curing step After the pressure-bonding, the release sheet 18 is peeled off and then the resulting material is thermally cured, so that the black curable resin layer 10 becomes a black resin layer 30 (the black curable resin layer 10 in a cured state), the first transparent curable resin layer 11 becomes a first transparent resin layer 31 (the first transparent curable resin layer 11 in a cured state), and the second transparent curable resin layer 12 becomes a second transparent resin layer 32 (the second transparent curable resin layer 12 in a cured state), as shown in FIG.

[0135] The curing temperature is preferably 100 to 160°C, and more preferably 120 to 150°C. By setting the curing temperature to 100°C or higher, the black curable resin layer 10, the first transparent curable resin layer 11, and the second transparent curable resin layer 12 can be cured. By setting the curing temperature to 120°C or higher, the curing time for the black curable resin layer 10, the first transparent curable resin layer 11, and the second transparent curable resin layer 12 can be shortened. Furthermore, by setting the curing temperature to the above upper limit temperature or lower, damage to the light-emitting element is less likely to occur.

[0136] The curing time varies depending on the curing temperature, but is preferably 30 to 360 minutes, more preferably 45 to 180 minutes. At the curing temperature, the storage modulus of the second transparent curable resin layer 12 is relatively high and fluidity is suppressed, thereby suppressing poor appearance after curing. This results in a light-emitting electronic component 5 in which the dry film cured product 3 is pressure-bonded to the surface of the element-mounted substrate 2 on which the light-emitting elements 21, 22, and 23 are arranged, the element-mounted substrate 2 having the substrate 20 and the light-emitting elements 21, 22, and 23 arranged thereon.

[0137] In the obtained light-emitting electronic component 5, the black curable resin layer 10, the first transparent curable resin layer 11, and the second transparent curable resin layer 12 are cured to form a black resin layer 30, a first transparent resin layer 31, and a second transparent resin layer 32, respectively. Portions of the black resin layer 30, the first transparent resin layer 31, and the second transparent resin layer 32 are filled between the plurality of light-emitting elements 21, 22, and 23. Note that Fig. 4 shows an example in which the black resin layer 30 and the first transparent resin layer 31 are all filled between the plurality of light-emitting elements 21, 22, and 23, and portions of the second transparent resin layer 32 are filled between the plurality of light-emitting elements 21, 22, and 23.

[0138] (Brightness Transmittance) In the present application, the term "brightness transmittance" refers to a transmittance calculated from the brightness of the light-emitting elements 21, 22, and 23 on the element-mounted substrate 2 before and after pressure bonding of the cured dry film 3 (in the case of the second embodiment described below, the integrated encapsulating cured sheet 6). Specifically, the brightness transmittance is determined by measuring the brightness of the light-emitting elements 21, 22, and 23 when lit on the element-mounted substrate 2 before pressure bonding of the cured dry film 3 (hereinafter also referred to as "pre-mounting brightness") and the brightness of the light-emitting electronic component 5 when lit (hereinafter also referred to as "post-mounting brightness"). Then, the brightness transmittance is calculated by substituting each measured value into the following formula (I). That is, the brightness transmittance is calculated by dividing the post-mounting brightness by the pre-mounting brightness. The brightness transmittance is preferably 50% or more, more preferably 60 to 90%, even more preferably 70 to 90%, and particularly preferably 80 to 90%. Brightness Transmittance (%) = (post-mounting brightness / pre-mounting brightness) × 100 (I)

[0139] Second Embodiment Fig. 5 shows a cross-sectional view of an integrated encapsulating sheet and a light-emitting electronic component according to a second embodiment, taken in the same view as Fig. 1. Hereinafter, the contents that overlap with the first embodiment will be omitted.

[0140] 1. Integrated Encapsulating Sheet The integrated encapsulating sheet 4 according to the present embodiment includes the above-described dry film 1, and a protective sheet 15 for encapsulating the light-emitting elements 21, 22, and 23 on the surface of the second transparent curable resin layer 12 opposite to the surface on which the black curable resin layer 10 is laminated, and the first transparent curable resin layer 11, the black curable resin layer 10, the second transparent curable resin layer 12, and the protective sheet 15 are laminated in this order. The integrated encapsulating sheet 4 according to the present embodiment differs from the dry film 1 according to the first embodiment in that the protective sheet 15, which is inseparable after thermal curing, is laminated on the second transparent curable resin layer 12.

