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

Abstract

The present invention provides a dry film capable of suppressing brightness loss in a display when a light-emitting element is lit, 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 on which a plurality of light-emitting elements are arranged on an element-equipped substrate, wherein the dry film includes at least a colored curable resin layer for shielding light between the plurality of light-emitting elements, and the relationship shown below (Equation 1) holds between the average absorbance values ​​between wavelengths of 360 to 830 nm, the average absorbance values ​​between wavelengths of 450 to 480 nm, the average absorbance values ​​between wavelengths of 510 to 540 nm, and the average absorbance values ​​between wavelengths of 620 to 650 nm of the ultraviolet-visible absorption spectrum obtained by measuring the colored resin layer after curing. JPEG2026074487000014.jpg20170

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 project] [Problems that the invention aims to solve]

[0008] However, there is still room for improvement in the above-mentioned conventional technology 2. This is to reduce the brightness loss of the display. The market demands displays with higher brightness.

[0009] The present inventors have made this invention to meet such market demands, and the objective is to suppress the brightness loss of a display when the light-emitting element is lit. [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 colored curable resin layer for shielding light between the plurality of light-emitting elements, The following relationship (Equation 1) holds between the average absorbance values ​​in the ultraviolet-visible absorption spectrum obtained by measuring the colored resin layer after curing, between wavelengths of 360 to 830 nm, between wavelengths of 450 to 480 nm, between wavelengths of 510 to 540 nm, and between wavelengths of 620 to 650 nm.

number

Equation

Number

Advantages of the Invention

[0011] According to the present invention, it is possible to suppress the brightness loss of a display when the light-emitting element is lit. [Brief explanation of the drawing]

[0012] [Figure 1] Figure 1 shows a cross-sectional view of a dry film comprising a colored curable resin layer and a transparent curable resin layer as curable resin layers. [Figure 2] Figure 2 shows a cross-sectional view identical to Figure 1 of a dry film having only a colored curable resin layer as the curable resin layer. [Figure 3] Figure 3 shows a cross-sectional view identical to that of Figure 1, when the dry film shown in Figure 1 is positioned so that its colored curable resin layer is in contact with the top surface of the light-emitting element on the substrate with the element. [Figure 4] 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 attached, progressing from the stage in Figure 3 to the point where the colored curable resin layer and the transparent curable resin layer shown in Figure 1 are embedded between the light-emitting elements. [Figure 5] Figure 5 shows a cross-sectional view identical to Figure 1, showing the state after further progress from the stage in Figure 4, where the protective sheet on the transparent curable resin layer has been peeled off and the curing process has been performed. [Modes 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 colored 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 includes at least a colored 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 colored curable resin layer 10. In the dry film 1a, the colored curable resin layer 10 and the transparent curable resin layer 11 are laminated together.

[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 colored curable resin layer 10 and the transparent curable resin layer 11 remain uncured until the curing process, described later, is performed. That is, the colored curable resin layer 10 and the transparent curable resin layer 11 are cured by the curing process to become the colored 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 colored curable resin layer 10 and the transparent curable resin layer 11 for ease of handling.

[0019] (2) Colored curable resin layer The colored curable resin layer 10, after curing, becomes a colored 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 colored 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] [Light transmittance and absorbance] In this application, "light transmittance" refers to light transmittance measured by various known methods. For example, as described below, it may be the light transmittance for all visible light wavelengths (hereinafter also referred to as "total light transmittance"), or it may be the light transmittance for a specific wavelength.

[0021] The total light transmittance of the colored curable resin layer 10 and the transparent curable resin layer 11 (i.e., the colored resin layer 30 and the transparent resin layer 31) in their cured state is obtained as follows. For example, in the case of the total light transmittance of the colored 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 in the entire visible light wavelength range (for example, wavelength 360 to 830 nm) using a haze meter (for example, NDH5000 manufactured by Nippon Denshoku Industries Ltd.). Next, a laminated sheet is prepared by laminating the cured colored 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 colored curable resin layer 10 in its cured state.

[0022] Furthermore, the total light transmittance of the transparent curable resin layer 11 in its cured state can be obtained by the same method used to determine the total light transmittance of the colored curable resin layer 10.

[0023] The average value of the absorbance of visible light in the cured state of the colored curable resin layer 10 (i.e., the colored resin layer 30) is obtained as follows. First, in accordance with JIS K0115, the absorbance of the substrate sheet, for example, the protective sheet 13 described later, is measured using an ultraviolet-visible spectrophotometer [manufactured by JASCO Corporation, model: V-770DS] or the like in the entire wavelength range of visible light (for example, wavelength 360 to 830 nm) and used as a reference.

[0024] Next, a laminated sheet is prepared by laminating a cured colored curable resin layer 10 onto a protective sheet 13, and the absorbance of the laminated sheet is measured in the same manner. Using the above reference, the absorbance value of the laminated sheet, excluding the effect of the protective sheet 13, is calculated from the obtained absorbance value of the laminated sheet. This value is taken as the absorbance of the colored curable resin layer 10 in its cured state.

[0025] The colored curable resin layer 10 is prepared such that, in its cured state, the following relationship (Equation 1) holds between the average absorbance of the ultraviolet-visible absorption spectrum between wavelengths of 360 to 830 nm, the average absorbance between wavelengths of 450 to 480 nm, the average absorbance between wavelengths of 510 to 540 nm, and the average absorbance between wavelengths of 620 to 650 nm.

number

[0026] The light-emitting elements 21, 22, and 23 emit, for example, blue, green, and red light. For these lights, peaks in emission intensity are observed between wavelengths of 450-480 nm, 510-540 nm, and 620-650 nm, respectively.

