KR20200045015A - Circuit connection material, circuit connection structure, adhesive film, and wound body - Google Patents

Abstract

The present invention is a circuit connecting material for electrically connecting two circuit members facing each other, which contains a thermoplastic resin, a radically polymerizable compound, a radical polymerization initiator, and inorganic fine particles, and the content of a radically polymerizable compound is a circuit connecting material. The total content is 40% by mass or more, and the content of the compound having a molecular weight of 1000 or less in the radically polymerizable compound is 15% by mass or less based on the total amount of the circuit connection material, and the content of inorganic fine particles is 5 to 30 based on the total amount of the circuit connection material. It is a circuit connection material which is mass% and contains the compound represented by the following general formula (1).
<Formula 1>

Description

Circuit connecting material, circuit connecting structure, adhesive film and winding body {CIRCUIT CONNECTION MATERIAL, CIRCUIT CONNECTION STRUCTURE, ADHESIVE FILM, AND WOUND BODY}

The present invention relates to a circuit connecting material for electrically connecting two circuit members facing each other, and a circuit connecting structure using the same, an adhesive film and a winding body.

In semiconductor elements and liquid crystal display elements, various circuit connection materials have been conventionally used for the purpose of joining various members in the elements. The characteristics required for the circuit connection material extend over many aspects, such as adhesiveness, heat resistance, and reliability in high temperature and high humidity conditions.

Moreover, as an adherend adhered with a circuit connection material, for example, printed wiring boards, polyimides, organic substrates such as polyethylene terephthalate and polycarbonate, metal substrates such as copper and aluminum, and ITO, IZO, SiN, and And inorganic substrates such as SiO ₂ , and substrates having various surface states are used. For this reason, the circuit connection material needs a molecular design tailored to each adherend (for example, Patent Documents 1 to 2).

Conventionally, as a circuit connection material for a semiconductor element or a liquid crystal display element, a thermosetting resin composition using an epoxy resin exhibiting high adhesion and high reliability has been used (for example, see Patent Document 1). As a constituent component of such a thermosetting resin composition, a curing agent such as an epoxy resin, a phenol resin having reactivity with an epoxy resin, and a thermal latent catalyst that accelerates the reaction between the epoxy resin and the curing agent are generally used.

In the actual process, the above-described circuit connection material was cured at a temperature of 170 to 250 ° C for 1 to 3 hours to obtain desired adhesion. However, with the recent high integration of semiconductor elements and high precision of liquid crystal elements, the pitch between elements and wirings is narrowed, and there is a fear that adverse effects may be exerted on the peripheral members by heating during curing.

In addition, in order to lower the cost, there is a need to improve the throughput, and a lower temperature and a shorter time curing, in other words, adhesion at a lower temperature and faster curing is required. In order to achieve this low-temperature rapid curing, it is necessary to use a thermal latent catalyst having a low activation energy, and it is very difficult to combine storage stability at room temperature.

In recent years, radical-curable adhesives, in which acrylate derivatives and / or methacrylate derivatives (hereinafter referred to as (meth) acrylate derivatives) and a radical polymerization initiator peroxide are used in combination, have attracted attention. In the radical-curable adhesive, since radicals, which are reactive active species, are highly reactive, curing in a short time is possible (for example, see Patent Document 2).

Japanese Patent Publication No. Hei1-113480 International Publication 98/44067 pamphlet

However, the radical curable adhesive is a circuit member when the connection structure is left under a high temperature and high humidity environment such as 85 ° C 85% RH, because the curing shrinkage of the (meth) acrylate is larger than that of the epoxy resin. In many cases, peeling bubbles are generated at the interface between the and circuit connection material. In order to solve this, when the blending amount of (meth) acrylate is reduced, the peeling at the interface between the circuit member and the circuit connecting material can be suppressed, but the adhesive strength becomes low, or the electrical connection between the counter electrodes cannot be maintained. Is done.

The present invention has been made in view of the problems of the prior art, and is capable of sufficiently suppressing the generation of peeling bubbles at the interface with the circuit member even when the circuit member is left under a high temperature and high humidity environment after being connected while being radically polymerized. An adhesive film comprising a circuit connection material that is capable of maintaining sufficient connection reliability, a circuit connection structure produced using the circuit connection material, and a connection material layer containing the circuit connection material, and a roll of the adhesive film The purpose is to provide a sieve.

The present invention is a circuit connecting material for electrically connecting two circuit members facing each other, containing a thermoplastic resin, a radical polymerizable compound, a radical polymerization initiator, and inorganic fine particles, and the content of the radical polymerizable compound is the circuit connection 40 mass% or more based on the total amount of the material, the content of the compound having a molecular weight of 1000 or less in the radically polymerizable compound is 15 mass% or less based on the total amount of the circuit connecting material, and the content of the inorganic fine particles is the A circuit connecting material is provided, which is 5 to 30% by mass based on the total amount and contains at least a compound represented by the following formula (1).

[Wherein, R ¹ , R ² and R ³ each independently represent a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, an alkoxycarbonyl group having 1 to 5 carbon atoms, or an aryl group, and R ¹ and R At least one of ² and R ³ is an alkoxy group having 1 to 5 carbon atoms, and R ⁴ is (meth) acryloyl group, vinyl group, isocyanate group, imidazole group, mercapto group, amino group, methylamino group, dimethylamino group, benzylamino group , Represents a phenylamino group, cyclohexylamino group, morpholino group, piperazino group, ureido group or glycidyl group, n represents an integer of 1 to 10]

Since the circuit connection material of the present invention is a radical curing type, it is possible to bond circuit members to each other at low temperature and in a short time. Further, according to the circuit connection material of the present invention, even when the circuit member is left in a high-temperature and high-humidity environment after connection, generation of peeling bubbles at the interface with the circuit member is sufficiently suppressed, and sufficient connection reliability is maintained.

In the circuit connection material of the present invention, the thermoplastic resin may contain at least one resin having a glass transition temperature of 25 ° C or higher.

In the circuit connection material of the present invention, the average particle diameter of the inorganic fine particles may be less than 1 µm.

In the circuit connecting material of the present invention, conductive particles may be dispersed. By dispersing the conductive particles, it is possible to impart conductivity or anisotropy to the circuit connection material, and such a circuit connection material can be more suitably used for applications such as connecting circuit members having circuit electrodes. Further, by connecting with such a circuit connection material, the connection resistance between the connected circuit electrodes can be sufficiently reduced.

That is, the present invention may be an anisotropic conductive adhesive containing the circuit connecting material and conductive particles dispersed in the circuit connecting material. In addition, in this specification, "a total amount of circuit connection material" does not contain electroconductive particle.

The circuit connection material of the present invention can be formed into a film. Such a circuit connection material is excellent in handling.

In the present invention, at least one of the two circuit members may be a glass substrate. In addition, at least one of the two circuit members may be a flexible substrate. The circuit connecting material of the present invention can be suitably used for connecting such circuit members.

The present invention also includes a pair of circuit members disposed opposite to each other, and a cured product of the circuit connection material, and the circuit electrodes of each circuit member are electrically connected between the pair of circuit members. Provided is a circuit connection structure provided with a connection member that connects the circuit members as much as possible.

Since the circuit members of the present invention are bonded to each other by connecting members comprising a cured product of the circuit connecting material, peeling at the interface between the circuit member and the connecting member even when left under high temperature and high humidity conditions The generation of bubbles is sufficiently suppressed, and sufficient connection reliability is maintained.

The present invention also provides an adhesive film comprising a film substrate and a film-like adhesive comprising the circuit connecting material provided on one side of the film substrate. Since such an adhesive film is provided with the film adhesive containing the said circuit connection material, it can be used suitably for connection between circuit members. Moreover, the adhesive film of this invention can be wound up and stored in reel shape.

