WO2013161713A1

WO2013161713A1 - Circuit connection material, circuit connection structure, adhesive film, and wound body

Info

Publication number: WO2013161713A1
Application number: PCT/JP2013/061658
Authority: WO
Inventors: 直工藤; 松田　和也; 藤縄　貢
Original assignee: 日立化成株式会社
Priority date: 2012-04-25
Filing date: 2013-04-19
Publication date: 2013-10-31
Also published as: KR102329065B1; CN104169389A; JPWO2013161713A1; KR20200045015A; CN104169389B; JP6090311B2; KR20150005516A

Abstract

A circuit connection material for electrically connecting two circuit members facing each other, which contains a thermoplastic resin, radically polymerizable compounds, a radical polymerization initiator and inorganic fine particles. The content of the radically polymerizable compounds is 40% by mass or more based on the total amount of the circuit connection material, and the content of compounds having a molecular weight of 1,000 or less among the radically polymerizable compounds is 15% by mass or less based on the total amount of the circuit connection material. The content of the inorganic fine particles is 5-30% by mass based on the total amount of the circuit connection material. The circuit connection material contains at least a compound represented by formula (1).

Description

Circuit connection material, circuit connection structure, adhesive film and roll

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

In a semiconductor element and a liquid crystal display element, various circuit connection materials have been conventionally used for the purpose of bonding various members in the element. The characteristics required for circuit connection materials are diverse, including adhesiveness, heat resistance, reliability in high temperature and high humidity conditions, and the like.

Examples of adherends to be bonded with circuit connection materials include, for example, printed wiring boards, organic substrates such as polyimide, polyethylene terephthalate and polycarbonate, metal substrates such as copper and aluminum, and ITO, IZO, SiN. And inorganic base materials such as SiO _2, and base materials having various surface states are used. For this reason, the circuit connection material needs to have a molecular design tailored to each adherend (for example, Patent Documents 1 and 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 component of such a thermosetting resin composition, there are a curing agent such as an epoxy resin, a phenol resin having reactivity with the epoxy resin, and a thermal latent catalyst that promotes the reaction between the epoxy resin and the curing agent. Commonly used.

In the actual process, the above circuit connecting material was cured at a temperature of 170 to 250 ° C. for 1 to 3 hours to obtain a desired adhesion. However, with the recent high integration of semiconductor elements and high definition of liquid crystal elements, the pitch between elements and wirings is narrowed, and there is a risk that the peripheral members will be adversely affected by heating during curing.

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

Recently, a radical curable adhesive using an acrylate derivative and / or a methacrylate derivative (hereinafter referred to as a (meth) acrylate derivative) and a peroxide as a radical polymerization initiator has attracted attention. The radical curable adhesive can be cured for a short time because radicals that are reactive species are rich in reactivity (see, for example, Patent Document 2).

Japanese Patent Laid-Open No. 1-113480 International Publication No. 98/44067 Pamphlet

However, in the case of the radical curable adhesive, since the curing shrinkage of (meth) acrylate is larger than that of the epoxy resin, when the connection structure is left in a high temperature and high humidity environment such as 85 ° C. and 85% RH, In many cases, peeling bubbles are generated at the interface between the circuit member and the circuit connecting material. In order to solve this problem, if the amount of (meth) acrylate is reduced, even if the peeling at the interface between the circuit member and the circuit connection material can be suppressed, the adhesive strength is reduced, or the electrical connection between the opposing electrodes It becomes impossible to maintain.

The present invention has been made in view of the above-mentioned problems of the prior art, and is a radical polymerization type, and even when the circuit member is left in a high-temperature and high-humidity environment after being connected, peeling bubbles at the interface with the circuit member are present. Circuit connection material capable of sufficiently suppressing the occurrence of the above and maintaining sufficient connection reliability, a circuit connection structure manufactured using the circuit connection material, and an adhesive film comprising a connection material layer made of the circuit connection material And a wound body of the adhesive film.

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

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

Since the circuit connecting material of the present invention is a radical curing type, circuit members can be bonded together at a 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 being connected, generation of peeling bubbles at the interface with the circuit member is sufficiently suppressed, and sufficient connection reliability is achieved. 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 connecting material of the present invention, the average particle size of the inorganic fine particles may be less than 1 μm.

In the circuit connection material of the present invention, conductive particles may be dispersed. By dispersing the conductive particles, it is possible to impart conductivity or anisotropic conductivity to the circuit connection material. Such a circuit connection material can be used for connecting circuit members having circuit electrodes to each other. It can be used suitably. Moreover, the connection resistance between the connected circuit electrodes can be sufficiently reduced by connecting with such a circuit connection material.

That is, the present invention may be an anisotropic conductive adhesive containing the circuit connection material and conductive particles dispersed in the circuit connection material. In this specification, “total amount of circuit connecting material” does not include conductive particles.

The shape of the circuit connecting material of the present invention can be a film. Such a circuit connection material is excellent in handleability.

In the present invention, at least one of the two circuit members may be a glass substrate. Further, 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 arranged opposite to each other and a cured product of the circuit connection material, and the circuit electrodes interposed between the pair of circuit members are electrically connected to each other. A circuit connection structure including a connection member for connecting the circuit members to each other is provided.

In the circuit connection structure of the present invention, since the circuit members are bonded to each other by the connection member containing the cured product of the circuit connection material, the interface between the circuit member and the connection member even when left under high temperature and high humidity conditions The generation of exfoliated bubbles in is sufficiently suppressed, and sufficient connection reliability is maintained.

The present invention also provides an adhesive film comprising a film base material and a film adhesive containing the circuit connecting material provided on one surface of the film base material. Since such an adhesive film is provided with the film adhesive containing the said circuit connection material, it can be utilized suitably for the connection of circuit members. In addition, the adhesive film of the present invention can be stored in a reel shape.