[0027] Some of the light from the light-emitting elements 21, 22, and 23 may reach the viewer's eye after passing through the colored resin layer 30, which may remain slightly on the top surface of the light-emitting elements 21, 22, and 23 and / or the colored resin layer 30, which may be located on the upper sides of the light-emitting elements 21, 22, and 23. When light passes through the colored resin layer 30, some of the light is absorbed by the colored resin layer 30. Therefore, if the absorbance of the colored resin layer 30 is high, the amount of light reaching the viewer decreases, resulting in a loss of brightness in the display.

[0028] The average absorbance of the colored curable resin layer 10 in its cured state, measured across the entire visible light wavelength range of 360-830 nm, is greater than the average absorbance across the wavelengths of 450-480 nm, 510-540 nm, and 620-650 nm. The value obtained by dividing the former by the latter is 1.25 or greater, preferably between 1.25 and 10. This also means that the average of the average light transmittances of the colored curable resin layer 10 after curing across the wavelengths of 450-480 nm, 510-540 nm, and 620-650 nm is greater than the average light transmittance of the entire visible light spectrum.

[0029] Here, the wavelength ranges of 450-480 nm, 510-540 nm, and 620-650 nm almost coincide with the wavelength ranges in which the emission intensity peaks of the light-emitting elements 21, 22, and 23 are observed. Therefore, in the cured state, the colored curable resin layer 10 selectively transmits only the light from the light-emitting elements 21, 22, and 23, thereby suppressing the brightness loss of the display.

[0030] Preferably, the colored curable resin layer 10 is prepared such that the following relationship (Equation 2) holds between the minimum of the average absorbance values ​​obtained by measuring the UV-Vis absorption spectrum of the colored curable resin layer 10 in the cured state at wavelengths of 410 to 440 nm, the average absorbance values ​​at wavelengths of 560 to 590 nm, and the average absorbance values ​​at wavelengths of 700 to 730 nm, and the average absorbance value at wavelengths of 360 to 830 nm.

number

[0031] In other words, preferably, the average absorbance values ​​obtained by measuring the colored curable resin layer 10 in a cured state, such as the average absorbance values ​​between wavelengths of 410-440 nm, 560-590 nm, and 700-730 nm in the ultraviolet-visible absorption spectrum, are all higher than the average absorbance value for all visible light.

[0032] The wavelength ranges of 410-440 nm, 560-590 nm, and 700-730 nm do not coincide with the wavelength ranges in which the light-emitting elements 21, 22, and 23 exhibit peak emission intensity. However, natural light contains these visible light wavelengths. Furthermore, viewers can perceive light in these wavelength ranges as color. When the light-emitting elements 21, 22, and 23 are not emitting light, these visible light wavelengths can be observed by the viewer as reflected light from the top and sides of the light-emitting elements. This leads to a decrease in the blackness of the display when the elements are not emitting light. The colored curable resin layer 10 in its cured state absorbs these visible light wavelengths, contributing to an increase in the blackness of the display when the elements are not emitting light.

[0033] The absorbance of the colored curable resin layer 10 in its cured state can be adjusted primarily by the amount of dyes and pigments used in the formulation, as described later.

[0034] The total light transmittance of the colored curable resin layer 10 in its cured state is adjusted to be between 0 and 80%. When the total light transmittance of the colored curable resin layer 10 in its cured state is relatively high, near the upper limit, the cured dry film 1a exhibits the light transmission selectivity described above while remaining gray in color.

[0035] The total light transmittance of the colored curable resin layer 10 in its cured state is preferably adjusted to 0-30%. More preferably, it is adjusted to 1-10%, even more preferably 1.5-5%, and particularly preferably 2-5%. By setting the total light transmittance to 30% or less, and even lower than 30%, the effect of suppressing light interference between the light-emitting elements 21, 22, and 23, and the blackness of the light-emitting elements 21, 22, and 23 when they are not emitting light can be enhanced. For example, by setting the total light transmittance to 5% or less, a higher level of blackness can be achieved when the display is not emitting light. Furthermore, by setting the lower limit of the total light transmittance to 1% or more, even if the colored curable resin layer 10 remains on the top surface of multiple light-emitting elements 21, 22, and 23 during the filling and curing process, the light-shielding performance between the light-emitting elements 21, 22, and 23 is maintained without hindering the light emission of the light-emitting elements 21, 22, and 23 toward the viewer. The total light transmittance of the colored curable resin layer 10 in its cured state can be changed primarily by the amount of dyes and / or pigments used, as described later. Furthermore, this total light transmittance can also be changed by the thickness of the colored curable resin layer 10 and the type of resin composition.

[0036] [Storage modulus] The storage modulus of the colored curable resin layer 10 in its uncured state is preferably 1.0 × 10⁻⁶ at 100°C. 5 It is less than or equal to Pa, and more preferably 1.0 × 10⁻⁶ 1 ~1.0×10 5 Pa is more preferably 1.0 × 10 2 ~5.0×10 4 It is Pa.

[0037] Because the storage modulus of the colored curable resin layer 10 is below a preferred upper limit at 100°C, the colored 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.

[0038] Since the storage elastic modulus of the colored curable resin layer 10 is at least the preferable lower limit value at 100°C, it is possible to prevent uneven pressure during thermocompression bonding of the colored curable resin layer 10. Even when the colored curable resin layer 10 remains on the top surfaces of the plurality of light-emitting elements 21, 22, 23 in the filling and curing process due to differences in the height and inclination of the light-emitting elements, a uniform coloring degree can be maintained. Also, it is possible to prevent the resin from flowing out beyond a predetermined range and ensure the film thickness after pressure bonding.

[0039] The storage elastic modulus of the colored curable resin layer 10 in the uncured state is preferably 5.0×10 5 Pa or less at 150°C, more preferably 5.0×10 2 ~5.0×10 5 Pa, and even more preferably 1.0×10 1 ~1.0×10 4 Pa.