When a conventional circuit connection material is coated on one side of a film base material and wound into a reel, a film-like adhesive may be transferred onto the other side of the film base material, making it impossible to use effectively. On the other hand, in the adhesive film of this invention, since a film adhesive contains the said circuit connection material, transfer of the film adhesive on the other side of a film base material is fully suppressed even when it is wound in reel shape.

The present invention also provides a wound body formed by winding the adhesive film in a reel. The winding body of the present invention can be suitably used for connection between circuit members. Further, in the rolled body of the present invention, the transfer of the film-like adhesive onto the other side of the film base is sufficiently suppressed.

In addition, the present invention can also be said to be a use of a composition containing a thermoplastic resin, a radically polymerizable compound, a radical polymerization initiator, and inorganic fine particles as a circuit connecting material for electrically connecting two circuit members facing each other. Here, the content of the radically polymerizable compound is 40% by mass or more based on the total amount of the composition, and the content of the compound having a molecular weight of 1000 or less in the radically polymerizable compound is 15% by mass or less based on the total amount of the composition, The content of the inorganic fine particles is 5 to 30% by mass based on the total amount of the composition, and the composition contains at least a compound represented by the formula (1).

Further, the present invention can also be said to be a use for the production of a circuit connecting material for electrically connecting two circuit members facing each other of a composition containing a thermoplastic resin, a radical polymerizable compound, a radical polymerization initiator, and inorganic fine particles. . Here, the content of the radically polymerizable compound is 40% by mass or more based on the total amount of the composition, and the content of the compound having a molecular weight of 1000 or less in the radically polymerizable compound is 15% by mass or less based on the total amount of the composition, The content of the inorganic fine particles is 5 to 30% by mass based on the total amount of the composition, and the composition contains at least a compound represented by the formula (1).

According to this use, even if the circuit member is a radical polymerization type and the circuit member is left in a high temperature and high humidity environment after being connected, a circuit capable of sufficiently suppressing the occurrence of peeling bubbles at the interface with the circuit member and maintaining sufficient connection reliability Connection material can be obtained.

According to the present invention, a circuit capable of sufficiently suppressing the occurrence of peeling bubbles at the interface with the circuit member and maintaining sufficient connection reliability even when the circuit member is left in a high-temperature and high-humidity environment after connection, according to the present invention. An adhesive film comprising a connecting material, a circuit connecting structure produced using the circuit connecting material, a connecting material layer containing the circuit connecting material, and a wound body of the adhesive film are provided.

1 is a schematic cross-sectional view showing an embodiment of a circuit connecting material of the present invention.
2 is a schematic cross-sectional view showing an embodiment of the connection structure of the present invention.
3 (a) to 3 (c) are process diagrams showing a series of processes for connecting circuit members.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings in some cases. In addition, the same code | symbol is attached | subjected to the same or considerably part in a figure, and the overlapping description is abbreviate | omitted.

In addition, in this specification, (meth) acrylic acid means acrylic acid or methacrylic acid corresponding thereto, (meth) acrylate means acrylate or methacrylate corresponding thereto, and (meth) acryloyl group The term "acryloyl group" or "methacryloyl group" means.

The circuit connection material of the present embodiment can be suitably used to electrically connect two circuit members facing each other, a thermoplastic resin (hereinafter referred to as "(a) component" in some cases), and radical polymerizability. Compound (hereinafter, sometimes referred to as "component (b)"), radical polymerization initiator (hereinafter, referred to as "(c) component" in some cases), and inorganic fine particles (hereinafter, referred to as "(d)" Ingredients).

In the present embodiment, the content of the component (b) is 40% by mass or more based on the total amount of the circuit connection material, and the content of the compound having a molecular weight of 1000 or less in the component (b) is 15% by mass based on the total amount of the circuit connection material. % Or less, and the content of the component (d) is 5 to 30 mass%.

In addition, the circuit connection material of this embodiment contains the compound represented by the following general formula (1) (hereinafter, sometimes referred to as a "silane coupling agent").

<Formula 1>

In Formula 1, R ¹ , R ² and R ³ each independently represent a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, an alkoxycarbonyl group having 1 to 5 carbon atoms, or an aryl group, and R ¹ and R At least one of ² and R ³ is an alkoxy group having 1 to 5 carbon atoms, and R ⁴ is (meth) acryloyl group, vinyl group, isocyanate group, imidazole group, mercapto group, amino group, methylamino group, dimethylamino group, benzylamino group , Phenylamino group, cyclohexylamino group, morpholino group, piperazino group, ureido group or glycidyl group, n represents an integer of 1 to 10.

The silane coupling agent may be blended in the circuit connecting material as part of the radical polymerizable compound of the component (b), or may be blended in the circuit connecting material as components other than the components (a) to (d). For example, when R ⁴ of Formula 1 is a (meth) acryloyl group or a vinyl group, a silane coupling agent is included in the component (b).

Since the circuit connecting member of this embodiment is a radical curing type, it is possible to bond the circuit members to each other at a low temperature and for a short time. Further, according to the circuit connection material of the present embodiment, even when the circuit member is left in a high temperature and high humidity environment after connection, generation of peeling bubbles at the interface with the circuit member is sufficiently suppressed, and sufficient connection reliability is maintained.

As the component (a), a known thermoplastic resin can be used without particular limitation, and a plurality of known thermoplastic resins can be mixed and used.

It is preferable that (a) component contains at least 1 sort (s) or more of resin whose glass transition temperature is 25 degreeC or more from a viewpoint that film formability improves further. Examples of the resin include polyimide resin, polyamide resin, phenoxy resin, poly (meth) acrylate resin, polyester resin, polyurethane resin, and polyvinyl butyral resin. Moreover, (a) component may contain the resin whose glass transition temperature is less than 25 degreeC. In addition, the glass transition temperature of a thermoplastic resin can generally be calculated | required by DSC method or DVE method, and the glass transition temperature in this specification shows the value calculated | required using DSC method.

In the thermoplastic resin of the component (a), a siloxane bond or a fluorine substituent (for example, a fluorine atom, an alkyl fluoride group, or an aryl fluoride group) may be included.

(a) When two or more types of thermoplastic resins are mixed and used as a component, it is preferable that the thermoplastic resins to be mixed are completely compatible, or micro phase separation occurs to become a cloudy state.

It is preferable that the circuit connection material contains at least one resin having a glass transition temperature of 25 ° C or higher as the component (a), and the weight average molecular weight of the resin is preferably 5.0 × 10 ³ to 2.0 × 10 ⁵ , It is more preferable that it is 1.0 × 10 ⁴ to 1.5 × 10 ⁵ .

(a) Among the components, resins having a glass transition temperature of 25 ° C. or higher tend to have poor adhesion to circuit connection materials or insufficient film formability when the weight average molecular weight is less than 5.0 × 10 ³ , and the weight is When the average molecular weight exceeds 2.0 × 10 ⁵ , compatibility with other components of the circuit connecting material is poor, and the fluidity of the circuit connecting material may be lowered. On the other hand, according to the resin whose weight average molecular weight is the said range, the fall of the adhesive force of a circuit connection material and the fall of fluidity can fully be suppressed and connection reliability can be improved further.

In addition, in this specification, the weight average molecular weight shows the weight average molecular weight of polystyrene conversion measured by GPC method.

