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

Abstract

The present invention provides a dry film that ensures sufficient conformability for filling between light-emitting elements, suppresses appearance defects after curing, and is less likely to cause problems when etching is performed in a subsequent process, as well as a light-emitting electronic component using this dry film and a method for manufacturing a 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 optical 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 follow layer 3 that is in contact with the element-equipped substrate 10 when pressed, and a surface layer 2 on the opposite side, wherein the storage modulus of the surface layer 2 is greater than the storage modulus of the follow layer 3 at 100°C and 150°C.

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 resin (Patent Document 1). Dry film is a resin film obtained by coating a thermosetting resin composition onto a carrier film and drying it. 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. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2022-22562 [Overview of the project] [Problems that the invention aims to solve]

[0005] Mini-LEDs and micro-LEDs have extremely small light-emitting diodes (LEDs) arranged at a high density on the substrate. Therefore, the dry film used to bond the substrate to the surface on which the light-emitting elements are located requires high fluidity to conform to minute irregularities and fill the spaces between the light-emitting elements. To improve fluidity, it is conceivable to increase the amount of liquid components such as solvents and low-softening-point components in the dry film.

[0006] However, if a dry film with a large amount of residual solvent is used, a high curing temperature is required for curing and the evaporation of the residual solvent, resulting in significant damage to the substrate. Lowering the curing temperature to around 150 degrees Celsius to reduce damage requires a longer curing time, which increases production costs, energy consumption, and environmental impact.

[0007] Furthermore, the dry film from which residual solvent had been removed exhibited reduced conformability to steps during thermocompression bonding to fill the gaps between light-emitting elements. Therefore, when a liquid or a component with a low softening point was added to increase fluidity in order to ensure sufficient conformability, it was found that cosmetic defects such as bubbles and repellencies occurred in the cured appearance, resulting in problems where excess resin on the light-emitting elements could not be sufficiently removed in the subsequent etching process.

[0008] In view of the above circumstances, the present invention aims to provide a dry film that ensures sufficient conformability to fill between light-emitting elements even at a low curing temperature and short curing time, suppresses defects in appearance after curing, and does not cause problems when etching is performed in a subsequent process, as well as a light-emitting electronic component using this dry film and a method for manufacturing a light-emitting electronic component. [Means for solving the problem]

[0009] As a result of diligent research to achieve the above objectives, the inventors have discovered that the above objectives can be solved by providing a dry film with a follow-up layer that is in contact with the element-equipped substrate during bonding, and a surface layer laminated on the side of the follow-up layer opposite to the element-equipped substrate, and by making the storage modulus of the surface layer greater than that of the follow-up layer, thus completing the present invention.

[0010] 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 gaps between the plurality of light-emitting elements of an element-equipped substrate, comprising a follow layer that is in contact with the element-equipped substrate when pressed, and a surface layer laminated on the side of the follow layer opposite to the element-equipped substrate, wherein the storage modulus of the surface layer is greater than the storage modulus of the follow layer. [2] The dry film according to [1], wherein at 100°C, the storage modulus of the surface layer is greater than the storage modulus of the follow-up layer, and at 150°C, the storage modulus of the surface layer is greater than the storage modulus of the follow-up layer.

[0011] [3] The storage modulus of the follow layer is 1.0 × 10 at 100°C. 5 A dry film as described in [1] or [2], having a Pa of less than or equal to [2]. [4] The storage modulus of the surface layer is 1.0 × 10 at 100°C. 7 A dry film described in any of [1] to [3], having a Pa value of 0 or less. [5] The storage modulus of the surface 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 [4].

[0012] [6] A dry film according to any one of [1] to [5], wherein at least one of the follow-up layer and the surface layer comprises an epoxy resin. [7] A dry film according to any one of [1] to [6], wherein the follow-up layer contains an epoxy resin. [8] The dry film according to any one of [1] to [7], wherein the surface layer contains an epoxy resin.

[0013] [9] The dry film according to [6], wherein at least one of the follow layer and the surface layer contains a modified elastomer having a functional group capable of reacting with an epoxy group.

[10] The dry film according to [7], wherein the follow layer contains a modified elastomer having a functional group capable of reacting with an epoxy group.

