Dry film, light-emitting electronic component, and method for manufacturing the same

Abstract

The present invention provides a dry film that enhances the blackness of a display when the light-emitting elements are turned off, a light-emitting electronic component using the film, and a method for manufacturing the same. [Solution] The present invention relates to a dry film for pressing onto the surface of an element-equipped substrate on which a plurality of light-emitting elements are arranged, wherein the dry film includes at least a black curable resin layer for shielding light between the plurality of light-emitting elements, and the L*a*b* values ​​obtained by measuring the surface opposite to the surface in contact with the element-equipped substrate when the black curable resin layer is cured are L*: 0 to 20, a*: -2 to 2, and b*: -3 to 3.

Description

[Technical Field]

[0001] The present invention relates to a dry film, a light-emitting electronic component, and a method for manufacturing the same. [Background technology]

[0002] In recent years, displays using extremely small light-emitting diodes, known as mini-LEDs or micro-LEDs, have attracted attention. There are two main methods for using such tiny light-emitting diodes in displays. One method involves arranging a large number of light-emitting diodes on a substrate to form a liquid crystal backlight and locally controlling the brightness of the backlight. The other method involves emitting light from red (R), green (G), and blue (B) light-emitting diodes to send light of each color to the viewer's eye on a pixel-by-pixel basis.

[0003] Light-emitting diodes, such as mini-LEDs or micro-LEDs, are generally placed on a substrate. When multiple light-emitting diodes (referred to as light-emitting elements) are placed on a substrate, it is necessary to shield the space between adjacent light-emitting elements. One known method for shielding the space between multiple light-emitting elements with a light-shielding resin is to use a dry film (see Conventional Art 1 and Patent Document 1). A dry film is, for example, a film obtained by coating and drying a light-shielding resin composition on a protective film.

[0004] When a dry film is pressed onto multiple light-emitting elements on a substrate, a light-shielding resin layer is formed not only in the gaps between the light-emitting elements but also on the top surface (light-emitting surface) of the light-emitting elements. Under these circumstances, this resin layer may block the light that reaches the viewer of the display. To prevent this, the conventional technology 1 described above employs a method in which the light-emitting surface of the light-emitting element is etched by plasma treatment or the like to remove the resin layer on the light-emitting surface, and then the removed surface is covered with a light-transmitting encapsulant.

[0005] However, the above-mentioned conventional technology 1 requires a considerable amount of time for etching, leading to increased manufacturing costs. Furthermore, it is difficult to completely remove the light-shielding resin layer (hereinafter also referred to as the "light-shielding layer") on the light-emitting surface of the light-emitting element, and as a result, it is difficult to completely prevent the diffusion of light that should reach the viewer of the display. In addition, a process of laminating a highly transparent sealing film after the etching process is also required, which adds to the complexity of the manufacturing process.

[0006] To solve the problems of the above-mentioned prior art 1, the inventors of the present invention have developed a novel dry film having a structure in which a curable light-shielding layer and a curable surface layer with higher light transmittance than the curable light-shielding layer are laminated, and the storage modulus of the curable surface layer is greater than that of the curable follow-up layer (see prior art 2 and Patent Document 2). When such a novel dry film is pressed toward the substrate side with the curable light-shielding layer in contact with the top surface side of multiple light-emitting elements, the curable light-shielding layer, which is pressed by the curable surface layer, easily moves between the multiple light-emitting elements due to its relatively small storage modulus. After mounting the dry film to a substrate, curing the curable light-shielding layer and the curable surface layer fills the spaces between the multiple light-emitting elements, and a light-emitting electronic component can be obtained in which the surface layer is positioned on the top surface side of the multiple light-emitting elements. This solves the problems of the above-mentioned prior art 1. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2022-22562 [Patent Document 2] Japanese Patent Publication No. 2024-19872 [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] However, there is still room for improvement in the above-mentioned conventional technology 2. This involves further increasing the blackness of the display when the light-emitting elements are not lit. The market demands displays with higher blackness where the presence of light-emitting elements is difficult to see when the lights are off.

[0009] The present inventors have made this invention to meet such market demands, with the aim of increasing the blackness of the display when the light-emitting elements are turned off. [Means for solving the problem]

[0010] (1) A dry film according to one embodiment for achieving the above objective is a dry film for pressing onto the surface on which a plurality of light-emitting elements are arranged of an element-equipped substrate on which a plurality of light-emitting elements are arranged, The present invention includes at least a black curable resin layer for shielding light between the plurality of light-emitting elements, When the black curable resin layer is in an uncured state, the L*a*b* values ​​obtained by measuring on the surface opposite to the surface in contact with the substrate with the element are L*: 0 to 20, a*: -2 to 2, and b*: -3 to 3. (2) In a dry film according to another embodiment, preferably, the total light transmittance may be 0 to 30% when the black curable resin layer is cured. (3) In a dry film according to another embodiment, preferably the black curable resin layer may contain a black pigment and a dye. (4) In a dry film according to another embodiment, preferably the mass ratio of the black pigment to the dye may be 100:1 to 1:1. (5) In a dry film according to another embodiment, preferably the absorption peak of the dye measured by an ultraviolet-visible spectrophotometer may be in the range of 500 to 650 nm. (6) In a dry film according to another embodiment, preferably the storage modulus of the black curable resin layer at 100°C is 1.0 × 10 5 Please refer to the following below Pa. (7) In the dry film according to another embodiment, preferably, the black curable resin layer may contain an epoxy resin. (8) In the dry film according to another embodiment, preferably, the black curable resin layer may contain an elastomer. (9) In the dry film according to another embodiment, preferably, a transparent curable resin layer having higher light transmittance than the black curable resin layer may be further laminated. (10) In the dry film according to another embodiment, preferably, the storage elastic modulus of the transparent curable resin layer at 100 °C is 1.0×10 3 ~1.0×10 7 Pa. (11) In the dry film according to another embodiment, preferably, the transparent curable resin layer may contain a phenoxy resin. (12) A light-emitting electronic component according to an embodiment for achieving the above object is a substrate with elements having a plurality of light-emitting elements arranged thereon, a cured body of any one of the above dry films in a pressure-bonded state on the surface of the substrate with elements where the plurality of light-emitting elements are arranged, and when the black curable resin layer is in an uncured state, the L*a*b* values measured on the surface opposite to the surface contacting the substrate with elements are L*: 0 to 20, a*: -2 to 2, b*: -3 to 3. (13) In a light-emitting electronic component according to another embodiment, preferably, the cured body of the dry film further includes a transparent resin layer having higher light transmittance than the black resin layer on the side farther from the substrate than the black resin layer after curing of the black curable resin layer. (14) In a light-emitting electronic component according to another embodiment, preferably, the thickness of the transparent resin layer is 0.1 to 5.0 times the height of the plurality of light-emitting elements. (15) A method for manufacturing a light-emitting electronic component according to an embodiment for achieving the above object is A step of disposing any one of the above dry films on a surface of the substrate with a plurality of light-emitting elements, on which the plurality of light-emitting elements are disposed; A step of filling at least a part of the black curable resin between the plurality of light-emitting elements; A step of curing all the curable resin layers including the black curable resin.

Advantages of the Invention

[0011] According to the present invention, the blackness of a display in a state where the light-emitting elements are turned off can be further enhanced.

Brief Description of the Drawings

[0012] [Figure 1] FIG. 1 shows a cross-sectional view of a dry film including a black curable resin layer and a transparent curable resin layer as curable resin layers. [Figure 2] FIG. 2 shows a cross-sectional view similar to FIG. 1 of a dry film including only a black curable resin layer as a curable resin layer. [Figure 3] FIG. 3 shows a cross-sectional view similar to FIG. 1 when the dry film of FIG. 1 is disposed such that its black curable resin layer contacts the top surface of the light-emitting elements of the substrate with elements. [Figure 4] FIG. 4 shows a cross-sectional view similar to FIG. 1 in a state where the dry film is pressure-bonded to the substrate with elements from the stage of FIG. 3 until the black curable resin layer and the transparent curable resin layer of FIG. 1 are embedded between the light-emitting elements. [Figure 5] FIG. 5 shows a cross-sectional view similar to FIG. 1 in a state after further proceeding from the stage of FIG. 4, peeling off the protective sheet on the transparent curable resin layer, and performing a curing treatment.

Embodiments for Carrying Out the Invention

[0013] Next, embodiments of the present invention will be described with reference to the drawings. Note that the embodiments described below are not intended to limit the invention as defined in the claims, and not all 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% or more by mass of the total solid content of the entire composition. In this application, "total resin solids" means the total solid mass of the resin and elastomer, and if a curing agent is added in addition to the elastomer, it also includes the solid mass of the curing agent. A numerical range represented by "~" means a numerical range with the numbers before and after "~" as the lower and upper limits, respectively.

[0014] 1. Dry film (First Embodiment)

[0015] (1) Composition of dry film Figure 1 shows a cross-sectional view of a dry film comprising a black curable resin layer and a transparent curable resin layer as curable resin layers.

[0016] The dry film 1a according to this embodiment shown in Figure 1 is a dry film 1a for pressing onto the surface of an element-equipped substrate 2 on which a plurality of light-emitting elements 21, 22, 23 are arranged, and comprises at least a black curable resin layer 10 that shields light between the plurality of light-emitting elements 21, 22, 23, and a transparent curable resin layer 11 that has higher light transmittance than the black curable resin layer 10. Preferably, the dry film 1a has a form in which the black curable resin layer 10 and the transparent curable resin layer 11 are laminated.

[0017] The dry film 1a is the state of the cured body provided in the light-emitting electronic component 5, described later, before the curing process. The dry film 1a is pressed onto the multiple light-emitting elements 21, 22, and 23 during the placement and filling processes described later. The black curable resin layer 10 and the transparent curable resin layer 11 remain uncured until the curing process described later is performed. That is, the black curable resin layer 10 and the transparent curable resin layer 11 are cured by the curing process to become the black resin layer 30 and the transparent resin layer 31.