The circuit connection material may contain a well-known rubber component as (a) component. By adding a rubber component, stress relaxation and improvement of adhesiveness can be expected. Specific examples of the rubber component include acrylic rubber, polyisoprene, polybutadiene, carboxyl group-terminated polybutadiene, hydroxyl group-terminated polybutadiene, 1,2-polybutadiene, carboxyl group-terminated 1,2-polybutadiene, hydroxyl group 1,2-polybutadiene, Styrene-butadiene rubber, hydroxyl group Styrene-butadiene rubber, carboxyl group, hydroxyl group, carbocylation nitrile rubber, hydroxyl group poly (oxypropylene), alkoxysilyl group terminal poly (oxypropylene), poly (oxy tetramethylene) glycol, polyolefin glycol And poly-ε-caprolactone.

The weight average molecular weight of the rubber component is preferably 2.0 × 10 ⁵ to 1.0 × 10 ⁶ . When the weight average molecular weight of the rubber component is less than 2.0 × 10 ^{5, a} sufficient stress relaxation effect may not be obtained, and if it exceeds 1.0 × 10 ⁶ , the fluidity of the circuit connection material may decrease. That is, according to the rubber component whose weight average molecular weight is in the above range, an excellent stress relaxation effect can be obtained while sufficiently suppressing the decrease in fluidity of the circuit connecting material.

As the rubber component, from the viewpoint of improving adhesion, a rubber component having a cyano group or a carboxyl group, which is a high polar group, on the side chain or terminal is preferable. In addition, a rubber component can be used individually by 1 type or in mixture of 2 or more types.

The content of the thermoplastic resin having a glass transition temperature of 25 ° C or higher in the component (a) is preferably 10 to 50% by mass, more preferably 20 to 40% by mass, based on the total amount of the circuit connection material.

When the content of the thermoplastic resin having a glass transition temperature of 25 ° C or higher in the component (a) is less than 10% by mass, the film formability may be poor, and when it exceeds 50% by mass, the fluidity of the circuit connection material may decrease. On the other hand, if it is the said range, the film formability and connection reliability which were excellent still more can be obtained, fully suppressing the fall of the adhesive force of a circuit connection material and the fall of fluidity.

As the component (b), a known radically polymerizable compound can be used. Moreover, (b) component can be used individually by 1 type or in mixture of 2 or more types.

In the present embodiment, the content of the component (b) is 40% by mass or more, preferably 40 to 70% by mass, and more preferably 45 to 65% by mass, based on the total amount of the circuit connection material.

In the present embodiment, as the component (b), a compound having a molecular weight of more than 1000 (hereinafter referred to as "(b-1) component" in some cases) is mainly used, and a compound having a molecular weight of 1000 or less (hereinafter, In some cases, the content of "(b-2) component") is 15% by mass or less based on the total amount of the circuit connection material. When the content of the component (b-1) is 15% by mass or less, the effects of the present invention described above can be remarkably obtained.

(b-2) It is preferable that content of a component is 15 mass% or less, and it is more preferable that it is 12.5 mass% or less. Moreover, content of (b-2) component may be 2.5 mass% or more, and may be 5 mass% or more.

The content of the component (b-1) is 25% by mass or more, preferably 30% by mass or more, and more preferably 35% by mass or more, based on the total amount of the circuit connection material. Moreover, content of (b-1) component may be 55 mass% or less, and may be 50 mass% or less.

(b-1) The molecular weight of the component is preferably 20000 or less, and more preferably 15000 or less. In addition, when the component (b-1) has a molecular weight distribution, the weight average molecular weight of the component (b-1) can be regarded as the molecular weight of (b-1).

In the present embodiment, the ratio (mass ratio) C ₂ / C ₁ of the content C ₂ of the component (b-2) to the content C ₁ of the component (b-1) is preferably 0 to 0.6, and more preferably Preferably it is 0.05 to 0.4, More preferably, it is 0.075 to 0.35.

Examples of the component (b-1) include oligomers such as epoxy (meth) acrylate oligomer, urethane (meth) acrylate oligomer, polyether (meth) acrylate oligomer, and polyester (meth) acrylate oligomer; Trimethylolpropane tri (meth) acrylate, polyethylene glycol di (meth) acrylate, polyalkylene glycol di (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylic Rate, neopentyl glycol di (meth) acrylate, dipentaerythritol hexa (meth) acrylate, isocyanuric acid modified bifunctional (meth) acrylate, isocyanuric acid modified trifunctional (meth) acrylate, bisphenol Epoxy (meth) acrylate in which (meth) acrylic acid is added to the glycidyl group of fluorenediglycidyl ether, and compound in which ethylene glycol and / or propylene glycol is added to the glycidyl group of bisphenol fluorenediglycidyl ether Polyfunctional (meth) acrylates, such as the compound which introduce | transduced the (meth) acryloyloxy group, are mentioned. These compounds can be used individually by 1 type or in mixture of 2 or more types.

Moreover, as a component (b-2), pentaerythritol (meth) acrylate, 2-cyanoethyl (meth) acrylate, cyclohexyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclo Pentenyloxyethyl (meth) acrylate, 2- (2-ethoxyethoxy) ethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n- Hexyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, isobornyl (meth) acrylate, isodecyl (meth) acrylate, isooctyl (meth) acrylic Rate, n-lauryl (meth) acrylate, 2-methoxyethyl (meth) acrylate, 2-phenoxyethyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, 2- (meth) acrylic Loyloxyethyl phosphate, N, N-dimethylaminoethyl (meth) acrylate, N, N-dimethylami A (meth) acrylate, (meth) acrylate and the like can be given one morpholine. These compounds can be used individually by 1 type or in mixture of 2 or more types.

It is preferable that the circuit connection material contains at least one compound having two or more (meth) acryloyl groups in the molecule as the component (b), and as the component (b-1), two or more (meth) It is more preferable to contain at least 1 type of compound which has an acryloyl group.

As the component (b), a compound having a (meth) acryloyl group is preferable, and as the component (b), a compound having a functional group polymerized by active radicals such as an allyl group, a maleimide group, and a vinyl group can also be used. Specific examples of the component (b) include N-vinylimidazole, N-vinylpyridine, N-vinylpyrrolidone, N-vinyl formamide, N-vinyl caprolactam, 4,4'-vinylidene bis (N , N-dimethylaniline), N-vinyl acetamide, N, N-dimethylacrylamide, N-isopropylacrylamide, N, N-diethylacrylamide, methylolacrylamide, 4,4'-diphenylmethane Bismaleimide, 3,3'-dimethyl-5,5'-4,4'-diphenylmethanebismaleimide, 1,6-bismaleimide- (2,2,4-trimethyl) hexane, and the like. have.

Moreover, the circuit connection material may contain the radically polymerizable compound which has a phosphate ester structure as (b) component. As a radically polymerizable compound which has a phosphate ester structure, the radically polymerizable compound which has a phosphate ester structure represented by following formula (2-4) is mentioned, for example. By blending these compounds, the adhesion strength to the surface of inorganic materials such as metals is further improved, and a circuit connection material that is more effective for adhesion between circuit electrodes is obtained.

In the formula (2), R ⁵ represents a (meth) acryloyloxy group, R ⁶ represents a hydrogen atom or a methyl group, and w and x each independently represent an integer of 1 to 8. In the formula, R ⁵ , R ⁶ , w and x may be the same or different.

In Formula 3, R ⁷ represents a (meth) acryloyloxy group, and y and z each independently represent an integer of 1 to 8. In the formula, R ⁷ , y and z may be the same or different.

In the formula (4), R ⁸ represents a (meth) acryloyloxy group, R ⁹ represents a hydrogen atom or a methyl group, and a and b each independently represent an integer of 1 to 8.

Specific examples of the radically polymerizable compound having a phosphate ester structure include acid phosphooxyethyl methacrylate, acid phosphooxyethyl acrylate, acid phosphooxypropyl methacrylate, acid phosphooxypolyoxyethylene glycol monomethacryl Rate, acid phosphooxypolyoxypropylene glycol monomethacrylate, 2,2'-di (meth) acryloyloxydiethyl phosphate, EO-modified phosphate dimethacrylate, phosphate-modified epoxy acrylate, and vinyl phosphate. You can.