When a conventional circuit connection material is applied on one side of a film base material and wound in a reel, the film adhesive may be transferred onto the other side of the film base material and cannot be used effectively. is there. On the other hand, in the adhesive film of the present invention, since the film adhesive contains the circuit connection material, even when the film adhesive is rolled up in a reel shape, the transfer of the film adhesive on the other surface of the film substrate is performed. Sufficiently suppressed.

The present invention further provides a wound body obtained by winding the adhesive film in a reel shape. The wound body of this invention can be utilized suitably for the connection of circuit members. Moreover, in the wound body of this invention, transfer of the film adhesive on the other surface of a film base material is fully suppressed.

Further, the present invention is an application of a composition containing a thermoplastic resin, a radical polymerizable compound, a radical polymerization initiator and inorganic fine particles as a circuit connection material for electrically connecting two opposing circuit members. It can also be said. Here, the content of the radical polymerizable compound is 40% by mass or more based on the total amount of the composition, and the content of a compound having a molecular weight of 1000 or less among the radical polymerizable compounds is based on the total amount of the composition. And 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). .

The present invention also provides a method for producing a circuit connection material for electrically connecting two opposing circuit members of a composition containing a thermoplastic resin, a radical polymerizable compound, a radical polymerization initiator and inorganic fine particles. It can also be said to be an application for. Here, the content of the radical polymerizable compound is 40% by mass or more based on the total amount of the composition, and the content of a compound having a molecular weight of 1000 or less among the radical polymerizable compounds is based on the total amount of the composition. And 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 these applications, even if the circuit member is a radical polymerization type, even when the circuit member is left in a high-temperature and high-humidity environment after connection, the generation of exfoliated bubbles at the interface with the circuit member can be sufficiently suppressed and sufficient connection reliability can be achieved. Thus, a circuit connection material capable of maintaining the properties can be obtained.

According to the present invention, even when the circuit member is left in a high-temperature and high-humidity environment after being connected, it is possible to sufficiently suppress the generation of exfoliated bubbles at the interface with the circuit member and to ensure sufficient connection reliability. Circuit connection material that can maintain the above, a circuit connection structure manufactured using the circuit connection material, an adhesive film including a connection material layer made of the circuit connection material, and a wound body of the adhesive film are provided. The

It is a schematic cross section which shows one Embodiment of the circuit connection material of this invention. It is a schematic cross section which shows one Embodiment of the connection structure of this invention. (A)-(c) is process drawing which shows a series of processes which connect a circuit member.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings as the case may be. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and redundant description is omitted.

In the present specification, (meth) acrylic acid means acrylic acid or methacrylic acid corresponding thereto, (meth) acrylate means acrylate or methacrylate corresponding thereto, and (meth) acryloyl group means acryloyl group. Or means a methacryloyl group.

The circuit connecting material of the present embodiment can be suitably used for electrically connecting two circuit members facing each other, and is a thermoplastic resin (hereinafter sometimes referred to as “component (a)”). A radical polymerizable compound (hereinafter sometimes referred to as “component (b)”), a radical polymerization initiator (hereinafter sometimes referred to as “component (c)”), and inorganic fine particles (hereinafter referred to as case). (Referred to as “component (d)”).

In this 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 among the components (b) is based on the total amount of the circuit connection material. The content of the component (d) is 5 to 30% by mass.

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

In formula (1), R ¹ , R ² and R ³ are each independently 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, Represents an aryl group, and at least one of R ¹ , R ² and R ³ is an alkoxy group having 1 to 5 carbon atoms, and R ⁴ represents a (meth) acryloyl group, a vinyl group, an isocyanate group, an imidazole group, a mercapto group Represents a group, amino group, methylamino group, dimethylamino group, benzylamino group, phenylamino group, cyclohexylamino group, morpholino group, piperazino group, ureido group or glycidyl group, and n represents an integer of 1 to 10.

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

Since the circuit connecting member of the present embodiment is a radical curing type, the circuit members can be bonded together at a low temperature and in 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, the generation of peeling bubbles at the interface with the circuit member is sufficiently suppressed, and sufficient connection reliability is achieved. Sex is maintained.

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

(A) It is preferable that a component contains at least 1 sort (s) of resin whose glass transition temperature is 25 degreeC or more from a viewpoint which film forming property improves further. Examples of such resins include polyimide resins, polyamide resins, phenoxy resins, poly (meth) acrylate resins, polyester resins, polyurethane resins, and polyvinyl butyral resins. Moreover, (a) component may contain 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 component (a), a siloxane bond or a fluorine substituent (for example, a fluorine atom, a fluorinated alkyl group or a fluorinated aryl group) may be contained.

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

The circuit connecting material preferably 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 5.0 × 10 ³ to 2.0 × 10 ^5. Preferably, it is 1.0 × 10 ⁴ to 1.5 × 10 ⁵ .

Among the components (a), a resin having a glass transition temperature of 25 ° C. or higher has a tendency that the adhesiveness of the circuit connecting material is inferior and film formability is sufficiently obtained when the weight average molecular weight is less than 5.0 × 10 ^3. When the weight average molecular weight exceeds 2.0 × 10 ⁵ , the compatibility with other components of the circuit connecting material may be inferior, and the fluidity of the circuit connecting material may be reduced. On the other hand, according to the resin having the weight average molecular weight within the above range, it is possible to sufficiently suppress the decrease in the adhesive strength and the fluidity of the circuit connecting material, and the connection reliability can be further improved.

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

The circuit connection material may contain a known rubber component as the component (a). By adding a rubber component, stress relaxation and improvement in adhesion 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-terminated 1,2-polybutadiene, and styrene. Butadiene rubber, hydroxyl-terminated styrene-butadiene rubber, carboxyl group, hydroxyl group, carboxylated nitrile rubber, hydroxyl-terminated poly (oxypropylene), alkoxysilyl group-terminated poly (oxypropylene), poly (oxytetramethylene) glycol, polyolefin glycol and poly -Ε-caprolactone and the like.

