TWI443175B - An anisotropic conductive material, a connecting structure, and a connecting structure - Google Patents

Description

Anisotropic conductive material, connection structure, and manufacturing method of connection structure

The present invention relates to an anisotropic conductive material, a connection structure using the anisotropic conductive material, and a method of manufacturing a connection structure, the anisotropic conductive material comprising a plurality of conductive particles, and for example, for flexible Electrical connection between electrodes of various connection target members such as a printed circuit board, a glass substrate, and a semiconductor wafer.

Anisotropic conductive materials such as an anisotropic conductive paste, an anisotropic conductive ink, and an anisotropic conductive adhesive are widely known. The anisotropic conductive material is a plurality of conductive particles dispersed in a slurry, an ink or a resin.

The anisotropic conductive material is used, for example, for connection between a flexible printed circuit board and a glass substrate (FOG (Film on Glass)), and a connection between a semiconductor wafer and a flexible printed circuit board (COF (Chip on Film) Flip chip)) or a connection between a semiconductor wafer and a glass substrate (COG (Chip on Glass)).

As an example of the above-mentioned anisotropic conductive material, Patent Document 1 below discloses an epoxy resin, rubbery polymer particles, a thermally active latent epoxy curing agent, high softening point polymer particles, and conductive particles. Anisotropic conductive material.

Further, in the following Patent Document 2, it is disclosed that when the viscosity at 25 ° C and 2.5 pm is η1, 25 ° C, and the viscosity at 20 rpm is η 2 , the inversion of the following formulas (A) and (B) is satisfied. Conductive adhesive.

50 Pa‧s≦η2≦200 Pa‧s ...(A)

1.5≦η1/η2≦4.3 Equation (B)

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2000-345010

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2003-064330

When the electrode of the semiconductor wafer and the electrode of the glass substrate are electrically connected by the anisotropic conductive material, an anisotropic conductive material containing conductive particles is disposed on the glass substrate. Next, a semiconductor wafer is laminated to perform heating and pressurization. Thereby, the anisotropic conductive material is hardened, and the electrodes are electrically connected via the conductive particles to obtain a bonded structure.

The prior anisotropic conductive material described in Patent Documents 1 and 2 is applied to an anisotropic conductive material and an anisotropic conductive material applied to a glass substrate during electrical connection between the electrodes. The conductive particles contained may flow greatly before hardening. Therefore, there is a case where the cured layer and the conductive particles formed of the anisotropic conductive material cannot be disposed in a specific region. Further, there is a case where conductive particles are not disposed between the upper and lower electrodes to be connected, or adjacent electrodes which are not to be connected are electrically connected via a plurality of conductive particles. Therefore, there is a case where the conduction reliability of the resulting connection structure is low.

An object of the present invention is to provide an anisotropic conductive material, a connection structure using the anisotropic conductive material, and a method for producing a connection structure, wherein the anisotropic conductive material contains conductive particles and is used between electrodes In the case of electrical connection, the conduction reliability can be improved.

According to a broad aspect of the present invention, an anisotropic conductive material comprising a curable compound, a thermosetting agent, a photohardening initiator, and conductive particles is provided, and the content of the conductive particles is 1 to 19 by weight. Within the range of %.

In a specific aspect of the anisotropic conductive material of the present invention, the curable compound contains an episulfide compound.

In another specific aspect of the anisotropic conductive material of the present invention, the curable compound contains a curable compound having at least one of an epoxy group and a cyclothioethyl group and a (meth) acrylonitrile group.

The anisotropic conductive material of the present invention preferably has a viscosity at 25 ° C and 2.5 rpm in the range of 20 to 200 Pa ‧ s.

In other specific aspects of the anisotropic conductive material of the present invention, the light is hardened by irradiation of light, and the viscosity after B-staged is in the range of 2000 to 3500 Pa‧s.

In the anisotropic conductive material of the present invention, it is preferred that when the viscosity at 25 ° C and 2.5 rpm is η1 and the viscosity at 25 ° C and 5 rpm is η 2 , the above η 2 is 20 Pa‧s or more, 200. Below Pa‧s, the ratio (η1/η2) of the above η1 to the above η2 is 0.9 or more and 1.1 or less.

In another specific aspect of the anisotropic conductive material of the present invention, the curable compound contains a crystalline compound.

The connection structure according to the present invention includes a first connection target member, a second connection target member, and a connection portion electrically connecting the first and second connection target members, and the connection portion is configured by the present invention. The anisotropic conductive material is formed by hardening.

Further, according to a broader aspect of the present invention, a method of manufacturing a connection structure is provided, comprising the steps of: coating an anisotropic conductive material on a surface of a first connection member to form an anisotropic conductive material layer; And hardening the anisotropic conductive material layer by irradiating the anisotropic conductive material layer, and the B-order of the anisotropic conductive material layer is formed in a viscosity of 2000 to 3500 Pa‧s. And forming a second connection member on the upper surface of the B-staged anisotropic conductive material layer; and using the curable compound, the thermosetting agent, the photohardening initiator, and the anisotropic conductive material; The conductive particles and the content of the conductive particles are an anisotropic conductive material in a range of 1 to 19% by weight.

Since the anisotropic conductive material of the present invention contains a curable compound, a thermosetting agent, a photocuring initiator, and conductive particles, the anisotropic conductive material can be cured by irradiation of light and heating. For example, the anisotropic conductive material may be hard-hardened or photohardened by irradiation or heating of light, whereby the anisotropic conductive material is cured. Therefore, by irradiating light or imparting heat to the anisotropic conductive material at an appropriate timing after coating, the flow of the anisotropic conductive material and the conductive particles contained in the anisotropic conductive material can be suppressed. Therefore, the cured layer and the conductive particles formed of the anisotropic conductive material can be disposed in a specific region.

Further, the anisotropic conductive material of the present invention contains a curable compound, a thermosetting agent, a photocuring initiator, and conductive particles, and the content of the conductive particles is in the range of 1 to 19% by weight. When the electrodes are electrically connected, the conduction reliability can be improved. For example, the conductive particles can be easily connected between the upper and lower electrodes to be connected, and the adjacent electrodes that should not be connected can be prevented from being connected via a plurality of conductive particles.

In the method for producing a connection structure according to the present invention, the anisotropic conductive material layer is cured by irradiating light to the anisotropic conductive material layer, and the viscosity is in a range of 2000 to 3500 Pa‧s. Since the anisotropic conductive material layer is B-staged, the flow of the conductive particles contained in the anisotropic conductive material layer and the anisotropic conductive material layer can be suppressed. Therefore, the cured layer and the conductive particles formed of the anisotropic conductive material can be disposed in a specific region. Therefore, when the electrodes of the first and second connection target members are electrically connected to each other, the conduction reliability can be improved. For example, the conductive particles can be easily connected between the upper and lower electrodes to be connected, and the adjacent electrodes that should not be connected can be prevented from being connected via a plurality of conductive particles.

Hereinafter, the present invention will be described in detail.

The anisotropic conductive material of the present invention contains a curable compound, a thermosetting agent, a photocuring initiator, and conductive particles. In 100% by weight of the anisotropic conductive material of the present invention, the content of the conductive particles is in the range of 1 to 19% by weight.

First, each component contained in the anisotropic conductive material of the present invention will be described in detail.

(hardening compound)

The curable compound is not particularly limited. As the curable compound, a previously known curable compound can be used. The curable compound may be used alone or in combination of two or more.

Examples of the curable compound include light, a thermosetting compound, a photocurable compound, and a thermosetting compound. The above-mentioned light and thermosetting compound have photocurability and thermosetting property. The photocurable compound has, for example, photocurability and does not have thermosetting properties. The above thermosetting compound does not have photocurability, for example, and has thermosetting properties.

The curable compound contains a light and a thermosetting compound, or a photocurable compound and a thermosetting compound. In the case where the curable compound contains the light and the thermosetting compound, the curable compound may not contain at least one of the photocurable compound and the thermosetting compound, and may be in addition to the light and thermosetting compound. Further, at least one of a photocurable compound and a thermosetting compound is contained. When the curable compound does not contain the light or thermosetting compound, the curable compound contains a photocurable compound and a thermosetting compound.

The curable compound preferably contains at least one of the light and thermosetting compound, the photocurable compound, and the thermosetting compound, or contains photohardening, from the viewpoint of easily controlling the curing of the anisotropic conductive material. Compounds and thermosetting compounds. More preferably, the curable compound contains a photocurable compound and a thermosetting compound.

The curable compound is not particularly limited. Examples of the curable compound include an epoxy compound, an episulfide compound, a (meth)acrylic compound, a phenol compound, an amine compound, an unsaturated polyester compound, a polyurethane compound, and a polyoxonium compound. And polyimine compounds and the like. The above (meth)acrylic acid means acrylic acid or methacrylic acid.

When the photocurable compound and the thermosetting compound are used in combination, the amount of the photocurable compound and the thermosetting compound to be used is appropriately adjusted depending on the type of the photocurable compound and the thermosetting compound. The anisotropic conductive material of the present invention preferably contains a photocurable compound and a thermosetting compound in a weight ratio of 1:99 to 90:10, more preferably 5:95 to 60:40, and further It is preferably contained in the range of 20:80 to 40:60.

From the viewpoint of easily controlling the above η2 and the above ratio (η1/η2) within the above range, the curable compound preferably contains a crystalline resin.

The crystalline resin is not particularly limited as long as it has crystallinity. Examples of the above-mentioned crystalline resin include a resin having a functional group having light and thermosetting properties as described above in a naphthalene skeleton structure, and a resin having a functional group having light and thermosetting properties in a resorcin skeleton structure.

In view of the fact that the above-mentioned η2 and the above ratio (η1/η2) are controlled within the above range, the lower limit of the content of the crystalline resin in 100 parts by weight of the curable compound is preferably 80 parts by weight, more preferably The lower limit is 90 parts by weight.

