Composition for manufacturing anisotropic conductive film

Abstract

A composition for manufacturing an anisotropic conductive film, according to the present invention, the composition being hardened to be an electrically bonding material for coupling one electrode and the other electrode of an electronic component and comprising: a metal precursor including a metal ion that provides electrical conductivity to the bonding material; a curable resin containing a curable polymer; a phase separation inducing agent for inducing phase separation between the metal reduced from the metal ion and the polymer; and a solvent.

Description

Composition for manufacturing anisotropic conductive film

[0001] The present invention relates to a composition for manufacturing an anisotropic conductive film, an anisotropic conductive film, an anisotropic conductive connection method, and an anisotropic conductive connection structure, and more particularly, to a composition for manufacturing an anisotropic conductive film, an anisotropic conductive film, an anisotropic conductive connection method, and an anisotropic conductive connection structure for bonding and electrically connecting an electrode of a substrate and an electrode of a chip.

[0002] Anisotropic conductive films are used in a variety of applications in the manufacture and assembly of semiconductor packages and microelectronic devices. For example, they are used as electrical interconnect films for bonding integrated circuit chips to substrates, or as interconnect films for bonding circuit assemblies to printed circuit boards.

[0003] More specifically, the anisotropic conductive film (ACP) can be used for bonding formation of various electronic hardware, including chip-on glass assembly (COG assembly), flip chip on flex assembly, contactless smart card module assembly, and film chip die attach on a flexible substrate or rigid substrate.

[0004] Recently, micro LED (Light-emitting diode), also called micro light-emitting diode, refers to an ultra-small LED with a side size of less than 100㎛, and is one of the important technologies for implementing flat panel display technology.

[0005] Micro LEDs offer superior energy efficiency and optical efficiency compared to conventional LEDs, along with low heat generation per unit area. They also enable the creation of extremely small pixels, making them highly promising for applications beyond lighting, such as ultra-small displays and precision medical devices. Anisotropic conductive films (ACFs) are used to attach these micro LEDs to electrodes on a substrate.

[0006] Because the size of the micro LED used in 4K (3840 * 2160) flat panel displays was at least 50 * 20㎛, a bonding process using ACF to attach electrodes was possible. However, to implement high-definition resolutions of 8K or higher, the size of the micro LED must be further reduced to 30 * 20㎛.

[0007] Therefore, when used for electrical bonding of micro devices such as micro LEDs, the conductive particles used in conventional ACFs are very large, with diameters ranging from about 3 to 10 μm, making bonding small micro LED chips technically problematic. In other words, for micro LED chips intended for high-definition display, the spacing between electrodes is less than 30 μm (or pitch), making bonding using an ACF film very difficult.

[0008]

[0009] The first aspect of the present invention is to overcome the above-mentioned problem, and provides a composition for manufacturing an anisotropic conductive film that is capable of bonding even at a fine pitch of 30 μm or less, and has an anisotropic conductive property, that is, electricity is not conducted in the X and Y axes, but only in the Z axis, and does not contain conductive particles.

[0010] The second and third aspects of the present invention are proposed to overcome the above-mentioned problems, and provide an anisotropic conductive film having a sintered body in which metal particles are reduced in an electrically connecting direction using the composition for manufacturing an anisotropic conductive film described above.

[0011] The fourth aspect of the present invention is to overcome the aforementioned problems and to provide an anisotropic connection structure having a sintered body in which metal particles are reduced in an electrically connecting direction using the anisotropic conductive film described above.

[0012] The first aspect of the present invention is a composition for manufacturing an anisotropic conductive material that electrically connects opposing first and second electrodes,

[0013] A metal precursor comprising a metal ion that provides electrical conductivity to the above anisotropic conductive material;

[0014] A curable resin comprising a curable polymer;

[0015] A phase separation inducing agent that induces phase separation between a metal reduced from the metal ion and the curable resin;

[0016] A flow control agent that shortens the curing time and controls flowability; and

[0017] A composition for manufacturing an anisotropic conductive material comprising a solvent.

[0018] The purpose of the above phase separation inducing agent is to provide a composition for manufacturing an anisotropic conductive material including a hydrophilic group and a lipophilic group.

[0019] At this time, it is preferable that the number of carbon atoms in the lipophilic group is 5 to 25, and the hydrophilic group includes a carboxyl group (-COOH) or an amine group (- NH).

[0020] In addition, it is preferable that the compound containing the carboxyl group is at least one selected from the group consisting of caprylic acid, pelargonic acid, caproic acid, undecanic acid, lauric acid, myristic acid, behenic acid, palmitic acid, lignoceric acid, stearic acid, eicosanoic acid, and oleic acid, or a combination thereof.

[0021] In addition, it is preferable that the compound containing the amine group is at least one selected from the group consisting of hexylamine, heptylamine, octylamine, oleylamine, decylamine, dodecylamine, 2-ethylhexylamine, and 1,3-dimethyl-n-butylamine, or a combination thereof.

[0022] In addition, the composition can be cured to a certain level and formed into a film when first heated at 60 to 100°C.

[0023] In addition, when the composition is heated and becomes a cured product between the first electrode and the second electrode, it is preferable that a conductive path is formed in the Z-axis direction, which is the opposite direction, and that no conductive path is formed in the X-axis and Y-axis directions, which are each perpendicular to the Z-axis direction.

[0024] In addition, it is preferable that the above-mentioned hardened material is formed by reducing the metal ions and a plurality of sintered bodies grow in the Z-axis direction to electrically connect the first electrode and the second electrode.

[0025] In addition, it is preferable that the plurality of sintered bodies in the above-mentioned hardened product are not connected to each other in the X and Y-axis directions.

[0026] In addition, it is preferable that the curable resin is a polymer resin that can be polymerized by radicals.

[0027] Additionally, the curable resin may be an epoxy resin or an acrylic resin.

[0028] In addition, the curing agent is a substance that cures the curable resin with heat or light, and preferably includes an amine or phosphine compound.

[0029] In addition, it is preferable that the amine compound is composed of a substance selected from the group consisting of 2-methyl imidazole, 2,4-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole; and triethylamine, benzyldimethylamine, methylbenzyldimethylamine, 2-(dimethylaminomethyl)phenol, and 2,4,6-tris(dimethylaminomethyl)phenol as a tertiary amine compound.

[0030] In addition, the above phosphine compound,

[0031] Triethylphosphine, tributylphosphine, 1,8-diazabicyclo(5,4,0)undecene-7; or preferably one selected from the group consisting of triphenylphosphine, trimethylphosphine, triethylphosphine, tributylphosphine, tri(p-methylphenyl)phosphine (Tris(4-methoxyphenyl)phosphine), and tri(nonylphenyl)phosphine as organic phosphine compounds.

[0032] In addition, it is preferable that the flow control agent is an acrylic polymer resin having a molecular weight of 10,000 to 1,100,000.

[0033] In addition, it is preferable that the flow control agent has a glass transition temperature (Tg) of -20 to 110°C.

[0034] In addition, for 60 parts by weight of the metal precursor, it is preferable that the phase separation inducer is included in an amount of 5 to 15 parts by weight, the curable resin is included in an amount of 3 to 8 parts by weight, the curing agent is included in an amount of 3 to 8 parts by weight, and the solvent is included in an amount of 15 to 25 parts by weight.

[0035] In addition, it is preferable that the composition further includes nanoparticles in an amount of 5 to 15 parts by weight per 60 parts by weight of the metal conductive precursor.