The content of the radically polymerizable compound having a phosphate ester structure is preferably 0.01 to 10% by mass, more preferably 0.5 to 5% by mass, based on the total amount of the circuit connection material.

Further, as a radically polymerizable compound having a phosphate ester structure, a compound obtained by reacting anhydrous phosphoric acid with 2-hydroxyethyl (meth) acrylate may be used. Examples of the radically polymerizable compound having such a phosphate ester structure include mono (2-methacryloyloxyethyl) acid phosphate and di (2-methacryloyloxyethyl) acid phosphate. Moreover, the compound which has a phosphate ester structure may be used individually by 1 type or in mixture of 2 or more types.

The radically polymerizable compound having a phosphate ester structure may be a component (b-1) or a component (b-2) or a component (b-2).

As described above, the circuit connecting material may also contain, as the component (b), those having a radical polymerizability among the silane coupling agents represented by the formula (1).

Examples of the radical polymerization initiator of the component (c) include compounds that decompose by heating to generate free radicals, and known compounds such as peroxides and azo compounds can be used.

(c) As a component, from the viewpoint of combining stability, reactivity and compatibility, peroxide having a half-life temperature of 90 to 175 ° C for 1 minute and a molecular weight of 180 to 1000 can be suitably used. Here, the "half-life temperature for 1 minute" refers to the temperature at which the half-life becomes 1 minute, and the "half-life" refers to the time until the concentration of the compound decreases to half of the initial value.

(c) As a specific example of a component, 1,1,3,3-tetramethylbutylperoxyneodecanoate, di (4-t-butylcyclohexyl) peroxydicarbonate, di (2-ethylhexyl) per Oxydicarbonate, cumylperoxyneodecanoate, 1,1,3,3-tetramethylbutylperoxyneodecanoate, dilauroyl peroxide, 1-cyclohexyl-1-methylethylperoxyneo Decanoate, t-hexylperoxyneodecanoate, t-butylperoxyneodecanoate, t-butylperoxypivalate, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexa Noate, 2,5-dimethyl-2,5-di (2-ethylhexanoylperoxy) hexane, t-hexylperoxy-2-ethylhexanoate, t-butylperoxy-2-ethylhexanoate , t-butylperoxyneopeptanoate, t-amylperoxy-2-ethylhexanoate, di-t-butylperoxyhexahydroterephthalate, t-amylperoxy-3,5,5-trimethylhexa Noate, 3-hydroxy-1,1-dimethylbutylperoxy Odecanoate, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, t-amylperoxyneodecanoate, t-amylperoxy-2-ethylhexanoate, 3- Methylbenzoylperoxide, 4-methylbenzoylperoxide, di (3-methylbenzoyl) peroxide, dibenzoylperoxide, di (4-methylbenzoyl) peroxide, 2,2'-azobis-2,4-dimethyl Valeronitrile, 1,1'-azobis (1-acetoxy-1-phenylethane), 2,2'-azobisisobutyronitrile, 2,2'-azobis (2-methylbutyronitrile) , Dimethyl-2,2'-azobisisobutyronitrile, 4,4'-azobis (4-cyanovaleric acid), 1,1'-azobis (1-cyclohexanecarbonitrile), t-hex Silperoxyisopropyl monocarbonate, t-butylperoxymaleic acid, t-butylperoxy-3,5,5-trimethylhexanoate, t-butylperoxylaurate, 2,5-dimethyl-2, 5-di (3-methylbenzoylperoxy) hexane, t-butylperoxy-2-ethylhexyl monocarbonate, t-hexylperoxybenzo Ytite, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, t-butylperoxybenzoate, dibutylperoxytrimethyl adipate, t-amylperoxy normal octoate, t-amylperoxyyi And Sononanoate, t-amylperoxybenzoate, and the like. In addition, as the component (c), one type may be used alone, or two or more types of compounds may be mixed and used.

As the component (c), a compound that generates radicals by light irradiation (for example, light irradiation with a wavelength of 150 nm to 750 nm) can also be used.

As such a compound, for example, Photoinitiation, Photopolymerization, and Photocuring, J.-P. The α-acetoaminophenone derivatives and phosphine oxide derivatives described in Fouassier, Hanser Publishers (1995), p17 to p35 are more preferable because of their high sensitivity to light irradiation. These compounds may be used alone or in combination with the above peroxide or azo compounds.

In order to suppress corrosion of the circuit electrode of the circuit member, the amount of chlorine ions and organic acids contained in the component (c) is preferably 10000 ppm by mass or less, and more preferably 5000 ppm by mass or less, respectively. Moreover, since the corrosion of a circuit electrode is fully suppressed when it is below this upper limit, the amount of chlorine ions and organic acids contained in component (c) may be 500 ppm by mass or more.

Moreover, it is preferable that (c) component has a mass retention rate of 20 mass% or more after leaving it open for 24 hours under normal pressure at room temperature (25 ° C). According to the component (c) having such a mass retention ratio, the storage stability of the circuit connection material is further improved. In addition, the mass retention rate can be measured by measuring the weight before and after standing.

The content of the component (c) is preferably 0.1 to 30% by mass, more preferably 1 to 20% by mass based on the total amount of the circuit connection material. When the content of the component (c) is within the above range, the reaction rate and long pot life for obtaining sufficient adhesion can be achieved at a higher level.

As the inorganic fine particles of the component (d), known inorganic fine particles can be used without particular limitation. Examples of the component (d) include metal oxide fine particles such as silica fine particles, alumina fine particles, silica-alumina fine particles, titania fine particles, and zirconia fine particles. In addition, (d) component can be used individually by 1 type or in mixture of 2 or more types.

(d) It is preferable that the average particle diameter of a component is less than 1 micrometer, and it is more preferable that it is 0.1-0.5 micrometer. In addition, the average particle diameter referred to herein is the long-axis mode diameter when present in the circuit connecting material. The average primary particle diameter of the component (d) is preferably 100 nm or less, and more preferably 10 to 30 nm. In addition, in this specification, an average particle diameter shows the value measured by image analysis.

As the component (d), fine particles having a surface modified with an organic group can be suitably used from the viewpoint of excellent dispersibility. As an organic group, a dimethylsiloxane group, diphenylsiloxane group, etc. are mentioned, for example.

The content of the component (d) is preferably 5 to 30% by mass, more preferably 10 to 20% by mass, based on the total amount of the circuit connection material. When the content of the component (d) is within the above range, the connection resistance between circuit electrodes to be connected can be further reduced, and the effect of the present invention is further remarkably exhibited.

As described above, the silane coupling agent represented by the formula (1) may be blended into the circuit connecting material as part of the component (b), or may be blended into the circuit connecting material as components other than the components (a) to (d). have.

<Formula 1>

In Formula 1, R ¹ , R ² and R ³ each independently represent a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, an alkoxycarbonyl group having 1 to 5 carbon atoms, or an aryl group, and R ¹ and R At least one of ² and R ³ is an alkoxy group having 1 to 5 carbon atoms, and R ⁴ is (meth) acryloyl group, vinyl group, isocyanate group, imidazole group, mercapto group, amino group, methylamino group, dimethylamino group, benzylamino group , Phenylamino group, cyclohexylamino group, morpholino group, piperazino group, ureido group or glycidyl group, n represents an integer of 1 to 10.

When R ⁴ in Formula 1 is a (meth) acryloyl group or a vinyl group, a silane coupling agent is included in the component (b).

R ¹ , R ² and R ³ are preferably a methyl group, an ethyl group, a methoxy group or an ethoxy group, and more preferably a methoxy group or an ethoxy group.