[0018] The dry film 1a may further include protective sheets 13, 14 on the outer surface of either or both of the black curable resin layer 10 and the transparent curable resin layer 11 for ease of handling.

[0019] (2) Black curable resin layer The black curable resin layer 10, after curing, becomes a black resin layer 30, which serves to shield light between the light-emitting elements 21, 22, and 23, as well as to improve the contrast of the display. Furthermore, the black curable resin layer 10 is a layer that sufficiently fills the spaces between the multiple light-emitting elements 21, 22, and 23 placed on the substrate 2 with the elements attached by methods such as thermocompression bonding during the placement and filling processes. It also serves to prevent appearance defects caused by the expansion of unfilled voids during curing processes such as thermosetting, and damage to the light-emitting elements 21, 22, and 23 due to external factors in subsequent processes.

[0020] [L*a*b*value] The L*a*b* values ​​of the black curable resin layer 10 are measured in accordance with JIS Z 8781-4:2013, using a light source D65, a field of view of 2°, the reflection method, and the SCE method, on the side opposite to the side in contact with the element-equipped substrate 2, while the black curable resin layer 10 is in an uncured state. The L*a*b* values ​​are preferably L*: 0 to 20, a*: -2 to 2, b*: -3 to 3, more preferably L*: 0 to 15, a*: -1 to 1, b*: -1.5 to 1.5, even more preferably L*: 0 to 12, a*: -0.75 to 0.75, b*: -1 to 1, and particularly preferably L*: 0 to 10, a*: -0.5 to 0.5, b*: -0.5 to 0.5. The above L*a*b* values ​​are measured on a standard white calibration plate. Because the black curable resin layer 10 has a low light transmittance, the influence of the standard white calibration plate is almost negligible. Since the L*a*b* values ​​are within a favorable range, the black curable resin layer 10, after curing, shields light between the light-emitting elements 21, 22, and 23 while not blocking light from the light-emitting elements to the viewer. This allows for a higher blackness of the display when the light-emitting elements are off. Furthermore, by using light-emitting electronic components after curing the dry film 1a, a display with high blackness when the light-emitting elements are off can be achieved. The same indicators apply to the black resin layer 30 after curing.

[0021] [Total light transmittance] In this application, "light transmittance" refers to light transmittance measured by various known methods. For example, it may be the total light transmittance described below. The total light transmittance of the black curable resin layer 10 and the transparent curable resin layer 11 described later in their cured state (i.e., the black resin layer 30 and the transparent resin layer 31) 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, in accordance with JIS K 7361-1, the total light transmittance of the base sheet, for example, the protective sheet 13 described later, is measured using a haze meter (for example, NDH5000 manufactured by Nippon Denshoku Industries Co., Ltd.). Next, a laminated sheet is prepared by laminating the cured black curable resin layer 10 onto the protective sheet 13, and the total light transmittance of the laminated sheet is measured in the same manner. From the obtained total light transmittance of the laminated sheet, a value excluding the influence of the protective sheet 13 is calculated, and this value is taken as the total light transmittance of the black curable resin layer 10 in its cured state. Furthermore, the total light transmittance of the transparent curable resin layer 11 in its cured state can also be obtained by a similar method.

[0022] The total light transmittance in the cured state of the black curable resin layer 10 is adjusted to be 0 to 30%, preferably 1 to 10%, more preferably 1.5 to 5%, even more preferably 2 to 5%, and particularly preferably 2.35% or more and less than 5%. By the total light transmittance being 30% or less, the concealment property after curing can be ensured. By the total light transmittance being 10% or less, the black curable resin layer 10 can achieve sufficient light shielding between the light-emitting elements 21, 22, and 23 after curing. By preventing interference between the light-emitting elements through this light shielding, color unevenness during the light emission of the display can be suppressed. By the total light transmittance being 5% or less, ensuring the blackness degree when the display is not emitting light and suppressing color unevenness when emitting light can be achieved at a high level. Further, by the lower limit value of the total light transmittance being 1% or more, even when the black curable resin layer 10 remains on the top surfaces of the plurality of light-emitting elements 21, 22, and 23 in the filling and curing process, while maintaining the light shielding performance between the light-emitting elements 21, 22, and 23, it does not prevent the light emission of the light-emitting elements 21, 22, and 23 to the viewer side. As a result, color unevenness and luminance loss during the light emission of the display can be suppressed. The total light transmittance in the cured state of the black curable resin layer 10 can be mainly changed by the presence or absence of the blending of the black pigment or dye described later, or its blending amount. Also, the total light transmittance can be changed depending on the thickness of the black curable resin layer 10 and the type of the resin composition.

[0023] [Storage Elastic Modulus] The storage elastic modulus of the black curable resin layer 10 in the uncured state is preferably, at 100 °C, preferably 1.0×10 5 Pa or less, more preferably 1.0×10 1 ~1.0×10 5 Pa, even more preferably 1.0×10 2 ~4.0×10 4 Pa, and particularly preferably 5.0×10 2 ~4.0×10 4 Pa.

[0024] Because the storage modulus of the black curable resin layer 10 is below a preferred upper limit at 100°C, the black curable resin layer 10 exhibits sufficient fluidity when pressed onto the element-equipped substrate 2, and can follow the irregularities of the element-equipped substrate 2 caused by the multiple light-emitting elements 21, 22, 23, and sufficiently fill the spaces between the multiple light-emitting elements 21, 22, 23.

[0025] By ensuring that the storage modulus of the black curable resin layer 10 is above a preferred lower limit at 100°C, pressure unevenness during thermocompression bonding of the black curable resin layer 10 can be prevented, allowing the black curable resin layer 10 to maintain a uniform film thickness during the filling and curing process, and thus maintaining a uniform degree of blackness. Furthermore, it is possible to prevent the resin from flowing out of a predetermined range and ensure the film thickness after bonding.

[0026] The storage modulus of the black curable resin layer 10 in its uncured state is preferably 5.0 × 10 at 150°C. 5 Pa or less, more preferably 5.0 × 10 2 ~5.0×10 5 Pa is more preferably 1.0 × 10 1 ~1.0×10 4 It is Pa.

[0027] The storage modulus of the black curable resin layer 10 is below a preferred upper limit at 150°C, which reduces the likelihood of cracks occurring due to curing shrinkage during thermal curing.

[0028] By having the storage modulus of the black curable resin layer 10 be at or above a preferred lower limit at 150°C, flow during thermal curing can be suppressed, and post-curing appearance defects such as repelling are suppressed.

[0029] [Curable resin composition] (Coloring agent) The black curable resin layer 10 may preferably contain, as a coloring agent, only a black pigment, only a black dye (including a mixture of multiple dyes), or both a black pigment and a dye, in order to exhibit sufficient light-shielding properties after curing. The content of the coloring agent is preferably 5 to 50 parts by mass, more preferably 8 to 17 parts by mass, and even more preferably 10 to 15 parts by mass, per 100 parts by mass of the total resin solids of the black curable resin layer 10. If the content is above the lower limit, sufficient light-shielding properties can be obtained. If the content is below the upper limit, the thixotropy of the black curable resin layer 10 can be reduced, and the fluidity of the black curable resin layer 10 during heat-press bonding can be increased. As a result, the black curable resin layer 10 can sufficiently fill the spaces between the multiple light-emitting elements 21, 22, and 23 of the substrate 2 with the elements. By incorporating the above-mentioned coloring agent into the curable resin composition, the L*a*b* values ​​of the black curable resin layer 10 can be set to the range of L*: 0 to 20, a*: -2 to 2, and b*: -3 to 3. The light-emitting electronic component described later, in which the element-equipped substrate is sealed with a dry film 1a containing this black curable resin layer 10, contributes to the realization of a display that exhibits excellent jet blackness when the light-emitting element is turned off.

[0030] • Black pigment The black pigment, which is a type of coloring agent, may preferably contain carbon black, titanium oxide (titanium black), iron oxide (black iron oxide), etc., and more preferably carbon black. As the carbon black, known carbon blacks such as gas black, channel black, furnace black, thermal black, and lamp black can be used. One or more of these carbon blacks can also be used. In addition, resin-coated carbon black, carbon nanofibers, and carbon nanotubes may be used instead of or in combination with carbon black.

[0031] Among the carbon blacks mentioned above, gas black is preferred because it has many surface functional groups and high dispersibility, allowing it to exhibit sufficient light-shielding properties with only a small amount added. Furthermore, when the black curable resin layer 10 contains a modified elastomer having functional groups that can react with epoxy resin, the interaction between the surface functional groups of the gas black and the functional groups of the modified elastomer with epoxy resin-reactive functional groups further enhances dispersibility, ensuring good light-shielding properties and coating stability.

[0032] ·dye The dye, which is a type of coloring agent, may be either an inorganic dye or / or an organic dye. The dye used in the black curable resin layer 10 may be a dye that exhibits black on its own, or it may be a combination of two or more chromatic dyes that exhibit black. Alternatively, a combination of multiple dyes that exhibit black on their own may be used. As dyes, known dyes such as direct dyes, reactive dyes, sulfur dyes, vat dyes, acid dyes, metal-containing dyes, metal-containing acid dyes, basic dyes, mordant dyes, acid mordant dyes, disperse dyes, and cationic dyes can be used as appropriate. Examples of dyes include complexes of copper, chromium, nickel, cobalt, and azo compounds. Among dyes, bluish-black dyes, such as azine dyes and aniline dyes, are preferred. As an example of such dyes, product number B-20 manufactured by ORIENT CHEMICAL INDUSTRIES, CO., LTD. can be suitably exemplified.