[0036] In addition, it is preferable that the nanoparticles include one selected from the group consisting of silver (Ag), gold (Au), indium (In), copper (Cu), indium tin oxide (ITO), palladium, platinum, nickel, and iridium.

[0037] The present invention also

[0038] A metal precursor comprising a metal ion that provides electrical conductivity;

[0039] A curable resin comprising a curable polymer;

[0040] A phase separation inducing agent that induces phase separation between the metal reduced from the metal ion and the curable resin; and

[0041] An anisotropic conductive material is provided, which includes a flow control agent that shortens the curing time and controls flowability.

[0042] At this time, the anisotropic conductive material is partially cured by the first heating at 60 to 100°C and is thus freestanding.

[0043] In addition, it is preferable that the anisotropic conductive material is formed into a sintered body in which the metal ions are reduced by a second heating after the first heating by heat or light and grow to form a conductive path in one direction.

[0044] Additionally, the above-mentioned conductive material may be a film that electrically connects the opposing first electrode and the second electrode.

[0045] The composition for manufacturing an anisotropic conductive film according to the present invention does not contain metal particles therein and can be applied to microelectrodes, so that even when applied between electrodes, electricity does not flow in the x and y directions but only in the z direction (i.e., between the electrodes of the substrate and the electrodes of the chip), thereby having the effect of allowing electricity to flow in a desired direction without causing a short circuit between the electrodes.

[0046] The anisotropic conductive film according to the present invention comprises a sintered body that is electrically conductive in only one direction, utilizing a metallic component that is reduced and sintered by light or heat. Therefore, even when installed across adjacent electrodes, short circuits between the electrodes do not occur in the other direction, effectively enabling efficient anisotropic conductive connection between microelectrodes.

[0047] Accordingly, the present invention can be applied to various connection structures requiring various anisotropic conductive electrical connections. In particular, it can be preferably applied to connections of micro LEDs, chip on glass (COG), chip on film (COF), film on board (FOB) of flat panel displays (FPDs), and connector replacement connections (connections between rigid substrates and film materials, and between film materials).

[0048] Fig. 1 (a) is a conceptual diagram explaining a connection structure according to the present embodiment.

[0049] Fig. 1 (b) is a conceptual diagram illustrating a connection structure according to another embodiment of the present invention.

[0050] FIG. 2 is a schematic diagram explaining a mechanism in which a region where a sintered body is located and a region where a polymer is located are hybridized with each other and have an anisotropic structure according to the reduction and sintering of metal particles and hardening of a curable resin during heat or laser curing according to the present embodiment.

[0051] Figure 3 is an experimental photograph showing the resistance measurement of an anisotropic conductive film manufactured with the composition of Example 1.

[0052] Figure 4 is a photograph showing the resistance measurement location.

[0053] Figure 5 is a resistance graph between an ITO substrate and a COF film.

[0054] Figure 6 is a resistance graph between a glass substrate and a COF film.

[0055] Figure 7 is an experimental photograph showing the resistance measurement between the electrode and the conductive substrate after thermal curing of the anisotropic conductive film manufactured with the composition of Example 2.

[0056] Figure 8 is an experimental photograph showing the resistance measurement between the electrode and the insulating substrate after thermal curing of the anisotropic conductive film manufactured with the composition of Example 2.

[0057] Figure 9 is a cross-sectional view of a laser curing device.

[0058] Figure 10 is an electron microscope photograph of the bonding material portion taken with an electron microscope after bonding the electrodes in Experimental Example 3.

[0059] Figure 11 is an EDS analysis photograph of a sintered body formed between electrodes in Experimental Example 3.

[0060] Figure 12 is a process diagram illustrating a process of attaching a micro LED electrode to a micro LED substrate using an anisotropic conductive film.

[0061] Figure 13 is an experimental photograph showing the lighting of a micro LED.

[0062] Figures 14 and 15 are electron microscope photographs of the area where the anisotropic conductive film is cured and connects the electrodes.

[0063] Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings. However, the spirit of the present invention is not limited to the presented embodiments, and those skilled in the art who understand the spirit of the present invention will be able to easily propose other regressive inventions or other embodiments included within the spirit of the present invention by adding, modifying, or deleting other components within the scope of the same spirit. However, this will also be considered to be included within the spirit of the present invention.

[0064] In addition, components having the same function within the same scope of the same idea shown in the drawings of the embodiment are described using the same reference numerals.

[0065] Hereinafter, the present invention will be described in more detail with reference to the drawings.

[0066] <Aspect 1>

[0067] Example A of a composition for manufacturing an anisotropic conductive material according to the first aspect of the present invention includes a metal precursor, a phase separation inducer, a curable resin, curing agents for curing the curable resin, a flow control agent, and a solvent.

[0068] The metal precursor is a material in a state before being reduced to a metal filler having conductivity in an anisotropic conductive composition. The metal precursor may be a compound including a metal hydride, a metal hydroxide, a metal sulfur oxide, a metal nitrate, a metal halide, a metal complex compound, or a combination thereof.

[0069] At this time, the metal precursor may include one or more metals or alloys thereof having high electrical conductivity, such as silver (Ag), copper (Cu), gold (Au), bismuth, indium, palladium, platinum, nickel, and iridium. Preferably, it includes silver (Ag), which is easily reduced, has high electrical conductivity after reduction, and is stable.

[0070] In addition, the anions for forming the metal precursor are hydroxide ion, carboxylic ion, acetate ion, propionate ion, acetylacetonate ion, 2,2,6,6-tetramethyl-3,5-heptanedionate ion, methoxide ion, sec-butoxide ion, t-butoxide ion, n-propoxide ion, i-propoxide ion, ethoxide ion, phosphate ion, alkylphosphonate ion, nitrate ion, perchlorate ion, sulfate ion, It is preferable to include an anion that is at least one selected from the group consisting of alkylsulfonate ion, phenoxide ion, bromide ion, iodide ion, and chloride ion, or a combination thereof.

[0071] A phase-separation inducer is a substance that induces phase separation between the reducing metal and the curing polymer. It is a substance that causes phase separation between the reduced metal and the curing polymer when the metal precursor is reduced by heat or light (laser), as described later. In other words, the metal ions in the metal precursor state are reduced and sintered, and at this time, they phase-separate from the polymer.

[0072] It is presumed that the phase separation inducer contains both hydrophilic and lipophilic groups within its molecule, so that the hydrophilic groups surround the reduced conductive metal particle mass (hereinafter referred to as a sintered body) on the surface, and the lipophilic groups induce phase separation by coming into contact with the polymer.

[0073] At this time, it is preferable that the number of carbon atoms in the lipophilic group is 5 to 25, and the hydrophilic group includes a carboxyl group (-COOH) or an amine group (- NH).

[0074] Specifically, the phase separation inducer is a compound containing a carboxyl group, and at least one fatty acid selected from the group consisting of caprylic acid, pelargonic acid, caproic acid, undecanic acid, lauric acid, myristic acid, behenic acid, palmitic acid, lignoceric acid, stearic acid, eicosanoic acid, and oleic acid, or a combination thereof, may be used.

[0075] Among the phase separation inducers, compounds containing amines may be selected from the group consisting of, for example, hexylamine, heptylamine, octylamine, oleylamine, decylamine, dodecylamine, 2-ethylhexylamine, and 1,3-dimethyl-n-butylamine, at least one or a combination thereof may be used.

[0076] At this time, the phase separation inducer induces phase separation by surrounding the conductive metal particle mass (hereinafter referred to as a sintered body) on the surface with the hydrophilic group, carboxyl group or amine group, and by contacting the polymer with the lipophilic group, alkyl group.