[0040] Since the storage elastic modulus of the colored curable resin layer 10 is at most the preferable upper limit value at 150°C, cracks due to curing shrinkage are less likely to occur during thermosetting.

[0041] Since the storage elastic modulus of the colored curable resin layer 10 is at least the preferable lower limit value at 150°C, the flow during thermosetting can be suppressed, and appearance defects after curing such as repelling phenomena are suppressed.

[0042] [Curable resin composition] (Colorant) The colored curable resin layer 10 preferably contains a dye (including a mixture of multiple dyes) as a coloring agent to exhibit the function of selectively transmitting light with wavelengths of 450-480 nm, 510-540 nm, and 620-650 nm after curing. Furthermore, the curable resin layer 10 may also contain a pigment as a coloring agent for the purpose of enhancing light shielding and blackness. The content of the coloring agent is preferably 0.05 to 15 parts by mass, more preferably 1 to 10 parts by mass, and even more preferably 1.25 to 7.5 parts by mass, per 100 parts by mass of the total resin solids of the colored curable resin layer 10. If the content is above the lower limit, sufficient light shielding between the light-emitting elements can be obtained. If the content is below the upper limit, the thixotropy of the colored curable resin layer 10 can be reduced, and the fluidity of the colored curable resin layer 10 during thermocompression bonding can be increased. As a result, the colored curable resin layer 10 can sufficiently fill the spaces between the multiple light-emitting elements 21, 22, and 23 of the element-equipped substrate 2.

[0043] ·dye The dyes that can be used to achieve the above objectives may be either inorganic dyes and / or organic dyes. As the dye for the colored curable resin layer 10, 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 the dyes, dyes with a bluish tint, such as azine dyes and aniline dyes, are preferred.

[0044] The dye used may be a single type or a combination of multiple dyes. In order to increase the absorbance at wavelengths of 410-440 nm, 560-590 nm, and 700-730 nm, it is particularly preferable to use a combination of multiple dyes that exhibit absorbance peaks in or near these wavelength ranges. Suitable examples of such dyes include, for example, Hayashibara Corporation's product numbers: NK-10396 (absorbance peak: wavelength 425 nm), NK-4697 (absorbance peak: wavelength 588 nm), and NK-3291 (absorbance peak: wavelength 746 nm). The dye content is preferably 0.01 to 15 parts by mass, more preferably 0.1 to 10 parts by mass, and even more preferably 0.8 to 7.5 parts by mass, per 100 parts by mass of the total resin solids of the colored curable resin layer 10.

[0045] Pigments As described above, in addition to dyes, pigments may be used as appropriate as colorants. Preferably, the pigments may contain carbon black, titanium oxide (titanium black), iron oxide (black iron oxide), etc., and more preferably carbon black. As 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 may 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.

[0046] Pigments with high blackness can be used in combination with dyes to enhance light shielding between light-emitting elements in light-emitting electronic components. They can also be used to neutralize color by combining them with pigments of complementary colors to the dye's color. For example, a slightly yellowish carbon black can be combined with the aforementioned bluish dye. In this case, it is preferable to use a dye whose absorption peak, measured by an ultraviolet-visible spectrophotometer, is between 510 and 650 nm, as this neutralizes the yellowish tint of the carbon black and increases its blackness.

[0047] 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 colored curable resin layer 10 contains a modified elastomer having functional groups that can react with epoxy resin, the dispersibility is further enhanced by the interaction between the surface functional groups of the gas black and the functional groups of the modified elastomer having functional groups that can react with epoxy resin. Therefore, by adding a small amount of gas black in addition to the dye, good light-shielding properties and coating stability can be ensured. As an example of such gas black, Special Black #4 manufactured by ORION ENGINEERED CARBONS is a suitable example. When a pigment is used in addition to the dye, the mass ratio of the two (dye:pigment) is preferably 100:1 to 1:1, more preferably 20:1 to 2:1, and even more preferably 10:1 to 3:1.

[0048] (curable resin) The colored 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.

[0049] If the colored 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.

[0050] (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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] Among the epoxy resins mentioned above, polyfunctional epoxy resins are preferred as the epoxy resin used in the colored 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, improving the stability of the performance of the cured epoxy resin composition for long-term use and increasing the crosslinking density. In addition, the heat resistance of the cured product is also improved.

[0055] Specific examples of novolac-type epoxy resins include, for example, "YX7700" from Mitsubishi Chemical Corporation, "NC7000L," "XD1000," and "EOCN-1020" from Nippon Kayaku Co., Ltd., "ESN485" from Nippon Steel Chemical & Material Co., Ltd., and "N-660," "N-690," "N-695," and "HP-7200H" from DIC Corporation.

[0056] The amount of polyfunctional epoxy resin blended in the colored 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 colored 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 colored curable resin layer 10 can be ensured.

[0057] The colored curable resin layer 10 preferably does not contain high molecular weight epoxy resin. This makes it easier to ensure sufficient fluidity of the colored curable resin layer 10 during heat bonding. When the colored 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 colored curable resin layer 10.

[0058] From the viewpoint of ensuring sufficient fluidity during thermocompression bonding, the colored 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 colored 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 colored curable resin layer 10.

[0059] The total amount of epoxy resin in the colored 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 colored curable resin layer 10. Within this range, it becomes easier to control the storage modulus of the colored curable resin layer 10 and ensure appropriate fluidity during heat bonding. Furthermore, if it is above the lower limit, the heat resistance of the colored curable resin layer 10 after curing can be improved.

[0060] (Elastomer) The colored 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 colored curable resin layer 10, i.e., control its fluidity. This prevents uneven pressure distribution during the thermal bonding of the colored curable resin layer 10, and even if the colored 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.