The weight average molecular weight of the rubber component is preferably 2.0 × 10 ⁵ to 1.0 × 10 ⁶ . If 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 connecting material may decrease. is there. That is, according to the rubber component having the weight average molecular weight within the above range, a more excellent stress relaxation effect can be obtained while sufficiently suppressing the decrease in fluidity of the circuit connecting material.

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

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

If the content of the thermoplastic resin having a glass transition temperature of 25 ° C. or higher among the components (a) is less than 10% by mass, the film-forming property may be inferior. Fluidity may decrease. On the other hand, when it is in the above-mentioned range, it is possible to obtain more excellent film formability and connection reliability while sufficiently suppressing the decrease in the adhesive force and the fluidity of the circuit connection material.

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

In this 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 connecting material.

In this embodiment, as the component (b), a compound having a molecular weight exceeding 1000 (hereinafter sometimes referred to as “component (b-1)”) is mainly used, and a compound having a molecular weight of 1000 or less (hereinafter referred to as “component (b))”. The content of “(b-2) component” in some cases is 15% by mass or less based on the total amount of the circuit connecting material. By making the content of the component (b-1) 15% by mass or less, the above-described effects of the present invention can be remarkably obtained.

The content of the component (b-2) is preferably 15% by mass or less, and more preferably 12.5% by mass or less. In addition, the content of the component (b-2) may be 2.5% by mass or more, and may be 5% by mass or more.

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

The molecular weight of the component (b-1) is preferably 20000 or less, more preferably 15000 or less. 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. More preferably, it is 0.05 to 0.4, and further preferably 0.075 to 0.35.

Examples of the component (b-1) include oligomers such as epoxy (meth) acrylate oligomers, urethane (meth) acrylate oligomers, polyether (meth) acrylate oligomers, and polyester (meth) acrylate oligomers; trimethylolpropane tri (meth) Acrylate, polyethylene glycol di (meth) acrylate, polyalkylene glycol di (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, neopentyl glycol di (meth) acrylate, dipentaerythritol Hexa (meth) acrylate, isocyanuric acid modified bifunctional (meth) acrylate, isocyanuric acid modified trifunctional (meth) acrylate, bisphenol fluorenediglycol Epoxy (meth) acrylate obtained by adding (meth) acrylic acid to glycidyl group of diether, and (meth) acryloyloxy group added to compound obtained by adding ethylene glycol and / or propylene glycol to glycidyl group of bisphenol fluorenediglycidyl ether And polyfunctional (meth) acrylates such as introduced compounds. These compounds can be used individually by 1 type or in mixture of 2 or more types.

The component (b-2) includes pentaerythritol (meth) acrylate, 2-cyanoethyl (meth) acrylate, cyclohexyl (meth) acrylate, dicyclopentenyl (meth) acrylate, and dicyclopentenyloxyethyl (meth) acrylate. 2- (2-ethoxyethoxy) ethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-hexyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, hydroxy Propyl (meth) acrylate, isobornyl (meth) acrylate, isodecyl (meth) acrylate, isooctyl (meth) acrylate, n-lauryl (meth) acrylate, 2-methoxyethyl (meth) acrylate, 2 Phenoxyethyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, 2- (meth) acryloyloxyethyl phosphate, N, N-dimethylaminoethyl (meth) acrylate, N, N-dimethylaminopropyl (meth) acrylate , (Meth) acryloylmorpholine, and the like. These compounds can be used individually by 1 type or in mixture of 2 or more types.

The circuit connecting material preferably contains at least one compound having two or more (meth) acryloyl groups in the molecule as the component (b), and two or more in the molecule as the component (b-1). It is more preferable to contain at least one compound having a (meth) acryloyl group.

As the component (b), a compound having a (meth) acryloyl group is preferable, but as the component (b), a compound having a functional group that is polymerized by an active radical such as an allyl group, a maleimide group, and a vinyl group can also be used. Specific examples of such component (b) include N-vinylimidazole, N-vinylpyridine, N-vinylpyrrolidone, N-vinylformamide, N-vinylcaprolactam, 4,4′-vinylidenebis (N, N— Dimethylaniline), N-vinylacetamide, N, N-dimethylacrylamide, N-isopropylacrylamide, N, N-diethylacrylamide, methylolacrylamide, 4,4'-diphenylmethane bismaleimide, 3,3'-dimethyl-5,5 Examples include '-4,4'-diphenylmethane bismaleimide and 1,6-bismaleimide- (2,2,4-trimethyl) hexane.

Further, the circuit connecting material may contain a radical polymerizable compound having a phosphate ester structure as the component (b). Examples of the radical polymerizable compound having a phosphate ester structure include radical polymerizable compounds having a phosphate ester structure represented by the following formulas (2) to (4). By blending such a compound, the adhesive strength to the surface of an inorganic substance such as a metal is further improved, and a circuit connection material that is more effective for adhesion between circuit electrodes can be obtained.

In 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 represents an integer of 1 to 8. In the formula, R ^{5 s} , R ^{6 s} , w s, and x s may be the same or different.

In the formula (3), R ⁷ represents a (meth) acryloyloxy group, and y and z each independently represents an integer of 1 to 8. In the formula, R ^{7 s} , y s, and z s 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 represents an integer of 1 to 8.

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

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 connecting material.

Also, as a radical polymerizable compound having a phosphate ester structure, a compound obtained by reacting phosphoric anhydride and 2-hydroxyethyl (meth) acrylate can be used. Examples of such radically polymerizable compounds having a phosphate ester structure include mono (2-methacryloyloxyethyl) acid phosphate, di (2-methacryloyloxyethyl) acid phosphate, and the like. In addition, the compound which has a phosphate ester structure may be used individually by 1 type, or may mix and use 2 or more types.