[11] The dry film according to [8], wherein the surface layer contains a modified elastomer having a functional group capable of reacting with an epoxy group.

[0014]

[12] The dry film according to any one of [9] to

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

[13] The dry film according to any one of [9] to

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

[0015]

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

[13] , wherein at least the follow layer contains carbon black.

[15] The dry film according to

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

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

[15] , wherein the follow layer does not contain an inorganic filler other than carbon black.

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

[16] , wherein the surface layer does not contain an inorganic filler other than carbon black.

[0016]

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

[17] .

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

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

[0017]

[20] A method for manufacturing a light-emitting electronic component, comprising: placing a dry film according to any of [1] to

[17] on the surface of an element-equipped substrate on which a plurality of light-emitting elements are arranged, such that the follow layer is in contact with the dry film; pressing and pressing at 80 to 120°C to fill the spaces between the plurality of light-emitting elements with the dry film; and heating at 100 to 160°C to cure the dry film.

[0018]

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

[20] , wherein the thickness of the follow-up layer before crimping is 10 to 90% of the height of the light-emitting element.

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

[20] or

[21] , wherein the thickness of the surface layer before crimping is 10 to 150% of the height of the light-emitting element.

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

[20] to

[22] , wherein the total thickness of the follow-up layer and the surface layer before bonding is 100 to 160% of the height of the light-emitting element. [Effects of the Invention]

[0019] The dry film of the present invention has sufficient conformability to fill the spaces between light-emitting elements. Furthermore, it suppresses appearance defects after curing and is less likely to cause problems when etching is performed in a subsequent process. Furthermore, the cured dry film of the present invention is sufficiently filled between light-emitting elements while suppressing defects in appearance. Etching can also be performed without any problems. 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 the spaces between light-emitting elements are sufficiently filled with resin while suppressing defects in appearance. [Brief explanation of the drawing]

[0020] [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. [Figure 7] This is a schematic diagram illustrating a method for manufacturing a light-emitting electronic component according to one embodiment of the present invention. [Figure 8] 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]

[0021] 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.

[0022] <Dry film> A dry film 1 according to one aspect of the present invention will be described using Figures 1 and 2. As shown in Figure 1, the dry film 1 is made up of a laminated surface layer 2 and a follow-up 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 surface layer 2, the follow-up layer 3, and the second carrier film 5 are sequentially laminated on the first carrier film 4.

[0023] 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 follow-up layer 3 is in contact with the substrate 10 with the element, and the surface layer 2 is positioned on the opposite side of the follow-up layer 3 from the substrate 10 with the element.

[0024] Because the surface layer 2 and the follow-up layer 3 have different storage moduli, it is possible to achieve both fluidity during the bonding of the dry film 1 to the element-mounted substrate 10 and suppression of appearance defects after curing. As a result, even with a low curing temperature and short curing time, it is possible to manufacture light-emitting electronic components that can sufficiently fill the spaces between multiple light-emitting elements on the element-mounted substrate 10 and perform etching without any problems. A specific method for obtaining a light-emitting electronic component by pressing the dry film 1 onto the element-equipped substrate 10 will be described later.

[0025] <Follower layer> The follow-up layer 3 is a layer that, in the thermocompression bonding process, sufficiently fills the spaces between multiple light-emitting elements arranged on the element-equipped substrate 10, preventing appearance defects due to expansion of unfilled voids during the heat curing process and damage to the light-emitting elements due to external factors in subsequent processes.

[0026] [Storage modulus] The storage modulus of the follow-through layer 3 is 1.0 × 10⁻⁶ at 100°C. 5 It is preferable that it is Pa or less, and 1.0 × 10 5 Pa~1.0×10 2 It is preferable that it be Pa, 5.0 × 10 4 Pa~1.0×10 3 It is more preferable that it be Pa. By having a storage modulus of elasticity of the follow-up layer 3 at 100°C that is below a preferred upper limit, sufficient fluidity is obtained when pressing it onto the element-mounted substrate 10, allowing it to follow the irregularities of the element-mounted substrate 10 caused by multiple light-emitting elements and adequately fill the spaces between them. By having a storage modulus of elasticity of the follow-up 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 specified range can be prevented, ensuring sufficient film thickness after bonding.

