Low-temperature thermosetting resin composition, anisotropic conductive film, and connection structure

Abstract

The present disclosure provides a low-temperature thermosetting resin composition, an anisotropic conductive film and a connection structure. The thermosetting resin composition in the present disclosure includes the following components: (A) an alicyclic epoxy resin; (B) a crown ether compound, wherein the content of the crown ether compound accounts for 0.05% to 5.0% by weight of the low-temperature thermosetting resin composition, preferably 0.1% to 3.0% by weight; (C) a thermal cationic polymerization initiator; (D) a film-forming additive; and (E) conductive particles; wherein the low-temperature thermosetting resin composition is suitable for thermal curing to form an anisotropic conductive film.

Description

Technical Field

[0001] The present disclosure relates to the field of bonding and connecting electronic components, and in particular to a low-temperature thermosetting resin composition, an anisotropic conductive film and a connection structure. Background Art

[0002] In the fields of semiconductors and flat panel displays, anisotropic conductive films are widely used to fix electronic components or connect circuits due to their directional conductive properties, such as chip packaging (COG) that directly mounts IC chips on glass substrates and packaging of flexible circuit substrates (FOG).

[0003] As products such as semiconductors and displays become smaller and thinner, the installation site of electronic components is close to the panel display part, and the IC chip and glass substrate have also become very thin. Due to the hot pressing during connection, there will be problems such as component burning, or the circuit wiring position shift after packaging due to the relative thermal expansion difference of the circuit substrate. Especially in COG packaging, due to the curing shrinkage of the anisotropic conductive film or the thermal expansion difference between the IC chip and the glass substrate, the substrate will be warped, resulting in uneven display on the display. In addition, in terms of production costs, in order to reduce costs and improve production efficiency, it is necessary to prepare the adhesive layer material of the anisotropic conductive film to be able to complete curing at a lower temperature (for example, 140-150°C) and in a shorter time (for example, within 5 seconds).

[0004] In order to achieve the storage stability and low-temperature rapid curing of the adhesive layer material of the anisotropic conductive film, the development direction is mainly for the cationic curing system that can be cured at low temperature. Compared with the general glycidyl ether compounds, alicyclic epoxy compounds with higher cationic polymerization reactivity are used, and there is no oxygen to hinder the polymerization reaction. At the same time, when it is used in combination with a highly reactive cationic polymerization initiator, it can show a relatively low temperature curing temperature (for example, around 100°C). However, there is also a problem that polymerization will begin at a temperature of around 40 to 60°C, and the adhesive may also cure during storage, resulting in low storage stability.

[0005] In summary, there is a need to provide an adhesive material that can take into account both storage stability and low-temperature curing performance, and make the resulting anisotropic conductive film have good connection reliability. Summary of the invention

[0006] In view of this, in order to overcome any of the above-mentioned and at least one of other defects in the prior art, the present disclosure proposes a low-temperature thermosetting resin composition, which uses alicyclic epoxy resin, crown ether compound and thermal cationic polymerization initiator in the film-forming additive components, and uses the crown ether to capture the initiator cations during the storage process to inhibit the reaction. This improves the storage stability while achieving low-temperature and short-time curing, and can successfully prepare an anisotropic conductive film with good connection reliability.

[0007] In addition, the present disclosure proposes a connection structure that performs anisotropic conductive connection between a first electronic component and a second electronic component through a cured anisotropic conductive film, thereby achieving a stable connection state under low stress and reducing warping of the substrate.

[0008] In order to achieve the above object, in one aspect of the present disclosure, a low-temperature heat-curable resin composition is provided, comprising the following components:

[0009] (A) alicyclic epoxy resin;

[0010] (B) a crown ether compound, wherein the content of the crown ether compound accounts for 0.05 wt % to 5.0 wt %, preferably 0.1 wt % to 3.0 wt % of the low-temperature thermosetting resin composition;

[0011] (C) a thermal cationic polymerization initiator;

[0012] (D) film-forming additives; and

[0013] (E) conductive particles;

[0014] Among them, the low-temperature heat-curable resin composition is suitable for heat curing to prepare anisotropic conductive films.

[0015] According to an embodiment of the present disclosure, the thermal cationic polymerization initiator contains at least one of a quaternary ammonium salt composed of a quaternary ammonium cation and a borate-based anion and a sulfonium salt composed of an aromatic sulfonium cation and a borate-based anion.

[0016] According to an embodiment of the present disclosure, the quaternary ammonium salt includes dimethylphenyl (4-methoxybenzyl) ammonium tetrakis (pentafluorophenyl) borate, dimethylphenyl (4-methylbenzyl) ammonium hexafluoro tetrakis (pentafluorophenyl) borate, methylphenyl dibenzyl ammonium tetrakis (pentafluorophenyl) borate, phenyltribenzyl ammonium tetrakis (pentafluorophenyl) borate, dimethylphenyl (3,4-dimethylbenzyl) ammonium tetrakis (pentafluorophenyl) borate, N,N-diethyl-N-benzylanilinium boron tetrafluoride; the sulfonium salt includes p-hydroxyphenyl-benzyl-methylsulfonium tetrakis (pentafluorophenyl) borate, triphenylsulfonium tetrakis (pentafluorophenyl) borate, 4-hydroxyphenyl-methyl-1-naphthylmethylsulfonium tetrakis (pentafluorophenyl) borate, 4-hydroxyphenyl-methyl-1-naphthylmethylsulfonium tetrakis (pentafluorophenyl) borate, Phenyl-methyl-(2-methylbenzyl)sulfonium tetrakis(pentafluorophenyl)borate, methylphenyl[(2-thioxanthenyl)methyl]sulfonium-tetrakis(pentafluorophenyl)borate, methylphenyl[(3-thioxanthenyl)methyl]sulfonium-tetrakis(pentafluorophenyl)borate, methyl-4-hydroxyphenyl[(2-thioxanthenyl)methyl]sulfonium-tetrakis(pentafluorophenyl)borate, methyl-4-hydroxyphenyl[(3-thioxanthenyl)methyl]sulfonium-tetrakis(pentafluorophenyl)borate, 7-[di(p-tolyl)sulfonyl]-2-isopropylthioxanthenyltetrakis(pentafluorophenyl)borate, 4-(p-tert-butylphenylcarbonyl)-4'-di(p-tolyl)sulfonyl-diphenylsulfide-tetrakis(pentafluorophenyl)borate.