[0077] When an anisotropic conductive composition is heated by heat or laser while the metal and polymer are phase-separated to form a cured product, the cured product forms multiple sintered bodies through reduction of metal ions. The metal sintered bodies are rich in metal and thus electrically conductive. In addition, the area outside the sintered body does not have electrical conductivity as the curable resin is formed into a hardened polymer.

[0078] At this time, the cured product is formed by reducing metal ions, and a plurality of sintered bodies grow in the Z-axis direction to electrically connect the first electrode and the second electrode, and the plurality of sintered bodies are not connected to each other in the X and Y-axis directions.

[0079] By this phase separation induction method, conductive paths are not formed in the X and Y axes, and only the Z-axis direction becomes a conductive path through which electricity can flow. At this time, the Z-axis is, for example, the direction in which the first electrode and the second electrode face each other, and the X and Y-axis directions are directions perpendicular to the Z-axis direction.

[0080] The curable resin is a polymer resin that can be polymerized by radicals, and a resin such as an epoxy resin can be used. Examples of epoxy resins that can be used include bisphenol A type epoxy resin, substituted epoxy resin, linear aliphatic epoxy resin, cresol novolac type epoxy resin, biphenyl type epoxy resin, heterocyclic epoxy resin, and halogenated epoxy resin, all of which contain two or more epoxy groups per molecule. In addition, two or more types of the above-mentioned epoxy resins can be used in combination.

[0081] In addition, an acrylic resin may be used as the curable resin, and at this time, as a monomer for curing, (meth)acrylate is a monomer or oligomer having one or more functional groups, and one or two or more selected from urethane acrylate, epoxy acrylate, cresol novolac acrylate, phenol novolac acrylate, phosphoric acid acrylate, etc. having one or more reactive functional groups and less than 20 may be used.

[0082] Preferred examples of acrylate monomers include neopentylglycol mono(meth)acrylate, 1,6-hexanediol mono(meth)acrylate, pentaerythritol penta(meth)acrylate, dipentaerythritolpenta(meth)acrylate, glycerin di(meth)acrylate, tetrahydrofurfuryl(meth)acrylate, isodecyl(meth)acrylate, 2-(2-ethoxyethoxy)ethyl(meth)acrylate, stearyl(meth)acrylate, lauryl(meth)acrylate, 2-phenoxyethyl(meth)acrylate, isobornyl(meth)acrylate, It is selected from the group consisting of tridecyl (meth)acrylate, ethoxylated nonylphenolacrylate, ethylene glycol di(meth)acrylate, ethoxylated bisphenol-AD(meth)acrylate, cyclohexanedimethanol di(meth)acrylate, phenoxy tetraethylene glycol (meth)acrylate, 2-methacryloyloxyethyl phosphate, 2-methacryloyloxyethyl phosphate, dimethylol tricyclodecane di(meth)acrylate, dipentaerythritol hexaacrylate, trimethylopropanebenzoate acrylate, and mixtures thereof. The content of the (meth)acrylate monomer is preferably about 5 to 50 wt%.

[0083] A curing agent is a substance that cures a curable resin with heat or light, and one or more amine or phosphine compounds can be used. For example, amine curing agents include 2-methyl imidazole, 2,4-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, and 2-phenyl-4-methylimidazole; and tertiary amine compounds include triethylamine, benzyldimethylamine, methylbenzyldimethylamine, 2-(dimethylaminomethyl)phenol, and 2,4,6-tris(dimethylaminomethyl)phenol.

[0084] Additionally, phosphine compounds may be used, such as triethylphosphine, tributylphosphine, 1,8-diazabicyclo(5,4,0)undecene-7; or organic phosphine compounds may be used, such as triphenylphosphine, trimethylphosphine, triethylphosphine, tributylphosphine, tri(p-methylphenyl)phosphine (Tris(4-methoxyphenyl)phosphine), and tri(nonylphenyl)phosphine.

[0085] The curing agent for curing the acrylic resin is a substance that cures the curable resin with heat or light, and is preferably an oil-soluble curing agent or a redox curing agent such as an organic peroxide such as lauryl peroxide, benzoyl peroxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide, or t-butyl hydroperoxide.

[0086] The flow control agent is a component included to control the flow of the conductive material and to cure the composition very quickly. The acrylic polymer resin having a molecular weight of 10,000 to 1,100,000 and a glass transition temperature (Tg) of -20 to 110°C is preferable, and the acrylic polymer resin containing methacrylic is preferable.

[0087] When manufacturing a conductive material as a freestanding conductive material (e.g., film), if the molecular weight is less than 10,000, it is difficult to manufacture it by forming a film during the first heating, and when pressing during the second heating, it flows too easily due to the high temperature and high pressure, so the resin comes out too easily, resulting in high resistance and greatly reduced adhesive strength. If the molecular weight is more than 1,100,000, the film becomes too brittle and breaks easily, and the tackiness (stickiness) is too low, so the film and COF, TCP, etc. do not stick together during pressing, increasing the probability of defects.

[0088] At this time, the first heating refers to heating that enables free-standing curing from the composition and does not reduce the internal metal ions, and the second heating refers to heating that reduces the internal metal ions to form a sintered body.

[0089] In addition, when the aforementioned flow control agent is connected to the electrode of a COF (chip on flexible printed circuit) and the ITO or Ti / Al / Ti electrode section, it has an initial electrical connection resistance value that cannot be obtained with a conventional ACF and a high Tg of the acrylic rubber itself, so it is possible to obtain sufficient connection reliability by having heat and moisture resistance.

[0090] The solvent is for dissolving the above-mentioned components, and the solvent may be used without limitation, but may include tetrahydrofuran (THF), alcohol solvents, ether solvents, sulfide solvents, toluene solvents, xylene solvents, benzene solvents, alkane solvents, oxane solvents, amine solvents, polyol solvents, or diketone, amino alcohol, polyamine, ethanol amine, diethylnol amine, ethane thiol, propane thiol, butane thiol, pentane thiol, hexane thiol, heptane thiol, It is preferable to use a solvent comprising at least one selected from the group consisting of octane thiol, nonane thiol, decane thiol, and undecane thiol, or a combination thereof.

[0091] In the aforementioned composition, it is preferable that the metal precursor is included in an amount of 30 parts by weight, the flow control agent in an amount of 25 to 35 parts by weight, the phase separation inducer in an amount of 5 to 15 parts by weight, the curable resin in an amount of 8 to 15 parts by weight, the curing agent in an amount of 3 to 8 parts by weight, and the solvent in an amount of 15 to 25 parts by weight.

[0092] If the phase separation inducer exceeds the above range compared to the metal precursor, there is a problem of increased electrical resistance, and if it is below the above range, there is a problem of no phase separation induction.

[0093] Additionally, if the amount of curable resin used is less than the range, there is a possibility of poor adhesion, and if the amount of curable resin used exceeds the range, there is a problem of increased electrical resistance between the micro LED and the substrate electrode.

[0094] In addition, if the amount of the hardener is less than the range, poor adhesion may occur due to insufficient curing of the curable resin, and if the amount is more than the range, the curing speed of the curable resin may become too fast, making it difficult to obtain sufficient electrical conductivity, or the composition may become cured before transfer is performed.

[0095] Therefore, within the aforementioned range, the composition may have a 5B adhesion test scale according to the ISO 2409, a continuous printability of >7 days, and a laser curing characteristic that is ultra-fast curing of 30 seconds or less, preferably 10 seconds or less, upon laser curing.