[thermosetting compound]

The curable compound preferably contains an epoxy compound and an episulfide compound (a compound containing an episulfide group) from the viewpoint of easily controlling the hardening of the anisotropic conductive material or further improving the conduction reliability of the bonded structure. At least one of them is more preferably an episulfide compound. From the viewpoint of improving the hardenability of the anisotropic conductive material, a preferred lower limit of the content of the above-mentioned episulfide compound is 10 parts by weight, and a lower limit is 20 parts by weight, preferably a lower limit, in 100 parts by weight of the curable compound. It is 50 parts by weight, and the upper limit is 40 parts by weight.

The epoxy compound and the above episulfide compound preferably each have an aromatic ring. Examples of the aromatic ring include a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, and a tetracene ring. Ring, extended triphenyl ring, tetrafen ring, anthracene ring, pentacene ring, anthracene ring and anthracene ring. Among them, the above aromatic ring is preferably a benzene ring, a naphthalene ring or an anthracene ring, more preferably a benzene ring or a naphthalene ring.

The episulfide compound has an episulfide group instead of an epoxy group, and thus can be rapidly hardened at a low temperature. That is, the episulfide compound having an episulfide group can be hardened at a lower temperature due to the episulfide group than the epoxy compound having an epoxy group.

The above-mentioned episulfide compound preferably has a structure represented by the following formula (1), (2), (5), (7) or (8) from the viewpoint of hardening at a lower temperature, and more preferably Preferably, it has a structure represented by the following formula (1) or (2).

[Chemical 1]

In the above formula (1), R1 and R2 each represent an alkylene group having 1 to 5 carbon atoms, and 2 to 4 of the 4 groups of R3, R4, R5 and R6 represent hydrogen, and R3, R4, R5 and R6 are The group which is not hydrogen represents a group represented by the following formula (3).

The four groups of R3, R4, R5 and R6 in the above formula (1) may all be hydrogen. One or two of the four groups of R3, R4, R5 and R6 are a group represented by the following formula (3), and the four groups of R3, R4, R5 and R6 are not the following formula (3). The base of the group shown may be hydrogen.

[Chemical 2]

In the above formula (3), R7 represents an alkylene group having 1 to 5 carbon atoms.

[Chemical 3]

In the above formula (2), R51 and R52 each represent an alkylene group having 1 to 5 carbon atoms, and 4 to 6 of the 6 groups of R53, R54, R55, R56, R57 and R58 represent hydrogen, and R53, R54, The group other than hydrogen in R55, R56, R57 and R58 represents a group represented by the following formula (4).

The six groups of R53, R54, R55, R56, R57 and R58 in the above formula (2) may all be hydrogen. One or two of the six groups of R53, R54, R55, R56, R57 and R58 are a group represented by the following formula (4), and R53, R54, R55, R56, R57 and R58 are not the following formulas. The group of the group shown in (4) may be hydrogen.

[Chemical 4]

In the above formula (4), R59 represents an alkylene group having 1 to 5 carbon atoms.

[Chemical 5]

In the above formula (5), R101 and R102 each represent an alkylene group having 1 to 5 carbon atoms. 6 to 8 of the 8 groups of R103, R104, R105, R106, R107, R108, R109 and R110 represent hydrogen.

Among the R103, R104, R105, R106, R107, R108, R109 and R110 in the above formula (5), a group other than hydrogen represents a group represented by the following formula (6). The eight groups of R103, R104, R105, R106, R107, R108, R109 and R110 may all be hydrogen. One or two of the eight groups of R103, R104, R105, R106, R107, R108, R109 and R110 are a group represented by the following formula (6), and R103, R104, R105, R106, R107, R108, The group of the group represented by the following formula (6) in R109 and R110 may be hydrogen.

[Chemical 6]

In the above formula (6), R111 represents an alkylene group having 1 to 5 carbon atoms.

[Chemistry 7]

In the above formula (7), R1 and R2 each represent an alkylene group having 1 to 5 carbon atoms.

[化8]

In the above formula (8), R3 and R4 represent an alkylene group having 1 to 5 carbon atoms.

The episulfide compound having the structure represented by the above formula (1) or (2) has at least two cyclic thioethyl groups (cyclothio groups). Further, a group having an episulfide group is bonded to a benzene ring or a naphthalene ring. With such a structure, the anisotropic conductive material can be rapidly hardened at a low temperature by heating the anisotropic conductive material. In the present specification, the term "low temperature" means a temperature of 200 ° C or lower.

An episulfide compound having a structure represented by the above formula (1), (2), (5), (7) or (8) and the above formula (1), (2), (5), (7) or (8) In the case where the thioethyl group of the ring is an epoxy group, the reactivity is higher. The reason is that the cyclothioethyl group is more susceptible to ring opening than the epoxy group, and the reactivity is higher. Since the reactivity of the episulfide compound having the structure represented by the above formula (1), (2), (5), (7) or (8) is high, the anisotropic conductive material can be rapidly cured at a low temperature. In particular, the reactivity of the episulfide compound having the structure represented by the above formula (1) or (2) is relatively high, so that the anisotropic conductive material can be rapidly hardened at a low temperature.

R1 and R2 in the above formula (1), R51 and R52 in the above formula (2), R7 in the above formula (3), R59 in the above formula (4), R101 in the above formula (5), and R102, R111 in the above formula (6), R1 and R2 in the above formula (7), and R3 and R4 in the above formula (8) are an alkylene group having 1 to 5 carbon atoms. When the carbon number of the alkylene group exceeds 5, the curing rate of the above-mentioned episulfide compound tends to be slow.

R1 and R2 in the above formula (1), R51 and R52 in the above formula (2), R7 in the above formula (3), R59 in the above formula (4), R101 in the above formula (5), and R102, R111 in the above formula (6), R1 and R2 in the above formula (7), and R3 and R4 in the above formula (8) are each preferably an alkylene group having 1 to 3 carbon atoms, more preferably It is a methylene group. The above alkylene group may be an alkylene group having a linear structure or an alkylene group having a branched structure.

The structure shown in the above (1) is preferably a structure represented by the following formula (1A). The episulfide compound having a structure represented by the following formula (1A) is excellent in hardenability.

[Chemistry 9]

In the above formula (1A), R1 and R2 each represent an alkylene group having 1 to 5 carbon atoms.

The structure represented by the above formula (1) is more preferably a structure represented by the following formula (1B). The episulfide compound having a structure represented by the following formula (1B) is more excellent in hardenability.

[化10]

The structure shown in the above (2) is preferably a structure represented by the following formula (2A). The episulfide compound having a structure represented by the following formula (2A) is excellent in hardenability.

[11]

In the above formula (2A), R51 and R52 each represent an alkylene group having 1 to 5 carbon atoms.

The structure represented by the above formula (2) is more preferably a structure represented by the following formula (2B). The episulfide compound having a structure represented by the following formula (2B) is more excellent in hardenability.

[化12]

The epoxy compound is not particularly limited. As the epoxy compound, a previously known epoxy compound can be used. The epoxy compound may be used alone or in combination of two or more.

Examples of the epoxy compound include a phenoxy resin having an epoxy group, a bisphenol F type epoxy resin, a bisphenol S type epoxy resin, a phenol novolak type epoxy resin, a biphenol type epoxy resin, and naphthalene. Epoxy resin, bismuth epoxy resin, phenol aralkyl epoxy resin, naphthol aralkyl epoxy resin, dicyclopentadiene epoxy resin, fluorene epoxy resin, adamantane skeleton Epoxy resin, epoxy resin having a tricyclodecane skeleton, and three in the skeleton Nuclear epoxy resin, etc.

Specific examples of the epoxy compound include a bisphenol type derived from epichlorohydrin, a bisphenol A epoxy resin, a bisphenol F epoxy resin, or a bisphenol D epoxy resin. Epoxy resin, and epoxy novolac resin derived from epichlorohydrin and phenol novolac or cresol novolac. Various epoxy compounds having two or more epoxy groups in one molecule such as glycidylamine, glycidyl ester, and alicyclic or heterocyclic formula can also be used.

The curable compound may further contain an epoxy having a structure in which an epoxy group in the structure represented by the above formula (1), (2), (5), (7) or (8) is substituted with an epoxy group. Compound. In this case, the structures represented by the above formulas (3), (4) and (6) are also preferably a structure in which an episulfide group is substituted with an epoxy group. The curable compound may further contain an epoxy compound represented by the following formula (11) or (12). The curable compound preferably contains an episulfide compound represented by the above formula (1) or (2) and an epoxy compound represented by the following formula (11) or (12).

[Chemistry 13]

In the above formula (11), R11 and R12 each represent an alkylene group having 1 to 5 carbon atoms, and 2 to 4 of the four groups of R13, R14, R15 and R16 represent hydrogen, and R13, R14, R15 and R16 are The group which is not hydrogen represents a group represented by the following formula (13).

The four groups of R13, R14, R15 and R16 in the above formula (11) may all be hydrogen. One or two of the four groups of R13, R14, R15 and R16 are a group represented by the following formula (13), and the four groups of R13, R14, R15 and R16 are not the following formula (13). The base of the group shown may be hydrogen.

[Chemistry 14]

In the above formula (13), R17 represents an alkylene group having 1 to 5 carbon atoms.

[化15]

In the above formula (12), R61 and R62 each represent an alkylene group having 1 to 5 carbon atoms, and 4 to 6 of the 6 groups of R63, R64, R65, R66, R67 and R68 represent hydrogen, and R63 and R64. The group other than hydrogen in R65, R66, R67 and R68 represents a group represented by the following formula (14).

The six groups of R63, R64, R65, R66, R67 and R68 in the above formula (12) may all be hydrogen. One or two of the six groups of R63, R64, R65, R66, R67 and R68 are a group represented by the following formula (14), and six groups of R63, R64, R65, R66, R67 and R68 are The group which is not a group represented by the following formula (14) may be hydrogen.

[Chemistry 16]

In the above formula (14), R69 represents an alkylene group having 1 to 5 carbon atoms.

R11 and R12 in the above formula (11), R61 and R62 in the above formula (12), R17 in the above formula (13), and R69 in the above formula (14) are alkylene groups having 1 to 5 carbon atoms. . When the carbon number of the alkylene group exceeds 5, the curing rate of the epoxy compound represented by the above formula (11) or (12) tends to be slow.