[0017] According to an embodiment of the present disclosure, the content of the thermal cationic polymerization initiator is 0.05 wt % to 30 wt % of the alicyclic epoxy resin, preferably 2 wt % to 15 wt %.

[0018] According to an embodiment of the present disclosure, the crown ether compound is selected from 12-crown 4-ether, 15-crown 5-ether, 18-crown 6-ether, 24-crown 8-ether, benzo-15-crown 5-ether, benzo-18-crown 6-ether, benzo-12-crown 4-ether, dibenzo-15-crown 5-ether, dibenzo-18-crown 6-ether, dibenzo-21-crown 7-ether, dibenzo-24-crown 8-ether, tribenzo-18-crown 6-ether, 4,13-diazo- 18-crown 6-ether, dicyclohexyl-18-crown 6-ether, 4'-carboxybenzo-15-crown 5-ether, 4'-carboxybenzo-18-crown 6-ether, 4'-aminobenzo-15-crown 5 ether, 4'-acetylbenzo-15-crown 5-ether, 4'-acetylbenzo-18-crown 6-ether, 4'-nitrobenzo-15-crown 5-ether, 4'-nitrobenzo-18-crown 6-ether, 4'-bromobenzo-18-crown 6 ether, 4'-bromobenzo-18-crown 6 ether Benzo-15-crown 5-ether, 1-aza-15-crown 5-ether, 1-aza-18-crown 6-ether, 1-az-12-crown 4-ether, 4,10-diaza-15-crown 5-ether, 4,10-diaza-12-crown 4-ether, N-phenylaza-15-crown 5-ether, N,N'-dibenzyl-4,13-diaza-18-crown 6-ether, 2-(hydroxymethyl)-15-crown 5-ether, 2-(hydroxymethyl)-1 2-crown 4-ether, 2-(hydroxymethyl)-18-crown 6-ether, eicosine-15-crown 5-ether, dicyclohexene-18-crown-6 ether, 4'-formylbenzo-15-crown 5-ether, 4,7,13,21,24-hexaoxa-1,10-diazabicyclo[8.8]hexadecane, bis(1,4-phenylene)-34-crown 10-ether, 18-crown-5[4-(2,4-dinitrophenylazo)phenol].

[0019] According to an embodiment of the present disclosure, the alicyclic epoxy resin is selected from 2-(3,4-epoxycyclohexyl-5,5-spiro-3,4-epoxy)cyclohexane-dioxane, 3,4-epoxy-1-methylcyclohexyl-3,4-epoxy-1-methylhexanecarboxylate, 3,4-epoxy-3-methylcyclohexylmethyl-3,4-epoxy-3-methylcyclohexanecarboxylate, 3,4-epoxy-5-methylcyclohexylmethyl-3,4-epoxy-5-methyl At least one of 3,4-epoxycyclohexanecarboxylate, 3,4-epoxy-6-methylcyclohexylcarboxylate, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, 6-methyl-3,4-epoxycyclohexylmethyl-6-methyl-3,4-epoxycyclohexanecarboxylate, ethylene bis(3,4-epoxycyclohexanecarboxylate), dicyclopentadiepoxide, bis(3,4-epoxycyclohexylmethyl)adipate, and methylene bis(3,4-epoxycyclohexane).

[0020] According to an embodiment of the present disclosure, the content of the alicyclic epoxy resin accounts for 10 wt % to 60 wt %, preferably 20 wt % to 50 wt % of the low-temperature thermosetting resin composition.

[0021] According to an embodiment of the present disclosure, the film-forming additive includes an epoxy resin or a phenoxy resin that is solid at room temperature; the epoxy resin is preferably selected from at least one of bisphenol-type epoxy resin, novolac-type epoxy resin, naphthalene-type epoxy resin, and biphenyl-type epoxy resin; the phenoxy resin is preferably selected from at least one of fluorene-type phenoxy resin, bisphenol-type phenoxy resin, novolac-type phenoxy resin, naphthalene-type phenoxy resin, and biphenyl-type phenoxy resin.

[0022] According to an embodiment of the present disclosure, the content of the film-forming additive component accounts for 10 wt % to 70 wt %, preferably 20 wt % to 50 wt % of the low-temperature thermosetting resin composition.

[0023] According to an embodiment of the present disclosure, the conductive particles are selected from at least one of nickel, cobalt, silver, copper, gold, palladium, solder, and metal-plated resin particles;

[0024] According to the embodiment of the present disclosure, the content of the conductive particles is 50 to 100,000 or less per mm 2 Conductive film, 200~70000 pieces / mm 2 Conductive film.

[0025] In another aspect of the present disclosure, there is provided an anisotropic conductive film, which is made by thermally curing the above-mentioned low-temperature thermal curing resin composition;

[0026] According to an embodiment of the present disclosure, the temperature of thermal curing is 140-150° C., and the curing time is within 5 seconds.

[0027] In another aspect of the present disclosure, a connection structure is provided, which is formed by anisotropically conductively connecting a first electronic component and a second electronic component using the anisotropic conductive film.

[0028] The low-temperature heat-curable resin composition provided by the present disclosure adds alicyclic epoxy resin, crown ether compound and thermal cationic polymerization initiator to the film-forming additive component, and uses the crown ether to capture the initiator cation during storage to inhibit the reaction, thereby achieving low-temperature and short-time curing while improving storage stability. The problem of low storage stability caused by polymerization at 40-60°C when using alicyclic epoxy resin in the related art is solved.

[0029] The connection state of the connection structure provided by the present disclosure after curing is stable under low stress, which can reduce the warping of the substrate and greatly increase the connection reliability. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solution and advantages of the present disclosure more clear, the present disclosure is further described in detail below in conjunction with specific embodiments. However, the present disclosure is not limited to the following embodiments.