[0141] (5) Protective Sheet The protective sheet 15 is a layer or laminate for protecting the light-emitting elements 21, 22, and 23 after thermocompression bonding. In this embodiment, the protective sheet 15 is a laminate in which two layers, a support film layer 14 and a hard coat layer 16, are laminated in this order from the side contacting the surface of the second transparent curable resin layer 12 opposite to the side contacting the black curable resin layer 10. That is, the integrated encapsulating sheet 4 according to this embodiment has at least the first transparent curable resin layer 11, the black curable resin layer 10, the second transparent curable resin layer 12, the support film layer 14, and the hard coat layer 16 laminated in this order. However, the form of the protective sheet 15 is not limited thereto, and it is sufficient that the support film layer 14 is arranged so as to contact the second transparent curable resin layer 12. For example, the protective sheet 15 may be a single layer of only the support film layer 14, or may be a laminate in which three or more identical or different functional layers are laminated.

[0142] [Total Light Transmittance] The total light transmittance of the entire protective sheet 15 (in this embodiment, the combined total of the support film layer 14 and the hard coat layer 16) is preferably 30 to 99%, more preferably 30 to 95%, and even more preferably 40 to 95%. When the total light transmittance of the protective sheet 15 is equal to or greater than the lower limit, light is not prevented from reaching the viewer's side. When the total light transmittance of the protective sheet 15 is equal to or less than the upper limit, it is easier to ensure blackness. When the total light transmittance is within the above range, contrast can be further improved.

[0143] [Storage Modulus] The storage modulus of the entire protective sheet 15 (in this embodiment, the combined support film layer 14 and hard coat layer 16) at 100°C is preferably 1.0 × 10 ８ ~1.0 x 10 １０ Pa, and more preferably 1.0×10 ８ ~9.0 x 10 ９ Pa, and even more preferably 1.0×10 ９ ~8.0 x 10 ９ It is Pa.

[0144] When the storage modulus of the protective sheet 15 at 100°C is equal to or less than the preferred upper limit, the protective sheet 15 has an appropriate flexibility that does not hinder the flow of the black curable resin layer 10 and the like when being pressure-bonded to the element-mounted substrate 2, thereby improving workability and preventing cracks due to pressure.

[0145] When the storage modulus of the protective sheet 15 at 100°C is equal to or greater than the preferred lower limit, the protective sheet 15 is less likely to deform when pressed against the element-mounted substrate 2, and pressure can be reliably transmitted to the black curable resin layer 10 and the like, preventing defects such as cracking and deformation in the hard coat layer 16.

[0146] Each layer that can constitute the protective sheet 15 according to this embodiment will now be described.

[0147] (5-1) Support Film Layer The support film layer 14 is a layer for supporting the second transparent curable resin layer 12. When the above-described protective sheet 15 is a single layer, the support film layer 14 is the same as the protective sheet 15. In this embodiment, the support film layer 14 is formed between the second transparent curable resin layer 12 and the hard coat layer 16.

[0148] [Film Thickness] The thickness of the support film layer 14 is not particularly limited, but is preferably 20 to 300 μm, more preferably 25 to 200 μm, and even more preferably 25 to 100 μm. When the thickness of the support film layer 14 is within the above numerical range, brightness unevenness can be suppressed.

[0149] [Total Light Transmittance] The total light transmittance of the support film layer 14 is preferably adjusted to 30 to 99%, more preferably adjusted to 35 to 95%, and even more preferably adjusted to 40 to 95%. When the total light transmittance of the support film layer 14 is equal to or greater than the lower limit, light is not prevented from reaching the viewer's side.

[0150] The storage modulus of the support film layer 14 at 100° C. is preferably greater than the storage modulus of the black curable resin layer 10 and the transparent curable resin layer 11 in an uncured state at 100° C. The storage modulus of the support film layer 14 is preferably 1.0×10 ８ ~9.0 x 10 ９ Pa, and more preferably 1.0×10 ９ ~8.0 x 10 ９ Pa. When the storage modulus of the support film layer 14 is within this range, the black curable resin layer 10 is less likely to remain on the light emitting elements 21, 22, and 23.