[0061] 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 colored curable resin layer 10 at around 100°C, and as a result, good adhesion between the colored curable resin layer 10 and the transparent curable resin layer 11 and the element-equipped substrate 2.

[0062] 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 colored 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 colored curable resin layer 10 during thermal curing can be controlled more effectively.

[0063] In particular, when the colored 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 colored 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, resulting in good dispersibility for incorporating carbon black into the colored curable resin layer 10.

[0064] 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.

[0065] In other words, if the colored 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.

[0066] 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.

[0067] The amount of elastomer in the colored curable resin layer 10 is preferably 0.01 to 90 parts by mass, more preferably 1 to 80 parts by mass, and even more preferably 5 to 65 parts by mass, based on 100 parts by mass of the total resin solids of the colored curable resin layer 10. Within this range, it becomes easier to control the storage modulus of the colored curable resin layer 10 and ensure appropriate fluidity of the colored curable resin layer 10 during thermocompression bonding. By ensuring this fluidity, it is possible to prevent pressure unevenness during thermocompression bonding of the colored curable resin layer 10, and even if the colored 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 film thickness distribution when coating and forming a film with the epoxy resin composition can be narrowed.

[0068] (Hardening agent) If the colored 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.

[0069] (curing catalyst) If the colored 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 cationic polymerization initiators, anionic polymerization initiators, and radical polymerization initiators. Among these, cationic polymerization initiators are preferred because they do not react easily with colorants during the curing reaction of the epoxy resin composition and do not easily change absorbance or color due to the curing reaction. Cationic polymerization initiators are curing catalysts such as sulfonium salts and iodonium salts, and sulfonium salt curing catalysts are preferred. Among sulfonium salt curing catalysts, those having a phosphorus hexafluoride anion as the anionic component are particularly preferred. Examples of anionic polymerization initiators include imidazole, tertiary amine, and phosphorus compound curing catalysts. Examples of radical polymerization initiators include curing catalysts such as organic peroxides. The amount of curing catalyst added is preferably 0.01 to 5 parts by mass, more preferably 0.05 to 4 parts by mass, and even more preferably 0.1 to 3.5 parts by mass, per 100 parts by mass of the total resin solids of the colored curable resin layer 10. Within this range, the curing of the colored curable resin layer 10 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.

[0070] (Other ingredients) The colored curable resin layer 10 may contain inorganic fillers to improve flame retardancy and heat resistance, and to adjust the refractive index. The colored curable resin layer 10 may also, if necessary, contain resins other than epoxy resin and elastomer, thickeners, defoamers and / or adhesion-enhancing agents such as leveling agents and coupling agents, and flame retardants.

[0071] [film thickness] The thickness of the colored 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.

[0072] (3)Transparent curable resin layer The transparent curable resin layer 11 is a layer that, during bonding, sufficiently presses the colored 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 colored resin layer 30, and therefore blocks almost no light from the light-emitting elements compared to the colored resin layer 30.

[0073] [Total light transmittance] The total light transmittance of the transparent curable resin layer 11 in its cured state is higher than that of the colored 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%, more preferably 60-99%, and even more preferably 70-99%. 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 is equivalent to that of the colored resin layer 30. The relationship between the transparent curable resin layer 11 and the colored curable resin layer 10 on the light transmittance of the dry film 1a will be described in detail below.

[0074] [Storage modulus] The storage modulus of the transparent curable resin layer 11 in its uncured state is preferably greater than that of the colored 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 colored curable resin layer 10.

[0075] The storage modulus of the transparent curable resin layer 11 is preferably greater than that of the colored 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 colored 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 colored curable resin layer 10 across the entire temperature range of 100 to 150°C.

[0076] 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 more like 5.0 × 10 3 ~6.0×10 5 It is Pa.

[0077] 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 colored curable resin layer 10 when it is pressed onto the substrate 2 with the element. In addition, the spaces between the multiple light-emitting elements 21, 22, and 23 can be sufficiently filled.

[0078] 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, and the colored curable resin layer 10 is uniformly pressed in, thereby maintaining a uniform film thickness of the colored curable resin layer 10. As a result, even if the colored curable resin layer 10 remains on the top surfaces of multiple light-emitting elements 21, 22, and 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.

[0079] 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.

[0080] 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.

[0081] By ensuring that the storage modulus of the transparent curable resin layer 11 is above a preferred lower limit at 150°C, the flow and generation of bubbles during the thermal curing of the transparent curable resin layer 11 can be suppressed.

[0082] The storage modulus of the transparent curable resin layer 11 is preferably 10 to 1,000 times, more preferably 30 to 500 times, the storage modulus of the colored curable resin layer 10 at 100°C. The storage modulus of the transparent curable resin layer 11 is preferably 5 to 10,000 times, more preferably 10 to 1,000 times, the storage modulus of the colored curable resin layer 10 at 150°C. If the storage modulus of the transparent curable resin layer 11 is greater than that of the colored 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 colored curable resin layer 10 across the entire temperature range of 100 to 150°C.

[0083] [Curable resin composition] The transparent curable resin layer 11 contains a curable resin composition. Similar to the colored 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.

[0084] (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 colored curable resin layer 10. From the viewpoint of imparting an appropriate viscosity during bonding to the transparent curable resin layer 11, 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 high-boiling-point solvents 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.

[0085] 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. For this reason, the storage modulus of the transparent curable resin layer 11 in the 100 to 150°C range can be adjusted to a preferred range. The high molecular weight epoxy resin is preferably a phenoxy resin due to its good compatibility with other epoxy resins.

[0086] Phenoxy resin has a relatively large 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 and does not impair the heat resistance or reliability of the cured product's performance for long-term use. From the viewpoint of ensuring a storage modulus that presses the colored 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.