[0027] [Thermosetting resin composition] The follow-up layer 3 is preferably composed of a thermosetting resin composition. Examples of thermosetting resin compositions include epoxy resin compositions, amide resin compositions, phenolic resin compositions, polyimide resin compositions, maleimide resin compositions, cyanate resin compositions, and oxazine resin compositions.

[0028] In particular, epoxy resin compositions are preferred because they can achieve thermosetting properties at low temperatures and offer 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.

[0029] (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.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] Among the epoxy resins mentioned above, a polyfunctional epoxy resin is preferred as the epoxy resin used for the follow-up 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.

[0035] 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.

[0036] The amount of polyfunctional epoxy resin in the follow-up 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 follow-up layer 3. If it is above the lower limit, the crosslinking density can be increased to impart chemical resistance and heat resistance. If it is below the upper limit, the storage modulus during thermocompression bonding can be adjusted, and the fluidity of the follow-up layer 3 can be ensured.

[0037] From the viewpoint of ensuring sufficient fluidity during heat-compression bonding, it is preferable that the follow-up 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.

[0038] The total amount of epoxy resin in the follow-up 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 follow-up 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.

[0039] (Elastomer) The follow-through layer 3 preferably contains an elastomer in addition to a resin such as epoxy resin. Including an elastomer makes it easier to control the storage modulus, i.e., control the fluidity.

[0040] 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 follow-through layer 3 around 100°C, and has good adhesion to the surface layer 2 and the element-equipped substrate 10.

[0041] 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, the storage modulus of the follow-up 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 above upper limit, the compatibility with the epoxy resin is improved, and the flow during thermal curing can be controlled more effectively.

[0042] In particular, when the follow-up 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 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. In addition, the difference in polarity between the functional groups that can react with the epoxy resin and the resin backbone has a good effect on dispersibility, and good dispersibility can be obtained when carbon black is included in the follow-up layer 3.

[0043] 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.

[0044] In other words, when the follow-up 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.

[0045] 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.

[0046] The amount of elastomer in the follow-up 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 follow-up layer 3. Within this range, it is possible to control the storage modulus and ensure appropriate fluidity during heat 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.

[0047] (Hardening agent) If the follow-up layer 3 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 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.

[0048] (curing catalyst) If the follow-up layer 3 is composed of an epoxy resin composition, it may also contain a curing catalyst to promote 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.

[0049] 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 follow-up 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.

[0050] (Carbon Black) The tracking layer 3 is preferably colored black, and may contain carbon black for coloring. By including carbon black, light shielding can be achieved between the multiple light-emitting elements of the element-equipped substrate 10, thereby preventing light diffusion.

[0051] 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.

[0052] 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.

[0053] 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 follow-up 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.

[0054] The blending amount of carbon black is preferably 0.1 to 15 parts by mass, more preferably 1.0 to 10 parts by mass, based on 100 parts by mass of the total resin solid content of the follower layer 3. When the blending amount of carbon black is at least the above lower limit value, sufficient light shielding properties can be obtained. When the blending amount of carbon black exceeds the above upper limit value, the thixotropy of the follower layer 3 increases, the fluidity during thermocompression bonding decreases, and it becomes impossible to sufficiently fill the spaces between the plurality of light-emitting elements of the substrate 10 with elements.

[0055] (Other components) The follower layer 3 can contain an inorganic filler for improving flame retardancy, heat resistance, and adjusting the refractive index. However, from the viewpoint that the thixotropy increases and the fluidity during thermocompression bonding decreases, making it impossible to sufficiently fill the spaces between the plurality of light-emitting elements of the substrate 10 with elements, it is preferable that the follower layer 3 does not contain inorganic fillers other than carbon black. The follower layer 3 can further use, as necessary, resins other than epoxy resins and elastomers, thickeners, defoamers and / or leveling agents, adhesion improvers such as coupling agents, flame retardants, etc.

[0056] <Surface layer> The surface layer 2 is a layer for sufficiently pushing the follower layer 3 into the spaces between the plurality of light-emitting elements arranged on the substrate 10 with elements in the thermocompression bonding process. Also, in the thermosetting process, it can prevent appearance defects such as bubbles and peeling, and make it less likely to cause problems even when an etching process is performed in a subsequent process.