[0031] The terms used herein are only for describing specific embodiments and are not intended to limit the present disclosure. The terms "including", "comprising", etc. used herein indicate the presence of features, steps, operations and / or components, but do not exclude the presence or addition of one or more other features, steps, operations or components. All terms (including technical and scientific terms) used herein have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein should be interpreted as having meanings consistent with the context of this specification and should not be interpreted in an idealized or overly rigid manner.

[0032] In the process of realizing the present disclosure, it was found that a cation-curing composition of an alicyclic epoxy resin, a crown ether compound and a thermal cationic polymerization initiator was used as a film-forming additive in a low-temperature heat-curing resin composition, wherein the crown ether captures the initiator cation and inhibits the reaction, thereby achieving low-temperature and short-time curing while improving storage stability. Based on the above anisotropic conductive film, a connection structure with high connection reliability that minimizes substrate warping under relatively low stress can be obtained.

[0033] In one aspect of the present disclosure, the low-temperature heat-curable resin composition of the present disclosure is mainly composed of alicyclic epoxy resin, crown ether compound, thermal cationic polymerization initiator, film-forming additive and conductive particles as essential components. More specifically, a heat-curable resin composition is provided, comprising the following components:

[0034] (A) alicyclic epoxy resin;

[0035] (B) a crown ether compound, wherein the content of the crown ether compound is 0.05% to 5.0% by weight, preferably 0.1% to 3.0% by weight of the low-temperature thermosetting resin composition, for example, 0.05%, 0.1%, 0.2%, 0.3%, 1.0%, 2.0%, 3.0%, 4.0%, 5.0% by weight, etc.;

[0036] (C) a thermal cationic polymerization initiator;

[0037] (D) film-forming additives;

[0038] (E) conductive particles;

[0039] Among them, the low-temperature heat-curable resin composition is suitable for heat curing to prepare anisotropic conductive films.

[0040] According to the embodiments of the present disclosure, the low-temperature heat-curable resin composition provided by the present disclosure adds alicyclic epoxy resin, crown ether compound and thermal cationic polymerization initiator to the film-forming additive components, and uses the crown ether to capture the initiator cations during the storage process to inhibit the reaction, thereby achieving low-temperature and short-time curing while improving the storage stability. The problem of low storage stability caused by polymerization at 40 to 60°C when using alicyclic epoxy resin in the related art is solved. The connection state of the connection structure provided by the present disclosure after curing is stable under low stress, which can reduce warping of the substrate and greatly increase the connection reliability.

[0041] According to the embodiments of the present disclosure, the alicyclic epoxy resin used in the present disclosure is a structure in which an epoxy group is directly arranged on the alicyclic skeleton. The alicyclic epoxy resin is liquid at room temperature. From the viewpoint of reactivity, the epoxy group is preferably difunctional or more. For example, it can be 2-(3,4-epoxycyclohexyl-5,5-spiro-3,4-epoxy)cyclohexane-dioxane, 3,4-epoxy-1-methylcyclohexyl-3,4-epoxy-1-methylhexanecarboxylate, 3,4-epoxy-3-methylcyclohexylmethyl-3,4-epoxy-3-methylcyclohexanecarboxylate, 3,4-epoxy-5-methylcyclohexylmethyl-3,4-epoxy-5-methylcyclohexanecarboxylate , 3,4-epoxy-6-methylcyclohexylcarboxylate, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, 6-methyl-3,4-epoxycyclohexylmethyl-6-methyl-3,4-epoxycyclohexanecarboxylate, ethylene bis(3,4-epoxycyclohexanecarboxylate), dicyclopentadiepoxide, bis(3,4-epoxycyclohexylmethyl)adipate, methylene bis(3,4-epoxycyclohexane), etc.

[0042] According to the embodiments of the present disclosure, the content of the alicyclic epoxy resin accounts for 10% to 60% by weight of the low-temperature thermosetting resin composition, preferably 20% to 50% by weight. Among them, the ratio of the content of the alicyclic epoxy resin to the low-temperature thermosetting resin composition can be 10% by weight, 20% by weight, 30% by weight, 40% by weight, 50% by weight, 60% by weight, etc. If the content of the alicyclic epoxy resin accounts for less than 10% by weight of the low-temperature thermosetting resin composition, a sufficient cured product cannot be obtained, resulting in unstable connection characteristics; if it exceeds 60% by weight, the film-forming additive is insufficient, which will lead to insufficient film-forming properties or insufficient amount of conductive particles, resulting in poor connection and the like.

[0043] According to an embodiment of the present disclosure, the thermal cationic polymerization initiator contains at least one of a quaternary ammonium salt composed of a quaternary ammonium cation and a borate-based anion and a sulfonium salt composed of an aromatic sulfonium cation and a borate-based anion.

[0044] According to an embodiment of the present disclosure, the borate anion is preferably BF4- or (BX4), wherein X represents a phenyl group substituted with at least two or more fluorine or trifluoromethyl groups.

[0045] According to an embodiment of the present disclosure, quaternary ammonium salts include dimethylphenyl (4-methoxybenzyl) ammonium tetrakis (pentafluorophenyl) borate, dimethylphenyl (4-methylbenzyl) ammonium hexafluorotetrakis (pentafluorophenyl) borate, methylphenyl dibenzyl ammonium tetrakis (pentafluorophenyl) borate, phenyl tribenzyl ammonium tetrakis (pentafluorophenyl) borate, dimethylphenyl (3,4-dimethylbenzyl) ammonium tetrakis (pentafluorophenyl) borate, N, N-diethyl-N-benzylanilinium boron tetrafluoride; wherein the quaternary ammonium salt compound can be a product manufactured by King Industries with the trade name "CXC-1821", etc.