[0087] Specific examples of phenoxy resins include, for example, "1256," "YX7200," "YX8100," "YX7180," and "jER(registered trademark) YX7200B35" from Mitsubishi Chemical Corporation, "YP-50," "YP-50S," and "YP-70" from Nippon Steel Chemical & Material Corporation, and "N-690," "H-157," and "EXA-192" from DIC Corporation.

[0088] 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.

[0089] 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.

[0090] 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.

[0091] 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 Co., Ltd., "ESN485" from Nippon Steel Chemical & Material Co., Ltd., and "N-660," "N-690," "N-695," and "HP-7200H" from DIC Corporation.

[0092] 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.

[0093] 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.

[0094] 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 colored 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 value is above the lower limit, the heat resistance in the cured state is improved.

[0095] (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 for the colored curable resin layer 10. Among these, NBR is preferred for the following reasons: NBR has good compatibility with epoxy resin. It also increases 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 colored curable resin layer 10. The preferred weight-average molecular weight of the elastomer is the same as that of the colored curable resin layer 10.

[0096] 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.

[0097] Functional groups that can react with epoxy groups include those of the same type as those used in the colored 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.

[0098] 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 colored curable resin layer 10. Two or more modified elastomers having functional groups that can react with epoxy groups may be used in combination.

[0099] 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 colored 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 colored 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.

[0100] (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 colored curable resin layer 10. Two or more of these other curing agents may be used in combination.

[0101] (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 colored curable resin layer 10, and preferred embodiments are also similar.

[0102] The amount of curing catalyst added is preferably 0.01 to 5 parts by mass, more preferably 0.05 to 4 parts by mass, and even more preferably 0.1 to 3 parts by mass, per 100 parts by mass of the total resin solids of the transparent curable resin layer 11. Within this range, curing can proceed sufficiently, and the pot life of the dry film 1a can be ensured. Two or more types of curing catalysts may be used in combination.

[0103] (Other ingredients) The transparent curable resin layer 11 may contain pigments or dyes to suppress uneven luminescence and color unevenness.

[0104] If the transparent curable resin layer 11 contains carbon black, the amount of carbon black is preferably less than 5 parts by mass, more preferably 1 part by mass or less, and even more preferably 0.1 parts by mass or less, 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, and flame retardants.

[0105] [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.

[0106] (4) 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.

[0107] 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.

[0108] 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.

[0109] (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 colored curable resin layer as the curable resin layer.

[0110] (2) Curable resin layer constituting the dry film Dry film 1b comprises only a colored curable resin layer 10 as the curable resin layer, and does not have a transparent curable resin layer 11. If a thick colored resin layer 30 is present 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 colored 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 colored curable resin layer 10, as well as the protective sheet 13, are the same as those of dry film 1a, so redundant explanations are omitted. In the manufacturing process of dry film 1b, the process of laminating the transparent curable resin layer 11 is not required, so the effort and cost of the manufacturing process can be further reduced.

[0111] 2. Method for manufacturing dry film To obtain the dry film 1a, first, a protective sheet 13 is coated with a coating solution of a curable resin composition for the colored curable resin layer 10 and dried (A), and a protective sheet 14 is coated with a coating solution of a curable resin composition for the transparent curable resin layer 11 and dried (B).

[0112] Subsequently, by laminating (A) and (B) above so that the transparent curable resin layer 11 and the colored curable resin layer 10 are in contact, a dry film 1a is obtained in which the colored curable resin layer 10 and the transparent curable resin layer 11 are sequentially laminated between two protective sheets 13 and 14.

[0113] The coating liquid of the curable resin composition for the colored 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.

[0114] 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.

[0115] 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 colored 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, it is possible to prevent the trapping of air bubbles between the colored curable resin layer 10 and the transparent curable resin layer 11, and to prevent the formation of wrinkles on each layer 10 and 11. Lamination can be carried out using, for example, a roll laminator, a press, a vacuum press, etc.

[0116] To obtain the dry film 1b, first, a coating liquid of the curable resin composition for the colored 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 colored curable resin layer 10, and then the coating liquid is dried. This results in a dry film 1b having protective sheets 13 and 14 on both sides of the colored curable resin layer 10.

[0117] 3. Circuit board with components Figure 3 shows a cross-sectional view identical to that of Figure 1, when the dry film shown in Figure 1 is positioned so that its colored curable resin layer is in contact with the top surface of the light-emitting element on the substrate with the element.

[0118] 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.

[0119] 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.

[0120] 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.

[0121] 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 colored curable resin layer and the transparent curable resin layer of 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.

[0122] 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, 23 are arranged on a substrate 20, and a cured body 3 of a 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, 23 are arranged. The following relationship (Equation 1) holds between the average absorbance between wavelengths of 360 to 830 nm, the average absorbance between wavelengths of 450 to 480 nm, the average absorbance between wavelengths of 510 to 540 nm, and the average absorbance between wavelengths of 620 to 650 nm of the ultraviolet-visible absorption spectrum obtained by measuring the colored resin layer 30 after the curing of the colored curable resin layer 10.

number

[0123] The average absorbance across all visible light wavelengths from 360 to 830 nm is greater than the average absorbance across wavelengths from 450 to 480 nm, 510 to 540 nm, and 620 to 650 nm, and the value obtained by dividing the former by the latter is 1.25 or greater, preferably between 1.25 and 10. In other words, the average of the average visible light transmittances of the colored curable resin layer 10 after curing across wavelengths from 450 to 480 nm, 510 to 540 nm, and 620 to 650 nm is higher than the average visible light transmittance.

[0124] The light-emitting elements 21, 22, and 23 have emission intensity peaks at wavelengths that closely coincide with 450-480 nm, 510-540 nm, and / or 620-650 nm. Therefore, the colored resin layer 30 can selectively transmit light emitted by the light-emitting elements 21, 22, and 23.