[0057] [Storage elastic modulus] The storage elastic modulus of the surface layer 2 is greater than that of the follower layer 3 at 100°C to 150°C. When the storage elastic modulus of the surface layer 2 is greater than that of the follower layer 3 at 100°C and 150°C, usually in the entire range of 100°C to 150°C, the storage elastic modulus of the surface layer 2 is greater than that of the follower layer 3.

[0058] The storage elastic modulus of the surface layer 2 is preferably 1.0×10 7 Pa or less at 100°C, and 1.0×10 7Pa~1.0×10 4 It is preferable that it be Pa, 5.0 × 10 6 Pa~5.0×10 4 It is more preferable that it be Pa. If the storage modulus of the surface layer 2 at 100°C is within a preferred range, sufficient fluidity is obtained that does not hinder the flow of the follow-up layer 3 when it is pressed onto the substrate 10 with the elements, and it can follow the unevenness of the substrate 10 with the elements and sufficiently fill the spaces between the multiple light-emitting elements. If the storage modulus of the surface layer 2 at 100°C exceeds the preferred upper limit, the fluidity of the surface layer 2 will be insufficient, making it impossible to sufficiently press the follow-up layer 3 between the multiple light-emitting elements, and cracks will occur in the surface layer 2 during thermal bonding, making it prone to crack-like defects. If the storage modulus of the surface layer 2 at 100°C falls below the preferred lower limit, the fluidity of the surface layer 2 will be too high, resulting in an uneven surface shape on the surface of the surface layer 2 when the first carrier film 4 is peeled off after thermal bonding, resulting in a poor appearance, and making it prone to surface defects such as streaks during heat curing.

[0059] The storage modulus of surface layer 2 is 1.0 × 10⁻⁶ Pa at 150°C. 4 Preferably, it is 1.0 × 10 4 Pa ~ 5.0 × 10 Pa 7 Preferably, it is 1.0 × 10 5 Pa~5.0×10 6 It is more preferable that it be Pa. If the storage modulus of surface 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 surface layer 2 at 150°C above a preferred lower limit, flow during thermal curing can be suppressed, preventing post-curing appearance defects such as repellency, and furthermore, minimizing problems when etching is performed in a subsequent process.

[0060] The storage modulus of the surface layer 2 at 100°C is preferably 10 to 1000 times, and more preferably 30 to 500 times, the storage modulus of the follow-up layer 3. The storage modulus of the surface layer 2 at 150°C is preferably 5 to 10000 times, and more preferably 10 to 1000 times, the storage modulus of the follow-up layer 3. Furthermore, if the storage modulus of the surface layer 2 is greater than that of the follow-up layer 3 at 100°C and 150°C, then typically the storage modulus of the surface layer 2 is greater than that of the follow-up layer 3 across the entire temperature range from 100°C to 150°C.

[0061] [Thermosetting resin composition] The surface layer 2 is preferably composed of a thermosetting resin composition. Examples of thermosetting resin compositions include those similar to those used for the follow-through layer 3. Among these, an epoxy resin composition is preferred because it enables thermosetting at low temperatures and exhibits excellent heat resistance and reliability.

[0062] (Epoxy resin) Examples of epoxy resins used in surface layer 2 include those of the same type as those used in follow-up layer 3. From the viewpoint of imparting an appropriate viscosity to the surface layer 2 during bonding, it is preferable that the surface layer 2 contains a high molecular weight epoxy resin.

[0063] The weight-average molecular weight of the high molecular weight epoxy resin contained in the surface layer 2 is preferably 10,000 to 100,000. This allows the surface layer 2 to have an appropriate viscosity during compression, enabling the follow-up layer 3 to be sufficiently pressed in during thermal compression 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. It is more preferable to include an epoxy resin with a weight-average molecular weight of 10,000 to 35,000, from the viewpoint of good compatibility with other resin components and the ability to dissolve without mixing in high-boiling-point solvents that may remain in the dry film after drying.

[0064] 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 surface layer 2, it has an appropriate viscosity when heated, allowing the storage modulus of surface layer 2 in the 100°C to 150°C range to be adjusted to a desirable range. For the surface layer 2, a phenoxy-type epoxy resin is preferred due to its good compatibility with other epoxy resins.