R11 and R12 in the above formula (11), R61 and R62 in the above formula (12), R17 in the above formula (13), and R69 in the above formula (14) are preferably each having 1 to 3 carbon atoms. The alkyl group is more preferably a methylene group. The above alkylene group may be an alkylene group having a linear structure or an alkylene group having a branched structure.

The structure shown in the above (11) is preferably a structure represented by the following formula (11A). An epoxy compound having a structure represented by the following formula (11A) is commercially available and can be easily obtained.

[化17]

In the above formula (11A), R11 and R12 each represent an alkylene group having 1 to 5 carbon atoms.

The structure represented by the above formula (11) is more preferably a structure represented by the following formula (11B). The epoxy compound having a structure represented by the following formula (11B) is resorcinol diglycidyl ether. Resorcinol diglycidyl ether is commercially available and is readily available.

[化18]

The structure represented by the above formula (12) is preferably a structure represented by the following formula (12A). An epoxy compound having a structure represented by the following formula (12A) can be easily obtained.

[Chemistry 19]

In the above formula (12A), R61 and R62 each represent an alkylene group having 1 to 5 carbon atoms.

The structure represented by the above formula (12) is more preferably a structure represented by the following formula (12B). An epoxy compound having a structure represented by the following formula (12B) can be easily obtained.

[Chemistry 20]

100% by weight of the mixture of the episulfide compound having the structure represented by the above formula (1) or (2) and the epoxy compound represented by the above formula (11) or (12) (hereinafter, simply referred to as the mixture A) Preferably, the content of the episulfide compound having the structure represented by the above formula (1) or (2) is 10 to 50% by weight, and the content of the epoxy compound represented by the above formula (11) or (12) is preferable. The content of the episulfide compound having the structure represented by the above formula (1) or (2) is preferably from 20 to 30% by weight, and is represented by the above formula (11) or (12). The content of the epoxy compound is 80 to 70% by weight.

When the content of the episulfide compound having the structure represented by the above formula (1) or (2) is too small, the curing rate of the above-mentioned mixture A tends to be slow. When the content of the episulfide compound having the structure represented by the above formula (1) or (2) is too large, the viscosity of the above mixture A may become too high, or the above-mentioned mixture A may become a solid.

The method for producing the above mixture A is not particularly limited. As the production method, for example, a method of producing an epoxy compound represented by the above formula (11) or (12) and converting a part of the epoxy compound into an epoxy group can be mentioned.

In the method of producing the mixture A, it is preferred to continuously or intermittently add the epoxy compound represented by the above formula (11) or (12) or the solution containing the epoxy compound to the first solution containing the vulcanizing agent. Further, a method of adding a second solution containing a vulcanizing agent continuously or intermittently. By this method, a part of the epoxy group of the above epoxy compound can be converted into an episulfide group. As a result, the above mixture A can be obtained. Examples of the vulcanizing agent include thiocyanates, thioureas, phosphine sulfide, dimethylthiocarbamide, and N-methylbenzothiazole-2-thione. Examples of the thiocyanate include sodium thiocyanate, potassium thiocyanate, and sodium thiocyanate.

The curable compound may further contain a monomer having an epoxy compound having a structure represented by the following formula (21), a polymer obtained by bonding at least two of the epoxy compounds, or the monomer and the polymer. a mixture.

[Chem. 21]

In the above formula (21), R1 represents an alkylene group having 1 to 5 carbon atoms, R2 represents an alkylene group having 1 to 5 carbon atoms, and R3 represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or the following formula (22) In the structure shown, R4 represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a structure represented by the following formula (23).

[化22]

In the above formula (22), R5 represents an alkylene group having 1 to 5 carbon atoms.

[化23]

In the above formula (23), R6 represents an alkylene group having 1 to 5 carbon atoms.

The epoxy compound having the structure represented by the above formula (21) is characterized by having an unsaturated double bond and at least two epoxy groups. By using the epoxy compound having the structure represented by the above formula (21), the anisotropic conductive material can be rapidly hardened at a low temperature.

The curable compound may further contain a monomer having a compound represented by the following formula (31), a polymer obtained by bonding at least two of the compounds, or a mixture of the monomer and the polymer.

[Chem. 24]

In the above formula (31), R1 represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms or a structure represented by the following formula (32), R2 represents an alkylene group having 1 to 5 carbon atoms, and R3 represents a carbon number of 1 to 5; An alkyl group of 5, X1 represents an oxygen atom or a sulfur atom, and X2 represents an oxygen atom or a sulfur atom.

[化25]

In the above formula (32), R4 represents an alkylene group having 1 to 5 carbon atoms, and X3 represents an oxygen atom or a sulfur atom.

The epoxy compound corresponding to the compound having the structure represented by the above formula (31) can be synthesized, for example, in the following manner.

The hydrazine compound having a hydroxyl group, epichlorohydrin, sodium hydroxide, and methanol as a raw material compound are mixed, and cooled and reacted. Thereafter, an aqueous sodium hydroxide solution was added dropwise. After the dropwise addition, the mixture was further reacted to obtain a reaction liquid. Next, water and toluene were added to the reaction liquid, and the toluene layer was taken out. After washing the toluene layer with water, it is dried to remove water and solvent. Thus, an epoxy compound corresponding to the compound having the structure represented by the above formula (31) can be easily obtained. Further, the hydrazine compound having a hydroxyl group as a raw material compound is commercially available, for example, from JFE Chemical Co., Ltd. or the like.

Further, the cyclic thioethyl group-containing compound corresponding to the compound having the structure represented by the above formula (31) can be converted into an epoxy group of an epoxy compound corresponding to the compound having the structure represented by the above formula (31). Synthetic by thioethyl group. For example, after adding a solution containing an epoxy compound or a compound as a raw material compound to a solution containing the above-mentioned vulcanizing agent, a solution containing the above vulcanizing agent is further added, whereby an epoxy group can be easily converted into an episulfide group. Ethyl.

The curable compound may also contain an epoxy compound having a hetero ring containing a nitrogen atom. The epoxy compound having a hetero ring containing a nitrogen atom is preferably an epoxy compound represented by the following formula (41) or an epoxy compound represented by the following formula (42). By using such a curable compound, the curing speed of the anisotropic conductive material can be further accelerated, and the heat resistance of the cured product of the anisotropic conductive material can be further improved.

[Chem. 26]

In the above formula (41), R1 to R3 each represent an alkylene group having 1 to 5 carbon atoms, and Z represents an epoxy group or a hydroxymethyl group. R21~R23 can be the same or different.

[化27]

In the above formula (42), R1 to R3 each represent an alkylene group having 1 to 5 carbon atoms, p, q and r each represent an integer of 1 to 5, and R4 to R6 each represent an alkylene group having 1 to 5 carbon atoms. R1~R3 can be the same or different. p, q and r may be the same or different. R4~R6 can be the same or different.

The above epoxy compound having a hetero ring containing a nitrogen atom is preferably triglycidyl isocyanurate or trishydroxyethyl isocyanurate triglycidyl ether. By using these hardening compounds, the hardening speed of the anisotropic conductive material can be further accelerated.

The above curable compound preferably contains an epoxy compound having an aromatic ring. By using an epoxy compound having an aromatic ring, the hardening speed of the anisotropic conductive material can be further accelerated, and the anisotropic conductive material can be easily coated. From the viewpoint of further improving the coatability of the anisotropic conductive material, the above aromatic ring is preferably a benzene ring, a naphthalene ring or an anthracene ring. Examples of the epoxy compound having the above aromatic ring include resorcinol diglycidyl ether or 1,6-naphthalene diglycidyl ether. Among them, particularly preferred is a benzenediol diglycidyl ether having a structure represented by the above formula (11B). By using resorcinol diglycidyl ether, the rate of hardening of the anisotropic conductive material can be accelerated, and the anisotropic conductive material can be easily coated.

[Photocurable compound]

The curable compound of the present invention may also contain a photocurable compound so as to be hardened by irradiation of light. The curable compound can be semi-cured by irradiation of light, and the fluidity of the curable compound can be lowered.

The photocurable compound is not particularly limited, and examples thereof include a (meth)acrylic resin and a cyclic ether group-containing resin.

As the (meth)acrylic resin, for example, an ester compound obtained by reacting (meth)acrylic acid with a compound having a hydroxyl group, and an epoxy group obtained by reacting (meth)acrylic acid with an epoxy compound (methyl group) can be suitably used. An acrylate, a (meth)acrylic acid urethane obtained by reacting an isocyanate with a (meth)acrylic acid derivative having a hydroxyl group.

In the case of containing a photocurable compound other than the photocurable compound, the photocurable compound may be a crosslinkable compound or a non-crosslinkable compound.

Specific examples of the crosslinkable compound include 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, and 1,9-fluorene. Alcohol di(meth)acrylate, (poly)ethylene glycol di(meth)acrylate, (poly)propylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, pentaerythritol di Methyl) acrylate, glycerin methacrylate acrylate, pentaerythritol tri(meth) acrylate, trimethylolpropane trimethacrylate, allyl (meth) acrylate, vinyl (meth) acrylate , divinylbenzene, polyester (meth) acrylate, and (meth) acrylate urethane.

Specific examples of the non-crosslinkable compound include ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, and n-butyl (meth)acrylate. Isobutyl methacrylate, tert-butyl (meth)acrylate, amyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, (meth)acrylic acid-2- Ethylhexyl ester, n-octyl (meth)acrylate, isooctyl (meth)acrylate, decyl (meth)acrylate, decyl (meth)acrylate, undecyl (meth)acrylate, Dodecyl (meth)acrylate, tridecyl (meth)acrylate, and tetradecyl (meth)acrylate.