[0151] [Resin] The support film layer 14 may be composed of a thermoplastic resin or a thermosetting resin. Examples of resins constituting the support film layer 14 include polyethylene terephthalate resin, polybutylene terephthalate resin, polyethylene 2,6-naphthalate resin, polyamide resin, polycarbonate resin, polycarbonate copolymer resin, triacetyl cellulose resin, polymethylpentene resin, phenoxy resin, syndiotactic polystyrene resin, and polyimide resin. In terms of heat resistance, weather resistance, availability, cost, and the like, it is preferable to include at least one resin selected from polyethylene terephthalate resin, polyethylene 2,6-naphthalate resin, polycarbonate resin, polycarbonate copolymer resin, and polyamide resin. The inclusion of these resins can prevent deformation during pressure bonding. The support film layer 14 may also contain a black pigment or a light-diffusing filler to suppress uneven light emission and color.

[0152] (5-2) Hard Coat Layer The hard coat layer 16 has a scratch-resistant effect on the support film layer 14 and is a layer for protecting the light-emitting electronic component 5a from scratches, and is an optional component of the protective sheet 15. The hard coat layer 16 may be provided with a release sheet 18 on the surface opposite to the surface that contacts the support film layer 14. The hard coat layer 16 is a cured layer. In this embodiment, the hard coat layer 16 is laminated on the support film layer 14.

[0153] [Surface Hardness] The surface hardness of the hard coat layer 16 is not particularly limited, but is, for example, preferably H or more, more preferably 2H or more, and further more preferably 3H or more in pencil hardness. By providing the hard coat layer 16, the surface hardness of the integrated encapsulating sheet 4 can be increased.

[0154] [Surface Roughness] The surface roughness of the hard coat layer 16 is expressed by the arithmetic mean roughness (Ra). The arithmetic mean roughness (Ra) is preferably 0.1 to 1 μm, more preferably 0.2 to 1 μm, and even more preferably 0.3 to 1 μm. When the Ra of the hard coat layer 16 is equal to or greater than the preferred lower limit, the reflectance of the surface of the hard coat layer 16 can be reduced. When the Ra of the hard coat layer 16 is equal to or less than the preferred upper limit, production can be facilitated.

[0155] [Total Light Transmittance] The hard coat layer 16 is preferably prepared so that the total light transmittance is 30 to 99%, more preferably 50 to 99%, and even more preferably 60 to 99%. When the total light transmittance of the hard coat layer 16 is equal to or greater than the lower limit, light reaching the viewer side is not hindered.

[0156] [Resin] The hard coat layer 16 may be composed of either a thermoplastic resin or a thermosetting resin, and is preferably composed of a thermosetting resin. Examples of the thermosetting resin that constitutes the hard coat layer 16 include acrylic resin, polyurethane resin, silicone resin, melamine resin, etc., and the hard coat layer 16 may contain one or more of these. The hard coat layer 16 may also contain a black pigment.

[0157] [Fine Particles] The hard coat layer 16 may contain fine particles. As the fine particles, inorganic fine particles, organic fine particles, or both can be used. Examples of inorganic fine particles include silica fine particles and titanium fine particles. Examples of organic fine particles include polymethyl methacrylate resin (PMMA resin) and polyurethane resin. Among these, silica fine particles are preferred. By including fine particles, the surface roughness of the hard coat layer 16 can be adjusted and the surface hardness can be improved.

[0158] [Film Thickness] The thickness of the hard coat layer 16 is preferably 1 to 20 μm, more preferably 2 to 10 μm, and even more preferably 3 to 8 μm. When the thickness of the hard coat layer 16 is equal to or greater than the preferred lower limit, sufficient hardness can be ensured. When the thickness of the hard coat layer 16 is equal to or less than the preferred upper limit, defects such as curling do not occur.

[0159] (Other Functional Layers) In addition to the above, the protective sheet 15 may include, for example, a light diffusion layer (not shown) containing a filler to uniformly distribute light from the light emitting elements 21, 22, and 23. The light diffusion layer may be a cured layer or an uncured layer, but is preferably a cured layer. The light diffusion layer may be provided, for example, between the support film layer 14 and the second transparent curable resin layer 12, or may be provided between two support film layers.

[0160] The support film layer 14 may have a colored semitransparent coating layer (not shown) on one or both surfaces. When the support film layer 14 has such a coating layer on the surface farther from the element-mounted substrate 2, i.e., the surface closer to the viewer, diffuse reflection of external light on the support film layer 14 can be made less visible.