[0065] Phenoxy epoxy resins have a relatively large molecular weight compared to other epoxy resins and possess a suitable viscosity when heated, allowing the storage modulus of the surface layer 2 in the 100°C to 150°C range to be adjusted to a desirable range. 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 periods of use. From the viewpoint of ensuring the storage modulus necessary to press the follow-up layer 3 during thermocompression bonding, it is preferable that the glass transition temperature of the phenoxy epoxy resin used in the surface layer 2 be 100°C or higher.

[0066] 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.

[0067] The amount of high molecular weight epoxy resin blended in the surface 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 surface layer 2.

[0068] Within the above range, the storage modulus can be controlled, ensuring that the storage modulus is sufficient to press the follow-up layer 3 during thermocompression bonding. Furthermore, flow during thermal curing can be suppressed, reducing the likelihood of 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 value is below the above upper limit, the crosslinking density of the cured surface layer 2 can be increased, improving heat resistance and chemical resistance.

[0069] Furthermore, it is preferable that the epoxy resin used in the surface layer 2 includes a polyfunctional epoxy resin. By increasing the crosslinking density, polyfunctional epoxy resins offer improved stability in the long-term performance of cured epoxy resin compositions and enhanced heat resistance. Furthermore, because they have a lower viscosity in the 100°C to 150°C range than phenoxy-type epoxy resins, combining them allows for adjustment of the storage modulus of the surface layer 2.

[0070] 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.

[0071] The amount of polyfunctional epoxy resin blended in the surface 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 surface layer 2. Within this range, the storage modulus of the surface layer 2 during thermocompression bonding can be controlled, and heat resistance and chemical resistance can be imparted to the cured product.

[0072] From the viewpoint of ensuring sufficient fluidity during thermocompression bonding, it is preferable that the surface 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.

[0073] The total amount of epoxy resin in the surface 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 surface layer 2. Within this range, it is possible to control the storage modulus and ensure that the storage modulus is sufficient to press the follow-up layer during thermal bonding. Furthermore, it is possible to suppress flow during thermal curing, which reduces the appearance defects after curing, such as repulsion, and also reduces the likelihood of problems occurring when etching is performed in a subsequent process. Moreover, if the value is above the lower limit, the heat resistance after curing can be improved.

[0074] (Elastomer) The surface 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 follow-up layer 3. Among these, NBR is preferred because it has good compatibility with epoxy resin, can increase the storage modulus of the surface layer 2 at around 150°C, and has good adhesion to the follow-up layer 3. The preferred weight-average molecular weight of the elastomer is also the same as that of the follow-up layer 3.

[0075] In particular, when the surface 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. 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 surface layer 2.

[0076] Functional groups that can react with epoxy groups include those of the same type as those in the follow-up 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 sufficient pot life.

[0077] When the surface layer 2 is composed of an epoxy resin composition, it is particularly preferable that it contains modified NBR having carboxyl groups. Examples of modified NBRs containing carboxyl groups include those similar to those of follow-up layer 3. Two or more modified elastomers having functional groups that can react with epoxy groups may be used in combination.

[0078] The amount of elastomer in the surface 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 surface layer 2. Within this range, the storage modulus can be controlled. If it is below the upper limit, the storage modulus that can press the follow-up layer 3 during thermal bonding can be ensured. Furthermore, flow during thermal curing can be suppressed, preventing post-curing appearance defects such as repulsion, and also minimizing problems when etching is performed in a subsequent process. Furthermore, if it is above the lower limit, the dispersibility of carbon black is improved. In addition, film formation is improved, and the film thickness distribution when coating and forming an epoxy resin composition can be narrowed.

[0079] (Hardening agent) If the surface 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 follow-through layer 3. Two or more other curing agents may be used in combination.

[0080] (curing catalyst) If the surface 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 follow-up layer 3, and preferred embodiments are also similar.

[0081] 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 surface 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.

[0082] (Carbon Black) The surface layer 2 may be colored black, and may contain carbon black for coloring. By including carbon black, light shielding can be achieved between the multiple light-emitting elements of the substrate 10 with the elements, and light diffusion prevention can be obtained. Examples of carbon black include the same type used in follow-up layer 3, and the preferred embodiment is also the same.