[0033] • Black pigment + dye From the viewpoint of further increasing the blackness in the regions between light-emitting elements of light-emitting electronic components, a combination of a black pigment with high blackness and a dye with high blackness can be used. In particular, when carbon black is used as the black pigment, since carbon black has a slightly yellowish tint, it is necessary to excessively increase the amount of carbon black used to increase the jet blackness. However, by combining it with the aforementioned bluish-tinted black dye, it is possible to increase the blackness while reducing the amount of carbon black used. This makes it possible to control the storage modulus of the black curable resin layer 10, allowing it to exhibit sufficient fluidity when pressed onto the substrate 2 with the elements, and to follow the unevenness of the substrate 2 with the elements caused by the multiple light-emitting elements 21, 22, 23, and sufficiently fill the spaces between the multiple light-emitting elements 21, 22, 23. In this case, it is preferable to use a dye whose absorption peak wavelength in the visible light region of 360 to 800 nm, as measured by an ultraviolet-visible spectrophotometer, is 500 to 650 nm. It is preferable that the amount of black pigment used is greater than or equal to the amount of dye used. The mass ratio of black pigment to dye is preferably 100:1 to 1:1, more preferably 10:1 to 1:1, even more preferably 5:1 to 1:1, and particularly preferably 3:1 to 1.2:1.

[0034] (curable resin) The black curable resin layer 10 comprises a curable resin composition. Examples of curable resin compositions include those comprising 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, epoxy resin compositions that can achieve curability at low temperatures and have excellent heat resistance and reliability are preferred. In this specification, an epoxy resin composition is a composition mainly comprising epoxy resin, or a composition mainly comprising epoxy resin and a curing agent.

[0035] If the black curable resin layer 10 contains an epoxy resin composition, it may also contain a curing agent for epoxy resins other than a modified elastomer having a functional group that can react with epoxy groups. Examples of other curing agents include known curing agents such as phenolic curing agents, acid anhydride curing agents, and amine curing agents. Two or more of these curing agents may be used in combination.

[0036] (Epoxy resin) In this application, an epoxy resin is a compound having epoxy groups in its molecule. The epoxy resin used in this invention is preferably one having two or more epoxy groups in a single molecule. This is because a crosslinked structure can be formed by the reaction with a modified resin having functional groups that can react with epoxy groups, resulting in a cured product with high heat resistance. Furthermore, when an epoxy resin with two or more epoxy groups is used, the degree of crosslinking with the curing agent having functional groups that can react with epoxy groups is sufficient, resulting in a cured product with sufficient heat resistance.

[0037] Examples of epoxy resins include difunctional 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 with a weight-average molecular weight of 10,000 or more. Hydrogenated epoxy resins of these types may also be used. In this application, epoxy resins with a weight-average molecular weight of 10,000 or more are classified as high molecular weight epoxy resins, regardless of the number of epoxy groups in the molecule, and are not classified as difunctional or polyfunctional epoxy resins. The weight-average molecular weight of the epoxy resin is the polystyrene-based molecular weight measured by gel permeation chromatography.

[0038] Examples of epoxy resins include bisphenol A type epoxy resin, bisphenol F type epoxy resin, or phenoxy resins which are high molecular weight versions thereof, and hydrogenated versions thereof; novolac type epoxy resins such as phenol novolac epoxy resin, o-cresol novolac epoxy resin, bisphenol A novolac epoxy resin, xylene structure-containing novolac epoxy resin, naphthol novolac type epoxy resin; glycidyl ester epoxy resins such as diglycidyl phthalate, diglycidyl isophthalate, diglycidyl terephthalate, p-hydroxybenzoate glycidyl ester, diglycidyl tetrahydrophthalate, diglycidyl succinate, diglycidyl adipic acid, diglycidyl sebacate, and triglycidyl trimellitic acid; ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether Examples of epoxy resins include, but are not limited to, glycidyl ether-based epoxy resins such as glycidyl ether, trimethylolpropane triglycidyl ether, pentaerythritol tetraglycidyl ether, tetraphenyl glycidyl ether ethane, triphenyl glycidyl ether ethane, sorbitol polyglycidyl ether, and polyglycerol polyglycidyl ether; 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 resin, phosphorus-containing epoxy resin, fluorine-containing epoxy resin, dicyclopentadiene skeleton-containing epoxy resin, naphthalene skeleton-containing epoxy resin, anthracene type epoxy resin, tert-butylcatechol type epoxy resin, triphenylmethane type epoxy resin, tetraphenylethane type epoxy resin, biphenyl type epoxy resin, and bisphenol S type epoxy resin.

[0039] As high molecular weight epoxy resins, phenoxy resins, epoxy-modified polybutadiene, copolymers of glycidyl methacrylate and methyl methacrylate, and modified polymers obtained by epoxy modification of other resins can be used. These epoxy resins may be used individually or in combination of two or more.

[0040] Among the epoxy resins mentioned above, polyfunctional epoxy resins are preferred for use in the black curable resin layer 10 from the viewpoint of increasing the crosslinking density after curing. Among polyfunctional epoxy resins, novolac-type epoxy resins are particularly preferred for the following reasons. Novolac-type epoxy resins are epoxy resins that can introduce a moderately flexible skeleton and allow for adjustment of flexibility and softening point. As a result, the cured product is less prone to brittle fracture, the stability of the performance of the cured epoxy resin composition for long-term use is improved, and the crosslinking density can be increased. In addition, the heat resistance of the cured product is also improved.

[0041] Specific examples of novolac-type epoxy resins include, for example, "YX7700" from Mitsubishi Chemical Corporation, "NC7000L," "XD1000," and "EOCN-1020" from Nippon Kayaku Kogyo Co., Ltd., "ESN485" from Nippon Steel Chemical & Material Co., Ltd., and "N-660," "N-690," "N-695," and "HP-7200H" from DIC Corporation.

[0042] The amount of polyfunctional epoxy resin blended in the black curable 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, based on 100 parts by mass of the total resin solids content of the black curable resin layer 10. If the amount is above the lower limit, the crosslinking density can be increased to impart chemical resistance and heat resistance. If the amount is below the upper limit, the storage modulus during thermocompression bonding can be adjusted, and the fluidity of the black curable resin layer 10 can be ensured.

[0043] The black curable resin layer 10 preferably does not contain high molecular weight epoxy resin. This makes it easier to ensure sufficient fluidity of the black curable resin layer 10 during heat bonding. When the black curable resin layer 10 contains high molecular weight epoxy resin, the amount of 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, based on 100 parts by mass of the total resin solids content of the black curable resin layer 10.

[0044] From the viewpoint of ensuring sufficient fluidity during thermocompression bonding, the black curable resin layer 10 preferably contains an epoxy resin with a softening point or melting point of 100°C or lower. From the viewpoint of handling properties and heat resistance of the cured product, the black curable resin layer 10 more preferably contains an epoxy resin with a softening point or melting point of 40 to 95°C. Including an epoxy resin having a softening point or melting point within the above range makes it easier to control the storage modulus of the black curable resin layer 10.

[0045] The total amount of epoxy resin in the black curable 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, based on 100 parts by mass of the total resin solids content of the black curable resin layer 10. Within this range, it becomes easier to control the storage modulus of the black curable resin layer 10 and ensure appropriate fluidity during thermocompression bonding. Furthermore, if it is above the lower limit, the heat resistance of the black curable resin layer 10 after curing can be improved.

[0046] (Elastomer) The black curable resin layer 10 preferably contains an elastomer in addition to a resin such as epoxy resin. The inclusion of an elastomer makes it easier to control the storage modulus of the black curable resin layer 10, i.e., control its fluidity. This prevents uneven pressure distribution during the thermocompression bonding of the black curable resin layer 10, and even if the black curable resin layer 10 remains on the top surface of multiple light-emitting elements 21, 22, 23 during the filling and curing process due to differences in the height and inclination of the light-emitting elements, a uniform degree of blackness can be maintained.

[0047] As an elastomer, a thermosetting elastomer, generally called "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. This is because NBR has good compatibility with epoxy resin, making it easy to control the fluidity of the black curable resin layer 10 around 100°C, and as a result, good adhesion between the black curable resin layer 10 and the transparent curable resin layer 11 and the substrate 2 with the element.

[0048] 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. If the weight-average molecular weight of the elastomer is within the above range, it is easier to control the storage modulus of the black curable resin layer 10 and ensure fluidity during thermal bonding. If the weight-average molecular weight of the elastomer is below the above upper limit, the compatibility between the elastomer and the epoxy resin is improved, and the flow of the black curable resin layer 10 during thermal curing can be controlled more effectively.

[0049] In particular, when the black curable resin layer 10 contains an epoxy resin composition, it preferably contains a modified elastomer having a functional group that can react with epoxy groups. The modified elastomer having a functional group that can react with epoxy groups also acts as a curing agent for the epoxy resin. Furthermore, since the modified elastomer can react with and bond to the epoxy resin, the heat resistance and reliability against thermal shock of the black curable resin layer 10 after curing are improved. In addition, the difference in polarity between the functional group that can react with the epoxy resin and the resin skeleton has a good effect on dispersibility, and good dispersibility can be obtained when carbon black is included in the black curable resin layer 10.

[0050] Functional groups that can react with epoxy groups include acidic groups such as carboxyl groups, sulfo groups, nitro groups, and phosphoric acid groups, as well as their acid anhydride groups, hydroxyl groups, and amino groups. Among these, acidic groups or acid anhydride groups are preferred because they allow curing at low temperatures and ensure a long pot life. For similar reasons, carboxyl groups or carboxylic acid anhydride groups are particularly preferred.

[0051] In other words, if the black curable resin layer 10 contains an epoxy resin composition, it preferably contains an acid-modified elastomer having acid groups or acid anhydride groups, more preferably contains an acid-modified elastomer having carboxyl groups, and even more preferably contains modified NBR having carboxyl groups.