The radical polymerizable compound having a phosphoric ester structure may be the component (b-1) or the component (b-2), and is preferably the component (b-2).

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

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

As the component (c), a peroxide having a one-minute half-life temperature of 90 to 175 ° C. and a molecular weight of 180 to 1000 is preferably used from the viewpoint of having stability, reactivity, and compatibility. it can. Here, “one-minute half-life temperature” refers to the temperature at which the half-life is 1 minute, and “half-life” refers to the time until the concentration of the compound decreases to half of the initial value.

Specific examples of the component (c) include 1,1,3,3-tetramethylbutylperoxyneodecanoate, di (4-t-butylcyclohexyl) peroxydicarbonate, di (2-ethylhexyl) peroxy Dicarbonate, cumylperoxyneodecanoate, 1,1,3,3-tetramethylbutylperoxyneodecanoate, dilauroyl peroxide, 1-cyclohexyl-1-methylethylperoxyneodecanoate, t -Hexylperoxyneodecanoate, t-butylperoxyneodecanoate, t-butylperoxypivalate, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, 2, 5-Dimethyl-2,5-di (2-ethylhexanoylperoxy) hexane, t-hexylperoxy -2-Ethylhexanoate, t-butylperoxy-2-ethylhexanoate, t-butylperoxyneoheptanoate, t-amylperoxy-2-ethylhexanoate, di-t-butylper Oxyhexahydroterephthalate, t-amylperoxy-3,5,5-trimethylhexanoate, 3-hydroxy-1,1-dimethylbutylperoxyneodecanoate, 1,1,3,3-tetramethylbutyl Peroxy-2-ethylhexanoate, t-amylperoxyneodecanoate, t-amylperoxy-2-ethylhexanoate, 3-methylbenzoyl peroxide, 4-methylbenzoyl peroxide, di (3 -Methylbenzoyl) peroxide, dibenzoyl peroxide, di (4-methylbenzoy) ) Peroxide, 2,2′-azobis-2,4-dimethylvaleronitrile, 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-cyclohexane) Carbonitrile), t-hexylperoxyisopropyl 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-hexylperoxybenzoate, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, t-butylperoxybenzoate, dibutylperoxytrimethyladipate, t-amylperoxynormal octoate, t- Examples include amyl peroxy isononanoate and t-amyl peroxybenzoate. In addition, (c) component may be used individually by 1 type, and may mix and use 2 or more types of compounds.

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.

Such compounds include, for example, Photoinitiation, Photopolymerization, and Photocuring, J. Biol. -P. Α-acetaminophenone 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 compound.

In order to suppress the corrosion of the circuit electrode of the circuit member, the amount of chlorine ion and organic acid contained in the component (c) is preferably 10000 mass ppm or less, more preferably 5000 mass ppm or less. . In addition, since corrosion of a circuit electrode will fully be suppressed if it is below this upper limit, the quantity of the chlorine ion and organic acid which are contained in (c) component may be 500 mass ppm or more.

The component (c) preferably has a mass retention of 20% by mass or more after being left open for 24 hours at room temperature (25 ° C.) and normal pressure. According to the component (c) having such a mass retention rate, the storage stability of the circuit connecting material is further improved. 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 and more preferably 1 to 20% by mass based on the total amount of the circuit connecting material. When the content of the component (c) is in the above range, the reaction rate for obtaining a sufficient adhesive force and a long pot life can be achieved at a higher level.

As the inorganic fine particles of 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. Moreover, (d) component can be used individually by 1 type or in mixture of 2 or more types.

The average particle size of the component (d) is preferably less than 1 μm, more preferably 0.1 to 0.5 μm. Here, the average particle diameter is the mode diameter in the major axis direction when present in the circuit connecting material. The average primary particle diameter of the component (d) is preferably 100 nm or less, 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 whose surface is modified with an organic group can be suitably used because of excellent dispersibility. Examples of the organic group include a dimethylsiloxane group and a diphenylsiloxane group.

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

The silane coupling agent represented by the formula (1) may be blended in the circuit connection material as a part of the component (b) as described above, and the circuit connection as a component other than the components (a) to (d). You may mix | blend with material.

When R ^{4 in the} formula (1) is a (meth) acryloyl group or a vinyl group, the 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 and more preferably 0.25 to 5% by mass based on the total amount of the circuit connecting material. When the content of the silane coupling agent is within the above range, generation of exfoliated bubbles at the interface between the circuit member and the connecting member can be more significantly suppressed, and a longer pot life can be secured. .

The circuit connection material of this embodiment may contain components other than those described above. For example, a stabilizer may be added to the circuit connection material for reasons such as controlling the curing rate and imparting storage stability. Stabilizers include quinone derivatives such as benzoquinone and hydroquinone; phenol derivatives such as 4-methoxyphenol and 4-t-butylcatechol; 2,2,6,6-tetramethylpiperidine-1-oxyl, 4-hydroxy- An aminoxyl derivative such as 2,2,6,6-tetramethylpiperidine-1-oxyl; a hindered amine derivative such as tetramethylpiperidyl methacrylate; and the like can be preferably used.

When the circuit connecting material contains a stabilizer, the content of the stabilizer is preferably 0.01 to 15% by mass, and 0.05 to 10% by mass based on the total amount of the circuit connecting material. It is more preferable. When the content of the stabilizer is less than 0.01% by mass, the effect of addition may not be sufficiently obtained. When the content exceeds 15% by mass, the polymerization reaction may be inhibited, and the low temperature rapid curability may be inferior.

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

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

When the circuit connecting 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 connecting material. .