R ⁴ is preferably a (meth) acryloyl group, a glycidyl group, a mercapto group, or a vinyl group, and more preferably a (meth) acryloyl group or a glycidyl group.

The content of the silane coupling agent is preferably 0.1 to 10% by mass, more preferably 0.25 to 5% by mass based on the total amount of the circuit connection material. When the content of the silane coupling agent is within the above range, generation of peeling bubbles at the interface between the circuit member and the connection member can be significantly suppressed, and a longer life time can be secured.

The circuit connection material of this embodiment may contain components other than the above. For example, a stabilizer may be added to the circuit connecting material for reasons such as control of the curing rate and imparting storage stability. Examples of the stabilizer include quinone derivatives such as benzoquinone and hydroquinone; Phenol derivatives such as 4-methoxyphenol and 4-t-butyl catechol; Aminooxyl derivatives such as 2,2,6,6-tetramethylpiperidine-1-oxyl and 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl; Hindered amine derivatives, such as tetramethyl piperidyl methacrylate, etc. can be used suitably.

When the circuit connection material contains a stabilizer, the content of the stabilizer is preferably 0.01 to 15% by mass based on the total amount of the circuit connection material, and more preferably 0.05 to 10% by mass. When the content of the stabilizer is less than 0.01% by mass, the addition effect may not be sufficiently obtained, and if it exceeds 15% by mass, the polymerization reaction is inhibited, and the low-temperature rapid-curing property may be poor.

In addition, organic fine particles may be added to the circuit connection material of this embodiment for the purpose of stress relaxation and improvement of heat resistance. As the organic fine particles, known organic fine particles can be used without particular limitation.

Examples of the organic fine particles include silicon fine particles, methacrylate-butadiene-styrene fine particles, acrylic-silicone fine particles, polyamide fine particles, and polyimide fine particles. The organic fine particles may have a uniform structure or a core-shell structure.

When the circuit connection material contains organic fine particles, the content of the organic fine particles is preferably 1.5 to 20% by mass, more preferably 2 to 15% by mass, based on the total amount of the circuit connection material.

Conductive particles may be dispersed in the circuit connecting material of the present embodiment. Thereby, it is possible to impart conductivity or anisotropy to the circuit connection material, and such a circuit connection material can be more suitably used for connection purposes between circuit members having circuit electrodes and the like. Further, by connecting with such a circuit connection material, the connection resistance between the connected circuit electrodes can be sufficiently reduced.

That is, the present invention may be an anisotropic conductive adhesive containing a circuit connecting material and conductive particles dispersed in the circuit connecting material. In addition, in this specification, "a total amount of circuit connection material" does not contain electroconductive particle.

Examples of the conductive particles include metal particles containing a metal such as Au, Ag, Pd, Ni, Cu, solder, carbon particles, and the like. Further, the conductive particles may be particles containing non-conductive materials such as glass, ceramics, plastics, etc., and the nucleus may be coated with conductive materials such as metal, metal particles, and carbon.

Moreover, as electroconductive particle, a heat-melting metal particle is preferable. Since such conductive particles have deformability due to heat and pressure, when connecting circuit members, the contact area between the conductive particles and the electrode increases, and the connection reliability between the circuit members tends to be improved.

The blending amount of the conductive particles is preferably 0.1 to 30% by volume relative to the total volume of the anisotropic conductive adhesive, and more preferably 0.1 to 10% by volume. When the compounding amount of the conductive particles is less than 0.1% by volume, the conductivity tends to be inferior, and when it exceeds 30% by volume, a short circuit between the circuit electrodes tends to occur. Moreover, the compounding quantity of electroconductive particle is determined based on the volume at 23 degreeC of each component of the circuit connection material before hardening. The volume of each component can be determined by converting the mass into volume using specific gravity. In addition, without dissolving or swelling the component to be measured for volume, an appropriate solvent (water, alcohol, etc.) that can infiltrate the component well is placed in a measuring cylinder, etc., and the volume of the component to be measured is increased. Can also be determined as the volume of the component.

The circuit connection material of this embodiment can be manufactured by mixing each of the components described above without using a solvent. Moreover, each component mentioned above can also be manufactured by mixing together with the solvent which can melt | dissolve or disperse the said each component.

The circuit connection material of this embodiment can be used in the form of a film. By setting it as a film shape, handling property of a circuit connection material becomes very favorable.

Specifically, for example, by applying a solution prepared by adding a solvent or the like to the circuit connection material as necessary, on a peelable substrate such as a fluorine resin film, polyethylene terephthalate film, or release paper, and then removing the solvent , A film-like circuit connection material (hereinafter referred to as "film-like adhesive" in some cases) can be obtained. In addition, a film-like adhesive can also be obtained by impregnating a base material such as a nonwoven fabric with a solution prepared by adding a solvent or the like to the circuit connection material, and placing it on a peelable base material and removing the solvent. In addition, by mixing the conductive particles during mixing, the conductive particles can be dispersed in the film adhesive.

As a solvent, methyl ethyl ketone and toluene can be used suitably, for example.

1 is a schematic cross-sectional view showing an embodiment of a circuit connecting material of the present invention. The film adhesive 1 shown in FIG. 1 is formed by molding the circuit connection material into a film. The film adhesive 1 is easy to handle and can be easily installed on an adherend. Therefore, according to the film adhesive 1, a connection operation can be performed easily.

The film-like adhesive 1 may have a multi-layer structure (not shown) including two or more layers. Further, conductive particles (not shown) may be dispersed in the film-like adhesive 1. The film adhesive in which the conductive particles are dispersed can be suitably used as an anisotropic conductive film adhesive. That is, the present invention may be an anisotropic conductive film-like adhesive containing the circuit connecting material and conductive particles.

As a connection method of an adherend using the circuit connection material of this embodiment (for example, the film adhesive 1), the connection method which used heating and pressurization together is mentioned, for example. In this method, the heating temperature is preferably 100 to 250 ° C. The pressure is not particularly limited so long as it does not damage the adherend, but is generally preferably 0.1 to 10 MPa. It is preferable to perform this heating and pressurization in the range of 0.5 second to 120 seconds. Moreover, according to the said circuit connection material, the to-be-adhered body can fully be adhered by heating and pressurizing for 10 seconds on conditions of 150-200 degreeC of heating temperature and 3 MPa of pressure, for example.

The circuit connection material of the present embodiment can be suitably used as a heterogeneous adherend adhesive having a different thermal expansion coefficient. Specifically, for example, as an anisotropic conductive adhesive, a silver paste, a circuit connecting material represented by a silver film, or the like, or a semiconductor device adhesive material represented by a CSP elastomer, a CSP underfill material, a LOC tape, or the like, Can be used.

The circuit connection material of this embodiment may be formed in a film form on one surface of a film base material.

That is, the present invention may be an adhesive film provided on a film substrate and one side of the film substrate and provided with a film-like adhesive comprising the circuit connection material. Such an adhesive film can be used suitably as the above-mentioned film adhesive by peeling a film base material.

In the adhesive film, since the film-like adhesive contains a circuit connecting material having the above-described specific configuration, even when the film-like adhesive is wound in a reel so that the film-like adhesive comes into contact, the film on the other side of the film-based Transfer of the phase adhesive is sufficiently suppressed.

When the same winding body is made of a conventional circuit connection material, the circuit connection material may sometimes seep from between the film substrates, since in this adhesive film, the film-like adhesive contains a circuit connection material having the specific configuration described above. , Even in the case of winding in a reel form, exudation of the film-like adhesive from between the film-like substrates is sufficiently suppressed. Therefore, the adhesive film can be appropriately stored as a reel-wound rolled body, and the handleability is further excellent.