[Light and thermosetting compounds]

When the curable compound contains, for example, a thermosetting compound and a photopolymerizable compound, the curable compound is easily controlled from the viewpoint of curing the anisotropic conductive material or further improving the conduction reliability of the bonded structure. It is preferred to contain light and a thermosetting compound having at least one of an epoxy group and a cyclothioethyl group and a (meth)acryl fluorenyl group. The curable compound preferably contains light having an epoxy group and a (meth) acrylonitrile group and a thermosetting compound (hereinafter also referred to as a partially (meth) acrylated epoxy resin). The above (meth) acrylonitrile group means an acryl fluorenyl group or a methacryl fluorenyl group. The above (meth) acrylate means acrylate or methacrylate.

The above-mentioned partial (meth) acrylated epoxy resin is obtained, for example, by reacting an epoxy resin with (meth)acrylic acid in the presence of a basic catalyst according to a usual method. It is preferred to convert 20% or more of the epoxy group to a (meth) acrylonitrile group (conversion ratio) and partially (meth) acrylate. More preferably, 50% of the epoxy group is converted to a (meth) acrylonitrile group.

From the viewpoint of improving the hardenability of the anisotropic conductive material, a preferred lower limit of the content of the partial (meth)acrylated epoxy resin in 100% by weight of the curable compound is 0.1% by weight, and a lower limit is preferred. It is 0.5% by weight, a preferred upper limit is 2% by weight, and a more preferred upper limit is 1.5% by weight.

Examples of the epoxy (meth) acrylate include bisphenol epoxy (meth) acrylate, cresol novolak epoxy (meth) acrylate, and carboxylic anhydride modified epoxy (meth) acrylate. Ester, and phenol novolak type epoxy (meth) acrylate, etc.

(hot hardener)

The above thermal curing agent is not particularly limited. As the above-mentioned heat hardener, a previously known heat hardener can be used. Examples of the above-mentioned thermosetting agent include an imidazole curing agent, an amine curing agent, a phenol curing agent, a polythiol curing agent, and an acid anhydride. These thermosetting agents may be used alone or in combination of two or more.

The above-mentioned thermosetting agent is preferably an imidazole hardener, a polythiol hardener or an amine hardener because the anisotropic conductive material can be hardened more rapidly at a low temperature. Further, a latent hardener is preferred because the storage stability of the anisotropic conductive material can be improved. The latent hardener is preferably a latent imidazole hardener, a latent polythiol hardener or a latent amine hardener. The above-mentioned thermosetting agent may be coated with a polymer material such as a polyurethane resin or a polyester resin.

The imidazole curing agent is not particularly limited, and examples thereof include 2-methylimidazole, 2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, and 1-cyanoethyl-2- Phenyl imidazolium trimellitate, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-all three And 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-all three An isocyanuric acid addition product or the like.

The polythiol curing agent is not particularly limited, and examples thereof include trimethylolpropane tri-3-mercaptopropionate, pentaerythritol tetrakis-3-mercaptopropionate, and dipentaerythritol hexa-3-mercaptopropionate. .

The amine curing agent is not particularly limited, and examples thereof include hexamethylenediamine, octamethylenediamine, decamethylenediamine, and 3,9-bis(3-aminopropyl)-2. 4,8,10-tetraspiro[5.5]undecane, bis(4-aminocyclohexyl)methane, m-phenylenediamine, and diaminodiphenylphosphonium.

The content of the above-mentioned thermosetting agent is not particularly limited. The lower limit of the content of the above-mentioned thermosetting agent is preferably 5 parts by weight, more preferably 10 parts by weight, more preferably 30 parts by weight, even more preferably 20 parts by weight, based on 100 parts by weight of the total of the curable compound. . When the content of the above-mentioned thermosetting agent satisfies the above-mentioned preferable lower limit and upper limit, the anisotropic conductive material can be sufficiently thermally cured.

(photohardening initiator)

The photohardening initiator is not particularly limited. As the photohardening initiator, a previously known photohardening initiator can be used. The photohardening initiator may be used alone or in combination of two or more.

The photocuring initiator is not particularly limited, and examples thereof include an acetophenone photohardening initiator, a benzophenone photohardening initiator, and 9-oxosulfuric acid. , ketal photohardening initiator, halogenated ketone, fluorenylphosphine oxide and guanidinophosphate.

Specific examples of the acetophenone photohardening initiator include 4-(2-hydroxyethoxy)phenyl (2-hydroxy-2-propyl) ketone and 2-hydroxy-2-methyl-1. -Phenylpropan-1-one, methoxyacetophenone, 2,2-dimethoxy-1,2-diphenylethan-1-one, and 2-hydroxy-2-cyclohexylacetophenone Wait. Specific examples of the ketal photohardening initiator include benzoin dimethyl ketal and the like.

The content of the photohardening initiator is not particularly limited. The lower limit of the content of the photohardening initiator is 0.1 part by weight, more preferably 0.2 part by weight, more preferably 2 parts by weight, and even more preferably 1 upper limit, based on 100 parts by weight of the total of the curable compound. Parts by weight. When the content of the photohardening initiator is such that the above lower limit and upper limit are satisfied, the anisotropic conductive material can be appropriately photocured. By irradiating the anisotropic conductive material with light to be B-staged, the flow of the anisotropic conductive material can be suppressed. Further, by irradiating the anisotropic conductive material with light to be semi-hardened, the flow of the anisotropic conductive material can be suppressed.

(conductive particles)

As the conductive particles contained in the anisotropic conductive material of the present invention, for example, previously known conductive particles which can electrically connect the electrodes are used. The conductive particles are preferably particles having a conductive layer on the outer surface. The conductive particles may have insulating particles attached to the surface of the conductive layer, or the surface of the conductive layer may be covered with an insulating layer. In this case, the insulating particles or the insulating layer are removed by pressurization at the time of connection of the electrodes.

Examples of the conductive particles include conductive particles coated with a conductive layer on the surface of organic particles, inorganic particles, organic-inorganic hybrid particles, or metal particles, and metal particles substantially composed only of a metal. The above conductive layer is not particularly limited. Examples of the conductive layer include a gold layer, a silver layer, a copper layer, a nickel layer, a palladium layer, and a conductive layer containing tin.

In 100% by weight of the anisotropic conductive material, the content of the conductive particles is in the range of 1 to 19% by weight. A preferred lower limit of the content of the above conductive particles is 5% by weight, a preferred upper limit is 15% by weight, and a more preferred upper limit is 10% by weight. When the content of the conductive particles is in the above range, the conductive particles can be easily disposed between the lower electrodes to be connected. Further, it is difficult to electrically connect between adjacent electrodes that should not be connected via a plurality of conductive particles. That is, it is possible to prevent a short circuit between adjacent electrodes.

(other ingredients)

The anisotropic conductive material of the present invention may also contain a solvent. The viscosity of the anisotropic conductive material can be easily adjusted by using the solvent. Further, for example, when the curable compound is a solid, the dispersibility of the curable compound can be improved by adding a solvent to the solid curable compound and dissolving it. Examples of the solvent include ethyl acetate, methyl cellosolve, toluene, acetone, methyl ethyl ketone, cyclohexane, n-hexane, tetrahydrofuran, and diethyl ether.

The anisotropic conductive material of the present invention preferably contains an adhesion adjusting agent because the adhesion of the cured product of the anisotropic conductive material can be improved. From the viewpoint of further improving the adhesion, the above-mentioned adhesion adjusting agent is preferably a decane coupling agent.

The anisotropic conductive material of the present invention preferably contains a filler. By using the filler, the latent thermal expansion of the cured product of the anisotropic conductive material can be suppressed.

In order to control the above η2 and the above ratio (η1/η2) within a preferred range, the filler is preferably subjected to surface treatment, and is preferably a hydrophilic filler.

The above filler is not particularly limited. Examples of the filler include cerium oxide, aluminum nitride, and aluminum oxide. These fillers may be used alone or in combination of two or more.

The above-mentioned hydrophilic filler refers to a filler whose surface is covered with a hydrophilic group. Examples of the hydrophilic group include a polar group such as a hydroxyl group, an amine group, a guanamine group, a carboxylate group, and a carboxyl group, and an ionic group such as a carboxylate ion group, a sulfonate ion group, and an ammonium ion group. The hydrophilic filler may be a hydrophilic filler obtained by surface-treating the above-mentioned filler with a hydrophilic surface treatment agent.

Examples of the hydrophilic surface treatment agent include a decane coupling agent, a titanate coupling agent, an aluminum coupling agent, an aluminum zirconium coupling agent, Al ₂ O ₃ , TiO ₂ , ZrO ₂ , polyfluorene oxide, and stearin. Aluminum acid and the like. Among them, as the hydrophilic surface treatment agent, a decane coupling agent can be preferably used.

The content of the above filler is not particularly limited. The lower limit of the content of the filler is preferably 5 parts by weight, more preferably 15 parts by weight, more preferably 70 parts by weight, and still more preferably 50 parts by weight, based on 100 parts by weight of the total of the curable compounds. When the content of the filler satisfies the above preferred lower limit and upper limit, the latent thermal expansion of the cured product of the anisotropic conductive material can be sufficiently suppressed, and the filler can be sufficiently dispersed in the anisotropic conductive material.

(Other details of anisotropic conductive materials)

The method for producing the anisotropic conductive material of the present invention is not particularly limited, and examples thereof include blending the curable compound, the thermosetting agent, the photocuring initiator, the conductive particles, and other components added as needed. A method of thorough mixing using a planetary mixer or the like.

The viscosity of the anisotropic conductive material of the present invention at 25 ° C and 2.5 rpm is preferably in the range of 20 to 200 Pa ‧ s. That is, the viscosity of the anisotropic conductive material before coating at 25 ° C and 2.5 rpm is preferably in the range of 20 to 200 Pa ‧ s. In this case, for example, when an anisotropic conductive material is applied onto a coating member (first connection target member) such as a substrate, the flow of the anisotropic conductive material before curing can be further suppressed. Further, the resin component between the electrode and the conductive particles can be easily removed, and the contact area between the electrode and the conductive particles can be increased. Further, when the surface of the application target member (first connection target member) is uneven, the surface of the unevenness can be sufficiently filled with the anisotropic conductive material, and it is difficult to generate voids after curing. Further, in the anisotropic conductive material, it is difficult to precipitate conductive particles, and the dispersibility of the conductive particles can be improved.

