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

Abstract

The present invention provides a dry film and its cured product that fills the spaces between light-emitting elements with a light-absorbing resin at low cost without obstructing the light from the light-emitting elements from reaching the viewer, a light-emitting electronic component using this dry film, and a method for manufacturing the light-emitting electronic component. [Solution] A dry film 1 is pressed onto the surface on which multiple light-emitting elements are arranged in order to fill the gaps between the light-emitting elements of an element-equipped substrate 10 on which multiple light-emitting elements 12 to 14 are arranged on a substrate 11, and comprises a light-absorbing resin layer 3 that is in contact with the element-equipped substrate 10 when pressed, and a light-transmitting resin layer 2 on the opposite side, wherein the light-absorbing resin layer 3 has a total light transmittance of 0 to 10%, and the light-transmitting resin layer 2 has a total light transmittance of 50 to 100%.

Description

[Technical Field]

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

[0002] In recent years, display technologies using extremely small light-emitting diodes, known as mini-LEDs or micro-LEDs, have been attracting attention. Mini LEDs and micro LEDs have two applications. One is a technology that enables localized control of the brightness of a liquid crystal display by configuring the backlight with a large number of LEDs arranged on a substrate. The other method involves using LEDs of each color to emit light for the red (R), green (G), and blue (B) components that make up the pixels, and the high-purity colors emitted by each color LED are directly delivered to the eye.

[0003] Mini-LEDs and micro-LEDs use electronic components in which multiple light-emitting elements are arranged on a substrate. In such electronic components, a dry film is used to fill the spaces between the multiple light-emitting elements with a light-absorbing resin (Patent Document 1). Dry film is a resin film obtained by coating and drying a curable resin composition onto a carrier film. This film is then pressed onto the surface of a substrate on which light-emitting elements are arranged, filling the spaces between the light-emitting elements, and then cured.

[0004] When a dry film is pressed onto the surface of a substrate where light-emitting elements are arranged, a light-absorbing resin layer is inevitably formed not only between the light-emitting elements but also on the light-emitting elements themselves. If the light-absorbing resin layer formed on the light-emitting element is left as is, it will not only cause light diffusion between the light-emitting elements, but also block the light that should be emitted towards the viewer. Therefore, Patent Document 1 describes a method in which, after pressing a dry film, the resin on the light-emitting element is removed by etching such as plasma treatment, and the exposed light-emitting element is covered with a light-transmitting encapsulant. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2022-22562 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] However, etching processes such as plasma treatment are extremely time-consuming, contributing to increased manufacturing costs. Furthermore, it is difficult to completely remove the resin from the light-emitting element through etching, making it challenging to completely prevent the diffusion of light that should be emitted towards the viewer. In view of the above circumstances, the present invention aims to provide a dry film that can fill the spaces between light-emitting elements with a light-absorbing resin at low cost without hindering light from the light-emitting elements from reaching the viewer, as well as a light-emitting electronic component using this dry film and a method for manufacturing the light-emitting electronic component. [Means for solving the problem]

[0007] The present invention encompasses the following embodiments. [1] A dry film that is pressed onto the surface of an element-equipped substrate on which a plurality of light-emitting elements are arranged, in order to fill the spaces between the plurality of light-emitting elements of an element-equipped substrate on which a plurality of light-emitting elements are arranged, A dry film comprising a light-absorbing resin layer positioned in contact with the substrate with the element during the aforementioned crimping process, and a light-transmitting resin layer laminated on the side of the light-absorbing resin layer opposite to the substrate with the element.

[0008] [2] The dry film according to [1], wherein the total light transmittance of the light-transmitting resin layer is greater than the total light transmittance of the light-absorbing resin layer. [3] The dry film according to [1] or [2], characterized in that the light-absorbing resin layer has a total light transmittance of 0 to 10%, and the light-transmitting resin layer has a total light transmittance of 50 to 100%.

[0009] [4] A dry film according to any one of [1] to [3], wherein at 100°C, the storage modulus of the light-transmitting resin layer is greater than the storage modulus of the light-absorbing resin layer, and at 150°C, the storage modulus of the light-transmitting resin layer is greater than the storage modulus of the light-absorbing resin layer. [5] The storage modulus of the light-absorbing resin layer is 1.0 × 10 at 100°C. 5 A dry film described in any of [1] to [4], having a Pa of or less. [6] The storage modulus of the light-transmitting resin layer is 1.0 × 10 at 100°C. 7 It is below Pa, and at 150°C it is 1.0 × 10⁻⁶ 5 The dry film described in any of [1] to [5] above. [7] The storage modulus of the light-transmitting resin layer is 1.0 × 10 at 150°C. 5 A dry film with a Pa of 1 or higher, as described in any of [1] to [6].

[0010] [8] A dry film according to any one of [1] to [7] wherein at least one of the light-absorbing resin layer and the light-transmitting resin layer comprises an epoxy resin. [9] A dry film according to any one of [1] to [8], wherein the light-absorbing resin layer contains an epoxy resin.

[10] A dry film according to any one of [1] to [9], wherein the light-transmitting resin layer contains an epoxy resin.

[0011]

[11] The dry film according to [8], wherein at least one of the light-absorbing resin layer and the light-transmitting resin layer comprises a modified elastomer having a functional group that can react with epoxy groups.

[12] The dry film according to [9], wherein the light-absorbing resin layer comprises a modified elastomer having a functional group that can react with epoxy groups.

[13] The dry film according to

[10] , wherein the light-transmitting resin layer comprises a modified elastomer having a functional group that can react with epoxy groups.

[0012]

[14] The dry film according to any one of

[11] to

[13] , wherein the modified elastomer having a functional group capable of reacting with the epoxy group is an acid-modified elastomer.

[15] The dry film according to any one of

[11] to

[13] , wherein the modified elastomer having a functional group capable of reacting with the epoxy group is acrylonitrile-butadiene rubber.

[0013]

[16] The dry film according to any one of [1] to

[15] , wherein at least one of the light-absorbing resin layer and the light-transmitting resin layer contains carbon black.

[17] The dry film according to

[16] , wherein the carbon black is gas black.

[18] The dry film according to any one of [1] to

[17] , wherein the light-absorbing resin layer does not contain an inorganic filler other than carbon black.

[19] The dry film according to any one of [1] to

[18] , wherein the light-transmitting resin layer does not contain an inorganic filler other than carbon black.

[20] The dry film according to any one of [1] to

[18] , wherein the light-transmitting resin layer does not contain an inorganic filler including carbon black.

[0014]

[21] A cured product obtained by curing the dry film according to any one of [1] to

[20] .

[22] A light-emitting electronic component comprising a substrate, a plurality of light-emitting elements disposed on the substrate, and the cured product according to

[21] filled between the plurality of light-emitting elements.

[0015]

[23] A method for manufacturing a light-emitting electronic component, wherein the dry film according to any one of [1] to

[20] is disposed on the surface of the element-attached substrate on which the plurality of light-emitting elements are disposed such that the light-absorbing resin layer is in contact therewith, press-bonded at 80 to 120 °C to fill the dry film between the plurality of light-emitting elements, and heated at 100 to 160 °C to cure the dry film.

[0016]

[24] The method for manufacturing a light-emitting electronic component according to

[23] , wherein the thickness of the light-absorbing resin layer before bonding is 10 to 90% of the height of the light-emitting element.

[25] The method for manufacturing a light-emitting electronic component according to

[23] or

[24] , wherein the thickness of the light-transmitting resin layer before bonding is 10 to 200% of the height of the light-emitting element.