In the circuit connection material of the present embodiment, conductive particles may be dispersed. Thereby, electroconductivity or anisotropic conductivity can be provided to a circuit connection material, and such a circuit connection material can be used suitably for the connection use etc. of the circuit members which have a circuit electrode. Moreover, the connection resistance between the connected circuit electrodes can be sufficiently reduced by connecting with such a circuit connection material.

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 this specification, “total amount of circuit connecting material” does not include conductive particles.

Examples of the conductive particles include metal particles made of metal such as Au, Ag, Pd, Ni, Cu, and solder, and carbon particles. In addition, the conductive particles may be particles made of a non-conductive material such as glass, ceramic, plastic, etc. as a core, and the core is coated with a conductive material such as the metal, metal particles, or carbon. Good.

Further, as the conductive particles, hot-melt metal particles are 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 electrodes increases, and the connection reliability between the circuit members is improved. There is a tendency.

The blending amount of the conductive particles is preferably 0.1 to 30% by volume, more preferably 0.1 to 10% by volume with respect to the total volume of the anisotropic conductive adhesive. If the blending amount of the conductive particles is less than 0.1% by volume, the conductivity tends to be inferior, and if it exceeds 30% by volume, a short circuit between the circuit electrodes tends to occur. In addition, the compounding quantity of electroconductive particle is determined based on the volume in 23 degreeC of each component of the circuit connection material before hardening. The volume of each component can be determined by converting mass to volume using specific gravity. Also, put an appropriate solvent (water, alcohol, etc.) that can wet the component well without dissolving or swelling the component whose volume is to be measured. It is also possible to obtain the volume increased by charging as the volume of the component.

The circuit connecting material of the present embodiment can be manufactured by mixing the above-described components without using a solvent. Moreover, it can also manufacture by mixing each above-mentioned component with the solvent which can melt | dissolve or disperse | distribute each said component.

The circuit connection material of this embodiment can be used in the form of a film. By using the shape of the film, the handleability of the circuit connecting material becomes extremely good.

Specifically, for example, after applying a solution prepared by adding a solvent or the like to a circuit connecting material on a peelable substrate such as a fluororesin film, a polyethylene terephthalate film or a release paper, the solvent is removed. By doing so, a film-like circuit connection material (hereinafter sometimes referred to as “film-like adhesive”) can be obtained. In addition, a solution prepared by adding a solvent or the like to a circuit connecting material as necessary is impregnated into a base material such as a nonwoven fabric and placed on a peelable base material, and the solvent is removed. An agent can be obtained. Moreover, electroconductive particle can be disperse | distributed to a film adhesive by mix | blending electroconductive particle at the time of mixing.

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

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

The film adhesive 1 may have a multilayer structure (not shown) composed of two or more layers. Further, conductive particles (not shown) may be dispersed in the film 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 adhesive containing the circuit connecting material and conductive particles.

Examples of the connection method of the adherend using the circuit connection material (for example, the film adhesive 1) of the present embodiment include a connection method using heating and pressurization together. In this method, the heating temperature is preferably 100 to 250 ° C. The pressure is not particularly limited as long as it does not damage the adherend, but it is generally preferably 0.1 to 10 MPa. These heating and pressurization are preferably performed in the range of 0.5 to 120 seconds. Further, according to the circuit connecting material, for example, adherends can be sufficiently bonded to each other by heating and pressurizing for 10 seconds under the conditions of a heating temperature of 150 to 200 ° C. and a pressure of 3 MPa.

The circuit connection material of the present embodiment can be suitably used as an adhesive for different types of adherends having different thermal expansion coefficients. Specifically, for example, as a circuit connection material represented by anisotropic conductive adhesive, silver paste, silver film, etc., or semiconductor element adhesion represented by CSP elastomer, CSP underfill material, LOC tape, etc. It can be used suitably as a material.

The circuit connection material of the present embodiment may be formed in a film shape on one surface of the film substrate.

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

In the adhesive film, since the film adhesive includes the circuit connecting material having the above-described specific configuration, even when the film base is wound in a reel shape so that the other surface of the film base is in contact with the film adhesive, Transfer of the film adhesive onto the other surface of the material is sufficiently suppressed.

When a similar wound body is produced with a conventional circuit connection material, the circuit connection material may ooze out from between the film base materials. In this adhesive film, the circuit adhesive has the above-mentioned specific configuration. Since the material is included, even when the film is wound in a reel shape, the bleeding of the film adhesive from between the film base materials is sufficiently suppressed. Therefore, the adhesive film can be suitably stored as a roll wound in a reel shape, and is further excellent in handleability.

Examples of the film substrate include polyethylene terephthalate, polycarbonate, and polypropylene.

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

The adhesive film may further include a protective film provided on the film adhesive. Since the protective film needs to be peeled off before the adherend is connected, it is desirable that the protective film has excellent peelability.

Hereinafter, an example in which circuit members having circuit electrodes formed on the main surface of a circuit board are connected to each other 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 form an anisotropic conductive adhesive is exemplified, but the circuit is also obtained by the same method when the conductive particles are not dispersed in the circuit connection material. Connection between members can be performed.

An anisotropic conductive adhesive is placed between the circuit electrodes facing each other on the circuit board and heated and pressed to perform electrical connection between the circuit electrodes facing each other and adhesion between the circuit boards. Can be connected.

Examples of the circuit board include a glass substrate; a flexible substrate made of an organic material such as polyimide, polyethylene terephthalate, and polycarbonate. Here, the effect of the present invention is particularly great when one of the circuit boards is a glass substrate and the other is a flexible board. Moreover, as a circuit board, the board | substrate which combined inorganic substance, such as glass / epoxy, and organic substance can also be used.

FIG. 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 facing each other, and the first circuit member 20 and the second circuit member 30 are disposed between the first circuit member 20 and the second circuit member 30. A connecting member 10 is provided to connect them.