[0096] Meanwhile, when curing the composition with a laser, a wavelength of 760 nm to 4900 nm can be used, and IR with a wavelength of 1000 nm to 4900 nm is particularly preferred. This is because if the wavelength is outside the above range, damage to electronic components may occur during laser curing.

[0097] Even when reducing and sintering metal precursors with a laser, both materials that cure with heat or light can be cured with the curable resin. Even with laser curing, heat-curable resins are possible because the laser generates heat in the electrode, which in turn provides the heat necessary for curing the curable resin.

[0098] In this aspect, the composition for manufacturing an anisotropic conductive film is sintered by a mechanism as shown in Equation 1 below, and a sintered body in which a metal precursor is reduced is formed, thereby having conductivity even without conductive particles.

[0099] (Formula 1)

[0100]

[0101] In the above description, the number of electrodes has been limited for convenience of explanation, but those skilled in the art will recognize that the same can be applied to a connection structure composed of N lower electrodes and N upper electrodes facing them.

[0102] Embodiment B of the anisotropic conductive composition according to the first aspect of the present invention comprises a metal precursor, a phase separation inducer, a curable resin, curing agents for curing the curable resin, a flow control agent, a solvent, and conductive particles.

[0103] That is, compared to Example A, Example B additionally includes conductive particles. The conductive particles may be selected from the group consisting of silver (Ag), gold (Au), indium (In), copper (Cu), indium tin oxide (ITO), palladium, platinum, nickel, and iridium, and nanoparticles having a size in the range of 0.01 to 5.0 μm may be used.

[0104] It is preferable that the conductive particles be included in an amount of 5 to 15 parts by weight per 60 parts by weight of the metal conductive precursor. Thus, by adding a small amount of the conductive particles, the electrical conductivity can be further improved in addition to the electrically conductive sintered body.

[0105] Conductive materials that can be manufactured using a composition for manufacturing anisotropic conductive materials may include anisotropic conductive films (ACF), anisotropic conductive tapes (ACT), anisotropic conductive adhesives (ACA), anisotropic conductive pastes (ACP), etc.

[0106] <Second Aspect>

[0107] A second aspect of the present invention is a method for manufacturing an anisotropic conductive film. The manufacturing of an anisotropic conductive film includes a release film providing step, a composition application step, and a heating step.

[0108] The release film provision step is a step of providing a release film that enables the applied composition to be easily peeled off and formed into a film. The release film is not limited in type as long as it is a conventional film used in the art, and for example, PET film can be used.

[0109] The composition application step is a step of applying the composition of the first side to the release film in a desired size. The thickness of the coating film during application is 30 to 200 um, preferably 40 to 150 um.

[0110] The above composition includes a metal precursor, a phase separation inducer, a curable resin, curing agents for curing the curable resin, a flow control agent, and a solvent.

[0111] When applied, the metal precursor is dissolved in a liquid in the form of a metal salt, but is reduced by heat or light between the electrodes, functioning as a conductive metal. At this time, the reduced conductive metal forms a particle mass (hereinafter referred to as a sintered body) and acquires metallic conductivity. In the anisotropic conductive film state before heating between the electrodes, the metal precursor is not reduced.

[0112] When the phase separation inducer is cured by heat or light, it causes the curable resin and the reducing metal precursor to phase separate from each other, so that the areas where each metal and resin are located are distinct in the applied state.

[0113] At this time, the reduced metal within the applied film forms at least one sintered body, and when the polymer region in which the curable resin is distributed is called a polymer region, the sintered body is distributed in a region distinct from the polymer region, so that the sintered body and the curable resin are separated.

[0114] The curable resin and curing agent are resins suitable for general heat curing or photocuring, and are cured while forming a polymer region that is separated from the metal by a phase separation inducer during heat or photocuring.

[0115] The flow control agent is a component included to control the flowability for rapid curing of the composition and film formation, and is preferably an acrylic polymer resin having a molecular weight of 10,000 to 1,100,000, a glass transition temperature (Tg) of -20 to 110°C, and containing methacrylic.

[0116] The solvent is a substance that dissolves the resin, and the viscosity of the composition after dissolution is preferably 5 to 10,000 cP at 25°C, more preferably 10 to 2,000 cP.

[0117] In the composition application step, the composition may be applied using one method selected from the group consisting of screen printing, inkjet, doctor blade, slot die, dispenser, eHD printing, spin coating, and pad printing, depending on the intended use of the application product. A description of each method is as follows.

[0118] Screen printing is a printing method that transfers ink to a substrate through a specially designed mesh screen, and has the advantage of being able to print thick paints on various substrates.

[0119] Inkjet printing is a digital printing method that sprays fine ink droplets onto a substrate through a nozzle. It has high resolution and fast production speed, and is also used for flexible substrates and semiconductor devices.

[0120] A doctor blade is a sharp-edged tool used in the screen printing process to evenly spread ink and remove excess, improving the quality of electronic printing by increasing ink thickness and consistency.

[0121] Slot die is a method of coating a substrate with paint or adhesive at a constant thickness. It is used in the manufacture of electronic components and elements due to its precise thickness control and high production efficiency.

[0122] A dispenser is a device that precisely places a small amount of ink, adhesive, or paint on a substrate, and is used for various electronic printing tasks such as bonding electronic components and placing elements.

[0123] eHD printing is a technology that uses electric fields to enable high-precision and high-resolution printing, and is used for fine electronic components and organic light-emitting diode (OLED) displays.

[0124] Spin coating is a process of forming a coating of a certain thickness by dropping a liquid or gel-like material onto a high-speed rotating substrate. It is used in various electronic devices and semiconductor processes to create an even, thin coating.

[0125] Pad printing is a printing technology that uses a soft silicone pad to transfer ink from a printing plate to a substrate with a complex shape or surface. It can also print on electronic components with curved or irregular surfaces, and is used in the manufacture of various electronic products.

[0126] The heating step is the first heating step described above, and is a step of applying heat to the coating film applied in the composition application step. By applying heat to the coating film, the applied composition hardens to a certain extent and can be peeled off as a film. The heating temperature is preferably 60 to 100°C. At the above heating temperature, which is an appropriate temperature for film formation, the metal precursor in the coating film applied in this heating step does not reduce to a sintered body, and the applied composition has free-standing properties.

[0127] In another embodiment of the second aspect of the present invention, the manufacturing of an anisotropic conductive film may additionally include a heating step. The peeling step is a step of forming an anisotropic conductive film by peeling the coating from the release film. The anisotropic conductive film manufactured in the peeling step is still in an unsintered state in the metal precursor within the heating step, and when the metal precursor is later placed between electrodes and a laser or heat is applied, the metal precursor is reduced and sintered, thereby conducting electricity in one direction.

[0128] <Third Aspect>

[0129] The connecting material that is separated after the peeling step becomes an anisotropic conductive film that conducts electricity in only one direction.

[0130] An anisotropic conductive film manufactured according to the present invention is manufactured from a composition including a metal precursor capable of forming a sintered body having conductivity by being reduced by heat or laser while forming a film by a flow control agent, a phase separation inducer, a curable resin, and curing agents for curing the curable resin.

[0131] Accordingly, when the anisotropic conductive film is subjected to a second heating temperature higher than the first heating temperature applied during the manufacturing process of the anisotropic conductive film of the second aspect described above after being manufactured, the metal ions inside are reduced to become metal particles, and the metal particles are sintered to form a sintered body.