[26] A method for manufacturing a light-emitting electronic component according to any one of

[23] to

[25] , wherein the total thickness of the light-absorbing resin layer and the light-transmitting resin layer before bonding is 100 to 290% of the height of the light-emitting element. [Effects of the Invention]

[0017] The dry film of the present invention allows for the low-cost filling of light-absorbing resin between light-emitting elements without obstructing the light from the light-emitting elements from reaching the viewer. Furthermore, the cured product of the present invention prevents light diffusion between light-emitting elements while not hindering light from the light-emitting elements from reaching the viewer. Furthermore, according to the present invention, the light-emitting electronic component and the method for manufacturing the light-emitting electronic component can be made in which light diffusion between light-emitting elements is prevented while the arrival of light to the viewer is not obstructed. [Brief explanation of the drawing]

[0018] [Figure 1] This is a schematic cross-sectional view of a dry film according to one embodiment of the present invention. [Figure 2] This is a schematic diagram illustrating a method for manufacturing a light-emitting electronic component according to one embodiment of the present invention. [Figure 3] This is a schematic diagram illustrating a method for manufacturing a light-emitting electronic component according to one embodiment of the present invention. [Figure 4] This is a schematic diagram illustrating a method for manufacturing a light-emitting electronic component according to one embodiment of the present invention. [Figure 5] This is a schematic diagram illustrating a method for manufacturing a light-emitting electronic component according to one embodiment of the present invention. [Figure 6] This is a schematic diagram illustrating a method for manufacturing a light-emitting electronic component according to one embodiment of the present invention. [Modes for carrying out the invention]

[0019] In this specification and in the claims, “main component” means a component that accounts for 50% or more by mass of the total solid content of the entire composition. “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 the “~” as the lower and upper limits, respectively.

[0020] <Dry film> A dry film 1 according to one aspect of the present invention will be described with reference to Figures 1 and 2. As shown in Figure 1, the dry film 1 is made up of a laminated light-transmitting resin layer 2 and a light-absorbing resin layer 3. Furthermore, for ease of handling, the dry film 1 is formed sandwiched between a first carrier film 4 and a second carrier film 5. Specifically, the light-transmitting resin layer 2, the light-absorbing resin layer 3, and the second carrier film 5 are sequentially laminated on the first carrier film 4.

[0021] As shown in Figure 2, the dry film 1 is used to fill the spaces between multiple light-emitting elements (light-emitting elements 12, 13, and 14) in an element-equipped substrate 10 on which multiple light-emitting elements are arranged on a substrate 11. Details of the element-equipped substrate 10 will be described later. When the dry film 1 is pressed, as shown in Figure 2, the light-absorbing resin layer 3 is in contact with the substrate 10 with the element, and the light-transmitting resin layer 2 is positioned on the opposite side of the light-absorbing resin layer 3 from the substrate 10 with the element.

[0022] The light-absorbing resin layer 3 prevents light diffusion between light-emitting elements. The light-transmitting resin layer 2 presses the light-absorbing resin layer 3 between the light-emitting elements. Since the light-transmitting resin layer 2 does not prevent light from the light-emitting elements from reaching the viewer, it is not necessary to remove it by etching after the dry film 1 has been pressure-bonded and cured onto the substrate 10 with the elements. A specific method for obtaining a light-emitting electronic component by pressing a dry film 1 onto a substrate 10 with elements will be described later.

[0023] <Light-absorbing resin layer> The light-absorbing resin layer 3 has a low total light transmittance and is a layer that prevents light diffusion between light-emitting elements after curing. Also, in the thermocompression bonding process, it sufficiently fills the spaces between the plurality of light-emitting elements arranged on the substrate 10 with elements, and is a layer for preventing appearance defects due to the expansion of unfilled voids in the thermosetting process and damage to the light-emitting elements due to external factors in subsequent processes.

[0024] [Total light transmittance] The light-absorbing resin layer 3 is preferably prepared so that the total light transmittance is 0 to 10%, more preferably 0 to 5%, and even more preferably adjusted to 0 to 1%. The lower the total light transmittance, the more preferable it is because even if the thickness of the light-absorbing resin layer 3 fluctuates, the influence on the light diffusion prevention function is small.

[0025] When the total light transmittance of the light-absorbing resin layer 3 is below the upper limit value, light diffusion between the light-emitting elements can be prevented. The total light transmittance in this specification can be measured in accordance with JIS K 7361 using a haze meter NDH5000 (manufactured by Nippon Denshoku Industries Co., Ltd.).

[0026] [Storage elastic modulus] The storage elastic modulus of the light-absorbing resin layer 3 is preferably smaller than the storage elastic modulus of the light-transmissive resin layer 2. The storage elastic modulus of the light-absorbing resin layer 3 is preferably 1.0×10 5 Pa or less at 100 °C, preferably 1.0×10 5 ~1.0×10 2 Pa, and more preferably 5.0×10 4 ~1.0×10 3 Pa.

[0027] By having a storage modulus of the light-absorbing resin layer 3 at 100°C that is below a preferred upper limit, sufficient fluidity is obtained when bonding to the element-mounted substrate 10, and the light-absorbing resin layer 3 is less likely to remain on the light-emitting element. Furthermore, it can follow the unevenness of the element-mounted substrate 10 caused by multiple light-emitting elements, and adequately fill the spaces between the multiple light-emitting elements. By having a storage modulus of the light-absorbing resin layer 3 at 100°C that is above a preferred lower limit, uneven pressure distribution during thermocompression bonding can be prevented, and a uniform appearance can be maintained. Furthermore, leakage of resin outside the range can be prevented, and the film thickness after bonding can be ensured.

[0028] [Curable resin composition] The light-absorbing resin layer 3 is preferably composed of a curable resin composition. Examples of curable resin compositions include epoxy resin compositions, amide resin compositions, phenol resin compositions, polyimide resin compositions, maleimide resin compositions, cyanate resin compositions, and oxazine resin compositions.

[0029] In particular, epoxy resin compositions are preferred because they can achieve curing at low temperatures and have excellent heat resistance and reliability. In this specification, an epoxy resin composition is a composition mainly comprising an epoxy resin, or a composition mainly comprising an epoxy resin and an elastomer.

[0030] (Epoxy resin) In this specification and in the claims, an epoxy resin is a compound having epoxy groups in its molecule. In the present invention, epoxy resins having two or more epoxy groups in a single molecule are preferred. This is because a crosslinked structure can be formed through polymerization reactions between epoxy resins or reactions between the epoxy resin and a modified elastomer 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 modified elastomer having functional groups that can react with epoxy groups is sufficient, resulting in a cured product with sufficient heat resistance.

[0031] Examples of epoxy resins include bifunctional epoxy resins having two epoxy groups in the molecule, polyfunctional epoxy resins having three or more epoxy groups in the molecule, and high molecular weight epoxy resins with a weight-average molecular weight of 10,000 or more. Hydrogenated epoxy resins of these types may also be used. In this specification and in the claims, high molecular weight epoxy resins are classified as high molecular weight epoxy resins, regardless of the number of epoxy groups in the molecule, and are not classified as difunctional epoxy resins or polyfunctional epoxy resins. The weight-average molecular weight of epoxy resin is the molecular weight in polystyrene terms, measured by gel permeation chromatography.

[0032] Examples of epoxy resins include bisphenol A type epoxy resin, bisphenol F type epoxy resin, or phenoxy type epoxy resins which are high molecular weight versions thereof, and hydrogenated versions thereof; glycidyl ester epoxy resins such as diglycidyl phthalate, diglycidyl isophthalate, diglycidyl terephthalate, glycidyl p-hydroxybenzoate, diglycidyl tetrahydrophthalate, diglycidyl succinate, diglycidyl adipic acid, diglycidyl sebacate, and triglycidyl trimellitic acid; ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, Examples of glycidyl ether epoxy resins include, but are not limited to, 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, trimethylolpropane triglycidyl ether, pentaerythritol tetraglycidyl ether, tetraphenyl glycidyl ether ethane, triphenyl glycidyl ether ethane, sorbitol polyglycidyl ether, and polyglycerol polyglycidyl ether; glycidylamine epoxy resins such as triglycidyl isocyanurate and tetraglycidyldiaminodiphenylmethane; and linear aliphatic epoxy resins such as epoxidized polybutadiene and epoxidized soybean oil. Novolac-type epoxy resins such as xylene structure-containing novolac epoxy resin, naphthol novolac-type epoxy resin, phenol novolac epoxy resin, o-cresol novolac epoxy resin, and bisphenol A novolac epoxy resin can also be used.