As a film base material, polyethylene terephthalate, polycarbonate, polypropylene is mentioned, for example.

The adhesive film can be, for example, 5 mm or less in width (preferably 0.5 to 5.0 mm) and 1 m or more in length (preferably 10 to 500 m). Since the adhesive film of such a size is preferably wound and stored in a reel, the above-described effect becomes particularly effective.

The adhesive film may further include a protective film provided on the film adhesive. Since the protective film needs to be peeled before connecting the adherend, it is preferable to have excellent peelability.

Hereinafter, an example in the case of connecting circuit members having circuit electrodes on the main surface of the circuit board using the circuit connection material of the present embodiment will be described. In the following description, the case where the conductive particles are dispersed in the circuit connection material to give an anisotropic conductive adhesive is illustrated, but even when the conductive particles are not dispersed in the circuit connection material, the circuit members can be connected by the same method. have.

The anisotropically conductive adhesive is disposed between circuit electrodes facing each other on the circuit board, and heated and pressed, so that electrical connection between the opposite circuit electrodes and adhesion between the circuit boards can be performed to connect the circuit members.

As a circuit board, For example, a glass board; And flexible substrates containing organic materials such as polyimide, polyethylene terephthalate, and polycarbonate. Here, as the circuit board, the effect of the present invention is particularly great when one is a glass substrate and the other is a flexible substrate. Moreover, as a circuit board, the board | substrate which combined inorganic and organic materials, such as glass / epoxy, can also be used.

2 is a schematic cross-sectional view showing an embodiment of the circuit connection structure of the present invention. The circuit connection structure shown in FIG. 2 includes a first circuit member 20 and a second circuit member 30 that face each other, and is between the first circuit member 20 and the second circuit member 30. In, the connecting member 10 which connects these is provided.

The first circuit member 20 includes a circuit board (first circuit board) 21 and a circuit electrode (first circuit electrode) 22 formed on the main surface 21a of the circuit board 21. . In addition, an insulating layer (not shown) may be formed on the main surface 21a of the circuit board 21 in some cases.

Meanwhile, the second circuit member 30 includes a circuit board (second circuit board) 31 and a circuit electrode (second circuit electrode) 32 formed on the main surface 31a of the circuit board 31. Doing. In addition, an insulating layer (not shown) may be formed on the main surface 31a of the circuit board 31 in some cases.

The first and second circuit members 20 and 30 are not particularly limited as long as electrodes requiring electrical connection are formed. Specifically, glass or plastic substrates with electrodes formed of ITO, IZO, etc. used in liquid crystal displays, printed wiring boards, ceramic wiring boards, flexible wiring boards, semiconductor silicon chips, and the like are used. do. As described above, in the present embodiment, a printed wiring board, a material such as polyimide, or the like containing an organic material, a metal such as copper, aluminum, indium tin oxide (ITO), silicon nitride (SiN _x ), silicon dioxide (SiO ₂ ), etc. Circuit members having various surface states, such as inorganic materials, may be used.

The connecting member 10 contains an insulating material 11 and conductive particles 7. The electroconductive particle 7 is arrange | positioned not only between the opposing circuit electrode 22 and the circuit electrode 32, but also between the main surfaces 21a, 31a. In this circuit connection structure, the circuit electrodes 22 and 32 are electrically connected through the conductive particles 7. That is, the conductive particles 7 are in direct contact with both of the circuit electrodes 22 and 32.

Here, the conductive particles 7 are the conductive particles described above, and the insulating material 11 is a cured product of the circuit connection material.

In the circuit connection structure, as described above, the opposite circuit electrodes 22 and circuit electrodes 32 are electrically connected through the conductive particles 7. For this reason, the connection resistance between the circuit electrodes 22 and 32 is sufficiently reduced. Therefore, the current flow between the circuit electrodes 22 and 32 can be smoothed, and the function of the circuit can be sufficiently exhibited. In addition, when the connecting member 10 does not contain the electroconductive particle 7, the circuit electrode 22 and the circuit electrode 32 are directly contacted and electrically connected.

Since the connecting member 10 is composed of a cured product of the circuit connecting material and conductive particles, the bonding strength of the connecting member 10 to the circuit member 20 or 30 is sufficiently high, and thus a reliability test (high temperature and high humidity test) Even after), stable performance (good adhesion strength and connection resistance) can be maintained.

Next, an example of a method for manufacturing the above-described circuit connection structure will be described with reference to FIG. 3. First, the above-described first circuit member 20 and the film-like adhesive 40 are prepared (see FIG. 3 (a)). The film adhesive 40 is formed by molding a circuit connecting material in which conductive particles are dispersed into a film, and includes a circuit connecting material 5 and conductive particles 7. Further, even when the conductive particles 7 are not dispersed in the film-like adhesive 40 (that is, when the film-like adhesive 40 includes the circuit connecting material 5), the film-like adhesive is an insulating adhesive As it can be used for anisotropic conductive bonding, the circuit connection material is sometimes referred to as NCP (Non-Conductive Paste). In addition, when the conductive particles 7 are dispersed in the circuit connecting material 5, the material may be referred to as ACP (Anisotropic Conductive Paste).

The thickness of the film adhesive 40 is preferably 6 to 50 μm. When the thickness of the film-like adhesive 40 is less than 6 μm, the circuit connection material 5 tends to be insufficient in filling between the circuit electrodes 22 and 32. On the other hand, when it exceeds 50 µm, the circuit connecting materials 5 between the circuit electrodes 22 and 32 cannot be sufficiently removed, and there is a tendency that it is difficult to secure conduction between the circuit electrodes 22 and 32.

Subsequently, the film-like adhesive 40 is placed on the surface where the circuit electrode 22 of the first circuit member 20 is formed. In addition, when the film-like adhesive 40 is attached on a support (not shown), the film-like adhesive 40 is directed toward the first circuit member 20, and the first circuit member 20 Put on the table. At this time, the film-like adhesive 40 is in the form of a film and is easy to handle. For this reason, the film adhesive 40 can be easily interposed between the 1st circuit member 20 and the 2nd circuit member 30, and the 1st circuit member 20 and the 2nd circuit member 30 can be interposed. Connection work can be performed easily.

Then, the film-like adhesive 40 is pressed in the direction of arrows A and B in Fig. 3A to temporarily connect the film-like adhesive 40 to the first circuit member 20 (Fig. 3B) Reference). At this time, you may pressurize while heating. However, the heating temperature is set to a temperature lower than the temperature at which the film adhesive 40 (the circuit connection material 5 constituting the film adhesive 40) does not cure.

Subsequently, as shown in FIG. 3C, the second circuit member 30 is placed on the film-like adhesive 40 with the second circuit electrode 32 facing the first circuit member 20. Put on. In addition, when the film adhesive 40 is attached on a support (for example, the above-described film-like substrate (not shown)), the second circuit member 30 is removed from the film adhesive after the support is peeled off. 40) Put it on. At this time, after the first and second circuit electrodes 22 and 23 are aligned to face each other, the second circuit member 30 can be temporarily fixed by heating and pressing from the second circuit member 30. By doing so, it is possible to suppress the positional displacement of the electrode during the subsequent main connection. The heating temperature at the time of temporary fixing is set to a temperature lower than the temperature at which the circuit connecting material 5 in the film-like adhesive 40 does not cure, and the time from alignment of the position to completion of the temporary fixing is preferably 5 seconds or less to shorten the throughput. Do.

And while heating the film adhesive 40, it presses through the 1st and 2nd circuit members 20 and 30 in the arrow A and B direction of FIG. 3 (c). The heating temperature at this time is the temperature at which the polymerization reaction can be started. In this way, the film-like adhesive 40 is cured and the main connection is performed, whereby a circuit connection structure as shown in Fig. 2 is obtained.