[0046] According to an embodiment of the present disclosure, the sulfonium salt includes p-hydroxyphenyl-benzyl-methylsulfonium tetrakis(pentafluorophenyl)borate, triphenylsulfonium tetrakis(pentafluorophenyl)borate, 4-hydroxyphenyl-methyl-1-naphthylmethylsulfonium tetrakis(pentafluorophenyl)borate, 4-hydroxyphenyl-methyl-(2-methylbenzyl)sulfonium tetrakis(pentafluorophenyl)borate, methylphenyl[(2-thioxanthenyl)methyl]sulfonium-tetrakis(pentafluorophenyl)borate, methylphenyl[(3-thioxanthenyl)methyl]sulfonium -tetrakis(pentafluorophenyl)borate, methyl-4-hydroxyphenyl[(2-thioxanthenyl)methyl]sulfonium-tetrakis(pentafluorophenyl)borate, methyl-4-hydroxyphenyl[(3-thioxanthenyl)methyl]sulfonium-tetrakis(pentafluorophenyl)borate, 7-[di(p-tolyl)sulfonyl]-2-isopropylthioxanthenyltetrakis(pentafluorophenyl)borate, 4-(p-tert-butylphenylcarbonyl)-4'-di(p-tolyl)sulfonyl-diphenylsulfide-tetrakis(pentafluorophenyl)borate.

[0047] According to an embodiment of the present disclosure, the content of the thermal cationic polymerization initiator accounts for 0.05% to 30% by weight of the alicyclic epoxy resin, preferably 2% to 15% by weight. The content of the thermal cationic polymerization initiator to the alicyclic epoxy resin can be 0.05%, 0.1%, 0.2%, 0.5%, 1%, 2%, 5%, 10%, 15%, 20%, 30%, etc. When the content of the thermal cationic polymerization initiator is within this range, the anisotropic conductive film obtained thereby has excellent low-temperature and short-time curing properties and storage stability.

[0048] According to the embodiments of the present disclosure, the alicyclic epoxy resin has good reactivity with the thermal cationic polymerization initiator, and thus has excellent low-temperature curing properties, is a resin with high heat resistance and good adhesion to the substrate. Its excellent reactivity can reduce the amount of uncured material remaining in the cured product, and can suppress the increase of shrinkage stress even in a high temperature and high humidity environment, thereby improving high temperature and high humidity resistance.

[0049] According to an embodiment of the present disclosure, the crown ether compound is selected from 12-crown 4-ether, 15-crown 5-ether, 18-crown 6-ether, 24-crown 8-ether, benzo-15-crown 5-ether, benzo-18-crown 6-ether, benzo-12-crown 4-ether, dibenzo-15-crown 5-ether, dibenzo-18-crown 6-ether, dibenzo-21-crown 7-ether, dibenzo-24-crown 8-ether, tribenzo-18-crown 6-ether, 4,13-diazo- 18-crown 6-ether, dicyclohexyl-18-crown 6-ether, 4'-carboxybenzo-15-crown 5-ether, 4'-carboxybenzo-18-crown 6-ether, 4'-aminobenzo-15-crown 5 ether, 4'-acetylbenzo-15-crown 5-ether, 4'-acetylbenzo-18-crown 6-ether, 4'-nitrobenzo-15-crown 5-ether, 4'-nitrobenzo-18-crown 6-ether, 4'-bromobenzo-18-crown 6 ether, 4'-bromobenzo-18-crown 6 ether Benzo-15-crown 5-ether, 1-aza-15-crown 5-ether, 1-aza-18-crown 6-ether, 1-az-12-crown 4-ether, 4,10-diaza-15-crown 5-ether, 4,10-diaza-12-crown 4-ether, N-phenylaza-15-crown 5-ether, N,N'-dibenzyl-4,13-diaza-18-crown 6-ether, 2-(hydroxymethyl)-15-crown 5-ether, 2-(hydroxymethyl)-1 Any one of 2-crown 4-ether, 2-(hydroxymethyl)-18-crown 6-ether, eicosine-15-crown 5-ether, dicyclohexene-18-crown-6 ether, 4'-formylbenzo-15-crown 5-ether, 4,7,13,21,24-hexaoxa-1,10-diazabicyclo[8.8]hexadecane, bis(1,4-phenylene)-34-crown 10-ether, and 18-crown-5[4-(2,4-dinitrophenylazo)phenol]. Among them, any one of 18-crown 6-ether, benzo-18-crown 6-ether, D-dibenzo-18-crown 6-ether, tribenzo-18-crown 6-ether, and dicyclohexyl-18-crown 6-ether is preferred. From the viewpoint of easy availability of cationic ions and easy availability of industrial products, any of 18-crown 6-ether, benzo-18-crown 6-ether, D-dibenzo-18-crown 6-ether, tribenzo-18-crown 6-ether and dicyclohexyl-18-crown 6-ether is preferred.

[0050] According to the embodiments of the present disclosure, the present disclosure uses the molecular holes of the crown ether to capture free ammonium cations and sulfonium cations to inhibit the reaction, thereby improving the storage stability. Since the alicyclic epoxy resin has good reactivity with the thermal cationic polymerization initiator, it has excellent low-temperature curing properties. By adding the crown ether under this condition, the reaction activity is inhibited, so that the stability of the low-temperature heat-curing resin composition is improved while the low-temperature heat-curing effect is good, and the possibility of easy curing during storage is reduced.

[0051] According to the embodiments of the present disclosure, crown ethers can improve storage stability with a small addition amount without affecting the existing curing characteristics. The content of the crown ether compound accounts for 0.05% to 5.0% by weight of the low-temperature thermosetting resin composition, preferably 0.1% to 3.0% by weight. If the ratio of the content of the crown ether compound to the low-temperature thermosetting resin composition is less than 0.05% by weight, the effect of improving storage stability cannot be achieved; if it exceeds 3.0% by weight, the water absorption rate increases, or the connection reliability of the low-temperature thermosetting resin composition is deteriorated.

[0052] According to an embodiment of the present disclosure, the film-forming additive component is a component for forming a low-temperature thermosetting resin composition into a film, and an epoxy resin or a phenoxy resin that is solid at room temperature is used as an essential component.