[0052] As modified NBR having a carboxyl group, carboxylated acrylonitrile rubber into which acrylic acid, methacrylic acid, maleic anhydride, etc. have been introduced is preferred. Examples of commercially available carboxylated acrylonitrile rubber include "NX775" and "1072CGJ" manufactured by Nippon Zeon Co., Ltd. Two or more modified elastomers having functional groups that can react with epoxy groups may be used in combination.

[0053] 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 6 to 65 parts by mass, based on 100 parts by mass of the total resin solids content of the black curable resin layer 10. Within this range, it becomes easier to control the storage modulus of the black curable resin layer 10 and ensure appropriate fluidity of the black curable resin layer 10 during thermocompression bonding. By ensuring this fluidity, it is possible to prevent pressure unevenness during thermocompression bonding of the black curable resin layer 10, and even if the black curable resin layer 10 remains on the top surface of multiple light-emitting elements 21, 22, 23 during the filling and curing process due to differences in the height and inclination of the light-emitting elements, a uniform blackness can be maintained. Furthermore, if the amount is above the lower limit, the dispersibility of carbon black in the epoxy resin composition improves. In addition, the film-forming properties of the epoxy resin composition are improved, and the distribution of film thickness when coating and forming a film with the epoxy resin composition can be narrowed.

[0054] (Hardening agent) If the black curable resin layer 10 contains an epoxy resin composition, it may also contain a curing agent for epoxy resins other than a modified elastomer having a functional group that can react with epoxy groups. Examples of other curing agents include known curing agents such as phenolic curing agents, acid anhydride curing agents, and amine curing agents. Two or more of these curing agents may be used in combination.

[0055] (curing catalyst) If the black curable resin layer 10 contains an epoxy resin composition, it may also contain a curing catalyst that promotes the curing reaction of the epoxy resin. Examples of curing catalysts include imidazole-based, tertiary amine-based, phosphorus compound-based, and organic peroxide-based catalysts. Among these, imidazole-based or organic peroxide-based catalysts are preferred because they have good compatibility with epoxy resins and are less likely to cause yellowing. Among imidazole-based curing catalysts, those having a cyanoethyl group are particularly preferred because they dissolve easily in epoxy resins.

[0056] Furthermore, when using an organic peroxide as a curing catalyst, for example, benzoyl peroxide, di(2-t-butylperoxyisopropyl)benzene, 2,4-dichlorobenzoyl peroxide, p-methylbenzoyl peroxide, o-methylbenzoyl peroxide, 2,4-dicumyl peroxide, 2,5-dimethylbis(2,5-t-butylperoxy)hexane, di-t-butyl peroxide, t-butyl perbenzoate, and 1,6-hexanediol-bis-t-butyl peroxycarbonate can be suitably used.

[0057] The amount of curing catalyst added is preferably 0.001 to 8 parts by mass, more preferably 0.05 to 5 parts by mass, and even more preferably 0.1 to 4 parts by mass, per 100 parts by mass of the total resin solids of the black curable resin layer 10. When the amount of curing catalyst added is within the above range, curing can be sufficiently advanced and the pot life of the dry film 1a can be ensured. Two or more types of curing catalysts may be used in combination.

[0058] (Other ingredients) The black curable resin layer 10 may contain inorganic fillers to improve flame retardancy and heat resistance, and to adjust the refractive index. The black curable resin layer 10 may also optionally contain resins other than epoxy resin and elastomer, thickeners, defoamers and / or adhesion-enhancing agents such as leveling agents and coupling agents, flame retardants, and refractive index adjusters.

[0059] [film thickness] The thickness of the black curable resin layer 10 is not particularly limited, but is preferably 0.1 to 100 μm, more preferably 1 to 80 μm, and even more preferably 3 to 60 μm.

[0060] (2)Transparent curable resin layer The transparent curable resin layer 11 is a layer that, during compression, sufficiently presses the black curable resin layer 10 between the multiple light-emitting elements 21, 22, and 23 arranged on the element-equipped substrate 2. Furthermore, the transparent curable resin layer 11 becomes a transparent resin layer 31 after curing. As described below, the transparent resin layer 31 exhibits a higher total light transmittance than the black resin layer 30, and therefore blocks almost no light from the light-emitting elements compared to the black resin layer 30.

[0061] [Total light transmittance] The total light transmittance of the transparent curable resin layer 11 in its cured state is higher than that of the black curable resin layer 10 in its cured state. The total light transmittance of the transparent curable resin layer 11 in its cured state is not particularly limited, but is preferably adjusted to be 50-99.9%, more preferably 60-99.9%, and even more preferably 70-99.9%. In this way, the transparent curable resin layer 11 is adjusted to exhibit a very high total light transmittance in its cured state. Therefore, the total light transmittance of the dry film 1a becomes equivalent to that of the black resin layer 30. The relationship between the transparent curable resin layer 11 and the black curable resin layer 10 on the light transmittance of the dry film 1a will be described in detail below.

[0062] [Storage modulus] The storage modulus of the transparent curable resin layer 11 in its uncured state is preferably greater than that of the black curable resin layer 10. Similarly, at 100°C and 150°C, the storage modulus of the transparent curable resin layer 11 is preferably greater than that of the black curable resin layer 10.

[0063] The storage modulus of the transparent curable resin layer 11 is preferably greater than that of the black curable resin layer 10 at 100 to 150°C. If the storage modulus of the transparent curable resin layer 11 is greater than that of the black curable resin layer 10 at 100°C and 150°C, then typically the storage modulus of the transparent curable resin layer 11 is greater than that of the black curable resin layer 10 across the entire temperature range of 100 to 150°C.

[0064] The storage modulus of the transparent curable resin layer 11 is preferably 1.0 × 10 at 100°C. 3 ~1.0×10 7 Pa is 6.0 × 10⁻⁶. 3 ~6.0×10 5 It is Pa.

[0065] By having the storage modulus of the transparent curable resin layer 11 be below a preferred upper limit at 100°C, a moderate flexibility is obtained that does not hinder the flow of the black curable resin layer 10 when it is pressed onto the substrate 2 with the element. In addition, it is possible to adequately fill the spaces between the multiple light-emitting elements 21, 22, and 23.

[0066] By ensuring that the storage modulus of the transparent curable resin layer 11 is above a preferred lower limit at 100°C, the fluidity of the transparent curable resin layer 11 is suppressed, allowing the black curable resin layer 10 to be sufficiently pressed in. Furthermore, the change in the film thickness of the transparent curable resin layer 11 is reduced in areas of the substrate 2 without light-emitting elements 21, 22, and 23. As a result, the film thickness of the black curable resin layer 10 that fluidly fills the space between the transparent curable resin layer 11 and the substrate 20 tends to remain constant, and consequently, the uniformity of the blackness of the light-emitting electronic component 5 on which the dry film 1a is mounted can be improved.

[0067] The storage modulus of the transparent curable resin layer 11 is preferably 1.0 × 10 at 150°C. 3 Pa or higher, more preferably 1.0 × 10⁻⁶ 3 ~5.0×10 7 Pa is more preferably 1.0 × 10 3 ~1.0×10 7 It is Pa.

[0068] By having the storage modulus of the transparent curable resin layer 11 be below a preferred upper limit at 150°C, cracks due to curing shrinkage during thermal curing are less likely to occur.

[0069] Since the storage modulus of the transparent curable resin layer 11 is above a preferred lower limit at 150°C, flow and the generation of bubbles during the thermal curing of the transparent curable resin layer 11 can be suppressed. Furthermore, because the change in film thickness of the transparent curable resin layer 11 during curing is small, it becomes as if the black curable resin layer 10 were placed in a mold, and the flow of the black curable resin layer 10 is restricted, resulting in a smaller change in film thickness. As a result, the uniformity of the blackness of the light-emitting electronic component 5 to which the dry film 1a is pressed can be improved.

[0070] The storage modulus of the transparent curable resin layer 11 is preferably 10 to 1,000 times, and more preferably 30 to 500 times, the storage modulus of the black curable resin layer 10 at 100°C. The storage modulus of the transparent curable resin layer 11 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 at 150°C. If the storage modulus of the transparent curable resin layer 11 is greater than that of the black curable resin layer 10 at 100°C and 150°C, then the storage modulus of the transparent curable resin layer 11 is usually greater than that of the black curable resin layer 10 across the entire temperature range of 100 to 150°C.

[0071] [Curable resin composition] The transparent curable resin layer 11 contains a curable resin composition. Similar to the black curable resin layer 10, the curable resin composition may include at least one resin selected from epoxy resin, acrylic resin, polyester resin, polyurethane resin, and silicone resin, along with a curing agent. Among these, an epoxy resin composition is preferred because it enables curing at low temperatures and exhibits excellent heat resistance and reliability.

[0072] (Epoxy resin) Examples of epoxy resins used in the transparent curable resin layer 11 include those of the same type as those used in the black curable resin layer 10. From the viewpoint of imparting an appropriate storage modulus to the transparent curable resin layer 11 and improving the uniformity of the blackness of the light-emitting electronic component 5, the transparent curable resin layer 11 preferably contains a high molecular weight epoxy resin with a weight-average molecular weight of 10,000 to 100,000. Furthermore, from the viewpoint of good compatibility with other resin components and dissolution without mixing in solvents with high boiling points that may remain on the dry film 1a after drying, the transparent curable resin layer 11 more preferably contains a high molecular weight epoxy resin with a weight-average molecular weight of 10,000 to 35,000.

[0073] The transparent curable resin layer 11 contains a high molecular weight epoxy resin with a weight-average molecular weight of 10,000 to 100,000, and therefore has a suitable viscosity when heated. As a result, the storage modulus of the transparent curable resin layer 11 in the 100 to 150°C range can be adjusted to a preferred range. Consequently, uniformity of blackness can be maintained. The high molecular weight epoxy resin is preferably a phenoxy resin due to its good compatibility with other epoxy resins.