[0132] The second heating is preferably between 100 and 300°C. Below the above range, it is difficult to form a sintered body, and above the above range, the process temperature is high, causing problems such as heat damage to the substrate or base material.

[0133] At this time, the sintered body grows in one direction, and the area around the sintered body is a region where the polymer is hardened, so a conductive path is formed through which electricity can only move in the direction in which the sintered body grows.

[0134] That is, when the anisotropic conductive film is hardened by the second heating while being inserted between the first electrode and the second electrode of the electronic component, a conductive path is formed by the sintered body in the Z-axis direction, which is the direction in which the first and second electrodes face each other, and electricity flows, but no conductive path is formed in the X and Y-axis directions, which are perpendicular to the Z-axis direction.

[0135] At this time, the anisotropic conductive film may further include nanoparticles in an amount of 5 to 15 parts by weight per 60 parts by weight of the metal precursor.

[0136] It is preferable that the nanoparticles be one selected from the group consisting of silver (Ag), gold (Au), indium (In), copper (Cu), indium tin oxide (ITO), palladium, platinum, nickel, and iridium, or an alloy thereof.

[0137] Additionally, it is preferable that the nanoparticles be 0.01 to 5.0 μm.

[0138] <Aspect 4>

[0139] A fourth aspect of the present invention is a connection structure using an anisotropic conductive film.

[0140] FIG. 1 (a) is a conceptual diagram illustrating a connection structure according to the present embodiment, and the connection structure according to the present embodiment includes a first electrode (20), a second electrode (30), and a connection material (70) that electrically connects the first electrode (20) and the second electrode (30).

[0141] The first electrode (20) is an electrode for electrical connection formed on a device or a flexible substrate, and the material of the electrode is not limited, but can be used as a transparent electrode, an opaque electrode, etc., and can be used as an ITO electrode, a Ti / AL / Ti electrode, for example.

[0142] The second electrode (30) is an electrode for electrical connection with the first electrode (20), and may be, for example, a substrate having a fine-pitch wiring electrode or a backplane substrate for attaching the electrode of a micro LED chip. The second electrode (30) is provided at a position facing the first electrode (20), and may be an electrode having a laminated structure of copper, gold (Au), or molybdenum-aluminum-molybdenum.

[0143] At this time, the first electrode (20) and the second electrode (30) are respectively opposed, and the gap between the first electrode (20) and the second electrode (30) is preferably 10 nm to 10 μm, preferably 10 nm to 1000 nm, preferably 100 to 450 nm, and more preferably 140 to 440 nm. If the gap exceeds the above range, there is a problem that the contact resistance increases. At this time, the width of each electrode is 1 to 1000 μm, preferably 3 to 80 μm.

[0144] The connecting material (70) is a material for electrically connecting the first electrode (20) and the second electrode (30), and is an anisotropic conductive connecting material that allows electricity to flow only in the connection direction of the first electrode (20) and the second electrode (30) and does not allow electricity to flow in a direction other than the connection direction of the first electrode (20) and the second electrode (30).

[0145] At this time, the connecting material is positioned between the first electrode (20) and the second electrode (30) to physically and electrically connect them, and when cured, the anisotropic conductive composition film placed between the first electrode (20) and the second electrode (30) is cured and formed while being heated and pressed.

[0146] An anisotropic conductive film is a film manufactured from a composition including a metal precursor, a phase separation inducer, a curable resin, a curing agent, a curable resin, a flow control agent, and a solvent for dissolving the curing agent.

[0147] An anisotropic conductive film between the first and second electrodes has a structure in which a sintered body, in which metal ions derived from a metal precursor are reduced when cured by laser or heat to form a conductive path that electrically connects the first and second electrodes, is separated from a polymer region where a polymer formed by curing a curable resin is located. In this case, the region where the sintered body is located and the region where the polymer is located are hybridized in multiple ways.

[0148] That is, the metal precursor exists as a metal ion in the ink state, and in the process of reducing the metal ion of the precursor by heat or laser, the metal is reduced to a metal on the surface of the electrode portion of the chip and substrate, forming a seed layer. Metal particles gradually grow around the seed layer, and simultaneously with the growth of the metal particles, they are separated into a metal region and a binder region by a phase separation inducer. Afterwards, the metal is sintered and the binder is hardened in each different region.

[0149] Fig. 1 (b) is a conceptual diagram illustrating a connection structure according to another embodiment, which is a connection structure in which two electrodes have two opposing electrodes. The connection structure according to this embodiment includes a third electrode (120a), a fourth electrode (120b), a fifth electrode (130a), a sixth electrode (130b), and a connection material (170) electrically connecting the third electrode to the fifth electrode and the fourth electrode to the sixth electrode.

[0150] The third electrode (120a) and the fourth electrode (120b) are electrodes for electrical connection formed on the substrate, and may be, for example, a backplane substrate for attaching a micro LED, and the fifth electrode is provided at a position opposite to the third electrode, such that the electrode opposite to the third electrode is referred to as the fifth electrode, and the electrode opposite to the fourth electrode is referred to as the sixth electrode, and may be an electrode having a layered structure of molybdenum-aluminum-molybdenum.

[0151] The fifth electrode (130a) and the sixth electrode (130b) are electrodes for electrical connection formed in an element formed in an electronic component, and may be, for example, a semiconductor chip or a micro LED chip. In the case of a micro LED chip, the electrodes may be gold, and one electronic component may have two electrodes, the fifth electrode (130a) and the sixth electrode (130b), which are anode and cathode.

[0152] At this time, the gap between the third electrode and the fourth electrode (the fifth electrode and the sixth electrode) is 1 to 50 ㎛, preferably 3 to 50 ㎛, and the width of each electrode is 1 to 1000 ㎛, 3 to 80 ㎛.

[0153] Meanwhile, the spacing between the third electrode and the fifth electrode (the fourth electrode and the sixth electrode) is preferably 10 nm to 10 μm, preferably 10 nm to 1000 nm, preferably 100 nm to 450 nm, and more preferably 140 nm to 440 nm. If the spacing exceeds the above range, there is a problem of increased contact resistance.

[0154] The connecting material is a material for electrically connecting the third electrode and the fifth electrode (the fourth electrode and the sixth electrode), and is an anisotropic conductive connecting material in which electricity flows only in the connection direction of the third electrode and the fifth electrode and the fourth electrode and the sixth electrode, and electricity does not flow in a direction other than the connection direction of the third electrode and the fifth electrode (the fourth electrode and the sixth electrode).

[0155] Therefore, even if the anisotropic conductive composition is connected to the third electrode and the fourth electrode to form a film across them, electricity does not flow in the connection direction of the third electrode and the fourth electrode, so a short circuit does not occur between the third electrode and the fourth electrode.

[0156] At this time, the connecting material is positioned between the third electrode and the fifth electrode (the fourth electrode and the sixth electrode) to physically and electrically connect them, and when cured, the anisotropic conductive composition film between the third electrode and the fifth electrode is cured by laser and heat.

[0157] The anisotropic conductive film includes a metal precursor, a phase separation inducer, a curable resin, a curing agent for curing the curable resin, and a solvent for dissolving the curable resin and the curing agent.

[0158] The cured product of the anisotropic conductive film has a structure in which the sintered body formed by the reduction of metal ions derived from a metal precursor is distributed separately without belonging to the polymer region formed by the curing of the curable resin. In this case, the sintered body region and the polymer region are distributed separately from each other.

[0159] For example, if the electronic component is a micro LED, and the fifth and sixth electrodes of the micro LED are connected to the third and fourth electrodes of the substrate, respectively, the LED will light up without a short circuit.