[0161] 2. Manufacturing Method of Integrated Encapsulating Sheet In the present embodiment, to obtain the integrated encapsulating sheet 4, first, a sheet (hereinafter also referred to as a second transparent layer laminate sheet) is prepared by coating and drying a coating liquid of a curable resin composition for the second transparent curable resin layer 12 on the surface opposite to the surface on which the hard coat layer 16 has been formed, of the support film layer 14. Further, a sheet (hereinafter also referred to as a black layer laminate sheet) is prepared by coating and drying a coating liquid of a curable resin composition for the black curable resin layer 10 on a release sheet. These sheets are stacked and laminated so that the second transparent curable resin layer 12 and the black curable resin layer 10 are in contact with each other, and the release sheet is peeled off, thereby obtaining a laminate in which the black curable resin layer 10, the second transparent curable resin layer 12, and the protective sheet 15 (support film layer 14 and hard coat layer 16) are sequentially stacked. Next, a sheet (hereinafter also referred to as a first transparent layer laminated sheet) is prepared by applying a coating liquid of a curable resin composition for the first transparent curable resin layer 11 to a release sheet 17 and drying the applied coating liquid.

[0162] These are then stacked and laminated so that the first transparent curable resin layer 11 and the black curable resin layer 10 are in contact with each other, thereby obtaining a laminate in which the first transparent curable resin layer 11, the black curable resin layer 10, the second transparent curable resin layer 12, and the protective sheet 15 (the support film layer 14 and the hard coat layer 16) are laminated in this order on the release sheet 17. A release sheet 18 may be laminated on the outer surface of the hard coat layer 16 as necessary.

[0163] The coating liquid of the curable resin composition, the coating method, and the lamination conditions are the same as those in the first embodiment.

[0164] 3. Element-Mounted Substrate The element-mounted substrate 2 is the same as that in the first embodiment.

[0165] 4. Light-emitting Electronic Component and Manufacturing Method Thereof A light-emitting electronic component 5a according to this embodiment includes an element-mounted substrate 2 in which a plurality of light-emitting elements 21, 22, 23 are arranged on a substrate 20, and an integrated encapsulating cured sheet 6 that is pressure-bonded to the surface of the element-mounted substrate 2 on which the plurality of light-emitting elements 21, 22, 23 are arranged. That is, the light-emitting electronic component 5a differs from the light-emitting electronic component 5 according to the first embodiment in that the light-emitting electronic component 5 includes the integrated encapsulating cured sheet 6 instead of the cured dry film 3.

[0166] The integrated encapsulating cured sheet 6 includes at least a black resin layer 30 capable of blocking light between the light emitting elements 21, 22, and 23, a first transparent resin layer 31 and a second transparent resin layer 32 having higher light transmittance than the black resin layer 30, and a protective sheet 15 for encapsulating the light emitting elements 21, 22, and 23, and is laminated in this order from at least the side in contact with the element-mounted substrate 2: the first transparent resin layer 31, the black resin layer 30, the second transparent resin layer 32, and the protective sheet 15 (in this embodiment, from the side in contact with the second transparent resin layer 32, the support film layer 14 and the hard coat layer 16). The integrated encapsulating cured sheet 6 according to this embodiment preferably fills the spaces between the light emitting elements 21, 22, and 23 with at least the first transparent resin layer 31 and the black resin layer 30.

[0167] The method for manufacturing the light-emitting electronic component 5a according to this embodiment is the same as that of the first embodiment.

[0168] The present invention will be specifically described below with reference to examples, although the present invention is not limited to these examples.

[0169] <Raw Materials> Details of raw materials used in each example and comparative example are as follows.

[0170] [Epoxy resins for curable resin layer] HP-7200H: manufactured by DIC Corporation, cyclopentadiene novolac type multifunctional epoxy resin (solid), softening point 82°C, epoxy equivalent 227 g / eq. jER (registered trademark) YX7200B35: manufactured by Mitsubishi Chemical Corporation, phenoxy resin (MEK solution, solid content 35% by mass), glass transition temperature 150°C, epoxy equivalent 8781 g / eq., weight average molecular weight 27,218 epoxy resin EOCN (registered trademark) 1020-55: manufactured by Nippon Kayaku Co., Ltd., o-cresol novolac type epoxy resin, solid, softening point 55°C, epoxy equivalent 194 g / eq.