[0074] Phenoxy resin has a relatively high molecular weight among epoxy resins and possesses a suitable viscosity when heated. Therefore, the storage modulus of the transparent curable resin layer 11 containing phenoxy resin in the 100-150°C range can be adjusted to a preferred range. Furthermore, unlike other thermoplastic resins such as polyester, phenoxy resin can be cured as an epoxy resin. Therefore, phenoxy resin can increase the crosslinking density without impairing the heat resistance of the cured product or the reliability of its performance for long-term use. From the viewpoint of ensuring a storage modulus that presses the black curable resin layer 10 during thermocompression bonding, the glass transition temperature of the phenoxy resin used in the transparent curable resin layer 11 is preferably 100°C or higher.

[0075] Specific examples of phenoxy resins include, for example, "1256," "YX7200," "YX8100," and "YX7180" from Mitsubishi Chemical Corporation, "YP-50," "YP-50S," and "YP-70" from Nippon Steel Chemical & Material Corporation, and "H-157" and "EXA-192" from DIC Corporation.

[0076] The amount of high molecular weight epoxy resin in the transparent curable resin layer 11 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, per 100 parts by mass of the total resin solids content of the transparent curable resin layer 11. The preferred amount of phenoxy resin in the transparent curable resin layer 11 is similar.

[0077] By using a compounding ratio within the above range, it becomes easier to control the storage modulus. This ensures that the storage modulus is sufficient to press the transparent curable resin layer 10 during thermocompression bonding. Furthermore, it suppresses flow during thermosetting, preventing post-curing appearance defects such as repulsion. Moreover, it is less likely to cause problems when etching is performed in a subsequent process. In addition, toughness is improved, making it less likely for crack-like defects to occur during thermocompression bonding. Furthermore, if the ratio is below the above upper limit, the crosslinking density of the transparent curable resin layer 11 in the cured state can be increased, improving heat resistance and chemical resistance.

[0078] Furthermore, the epoxy resin used in the transparent curable resin layer 11 preferably includes a polyfunctional epoxy resin. The polyfunctional epoxy resin allows for increased crosslinking density, further improving the stability of the cured epoxy resin composition's performance over long-term use and enhancing its heat resistance. Additionally, the viscosity of the polyfunctional epoxy resin is lower than that of the phenoxy resin in the range of 100-150°C. Therefore, by combining the polyfunctional epoxy resin and the phenoxy resin, the storage modulus of the transparent curable resin layer 11 can be adjusted.

[0079] Specific examples of polyfunctional epoxy resins include, for example, "YX7700," "157S70," and "1032S60" from Mitsubishi Chemical Corporation, "NC7000L," "XD1000," and "EOCN-1020" from Nippon Kayaku Kogyo Co., Ltd., "ESN485" from Nippon Steel Chemical & Material Co., Ltd., and "N-660," "N-690," "N-695," and "HP-7200H" from DIC Corporation.

[0080] The amount of polyfunctional epoxy resin blended in the 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, based on 100 parts by mass of the total resin solids content of the transparent curable resin layer 11. Within this range, the storage modulus of the transparent curable resin layer 11 during thermocompression bonding can be controlled, and heat resistance and chemical resistance can be imparted in the cured state.

[0081] From the viewpoint of ensuring sufficient fluidity during thermocompression bonding, the transparent curable resin layer 11 preferably contains an epoxy resin having a softening point or melting point of 120°C or lower, and more preferably contains an epoxy resin having a softening point or melting point of 50 to 105°C from the viewpoint of handling properties and heat resistance of the cured product. By including an epoxy resin having a softening point or melting point within the above range, it becomes possible to control the storage modulus.

[0082] The total amount of epoxy resin in the 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, based on 100 parts by mass of the total resin solids content of the transparent curable resin layer 11. Within this range, it is easy to control the storage modulus. This ensures that the storage modulus is sufficient to press the black curable resin layer 10 during thermal bonding. Furthermore, within this range, flow during thermal curing can be suppressed, and defects in the appearance after curing, such as repulsion, can be suppressed. Moreover, problems are less likely to occur when etching is performed in a subsequent process. Furthermore, if the amount is above the lower limit, the heat resistance in the cured state is improved.

[0083] (Elastomer) The transparent curable resin layer 11 preferably contains an elastomer in addition to a resin such as epoxy resin. The inclusion of an elastomer facilitates the control of the storage modulus. The elastomer can be the same type as that used in the black curable resin layer 10. Among these, NBR is preferred for the following reasons: NBR has good compatibility with epoxy resin. Furthermore, it can increase the storage modulus of the transparent curable resin layer 11 at around 150°C, resulting in good adhesion between the 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.

[0084] In particular, when the transparent curable resin layer 11 contains an epoxy resin composition, it preferably contains a modified elastomer having a functional group that can react with epoxy groups. This modified elastomer also acts as a curing agent for the epoxy resin. Furthermore, because it can react with and bond to the epoxy resin, it improves heat resistance and reliability against thermal shock. In addition, the difference in polarity between the functional group and the resin backbone has a positive effect on dispersibility. As a result, good dispersibility can be obtained when carbon black is included in the transparent curable resin layer 11.

[0085] Functional groups that can react with epoxy groups include those of the same type as those used in the black curable resin layer 10. Among these, acid groups or acid anhydride groups are preferred, and carboxyl groups or carboxylic acid anhydride groups are particularly preferred, as they allow for curing at low temperatures and ensure a sufficient pot life.

[0086] If the transparent curable resin layer 11 contains an epoxy resin composition, it particularly preferably contains modified NBR having a carboxyl group. Examples of modified NBR having a carboxyl group are the same as those used for the black curable resin layer 10. Two or more modified elastomers having functional groups that can react with epoxy groups may be used in combination.

[0087] The amount of elastomer in the 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, based on 100 parts by mass of the total resin solids in the transparent curable resin layer 11. The elastomer content in the transparent curable resin layer 11 is preferably lower than the elastomer content in the black curable resin layer 10. Within the above range, it is possible to control the storage modulus. Furthermore, if it is below the above upper limit, it is possible to ensure a storage modulus that can press the black curable resin layer 10 during thermal bonding. Furthermore, it is possible to suppress flow during thermal curing and suppress defects in the appearance after curing, such as repelling. Moreover, it is less likely to cause problems when etching is performed in a subsequent process. Furthermore, if it is above the above lower limit, the dispersibility of carbon black is improved. Furthermore, film formation is improved, and the distribution of film thickness when coating and forming an epoxy resin composition can be narrowed.

[0088] (Hardening agent) If the transparent curable resin layer 11 contains an epoxy resin composition, it may also contain other curing agents for epoxy resins in addition to a modified elastomer having a functional group that can react with epoxy groups. Examples of other curing agents include those similar to those used in the black curable resin layer 10. Two or more of these other curing agents may be used in combination.

[0089] (curing catalyst) If the transparent curable resin layer 11 contains an epoxy resin composition, it may also contain a curing catalyst that promotes the curing reaction of the epoxy resin. Examples of curing catalysts include those similar to those used in the black curable resin layer 10, and preferred embodiments are also similar.

[0090] The preferred amount of curing catalyst is the same as in the case of the black curable resin layer 10. Two or more types of curing catalysts may be used in combination.

[0091] (Other ingredients) The transparent curable resin layer 11 may contain black pigment or dye as needed to suppress uneven luminescence and color unevenness.

[0092] When the transparent curable resin layer 11 contains a black pigment or dye, the amount of black pigment or dye is preferably much less than in the case of the black curable resin layer 10. The amount 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, per 100 parts by mass of total resin solids. The transparent curable resin layer 11 may further contain, if necessary, resins other than epoxy resin and elastomer, thickeners, defoamers and / or adhesion-enhancing agents such as leveling agents and coupling agents, flame retardants, and refractive index modifiers.

[0093] [film thickness] The thickness of the transparent curable resin layer 11 is not particularly limited, but is preferably 1 to 100 μm, more preferably 2 to 80 μm, and even more preferably 2 to 60 μm.

[0094] (3) Protective sheet The protective sheets 13 and 14 serve to protect the dry film 1a. They also facilitate the handling of the dry film 1a. Furthermore, protective sheet 13 can be used as a sheet to which a coating liquid of the curable resin composition is applied when manufacturing the dry film 1a, as will be described later.

[0095] As protective sheets 13 and 14, for example, sheets made of polyester such as polyethylene terephthalate or polyethylene naphthalate, thermoplastic resins such as polyimide, polyamide-imide, polyethylene, polytetrafluoroethylene, polypropylene, or polystyrene, or surface-treated paper can be used.

[0096] Among these, polyester sheets are preferably used from the viewpoint of heat resistance, mechanical strength, and ease of handling. The thickness of the protective sheets 13 and 14 is not particularly limited and is generally selected appropriately in the range of 10 to 150 μm depending on the application. The surfaces of the protective sheets 13 and 14 that come into contact with the curable resin layer may be treated with a release agent.

[0097] (Second Embodiment) (1) Composition of dry film Figure 2 shows a cross-sectional view identical to Figure 1 of a dry film having only a black curable resin layer as the curable resin layer.

[0098] (2) Curable resin layer constituting the dry film Dry film 1b comprises only a black curable resin layer 10 as a curable resin layer, and does not have a transparent curable resin layer 11. The black curable resin layer 10, through a combination of black pigment and dye, becomes a black resin layer 30 with a higher degree of blackness than conventional black resin layers after curing. If a thick black resin layer 30 exists on the light-emitting surface of the light-emitting elements 21, 22, and 23, the amount of light emitted from the cured dry film 1b may decrease. For this reason, it is preferable that the black curable resin layer 10 is only slightly thicker than the height of the light-emitting elements 21, 22, and 23. The optical properties, mechanical properties, and composition of the black curable resin layer 10, as well as the protective sheet 13, are the same as in the case of dry film 1a, so redundant explanations are omitted. In dry film 1b, the black curable resin layer 10 can shield the light-emitting elements 21, 22, and 23. Furthermore, since the manufacturing process of dry film 1b does not require the process of laminating the transparent curable resin layer 11, the effort and cost of the manufacturing process can be further reduced.