[0053] According to an embodiment of the present disclosure, the film-forming additive includes an epoxy resin or a phenoxy resin that is solid at room temperature; the epoxy resin is preferably selected from at least one of bisphenol-type epoxy resin, novolac-type epoxy resin, naphthalene-type epoxy resin, and biphenyl-type epoxy resin; the phenoxy resin is preferably selected from at least one of fluorene-type phenoxy resin, bisphenol-type phenoxy resin, novolac-type phenoxy resin, naphthalene-type phenoxy resin, and biphenyl-type phenoxy resin.

[0054] According to the embodiments of the present disclosure, considering the film-forming property and processing property, the epoxy resin is preferably a bisphenol epoxy resin. The epoxy resin may be a product of KUKDO CEMICAL (Kukdo Chemical Co., Ltd.) with the trade name "YD-020" or the like; the phenoxy resin may be a product of Nippon Steel Chemical Materials Co., Ltd. with the trade name "YP-50" or the like.

[0055] According to the embodiments of the present disclosure, further, the following film-forming auxiliary components may also be used: unsaturated polyester resin, saturated polyester resin, butadiene resin, polyolefin resin, etc.

[0056] According to the embodiments of the present disclosure, the epoxy resin and phenoxy resin, which are solid at room temperature, have excellent film-forming properties, processability, and connection reliability, and will not hinder the cationic polymerization reaction, so the curing reaction can be completed together under the low temperature and short time conditions of the alicyclic epoxy resin, the thermal cationic polymerization initiator, and the crown ether compound. In addition, even after the reliability test under the high temperature and high humidity environment, the peeling of the connection part of the connection structure can be significantly suppressed.

[0057] According to the embodiments of the present disclosure, the content of the film-forming additive is 10% to 70% by weight of the low-temperature thermosetting resin composition, preferably 20% to 50% by weight. For example, it can be 10%, 20%, 30%, 40%, 50%, 60%, 70%, etc. The film-forming additive within this range can exert sufficient film-forming ability.

[0058] According to an embodiment of the present disclosure, the conductive particles are selected from at least one of nickel, cobalt, silver, copper, gold, palladium, solder, and metal-plated resin particles.

[0059] According to the embodiment of the present disclosure, the content of the conductive particles is 50 to 100,000 or less per mm 2 Conductive film, 200~70000 pieces / mm 2 Conductive film. For example, 50 pieces / mm 2 , 80 pieces / mm 2 , 100 pieces / mm 2 , 1000 pieces / mm 2 , 10000pcs / mm 2 , 100000 pieces / mm 2 The amount of the ions present can be measured by counting them using an optical microscope.

[0060] According to an embodiment of the present disclosure, the average particle size of the conductive particles can cope with the deviation of the wiring height, and can suppress the increase of the on-resistance and the occurrence of short circuits. The particle size of the conductive particles can be measured by a general particle size distribution measuring device, and the average particle size can also be measured using a particle size distribution measuring device. The average particle size is preferably 2.5 μm to 30 μm, more preferably 3 μm to 20 μm. For example, it can be 2.5 μm, 3 μm, 4 μm, 8 μm, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, etc.

[0061] According to the embodiments of the present disclosure, the amount of conductive particles present in the low-temperature thermosetting resin composition can suppress the reduction in the conductive particle capture efficiency and suppress the occurrence of short circuits. The conductive particles can be a product named "Mircopearl" by Sekisui Chemical Co., Ltd. and a product named "BRIGHT" by Nippon Chemical Co., Ltd., etc.

[0062] According to the embodiments of the present disclosure, the low-temperature thermosetting resin composition may contain inorganic fillers, organic fillers, silane coupling agents, colorants, etc. as appropriate in its components, depending on the type of circuit board to be connected, and may be used according to appropriate purposes.

[0063] According to the embodiments of the present disclosure, the inorganic filler may be silicon dioxide, titanium oxide, aluminum hydroxide, etc. Silicon dioxide can reduce the moisture absorption rate and linear expansion coefficient of the cured product and increase the elastic modulus, thereby improving the connection reliability. Titanium oxide can color the circuit connection material black or white, etc., and it is easy to confirm whether the circuit connection material is pasted in the appropriate position on the circuit substrate. Aluminum hydroxide plays a role in neutralizing the acid remaining in the resin after curing, and has an effect on the corrosion of the circuit electrode.

[0064] According to the embodiments of the present disclosure, the organic filler can be particles composed of copolymers containing acrylic resin, silicone resin, butadiene rubber, polyester, polyurethane, polyvinyl butyral, polyarylate, polymethyl methacrylate, polystyrene, NBR, SBR, etc. as components, or particles of core-shell structure. It can be used alone or in combination. This circuit connection material containing organic fillers plays an effect in improving adhesion and stress relaxation and impact resistance after curing.

[0065] According to the embodiments of the present disclosure, in order to improve the adhesion to the glass substrate, a silane coupling agent may also be used. There is no particular limitation on the silane coupling agent, and it can be appropriately selected according to the purpose, for example, it can be an epoxy silane coupling agent, an acrylic silane coupling agent, a thiol silane coupling agent, an amine silane coupling agent, etc.

[0066] In another aspect of the present disclosure, an anisotropic conductive film is provided, which is prepared by thermally curing the above-mentioned low-temperature thermal curing resin composition.

[0067] According to the embodiments of the present disclosure, when the anisotropic conductive film is used for conductive connection of electronic components, the anisotropic conductive film can be rapidly solidified at low temperature and has good stability during storage, thereby avoiding solidification when stored at 40-60°C.

[0068] According to an embodiment of the present disclosure, preferably, the temperature of thermal curing is 140-150°C, for example, it can be 140°C, 142°C, 145°C, 148°C, 150°C, etc., and the curing time is within 5 seconds, for example, it can be 1 second, 2 seconds, 3 seconds, 4 seconds, 5 seconds, etc.

[0069] According to an embodiment of the present disclosure, the method for manufacturing an anisotropic conductive film provided by the present disclosure is to first evenly disperse an inorganic filler in an organic solvent such as toluene, then dissolve a film-forming additive in the dispersed solution, and mix an alicyclic epoxy resin, a crown ether compound, a thermal cationic polymerization initiator and conductive particles therein to form a coating, form the coating into a film by a known film-forming method, and then thermally cure at low temperature to manufacture the anisotropic conductive film.