[0125] A small amount of the colored resin layer 30 may remain on the top surface of the light-emitting elements 21, 22, and 23. Therefore, some of the light from the light-emitting elements 21, 22, and 23 may pass through the colored resin layer 30 before reaching the viewer's eyes. This light transmission may also occur through the colored resin layer 30 located on the upper sides of the light-emitting elements 21, 22, and 23. However, since the colored resin layer 30 does not easily block the light from the light-emitting elements 21, 22, and 23, a decrease in display brightness can be suppressed.

[0126] As described above, by mainly changing the proportions of dyes and pigments, the dry films 1a and 1b can be given the effect of suppressing the decrease in brightness of this display. At the same time, the dry films 1a and 1b can also be given the effect of increasing blackness.

[0127] The cured bodies 3 of the dry films 1a and 1b each include a colored resin layer 30 that shields light from the multiple light-emitting elements 21, 22, and 23 from the side in contact with the substrate 2 with the elements, 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 colored resin layer 30, which has higher light transmittance than the colored resin layer 30. The colored resin layer 30 and the transparent resin layer 31 are cured layers obtained by heat curing or the like of the colored 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.

[0128] The thickness of the colored 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, 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, 23.

[0129] (Brightness transmittance) In this application, "luminance transmittance" refers to the transmittance calculated from the luminance of the light-emitting elements 21, 22, and 23 on the element-mounted substrate 2 before and after the dry film 1 is pressed onto it. Specifically, the luminance transmittance is calculated by measuring the luminance of the light-emitting elements 21, 22, and 23 on the element-mounted substrate 2 when they are lit (hereinafter also referred to as pre-mounting luminance) and the luminance of the light-emitting electronic component 5 when it is lit (hereinafter also referred to as post-mounting luminance). Then, each measured value is substituted into the following (Equation 2) to calculate the luminance transmittance. That is, it is calculated by dividing the post-mounting luminance by the pre-mounting luminance. The luminance transmittance is preferably 70% or more, and more preferably 75 to 90%. Luminance transmittance (%) = (Luminance after implementation / Luminance before implementation) × 100 ... (Equation 3)

[0130] The method for manufacturing a light-emitting electronic component according to this embodiment includes the steps of: placing the colored 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 to press it down (hereinafter referred to as the placement step); continuing to press it down to fill at least a portion of the colored 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 colored 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 colored 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.

[0131] (i) Placement process In the manufacturing method of this embodiment, first, the protective sheet 13 is peeled off to expose the color-curable resin layer 10, and as shown in Figure 3, the color-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.

[0132] Before bonding, the thickness of the colored 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.

[0133] If the thickness of the colored 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 colored 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 colored 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 colored curable resin layer 10 is 30% or more of the height of the light-emitting elements 21, 22, and 23, the colored curable resin layer 10 with light-shielding function can be appropriately filled between the light-emitting elements 21, 22, and 23.

[0134] If the thickness of the colored curable resin layer 10 is 95% or less of the height of the light-emitting elements 21, 22, and 23, leakage of the colored 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 be obstructed from reaching the viewer. If the thickness of the colored 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 colored 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 colored curable resin layer 10 is 75% or less of the height of the light-emitting elements 21, 22, and 23, the colored curable resin layer 10 with light-shielding function can be appropriately filled between the light-emitting elements 21, 22, and 23.

[0135] 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.

[0136] 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 the fluidity of the layer 11 is suppressed, it is possible to suppress the flow of the transparent curable resin layer 11 together with the colored 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 colored curable resin layer 10 into it.

[0137] The total thickness of the colored curable resin layer 10 and the transparent curable resin layer 11 before lamination is preferably 110 to 550% of the height of the light-emitting elements 21, 22, and 23. If the total 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 total 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.

[0138] The ratio of the thickness of the colored curable resin layer 10 to the total thickness of the transparent curable resin layer 11 and the colored curable resin layer 10 before bonding 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 colored curable resin layer 10 remains on the light-emitting elements 21, 22, and 23 during bonding, and the brightness can be sufficiently improved.

[0139] In the case of a dry film 1b comprising only a colored curable resin layer 10 as the curable resin layer, the thickness of the colored 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 colored 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 colored curable resin layer 10 is filled between the multiple light-emitting elements 21, 22, and 23. If the storage modulus of the colored curable resin layer 10 is relatively low and the fluidity of the layer 10 is ensured, the colored 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.

[0140] 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 colored 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 colored curable resin layer 10, suppressing the occurrence of unevenness and crack-like defects.

[0141] 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 colored 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.

[0142] (iii) Curing process After pressing, as shown in Figure 5, the protective sheet 14 is peeled off and then heat-cured to form the colored curable resin layer 10 and the transparent curable resin layer 11 of the dry film 1 into a colored resin layer 30 (cured layer of colored curable resin layer 10) and a transparent resin layer 31 (cured layer of transparent curable resin layer 11).

[0143] 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 colored 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 colored 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.

[0144] 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 colored curable resin layer 10 and the transparent curable resin layer 11 after curing can be suppressed.

[0145] 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 colored curable resin layer 10 before pressing and the pressing conditions are the same as when using dry film 1a, so a description is omitted.

[0146] As described above, through the processes 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 which the light-emitting elements 21, 22, and 23 are located. In the obtained light-emitting electronic component 5, the colored curable resin layer 10 and / or the transparent curable resin layer 11 harden to become a colored resin layer 30 and / or a transparent resin layer 31. [Examples]

[0147] The present invention will be described in detail below with reference to examples. However, the present invention is not limited to these examples.

[0148] <Raw materials> The details of the raw materials used in each example and comparative example are as follows.

[0149] [Epoxy resin for curable resin layers] EOCN 1020-55: Manufactured by Nippon Kayaku Co., Ltd., o-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.