[0171] [Elastomer] Nipol (registered trademark) NX775: manufactured by Nippon Zeon Co., Ltd., carboxy-modified nitrile rubber, weight average molecular weight 208,000.

[0172] [Curing catalyst] Curesol (registered trademark) 2PZ-CN: 1-cyanoethyl-2-phenylimidazole, manufactured by Shikoku Chemical Industries, Ltd.

[0173] [Carbon Black] Special Black #4: Gas black manufactured by Orion Engineered Carbons.

[0174] [Solvent] MEK: Methyl ethyl ketone, manufactured by Junsei Chemical Co., Ltd. PGM: Propylene glycol monomethyl ether, manufactured by Junsei Chemical Co., Ltd.

[0175] [Release sheet] 1-TRE: Release film manufactured by Nippa Corporation, thickness 50 μm 1-TR3: Release film manufactured by Nippa Corporation, thickness 50 μm

[0176] <Preparation of Coating Liquid>

[0177] [Coating Liquid for Curable Resin Layer] Table 1 shows the composition of each coating liquid for curable resin layer, as well as the total light transmittance and storage modulus at 100°C in the cured state measured for each coating liquid as a single layer. The units of compositions in the table are parts by mass. The raw materials in the formulations shown in Table 1 were mixed with a solvent of MEK / PGM = 80 / 20 (volume ratio) to prepare coating liquids for curable resin layer (raw materials 1 to 3) with a solids concentration of 35% by mass. That is, the total blend amount (solids content equivalent) of the raw materials below and in the formulations shown in Table 1 was 35% by mass with respect to the entire resulting coating liquid. Raw material 1 was used as the coating liquid for the second transparent curable resin layer, raw material 2-1 or raw material 2-2 as the coating liquid for the black curable resin layer, and raw material 3 as the coating liquid for the first transparent curable resin layer, and each was subjected to the subsequent steps.

[0178] [Raw material 1] - EOCN 1020-55 (50 parts by mass) - YX7200B35 (30 parts by mass) - NX775 (20 parts by mass) - 2PZ-CN (3 parts by mass)

[0179] [Raw materials 2-1] - HP7200H (80 parts by mass) - NX775 (20 parts by mass) - 2PZ-CN (3 parts by mass) - Special Black #4 (8 parts by mass)

[0180] [Raw material 2-2] - HP7200H (90 parts by mass) - NX775 (10 parts by mass) - 2PZ-CN (3 parts by mass) - Special Black #4 (8 parts by mass)

[0181] [Raw material 3-1] - HP7200H (80 parts by mass) - NX775 (20 parts by mass) - 2PZ-CN (3 parts by mass)

[0182] [Raw material 3-2] - HP7200H (60 parts by mass) - NX775 (40 parts by mass) - 2PZ-CN (3 parts by mass)

[0183]

[0184] <Total Light Transmittance of Each Single Layer> The total light transmittance of release PET 1-TRE (manufactured by Nippa Corporation, 50 μm) was measured in accordance with JIS K 7361-1 using a haze meter NDH5000 manufactured by Nippon Denshoku Industries Co., Ltd.

[0185] The first transparent curable resin layer coating liquid, the second transparent curable resin layer coating liquid, and the black curable resin layer coating liquid were each separately applied to the release surface of release PET 1-TRE (Nippa Corporation, 50 μm) using an applicator so that the dry film thickness was 30 μm. After application of each coating liquid, each release PET was dried at 120 ° C for 5 minutes. After drying, the first transparent curable resin layer coating liquid, the second transparent curable resin layer coating liquid, or the black curable resin layer coating liquid was cured by heating for 1 hour in a hot air circulating oven at 150 ° C, thereby obtaining a film with each cured curable resin layer. The total light transmittance of the obtained cured film with each curable resin layer was measured using a haze meter NDH5000 manufactured by Nippon Denshoku Industries Co., Ltd. Thereafter, the total light transmittance of the release PET 1-TRE was set to 100%, and the influence of the release PET was excluded from the measured values ​​of each film with a curable resin layer, and the calculated values ​​are shown in Table 1.