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 21 a of the circuit board 21. Note that an insulating layer (not shown) may be formed on the main surface 21a of the circuit board 21 in some cases.

On the other hand, 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 31 a of the circuit board 31. In addition, an insulating layer (not shown) may be formed on the main surface 31a of the circuit board 31 according to circumstances.

The first and

second circuit members

20 and 30 are not particularly limited as long as electrodes that require electrical connection are formed. Specific examples include 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, etc. Used in combination as needed. As described above, in the present embodiment, materials such as printed wiring boards and polyimides, metals such as copper and aluminum, ITO (indium tin oxide), silicon nitride (SiN _x ), silicon dioxide (SiO ₂ ) are used. Circuit members having various surface states such as inorganic materials such as the above can be used.

The connecting member 10 contains an insulating substance 11 and conductive particles 7. The conductive particles 7 are disposed not only between the circuit electrode 22 and the circuit electrode 32 facing each other but also between the

main surfaces

21a and 31a. In this circuit connection structure, the

circuit electrodes

22 and 32 are electrically connected via the conductive particles 7. That is, the conductive particles 7 are in direct contact with both the

circuit electrodes

22 and 32.

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

In the circuit connection structure, as described above, the circuit electrode 22 and the circuit electrode 32 facing each other are electrically connected via the conductive particles 7. For this reason, the connection resistance between the

circuit electrodes

22 and 32 is sufficiently reduced. Therefore, the flow of current between the

circuit electrodes

22 and 32 can be made smooth, and the functions of the circuit can be fully exhibited. In addition, when the connection member 10 does not contain the conductive particles 7, the circuit electrode 22 and the circuit electrode 32 are in direct contact with each other to be electrically connected.

Since the connection member 10 is composed of the cured product of the circuit connection material and conductive particles, the adhesion strength of the connection member 10 to the

circuit member

20 or 30 is sufficiently high, and a reliability test (high temperature and high humidity) is performed. Even after the test), stable performance (good adhesive 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. First, the first circuit member 20 and the film adhesive 40 described above are prepared (see FIG. 3A). The film adhesive 40 is formed by forming a circuit connection material in which conductive particles are dispersed into a film shape, and includes the circuit connection material 5 and the conductive particles 7. Even when the conductive particles 7 are not dispersed in the film adhesive 40 (that is, when the film adhesive 40 is made of the circuit connecting material 5), the film adhesive is anisotropic as an insulating adhesive. It can be used for conductive bonding. At this time, the circuit connecting material is sometimes called NCP (Non-Conductive Paste). Moreover, when the electroconductive particle 7 is disperse | distributed to the circuit connection material 5, the material may be called ACP (Anisotropic Conductive Paste).

The thickness of the film adhesive 40 is preferably 6 to 50 μm. When the thickness of the film adhesive 40 is less than 6 μm, the circuit connecting material 5 tends to be insufficiently filled between the

circuit electrodes

22 and 32. On the other hand, when the thickness exceeds 50 μm, the circuit connecting material 5 between the

circuit electrodes

22 and 32 cannot be sufficiently removed, and it is difficult to ensure conduction between the

circuit electrodes

22 and 32.

Next, the film adhesive 40 is placed on the surface of the first circuit member 20 on which the circuit electrode 22 is formed. When the film adhesive 40 is attached on a support (not shown), the first circuit member 20 is arranged such that the film adhesive 40 side faces the first circuit member 20. Put it on top. At this time, the film adhesive 40 is in a film form and is easy to handle. For this reason, the film adhesive 40 can be easily interposed between the first circuit member 20 and the second circuit member 30, and the connection between the first circuit member 20 and the second circuit member 30 is possible. Work can be done easily.

Then, the film adhesive 40 is pressurized in the directions of arrows A and B in FIG. 3A to temporarily connect the film adhesive 40 to the first circuit member 20 (see FIG. 3B). At this time, you may pressurize, heating. However, the heating temperature is set to a temperature lower than the temperature at which the film adhesive 40 (the circuit connecting material 5 constituting the film adhesive 40) is not cured.

Subsequently, as shown in FIG. 3 (c), the second circuit member 30 is placed on the film adhesive 40 so that the second circuit electrode 32 faces the first circuit member 20. In addition, when the film adhesive 40 has adhered on the support body (for example, the above-mentioned film-form base material (not shown)), after peeling a support body, the 2nd circuit member 30 is made into a film form. Place on adhesive 40. At this time, the first and second circuit electrodes 22 and 23 are aligned so that they face each other, and then the second circuit member 30 is temporarily fixed by heating and pressing from above the second circuit member 30. be able to. By doing so, it is possible to suppress the positional deviation of the electrodes 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 adhesive 40 is not cured, and the time from alignment to completion of temporary fixing is preferably 5 seconds or less for shortening the throughput. .

Then, the film adhesive 40 is heated through the first and

second circuit members

20 and 30 in the directions of arrows A and B in FIG. The heating temperature at this time is set to a temperature at which the polymerization reaction can be started. In this way, the film-like adhesive 40 is cured to perform the main connection, and a circuit connection structure as shown in FIG. 2 is obtained.

Here, as described above, the connection conditions are preferably a heating temperature of 100 to 250 ° C., a pressure of 0.1 to 10 MPa, and a connection time of 0.5 seconds to 120 seconds. These conditions are appropriately selected depending on the intended use, circuit connection material, and circuit member, and may be post-cured as necessary.

By manufacturing the circuit connection structure as described above, in the obtained circuit connection structure, the conductive particles 7 can be brought into contact with both of the

circuit electrodes

22 and 32 facing each other. The connection resistance between them can be sufficiently reduced.