[0160] FIG. 2 is a schematic diagram explaining a mechanism in which a region where a sintered body is located and a region where a polymer is located are hybridized with each other and have an anisotropic structure according to the reduction and sintering of metal particles and hardening of a curable resin during heat or laser curing according to the present embodiment.

[0161] Accordingly, when the anisotropic conductive film manufactured by the present embodiment is positioned between electrodes and cured, a metal sintered body initially begins to form on each surface of the LED chip electrode (120a) and the electrode (110) of the substrate. As sintering progresses, it was found that the metal sintered body grows more and more based on the metal sintered body formed on the surface, thereby connecting the LED chip electrode (120a) and the electrode (110) of the substrate to each other. That is, the metal sintered body is formed by growing the metal sintered bodies formed on each surface of the LED chip electrode (120a) and the electrode (110) of the substrate, and then bonding them to each other.

[0162] In the above description, the number of electrodes has been limited for convenience of explanation, but those skilled in the art will recognize that the same can be applied to a connection structure composed of N lower electrodes and N upper electrodes facing them.

[0163] <Example>

[0164] <Manufacturing Example 1> Manufacturing of flow control agent

[0165] 2-Ethylhexylacrylate and n-butylacrylate were purchased from Junsei Chemical Co., Ltd. Vinyl acetate (VAc) used as a co-polymer was purchased from Kanto Chemical Co., Ltd. 1-Vinyl-2-pyrrolidinone (NVP) was purchased from Aldrich Chemical Co., Ltd. Acrylic acid (AA), glycidyl methacrylate (GMA), and 2-hydroxyethyl methacrylate (MEMA), which are functional group-containing monomers, were purchased from Junsei Chemical Co., Ltd. Benzoyl peroxide (BPO) as initiator was manufactured by Youngwoo Chemical Co., Ltd., and α,α'-azobis isobutyronitrile (AIBN) was manufactured by Junsei Chemical Co., Ltd. The solvents were ethyl acetate, methanol, and toluene, all grade 1 reagents manufactured by Daewon Chemical Co., Ltd. Each monomer was charged into a 2 L four-necked flask equipped with a stirrer, thermometer, and reflux condenser according to the compositions in the table below. The entire monomer was charged, followed by the solvent. The initiator was dissolved in the solution and solvent (EAc: TOL = 7:3) and charged. Upon completion of the charge, polymerization was performed at 70°C for 8 hours with a stirring speed of 200 rpm. When the reaction was completed, the solid content was adjusted to 40% using toluene, cooled with cooling water, and Tg was measured.

[0166] The Tg of the polymer was measured using a Differential Scanning Calorimeter (DSC) Model DSC-550 from Instrument Specialists. The measurement method was as follows: first heating from room temperature to 100°C at a heating rate of 10°C / min (1 run), then cooling to -100°C using liquid nitrogen, and the Tg was investigated as the midpoint of the tangent line during the second heating (2nd run).

[0167] <Manufacturing Examples 2 to 5> Manufacturing of flow control agent

[0168] Manufacturing Examples 2 to 5 were manufactured as in Manufacturing Example 1 described above, and their compositions are summarized in Table 1.

[0169] Flow control agent Manufacturing example 1 Manufacturing example 2 Manufacturing example 3 Manufacturing example 4 Manufacturing example 5 Acrylic monomer 2-Ethylhexylacrylate 10 10 20 10 n-Buthylacrylate 55 5 Vinyl acetate 55 5 Monomer Acrylic acid (AA) 10 10 10 10 30 Glycidyl Methacrylate 55 5 5 2-Hydroxyethyl Methacrylate 55 1-Vinyl-2-Pyrrolidinone 55 15 Initiator Initiator is benzoyl peroxide; BPO)20202010α,α'-azobis isobutyronitrile (AIBN)20SolventEthyl Acetate2020202020Methanol20Toluene20202020Total100100100100100Tg(℃)18205845110

[0170] <Examples 1 to 10>: Composition for film production

[0171] ACA film composition Example-1 Example-2 Example-3 Example-4 Example-5 Example-6 Example-7 Example-8 Example-9 Example-10 Metal precursor 30 30 30 30 30 30 30 30 30 30 Flow control agent Manufacturing example 1 30 30 30 30 30 30 30 Manufacturing example 2 30 Manufacturing example 3 30 Manufacturing example 4 30 Manufacturing example 5 30 Acrylic binder (adhesion aid) Dipentaerythritol penta(meth)acrylate 10 10 10 10 10 Tetrahydrofurfuryl(meth)acrylate 10 Isodecyl(meth)acrylate, 10 Hydroxyethyl acrylate 10 2-Hydroxy ethyl metha acrylate Acrylic binder hardener Benzoyl peroxide 5 5555555 t-butyl hydroperoxide Epoxy binder (adhesion aid) YD-114E (KUKDO, Bisphenol-A type liquid epoxy resin) 10 YD-128 (KUKDO, Unmodified Bisphenol-A based Liquid Epoxy Resin) 10 YDF-170 (KUKDO, BISPHENOL-F TYPE EPOXY RESIN) Epoxy binder hardener 2-Phenyl-4-methylimidazole (aldrich) 5 2,4,6-Tris(dimethylaminomethyl)phenol (aldrich) 5 Metal particle Ag Nano particle dispersion (20nm, aldrich,730793) Cu Nano particle dispersion (WiNEL Co., Ltd., 10nm) Solvent butyl actetate15151515151515151515Toluene10101010101010101010Total (wt%) 100100100100100100100100100100,

[0172] <Examples 11 to 13, Comparative Examples 1 to 4>: Composition for film production

[0173] ACA film composition Example-11 Example-12 Example-13 Comparative Example-1 Comparative Example-2 Comparative Example-3 Comparative Example-4 Metal precursor 302020 303030 Acrylic adhesive Manufacturing example 130 30 30 3030 Manufacturing example 2 3030 Manufacturing example 3 Manufacturing example 4 Manufacturing example 5 Acrylic binder (adhesion aid) Dipentaerythritol penta(meth)acrylate 10101040 25 Tetrahydrofurfuryl(meth)acrylate Isodecyl(meth)acrylate, hydroxyethyl acrylate 2-Hydroxyethylmethacrylate Acrylic binder hardener Benzoyl peroxide 5555 15 t-butyl hydroperoxide Epoxy binder (adhesion aid) YD-114E (KUKDO, Bisphenol-A type liquid epoxy resin) YD-128 (KUKDO, Unmodified Bisphenol-A based Liquid Epoxy Resin) YDF-170 (KUKDO, BISPHENOL-F TYPE EPOXY RESIN) 10 Epoxy binder hardener 2-Phenyl-4-methylimidazole (aldrich) 2,4,6-Tris(dimethylaminomethyl)phenol (aldrich) Metal particles Ag Nano particle dispersion (20 nm, aldrich, 730793) 510 30 Cu Nano particle dispersion(WiNEL Co., Ltd.,10nm) 10 Solvent butyl actetate151515151525 Toluene101010101015 Total (wt%) 100100100100100100100,

[0174] <Experimental Example><Experimental Example 1> Physical Property Evaluation The adhesive strength and connection resistance of the film manufacturing compositions of Examples 1 to 13 and Comparative Examples 1 to 4 described above were evaluated, and the results are summarized in Tables 4 and 5.