Here, as described above, the connection conditions are preferably 100 to 250 ° C. for heating temperature, 0.1 to 10 MPa for pressure, and 0.5 to 120 seconds for connection time. These conditions are appropriately selected according to the application to be used, the circuit connection material, and the circuit member, and may be post-cured if necessary.

By manufacturing the circuit connection structure as described above, in the circuit connection structure obtained, it is possible to make the conductive particles 7 contact both of the opposing circuit electrodes 22, 32, thereby making the circuit electrodes 22, 32 The connection resistance between can be sufficiently reduced.

Further, by heating the film-like adhesive 40, the circuit connection material 5 is cured to become an insulating material 11 in a state where the distance between the circuit electrode 22 and the circuit electrode 32 is sufficiently reduced. The first circuit member 20 and the second circuit member 30 are firmly connected through the connection member 10. That is, in the obtained circuit connection structure, since the connection member 10 is provided with the insulating material 11 containing the above-described circuit connection material, the connection member 10 is adhered to the circuit member 20 or 30. While the strength is sufficiently high, it is possible to sufficiently reduce the connection resistance between the electrically connected circuit electrodes. In addition, even when placed in a high-temperature and high-humidity environment for a long period of time, the occurrence of peeling bubbles at the interface between the circuit members 20 and 30 and the connection member 10 can be sufficiently suppressed. The increase can be sufficiently suppressed.

The preferred embodiments of the present invention have been described above, but the present invention is not limited to the above embodiments.

For example, the present invention is a use of a composition containing the thermoplastic resin, the radically polymerizable compound, the radical polymerization initiator, and the inorganic fine particles as a circuit connecting material for electrically connecting two circuit members facing each other. You may. In addition, the present invention is used for the production of a circuit connecting material for electrically connecting two circuit members facing each other of the composition containing the thermoplastic resin, the radically polymerizable compound, the radical polymerization initiator, and the inorganic fine particles. You can also say

In this use, the content of the radically polymerizable compound is 40% by mass or more based on the total amount of the composition, and the content of the compound having a molecular weight of 1000 or less in the radically polymerizable compound is 15% by mass based on the total amount of the composition. Below, the content of the inorganic fine particles is 5 to 30% by mass based on the total amount of the composition, and the composition contains at least the compound represented by the formula (1).

According to this application, even when the circuit member is left in a high-temperature and high-humidity environment after being connected to the radical polymerization type, the generation of peeling bubbles at the interface with the circuit member can be sufficiently suppressed and sufficient connection reliability can be maintained. The above-mentioned circuit connection material can be obtained.

Example

Hereinafter, the present invention will be described in more detail by examples, but the present invention is not limited to the examples.

(Production Example 1: Synthesis of thermoplastic resin)

To a separable flask equipped with a reflux cooler, thermometer, and stirrer, 1000 parts by mass of polypropylene glycol (Mn = 2000) as a diol having an ether bond and 4000 parts by mass of methyl ethyl ketone as a solvent were added and stirred at 40 ° C for 30 minutes. . After the solution was heated up to 70 ° C, 1 part by mass of dimethyltin laurate was added as a catalyst, and then 125 parts by mass of 4,4-diphenylmethane-diisocyanate as a diisocyanate compound with respect to this solution was methyl ethyl ketone 125 The solution dissolved in the mass part was added dropwise over 1 hour.

Thereafter, stirring was continued at 70 ° C until the absorption peak of NCO (isocyanate group) could not be seen with an infrared spectrophotometer, thereby obtaining a methyl ethyl ketone solution of the polyurethane resin. This solution was adjusted to a solid content concentration of 30% by mass, and used in Examples and Comparative Examples.

The weight average molecular weight of the obtained polyurethane resin in terms of polystyrene was 320000 as a result of measurement by GPC. GPC analysis conditions are shown in Table 1 below.

(Production Example 2: Synthesis of radically polymerizable compounds)

In a 2-liter four-necked flask equipped with a thermometer, stirrer, inert gas inlet and reflux cooler, 4000 parts by mass of polycarbonate diol (manufactured by Aldrich, number average molecular weight 2000), 238 parts by mass of 2-hydroxyethyl acrylate , 0.49 parts by mass of hydroquinone monomethyl ether and 4.9 parts by mass of tin-based catalyst were added, heated to 70 ° C, and 666 parts by mass of IPDI (isophorone diisocyanate) was added dropwise over 3 hours to react. After completion of the dropwise addition, the reaction was continued for 15 hours, and when the NCO% (the amount of the isocyanate group relative to the urethane group) became 0.2% or less, the reaction was terminated to obtain a urethane acrylate. As a result of analysis by GPC, the obtained urethane acrylate had a weight average molecular weight of 8500. In addition, GPC analysis was performed on the conditions of Table 1.

(Production Example 3: Preparation of conductive particles)

On the surface of the polystyrene particles, a layer containing nickel with a thickness of 0.2 µm was formed, and then a layer containing gold was formed on the surface of the layer containing nickel to have a thickness of 0.04 µm. Thus, conductive particles having an average particle diameter of 5 µm were produced.

(Examples 1 to 6 and Comparative Examples 1 to 4)

(a) As the thermoplastic resin of the component, a solution having a solid content concentration of 40% by mass, in which 40 g of phenoxy resin (PKHC, trade name of Union Carbide, weight average molecular weight (45000, indicated as "PKHC" in the table)) was dissolved in 60 g of methyl ethyl ketone, And a solution having a solid content concentration of 30% by mass of the polyurethane resin (referred to as "PU" in the table) obtained in Production Example 1.

Moreover, as a radically polymerizable compound of (b) component, the urethane acrylate obtained by manufacture example 2 (represented as "UA" in a table), cyclohexyl acrylate (manufactured by Toa Kose Co., Ltd., shown as "CHA" in a table) ), 2- (meth) acryloyloxyethyl phosphate (light ester P-2M, manufactured by Kyoeisha Co., Ltd., indicated as "P-2M" in the table), and 3-methacryloxypropyl trimethoxy Silane (KBM503, Shin-Etsu Chemical Co., Ltd. trade name, silane coupling agent, "KBM" in the table) was used.

In addition, as the radical polymerization initiator of the component (c), t-hexylperoxy-2-ethylhexanoate (perhexyl O, manufactured by Yushi Seching Co., Ltd., indicated as "peroxide" in the table) was used.

Further, as the inorganic fine particles of the component (d), 10 g of R711 (brand name manufactured by Nippon Aerosil Co., Ltd., indicated as "R711" in the table) was dispersed in a mixed solvent of 45 g of toluene and 45 g of ethyl acetate, and a solution of 10% by mass It was used as.

Each of the above components was blended so as to have a solid content weight ratio shown in Table 2, and then, the conductive particles obtained in Production Example 3 were blended and dispersed in a volume of 1.5% by volume relative to the total volume of the adhesive component to obtain a coating solution. The obtained coating solution was applied to a polyethylene terephthalate (PET) film having a thickness of 50 µm using a coating apparatus, followed by hot air drying at 70 ° C. for 10 minutes to obtain a film adhesive having a thickness of 16 µm.

Content of the radically polymerizable compound in the film adhesive of each Example and Comparative Example, content of the radically polymerizable compound ((b-1) component) whose molecular weight exceeds 1000, and the radically polymerizable compound having a molecular weight of 1000 or less ((b The content of the -2) component and the content of the inorganic fine particles were calculated from the respective blending amounts and were as described in Table 3 (all of the circuit-connected materials (components other than the conductive particles of the film-like adhesive), the mass percentage based on the total amount). Moreover, 3-methacryloxypropyl trimethoxysilane of a silane coupling agent is contained in (b-2) component.