[0099] 2. Method for manufacturing dry film To obtain the dry film 1a, first, a protective sheet 13 is coated with a coating solution of the curable resin composition for the black curable resin layer 10 and dried (A), and a protective sheet 14 is coated with a coating solution of the curable resin composition for the transparent curable resin layer 11 and dried (B).

[0100] Subsequently, by laminating (A) and (B) above so that the transparent curable resin layer 11 and the black curable resin layer 10 are in contact, a dry film 1a is obtained in which the black curable resin layer 10 and the transparent curable resin layer 11 are sequentially laminated between two protective sheets 13 and 14.

[0101] The coating liquid of the curable resin composition for the black curable resin layer 10 and / or the coating liquid of the curable resin composition for the transparent curable resin layer 11 preferably contains an amount of organic solvent that results in a viscosity that allows for application without hindrance. There are no particular limitations on the organic solvent, but examples include ketones, aromatic hydrocarbons, glycol ethers, glycol ether acetates, esters, alcohols, aliphatic hydrocarbons, and petroleum-based solvents. Specifically, these 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; and ethyl acetate, butyl acetate, isobutyl acetate, and ethyl acetate. Examples of carbon black 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-based solvents such as petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha, and solvent naphtha; and N,N-dimethylformamide (DMF), tetrachloroethylene, and turpentine oil. When incorporating carbon black into a coating solution, carbon black powder may be added to the coating solution, or a pre-dispersed carbon black solution (carbon black dispersion) may be added.

[0102] Methods for applying the above-mentioned curable resin composition include, for example, using various coaters such as die coaters, gravure coaters, roll coaters, curtain flow coaters, spin coaters, bar coaters, reverse coaters, kiss coaters, fountain coaters, rod coaters, air doctor coaters, knife coaters, blade coaters, cast coaters, and screen coaters. The drying temperature is preferably 60 to 160°C, more preferably 80 to 130°C, and even more preferably 90 to 120°C.

[0103] The lamination temperature is preferably 20 to 120°C, more preferably 30 to 100°C, and even more preferably 40 to 80°C. By setting the temperature above the preferred lower limit, sufficient adhesion between the black curable resin layer 10 and the transparent curable resin layer 11 can be ensured, allowing for handling even before curing. Furthermore, by setting the temperature below the preferred upper limit, the trapping of air bubbles between the black curable resin layer 10 and the transparent curable resin layer 11, and the occurrence of wrinkles on each layer 10 and 11 can be prevented. Lamination can be carried out using, for example, a roll laminator, a press, a vacuum press, etc.

[0104] To obtain the dry film 1b, first, a coating liquid of the curable resin composition for the black curable resin layer 10 is applied onto the protective sheet 13. Next, a protective sheet 14 is placed on top of the applied curable resin composition for the black curable resin layer 10, and then the coating liquid is dried. This results in a dry film 1b having protective sheets 13 on both sides of the black curable resin layer 10.

[0105] 3. Circuit board with components Figure 3 shows a cross-sectional view identical to that of Figure 1, when the dry film of Figure 1 is positioned so that its black curable resin layer is in contact with the top surface of the light-emitting element on the substrate with the element.

[0106] As shown in Figure 3, the element-equipped substrate 2 has multiple light-emitting elements 21, 22, and 23 arranged on a substrate 20. Figure 3 schematically shows the portion of the substrate 20 where three light-emitting elements (light-emitting element 21, light-emitting element 22, and light-emitting element 23) are arranged.

[0107] There are no limitations on the material of the substrate 20, but known printed circuit boards can be suitably used. Examples of known printed circuit boards include glass epoxy substrates, fluororesin substrates, ceramic substrates, and glass substrates.

[0108] The light-emitting elements 21, 22, and 23 are typically light-emitting diodes. This embodiment is particularly suitable when 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. For the element-equipped substrate 20 for obtaining mini-LEDs or micro-LEDs, three-color light-emitting diodes of R, G, and B, or a blue light-emitting diode, can be used as the light-emitting elements 21, 22, and 23. In this application, "height of the light-emitting element" refers to the height from the bottom surface to the top surface of the light-emitting element 21, 22, and 23 that are in contact with the substrate 20. Furthermore, the heights of multiple light-emitting elements 21, 22, and 23 on the substrate 20 do not all need to be the same; they may differ individually within the range of manufacturing precision of the element-equipped substrate 2.

[0109] 4. Light-emitting electronic component and method for manufacturing the same Figure 4 shows a cross-sectional view identical to Figure 1, showing the state after the dry film has been pressed onto the substrate with the elements, progressing from the stage in Figure 3 to the point where the black curable resin layer and the transparent curable resin layer in Figure 1 are embedded between the light-emitting elements. Figure 5 shows a cross-sectional view identical to Figure 1, showing the state after further progress from the stage in Figure 4, with the protective sheet on the transparent curable resin layer removed and the curing process performed.

[0110] As shown in Figure 5, the light-emitting electronic component 5 according to this embodiment comprises an element-equipped substrate 2 on which a plurality of light-emitting elements 21, 22, and 23 are arranged, and a cured dry film 1 (1a, 1b) that is pressed onto the surface of the element-equipped substrate 2 on which the plurality of light-emitting elements 21, 22, and 23 are arranged.

[0111] The cured bodies 3 of the dry films 1a and 1b each include a black resin layer 30 that shields the space between multiple light-emitting elements 21, 22, and 23 from the side in contact with the element-equipped substrate 2, and has a total light transmittance of 0 to 30%. Furthermore, the cured body 3 of the dry film 1a further includes a transparent resin layer 31 on top of the black resin layer 30, which has higher light transmittance than the black resin layer 30. The black resin layer 30 and the transparent resin layer 31 are cured layers obtained by heat curing or the like of the black curable resin layer 10 and the transparent curable resin layer 11, respectively. Note that the cured body of the dry film 1a is not limited to a configuration in which these layers are continuously laminated without other layers in between, and may include various functional layers in different cured states between each layer.

[0112] The thickness of the black resin layer 30 contained in the dry film 1a is not particularly limited, but is preferably 0.1 to 0.9 times the height of the multiple light-emitting elements 21, 22, and 23. The thickness of the transparent resin layer 31 is not particularly limited, but is preferably 0.1 to 5.0 times the height of the multiple light-emitting elements 21, 22, and 23.

[0113] The method for manufacturing a light-emitting electronic component according to this embodiment includes the steps of: placing the black curable resin layer 10 side of the dry film 1 on the surface on which the multiple light-emitting elements 21, 22, 23 are arranged on the element-equipped substrate 2, which has multiple light-emitting elements 21, 22, 23 arranged on the substrate 20, and starting the pressing process (hereinafter referred to as the placement step); continuing the pressing process to fill at least a portion of the black curable resin layer 10 between the multiple light-emitting elements 21, 22, 23 (hereinafter referred to as the filling step); and curing all curable resin layers, including the black curable resin layer (hereinafter referred to as the curing step). The method for manufacturing a light-emitting electronic component according to one embodiment (also simply referred to as the "manufacturing method according to one embodiment") when using dry film 1a will be described below with reference to Figures 3 to 5. Note that when using dry film 1b, the same manufacturing method as when using dry film 1a can be adopted in which the black curable resin layer 10 is placed on the top surface of the light-emitting elements 21, 22, 23 and sealed while being pressed in the direction of the substrate 20.

[0114] (i) Placement process In the manufacturing method of this embodiment, first, the protective sheet 13 is peeled off to expose the black curable resin layer 10, and as shown in Figure 3, the black curable resin layer 10 is brought into contact with the surface of the element-equipped substrate 2 on which the light-emitting elements 21, 22, and 23 are arranged, and the pressing of the dry film 1a is started.

[0115] Before crimping, the thickness of the black curable resin layer 10 is preferably 10 to 95% of the height of the light-emitting elements 21, 22, and 23. The lower limit is more preferably 15% or more, and even more preferably 30% or more. The upper limit is more preferably 85% or less, and even more preferably 75% or less.

[0116] If the thickness of the black curable resin layer 10 is 10% or more of the height of the light-emitting elements 21, 22, and 23, the function of shielding light between the light-emitting elements 21, 22, and 23 is sufficient. Also, if the storage modulus of the black curable resin layer 10 is relatively low and the layer 10 is highly fluid, the resin can be sufficiently filled between the light-emitting elements 21, 22, and 23. If the thickness of the black curable resin layer 10 is 15% or more of the height of the light-emitting elements 21, 22, and 23, crack-like defects are less likely to occur on the surface even if the fluidity of the transparent curable resin layer 11 is relatively low. If the thickness of the black curable resin layer 10 is 30% or more of the height of the light-emitting elements 21, 22, and 23, the black curable resin layer 10 with light-shielding function can be appropriately filled between the light-emitting elements 21, 22, and 23.

[0117] If the thickness of the black curable resin layer 10 is 95% or less of the height of the light-emitting elements 21, 22, and 23, leakage of the black curable resin layer 10 to the outside during thermocompression bonding can be prevented, and it is less likely that light from the light-emitting elements 21, 22, and 23 will reach the viewer. If the thickness of the black curable resin layer 10 is 85% or less of the height of the light-emitting elements 21, 22, and 23, variations in the film thickness of the black curable resin layer 10 that has flowed after pressing are less likely to occur, and variations in the shade of black are less likely to occur. If the thickness of the black curable resin layer 10 is 75% or less of the height of the light-emitting elements 21, 22, and 23, the black curable resin layer 10 with light-shielding function can be appropriately filled between the light-emitting elements 21, 22, and 23.

[0118] The thickness of the transparent curable resin layer 11 before pressure bonding is preferably 10 to 500% of the height of the light-emitting elements 21, 22, and 23. The lower limit is more preferably 20% or more, and even more preferably 30% or more. The upper limit is more preferably 200% or less, and even more preferably 150% or less.