[0175] ACA film composition Example-1 Example-2 Example-3 Example-4 Example-5 Example-6 Example-7 Example-8 Example-9 Example-10 Physical property evaluation Initial adhesion (g / cm, 90° peel strength test) 980 983 941 975 957 102 4976 1094 987 996 Adhesion after reliability evaluation (g / cm, 85° C. and RH. 85%, 1,000 hr, 90° peel strength test) 1064 1064 1019 100 1968 106 7987 1148 104 11110 Adhesion after reliability evaluation (g / cm, ?40° C. to 80° C. for 1,000 cycles, 90° peel strength test)11101121106710119941084988122110341210Initial connection resistance (Ω, 2-point probe)5.85.96.48.47.56.89.16.88.85.6Connection resistance after reliability evaluation (Ω, 85° C. and RH. 85%, 1,000 hr, 2-point probe)6.46.58.48.88.97.410.18.58.68.4Connection resistance after reliability evaluation (Ω, -40° C. to 80° C. for 1000 cycles, 2-point probe)6.76.17.47.68.86.48.47.49.19.1

[0176] ACA film composition Example-11 Example-12 Example-13 Comparative Example-1 Comparative Example-2 Comparative Example-3 Comparative Example-4 Property evaluation Initial adhesion (g / cm, 90° peel strength test) 1032987991987 Not measurable (not filmed) 518 Not measurable (not filmed) Adhesion after reliability evaluation (g / cm, 85° C. and RH. 85%, 1,000 hr, 90° peel strength test) 1031111211101061ND Adhesion after reliability evaluation (g / cm, ?40° C. to 80° C. for 1,000 cycles, 90° peel strength test) 11101211111211121ND Initial connection resistance (Ω, 2-point) probe)6.18.910.412005.4Connection resistance after reliability evaluation (Ω, 85° C. and RH. 85%, 1,000 hr, 2-point probe)6.89.811.415005.5Connection resistance after reliability evaluation (Ω, ?40° C. to 80° C. for 1,000 cycles, 2-point probe)6.99.811.515006.1

[0177] <Experimental Example 1> Measurement of Conductivity and Insulation Resistance An anisotropic conductive film manufactured with the composition of Example 1 was attached to a PI film (COF film) having copper electrodes of 8 μm in size and a spacing (space) of 13 μm between the electrodes. Next, an ITO substrate of 1.5 mm x 12 mm in size was adhered to the anisotropic conductive film, and then bonded over time using an ACF Bonder (BD-02 Tabletop Heat Bonder (Pulse heater), OHASHI ENGINEERING Co., Ltd.) under conditions of 230°C and a bonding pressure of 130 MPa. As shown in Fig. 4, an anisotropic conductive film according to the present invention was placed between the ITO substrate and the COF film, and the resistance was measured, which is summarized in Table 6 and Fig. 5. After 60 seconds, the resistance was stably measured to be 10Ω or less, confirming that the electrodes of the COF and the ITO were electrically connected.

[0178] Time (s) Measurement location 12345678301-2 Electrode 281177410151715103-4 Electrode 5534141216131719601-2 Electrode 151310776673-4 Electrode 10161076698901-2 Electrode 91510766653-4 Electrode 898655551201-2 Electrode 899666653-4 Electrode 776655551501-2 Electrode 777666663-4 Electrode 77555555

[0179] Table 7 and Fig. 6 show that the same experiment as Experimental Example 1 was performed using a non-conductive slide glass instead of an ITO substrate. As a result of measuring the electrical resistance, no resistance was measured between electrodes 1 and 2, 3 and 4. It was confirmed that there was no electrical short between electrodes 1 and 2 and 3 and 4.

[0180] Time (s) Measurement location 12345678301-2 electrode XXXXXXXX3-4 electrode XXXXXXXX601-2 electrode XXXXXXXX3-4 electrode XXXXXXXX901-2 electrode XXXXXXXX3-4 electrode XXXXXXXX1201-2 electrode XXXXXXXX3-4 electrode XXXXXXXX1501-2 electrode XXXXXXXX3-4 electrode XXXXXXXX

[0181] <Experimental Example 2> Anisotropic conductive film manufactured with the composition of Example 2 for thermal curing of anisotropic conductive film was bonded to a Ti / Al / Ti substrate measuring 1.5 mm x 12 mm, and then a PI film (COF film) having copper electrodes with an electrode size of 8 μm and a spacing (space) of 13 μm was attached on the anisotropic conductive film using an ACF Bonder (BD-02 Tabletop Heat Bonder (Pulse heater). Next, bonding was performed over time under conditions of 230°C and a bonding pressure of 130 MPa using an OHASHI ENGINEERING Co., Ltd.). The resistance measurement results of the conductive substrate sample are summarized in Table 8. According to this, it was stably measured to be less than 10Ω, and it could be confirmed that the electrodes of the COF were electrically connected to the ITO.

[0182] Line123456782-PointProbe1-2Electrode5.84.43.84.26.18.06.76.73-4Electrode6.34.63.73.33.95.75.57.2

[0183] In addition, the resistance was measured using a non-conductive slide glass instead of a Ti / Al / Ti substrate, and the results were summarized in Table 9.

[0184] Line123456782-Pointprobe1-2ElectrodeXXXXXXXX3-4ElectrodeXXXXXXXX

[0185] According to this, the electrical resistance measurement results showed that no resistance was measured between electrodes 1 and 2, 3 and 4. It was confirmed that there was no electrical short between electrodes 1 and 2 and 3 and 4. <Experimental Example 3> Laser curing of anisotropic conductive film The anisotropic conductive film (size: 1.5 mm * 12 mm) manufactured in Example 1 was attached to a Ti / Al / Ti substrate, and a PI film (COF film) formed with an electrode size of 8 μm and a gap (space) between the electrodes of 13 μm was placed on top of the anisotropic conductive film. Using Laser sintering & curing equipment (FineTek Co., Ltd.), the laser power was 300 W and applied for 10 seconds. At this time, the temperature measured by the IR camera was 250°C. The resistance was measured using the substrate manufactured in this way in the same manner as in each Example 1. The measured resistance values ​​are shown in the table. It is stably measured below 10Ω, and it can be confirmed that the electrodes of the COF and the Ti / Al / Ti substrate are electrically connected, which is summarized in Table 10.

[0186] Line123456782-Pointprobe1-2Electrode3.83.34.54.25.17.18.76.43-4Electrode5.44.14.64.35.97.77.55.9

[0187] *Also, the same experiment was performed using a non-conductive slide glass instead of a Ti / Al / Ti substrate, and the results are summarized in Table 11. According to this, the electrical resistance measurement results showed that no resistance was measured between electrodes 1 and 2, 3 and 4. It was confirmed that there was no electrical short between electrodes 1 and 2 and 3 and 4.

[0188] Line123456782-Pointprobe1-2ElectrodeXXXXXXXX3-4ElectrodeXXXXXXXX

[0189] At this time, the laser equipment used a surface laser method with a wavelength of 980 nm, as shown in Fig. 9. The laser oscillating from the laser source is uniformly output to the area to be irradiated through the optical system. When pressure is required during bonding, transparent quartz with almost no laser absorption is placed between the laser and the sample, and the laser is irradiated while applying pressure to the sample using the quartz. The laser passing through the quartz reaches the surface of the PI layer and the metal electrode layer of the COF film, and the surface temperature increases according to the laser absorption rate of the PI layer and the metal electrode layer. The heat heated by the laser for several seconds is instantaneously transferred to the anisotropic conductive film and / or the ITO or Ti / Al / Ti layer located under the metal electrode layer in a thermally conductive manner, causing sintering and curing to occur, and the bonding process is performed. At this time, the temperature of the metal electrode layer and the anisotropic conductive film was 250 ℃ in real time during the laser process through an IR camera image.