[0033] Furthermore, examples of epoxy resins that can be used include 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, bisphenol S type epoxy resin, and the like.

[0034] As high molecular weight epoxy resins, phenoxy epoxy 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.

[0035] Among the epoxy resins mentioned above, a polyfunctional epoxy resin is preferred as the epoxy resin used in the light-absorbing resin layer 3, from the viewpoint of increasing the crosslinking density after curing. Among polyfunctional epoxy resins, novolac-type epoxy resins are particularly preferable because they allow for the introduction of a moderately flexible skeleton, enabling adjustment of flexibility and softening point. This makes the cured product less susceptible to brittle fracture, improving the stability of the performance of the cured epoxy resin composition over long-term use, increasing the crosslinking density, and improving heat resistance.

[0036] 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-690," "N-695," and "HP-7200H" from DIC Corporation.

[0037] The amount of polyfunctional epoxy resin blended in the light-absorbing resin layer 3 is preferably 10 to 99% by mass, more preferably 40 to 95% by mass, and even more preferably 60 to 90% by mass, based on 100% by mass of the total resin solids content of the light-absorbing resin layer 3. 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 light-absorbing resin layer 3 can be ensured.

[0038] The light-absorbing resin layer 3 preferably does not contain high molecular weight epoxy resin, or if it does, it is preferably contained in a smaller amount than the light-transmitting resin layer 2. This makes it easier to ensure sufficient fluidity during heat bonding. The amount of high molecular weight epoxy resin blended in the light-absorbing resin layer 3 is preferably less than 50% by mass, more preferably less than 30% by mass, and even more preferably less than 10% by mass, based on 100% by mass of the total resin solids content of the light-absorbing resin layer 3.

[0039] From the viewpoint of ensuring sufficient fluidity during thermocompression bonding, it is preferable that the light-absorbing resin layer 3 contains an epoxy resin with a softening or melting point of 100°C or lower. From the viewpoint of handling properties and heat resistance of the cured product, it is more preferable that it contains an epoxy resin with a softening or melting point of 50 to 95°C. By including an epoxy resin having a softening or melting point within the above range, it becomes possible to control the storage modulus.

[0040] The total amount of epoxy resin in the light-absorbing resin layer 3 is preferably 10 to 100% by mass, more preferably 20 to 99% by mass, and even more preferably 35 to 95% by mass, based on 100% by mass of the total resin solids content of the light-absorbing resin layer 3. Within this range, it is possible to control the storage modulus and ensure appropriate fluidity during heat bonding. Furthermore, if it is above the lower limit, the heat resistance after curing can be improved.

[0041] (Elastomer) The light-absorbing resin layer 3 preferably contains an elastomer in addition to a resin such as epoxy resin. The inclusion of an elastomer facilitates control of the storage modulus, i.e., control of fluidity, allowing for more reliable filling between light-emitting elements. Furthermore, it prevents uneven pressure distribution during thermal bonding, maintaining a uniform appearance. Additionally, it prevents resin from flowing out of the specified area, ensuring sufficient film thickness after bonding.

[0042] As for the 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 because it has good compatibility with epoxy resin, allows control of the fluidity of the light-absorbing resin layer 3 around 100°C, and has good adhesion to the light-transmitting resin layer 2 and the element-equipped substrate 10.

[0043] 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 above the lower limit, the storage modulus of the light-absorbing resin layer 3 can be controlled, and fluidity during thermal bonding can be ensured. If the weight-average molecular weight of the elastomer is below the upper limit, the compatibility with the epoxy resin is improved, and the flow during thermal curing can be controlled more effectively.

[0044] In particular, when the light-absorbing resin layer 3 is composed of an epoxy resin composition, it is preferable to include a modified elastomer having functional groups that can react with epoxy groups. If a modified elastomer having functional groups that can react with epoxy groups is present, it also acts as a curing agent for the epoxy resin. Furthermore, because it can react and bond with the epoxy resin, its heat resistance and reliability against thermal shock are improved. In addition, the difference in polarity between the functional groups that can react with the epoxy resin and the resin skeleton has a good effect on dispersibility, and good dispersibility can be obtained when carbon black is included in the light-absorbing resin layer 3.

[0045] 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, and carboxyl groups or carboxylic acid anhydride groups are particularly preferred.

[0046] In other words, when the light-absorbing resin layer 3 is composed of an epoxy resin composition, it is preferable to contain an acid-modified elastomer having acid groups or acid anhydride groups, and more preferable to contain an acid-modified elastomer having carboxyl groups. It is particularly preferable to contain modified NBR having carboxyl groups.

[0047] 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 Nipol® NX775 and Nipol 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.

[0048] It is preferable that the amount of elastomer in the light-absorbing resin layer 3 is greater than the amount of elastomer in the light-transmitting resin layer 2. This allows the storage modulus of the light-absorbing resin layer 3 during thermal bonding to be adjusted to an appropriate range lower than that of the light-transmitting resin layer 2, especially in formulations where the light-absorbing resin layer 3 contains a large amount of low molecular weight components such as polyfunctional epoxy. It also suppresses flow during thermal curing. As a result, it becomes possible to suppress flow during thermal curing while maintaining sufficient fluidity in the light-absorbing resin layer 3 during thermal bonding.

[0049] The amount of elastomer in the light-absorbing resin layer 3 is preferably 0.01 to 90% by mass, more preferably 1 to 80% by mass, and even more preferably 5 to 65% by mass, based on 100% by mass of the total resin solids content of the light-absorbing resin layer 3. Within this range, it is possible to control the storage modulus and ensure appropriate fluidity during thermocompression bonding. Furthermore, above the lower limit, the dispersibility of carbon black improves. In addition, film formation is improved, and the film thickness distribution can be narrowed when coating and forming a film with the epoxy resin composition. From the viewpoint of suppressing flow during thermal curing, it is even more preferable that the amount of elastomer in the light-absorbing resin layer 3 be 25% by mass or more relative to 100% by mass of the total resin solids content of the light-absorbing resin layer 3.

[0050] (Hardening agent) When the light-absorbing resin layer 3 is composed of an epoxy resin composition, it may contain other curing agents for epoxy resins other than modified elastomers having functional groups 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. Other hardening agents may be used in combination of two or more types.

[0051] (curing catalyst) If the light-absorbing resin layer 3 is composed of an epoxy resin composition, it may also contain a curing catalyst that promotes the curing reaction of the epoxy resin. Examples of curing catalysts include imidazole-based, tertiary amine-based, and phosphorus compound-based catalysts. Among these, imidazole-based catalysts are preferred because they have good compatibility with epoxy resins and are less likely to cause yellowing. Among imidazole-based curing catalysts, those having a cyanoethyl group are particularly preferred because they dissolve easily in epoxy resins.

[0052] 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 light-absorbing resin layer 3. Within this range, curing can proceed sufficiently, and the pot life of the dry film 1 can be ensured. Two or more curing catalysts may be used in combination.

[0053] (Carbon Black) The light-absorbing resin layer 3 is preferably colored black, and may contain carbon black for coloring. By including carbon black, it absorbs light that causes interference between the multiple light-emitting elements of the substrate 10 with the elements, thereby preventing light diffusion.