The anisotropic conductive material of the present invention is hardened by irradiation with light, and the viscosity after B-stage (hereinafter sometimes abbreviated as η3') is preferably in the range of 2,000 to 3,500 Pa‧s. From the viewpoint of further suppressing the flow of the anisotropic conductive material layer and the conductive particles, the lower limit of the viscosity η3' is preferably 2250 Pa‧s, and the upper limit is preferably 3250 Pa‧s. A preferred lower limit of the measured temperature of the viscosity η3' is 20 ° C, and a preferred upper limit is 30 ° C. The measurement temperature of the above viscosity η3' is particularly preferably 25 °C.

The anisotropic conductive material of the present invention preferably has a viscosity of η1 at 25 ° C and 2.5 rpm and a viscosity of η 2 at 25 ° C and 5 rpm, and the above η 2 is 20 Pa‧s or more and 200 Pa‧ s is hereinafter, and the ratio (η1/η2) of the above η1 to the above η2 is 0.9 or more and 1.1 or less. That is, the anisotropic conductive material of the present invention preferably satisfies both of the following formulae (X) and (Y).

20 Pa‧s≦η2≦200 Pa‧s ...(X)

0.9≦η1/η2≦1.1 (式)

When the prior anisotropic conductive material described in Japanese Laid-Open Patent Publication No. 2003-064330 is applied to a member to be coated by a dispenser or the like, the coating may not be stably applied. In the anisotropic conductive material exhibiting the viscosity characteristic as described in Patent Document 2, the viscosity may be greatly lowered immediately after the application, and the anisotropic conductive material may be locally applied in a large amount. Therefore, the coating width is not fixed, and as a result, the width or thickness of the cured layer formed of the anisotropic conductive material is liable to be uneven. On the other hand, in the anisotropic conductive material of the present invention, the η2 and the ratio (η1/η2) are within the above-described range, whereby the anisotropic conductive material is applied to the coating by a dispenser or the like. When the member member is used, it can be applied more stably and uniformly. Further, the viscosity is not greatly lowered immediately after the application of the coating, and it is possible to suppress the local application of the anisotropic conductive material in a large amount. Therefore, the coating width can be made fixed, and as a result, the width or thickness of the cured layer formed of the anisotropic conductive material is less likely to cause unevenness.

From the viewpoint of more uniformly coating the anisotropic conductive material, the preferred lower limit of the above η2 is 50 Pa‧s, the lower limit is preferably 100 Pa‧s, and the upper limit is preferably 180 Pa‧s, and the upper limit is 150 Pa‧s.

The above η2 and the above ratio (η1/η2) can be adjusted by using a crystalline resin as a curable compound or a surface-treated filler for improving hydrophilicity. From the viewpoint of easily controlling the above η2 and the above ratio (η1/η2) within the above range, the curable compound preferably contains a crystalline resin.

As a method of hardening the anisotropic conductive material of the present invention, a method of heating an anisotropic conductive material after irradiating light to an anisotropic conductive material; and heating the anisotropic conductive material, A method in which an anisotropic conductive material illuminates light. Further, when the speed of photohardening and the speed of thermal curing are different, light irradiation and heating can be simultaneously performed. Among them, a method of heating the anisotropic conductive material after irradiating the anisotropic conductive material is preferred. By using photohardening and thermal hardening together, the anisotropic conductive material can be hardened in a short time.

(Manufacturing method of connection structure and connection structure)

The connection structure can be obtained by connecting the connection member members using the anisotropic conductive material of the present invention.

Preferably, the connection structure includes a first connection target member, a second connection target member, and a connection portion electrically connecting the first connection member and the second connection target member, and the connection portion is formed by the anisotropy Formed by a conductive material. The connecting portion is a cured layer obtained by curing the anisotropic conductive material.

Next, a connection structure using an anisotropic conductive material according to an embodiment of the present invention and a method of manufacturing the connection structure will be described in more detail with reference to the drawings.

In Fig. 1, an example of a connection structure using an anisotropic conductive material according to an embodiment of the present invention is schematically shown in a partially cutaway front cross-sectional view.

The connection structure 1 shown in FIG. 1 has a structure in which the second connection target member 4 is connected to the upper surface 2a of the first connection object member 2 via the cured layer 3. The cured layer 3 is a joint. The cured layer 3 is formed by curing an anisotropic conductive material containing a curable compound, a thermosetting agent, a photocuring initiator, and conductive particles 5. The anisotropic conductive material includes a plurality of conductive particles 5. A plurality of electrodes 2b are provided on the upper surface 2a of the first connection object member 2. A plurality of electrodes 4b are provided on the lower surface 4a of the second connection member 4. The electrode 2b and the electrode 4b are electrically connected by one or a plurality of conductive particles 5.

In the connection structure 1, a glass substrate is used as the first connection target member 2, and a semiconductor wafer is used as the second connection target member 4. The first and second connection target members are not particularly limited. Specific examples of the first and second connection target members include electronic components such as a semiconductor wafer, a capacitor, and a diode, and a circuit board such as a printed circuit board, a flexible printed circuit board, and a glass substrate. The connection structure 1 shown in Fig. 1 is obtained, for example, in the following manner.

As shown in Fig. 2(a), the first connection member 2 having the electrode 2b on the upper surface 2a is prepared. Next, an anisotropic conductive material containing a plurality of conductive particles 5 is applied to the upper surface 2a of the first connection member 2, and an anisotropic conductive material layer 3A is formed on the upper surface 2a of the first connection member 2. In this case, it is preferred to dispose one or a plurality of conductive particles 5 on the electrode 2b.

Next, as shown in FIG. 2(b), the anisotropic conductive material layer 3A is cured by irradiating light to the anisotropic conductive material layer 3A. The hardening of the anisotropic conductive material layer 3A is performed to cause the anisotropic conductive material layer 3A to be B-staged. A B-staged anisotropic conductive material layer 3B is formed on the upper surface 2a of the first connection object member 2.

When the anisotropic conductive material layer 3A is hardened and the anisotropic conductive material layer 3A is B-staged, the viscosity of the B-staged anisotropic conductive material layer 3B is preferably (hereinafter, sometimes The anisotropic conductive material layer 3A is B-staged in a manner in which it is abbreviated as η3) in the range of 2,000 to 3,500 Pa‧s. By setting the viscosity η3 within the above range, the flow of the anisotropic conductive material layer can be sufficiently suppressed. Therefore, it is easy to arrange the electroconductive particle 5 between the electrodes 2b and 4b. Further, it is possible to suppress the unintentional conductive material layer from inadvertently flowing to a region closer to the side than the outer peripheral surface of the first connection member 2 or the second connection member 4.

From the viewpoint of further suppressing the flow of the anisotropic conductive material layer and the conductive particles 5, the lower limit of the viscosity η3 is preferably 2250 Pa‧s, and the upper limit is preferably 3250 Pa‧s. A preferred lower limit of the measurement temperature of the viscosity η3 is 20 ° C, and a preferred upper limit is 30 ° C. The measurement temperature of the above viscosity η3 is particularly preferably 25 °C.

It is preferable that the anisotropic conductive material layer 3A is irradiated with light while applying the anisotropic conductive material to the upper surface 2a of the first connection object member 2. Further, it is also preferable that the anisotropic conductive material is applied to the upper surface 2a of the first connection member 2 or the anisotropic conductive material layer 3A is irradiated with light immediately after the application. When the coating and the irradiation of light are performed in the above manner, the flow of the anisotropic conductive material layer can be further suppressed. Therefore, the conduction reliability of the resulting connection structure 1 can be further improved. The time from the application of the anisotropic conductive material to the upper surface 2a of the first connection member 2 to the irradiation of light is preferably in the range of 0 to 3 seconds, more preferably in the range of 0 to 2 seconds.

It is preferable that the anisotropic conductive material layer 3A is irradiated with light while applying the anisotropic conductive material to the upper surface 2a of the first connection object member 2. Further, it is also preferable that the anisotropic conductive material is applied to the upper surface 2a of the first connection member 2 or the anisotropic conductive material layer 3A is irradiated with light immediately after the application. When coating and light irradiation are performed as described above, the flow of the anisotropic conductive material layer can be further suppressed. Therefore, the conduction reliability of the resulting connection structure 1 can be further improved. The time from the application of the anisotropic conductive material to the upper surface 2a of the first connection member 2 to the irradiation of light is preferably in the range of 0 to 3 seconds, more preferably in the range of 0 to 2 seconds.

When the anisotropic conductive material layer 3A is B-staged by irradiation with light, the light irradiation intensity for appropriately curing the anisotropic conductive material layer 3A is, for example, about 0.1 to 100 mW/cm ² .

The light source used when irradiating light is not particularly limited. Examples of the light source include a light source having a sufficient light emission distribution at a wavelength of 420 nm or less. Further, specific examples of the light source include a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a chemical lamp, a black light lamp, a microwave excited mercury lamp, and a metal halide lamp.

Next, as shown in FIG. 2(c), the second connection member 4 is laminated on the upper surface 3a of the B-staged anisotropic conductive material layer 3B. The second connection member 4 is laminated so that the electrode 2b on the upper surface 2a of the first connection member 2 and the electrode 4b on the lower surface 4a of the second connection member 4 face each other.

Further, when the second connection member 4 is laminated, heat is applied to the anisotropic conductive material layer 3B, whereby the anisotropic conductive material layer 3B is further cured to form the cured layer 3. However, heat may be applied to the anisotropic conductive material layer 3B before the second connection object member 4 is laminated. Furthermore, it is preferable to apply heat to the anisotropic conductive material layer 3B after the second connection target member 4 is laminated, and to completely cure it.

In the case where the anisotropic conductive material layer 3B is cured by imparting heat, a preferred lower limit of the heating temperature for sufficiently hardening the anisotropic conductive material layer 3B is 160 ° C, and a preferred upper limit is 250 ° C. The upper limit is 200 °C.

It is preferred to pressurize the anisotropic conductive material layer 3B when it is hardened. By compressing the conductive particles 5 by the electrodes 2b and 4b by pressurization, the contact area between the electrodes 2b and 4b and the conductive particles 5 can be increased. Therefore, the conduction reliability can be improved.