[0070] According to the embodiments of the present disclosure, the anisotropic conductive film of the present disclosure can be a single layer or a double layer structure of a layer containing conductive particles and a layer not containing conductive particles. By forming a double layer structure, the particle capture efficiency during connection can be improved, thereby reducing the use of high-priced conductive particles and reducing manufacturing costs.

[0071] According to the disclosed embodiment, the thickness of the anisotropic conductive film can be coated to a thickness that can fully fill the electrode portion of the circuit substrate, and also depends on the size and number of the electrodes. Generally, it can be 3 to 10 μmm thicker than the height of the electrode.

[0072] In another aspect of the present disclosure, a connection structure is provided, which is formed by anisotropically conductively connecting a first electronic component and a second electronic component using the anisotropic conductive film.

[0073] According to the embodiment of the present disclosure, the first electronic component may be, for example, an electrode portion of a first circuit board, and the second electronic component may be, for example, a connection portion of a second printed circuit board.

[0074] According to the embodiments of the present disclosure, the anisotropic conductive film can be preferably used when an anisotropic conductive connection is performed between a first circuit substrate such as an IC chip, COF, or FPC and a second wiring circuit substrate such as a glass circuit substrate, a plastic circuit substrate, a rigid circuit substrate, a ceramic circuit substrate, or a polyimide circuit substrate. In addition, a known method can be used as a method for connecting electronic components of anisotropic conductive film.

[0075] The low-temperature thermosetting resin composition, anisotropic conductive film and connection structure disclosed in the present invention provide a method with excellent storage stability and cost-effectiveness for the research of anisotropic conductive film, which has far-reaching significance for the development of adhesive materials in electronic products.

[0076] In order to make the purpose, technical scheme and advantages of the present disclosure more clear, the present disclosure is further described in detail below in conjunction with specific examples. The test materials and reagents used in the following examples, unless otherwise specified, can be obtained from commercial sources. If no specific techniques or conditions are specified in the examples, they are all conventional methods and can be carried out according to the techniques or conditions described in the literature in the field or according to the product instructions.

[0077] Comparative Example 1: Low-temperature thermosetting resin composition

[0078] (3,4,3',4'-diepoxy)bicyclohexane (trade name TTA-800, manufactured by TETRA) is used as component (A); quaternary ammonium salt compound (trade name CXC-1821, manufactured by King Industries) is used as component (C); phenoxy resin (product name YP-50, manufactured by Nippon Steel Chemical & Materials Co., Ltd.) is used as component (D); the mixing ratio of each component is shown in Table 1. In addition, conductive particles (E) with an average particle size of 3μm (trade name: Mircopearl, manufactured by Sekisui Chemical Co., Ltd., Ni-plated resin particles) are used to uniformly disperse to obtain a low-temperature thermosetting resin composition, that is, an adhesive composition. Furthermore, using a coating device, the adhesive composition is applied on a 50μm thick peeling PET film, and a hot air drying at 50°C for 5 minutes is obtained to obtain an adhesive layer with a thickness of 18μm. The mixing ratio of each component is shown in Table 1.

[0079] Comparative Example 2: Low-temperature thermosetting resin composition

[0080] Compared with Comparative Example 1, the component (C) was changed to an aromatic sulfonium salt (trade name TR-TAG-50108, manufactured by TRONLY Corporation), and an adhesive layer was obtained by the same method as in Comparative Example 1. The mixing ratio of each component is shown in Table 1.

[0081] Example 1: Low temperature heat curing resin composition

[0082] Compared with Comparative Example 1, component (B) 18 crown 6-ether (trade name 18 Crown-6, manufactured by ANEJI Co., Ltd.) was added, and an adhesive layer was obtained in the same manner as in Comparative Example 1. The mixing ratio of each component is shown in Table 1.

[0083] Example 2: Low temperature heat curing resin composition

[0084] Compared with Comparative Example 2, component (B) 18 crown 6-ether (trade name 18 Crown-6, manufactured by ANEJI Co., Ltd.) was added, and an adhesive layer was obtained in the same manner as in Comparative Example 1. The mixing ratio of each component is shown in Table 1.

[0085] Example 3: Low temperature heat curing resin composition

[0086] Compared with Example 1, the component (D) was changed to a solid epoxy resin (product name YD-020, manufactured by KUKDO CHEMICAL Co., Ltd.) and mixed. The mixing ratio of each component is shown in Table 1.

[0087] Example 4: Low temperature heat curing resin composition

[0088] Compared with Example 1, component (B) was changed to benzo-15 crown-5 ether (trade name: Benzo-15 Crown-5, manufactured by ANEG Corporation), and an anisotropic conductive film was obtained in the same manner as in Example 1. The mixing ratio of each component is shown in Table 1.

[0089] The performance test of the low-temperature heat-curable resin composition of each of the above-mentioned Examples 1 to 4 and Comparative Examples 1 to 2 was carried out, and the specific test method is as follows:

[0090] 1. Differential Scanning Calorimeter (DSC) Measurement

[0091] The adhesive layer obtained in each embodiment and comparative example was measured using differential scanning calorimetry (DSC250, manufactured by TA Corporation). The sample amount was 5 mg, the measurement temperature range was 50-250°C, and the heating rate was 10°C / min. The heat start temperature, heat end temperature, and heat value were measured. The results are shown in Table 1.

[0092] 2. Storage stability evaluation

[0093] The adhesive layer obtained in each example and comparative example was placed in a constant temperature device at 40°C for 48 hours. The adhesive layer after being placed at 40°C was subjected to DSC measurement, and the storage stability was determined based on the calorific value reduction rate. A reduction rate of less than 10% was ○, and a reduction rate of more than 10% was ×. The results are shown in Table 1.