[0119] If the thickness of the transparent curable resin layer 11 is 10% or more of the height of the light-emitting elements 21, 22, and 23, it is likely to function as a sealing layer covering the light-emitting elements 21, 22, and 23. Furthermore, if the storage modulus of the transparent curable resin layer 11 is relatively high and its fluidity is suppressed, it is possible to suppress the flow of the transparent curable resin layer 11 together with the black curable resin layer 10 during thermal curing, making it less likely for surface defects to occur. If the thickness of the transparent curable resin layer 11 is 20% or more of the height of the light-emitting elements 21, 22, and 23, there is a sufficient range to allow the flow of the transparent curable resin layer 11, making it less likely for crack-like defects to occur on the surface. If the thickness of the transparent curable resin layer 11 is 30% or more of the height of the light-emitting elements 21, 22, and 23, the transparent curable resin layer 11 is likely to function as a sealing layer covering the light-emitting elements 21, 22, and 23. Furthermore, if the storage modulus of the transparent curable resin layer 11 is relatively high and the fluidity of the layer 11 is suppressed, the transparent curable resin layer 11 can sufficiently press the black curable resin layer 10 into it.

[0120] The combined thickness of the black curable resin layer 10 and the transparent curable resin layer 11 before lamination is preferably 110-550% of the height of the light-emitting elements 21, 22, and 23. If the combined thickness is greater than or equal to the lower limit of the height of the light-emitting elements 21, 22, and 23, a portion of the dry film 1 can be sufficiently embedded between the light-emitting elements 21, 22, and 23. If the combined thickness is less than or equal to the upper limit of the height of the light-emitting elements 21, 22, and 23, thickness unevenness is less likely to occur during lamination, and surface defects are less likely to occur.

[0121] The ratio of the thickness of the black curable resin layer 10 before pressing to the total thickness of the transparent curable resin layer 11 and the black curable resin layer 10 before pressing is preferably 10 to 90%, and more preferably 15 to 70%. If this ratio of thickness is above the lower limit, the blackness can be increased and the contrast of the display can be sufficiently improved. If this ratio of thickness is below the upper limit, less of the black curable resin layer 10 will remain on the light-emitting elements 21, 22, and 23 during pressing, and the brightness can be sufficiently improved.

[0122] In the case of a dry film 1b comprising only a black curable resin layer 10 as the curable resin layer, the thickness of the black curable resin layer 10 before lamination is preferably 110 to 150% of the height of the light-emitting elements 21, 22, and 23. If this thickness is greater than or equal to the lower limit of the height of the light-emitting elements 21, 22, and 23, a portion of the dry film 1b can be sufficiently embedded between the light-emitting elements 21, 22, and 23. If this thickness is less than or equal to the upper limit of the height of the light-emitting elements 21, 22, and 23, the risk of reduced light emission outside the cured dry film 1b can be suppressed. (ii) Filling process Next, the pressing is continued, and at least a portion of the black curable resin layer 10 of the dry film 1a is embedded between the light-emitting elements 21, 22, and 23, as shown in Figure 4. At this time, the black curable resin layer 10 is filled between the multiple light-emitting elements 21, 22, and 23. If the storage modulus of the black curable resin layer 10 is relatively low and the fluidity of the layer 10 is ensured, the black curable resin layer 10 will easily follow the irregularities caused by the light-emitting elements 21, 22, and 23 and be filled between the light-emitting elements 21, 22, and 23.

[0123] The temperature during thermocompression bonding is preferably 80 to 120°C, more preferably 90 to 110°C. Setting the temperature to 80°C or higher makes it easier to ensure the fluidity of the black curable resin layer 10 of the dry film 1. Setting the temperature to 120°C or lower makes it less likely to damage the light-emitting elements 21, 22, and 23. Setting the temperature to 90 to 110°C allows for more precise control of the fluidity of the black curable resin layer 10, suppressing the occurrence of unevenness and crack-like defects.

[0124] The pressure used in thermocompression bonding is 0.05 to 5.0 MPa, preferably 0.05 to 1.0 MPa, and more preferably 0.1 to 0.5 MPa. By setting the pressure above the preferred lower limit, the black curable resin layer 10 can be sufficiently filled between the light-emitting elements 21, 22, and 23. By setting the pressure below the preferred upper limit, damage to the light-emitting elements 21, 22, and 23 is minimized. Thermocompression bonding is preferably performed using a vacuum press capable of molding under vacuum. This makes it easier to avoid defects caused by air being mixed into the resulting light-emitting electronic component 5.

[0125] (iii) Curing process After pressing, as shown in Figure 5, the protective sheet 14 is peeled off and then heat-cured to form the black curable resin layer 10 and the transparent curable resin layer 11 of the dry film 1 into a black resin layer 30 (cured layer of the black curable resin layer 10) and a transparent resin layer 31 (cured layer of the transparent curable resin layer 11).

[0126] The curing temperature is preferably 100 to 160°C, and more preferably 110 to 150°C. By setting the curing temperature to 100°C or higher, the black curable resin layer 10 and the transparent curable resin layer 11 of the dry film 1 can be reliably cured. By setting the curing temperature to 110°C or higher, the curing time of the black curable resin layer 10 and the transparent curable resin layer 11 can be shortened. Furthermore, by setting the curing temperature below the above upper limit temperature, damage to the light-emitting elements 21, 22, and 23 is less likely to occur.

[0127] The curing time depends on the curing temperature, but is preferably 30 to 360 minutes, and more preferably 45 to 180 minutes. If the storage modulus of the transparent curable resin layer 11 is relatively high and the fluidity of the layer 11 is suppressed at the curing temperature, then defects in the appearance of the black curable resin layer 10 and the transparent curable resin layer 11 after curing can be suppressed.

[0128] In the manufacturing method of this embodiment, a dry film 1b can also be used (not shown). The dry film 1b does not have a transparent curable resin layer 11. The thickness of the black curable resin layer 10 before pressing and the pressing conditions are the same as when using dry film 1a, so a description is omitted.

[0129] As described above, through the process shown in Figures 3 to 5, a light-emitting electronic component 5 is obtained by pressing dry films 1a and 1b onto the surface of the element-equipped substrate 2 on which the multiple light-emitting elements 21, 22, and 23 are arranged on the substrate 20. In the obtained light-emitting electronic component 5, the black curable resin layer 10 and / or the transparent curable resin layer 11 harden to become a black resin layer 30 and / or a transparent resin layer 31. [Examples]

[0130] The present invention will be described in detail below with reference to examples. However, the present invention is not limited to these examples.

[0131] <Raw materials> The details of the raw materials used in each example and comparative example are as follows.

[0132] [Epoxy resin for curable resin layers] EOCN 1020-55: Manufactured by Nippon Kayaku Kogyo Co., Ltd., cresol novolac type epoxy resin, solid, softening point 55°C, epoxy equivalent 194 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 30,000. HP-7200H: Manufactured by DIC Corporation, cyclopentadiene novolac type polyfunctional epoxy resin (solid), softening point 82°C, epoxy equivalent 227 g / eq.

[0133] [Elastomer] NX775: Manufactured by Zeon Corporation, carboxy-modified nitrile rubber, weight-average molecular weight 208,000.

[0134] [Curing catalyst] • 2PZ-CN: Manufactured by Shikoku Chemicals Holdings Co., Ltd., 1-cyanoethyl-2-phenylimidazole.

[0135] [Pigments] • Special Black 4: Gas black manufactured by ORION ENGINEERED CARBONS.

[0136] [dye] • B-20: Manufactured by ORIENT CHEMICAL INDUSTRIES, CO., LTD., with an absorption peak wavelength of 583 nm in the visible light region of 360-800 nm.

[0137] [solvent] • MEK: Methyl ethyl ketone, manufactured by Junsei Chemical Co., Ltd. PGM: Propylene glycol monomethyl ether, manufactured by Junsei Chemical Co., Ltd.

[0138] <Preparation of coating solution for dry film> The raw materials in the formulations shown in Table 1 (on a solids basis) were mixed with a solvent of MEK / PGM = 80 / 20 (volume ratio) to prepare a coating solution with a solids concentration of 25% by mass. That is, the total amount of the raw materials in the formulations shown in Table 1 (on a solids basis) was set to 25% by mass of the total amount of the resulting coating solution.

[0139] Table 1 shows the raw material compositions for the black curable resin layer and the transparent curable resin layer used in each example and comparative example. Raw materials 1-1 and 1-2 are the raw material compositions for the transparent curable resin layer, and raw materials 2-1 to 2-5 are the raw material compositions for the coating liquid for the black curable resin layer. In Table 1, each value in the raw material composition represents parts by mass, where 1 part by mass = 1 g.

[0140] [Table 1]

[0141] <Example 1> [Preparation of a transparent curable resin layer] A coating liquid for a transparent curable resin layer (raw material 1-1, see Table 1) was applied to the release surface of a release PET sheet 1-TR3 (manufactured by Nippa Co., Ltd., 50 μm) using a bar coater to a dry film thickness of 3 μm. After drying at 100°C for 5 minutes, a sheet of transparent curable resin layer supported on the release PET sheet was obtained.

[0142] [Preparation of a black curable resin layer] A coating liquid for a black curable resin layer (raw material 2-1, see Table 1) was applied to the release surface of a release PET sheet 1-E (manufactured by Nippa Co., Ltd., 50 μm) using a bar coater to a dry film thickness of 5 μm. After drying at 100°C for 5 minutes, a sheet of black curable resin layer supported on the release PET sheet was obtained.

[0143] [Dry film production] The obtained transparent curable resin layer sheet and the black curable resin layer sheet were stacked so that the transparent curable resin layer and the black curable resin layer were in contact with each other, and laminated in a roll laminator at 60°C to obtain the dry film of Example 1.