[0054] The particle size of the carbon black is preferably 10 to 500 nm, more preferably 10 to 300 nm, and particularly preferably 10 to 100 nm. Note that the particle size refers to the average particle size and can be determined using a dynamic light scattering measurement device. An example of a dynamic light scattering measurement device is the NanotracWave II UT151 manufactured by Microtrac-Bell.

[0055] As the carbon black, one or more known types of carbon black, such as gas black, channel black, furnace black, thermal black, and lamp black, can be used. Resin-coated carbon black may also be used. Furthermore, carbon nanofibers and carbon nanotubes may be used.

[0056] Among these, gas black is preferred because it has a large amount of surface functional groups, high dispersibility, and exhibits sufficient light diffusion prevention function with only a small amount added. Furthermore, when the light-absorbing resin layer 3 contains a modified elastomer having functional groups that can react with epoxy resin, the interaction between the surface functional groups of gas black and the functional groups of the modified elastomer having functional groups that can react with epoxy resin further enhances dispersibility, ensuring good light diffusion prevention and coating stability.

[0057] The amount of carbon black added is preferably 0.1 to 15 parts by mass, and more preferably 1.0 to 10 parts by mass, per 100 parts by mass of the total resin solids of the light-absorbing resin layer 3. Sufficient light shielding can be obtained if the amount of carbon black added is equal to or greater than the lower limit. If the amount of carbon black added exceeds the upper limit, the thixotropy of the light-absorbing resin layer 3 increases, reducing its fluidity during thermocompression bonding, and making it impossible to adequately fill the spaces between the multiple light-emitting elements of the element-equipped substrate 10.

[0058] (Other ingredients) The light-absorbing resin layer 3 may contain inorganic fillers to improve flame retardancy and heat resistance and to adjust the refractive index. However, it is preferable that it does not contain inorganic fillers other than carbon black, as this increases thixotropy and reduces fluidity during thermal bonding, making it difficult to adequately fill the spaces between multiple light-emitting elements on the substrate 10 with the elements. The light-absorbing resin layer 3 may further contain, if necessary, resins other than epoxy resin and elastomer, thickeners, defoamers and / or leveling agents, coupling agents and other adhesion-enhancing agents, and flame retardants.

[0059] <Light-transparent resin layer> The light-transmitting resin layer 2 is a layer used in the thermocompression bonding process to sufficiently press the light-absorbing resin layer 3 between the multiple light-emitting elements arranged on the element-equipped substrate 10. Furthermore, it has a high total light transmittance and does not prevent light from the light-emitting elements between the elements from reaching the viewer after curing.

[0060] [Total light transmittance] The light-transmitting resin layer 2 is preferably prepared to have a total light transmittance of 50-100%, more preferably 70-99.5%, and even more preferably 80-99%. A higher total light transmittance of the light-transmitting resin layer 2 is preferable because it is less affected by variations in the thickness of the light-transmitting resin layer 2.

[0061] Because the total light transmittance of the light-transmitting resin layer 2 is above the lower limit, even if cured material of the light-transmitting resin layer 2 remains on the light-emitting element, it does not obstruct the reach of light to the viewer. Therefore, there is no need to remove it.

[0062] [Storage modulus] Preferably, the storage modulus of the light-transmitting resin layer 2 is greater than that of the light-absorbing resin layer 3 at temperatures between 100°C and 150°C. Furthermore, if the storage modulus of the light-transmitting resin layer 2 is greater than the storage modulus of the light-absorbing resin layer 3 at 100°C and 150°C, then typically the storage modulus of the light-transmitting resin layer 2 is greater than the storage modulus of the light-absorbing resin layer 3 across the entire temperature range from 100°C to 150°C.

[0063] The storage modulus of the light-transmitting resin layer 2 is 1.0 × 10⁻⁶ at 100°C. 7 It is preferable that it is less than or equal to Pa, and 1.0 × 10 7 ~1.0×10 4 It is preferable that it be Pa, 5.0 × 10 6 ~5.0×10 4 It is more preferable that it be Pa. By having the storage modulus of the light-transmitting resin layer 2 at 100°C within a preferred range, sufficient fluidity is obtained that does not hinder the flow of the light-absorbing resin layer 3 when it is pressed onto the element-mounted substrate 10. This allows the layer to follow the unevenness of the element-mounted substrate 10 caused by the multiple light-emitting elements and adequately fill the spaces between the multiple light-emitting elements.

[0064] If the storage modulus of the light-transmitting resin layer 2 at 100°C exceeds a preferred upper limit, the fluidity of the light-transmitting resin layer 2 becomes insufficient, preventing the light-absorbing resin layer 3 from being sufficiently pressed between multiple light-emitting elements. Furthermore, cracks may occur in the light-transmitting resin layer 2 during thermal bonding, making it prone to crack-like defects. If the storage modulus of the light-transmitting resin layer 2 at 100°C falls below a preferred lower limit, the fluidity of the light-transmitting resin layer 2 becomes too high, preventing it from sufficiently pushing away the light-absorbing resin layer 3 on the light-emitting elements. As a result, the light-shielding light-absorbing resin layer 3 remains on the light-emitting elements, hindering the reach of light to the viewer.

[0065] The storage modulus of the light-transmitting resin layer 2 is 1.0 × 10⁻⁶ at 150°C. 4 Preferably Pa or higher, 1.0 × 10 4 ~5.0×10 7 It is preferably Pa, 1.0 × 10 5 ~5.0×10 6 It is more preferable that it be Pa. If the storage modulus of the light-transmitting resin layer 2 at 150°C exceeds a preferred upper limit, cracks are more likely to occur due to curing shrinkage during thermal curing. By keeping the storage modulus of the light-transmitting resin layer 2 at 150°C above a preferred lower limit, flow during thermal curing can be suppressed, and post-curing appearance defects such as repellency can be prevented.

[0066] The storage modulus of the light-transmitting resin layer 2 at 100°C is preferably 10 to 1000 times, and more preferably 30 to 500 times, the storage modulus of the light-absorbing resin layer 3. The storage modulus of the light-transmitting resin layer 2 at 150°C is preferably 5 to 10000 times, and more preferably 10 to 1000 times, the storage modulus of the light-absorbing resin layer 3. Furthermore, if the storage modulus of the light-transmitting resin layer 2 is greater than the storage modulus of the light-absorbing resin layer 3 at 100°C and 150°C, then typically the storage modulus of the light-transmitting resin layer 2 is greater than the storage modulus of the light-absorbing resin layer 3 across the entire temperature range from 100°C to 150°C.

[0067] [Curable resin composition] The light-transmitting resin layer 2 is preferably composed of a curable resin composition. Examples of curable resin compositions include those similar to those used for the light-absorbing resin layer 3. Among these, an epoxy resin composition is preferred because it enables curing at low temperatures and exhibits excellent heat resistance and reliability.

[0068] (Epoxy resin) Examples of epoxy resins used in the light-transmitting resin layer 2 include those of the same type as those used in the light-absorbing resin layer 3. From the viewpoint of imparting an appropriate viscosity to the light-transmitting resin layer 2 during bonding, it is preferable that the light-transmitting resin layer 2 contains a high molecular weight epoxy resin.

[0069] The weight-average molecular weight of the high molecular weight epoxy resin contained in the light-transmitting resin layer 2 is preferably 10,000 to 100,000. This allows the light-transmitting resin layer 2 to have an appropriate viscosity during bonding, enabling the light-absorbing resin layer 3 to be sufficiently pressed in during thermal bonding. Furthermore, it suppresses flow during thermal curing, reduces the appearance defects after curing such as repellency, and minimizes interference when etching is performed in a subsequent process.