[0094] Heat value reduction rate (%) = [(heat value before 40°C storage - heat value after 40°C storage) / heat value before 40°C storage]

[0095] Example 5: Connection structure fabrication

[0096] An IC chip (shape: 1.6mm×15.1mm, bump height: 12μm), a glass substrate (OA-10G manufactured by Nippon Electric Glass Co., Ltd., shape 40mm×20mm, thickness 0.5mm, surface ITO (indium tin oxide) wiring spacing (wiring width 22μm, line spacing width 8μm)), the adhesive layer obtained in each embodiment and comparative example is cut into a size of 2×20mm, and attached to the glass substrate, and heated and pressed under the connection conditions of temperature 140°C and 160°C, pressure and time 60MPa for 5 seconds, and the cured anisotropic conductive film connects the IC chip and the glass substrate to obtain a connected structure.

[0097] The performance test of the connection structure of the above embodiment 5 is carried out, and the specific test method is as follows:

[0098] 1. Determination of connection resistance

[0099] The connection resistance after the connection structure is connected is measured, and the connection resistance after exposure to high temperature and high humidity environment (85°C / 85%RH / 500 hours) is measured. The function tester (model: RM3545, manufactured by HIOKI) is used for measurement, and the resistance value when 1mA current flows is measured by the 4-terminal method. After exposure to high temperature and high humidity, the connection resistance value is judged as ○ if it is less than 10Ω, and × if it is greater than 10Ω. The results are shown in Table 1.

[0100] Table 1

[0101]

[0102] ※TTA-800: alicyclic epoxy resin (structure name: (3,4,3',4'-dicycloxyl)bicyclohexane, manufactured by TETRA Corporation)

[0103] ※18Crown-6: Crown ether compound (structure name 18Crown-6-Ether, manufactured by Anergy Co., Ltd.)

[0104] ※Benzo-15Crown-5: Crown ether compound (Structural name: Benzo-15Crown-5-Ether, manufactured by Anergy Co., Ltd.)

[0105] ※CXC-1821: Quaternary ammonium salt (structure name: dimethylphenyl (4-methoxybenzyl) ammonium tetrakis (pentafluorophenyl) borate)

[0106] ※TR-TAG-50108: Aromatic sulfonium salt (structure name: p-hydroxyphenyl-benzyl-methylsulfonium tetrakis(pentafluorophenyl)borate, manufactured by TRONLY)

[0107] ※YP-50: Phenoxy resin (Structural name: bisphenol A type phenoxy resin, manufactured by Nippon Steel Chemical & Materials Co., Ltd.)

[0108] ※YD-020: Epoxy resin (Structural name: bisphenol A type epoxy resin, manufactured by KOKUDO Co., Ltd.)

[0109] As can be seen from Table 1 above, the low-temperature thermosetting resin compositions of Examples 1 to 4 contain crown ethers, and after being placed at 40°C for 48 hours, the reduction rate of heat generation is less than 10%, indicating good storage stability. However, the compositions of Comparative Examples 1 and 2 do not use crown ethers, and the heat generation is greatly reduced after being placed at 40°C for 48 hours, and the storage stability is deteriorated.

[0110] In Example 5, the connection structure obtained by using the low-temperature thermosetting resin composition of Examples 1 to 4 has a connection resistance value of less than 10Ω after exposure to high temperature and high humidity, even at a low temperature connection temperature of 140°C, indicating that the connection state is stable under low stress. The connection structure was made at a connection temperature of 140°C using the low-temperature thermosetting resin composition of Comparative Examples 1 and 2. Since no crown ether compound was used, the resistance value was more than 10Ω after 85°C / 85%RH / 500 hours, and the connection state became unstable.

[0111] In summary, the low-temperature thermosetting resin composition of the present disclosure has excellent storage stability and can be cured at a relatively low temperature (eg, 140-150° C.) and in a short time (eg, within 5 seconds). Therefore, the connection state of the anisotropic conductive film after curing is stable under low stress.

[0112] The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the present disclosure. It should be understood that the above description is only a specific embodiment of the present disclosure and is not intended to limit the present disclosure. Any modifications, equivalent substitutions, etc. made within the spirit and principles of the present disclosure should be included in the protection scope of the present disclosure.

Claims

1. A low temperature heat curing resin composition comprising the following components: (A) Cycloaliphatic epoxy resin; (B) a crown ether compound, wherein the content of the crown ether compound accounts for 0.1 wt % to 3.0 wt % of the low-temperature thermosetting resin composition; (C) a thermal cationic polymerization initiator containing at least one of a quaternary ammonium salt composed of a quaternary ammonium cation and a borate anion and a sulfonium salt composed of an aromatic sulfonium cation and a borate anion; (D) film-forming additives; and (E) conductive particles; in, The low-temperature heat-curable resin composition is suitable for heat curing to form an anisotropic conductive film; The crown ether compound is selected from 12-crown 4-ether, 15-crown 5-ether, 18-crown 6-ether, 24-crown 8-ether, benzo-15-crown 5-ether, benzo-18-crown 6-ether, benzo-12-crown 4-ether, dibenzo-15-crown 5-ether, dibenzo-18-crown 6-ether, dibenzo-21-crown 7-ether, dibenzo-24-crown 8-ether, tribenzo-18-crown 6-ether, 4,13- Diazo-18-crown-6-ether, dicyclohexyl-18-crown-6-ether, 4'-carboxybenzo-15-crown-5-ether, 4'-carboxybenzo-18-crown-6-ether, 4'-aminobenzo-15-crown-5-ether, 4'-acetylbenzo-15-crown-5-ether, 4'-acetylbenzo-18-crown-6-ether, 4'-nitrobenzo-15-crown-5-ether, 4'-nitrobenzo-18-crown-6-ether, 4'-bromobenzo 1-aza-15-crown-5-ether, 1-aza-18-crown-6-ether, 1-aza-12-crown-4-ether, 4,10-diaza-15-crown-5-ether, 4,10-diaza-12-crown-4-ether, N-phenylaza-15-crown-5-ether, N,N'-dibenzyl-4,13-diaza-18-crown-6-ether, 2 Any one of -(hydroxymethyl)-15-crown 5-ether, 2-(hydroxymethyl)-12-crown 4-ether, 2-(hydroxymethyl)-18-crown 6-ether, eicosyl-15-crown 5-ether, dicyclohexene-18-crown 6-ether, 4'-formylbenzo-15-crown 5-ether, bis(1,4-phenylene)-34-crown 10-ether, and 18-crown-5[4-(2,4-dinitrophenylazo)phenol].