[0186] <Storage modulus of each monolayer> The coating liquid for the first transparent curable resin layer, the coating liquid for the second transparent curable resin layer, and the coating liquid for the black curable resin layer were each applied to the release surface of release PET 1-TRE (manufactured by Nippa Corporation, 50 μm) using an applicator so that the dry film thickness would be 30 μm. After application of each coating liquid, each release PET was dried at 120° C. for 5 minutes. After drying, the release PET 1-TRE was peeled off to obtain monolayer sheets of the first transparent curable resin layer, the second transparent curable resin layer, and the black curable resin layer.

[0187] The storage modulus of each of the obtained single-layer sheets at 100°C was measured using a viscoelasticity measuring device (RSA-G2 manufactured by TA Instruments) under conditions of a measurement frequency of 1 Hz and a temperature rise rate of 5°C / min in accordance with JIS K 7244. The results are shown in Table 1.

[0188] <Substrate with elements for evaluation> A substrate with elements for evaluation was prepared by arranging a plurality of LED light emitting elements, each of which was 0.1×0.2 mm and 65 μm high, on an epoxy glass substrate.

[0189] <Dry film> [Example 1] The coating liquid (raw material 1) for the second transparent curable resin layer shown in Table 2 was applied to the release surface of release PET 1-TR3 (manufactured by Nippa Corporation, 50 μm) using an applicator so as to give a dry film thickness of 40 μm, and the coating was dried at 120°C for 5 minutes to obtain a first sheet in which the second transparent curable resin layer was supported by the release PET.

[0190] The coating liquid for the black curable resin layer (raw material 2-1) was applied to the release surface of release PET 1-TRE (manufactured by Nippa Corporation, 50 μm) using an applicator so that the dry film thickness would be 30 μm, and the coating was dried at 120° C. for 5 minutes to obtain a second sheet in which the black curable resin layer was supported by the release PET.

[0191] The obtained first sheet and second sheet were overlaid so that the black curable resin layer and the second transparent curable resin layer were in contact with each other, and laminated with a roll laminator at 60°C. The release PET 1-TRE used on the second sheet was peeled off to obtain a third sheet.

[0192] Furthermore, the coating liquid (raw material 3) for the first transparent curable resin layer was applied to the release surface of release PET 1-TRE (manufactured by Nippa Corporation, 50 μm) using an applicator so that the dry film thickness would be 30 μm, and the coating was dried at 120° C. for 5 minutes to obtain a fourth sheet in which the first transparent curable resin layer was supported by the release PET.

[0193] The obtained third sheet and fourth sheet were stacked so that the black curable resin layer and the first transparent curable resin layer were in contact with each other, and laminated using a roll laminator at 60°C to obtain a dry film according to Example 1.

[0194] Example 2 The same procedure as in Example 1 was carried out, except that the dry film thickness of the coating liquid for the second transparent curable resin layer was 50 μm and the dry film thickness of the coating liquid for the black curable resin layer was 20 μm.

[0195] [Example 3] The same procedure as in Example 1 was repeated, except that the dry film thickness of the coating liquid for the second transparent curable resin layer was 70 µm, the dry film thickness of the coating liquid for the black curable resin layer was 20 µm, and the dry film thickness of the coating liquid for the first transparent curable resin layer was 10 µm.

[0196] [Example 4] The same procedure as in Example 1 was repeated, except that the dry film thickness of the coating liquid for the second transparent curable resin layer was 30 µm, and the dry film thickness of the coating liquid for the black curable resin layer and the coating liquid for the first transparent curable resin layer was 22.5 µm.

[0197] Example 5 The same procedure as in Example 1 was carried out, except that the dry film thickness of the coating liquid for the second transparent curable resin layer was 30 μm and the dry film thickness of the coating liquid for the black curable resin layer was 40 μm.

[0198] Example 6 The procedure of Example 1 was repeated except that the coating liquid for the black curable resin layer was changed to raw material 2-2.

[0199] Example 7 The same procedure as in Example 6 was carried out, except that the coating liquid for the first transparent curable resin layer was changed to raw material 3-2.

[0200] Example 8 The same procedure as in Example 6 was carried out, except that the coating liquid for the second transparent curable resin layer was changed to raw material 3-1.

[0201] Comparative Example 1 The same procedure as in Example 1 was repeated, except that the coating liquid for the second transparent curable resin layer and the coating liquid for the black curable resin layer were made from raw material 3-1, and the coating liquid for the first transparent curable resin layer was made from raw material 2-1.