[0070] It is more preferable to include a high molecular weight epoxy resin with a weight-average molecular weight of 10,000 to 35,000, from the viewpoint of good compatibility with other resin components, enabling a high total light transmittance of the light-transmitting resin layer 2, and allowing dissolution without mixing in high-boiling-point solvents that may remain in the dry film after drying.

[0071] By including a high molecular weight epoxy resin with a weight-average molecular weight of 10,000 to 100,000 as the epoxy resin used in the light-transmitting resin layer 2, it has an appropriate viscosity when heated, allowing the storage modulus of the light-transmitting resin layer 2 in the 100°C to 150°C range to be adjusted to a desirable range. For the light-transmitting resin layer 2, a phenoxy-type epoxy resin is preferred because it has good compatibility with other epoxy resins and can increase the total light transmittance of the light-transmitting resin layer 2.

[0072] Phenoxy epoxy resins have a relatively large molecular weight compared to other epoxy resins and possess a suitable viscosity when heated. This allows for the adjustment of the storage modulus of the light-transmitting resin layer 2 in the 100°C to 150°C range to a desirable range, ensuring sufficient indentation of the light-absorbing resin layer 3 during thermal bonding and suppressing appearance defects during thermal curing. Furthermore, unlike other thermoplastic resins such as polyester, phenoxy epoxy resins can be cured as epoxy resins, allowing for increased crosslinking density and maintaining the heat resistance and reliability of the cured product's performance over long-term use. From the viewpoint of ensuring the storage modulus that compresses the light-absorbing resin layer 3 during thermal bonding, it is preferable that the glass transition temperature of the phenoxy epoxy resin used in the light-transmitting resin layer 2 be 100°C or higher.

[0073] Specific examples of phenoxy epoxy resins include, for example, "1256," "YX7200," "YX8100," and "YX7180" from Mitsubishi Chemical Corporation, "YP-50," "YP-50S," and "YP-70" from Nippon Steel Chemical & Material Corporation, and "N-690," "H-157," and "EXA-192" from DIC Corporation.

[0074] The amount of high molecular weight epoxy resin blended in the light-transmitting resin layer 2 is preferably 30 to 80% by mass, more preferably 40 to 70% by mass, and even more preferably 45 to 60% by mass, based on 100% by mass of the total resin solids content of the light-transmitting resin layer 2.

[0075] Within the above range, the storage modulus can be controlled, and the light-absorbing resin layer 3 can be pressed in during thermocompression bonding. Furthermore, flow during thermosetting can be suppressed, preventing post-curing appearance defects such as repellency, and minimizing interference when etching is performed in subsequent processes. In addition, toughness is improved, making it less likely for crack-like defects to occur during thermocompression bonding. Furthermore, if the above upper limit is not met, the crosslinking density of the cured product of the light-transmitting resin layer 2 can be increased, improving heat resistance and chemical resistance. If the above blending amount is 45% or more, the total light transmittance of the light-transmitting resin layer 2 can be increased.

[0076] Furthermore, it is preferable that the epoxy resin used in the light-transmitting resin layer 2 includes a polyfunctional epoxy resin. By increasing the crosslinking density of the polyfunctional epoxy resin, the stability of the performance of the cured epoxy resin composition for long-term use is further improved, and the heat resistance is also improved. In addition, since it has a lower viscosity in the range of 100°C to 150°C than phenoxy epoxy resin, the storage modulus of the light-transmitting resin layer 2 can be adjusted by combining it with phenoxy epoxy resin.

[0077] 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-690," "N-695," and "HP-7200H" from DIC Corporation.

[0078] The amount of polyfunctional epoxy resin in the light-transmitting resin layer 2 is preferably 90% by mass or less, more preferably 10 to 80% by mass, and even more preferably 35 to 70% by mass, based on 100% by mass of the total resin solids content of the light-transmitting resin layer 2. Within this range, the storage modulus of the light-transmitting resin layer 2 during thermocompression bonding can be controlled, and the light-absorbing resin layer 3 can be sufficiently pressed in. Furthermore, heat resistance and chemical resistance can be imparted to the cured product.

[0079] From the viewpoint of ensuring sufficient fluidity during thermocompression bonding, it is preferable that the light-transmitting resin layer 2 contains an epoxy resin with a softening or melting point of 120°C or lower. From the viewpoint of handling properties and heat resistance of the cured product, it is more preferable that it contains an epoxy resin with a softening or melting point of 50 to 105°C. By including an epoxy resin having a softening or melting point within the above range, it becomes possible to control the storage modulus.

[0080] The total amount of epoxy resin in the light-transmitting resin layer 2 is preferably 10 to 100% by mass, more preferably 30 to 99% by mass, and even more preferably 50 to 95% by mass, based on 100% by mass of the total resin solids content of the light-transmitting resin layer 2. Within this range, it is possible to control the storage modulus and to sufficiently press the light-absorbing resin layer 3 during thermal bonding. Furthermore, it is possible to suppress flow during thermal curing, which suppresses defects in the appearance after curing, such as repulsion, and furthermore, it is less likely to cause problems when etching is performed in a subsequent process. In addition, if it is above the lower limit, the heat resistance after curing can be improved.

[0081] (Elastomer) The light-transmitting resin layer 2 preferably contains an elastomer in addition to a resin such as epoxy resin. Including an elastomer makes it easier to control the storage modulus. Examples of elastomers include those of the same type as those used for the light-absorbing resin layer 3. Among these, NBR is preferred because it has good compatibility with epoxy resin, can increase the total light transmittance of the light-transmitting resin layer 2, can increase the storage modulus of the light-transmitting resin layer 2 at around 150°C, and has good adhesion to the light-absorbing resin layer 3. The preferred weight-average molecular weight of the elastomer is also the same as that of the light-absorbing resin layer 3.

[0082] In particular, when the light-transmitting resin layer 2 is composed of an epoxy resin composition, it is preferable to include a modified elastomer having functional groups that can react with epoxy groups. If the modified elastomer has functional groups that can react with epoxy groups, it also acts as a curing agent for the epoxy resin. Furthermore, because it can react and bond with the epoxy resin, its heat resistance and reliability against thermal shock are improved.

[0083] Functional groups that can react with epoxy groups include those of the same type as those in the light-absorbing resin layer 3. 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 long pot life.

[0084] When the light-transmitting resin layer 2 is composed of an epoxy resin composition, it is particularly preferable that it contains modified NBR having a carboxyl group. Examples of modified NBR having a carboxyl group include those similar to the light-absorbing resin layer 3. Two or more modified elastomers having functional groups that can react with epoxy groups may be used in combination.

[0085] The amount of elastomer in the light-transmitting resin layer 2 is preferably 0 to 70% by mass, more preferably 1 to 50% by mass, and even more preferably 5 to 50% by mass, based on 100% by mass of the total resin solids content of the light-transmitting resin layer 2. Within this range, the storage modulus can be controlled. Furthermore, if it is below the upper limit, the light-absorbing resin layer 3 can be sufficiently pressed in during heat bonding. In addition, flow during heat curing can be suppressed, and defects in the appearance after curing, such as repelling, can be suppressed. Moreover, film-forming properties are improved, and the distribution of film thickness when coating and forming an epoxy resin composition can be narrowed.

[0086] From the viewpoint of improving compatibility with epoxy resin, thereby increasing the total light transmittance of the light-transmitting resin layer 2, and more effectively suppressing flow during thermal curing, it is even more preferable that the amount of elastomer in the light-transmitting resin layer 2 be less than 25% by mass relative to 100% by mass of the total resin solids content of the light-transmitting resin layer 2.

[0087] (Hardening agent) If the light-transmitting resin layer 2 is composed of an epoxy resin composition, it may 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 those similar to those used for the light-absorbing resin layer 3. Two or more of these other curing agents may be used in combination.