(Examples 6 to 10 and Comparative Examples 6 to 10)

Using the film-like adhesives of Examples 1 to 5 and Comparative Examples 1 to 5, the connecting structures of Examples 6 to 10 and Comparative Examples 6 to 10 were produced.

Specifically, the film-like adhesive was transferred to a glass substrate (thickness of 1.1 mm) on which a thin film of indium oxide (ITO) having a thickness of 0.2 µm was formed at a temperature of 70 ° C. for 1 MPa and 2 seconds. Subsequently, this glass substrate and 500 flexible copper circuits having a line width of 75 µm, a pitch of 150 µm, and a thickness of 18 µm were placed on a polyimide with an epoxy resin adhesive so as to face each other through a film-like adhesive. , Heat pressurization was performed for 10 seconds at 3 MPa at a temperature of 160 ° C using a thermocompression device (heating method: constant heat type, manufactured by Toray Engineering Co., Ltd.). Thus, a connection body (circuit connection structure) was obtained in which the FPC substrate and the glass substrate (ITO substrate) were connected by a cured product (connection member) of a film-like adhesive over a width of 2 mm.

(Evaluation of circuit connection structure 1: Evaluation of initial connection resistance)

For the circuit connection structures obtained in Examples and Comparative Examples, the resistance values (connection resistance) between adjacent circuits were respectively measured with a multimeter. The average of 37 points of resistance between adjacent circuits was used as the evaluation result of the initial connection resistance. Table 4 shows the evaluation results.

(Evaluation of circuit connection structure 2: Evaluation of initial adhesion)

For the circuit connection structures obtained in Examples and Comparative Examples, the adhesive force between the connecting member and the FPC board was measured by a 90-degree peeling method according to JIS-Z0237, and the measured values were used as evaluation results of the initial adhesive force. In addition, as a measuring device for the adhesive force, Tensilon UTM-4 manufactured by Toyo Baldwin Co., Ltd. (peel rate 50 mm / min, 25 ° C.) was used. Table 4 shows the evaluation results.

(Evaluation of circuit connection structure 3: Characteristic evaluation after high temperature and high humidity test)

The circuit connection structures obtained in Examples and Comparative Examples were held at 85 ° C and 85% RH for 250 hours to obtain measurement samples. About the obtained sample, connection resistance and adhesive force were evaluated by the method similar to the said evaluation 1 and 2 above. Table 4 shows the evaluation results.

In addition, the obtained sample was examined for the presence or absence of peeling at the interface between the connecting member and the FPC substrate and the interface between the connecting member and the glass substrate using a microscope (trade name: ECLIPSE L200, manufactured by Nikon Corporation). It was evaluated as "A" that there was no interfacial peeling, "B" that there was little interfacial peeling, and "C" that interfacial peeling occurred to such an extent that there was a practical problem. Table 4 shows the evaluation results.

As apparent from the results shown in Table 4, the circuit connection structures obtained in Examples 6 to 10 exhibited resistance values of 3 Ω or less in both cases after the initial and high temperature and high humidity tests, and peeled bubbles at the interface between the connection member and the circuit member The back did not occur.

On the other hand, the circuit connecting structure of Comparative Example 6 obtained using the film-like adhesive of Comparative Example 1 that does not contain inorganic fine particles, and the Comparative Example obtained using the film-like adhesive of Comparative Example 2 having an inorganic fine particle content of less than 5% by mass. In the circuit connection structure of 7, after the high-temperature and high-humidity test, the connection resistance was remarkably increased, the adhesive strength was decreased, and peeling was seen at the interface between the connection member and the circuit member. In addition, the circuit-like structure of Comparative Example 8 obtained using the film-like adhesive of Comparative Example 3 in which the content of the component (b-2) exceeds 15% by mass, and the film shape of Comparative Example 5 not containing a silane coupling agent. In the circuit connection structure of Comparative Example 10 obtained using an adhesive, peeling occurred remarkably at the interface between the connection member and the circuit member after the high temperature and high humidity test. In addition, in the circuit connecting structure of Comparative Example 9 obtained by using the film-like adhesive of Comparative Example 4 that does not contain inorganic fine particles and the content of the component (b-2) exceeds 15% by mass, the connection resistance increases, The adhesive strength was lowered, and peeling occurred remarkably at the interface between the connecting member and the circuit member.

(Examples 11 to 15 and Comparative Examples 11 to 15))

The coating liquids used for the production of the film-like adhesives of Examples 1 to 5 and Comparative Examples 1 to 5 were respectively coated on a polyethylene terephthalate (PET) film having a thickness of 50 µm for 10 m, and dried at 70 ° C. for 10 minutes with hot air. Was performed, and a film-like adhesive having a thickness of 16 μm was formed on the PET film, thereby obtaining an adhesive film comprising the PET film and the film-like adhesive.

The obtained adhesive film was cut to a width of 2 mm, and wound into a reel shape having an inner diameter of 66 mm to obtain a wound body of the adhesive film.

(Evaluation of the winding body of the adhesive film)

A load of 75 g was fixed to the distal end of the wound body of the obtained adhesive film, and the load was allowed to stand under a load of 6 hours under a 30 ° C atmosphere. The wound body after standing was observed, and the presence or absence of exudation of the film-like adhesive from between the PET films was confirmed. Moreover, the adhesive film was taken out from the wound body after standing, and the presence or absence of transfer of the film adhesive to the back side of PET film was confirmed. The case where both the seepage and the warrior were not seen was evaluated as "A", the case where the warrior was not seen but the seepage was visible was evaluated as "B", and the case where both the seepage and the warrior were seen were evaluated as "C". Table 5 shows the evaluation results.

As apparent from the results shown in Table 5, in the adhesive films obtained in Examples 11 to 15, no seepage of the film adhesive was observed even after leaving for 6 hours under a load of 75 g at 30 ° C, and transfer to the back side of the PET film was also seen. Did. On the other hand, in Comparative Examples 11 to 13, seepage of the film-like substrate from between the PET films was observed in the winding body. In addition, in Comparative Examples 11 and 14, as well as seeping, transfer of the film-like adhesive to the back side of the PET film was seen.

1: Film adhesive
5: circuit connection material
7: conductive particles
10: connecting member
11: insulating material
20: first circuit member
21: circuit board (first circuit board)
21a: Main surface
22: circuit electrode (first circuit electrode)
30: second circuit member
31: circuit board (second circuit board)
31a: Main surface
32: circuit electrode (second circuit electrode)
40: film-like adhesive

Claims (1)

As a circuit connecting material for electrically connecting two circuit members facing each other of a composition containing a thermoplastic resin, a radical polymerizable compound, a radical polymerization initiator, and inorganic fine particles,
The content of the radically polymerizable compound is 40% by mass or more based on the total amount of the composition,
The content of the compound having a molecular weight of 1000 or less in the radically polymerizable compound is 15% by mass or less based on the total amount of the composition,
The content of the inorganic fine particles is 5 to 30% by mass based on the total amount of the composition,
Use in which the composition contains at least a compound represented by the following formula (1).
<Formula 1>

[Wherein, R ¹ , R ² and R ³ each independently represent a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, an alkoxycarbonyl group having 1 to 5 carbon atoms, or an aryl group, and R ¹ and R At least one of ² and R ³ is an alkoxy group having 1 to 5 carbon atoms, and R ⁴ is (meth) acryloyl group, vinyl group, isocyanate group, imidazole group, mercapto group, amino group, methylamino group, dimethylamino group, benzylamino group , Represents a phenylamino group, cyclohexylamino group, morpholino group, piperazino group, ureido group or glycidyl group, n represents an integer of 1 to 10]

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