[0083] 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 surface layer 2. 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 surface layer 2 increases, reducing its fluidity during thermocompression bonding, and making it impossible to adequately fill the spaces between the multiple light-emitting elements of the substrate 10 with the elements.

[0084] (Other ingredients) The surface layer 2 may contain inorganic fillers for the same reasons as the follow-through layer 3, but it is preferable that it does not contain inorganic fillers other than carbon black for the same reasons as the follow-through layer 3. The surface layer 2 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.

[0085] <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 thermosetting resin composition is applied when forming the dry film 1.

[0086] 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.

[0087] 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.

[0088] <Method for manufacturing dry film> Dry film 1 is obtained by preparing a first carrier film 4 coated with a thermosetting resin composition for the surface layer 2 and dried, and a second carrier film 5 coated with a thermosetting resin composition for the follow-up layer 3 and dried, and then stacking these so that the surface layer 2 and the follow-up layer 3 are in contact, and laminating them.

[0089] 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.

[0090] 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.

[0091] 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 surface layer 2 and the follow-up 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.

[0092] 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.

[0093] <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.

[0094] 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.

[0095] 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.

[0096] <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 follow-up layer is in contact with the multiple light-emitting elements, pressing and pressing it at 90 to 110°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 8.

[0097] In the manufacturing method of this embodiment, first, as shown in Figure 2, a dry film 1, from which the second carrier film 5 has been peeled off to expose the follow-up 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 follow-up layer 3 is in contact with the dry film 1. At this time, that is, before crimping, the thickness of the follow-up layer 3 is preferably 10 to 90% of the height of the light-emitting element. The lower limit is more preferably 15% or more, and even more preferably 30% or more. The upper limit is more preferably 65% ​​or less, and even more preferably 55% or less.

[0098] If the thickness of the follow-up layer 3 is less than 10% of the height of the light-emitting element, the resin will not be sufficiently filled between the light-emitting elements. If the thickness of the follow-up layer 3 is less than 15% of the height of the light-emitting element, the fluidity of the surface layer may be insufficient, and crack-like defects may occur on the surface. If the thickness of the follow-up layer 3 is 30% or more of the height of the light-emitting element, the fluidity of the follow-up layer 3 can be utilized to adequately fill the space between the light-emitting elements with the dry film 1.

[0099] If the thickness of the follow-up layer 3 is 90% or less of the height of the light-emitting element, leakage of the follow-up layer to the outside during thermocompression bonding can be prevented, and the film thickness can be ensured. If the thickness of the follow-up layer 3 exceeds 65% of the height of the light-emitting element, variations in the thickness of the follow-up layer 3 that has flowed after pressing may result in variations in the shade of black. If the thickness of the follow-up layer 3 is 55% or less of the height of the light-emitting element, the fluidity of the follow-up layer 3 can be utilized to appropriately fill the space between the light-emitting elements with the dry film 1.

[0100] The thickness of the surface layer 2 before lamination is preferably 10 to 150% of the height of the light-emitting element. The lower limit is more preferably 40% or more, and even more preferably 50% or more. The upper limit is more preferably 130% or less, and even more preferably 110% or less.

[0101] If the thickness of surface layer 2 is less than 10% of the height of the light-emitting element, it may flow together with the follow-up layer 3 during thermal curing, resulting in surface defects. If the thickness of surface layer 2 is less than 40% of the height of the light-emitting element, the range of flow that can be tolerated for surface layer 2 is insufficient, and crack-like defects may occur on the surface. If the thickness of surface layer 2 is 50% or more of the height of the light-emitting element, the follow-up layer 3 can be sufficiently pressed in. If the thickness of surface layer 2 is equal to the above upper limit relative to the height of the light-emitting element, the subsequent etching process can be shortened.

[0102] The total thickness of the surface layer 2 and the follow-up layer 3 before bonding is preferably 80-200%, 90-160%, and more preferably 100-130% of the height of the light-emitting element. If the combined thickness of the surface layer 2 and the follow-up layer 3 is greater than or equal to the lower limit value relative to the height of the light-emitting element, the dry film 1 can be sufficiently embedded between the light-emitting elements. If the combined thickness of the surface layer 2 and the follow-up layer 3 is less than or equal to the upper limit value relative to the height of the light-emitting element, the subsequent etching process can be shortened.