[0088] (curing catalyst) If the light-transmitting resin layer 2 is composed of an epoxy resin composition, it may also contain a curing catalyst to accelerate the curing reaction of the epoxy resin. Examples of curing catalysts include those similar to those used in the light-transmitting resin layer 2, and preferred embodiments are also similar.

[0089] 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 light-transmitting resin layer 2. Within this range, curing can proceed sufficiently, and the pot life of the dry film 1 can be ensured. Two or more curing catalysts may be used in combination.

[0090] (Other ingredients) The light-transmitting resin layer 2 may contain carbon black for color adjustment and other purposes. In that case, the amount of carbon black added is preferably less than 0.1 parts by mass, and more preferably 0.05 parts by mass or less, per 100 parts by mass of total resin solids. From the viewpoint of increasing the total light transmittance, it is particularly preferable that the light-transmitting resin layer 2 does not contain carbon black.

[0091] The light-transmitting resin layer 2 may contain inorganic fillers for the same reasons as the light-absorbing resin layer 3, but in addition to the same reasons as the light-absorbing resin layer 3, it is preferable that it does not contain inorganic fillers other than carbon black from the viewpoint of increasing the total light transmittance. The light-transmitting resin layer 2 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.

[0092] <Career Film> The first carrier film 4 and the second carrier film 5 (hereinafter, the first carrier film 4 and the second carrier film 5 may be collectively referred to simply as "carrier film") serve to protect the dry film 1, and are films to which a coating liquid of a curable resin composition is applied when forming the dry film 1.

[0093] As carrier films, for example, films made of thermoplastic resins such as polyester films like polyethylene terephthalate and polyethylene naphthalate, polyimide films, polyamide-imide films, polyethylene films, polytetrafluoroethylene films, polypropylene films, and polystyrene films, as well as surface-treated paper, can be used.

[0094] Among these, polyester film is suitably used from the viewpoint of heat resistance, mechanical strength, and handling. The thickness of the carrier film is not particularly limited, but is generally selected appropriately in the range of 10 to 150 μm depending on the application. The surface of the carrier film on which the resin layer is provided may be treated with a release agent.

[0095] <Method for manufacturing dry film> Dry film 1 is obtained by preparing a first carrier film 4 coated with a curable resin composition for the light-transmitting resin layer 2 and drying it, and a second carrier film 5 coated with a curable resin composition for the light-absorbing resin layer 3 and drying it, then stacking these so that the light-transmitting resin layer 2 and the light-absorbing resin layer 3 are in contact, and laminating them.

[0096] Each coating solution preferably contains an amount of organic solvent that results in a viscosity that allows for application without hindrance. There are no particular restrictions on organic solvents, 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. 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 other substances such as N,N-dimethylformamide (DMF), tetrachloroethylene, and turpentine oil. When incorporating carbon black into the coating solution, either carbon black powder or carbon black dispersion may be added.

[0097] Examples of coating methods include various types of 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, preferably 80 to 130°C, and more preferably 90 to 120°C.

[0098] 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 lamination temperature above the preferred lower limit, sufficient adhesion between the light-transmitting resin layer 2 and the light-absorbing resin layer 3 can be ensured, allowing for handling even before curing. Furthermore, by setting the lamination temperature below the preferred upper limit, the formation of air bubbles and wrinkles can be prevented.

[0099] Lamination can be performed using a roll laminator, press, vacuum press, etc. By laminating, a dry film 1 sandwiched between a first carrier film 4 and a second carrier film 5 is obtained, as shown in Figure 1.

[0100] <Substrate with this component> As shown in Figure 2, the element-equipped substrate 10 has multiple light-emitting elements arranged on the substrate 11. In Figure 2, etc., a schematic representation is shown of the portion where three light-emitting elements (light-emitting element 12, light-emitting element 13, and light-emitting element 14) are arranged.

[0101] There are no limitations on the material of the substrate 11, but known printed circuit boards can be suitably used. Examples of known printed circuit boards include glass epoxy substrates, fluororesin substrates, and ceramic substrates.

[0102] The light-emitting element is typically a light-emitting diode. The present invention is particularly suitable for cases where the light-emitting element is 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 substrate 10 with elements to obtain mini LEDs or micro LEDs, three colored light-emitting diodes (R, G, and B) can be used as light-emitting elements, or a blue light-emitting diode can be used as a light-emitting element.

[0103] <Manufacturing method for light-emitting electronic components> The present invention provides a method for manufacturing a light-emitting electronic component, which involves placing the dry film of the present invention on the surface of a substrate equipped with multiple light-emitting elements, such that its light-absorbing resin layer is in contact with the multiple light-emitting elements, pressing and pressing it at 80 to 120°C to fill the spaces between the multiple light-emitting elements with the dry film, and then heating it at 100 to 160°C to cure the dry film. The following describes a method for manufacturing a light-emitting electronic component according to one embodiment of the present invention, with reference to Figures 2 to 6.

[0104] In the manufacturing method of this embodiment, first, as shown in Figure 2, a dry film 1, in which the second carrier film 5 has been peeled off to expose the light-absorbing resin layer 3, is placed on the surface of the element-equipped substrate 10 on which the light-emitting elements 12, 13, and 14 are arranged, so that the light-absorbing resin layer 3 is in contact with the dry film 1. At this time, that is, before crimping, the thickness of the light-absorbing resin layer 3 is preferably 10 to 90% of the height of the light-emitting element. The lower limit is more preferably 30% or more, and even more preferably 50% or more. The upper limit is more preferably 85% or less, and even more preferably 70% or less.

[0105] If the thickness of the light-absorbing resin layer 3 is 10% or more of the height of the light-emitting element, a function to prevent light diffusion between light-emitting elements is obtained. If the thickness of the light-absorbing resin layer 3 is 30% or more of the height of the light-emitting element, the light-absorbing resin layer 3 can be sufficiently filled between the light-emitting elements. If the thickness of the light-absorbing resin layer 3 is 50% or more of the height of the light-emitting element, the amount of deformation of the light-transmitting resin layer 2 can be relatively reduced, and the occurrence of crack-like defects can be suppressed.

[0106] If the thickness of the light-absorbing resin layer 3 is 90% or less of the height of the light-emitting element, the light-absorbing resin layer 3 is less likely to remain on the light-emitting element during thermal bonding, and does not obstruct the light from the light-emitting element from reaching the viewer. If the thickness of the light-absorbing resin layer 3 is 85% or less of the height of the light-emitting element, leakage of the light-absorbing resin layer to the outside during thermal bonding can be prevented. If the thickness of the light-absorbing resin layer 3 is 70% or less of the height of the light-emitting element, the occurrence of variations in black density due to variations in the film thickness of the flowing light-absorbing resin layer 3 after thermal bonding can be prevented.

[0107] The thickness of the light-transmitting resin layer 2 before lamination is preferably 10 to 200% of the height of the light-emitting element. The lower limit is more preferably 40% or more, and even more preferably 60% or more. The upper limit is more preferably 170% or less, and even more preferably 140% or less.

[0108] If the thickness of the light-transmitting resin layer 2 is 10% or more of the height of the light-emitting element, the light-transmitting resin layer 2 can press into the light-absorbing resin layer 3, and by not leaving a shielding light-absorbing resin layer 3 on top of the light-emitting element, it does not prevent light from the light-emitting element from reaching the viewer. If the thickness of the light-transmitting resin layer 2 is 40% or more of the height of the light-emitting element, the light-absorbing resin layer 3 can be pressed uniformly during thermal bonding, preventing the occurrence of variations in black color due to fluctuations in the film thickness of the flowing light-absorbing resin layer 3. If the thickness of the light-transmitting resin layer 2 is 60-50% or more of the height of the light-emitting element, the light-absorbing resin layer 3 is less susceptible to deformation during thermal curing, making it less likely for appearance defects to occur.