2. The low-temperature thermosetting resin composition according to claim 1, wherein The quaternary ammonium salts include dimethylphenyl (4-methoxybenzyl) ammonium tetrakis (pentafluorophenyl) borate, dimethylphenyl (4-methylbenzyl) ammonium hexafluoro tetrakis (pentafluorophenyl) borate, methylphenyl dibenzylammonium tetrakis (pentafluorophenyl) borate, phenyltribenzylammonium tetrakis (pentafluorophenyl) borate, dimethylphenyl (3, 4-dimethylbenzyl) ammonium tetrakis (pentafluorophenyl) borate, N, N-diethyl-N-benzylaniline boron tetrafluoride; The sulfonium salts include p-hydroxyphenyl-benzyl-methylsulfonium tetrakis(pentafluorophenyl)borate, triphenylsulfonium tetrakis(pentafluorophenyl)borate, 4-hydroxyphenyl-methyl-1-naphthylmethylsulfonium tetrakis(pentafluorophenyl)borate, 4-hydroxyphenyl-methyl-(2-methylbenzyl)sulfonium tetrakis(pentafluorophenyl)borate, methylphenyl[(2-thioxanthenyl)methyl]sulfonium-tetrakis(pentafluorophenyl)borate, methylphenyl[(3-thioxanthenyl)methyl]sulfonium-tetrakis(pentafluorophenyl)borate borate, methyl-4-hydroxyphenyl[(2-thioxanthenyl)methyl]sulfonium-tetrakis(pentafluorophenyl)borate, methyl-4-hydroxyphenyl[(3-thioxanthenyl)methyl]sulfonium-tetrakis(pentafluorophenyl)borate, 7-[di(p-tolyl)sulfonyl]-2-isopropylthioxanthenyltetrakis(pentafluorophenyl)borate, 4-(p-tert-butylphenylcarbonyl)-4'-di(p-tolyl)sulfonyl-diphenylsulfide-tetrakis(pentafluorophenyl)borate.

3. The low-temperature thermosetting resin composition according to claim 1 or 2, wherein The content of the thermal cationic polymerization initiator accounts for 0.05 wt % to 30 wt % of the alicyclic epoxy resin.

4. The low-temperature thermosetting resin composition according to claim 3, wherein The content of the thermal cationic polymerization initiator accounts for 2 wt % to 15 wt % of the alicyclic epoxy resin.

5. The low-temperature thermosetting resin composition according to claim 1, wherein: The alicyclic epoxy resin is selected from 2-(3,4-epoxycyclohexyl-5,5-spiro-3,4-epoxy)cyclohexane-dioxane, 3,4-epoxy-1-methylcyclohexyl-3,4-epoxy-1-methylhexane carboxylate, 3,4-epoxy-3-methylcyclohexylmethyl-3,4-epoxy-3-methylcyclohexane carboxylate, 3,4-epoxy-5-methylcyclohexylmethyl-3,4-epoxy-5-methylcyclohexane At least one of carboxylic acid ester, 3,4-epoxy-6-methylcyclohexyl carboxylate, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, 6-methyl-3,4-epoxycyclohexylmethyl-6-methyl-3,4-epoxycyclohexanecarboxylate, ethylene bis(3,4-epoxycyclohexanecarboxylate), dicyclopentadiepoxide, bis(3,4-epoxycyclohexylmethyl)adipate, and methylene bis(3,4-epoxycyclohexane).

6. The low-temperature thermosetting resin composition according to claim 1 or 5, wherein The content of the alicyclic epoxy resin accounts for 10 wt % to 60 wt % of the low-temperature thermosetting resin composition.

7. The low-temperature thermosetting resin composition according to claim 6, wherein The content of the alicyclic epoxy resin accounts for 20 wt % to 50 wt % of the low-temperature thermosetting resin composition.

8. The low-temperature thermosetting resin composition according to claim 1, wherein The film-forming additive component includes epoxy resin or phenoxy resin which is solid at room temperature.

9. The low-temperature thermosetting resin composition according to claim 8, wherein The epoxy resin is selected from at least one of bisphenol epoxy resin, novolac epoxy resin, naphthalene epoxy resin and biphenyl epoxy resin; The phenoxy resin is selected from at least one of fluorene-type phenoxy resin, bisphenol-type phenoxy resin, novolac-type phenoxy resin, naphthalene-type phenoxy resin and biphenyl-type phenoxy resin.

10. The low-temperature thermosetting resin composition according to claim 1, 8 or 9, wherein The content of the film-forming additive component accounts for 10 wt % to 70 wt % of the low-temperature thermosetting resin composition.

11. The low-temperature thermosetting resin composition according to claim 10, wherein The content of the film-forming additive component accounts for 20% to 50% by weight of the low-temperature thermosetting resin composition.

12. The low-temperature thermosetting resin composition according to claim 1, wherein The conductive particles are selected from at least one of nickel, cobalt, silver, copper, gold, palladium, solder, and metal-plated resin particles.

13. The low-temperature thermosetting resin composition according to claim 12, wherein The content of the conductive particles is 50 to 100,000 or less per mm 2 Conductive film.

14. The low-temperature thermosetting resin composition according to claim 13, wherein The content of the conductive particles is 200-70,000 particles / mm 2 Conductive film. 15 . An anisotropic conductive film, produced by thermally curing the low-temperature thermosetting resin composition according to claim 1 .

16. The anisotropic conductive film according to claim 15, wherein The thermal curing temperature is 140-150° C., and the curing time is within 5 seconds. 17 . A connection structure, wherein a first electronic component and a second electronic component are anisotropically conductively connected using the anisotropic conductive film according to claim 15 or 16 .

Images