Further, by heating the film adhesive 40, the circuit connecting material 5 is cured to become the insulating substance 11 in a state where the distance between the circuit electrode 22 and the circuit electrode 32 is sufficiently small, and the first circuit member 20 is cured. And the second circuit member 30 are firmly connected via the connection member 10. That is, in the obtained circuit connection structure, since the connection member 10 includes the insulating substance 11 made of the circuit connection material described above, the bonding strength of the connection member 10 to the

circuit member

20 or 30 is sufficiently high, The connection resistance between the electrically connected circuit electrodes can be sufficiently reduced. In addition, even when left in a high-temperature and high-humidity environment for a long period of time, the generation of peeling bubbles at the interface between the

circuit members

20 and 30 and the connection member 10 can be sufficiently suppressed, and the adhesive strength is reduced In addition, an increase in connection resistance can be sufficiently suppressed.

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

For example, the present invention provides a circuit connection for electrically connecting two opposing circuit members of a composition containing the thermoplastic resin, the radical polymerizable compound, the radical polymerization initiator, and the inorganic fine particles. It can be said that it is applied as a material. Further, the present invention provides a circuit connection for electrically connecting two opposing circuit members of the composition containing the thermoplastic resin, the radical polymerizable compound, the radical polymerization initiator, and the inorganic fine particles. It can also be referred to as an application for the production of materials.

In these applications, the content of the radical polymerizable compound is 40% by mass or more based on the total amount of the composition, and the content of a compound having a molecular weight of 1000 or less of the radical polymerizable compound is 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). contains.

According to these applications, even if the circuit member is a radical polymerization type, even when the circuit member is left in a high-temperature and high-humidity environment after connection, the generation of exfoliated bubbles at the interface with the circuit member can be sufficiently suppressed and sufficient connection reliability can be achieved. Thus, the above-described circuit connection material capable of maintaining the properties can be obtained.

Hereinafter, the present invention will be described more specifically with reference to 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 condenser, a thermometer, and a 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 temperature of this solution was raised 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 was dissolved in 125 parts by mass of methyl ethyl ketone. The solution was added dropwise over 1 hour.

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

The weight average molecular weight in terms of polystyrene of the obtained polyurethane resin was 320,000 as a result of measurement by GPC. The GPC analysis conditions are shown in Table 1 below.

(Production Example 2: Synthesis of radically polymerizable compound)
In a 2 liter four-necked flask equipped with a thermometer, stirrer, inert gas inlet and reflux condenser, polycarbonate diol (manufactured by Aldrich, number average molecular weight 2000) 4000 parts by mass, 2-hydroxyethyl acrylate 238 parts by mass Then, 0.49 parts by mass of hydroquinone monomethyl ether and 4.9 parts by mass of a tin catalyst were charged and heated to 70 ° C., and 666 parts by mass of IPDI (isophorone diisocyanate) was uniformly dropped over 3 hours to be reacted. The reaction was continued for 15 hours after completion of the dropwise addition, and the reaction was terminated when NCO% (the amount of isocyanate group relative to the urethane group) was 0.2% or less, to obtain urethane acrylate. As a result of analysis by GPC, the weight average molecular weight of the obtained urethane acrylate was 8,500. The GPC analysis was performed under the conditions shown in Table 1.

(Production Example 3: Production of conductive particles)
A layer made of nickel having a thickness of 0.2 μm was provided on the surface of the polystyrene particles, and a layer made of gold was provided on the surface of the layer made of nickel so as 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)
As the thermoplastic resin of component (a), a phenoxy resin (PKHC, trade name of Union Carbide, weight average molecular weight 45000, represented as “PKHC” in the table) 40 g in 40 g of solid content dissolved in 60 g of methyl ethyl ketone. % Solution and a polyurethane resin (represented as “PU” in the table) obtained in Production Example 1 having a solid content concentration of 30 mass% were used.

In addition, as the radically polymerizable compound of component (b), urethane acrylate obtained in Production Example 2 (represented as “UA” in the table), cyclohexyl acrylate (manufactured by Toagosei Co., Ltd., represented as “CHA” in the table). ), 2- (meth) acryloyloxyethyl phosphate (light ester P-2M, trade name, manufactured by Kyoeisha Co., Ltd., indicated as “P-2M” in the table), and 3-methacryloxypropyltri Methoxysilane (KBM503, trade name manufactured by Shin-Etsu Chemical Co., Ltd., silane coupling agent, represented as “KBM” in the table) was used.

Further, as the radical polymerization initiator of component (c), t-hexyl peroxy-2-ethylhexanoate (Perhexyl O, trade name, manufactured by Yushi Co., Ltd., represented as “peroxide” in the table) is used. It was.

In addition, as inorganic fine particles of component (d), 10 g of R711 (product name manufactured by Nippon Aerosil Co., Ltd., represented as “R711” in the table) is dispersed in a mixed solvent of 45 g of toluene and 45 g of ethyl acetate. Used as a solution.

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

The content of the radically polymerizable compound in the film-like adhesives of the examples and comparative examples, the content of the radically polymerizable compound (component (b-1)) having a molecular weight exceeding 1000, and the radically polymerizable compound having a molecular weight of 1000 or less ( The content of the component (b-2) and the content of the inorganic fine particles were as shown in Table 3 calculated from the respective compounding amounts (both circuit connection materials (conductive particles of the film adhesive) %) Based on the total amount of components other than The silane coupling agent 3-methacryloxypropyltrimethoxysilane is included in the component (b-2).

(Examples 6 to 10 and Comparative Examples 6 to 10)
Using the film adhesives of Examples 1 to 5 and Comparative Examples 1 to 5, connection structures of Examples 6 to 10 and Comparative Examples 6 to 10 were produced.