[0109] If the thickness of the light-transmitting resin layer 2 is 200% or less of the height of the light-emitting element, a uniform film can be formed without differences in residual solvent concentration or unevenness in thermal history in the thickness direction. If the thickness of the light-transmitting resin layer 2 is 170% or less of the height of the light-emitting element, the volume ratio of the light-transmitting resin layer 2 flowing near the top surface of the light-emitting element during thermal bonding can be increased, allowing the light-absorbing resin layer 3 to be pushed away from the light-emitting element more efficiently. If the thickness of the light-transmitting resin layer 2 is 140% or less of the height of the light-emitting element, the total light transmittance of the light-transmitting resin layer 2 can be increased.

[0110] The total thickness of the light-transmitting resin layer 2 and the light-absorbing resin layer 3 before bonding is preferably 100-290% of the height of the light-emitting element, more preferably 125-255%, and even more preferably 130-210%. If the total thickness of the light-transmitting resin layer 2 and the light-absorbing resin layer 3 is equal to or greater than the above lower limit relative to the height of the light-emitting element, the light-absorbing resin layer 3 will not remain on the light-emitting element, and the light from the light-emitting element will not be prevented from reaching the viewer. If the total thickness of the light-transmitting resin layer 2 and the light-absorbing resin layer 3 is less than or equal to the above upper limit relative to the height of the light-emitting element, the thickness of the dry film on the light-emitting element can be reduced, and the amount of light that reaches the viewer from the light-emitting element can be improved.

[0111] The ratio of the thickness of the light-absorbing resin layer 3 before compression to the total thickness of the light-transmitting resin layer 2 and the light-absorbing resin layer 3 before compression is preferably 10 to 90%, more preferably 15 to 70%, and even more preferably 25 to 50%. If the ratio of the thickness of the light-absorbing resin layer 3 before bonding to the total thickness of the light-transmitting resin layer 2 and the light-absorbing resin layer 3 is equal to or greater than the lower limit, the light-transmitting resin layer 2 will sufficiently press into the light-absorbing resin layer 3, and the resin will be sufficiently filled between the light-emitting elements. If it is equal to or less than the upper limit, the light-transmitting resin layer 2 will not flow during heat bonding, suppressing flow during heat curing and preventing defects in the appearance after curing, such as streaks.

[0112] In the state shown in Figure 2, the dry film 1 is heat-pressed and embedded between the light-emitting elements as shown in Figure 3. In this case, it is preferable that the light-absorbing resin layer 3 has a relatively low storage modulus and ensures fluidity, as it can easily follow the irregularities caused by the light-emitting elements, fill the spaces between them, and do not easily remain on the light-emitting elements.

[0113] The temperature during heat bonding is 80-120°C, with 90-110°C being more preferable. Setting the temperature to 80°C or higher during heat bonding makes it easier to ensure the fluidity of the dry film 1. Setting the temperature to 120°C or lower during heat bonding reduces the risk of damage to the light-emitting element. Setting the temperature to 90-110°C during heat bonding allows for more precise control of fluidity, preventing the light-absorbing resin layer 3 from remaining on the light-emitting element and ensuring that light from the light-emitting element does not obstruct the viewer. It also suppresses the occurrence of unevenness and crack-like defects.

[0114] The pressure used in thermocompression bonding is preferably 0.05 to 1.0 MPa, and more preferably 0.1 to 0.5 MPa. By setting the pressure in thermocompression bonding to a value above the preferred lower limit, no light-absorbing resin layer 3 remains on the light-emitting element, and the light from the light-emitting element does not obstruct the viewer. By setting the pressure below the preferred upper limit, damage to the light-emitting element is minimized. Thermocompression bonding is preferably performed using a vacuum press capable of forming under vacuum. This makes it easier to avoid defects caused by air being incorporated into the resulting light-emitting electronic component.

[0115] After pressing, the first carrier film 4 is peeled off as shown in Figure 4, and then heat-cured to obtain the dry film 1 as a cured product 21 as shown in Figure 5. This yields the light-emitting electronic component 30. In Figure 5, the light-transmitting resin layer cured product 22 is the cured product of the light-transmitting resin layer 2, and the light-absorbing resin layer cured product 23 is the cured product of the light-absorbing resin layer 3.

[0116] The curing temperature is 100 to 160°C, with 120 to 150°C being preferred. By setting the curing temperature to 100°C or higher, the dry film 1 can be cured. By setting the curing temperature to 120°C or higher, the curing time of the dry film 1 can be shortened. Furthermore, by setting the curing temperature below the above upper limit, damage to the light-emitting element is less likely to occur. The curing time depends on the curing temperature, but is preferably 30 to 360 minutes, and more preferably 45 to 180 minutes. At the curing temperature, it is preferable that the light-transmitting resin layer 2 has a relatively high storage modulus and suppressed fluidity, as this suppresses defects in appearance after curing.

[0117] Finally, as shown in Figure 6, the light-emitting element is covered with the sealing material 31 to obtain the light-emitting electronic component 30. The method of covering with the sealing material 31 is not particularly limited; for example, a sealing material composition may be applied, or a dry film sealing material film may be laminated. [Examples]

[0118] The present invention will be described in detail below with reference to examples, but the present invention is not limited to the descriptions in these examples.

[0119] <Raw materials> The details of the raw materials used in each example and comparative example are as follows. [Epoxy resin] jER 1032H60: Manufactured by Mitsubishi Chemical Corporation, polyfunctional epoxy resin (solid), softening point 62°C, epoxy equivalent 168 g / eq. HP-7200H: Manufactured by DIC Corporation, cyclopentadiene novolac type polyfunctional epoxy resin (solid), softening point 82°C, epoxy equivalent 227 g / eq. jER YX7200B35: Manufactured by Mitsubishi Chemical Corporation, phenoxy epoxy resin (MEK solution, solid content 35% by mass), glass transition temperature 150°C, epoxy equivalent 8781 g / eq., weight-average molecular weight 30,000. jER 828EL: Manufactured by Mitsubishi Chemical Corporation, bisphenol A type bifunctional epoxy resin (liquid), epoxy equivalent 186 g / eq. NC-3000H: Manufactured by Nippon Kayaku Co., Ltd., bisphenyl novolac type polyfunctional epoxy resin (solid), softening point 71°C, epoxy equivalent 290 g / eq.

[0120] [Elastomer] NX775: Manufactured by Zeon Corporation, carboxy-modified nitrile rubber, weight-average molecular weight 208,000. • Teisan Resin SG-80H: Manufactured by Nagase ChemteX Corporation, acrylic ester copolymer resin (functional groups: epoxy group, amide group), MEK cut product, solids content 18% by mass, weight-average molecular weight 850,000.

[0121] [resin] • HF-1M: HF-1M manufactured by Meiwa Kasei Co., Ltd., a phenol novolac resin.

[0122] [Curing catalyst] • 2PZ-CN: Manufactured by Shikoku Chemicals Co., Ltd., 1-cyanoethyl-2-phenylimidazole. • 2E4MZ: Manufactured by Shikoku Chemicals Co., Ltd., 2-ethyl-4-methylimidazole.

[0123] [Carbon Black] • Special Black 4: Gas black manufactured by ORION ENGINEERED CARBONS.

[0124] [Additives] • KBM-403: Epoxysilane coupling agent manufactured by Shin-Etsu Silicone Co., Ltd.

[0125] [solvent] • MEK: Methyl ethyl ketone, manufactured by Junsei Chemicals. PGM: Propylene glycol monomethyl ether, manufactured by Junsei Chemicals.