[0202] Comparative Example 2 The coating liquid (raw material 1) for the second transparent curable resin layer shown in Table 2 was applied to the release surface of release PET 1-TR3 (manufactured by Nippa Corporation, 50 μm) using an applicator so that the dry film thickness was 40 μm, and the coating was dried at 120° C. for 5 minutes to obtain a first sheet in which the second transparent curable resin layer was supported by the release PET.

[0203] The coating liquid for the black curable resin layer (raw material 2-1) was applied to the release surface of release PET 1-TRE (manufactured by Nippa Corporation, 50 μm) using an applicator so that the dry film thickness would be 50 μm, and the coating was dried at 120° C. for 5 minutes to obtain a second sheet in which the black curable resin layer was supported by the release PET.

[0204] The obtained first sheet and second sheet were stacked so that the second transparent curable resin layer and the black curable resin layer were in contact with each other, and laminated using a roll laminator at 60°C to obtain a dry film according to the comparative example.

[0205] [Mounting of Dry Film] The release PET 1-TRE on the first transparent curable resin layer side of the dry film of each example (the black curable resin layer side in the case of the comparative example) was peeled off, and the first transparent curable resin layer (the black curable resin layer in the case of the comparative example) was placed so that it was in contact with the LED light-emitting element of the substrate with evaluation elements. Thereafter, the dry film was filled between the light-emitting elements in a vacuum press under conditions of a vacuum degree of 100 hPa, 100°C, 0.36 MPa, and 3 minutes, and then heated in an oven at 150°C for 1 hour to be thermally cured, thereby obtaining 10 light-emitting electronic components according to each example.

[0206] [Brightness Transmittance] For the ten light-emitting electronic components of each example, the brightness of the light-emitting element on the substrate with evaluation elements before the dry film was pressed and filled was taken as the pre-mounting brightness, and the brightness of the light-emitting element of the light-emitting electronic component was taken as the post-mounting brightness. The pre-mounting brightness and post-mounting brightness were each measured using a Konica Minolta CA-410 luminance meter, and the brightness transmittance was calculated. The brightness transmittance was calculated using the following formula (I). After measuring and calculating the ten components of each example, the average brightness transmittance for each example was calculated. The calculated average brightness transmittance values ​​are shown in Tables 2 and 3 below. Brightness Transmittance (%) = (Brightness after mounting / Brightness before mounting) × 100 (I)

[0207] [Follow-up ability] For each example, ten light-emitting electronic components were subjected to cross-section polishing using a cross-section polisher (Automet 250, manufactured by Buhler) so that the LED light-emitting elements were visible on the cross-section, and the presence or absence of voids was observed at 1000x magnification using a microscope (product name: VHX-8000, manufactured by Keyence Corporation). The observation results were evaluated according to the following criteria. The evaluation results are shown in Tables 2 and 3 below. A: No voids were observed on the observed cross-section, and the resin was sufficiently filled. B: Although voids were observed on the observed cross-section compared to A, they were within the range of not causing any practical problems.

[0208] Tables 2 and 3 show the structure of each curable resin layer, the average luminance transmittance, and the evaluation results of followability in each Example and Comparative Example. Those with a luminance transmittance of 50% or more were rated as passed, and those with a luminance transmittance of less than 50% were rated as failed.

[0209]

[0210]

[0211] As shown in Tables 2 and 3, it was confirmed that the dry film according to the present invention can maintain a high luminance transmittance and suppress loss of luminance.

[0212] The dry film according to the present invention can be used, for example, as a film for sealing a substrate on which a plurality of light-emitting elements are arranged.

Claims

1. A dry film that is pressure-bonded to a surface of an element-mounted substrate on which a plurality of light-emitting elements are arranged, the dry film including at least: a black curable resin layer for blocking light between the plurality of light-emitting elements; a first transparent curable resin layer that has a higher light transmittance than the black curable resin layer; and a second transparent curable resin layer that has a higher light transmittance than the black curable resin layer, the first transparent curable resin layer, the black curable resin layer, and the second transparent curable resin layer being laminated in this order.

2. The dry film according to claim 1, wherein the storage modulus of the second transparent curable resin layer is greater than the storage modulus of the black curable resin layer at 100°C.

3. A dry film according to claim 1 or 2, wherein the storage modulus of the second transparent curable resin layer is greater than the storage modulus of the first transparent curable resin layer at 100°C.