[0150] [Elastomer] NX775: Manufactured by Zeon Corporation, carboxy-modified nitrile rubber, weight-average molecular weight 208,000.

[0151] [Curing catalyst] • 2PZ-CN: Manufactured by Shikoku Chemicals Co., Ltd., 1-cyanoethyl-2-phenylimidazole. SI110: Benzylmethyl-p-hydroxyphenylsulfonium hexafluorophosphate, manufactured by Sanshin Chemical Industry Co., Ltd.

[0152] [Pigments] • Special Black #4: Gas black manufactured by ORION ENGINEERED CARBONS.

[0153] NK-10396: Manufactured by Hayashibara Corporation, with an absorption peak wavelength of 425 nm in the visible light region of 360-800 nm. • NK-4697: Manufactured by Hayashibara Corporation, with an absorption peak wavelength of 588 nm in the visible light region of 360-800 nm. NK-3291: Manufactured by Hayashibara Corporation, with an absorption peak wavelength of 746 nm in the visible light region of 360-800 nm.

[0154] [solvent] • MEK: Methyl ethyl ketone, manufactured by Junsei Chemical Co., Ltd. PGM: Propylene glycol monomethyl ether, manufactured by Junsei Chemical Co., Ltd.

[0155] <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 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.

[0156] Table 1 shows the raw material compositions of the colored curable resin layer and the transparent curable resin layer used in each example and comparative example. Raw material 1 is the raw material composition of the transparent curable resin layer, and raw materials 2-1 to 2-4 are the raw material compositions of the coating liquid for the colored curable resin layer. In the raw material compositions in Table 1, each value represents parts by mass. Here, 1 part by mass = 1 g.

[0157] [Table 1]

[0158] <Example 1> [Preparation of a transparent curable resin layer] A coating liquid for a transparent curable resin layer (raw material 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 achieve a dry film thickness of 50 μm. After drying at 100°C for 5 minutes, a sheet with a transparent curable resin layer supported on the release PET sheet (hereinafter referred to as the transparent layer sheet) was obtained.

[0159] [Preparation of a colored curable resin layer] A coating solution for a colored 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 achieve a dry film thickness of 50 μm. After drying at 100°C for 5 minutes, a sheet with a colored curable resin layer supported on the release PET sheet (hereinafter referred to as the colored layer sheet) was obtained.

[0160] [Dry film production] The obtained transparent layer laminate and the colored layer laminate were stacked so that the transparent curable resin layer and the colored 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.

[0161] [Evaluation board with components] A substrate with multiple LED light-emitting elements, each measuring 0.1 × 0.2 mm and 65 μm in height, was arranged on an epoxy glass substrate to serve as the evaluation element substrate. This evaluation element substrate was used to measure the pre-mounting brightness in the brightness transmittance calculation described later.

[0162] [Manufacturing of light-emitting electronic components] The release PET from the dry film of each example was peeled off, and the colored curable resin layer was positioned so that it was in contact with the LED light-emitting element on the substrate with the evaluation element. Then, using a vacuum press, the colored curable resin layer and the transparent curable resin layer were filled between the light-emitting elements under the conditions of a vacuum of 100 hPa, 100°C, 0.36 MPa, and for 3 minutes. After filling, the colored curable resin layer and the transparent curable resin layer were heat-cured by heating in an oven at 120°C for 1 hour to obtain a light-emitting electronic component. This light-emitting electronic component was subjected to the measurement of post-mount brightness in terms of brightness transmittance, as described later.

[0163] <Example 2> A dry film was prepared using the same conditions as in Example 1, except that the coating liquid for the colored curable resin layer was changed from raw material 2-1 to raw material 2-2 (see Table 1).

[0164] <Example 3> A dry film was prepared using the same conditions as in Example 1, except that the coating liquid for the colored curable resin layer was changed from raw material 2-1 to raw material 2-3 (see Table 1).

[0165] <Comparative Example 1> A dry film was prepared using the same conditions as in Example 1, except that the coating liquid for the colored curable resin layer was changed from raw material 2-1 to raw material 2-4 (see Table 1).

[0166] <Evaluation Method> [Measurement of Storage Modulus] The storage modulus at 100°C for the colored curable resin layer and the transparent curable resin layer was measured 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, in accordance with JIS K7244. Specifically, a coating solution for the transparent curable resin layer or the colored curable resin layer was applied to the release surface of the release PET using a bar coater to a dry film thickness of 50 μm, and then dried at 100°C for 5 minutes. After drying, the release PET was removed, and the resulting single-layer films of the various curable resin layers were subjected to measurement.

[0167] [Measurement of UV-Vis absorption spectrum] Samples for measuring ultraviolet-visible absorption spectra were measured as follows: A coating solution for a colored curable resin layer was applied to the release surface of release PET 1-E using a bar coater to a dry film thickness of 50 μm. These were dried at 120°C for 5 minutes, and then heated at 150°C for 1 hour to obtain various cured films with release PET attached. Release PET 1-E was also used as a reference for the measurements.