By curing the anisotropic conductive material layer 3B, the first connection object member 2 and the second connection object member 4 are connected via the cured layer 3 . Further, the electrode 2b and the electrode 4b are electrically connected via the conductive particles 5. In this way, the connection structure 1 shown in Fig. 1 can be obtained. In the present embodiment, since photohardening and thermal curing are used in combination, the anisotropic conductive material can be cured in a short time.

When the connection structure 1 is obtained, it is preferred to irradiate the anisotropic conductive material layer 3A with light to form the B-staged anisotropic conductive material layer 3B, and then apply heat to the anisotropic conductive material layer 3B.

When the anisotropic conductive material layer 3A is formed and the anisotropic conductive material layer 3A is B-staged, the composite device shown in Fig. 3(a) is preferably used.

The composite device 11 shown in Fig. 3(a) includes a dispenser 12 and a light irradiation device 13 connected to the dispenser 12. The dispenser 12 includes a syringe 12a for filling an anisotropic conductive material inside, and a grip portion 12b for holding the outer peripheral surface of the syringe 12a. The light irradiation device 13 includes a light irradiation device body 13a and a light irradiation portion 13b. In the composite device 11, the grip portion 12b is connected to the light irradiation device body 13a. Therefore, the distance between the dispenser 12 and the light irradiation device 13 can be reduced, that is, the distance between the discharge portion of the dispenser 12 and the light irradiation portion 13b can be reduced. Further, the dispenser 12 can be easily moved at the same speed as the light irradiation device 13. Further, the syringe 12a and the light irradiation device body 13a may be directly connected.

As shown in Fig. 3 (a), when the coating device and the light are irradiated, the composite device 11 is moved in the direction of the arrow A, and the counter surface 12a is applied to the upper surface 2a of the first connection member 2 from the syringe 12a. A conductive material forms an anisotropic conductive material layer 3A. Moreover, the light-irradiating portion 13b of the light-irradiating device 13 connected to the dispenser 12 is irradiated with light to the anisotropic conductive material layer 3A as indicated by an arrow B.

It is preferable from the viewpoint of further suppressing the flow of the conductive particles 5A formed on the upper surface 2a of the first connection member 2 and the conductive particles 5 contained in the anisotropic conductive material layer 3A. The application and the irradiation of light are performed while moving the dispenser 12 and the light irradiation device 13. Further, from the viewpoint of controlling the time until the irradiation light with high precision, it is preferable that the dispenser 12 and the light irradiation device 13 move at the same speed. However, the platform 31 may be moved in the direction of the arrow A without moving the composite device 11.

As shown in FIG. 4(a), a dispenser 12 and a light irradiation device 21 not connected to the dispenser 12 may be used. Similarly to the light irradiation device 13, the light irradiation device 21 includes the light irradiation device main body 21a and the light irradiation portion 21b. The light irradiation device 21 is configured to be capable of illuminating a region wider than the light irradiation device 13.

When the dispenser 12 and the light irradiation device 21 that is not connected to the dispenser 12 are used, for example, as shown in FIG. 4(a), the light irradiation device 21 is disposed above the first connection member 2. Then, the injector 12 is coated with the anisotropic conduction from the upper surface 2a of the first connection member 2 from the syringe 12a while moving the dispenser 12 between the first connection member 2 and the light irradiation device 21 in the direction of the arrow A. The material forms an anisotropic conductive material layer 3A. Then, as shown in FIG. 4(b), after the application of the anisotropic conductive material is completed, the light irradiation portion 21b of the light irradiation device 21 disposed above the first connection member 2 is anisotropically conductive. The material layer 3A illuminates the light. The irradiation of light is performed, for example, at the same time as the application of the anisotropic conductive material or immediately after coating.

The light irradiation device 21 is preferably disposed above the first connection member 2 at the time of coating. In this case, light can be quickly irradiated after coating. It is preferred that the entire region of the anisotropic conductive material layer 3A is irradiated with light after coating. In this case, the anisotropic conductive material layer 3A can be more uniformly B-staged.

By using the apparatus shown in FIG. 3(a) or FIG. 4(a), it is possible to easily apply the anisotropic conductive material to the upper surface 2a of the first connection member 2 or just after coating. The anisotropic conductive material layer 3A is irradiated with light.

Since the anisotropic conductive material used in the method for producing a connection structure of the present invention contains a curable compound, a thermosetting agent, a photocuring initiator, and conductive particles, it can be sufficiently suppressed from being applied to the first connection member 2 The flow of the anisotropic conductive material on the upper surface 2a or the conductive particles contained in the anisotropic conductive material.

The method for producing an anisotropic conductive material and a connection structure of the present invention can be used, for example, for connection between a flexible printed substrate and a glass substrate (FOG (Film on Glass)), and connection between a semiconductor wafer and a flexible printed substrate (COF ( Chip on Film), or a connection between a semiconductor wafer and a glass substrate (COG (Chip on Glass)). Among them, the production method of the anisotropic conductive material and the connection structure of the present invention is suitable for COG use. The method for producing an anisotropic conductive material and a connection structure of the present invention can be suitably used for connection of a semiconductor wafer to a glass substrate. However, the use of the anisotropic conductive material and the method for producing the bonded structure of the present invention is not limited to the above use.

In the COG application, in many cases, it is difficult to reliably connect the semiconductor wafer and the electrode of the glass substrate with the conductive particles of the anisotropic conductive material. For example, in the case of COG use, the interval between adjacent electrodes of the semiconductor wafer and the adjacent electrodes of the glass substrate may be about 10 to 20 μm, and in many cases, fine wiring is formed. Even if fine wiring is formed, the semiconductor wafer and the electrode of the glass substrate can be connected with high precision by the method of manufacturing the anisotropic conductive material and the connection structure of the present invention, and the conduction reliability can be improved.

Further, in the case of COG use, it is necessary to increase the content of the conductive particles in the anisotropic conductive material. Therefore, at the time of pressure bonding, the number of conduction contacts may increase, and the repulsive force of the conductive particles may increase, and the pressure at the time of pressure bonding needs to be increased. Therefore, the electrode or the conductive particles are broken, and the conduction reliability is apt to become low. However, by using the anisotropic conductive material of the present invention and the method of manufacturing the bonded structure, the conduction reliability can be sufficiently improved.

Hereinafter, the present invention will be specifically described by way of examples and comparative examples. The invention is not limited to the following examples.

(Example 1)

(1) Preparation of a mixture containing an episulfide compound

250 mL of ethanol, 250 mL of pure water, and 20 g of potassium thiocyanate were placed in a 2 L vessel equipped with a stirrer, a cooler, and a thermometer to dissolve the potassium thiocyanate to prepare a first solution. Thereafter, the temperature in the vessel was maintained in the range of 20 to 25 °C. Next, 160 g of resorcinol diglycidyl ether was added dropwise to the first solution at a rate of 5 mL/min while stirring the first solution held in a container of 20 to 25 °C. After the dropwise addition, the mixture was further stirred for 30 minutes to obtain a mixed solution containing an epoxy compound.

Next, a second solution in which 20 g of potassium thiocyanate was dissolved in a solution containing 100 mL of pure water and 100 mL of ethanol was prepared. The obtained second solution was added to the obtained epoxy group-containing mixed solution at a rate of 5 mL/min, followed by stirring for 30 minutes. After stirring, the second solution in which 20 g of potassium thiocyanate was dissolved in a solution containing 100 mL of pure water and 100 mL of ethanol was further prepared, and the second solution was further added to the vessel at a rate of 5 mL/min, and stirred. minute. Thereafter, the temperature in the vessel was cooled to 10 ° C and stirred for 2 hours to carry out a reaction.

Next, 100 mL of saturated brine was added to the vessel, and the mixture was stirred for 10 minutes. After stirring, 300 mL of toluene was further added to the vessel and stirred for 10 minutes. Thereafter, the solution in the vessel was transferred to a separatory funnel and allowed to stand for 2 hours to separate the solution. The solution below the separatory funnel was drained, and the supernatant was taken out. 100 mL of toluene was added to the supernatant, and the mixture was stirred and allowed to stand for 2 hours. Further, 100 mL of toluene was further added, stirred, and allowed to stand for 2 hours.

Next, 50 g of magnesium sulfate was added to the supernatant to which toluene was added, and the mixture was stirred for 5 minutes. After stirring, magnesium sulfate was removed by filter paper, and the solution was separated. The separated solution was dried under reduced pressure at 80 ° C using a vacuum dryer, thereby removing the remaining solvent. Thus, a mixture containing an episulfide compound was obtained.

The ¹ H-NMR measurement of the obtained mixture containing the episulfide compound was carried out using chloroform as a solvent. As a result, a signal indicating a region of 6.5 to 7.5 ppm in which an epoxy group is present is reduced, and a signal appears in a region of 2.0 to 3.0 ppm indicating the presence of an episulfide group. From this, it was confirmed that a part of the epoxy group of resorcinol diglycidyl ether was converted into an episulfide group. In addition, it was confirmed that the mixture containing the episulfide compound contained 70% by weight of resorcinol diglycidyl ether and the episulfide compound 30 having the structure represented by the above formula (1B), based on the integral value of the measurement result of ¹ H-NMR. weight%.

(2) Preparation of anisotropic conductive paste

5 parts by weight of an amine adduct ("PN-23J" manufactured by Ajinomoto Fine Techno Co., Ltd.) as a thermosetting agent, and epoxy acrylate as a photocurable compound, were blended in an amount of 30 parts by weight of the mixture of the obtained sulfonated compound. 5 parts by weight of an ester ("EBECRYL 3702" manufactured by Daicel-Cytec Co., Ltd.), 0.1 part by weight of a fluorenylphosphine oxide-based compound ("DAROCUR TPO" manufactured by Ciba Japan Co., Ltd.) as a photopolymerization initiator, and as a hardening accelerator 1 part by weight of 2-ethyl-4-methylimidazole, 20 parts by weight of cerium oxide having an average particle diameter of 0.25 μm as a filler, and 20 parts by weight of alumina having an average particle diameter of 0.5 μm, and further The conductive particles having an average particle diameter of 3 μm were added so as to have a content of 100% by weight of 10% by weight, and then stirred at 2000 rpm for 5 minutes using a planetary mixer to obtain a formulation.