4. A dry film according to any one of claims 1 to 3, wherein the storage modulus of the first transparent curable resin layer is greater than the storage modulus of the black curable resin layer at 100°C.

5. The storage modulus of the second transparent curable resin layer is 1.0 × 10 at 100°C. ７ The dry film according to claim 1 , wherein the viscosity is 0.05 Pa or less.

6. The storage modulus of the black curable resin layer is 1.0 × 10 at 100°C. ５ The dry film according to claim 1 , wherein the viscosity is 0.05 Pa or less.

7. The storage modulus of the first transparent curable resin layer is 1.0 × 10 at 100°C. ５ The dry film according to claim 1 , wherein the viscosity is 0.05 Pa or less.

8. The storage modulus of the second transparent curable resin layer is 1.0 × 10 at 150°C. ３ The dry film according to claim 1 , wherein the viscosity is 100 Pa or more.

9. The dry film according to any one of claims 1 to 8, wherein the black curable resin layer in a cured state has a total light transmittance of 0 to 30%.

10. A dry film described in any one of claims 1 to 9, wherein the first transparent curable resin layer in a cured state has a total light transmittance of 50% or more.

11. A dry film according to any one of claims 1 to 10, wherein the second transparent curable resin layer in a cured state has a total light transmittance of 50% or more.

12. A dry film described in any one of claims 1 to 11, wherein the thickness of the second transparent curable resin layer is greater than the thickness of the black curable resin layer and the thickness of the first transparent curable resin layer.

13. A dry film according to any one of claims 1 to 12, wherein the thickness of the first transparent curable resin layer is equal to or greater than the thickness of the black curable resin layer.

14. The dry film according to any one of claims 1 to 13, wherein the second transparent curable resin layer contains a high molecular weight epoxy resin.

15. The dry film according to claim 14, wherein the weight average molecular weight of the high molecular weight epoxy resin is 10,000 to 100,000.

16. The dry film according to claim 14 or 15, wherein the second transparent curable resin layer contains a phenoxy resin as the high-molecular-weight epoxy resin.

17. A dry film described in any one of claims 14 to 16, wherein the amount of the high molecular weight epoxy resin blended per 100 parts by mass of the total resin solids content of the second transparent cured resin layer is 30 to 80 parts by mass.

18. The dry film according to any one of claims 1 to 17, wherein the black curable resin layer contains an elastomer.

19. The dry film according to claim 18, wherein the elastomer is a modified elastomer.

20. An integrated encapsulating sheet comprising the dry film according to any one of claims 1 to 19, and a protective sheet for encapsulating the light-emitting element on the surface of the second transparent curable resin layer opposite to the surface on which the black curable resin layer is laminated, in which the first transparent curable resin layer, the black curable resin layer, the second transparent curable resin layer, and the protective sheet are laminated in this order.

21. The integrated encapsulating sheet according to claim 20, wherein the protective sheet comprises at least a support film layer for supporting the second transparent curable resin layer and a hard coat layer for scratch prevention, and the first transparent curable resin layer, the black curable resin layer, the second transparent curable resin layer, the support film layer, and the hard coat layer are laminated at least in this order.

22. A light-emitting electronic component comprising: a substrate with a plurality of light-emitting elements arranged on a substrate; and a cured dry film pressed onto the surface of the substrate with the plurality of light-emitting elements arranged thereon, wherein the cured dry film comprises at least: a black resin layer for shielding light between the plurality of light-emitting elements; a first transparent resin layer having a higher optical transparency than the black resin layer; and a second transparent resin layer having a higher optical transparency than the black resin layer, wherein the first transparent resin layer, the black resin layer, and the second transparent resin layer are laminated in this order from the side in contact with the substrate with elements.

23. The light-emitting electronic component according to claim 22, wherein the thickness of the black resin layer is 50% or less of the height of the plurality of light-emitting elements.

24. A method for manufacturing a light-emitting electronic component, comprising at least the steps of: placing a dry film according to any one of claims 1 to 19 on a surface of an element-mounted substrate on which a plurality of light-emitting elements are arranged, with the first transparent curable resin layer in contact with the surface, and thermocompressing the dry film; and curing the black curable resin layer, the first transparent curable resin layer, and the second transparent curable resin layer by heating.

25. The method for producing a light-emitting electronic component according to claim 24, wherein the temperature during the thermocompression bonding is 80 to 120°C, and the curing is carried out by heating at 100 to 160°C.

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