[0168] Measurements were performed using a UV-Vis spectrophotometer (JASCO Corporation, model: V-770DS) at wavelengths of 350-830 nm. UV-Vis absorption spectra were obtained by excluding the influence of release PET 1-E from various cured films with release PET. The values ​​were determined from the obtained UV-Vis absorption spectra as follows. Abs.1: Average absorbance value between wavelengths of 410 and 440 nm • Abs.2: Average absorbance value between wavelengths of 450 and 480 nm Abs.3: Average absorbance value between wavelengths of 510 and 540 nm Abs.4: Average absorbance value between wavelengths of 560 and 590 nm • Abs.5: Average absorbance value between wavelengths of 620 and 650 nm Abs.6: Average absorbance value between wavelengths of 700 and 730 nm • Abs.all: Average absorbance value between wavelengths of 360 and 830 nm. Using these values, we calculated the value on the left side of equation (1) below.

number

[0169] [Calculation of luminance transmittance] The brightness of the light-emitting elements on the evaluation substrate with the dry film attached before lamination and filling was defined as the pre-mounting brightness, and the brightness of the light-emitting elements of the light-emitting electronic component was defined as the post-mounting brightness. For measurement, nine locations were randomly selected from the light-emitting elements on the evaluation substrate. For the nine selected locations, the pre-mounting brightness and post-mounting brightness were measured using a Konica Minolta CA-410 luminance meter. The brightness transmittance was calculated using the following formula (Equation 3). The average value of the brightness transmittance for the nine locations is shown in Table 2 below. A brightness transmittance of 70% or higher was considered a pass, and a value below 70% was considered a fail. Luminance transmittance (%) = (Luminance after implementation / Luminance before implementation) × 100 ... (Equation 3)

[0170] Table 2 shows the results of each evaluation test.

[0171] [Table 2]

[0172] In Examples 1, 2, and 3, the calculated value of the left-hand side of (Equation 1) was 1.25 or greater in all cases. On the other hand, the corresponding value for Comparative Example 1 was 1.00, which is less than or equal to 1.25. The value of Abs.6, which corresponds to Abs.(min) in Comparative Example 1, was 0.942, which was smaller than the Abs.all value of 1.294. On the other hand, the Abs.(min) values ​​for Examples 1, 2, and 3 were 1.302, 1.437, and 1.425, respectively, which were larger than the Abs.all values ​​of 1.285, 1.280, and 1.243.

[0173] Comparative Example 1 had a low luminance transmittance of 66%, which was unacceptable. On the other hand, the corresponding values ​​for Examples 1, 2, and 3 were all high, at 70% or more, and were acceptable. It was found that the dry films of each example could suppress the luminance loss of the display when the light-emitting elements were lit. [Industrial applicability]

[0174] 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]

[0175] 1, 1a, 1b... Dry film, 2... Substrate with element, 5... Light-emitting electronic component, 10... Colored curable resin layer, 11... Transparent curable resin layer, 13, 14... Protective sheet, 20... Substrate, 21, 22, 23... Light-emitting element, 30... Colored 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 colored curable resin layer for shielding light between the plurality of light-emitting elements, A dry film characterized in that the following relationship (Equation 1) holds between the average absorbance between wavelengths of 360 to 830 nm, the average absorbance between wavelengths of 450 to 480 nm, the average absorbance between wavelengths of 510 to 540 nm, and the average absorbance between wavelengths of 620 to 650 nm, obtained by measuring the ultraviolet-visible absorption spectrum of the colored resin layer after curing, the average absorbance between wavelengths of 450 to 480 nm, the average absorbance between wavelengths of 510 to 540 nm, and the average absorbance between wavelengths of 620 to 650 nm. [Math 1] (Abs. all: Average absorbance at wavelengths of 360–830 nm; Abs. 2: Average absorbance between wavelengths of 450–480 nm; Abs. 3: Average absorbance between wavelengths of 510–540 nm; Abs. 5: Average absorbance between wavelengths of 620–650 nm.)

2. The dry film according to claim 1, characterized in that the colored curable resin layer contains a dye.

3. The dry film according to claim 2, characterized in that the colored curable resin layer contains two or more different dyes.

4. The dry film according to claim 2, characterized in that the colored curable resin layer further contains a pigment.

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

6. The dry film according to claim 1, characterized in that the total light transmittance of the colored resin layer is 0 to 80%.

7. The dry film according to claim 6, characterized in that the total light transmittance of the colored resin layer is 0 to 30%.

8. The storage modulus of the aforementioned color-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.

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

10. The dry film according to claim 1, characterized in that the colored curable resin layer contains a cationic polymerization initiator.

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

12. The dry film according to claim 1, characterized in that the following relationship (Equation 2) holds between the minimum of the average absorbance values ​​obtained by measuring the colored resin layer after curing, the average absorbance values ​​between wavelengths of 410 to 440 nm, the average absorbance values ​​between wavelengths of 560 to 590 nm, and the average absorbance values ​​between wavelengths of 700 to 730 nm, and the average absorbance value between wavelengths of 360 to 830 nm. [Math 2] (Abs. (min): The minimum of the average absorbance values ​​between wavelengths of 410-440 nm, 560-590 nm, and 700-730 nm. Abs. all: Average absorbance values ​​between wavelengths of 360-830 nm.)

13. A substrate with multiple light-emitting elements arranged on the substrate, A cured dry film according to any one of claims 1 to 12, 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 the following relationship (Equation 1) holds between the average absorbance between wavelengths of 360 to 830 nm, the average absorbance between wavelengths of 450 to 480 nm, the average absorbance between wavelengths of 510 to 540 nm, and the average absorbance between wavelengths of 620 to 650 nm, obtained by measuring the ultraviolet-visible absorption spectrum of the colored resin layer contained in the cured dry film, and the above-mentioned relationship. [Math 3] (Abs. all: Average absorbance between wavelengths of 360 and 830 nm; Abs. 2: Average absorbance between wavelengths of 450 and 480 nm; Abs. 3: Average absorbance between wavelengths of 510 and 540 nm; Abs. 5: Average absorbance between wavelengths of 620 and 650 nm.)

14. The light-emitting electronic component according to claim 13, characterized in that the cured dry film further comprises a transparent resin layer having higher light transmittance than the colored resin layer, on the side further from the substrate than the colored resin layer.

15. The light-emitting electronic component according to claim 14, 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.

16. A step of placing the dry film according to any one of claims 1 to 12 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 colored curable resin layer 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 colored curable resin layer.

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