[0126] <Preparation of coating solution for dry film> The raw materials in the formulations shown in Table 1 were mixed with a solvent of MEK / PGM = 80 / 20 to prepare a coating solution with a solid content concentration of 25% by mass. That is, the total amount of the raw materials in the formulations shown in Table 1 (in terms of solid content) was set to 25% by mass of the total amount of the resulting coating solution.

[0127] <Preparation and evaluation of single-layer sheets> Each coating solution was applied to the release surface of a release PET 1-TRE (manufactured by Nippa Co., Ltd., 50 μm) using a bar coater to achieve a dry film thickness of 40 μm. The sheets were dried at 120°C for 5 minutes to obtain a single-layer sheet in which the coating film of each solution was supported on the release PET.

[0128] The total light transmittance of the coating film on the obtained single-layer sheet was measured using a haze meter NDH5000 manufactured by Nippon Denshoku Industries Co., Ltd., in accordance with JIS K 7361. For the case of a single-layer PET release film, the transmitted light was defined as 100% transmittance. Furthermore, the storage modulus of the coating film on the obtained single-layer sheet at 100°C and 150°C 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. The results are shown in Table 1.

[0129] [Table 1]

[0130] <Examples> Each coating solution was applied to the release surface of a release PET 1-TRE (manufactured by Nippa Co., Ltd., 50 μm) using a bar coater so that the dry film thickness was as shown in Table 2. The sheets were dried at 120°C for 5 minutes to obtain a single-layer sheet for a light-transmitting resin layer in which the light-transmitting resin layer was supported on the release PET, and a single-layer sheet for a light-absorbing resin layer in which the light-absorbing resin layer was supported on the release PET. Each single-layer sheet was stacked so that the light-transmitting resin layer and the light-absorbing resin layer were in contact, and laminated using a roll laminator at 60°C to create a dry film laminate in which release PET, light-transmitting resin layer, light-absorbing resin layer, and release PET were sequentially layered.

[0131] <Comparative Example> A coating solution was applied to the release surface of a release PET 1-TRE (manufactured by Nippa Co., Ltd., 50 μm) using a bar coater to achieve the dry film thickness shown in Table 2. The sheet was dried at 120°C for 5 minutes to obtain a comparative single-layer sheet in which a single layer of dry film was supported on the release PET.

[0132] <Evaluation component-equipped substrate> A substrate with multiple LED light-emitting elements, each measuring 0.1 × 0.2 mm and 65 μm in height, arranged on an epoxy glass substrate was used as the evaluation substrate.

[0133] <Evaluation of the dry film in the example> The release PET in contact with the light-absorbing resin layer of the dry film laminate was peeled off, and the light-absorbing resin layer was positioned so that it was in contact with the LED light-emitting element. Subsequently, a dry film was filled between the light-emitting elements using a vacuum press under the conditions of 100 hPa vacuum, 100°C, 0.36 MPa, and 3 minutes. After peeling off the release PET in contact with the light-transmitting resin layer, the film was heat-cured by heating in a 150°C oven for 1 hour.

[0134] [Residue on the light-absorbing resin layer of the element] The hardened surface was observed and evaluated according to the following criteria. The results are shown in Table 2. ◎: No residue of the light-absorbing resin layer is visible on the light-emitting element. ○: A small amount of residue from the light-absorbing resin layer is visible on top of the light-emitting element, but almost none remains. ×: Residue of the light-absorbing resin layer is visible on the light-emitting element.

[0135] [Hibi's shortcomings] The hardened surface was observed and evaluated according to the following criteria. The results are shown in Table 2. ○: No defects such as cracks in the resin are observed. △: No cracks are visible in the resin, but whitening due to fine cracks is present. ×: Defects such as cracks in the resin are visible.

[0136] <Evaluation of the dry film in the comparative example> A comparative single-layer sheet was positioned so that the single-layer dry film was in contact with the LED light-emitting element. Subsequently, a dry film was filled between the light-emitting elements using a vacuum press under the conditions of 100 hPa vacuum, 100°C, 0.36 MPa, and 3 minutes. After peeling off the release PET, the film was heat-cured by heating in a 150°C oven for 1 hour. Similar to the examples, the surface was observed when the dry film was filled using a vacuum press, and its conformability was evaluated. Also, similar to the examples, the surface after curing was observed, and the light-absorbing resin layer residue and crack-like defects on the element were evaluated. The results are shown in Table 2.

[0137] [Table 2]

[0138] As shown in Table 2, the two-layer dry film according to the present invention showed virtually no residue of the light-absorbing resin layer on the light-emitting element, and was covered with a cured product of the light-transmitting resin layer. In contrast, the one-layer dry film of the comparative example showed residue of the light-absorbing resin layer on the light-emitting element, which needed to be removed by etching. [Explanation of Symbols]

[0139] 1 Dry film 2 Light-transparent resin layer 3. Light-absorbing resin layer 4. First Carrier Film 5. Second Carrier Film 10-element circuit board 11 circuit boards 12 Light-emitting elements 13 Light-emitting element 14 Light-emitting elements 21 Cured product 22 Light-transparent resin layer cured product 23. Cured light-absorbing resin layer 30 Light-emitting electronic components

Claims

1. A dry film that is pressed onto the surface of an element-equipped substrate on which multiple light-emitting elements are arranged, in order to fill the spaces between the multiple light-emitting elements of an element-equipped substrate on which multiple light-emitting elements are arranged, The system comprises a light-absorbing resin layer positioned in contact with the substrate with the element during the aforementioned crimping process, and a light-transmitting resin layer laminated on the side of the light-absorbing resin layer opposite to the substrate with the element. A dry film characterized in that at least one of the light-absorbing resin layer and the light-transmitting resin layer contains an epoxy resin.

2. The light-absorbing resin layer has a total light transmittance of 0 to 10%. The dry film according to claim 1, characterized in that the light-transmitting resin layer has a total light transmittance of 50 to 100%.

3. The dry film according to claim 1 or 2, wherein at 100°C, the storage modulus of the light-transmitting resin layer is greater than the storage modulus of the light-absorbing resin layer, and at 150°C, the storage modulus of the light-transmitting resin layer is greater than the storage modulus of the light-absorbing resin layer.

4. The storage modulus of the light-absorbing resin layer is 1.0 × 10 at 100°C. ５ It is less than or equal to Pa, The storage modulus of the light-transmitting resin layer is 1.0 × 10 at 100°C. ７ It is below Pa, and at 150°C it is 1.0 × 10⁻⁶ ５ A dry film according to claim 1 or 2, wherein the pressure is Pa or higher.

5. The dry film according to claim 1 or 2, wherein at least one of the light-absorbing resin layer and the light-transmitting resin layer comprises a modified elastomer having a functional group that can react with epoxy groups.

6. The dry film according to claim 1 or 2, wherein the light-absorbing resin layer contains carbon black.

7. A light-emitting electronic component comprising a substrate, a plurality of light-emitting elements arranged on the substrate, and a cured dry film according to claim 1 or 2 filled between the plurality of light-emitting elements.

8. On the surface of a substrate with multiple light-emitting elements arranged on the substrate, the dry film according to claim 1 or 2 is placed so that the light-absorbing resin layer is in contact with the surface on which the multiple light-emitting elements are arranged. The dry film is filled between the multiple light-emitting elements by pressing and pressing them at 80 to 120°C. A method for manufacturing light-emitting electronic components, comprising heating the dry film at 100 to 160°C to cure it.

9. The thickness of the light-absorbing resin layer before bonding is 10 to 90% of the height of the light-emitting element. The method for manufacturing a light-emitting electronic component according to claim 8, wherein the total thickness of the light-absorbing resin layer and the light-transmitting resin layer before bonding is 100 to 290% of the height of the light-emitting element.

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