Further, the conductive particles to be used are conductive particles having a nickel plating layer formed on the surface of the divinylbenzene resin particles and having a metal layer formed on the surface of the nickel plating layer.

The obtained preparation was filtered using a nylon filter paper (pore size: 10 μm), whereby an anisotropic conductive paste having a conductive particle content of 10% by weight was obtained.

(3) Production of connection structure

A transparent glass substrate having an ITO (Indium Tin Oxide) electrode pattern having an L/S of 30 μm/30 μm was formed on the upper surface. Further, a semiconductor wafer having a copper electrode pattern of L/S of 30 μm/30 μm was formed on the lower surface.

The obtained anisotropic conductive paste was applied to the transparent glass substrate so as to have a thickness of 30 μm to form an anisotropic conductive paste layer. Next, the anisotropic conductive paste layer is irradiated with ultraviolet rays using an ultraviolet irradiation lamp, and the anisotropic conductive paste layer is semi-hardened by photopolymerization to be B-staged. Then, on the anisotropic conductive paste layer, the semiconductor wafer is laminated with the electrodes facing each other. Then, while adjusting the temperature of the head so that the temperature of the anisotropic conductive paste layer became 185 ° C, a pressure heating head was placed on the upper surface of the semiconductor wafer, and a pressure of 3 MPa was applied to make a difference at 185 ° C. The directional conductive paste layer is completely cured to obtain a bonded structure.

(Example 2)

In the same manner as in Example 1, the content of the conductive particles was 5 in the same manner as in Example 1 except that the conductive particles were used in an amount of 5% by weight in the amount of 100% by weight of the above-mentioned formulation. % by weight of an anisotropic conductive paste. A bonded structure was obtained in the same manner as in Example 1 except that the obtained anisotropic conductive paste was used.

(Example 3)

In the case of using the conductive particles, the content of the conductive particles was 15 in the same manner as in Example 1 except that the conductive particles were used in an amount of 15% by weight based on 100% by weight of the above-mentioned formulation. % by weight of an anisotropic conductive paste. A bonded structure was obtained in the same manner as in Example 1 except that the obtained anisotropic conductive paste was used.

(Example 4)

In the same manner as in Example 1, the content of the conductive particles was 1 in the same manner as in Example 1 except that the conductive particles were used in an amount of 1% by weight in the amount of 100% by weight of the above-mentioned formulation. % by weight of an anisotropic conductive paste. A bonded structure was obtained in the same manner as in Example 1 except that the obtained anisotropic conductive paste was used.

(Comparative Example 1)

In the same manner as in Example 1, except that the epoxy acrylate as the photocurable compound and the fluorenyl phosphine oxide compound as the photopolymerization initiator were not used in the preparation of the anisotropic conductive paste. A conductive paste. The content of the conductive particles in 100% by weight of the obtained anisotropic conductive paste was 10% by weight. A bonded structure was obtained in the same manner as in Example 1 except that the obtained anisotropic conductive paste was used.

(Comparative Example 2)

In the case of using the conductive particles, the content of the conductive particles was 20 in the same manner as in Example 1 except that the conductive particles were used in an amount of 20% by weight based on 100% by weight of the above-mentioned formulation. % by weight of an anisotropic conductive paste. A bonded structure was obtained in the same manner as in Example 1 except that the obtained anisotropic conductive paste was used.

(Comparative Example 3)

In the same manner as in Example 1, except that the conductive particles were used in the case where the content of the above-mentioned formulation was 0.1% by weight, the content of the conductive particles was 0.1. % by weight of an anisotropic conductive paste. A bonded structure was obtained in the same manner as in Example 1 except that the obtained anisotropic conductive paste was used.

(Evaluation of Examples 1 to 4 and Comparative Examples 1 to 3)

(1) Viscosity

The viscosity of the obtained anisotropic conductive paste (viscosity of the anisotropic conductive paste before coating) was measured at 25 ° C and 2.5 rpm using an E-type viscometer (manufactured by Toki Sangyo Co., Ltd.).

(2) Whether there is a leak

Using the obtained connection structure, a test machine was used to measure whether or not leakage occurred in 20 adjacent electrodes.

(3) Whether there is a gap

In the obtained bonded structure, whether or not voids were generated in the cured layer formed of the anisotropic conductive paste layer was visually observed from the lower surface side of the transparent glass substrate.

The results are shown in Table 1 below.

As shown in the above Table 1, the anisotropic conductive pastes of Examples 1 to 4 were free from leakage and voids were not observed.

In the anisotropic conductive paste of Comparative Example 1, since the ultraviolet ray is not semi-hardened by photopolymerization upon irradiation with ultraviolet rays, the anisotropic conductive paste flows to a larger extent than the semiconductor wafer at the time of pressurization and heating. The side is more lateral. Therefore, the filling of the anisotropic conductive paste between the glass substrate and the semiconductor wafer is insufficient, and voids are observed.

In Comparative Example 2, since the content of the conductive particles was too large, the adjacent electrodes which should not be connected were connected via a plurality of conductive particles, and leakage occurred.

For the anisotropic conductive paste of Comparative Example 3, no leakage was observed and no void was observed. However, since the content of the conductive particles is too small, a portion where the conductive particles are not disposed between the electrodes is observed.

(Example 5)

The anisotropic conductive material obtained in Example 1 was prepared.

A transparent glass substrate having an ITO electrode pattern of L/S of 30 μm/30 μm was formed on the upper surface. Further, a semiconductor wafer having a copper electrode pattern of L/S of 30 μm/30 μm was formed on the lower surface.

Further, a composite device including a dispenser and an ultraviolet irradiation lamp as a light irradiation device connected to the dispenser is shown in Fig. 3(a).

While the composite device was moved, the obtained anisotropic conductive paste was applied to the upper surface of the transparent glass substrate by a syringe from the dispenser to have a thickness of 30 μm to form an anisotropic conductive paste layer. Further, while the composite device was moved, the anisotropic conductive paste was applied, and the ultraviolet ray irradiation lamp was used to irradiate the anisotropic conductive paste layer with ultraviolet rays of 420 nm so that the light irradiation intensity was 50 mW/cm ² . Photopolymerization causes the anisotropic conductive paste layer to be B-staged. The time T from the time when the coated anisotropic conductive paste was applied to the transparent glass substrate to the time when the light was applied to the anisotropic conductive paste layer was 0.5 second.

Next, the semiconductor wafer is laminated on the surface of the B-staged anisotropic conductive paste layer so that the electrodes face each other. Thereafter, while adjusting the temperature of the head so that the temperature of the anisotropic conductive paste layer became 185 ° C, a pressure heating head was placed on the upper surface of the semiconductor wafer, and a pressure of 3 MPa was applied to make the pressure at 185 ° C. The B-staged anisotropic conductive paste layer is completely cured to obtain a bonded structure.

(Example 6)

An anisotropy was obtained in the same manner as in Example 1 except that the epoxy acrylate was changed to acrylamide (EBECRYL 8804) manufactured by Daicel-Cytec Co., Ltd. in the preparation of the anisotropic conductive paste. Conductive paste.

A bonded structure was obtained in the same manner as in Example 5 except that the obtained anisotropic conductive paste was used.

(Example 7)

The anisotropic conductive material obtained in Example 1 was prepared.

Instead of the composite device shown in Fig. 3(a), the dispenser shown in Fig. 4(a) and the ultraviolet irradiation lamp as the light irradiation device, which is not connected to the dispenser, are coated on the anisotropic conductive paste. A connection structure was obtained in the same manner as in Example 5 except that the light was irradiated immediately after the completion of the cloth. The time T from the application to the irradiation of light was 2 seconds.

(Comparative Example 4)

The anisotropic conductive material obtained in Comparative Example 1 was prepared.

A transparent glass substrate having an ITO electrode pattern of L/S of 30 μm/30 μm was formed on the upper surface. Further, a semiconductor wafer having a copper electrode pattern of L/S of 30 μm/30 μm was formed on the lower surface.

The syringe from the dispenser was applied to the upper surface of the transparent glass substrate to coat the obtained anisotropic conductive paste to a thickness of 30 μm to form an anisotropic conductive paste layer. No light is applied at the time of coating and after coating.

Next, the semiconductor wafer is laminated on the upper surface of the anisotropic conductive paste layer with the electrodes facing each other. Then, while adjusting the temperature of the head so that the temperature of the anisotropic conductive paste layer became 185 ° C, a pressure heating head was placed on the upper surface of the semiconductor wafer, and a pressure of 3 MPa was applied to make a difference at 185 ° C. The directional conductive paste layer is completely cured to obtain a bonded structure.

(Comparative Example 5)

When the anisotropic conductive paste is produced, the epoxy acrylate is changed to a naphthalene type epoxy resin (crystalline resin, "HP-4032" manufactured by DIC Corporation), and the sulfhydryl group as a photopolymerization initiator is not used. An anisotropic conductive paste was obtained in the same manner as in Example 1 except for the phosphine oxide-based compound.

A transparent glass substrate having an ITO electrode pattern of L/S of 30 μm/30 μm was formed on the upper surface. Further, a semiconductor wafer having a copper electrode pattern of L/S of 30 μm/30 μm was formed on the lower surface.

The syringe from the dispenser was applied to the upper surface of the transparent glass substrate to coat the obtained anisotropic conductive paste to a thickness of 30 μm to form an anisotropic conductive paste layer. The light was not irradiated at the time of coating and after coating, and thermal polymerization was not performed, and the anisotropic conductive material layer was not B-staged.

Next, the semiconductor wafer is laminated on the upper surface of the anisotropic conductive paste layer which is not B-staged so that the electrodes face each other. Then, while adjusting the temperature of the head so that the temperature of the anisotropic conductive paste layer became 185 ° C, a pressure heating head was placed on the upper surface of the semiconductor wafer, and a pressure of 3 MPa was applied to make a difference at 185 ° C. The directional conductive paste layer is completely cured to obtain a bonded structure.