[0144] <Example 2> A dry film was prepared using the same conditions as in Example 1, except that the coating liquid for the transparent curable resin layer was changed from raw material 1-1 to raw material 1-2 (see Table 1).

[0145] <Example 3> A dry film was prepared using the same conditions as in Example 1, except that the coating liquid for the black curable resin layer was changed from raw material 2-1 to raw material 2-2 (see Table 1).

[0146] <Example 4> A dry film was prepared using the same conditions as in Example 1, except that the coating liquid for the black curable resin layer was changed from raw material 2-1 to raw material 2-3 (see Table 1).

[0147] <Comparative Example 1> A dry film was prepared under the same conditions as in Example 1, except that the coating liquid for the transparent curable resin layer was changed from raw material 1-1 to raw material 1-2 (see Table 1), and the coating liquid for the black curable resin layer was changed from raw material 2-1 to raw material 2-4 (see Table 1).

[0148] <Comparative Example 2> A dry film was prepared under the same conditions as in Example 1, except that the coating liquid for the transparent curable resin layer was changed from raw material 1-1 to raw material 1-2 (see Table 1), and the coating liquid for the black curable resin layer was changed from raw material 2-1 to raw material 2-5 (see Table 1).

[0149] <Evaluation of each example and each comparative example> [Measurement of Storage Modulus]

[0150] The storage modulus at 100°C for the black curable resin layer and the transparent curable resin layer was measured in accordance with JIS K7244 using a viscoelasticity measuring device (RSA-G2, TA Instruments) under conditions of a measurement frequency of 1 Hz and a heating rate of 5°C / min. Specifically, the coating solution for the transparent curable resin layer was applied to the release surface of release PET 1-TR3 (Nippa Co., Ltd., 50 μm) using a bar coater to a dry film thickness of 50 μm, and then dried at 100°C for 5 minutes. Similarly, the coating solution for the black curable resin layer was applied to the release surface of release PET 1-E (Nippa Co., Ltd., 50 μm) using a bar coater to a dry film thickness of 50 μm, and then dried at 100°C for 5 minutes. After drying, the single-layer films of the various curable resin layers obtained by removing the release PET were subjected to measurement.

[0151] [Measurement of total light transmittance] Samples for measuring total light transmittance were prepared as follows: A coating solution for various transparent curable resin layers was applied to the release surface of release PET 1-TR3 using a bar coater to a dry film thickness of 3 μm. Similarly, a coating solution for various black curable resin layers was applied to the release surface of release PET 1-E using a bar coater to a dry film thickness of 5 μm. These were dried at 120°C for 5 minutes, then heated at 150°C for 1 hour to obtain various cured films with release PET attached. The total light transmittance of each cured film (black curable resin layer and transparent curable resin layer) was measured using a haze meter (NDH5000, manufactured by Nippon Denshoku Industries Co., Ltd.) in accordance with JIS K 7361-1. Measurements were performed on the cured films of various curable resin layers formed as single layers on the release PET, and on the release PET alone. The total light transmittance of each cured film is the value excluding the effect of the release PET.

[0152] [Measurement of L*a*b* values] The L*a*b* values ​​of the black curable resin layer were measured in accordance with JIS Z 8781-4 using a Konica Minolta CR-5 colorimeter with a light source of D65, a field of view of 2°, the reflection method, and the SCE method. Samples for measurement were prepared by applying various coatings for black curable resin layers to the release surface of a release PET 1-E (manufactured by Nippa Co., Ltd., 50 μm) using a bar coater to a dry film thickness of 5 μm, and drying at 120°C for 5 minutes. The L*a*b* values ​​were measured on the coated surface of the black curable resin layer, i.e., the surface opposite to the side in contact with the substrate.

[0153] [Evaluation of uniformity of blackness] An evaluation substrate was prepared by forming multiple 30 x 30 μm copper patterns, each 7 μm high, at 0.2 mm intervals on a 50 mm x 50 mm planar polyimide (PI) substrate with a thickness of 125 μm.

[0154] For the dry films prepared in each of the above examples and comparative examples, the release PET 1-E on the black curable resin layer side was peeled off. The dry film with the exposed black curable resin layer was positioned so that the black curable resin layer was in contact with the LED light-emitting element. Then, the dry film was pressed onto the evaluation substrate using a vacuum press under the conditions of 100 hPa vacuum, 100°C, 0.35 MPa, and 3 minutes. After that, the evaluation substrate with the dry film attached was heated in a 150°C oven for 1 hour to heat-cur the various curable resin layers. After heat curing, the release PET 1-TR3 on the transparent curable resin layer side was peeled off, and the uniformity of the blackness was evaluated.

[0155] The entire surface of the dry film, which had been pressed and cured onto the evaluation substrate, was observed using transmitted light with a digital microscope VHX-7000 (manufactured by KEYENCE). Cases where no unevenness in black was observed across the entire surface of the dry film and the blackness could be evaluated as uniform were categorized as (A), cases where no large unevenness in black was observed but transmitted light was visible near the copper pattern were categorized as (B), and cases where large unevenness in black was observed across the entire surface of the dry film were categorized as (C).

[0156] Table 2 shows the composition of the dry films for each example and comparative example, as well as the various evaluation results.

[0157] [Table 2]

[0158] In Examples 1-4, the L*a*b* values ​​were in the ranges of L*: 0-20, a*: -2-2, and b*: -3-3. On the other hand, while the L* values ​​in Comparative Examples 1 and 2 were all in the range of 0-20, the a* values ​​were not in the range of -2-2, and the b* values ​​were not in the range of -3-3. Therefore, it was found that the dry films of each example had a higher blackness than the dry films of each comparative example.

[0159] The evaluation of the uniformity of blackness after implementation was as follows. Both Examples 1 and 3 received an A rating, which was higher than the B ratings for Examples 2 and 4 and the C ratings for Comparative Examples 1 and 2. This is thought to be due to the following reasons: In the dry films that received an A rating, the storage modulus of the transparent curable resin layer was sufficiently larger than that of the black curable resin layer. As a result, when the black curable resin layer was pressed into the copper pattern, the deformation of the transparent curable resin layer in areas without a copper pattern was small, and the film thickness of the black curable resin layer that followed the shape between the transparent curable resin layer and the substrate was kept uniform. Another reason is that the storage modulus of the black curable resin layer in the dry films that received an A rating was within an appropriate range and had appropriate fluidity, which suppressed localized flow and allowed for the maintenance of a uniform film thickness. [Industrial applicability]

[0160] The dry film according to the present invention can be used, for example, as a sheet to seal a substrate on which multiple light-emitting elements are arranged. [Explanation of Symbols]

[0161] 1, 1a, 1b... Dry film, 2... Substrate with element, 5... Light-emitting electronic component, 10... Black curable resin layer, 11... Transparent curable resin layer, 13, 14... Protective sheet, 20... Substrate, 21, 22, 23... Light-emitting element, 30... Black resin layer, 31... Transparent resin layer.

Claims

1. A dry film for pressing onto the surface of an element-equipped substrate on which a plurality of light-emitting elements are arranged, wherein the plurality of light-emitting elements are arranged on the substrate, The present invention includes at least a black curable resin layer for shielding light between the plurality of light-emitting elements, A dry film characterized in that, when the black curable resin layer is in an uncured state, the L*a*b* values ​​obtained by measurement on the surface opposite to the surface in contact with the substrate with the element are L*: 0 to 20, a*: -2 to 2, and b*: -3 to 3.

2. The dry film according to claim 1, characterized in that the total light transmittance is 0 to 30% when the black curable resin layer is cured.

3. The dry film according to claim 1, characterized in that the black curable resin layer contains a black pigment and a dye.

4. The dry film according to claim 1, characterized in that the mass ratio of the black pigment to the dye is 100:1 to 1:

1.

5. The dry film according to claim 1, characterized in that the absorption peak of the dye measured by an ultraviolet-visible spectrophotometer is located at 500 to 650 nm.

6. The storage modulus of the aforementioned black curable resin layer at 100°C is 1.0 × 10⁻⁶. ５ The dry film according to claim 1, characterized in that it is Pa or less.

7. The dry film according to claim 1, characterized in that the black curable resin layer contains an epoxy resin.

8. The dry film according to claim 1, characterized in that the black curable resin layer contains an elastomer.

9. The dry film according to claim 1, further comprising a transparent curable resin layer having higher light transmittance than the black curable resin layer.

10. The storage modulus of the transparent curable resin layer at 100°C is 1.0 × 10⁻⁶. ３ ~1.0 x 10 ７ The dry film according to claim 9, characterized in that it is Pa.

11. The dry film according to claim 9, characterized in that the transparent curable resin layer contains a phenoxy resin.

12. A substrate with multiple light-emitting elements arranged on the substrate, A cured dry film according to any one of claims 1 to 11, which is in a state of being pressed against the surface on which the plurality of light-emitting elements are arranged on the substrate with the element, Equipped with, A light-emitting electronic component characterized in that, when the black curable resin layer is in an uncured state, the L*a*b* values ​​obtained by measurement on the surface opposite to the surface in contact with the substrate with the element are L*: 0 to 20, a*: -2 to 2, and b*: -3 to 3.

13. The light-emitting electronic component according to claim 12, characterized in that the cured dry film further comprises a transparent resin layer having higher light transmittance than the black resin layer, on the side of the cured black resin layer that is further away from the substrate than the black resin layer after curing of the black curable resin layer.

14. The light-emitting electronic component according to claim 13, characterized in that the thickness of the transparent resin layer is 0.1 to 5.0 times the height of the plurality of light-emitting elements.

15. A step of placing the dry film according to any one of claims 1 to 11 on the surface of an element-equipped substrate on which a plurality of light-emitting elements are arranged, A step of filling at least a portion of the black curable resin between the plurality of light-emitting elements, A method for manufacturing a light-emitting electronic component, comprising the step of curing all curable resin layers, including the aforementioned black curable resin.

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