[0103] The ratio of the thickness of the follow-up layer 3 before crimping to the total thickness of the surface layer 2 and the follow-up layer 3 before crimping is preferably 10-90%, more preferably 15-70%, and even more preferably 20-50%. If the ratio of the thickness of the follow-up layer 3 before bonding to the total thickness of the surface layer 2 and the follow-up layer 3 is equal to or greater than the lower limit, the surface layer 2 can sufficiently press the follow-up layer 3, and the resin can be sufficiently filled between the light-emitting elements. If it is equal to or less than the upper limit, the surface layer 2 will not flow during thermal bonding, suppressing flow during thermal curing, which suppresses defects in the appearance after curing such as streaks, and furthermore, it is less likely to cause problems when etching is performed in a subsequent process.

[0104] 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, the follow-up layer 3 has a relatively low storage modulus and thus maintains fluidity, making it easy to follow the irregularities caused by the light-emitting elements and fill the spaces between them.

[0105] The temperature during thermocompression bonding is 80-120°C, with 90-110°C being more preferable. Setting the temperature to 80°C or higher during thermocompression bonding makes it easier to ensure the fluidity of the dry film 1. Setting the temperature to 120°C or lower during thermocompression bonding makes it less likely to damage the light-emitting element. Setting the temperature to 90-110°C during thermocompression bonding allows for more precise control of fluidity, suppressing the occurrence of unevenness and crack-like defects.

[0106] 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, the dry film 1 can be filled between the light-emitting elements. By setting the pressure below the preferred upper limit, damage to the light-emitting elements 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.

[0107] After pressing, the first carrier film 4 is peeled off as shown in Figure 4, and then heat-cured to form the dry film 1 as the cured product 21, as shown in Figure 5. In Figure 5, the surface layer cured product 22 is the cured product of the surface layer 2, and the follow-up layer cured product 23 is the cured product of the follow-up layer 3.

[0108] 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.

[0109] 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, the surface layer 2 has a relatively high storage modulus and suppressed fluidity, which reduces appearance defects after curing and also minimizes interference when etching is performed in a subsequent process.

[0110] Subsequently, etching is performed as shown in Figure 6, and the surface layer hardened material 22 on the light-emitting element is removed or thinned down to the height of the light-emitting element, as shown in Figure 7. By removing the surface layer hardened material 22 down to the height of the light-emitting element, the brightness of the light-emitting surface can be increased, ensuring visibility when light is emitted. At this time, since it is technically difficult to completely remove the surface layer hardened material 22 from the light-emitting element, it is sufficient if it is substantially removed, and it is acceptable if a small thin film remains. Also, if the surface layer hardened material 22 on the light-emitting element is extremely thin, or if the transmittance of the surface layer hardened material 22 is high and sufficient brightness can be ensured, the etching process can be omitted.

[0111] Etching can be done by physical etching such as plasma treatment or by chemical etching. For example, dry etching can be performed using an anisotropic plasma device with a mixed gas of CF4 / O2 / N2, at an output of 1500-3000W for 180-600 seconds. In this case, the gas supply rate for CF4 should be, for example, 50-100 sccm, the gas supply rate for O2 should be, for example, 500-1000 sccm, and the gas supply rate for N2 should be, for example, 50-100 sccm.

[0112] Finally, as shown in Figure 8, 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. Furthermore, if the transparency of the surface layer cured material 22 is ensured, the surface layer cured material 22 on the light-emitting element may be used as a sealing material without being removed. [Examples]

[0113] 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.

[0114] <Raw materials> The details of the raw materials used in each example and comparative example are as follows. [Epoxy resin] 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.

[0115] [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.

[0116] [resin] • HF-1M: HF-1M manufactured by Meiwa Kasei Co., Ltd., a phenol novolac resin.

[0117] [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.

[0118] [Carbon Black] • Special Black 4: Gas black manufactured by ORION ENGINEERED CARBONS.

[0119] [Additives] • KBM-403: Epoxysilane coupling agent manufactured by Shin-Etsu Silicone Co., Ltd.

[0120] [solvent] • MEK: Methyl ethyl ketone, manufactured by Junsei Chemicals. PGM: Propylene glycol monomethyl ether, manufactured by Junsei Chemicals.