(Evaluation of Examples 5 to 7 and Comparative Examples 4 to 5)

In the same manner as in Examples 1 to 4 and Comparative Examples 1 to 3, the evaluation of the above (1) viscosity, the presence or absence of the above (2) leakage, and the presence or absence of the above (3) voids were evaluated. Further, the viscosity of the B-staged anisotropic conductive paste layer was evaluated in the following (4).

(4) Viscosity of the B-staged anisotropic conductive paste layer

Using a rheometer (manufactured by Anton Paar Co., Ltd.), the anisotropic conductive paste layer was B-staged by photopolymerization at 25 ° C and 2.5 rpm, and the B-ordered anisotropy was applied. The viscosity of the B-staged anisotropic conductive paste layer before the surface area layer semiconductor wafer above the conductive paste layer was measured.

The results are shown in Table 2 below.

(Example 8)

In 16 parts by weight of resorcinol-type epoxy resin (crystalline resin, "EX-201" manufactured by Nagase ChemteX Co., Ltd.), a naphthalene type epoxy resin (crystalline resin, "HP-4032" manufactured by DIC Corporation) was prepared. 14 parts by weight of an amine adduct ("PN-23J" manufactured by Ajinomoto Fine-Techno Co., Ltd.) as a thermosetting agent, and epoxy acrylate as a photocurable resin (manufactured by Daicel-Cytec Co., Ltd.) EBECRYL 3702") 0.1 parts by weight of a fluorenyl phosphine oxide-based compound ("DAROCUR TPO" manufactured by Ciba Japan Co., Ltd.) as a photo-curing initiator, 2-ethyl-4-methylimidazole as a hardening accelerator 1 part by weight, and 30 parts by weight of cerium oxide having an average particle diameter of 0.25 μm as a filler, and further, conductive particles having an average particle diameter of 3 μm are added so as to have a content of 10% by weight in the preparation, and then used. The planetary mixer was stirred at 2000 rpm for 5 minutes, thereby obtaining a formulation.

Further, the conductive particles to be used are formed by forming a nickel plating layer on the surface of the divinylbenzene resin particles, and forming a metal layer-containing conductive particles on the surface of the nickel plating layer.

The resulting formulation was filtered using a nylon filter paper (pore size: 10 μm), whereby an anisotropic conductive paste was obtained. A bonded structure was obtained in the same manner as in Example 1 except that the obtained anisotropic conductive paste was used.

(Example 9)

The amount of the resorcinol-type epoxy resin is changed from 16 parts by weight to 25 parts by weight, and 14 parts by weight of the naphthalene type epoxy resin is changed to a bisphenol A type epoxy resin ("Epikote 1001" manufactured by JER Corporation) An anisotropic conductive paste was obtained in the same manner as in Example 8 except for 5 parts by weight. A bonded structure was obtained in the same manner as in Example 1 except that the obtained anisotropic conductive paste was used.

(Comparative Example 6)

30 parts by weight of polyglycidylamine ("YH-434" manufactured by Tosho Kasei Co., Ltd.), 30 parts by weight of bisphenol A type epoxy resin ("JER1001" manufactured by JER Corporation), and dicyandiamide as a heat hardener Amine ("DICY-7" manufactured by JER Corporation) 10 parts by weight, 1 part by weight of 2-ethyl-4-methylimidazole as a curing accelerator, and cerium oxide as a filler (Aerosil manufactured by Aerosil Industries, Japan) In the same manner as in Example 8, the conductive particles were added in an amount of 10% by weight in the formulation, and the mixture was stirred at 2000 rpm for 5 minutes using a planetary mixer to obtain a formulation.

The resulting formulation was filtered using a nylon filter paper (pore size: 10 μm), whereby an anisotropic conductive paste was obtained. A bonded structure was obtained in the same manner as in Example 1 except that the obtained anisotropic conductive paste was used.

(Evaluation of Examples 8 to 9 and Comparative Example 6)

In the same manner as in Examples 1 to 4 and Comparative Examples 1 to 3, the presence or absence of the above (2) leakage and the presence or absence of the above (3) voids were evaluated. Further, the following (1A) viscosity, (5) coating width unevenness, and (6) thickness of the cured layer were evaluated.

(1A) Viscosity

The viscosity of the obtained anisotropic conductive paste at 25 ° C and 2.5 rpm and the viscosity η 2 at 25 ° C and 5 rpm were measured using an E-type viscometer (manufactured by Toki Sangyo Co., Ltd.).

(5) Uneven coating width

The obtained anisotropic conductive paste was filled in a syringe having a nozzle diameter of 1.1 mm, using a dispenser at a pressure of 300 Pa, a coating thickness of 30 μm, a moving speed of 10 mm/s, a coating linear distance of 20 mm, and The anisotropic conductive paste was applied onto a glass substrate under the conditions of a coating width of 1 mm.

The coating width of each point from the start point of the application of the anisotropic conductive paste from the point of application of the distance of 2 mm, the distance of 5 mm, and the distance of 10 mm was measured with a microscope with a distance measuring function.

(6) Height of the hardened layer (thickness)

The anisotropic conductive paste was applied onto a glass substrate in the same manner as the evaluation of the above (5). Immediately after the application, ultraviolet rays were irradiated, and photohardening of the anisotropic conductive paste was started. Further, 10 seconds after the irradiation of the ultraviolet rays, the glass substrate coated with the anisotropic conductive paste was placed in an oven at 150 ° C for 5 minutes to thermally harden the anisotropic conductive paste. The height of the cured layer formed by the hardening of the anisotropic conductive paste was measured by a micrometer.

The results are shown in Table 3 below.

The anisotropic conductive pastes of Examples 8 to 9 were stably coated, and the coating width was almost fixed. Further, in the anisotropic conductive paste of Example 8, the flow of the anisotropic conductive paste was suppressed at the time of coating, and thus the thickness of the obtained cured layer was 30 μm.

In the anisotropic conductive paste of Comparative Example 6, although the coating pressure was fixed, the coating amount was changed, and the coating width was uneven.

1. . . Connection structure

2. . . First connection object member

2a. . . Upper surface

2b. . . electrode

3. . . Hardened layer (connection)

3A. . . Anisotropic conductive material layer

3B. . . B-staged anisotropic conductive material layer

3a. . . Upper surface

4. . . Second connection object member

4a. . . lower surface

4b. . . electrode

5. . . Conductive particles

11. . . Composite device

12. . . Dispenser

12a. . . syringe

12b. . . Grip

13. . . Light irradiation device

13a. . . Light illumination device body

13b. . . Light irradiation department

twenty one. . . Light irradiation device

21a. . . Light illumination device body

21b. . . Light irradiation department

31. . . platform

Fig. 1 is a partially cutaway front cross-sectional view schematically showing a connection structure using an anisotropic conductive material according to an embodiment of the present invention.

2(a) to 2(c) are partially cutaway front cross-sectional views for explaining respective steps of a method of manufacturing a bonded structure using an anisotropic conductive material according to an embodiment of the present invention.

3(a) and 3(b) are diagrams showing a method of manufacturing a connection structure using an anisotropic conductive material according to an embodiment of the present invention, using a composite device including a dispenser and a light irradiation device to form a A schematic front view illustrating a method of a B-staged anisotropic conductive material layer.

4(a) and 4(b) are schematic front views for explaining a modification of the method of forming the B-staged anisotropic conductive material layer.

2. . . First connection object member

2a. . . Upper surface

2b. . . electrode

3A. . . Anisotropic conductive material layer

3B. . . B-staged anisotropic conductive material layer

3a. . . Upper surface

4. . . Second connection object member

4a. . . lower surface

4b. . . electrode

5. . . Conductive particles

Claims (10)

An anisotropic conductive material containing a curable compound, a thermosetting agent, a photocuring initiator, and conductive particles, wherein the content of the conductive particles is in the range of 1 to 19% by weight. The anisotropic conductive material of claim 1, wherein the hardenable compound comprises an episulfide compound. The anisotropic conductive material of claim 1, wherein the curable compound comprises a curable compound having at least one of an epoxy group and a cyclothioethyl group and a (meth) acrylonitrile group. The anisotropic conductive material of claim 2, wherein the curable compound comprises a curable compound having at least one of an epoxy group and an episulfide group and a (meth) acrylonitrile group. The anisotropic conductive material according to any one of claims 1 to 4, wherein the viscosity at 25 ° C and 2.5 rpm is in the range of 20 to 200 Pa ‧ s. The anisotropic conductive material according to any one of claims 1 to 4, wherein the hardening is performed by light irradiation, and the viscosity after B-stage is in the range of 2000 to 3500 Pa‧s. The anisotropic conductive material according to any one of claims 1 to 4, wherein the viscosity at 25 ° C and 2.5 rpm is η1, and the viscosity at 25 ° C and 5 rpm is η 2 , the above η 2 is 20 Pa ‧ s The above ratio is 200 Pa‧s or less, and the ratio (η1/η2) of the above η1 to the above η2 is 0.9 or more and 1.1 or less. The anisotropic conductive material of claim 7, wherein the hardenable compound comprises a crystalline compound. A connection structure including a first connection target member, a second connection target member, and a connection portion electrically connecting the first and second connection target members, wherein the connection portion is made by requesting items 1 to 4 The anisotropic conductive material of any of them is formed by hardening. A manufacturing method of a connection structure, comprising the steps of: coating an anisotropic conductive material on a surface of a first connection object member to form an anisotropic conductive material layer; and irradiating the anisotropic conductive material layer with light And performing hardening of the anisotropic conductive material layer to B-stage the anisotropic conductive material layer in a manner that the viscosity is in the range of 2000 to 3500 Pa‧s; and the B-staged anisotropic conductive The surface of the material layer is further laminated with the second connection member; and the anisotropic conductive material contains a curable compound, a thermosetting agent, a photocuring initiator, and conductive particles, and the content of the conductive particles is An anisotropic conductive material in the range of 1 to 19% by weight.