[0190] <Experimental Example 4> Electron microscope photo

[0191] In Experimental Example 3, after bonding the electrodes, the bonding material (anisotropic conductive film) area was photographed with an electron microscope and is shown in Fig. 10. According to this, it was confirmed that Ag was precipitated as a sintered body on the surface of the Cu electrode, and this was because the Ag component of the metal precursor was reduced to form a sintered body, forming a metal region as a conductive path that can electrically connect the upper and lower electrode directions. Meanwhile, the sintered body was subjected to elemental analysis using EDS and is shown in Fig. 11. As a result, it was confirmed that the main component of the sintered body was Ag.

[0192] <Experimental Example 5> Micro LED Lighting

[0193] The lighting rate of the microLED was evaluated by sintering and curing the metal precursor and polymer, respectively, using an infrared (IR) laser (1064 nm) on an anisotropic conductive film manufactured using the composition of Example 2 (Fig. 11). 100% lighting was confirmed, and cross-sectional analysis results confirmed the formation of a metal layer under the chip. Drawings and photographs related to the experiment are shown in Figs. 12 to 14.

[0194] The above description is merely illustrative of the present invention, and those skilled in the art will appreciate that various modifications may be made without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in this specification are intended to illustrate, not limit, the present invention, and the spirit and scope of the present invention are not limited by these embodiments. The scope of protection of the present invention should be interpreted by the following claims, and all techniques within a scope equivalent thereto should be interpreted as being included within the scope of the present invention.

[0195]

[0196] The present invention has high industrial applicability because, when a gap between electrodes of 30 um (or pitch) or less is required due to the integration of electronic components, a film is used to form a sintered body that is electrically conductive in only one direction, so that even when connecting an electrode and a chip of an ultra-fine pattern, no short circuit occurs.

Claims

1. A composition for manufacturing an anisotropic conductive material that electrically connects opposing first and second electrodes, A metal precursor comprising a metal ion that provides electrical conductivity to the above anisotropic conductive material; A curable resin comprising a curable polymer; A phase separation inducing agent that induces phase separation between a metal reduced from the metal ion and the curable resin; A flow control agent that shortens the curing time and controls flowability; and A composition for manufacturing an anisotropic conductive material comprising a solvent.

2. In paragraph 1, The above-mentioned phase separation inducing agent is a composition for manufacturing an anisotropic conductive material including a hydrophilic group and a lipophilic group.

3. In paragraph 2, A composition for manufacturing an anisotropic conductive material, wherein the lipophilic group has 5 to 25 carbon atoms and the hydrophilic group includes a carboxyl group (-COOH) or an amine group (- NH).

4. In paragraph 3, A composition for producing an anisotropic conductive material, wherein the compound containing the carboxyl group is at least one selected from the group consisting of caprylic acid, pelargonic acid, caproic acid, undecanic acid, lauric acid, myristic acid, behenic acid, palmitic acid, lignoceric acid, stearic acid, eicosanoic acid, and oleic acid, or a combination thereof.

5. In paragraph 3, A composition for producing an anisotropic conductive material, wherein the compound containing the above amine group is at least one selected from the group consisting of hexylamine, heptylamine, octylamine, oleylamine, decylamine, dodecylamine, 2-ethylhexylamine, and 1,3-dimethyl-n-butylamine, or a combination thereof.

6. In paragraph 1, The above composition is a composition for manufacturing an anisotropic conductive material that can be formed into a film by hardening to a certain level upon first heating at 60 to 100°C.

7. In paragraph 1, A composition for producing an anisotropic conductive material, wherein when the composition is heated and becomes a cured product between the first electrode and the second electrode, a conductive path is formed in the Z-axis direction, which is the opposite direction, and no conductive path is formed in the X-axis and Y-axis directions, which are each perpendicular to the Z-axis direction.

8. In paragraph 7, The above-mentioned cured material is a composition for manufacturing an anisotropic conductive material in which a plurality of sintered bodies formed by reduction of the above-mentioned metal ions grow in the Z-axis direction to electrically connect the first electrode and the second electrode.

9. In paragraph 8, A composition for manufacturing an anisotropic conductive material in which the plurality of sintered bodies in the above-mentioned cured product are not connected to each other in the X and Y-axis directions.

10. In paragraph 1, The above curable resin is a composition for manufacturing an anisotropic conductive material, which is a polymer resin that can be polymerized by radicals.

11. In paragraph 1, The above curable resin is a composition for manufacturing an anisotropic conductive material, wherein the curable resin is an epoxy resin or an acrylic resin.

12. In paragraph 1, A composition for producing an anisotropic conductive material, further comprising a curing agent that cures the curable resin by heat or light, wherein the curing agent comprises an amine or phosphine compound.

13. In paragraph 12, A composition for producing an anisotropic conductive material, comprising a substance selected from the group consisting of the above amine compound, 2-methyl imidazole, 2,4-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole; and tertiary amine compounds, triethylamine, benzyldimethylamine, methylbenzyldimethylamine, 2-(dimethylaminomethyl)phenol, and 2,4,6-tris(dimethylaminomethyl)phenol.

14. In paragraph 12, The above phosphine compound is, A composition for producing an anisotropic conductive material, wherein the composition comprises one selected from the group consisting of triethylphosphine, tributylphosphine, 1,8-diazabicyclo(5,4,0)undecene-7; or an organic phosphine compound, triphenylphosphine, trimethylphosphine, triethylphosphine, tributylphosphine, tri(p-methylphenyl)phosphine (Tris(4-methoxyphenyl)phosphine), and tri(nonylphenyl)phosphine.

15. In paragraph 1, The above flow control agent is a composition for manufacturing an anisotropic conductive material, which is an acrylic polymer resin having a molecular weight of 10,000 to 1,100,000.

16. In paragraph 1, The above flow control agent is a composition for manufacturing an anisotropic conductive material having a glass transition temperature (Tg) of -20 to 110°C.

17. In paragraph 1, A composition for producing an anisotropic conductive material, comprising 5 to 15 parts by weight of a phase separation inducer, 3 to 8 parts by weight of a curable resin, 3 to 8 parts by weight of a curing agent, and 15 to 25 parts by weight of a solvent, relative to 60 parts by weight of the above metal precursor.

18. In paragraph 1, The composition for producing an anisotropic conductive material further comprises nanoparticles in an amount of 5 to 15 parts by weight based on 60 parts by weight of a metal conductive precursor.

19. In paragraph 18, A composition for manufacturing an anisotropic conductive material, wherein the nanoparticle comprises one selected from the group consisting of silver (Ag), gold (Au), indium (In), copper (Cu), indium tin oxide (ITO), palladium, platinum, nickel, and iridium.

20. A metal precursor containing a metal ion that provides electrical conductivity; A curable resin comprising a curable polymer; A phase separation inducing agent that induces phase separation between the metal reduced from the metal ion and the curable resin; and An anisotropic conductive material comprising a flow control agent that shortens the curing time and controls flowability.

21. In paragraph 20, The above anisotropic conductive material is a free-standing anisotropic conductive material that is partially cured by first heating at 60 to 100°C.

22. In paragraph 21, The above anisotropic conductive material is an anisotropic conductive material in which the metal ions are reduced by second heating after the first heating by heat or light, thereby forming a sintered body that grows to form a conductive path in one direction.

23. In paragraph 20, The above conductive material is an anisotropic conductive material that is a film that electrically connects opposing first and second electrodes.

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