[0121] <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 to prepare a coating solution with a solids concentration of 25% by mass. That is, the total amount of the raw materials in the formulations shown in Table 1 (on a solids basis) was set to 25% by mass of the total amount of the resulting coating solution.

[0122] <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.

[0123] The storage modulus of the coating film on the obtained single-layer sheets 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.

[0124] [Table 1]

[0125] <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 the surface layer, in which the surface layer was supported by the release PET, and a single-layer sheet for the follow-up layer, in which the follow-up layer was supported by the release PET. Each single-layer sheet was stacked so that the surface layer and the follow-up layer were in contact, and laminated using a roll laminator at 60°C to create a dry film laminate in which the release PET, surface layer, follow-up layer, and release PET were sequentially layered.

[0126] <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.

[0127] <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.

[0128] <Evaluation of the dry film in the example> The release PET in contact with the follow-up layer of the dry film laminate was peeled off, and the follow-up 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, 100°C, 0.36 MPa, and 3 minutes. After peeling off the release PET in contact with the surface layer, the film was heat-cured by heating in a 150°C oven for 1 hour.

[0129] [Followability] The surface of the dry film filled using a vacuum press was observed and evaluated according to the following criteria. The results are shown in Table 2. ◎: Only a small amount of resin remains on top of the LED light-emitting element. ○: Resin is visible on top of the LED light-emitting element. △: A large amount of resin is visible on top of the LED light-emitting element. ×: The resin on top of the LED light-emitting element remains as a film and has not deformed.

[0130] [Air bubble-like defects] The hardened surface was observed and evaluated according to the following criteria. The results are shown in Table 2. ○: No defects such as air bubbles or blemishes are observed. △: A small amount of bubble-like defects are visible. ×: There are defects such as repulsion due to the flow of the resin.

[0131] [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.

[0132] <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, 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 of the dry film filled using a vacuum press was observed and its conformability was evaluated. Also, similar to the examples, the surface after curing was observed and bubbly defects and crack-like defects were evaluated. The results are shown in Table 2.

[0133] [Table 2]

[0134] As shown in Table 2, the two-layer dry film according to the present invention exhibited excellent conformability and showed no bubble-like defects after curing. In contrast, the single-layer dry film of the comparative example either did not have sufficient conformability or showed defects such as bubble-like or repellent properties after curing. [Explanation of Symbols]

[0135] 1 Dry film 2 Surface layer 3. Follower 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 Surface layer cured product 23. Cured follow-up layer 30 Light-emitting electronic components 31. Sealing material

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 follow-up layer positioned in contact with the element-equipped substrate during the aforementioned crimping process, and a surface layer laminated on the side of the follow-up layer opposite to the element-equipped substrate. The storage modulus of the surface layer is greater than the storage modulus of the follow-up layer, A dry film characterized in that the ratio of the thickness of the follow-up layer before lamination to the total thickness of the surface layer and the follow-up layer before lamination is 20 to 50%.

2. The dry film according to claim 1, wherein at 100°C, the storage modulus of the surface layer is greater than the storage modulus of the follow-up layer, and at 150°C, the storage modulus of the surface layer is greater than the storage modulus of the follow-up layer.

3. The storage modulus of the aforementioned follow-up layer is 1.0 × 10 at 100°C. ５ A dry film according to claim 1 or 2, wherein the pressure is Pa or less.

4. The storage modulus of the surface layer is 1.0 × 10 at 100°C. ７ A dry film according to claim 1 or 2, wherein the pressure is Pa or less.

5. The dry film according to claim 1 or 2, wherein at least one of the following layer and the surface layer comprises an epoxy resin.

6. The dry film according to claim 5, wherein at least one of the following layer and the surface layer comprises a modified elastomer having a functional group that can react with epoxy groups.

7. The dry film according to claim 1 or 2, wherein at least the following layer contains carbon black.

8. 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.

9. On the surface of the element-equipped substrate on which the plurality of light-emitting elements are arranged, the dry film according to claim 1 or 2 is placed so that the following layer is in contact with it. 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.

10. The thickness of the following layer before crimping is 10 to 90% of the height of the light-emitting element. The method for manufacturing a light-emitting electronic component according to claim 9, wherein the total thickness of the following layer and the surface layer before bonding is 80 to 200% of the height of the light-emitting element.

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