Specifically, the film-like adhesive is a glass substrate (thickness 1.1 mm) on which a thin film of indium oxide (ITO) having a thickness of 0.2 μm is formed under conditions of 1 MPa and 2 seconds at a temperature of 70 ° C. ) Transcription. Next, this glass substrate and a flexible circuit board (FPC board) in which 500 copper circuits having a line width of 75 μm, a pitch of 150 μm, and a thickness of 18 μm are wired on polyimide with an epoxy resin adhesive are used as a film adhesive Were placed so as to face each other, and heated and pressurized at 3 MPa at a temperature of 160 ° C. for 10 seconds using a thermocompression bonding apparatus (heating method: constant heat type, manufactured by Toray Engineering Co., Ltd.). Thereby, the connection body (circuit connection structure) by which the FPC board and the glass substrate (ITO board | substrate) were connected by the cured | curing material (connection member) of the film adhesive over 2 mm in width was obtained.

(Evaluation of circuit connection structure 1: Evaluation of initial connection resistance)
About the circuit connection structure obtained by the Example and the comparative example, the resistance value (connection resistance) between adjacent circuits was measured with the multimeter, respectively. The average of 37 resistances between adjacent circuits was used as the evaluation result of the initial connection resistance. The evaluation results are shown in Table 4.

(Evaluation of circuit connection structure 2: Evaluation of initial adhesive strength)
For the circuit connection structures obtained in the examples and comparative examples, the adhesive strength between the connection member and the FPC board was measured by a 90-degree peeling method according to JIS-Z0237, and the measured value was the initial adhesion. The result of the evaluation of force. As an adhesive force measuring apparatus, Tensilon UTM-4 (peeling speed 50 mm / min, 25 ° C.) manufactured by Toyo Baldwin Co., Ltd. was used. Table 4 shows the evaluation results.

(Circuit connection structure evaluation 3: characteristic evaluation after high temperature and high humidity test)
The circuit connection structures obtained in Examples and Comparative Examples were held for 250 hours under the conditions of 85 ° C. and 85% RH to obtain measurement samples. About the obtained sample, connection resistance and adhesive strength were evaluated by the same method as said evaluation 1 and 2. The evaluation results are shown in Table 4.

Moreover, about the obtained sample, the presence or absence of the peeling in the interface of a connection member and an FPC board and the interface of a connection member and a glass substrate was investigated using the microscope (brand name: ECLIPSE L200, Nikon Corporation make). . The case where there was no interfacial delamination was evaluated as “A”, the case where there was slight interfacial delamination as “B”, and the case where interfacial delamination occurred to some extent in practical use was evaluated as “C”. The evaluation results are shown in Table 4.

As is apparent from the results shown in Table 4, the circuit connection structures obtained in Examples 6 to 10 showed a resistance value of 3Ω or less both in the initial stage and after the high temperature and high humidity test. No peeling bubbles or the like were generated at the interface with the circuit member.

On the other hand, the circuit connection structure of Comparative Example 6 obtained using the film-like adhesive of Comparative Example 1 containing no inorganic fine particles, and 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 Comparative Example 7 obtained using the above, after the high-temperature and high-humidity test, the connection resistance was remarkably increased, the adhesive force was decreased, and peeling was observed at the interface between the connection member and the circuit member. Further, the circuit connection 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 Comparative Example not containing a silane coupling agent In the circuit connection structure of Comparative Example 10 obtained by using the film-like adhesive of No. 5, peeling occurred remarkably at the interface between the connection member and the circuit member after the high temperature and high humidity test. Furthermore, in the circuit connection structure of Comparative Example 9 obtained by using the film-like adhesive of Comparative Example 4 which does not contain inorganic fine particles and the content of the component (b-2) exceeds 15% by mass, the connection resistance is low. As a result, the adhesive force decreased, and the interface between the connecting member and the circuit member was remarkably peeled off.

(Examples 11 to 15 and Comparative Examples 11 to 15)
Each of the coating solutions used in the production of the film adhesives of Examples 1 to 5 and Comparative Examples 1 to 5 was applied to a polyethylene terephthalate (PET) film having a thickness of 50 μm, and the coating solution was 70 ° C. for 10 minutes. Hot air drying was performed to form a film adhesive having a thickness of 16 μm on the PET film, and an adhesive film including the PET film and the film adhesive was obtained.

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

(Evaluation of rolls of adhesive film)
A load of 75 g was fixed to the front end of the wound body of the obtained adhesive film, and the load was left hanging at 30 ° C. for 6 hours. The wound body after standing was observed, and it was confirmed whether or not the film adhesive exuded from between the PET films. Moreover, the adhesive film was pulled out from the wound body after standing, and the presence or absence of transfer of the film adhesive to the PET film back surface was confirmed. “A” indicates that no exudation or transfer was observed, “B” indicates that no exudation was observed but exudation was observed, and “C” indicates that no exudation or transfer was observed. " The evaluation results are shown in Table 5.

As is apparent from the results shown in Table 5, the adhesive films obtained in Examples 11 to 15 did not show any oozing out of the film adhesive even after being left for 6 hours under a load of 75 g at 30 ° C., and the back surface of the PET film No transcription was seen. On the other hand, in Comparative Examples 11 to 13, bleeding of the film-like base material from between the PET films was observed in the wound body. In Comparative Examples 11 and 14, not only the seepage but also the transfer of the film adhesive onto the back surface of the PET film was observed.

DESCRIPTION OF SYMBOLS 1 ... Film adhesive, 5 ... Circuit connection material, 7 ... Conductive particle, 10 ... Connection member, 11 ... Insulating substance, 20 ... First circuit member, 21 ... Circuit board (1st 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 electrode) Circuit electrode), 40 ... film adhesive.

Claims

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,
The content of the radical polymerizable compound is 40% by mass or more based on the total amount of the circuit connecting material,
The content of a compound having a molecular weight of 1000 or less among the radical polymerizable compounds is 15% by mass or less based on the total amount of the circuit connecting material,
The content of the inorganic fine particles is 5 to 30% by mass based on the total amount of the circuit connecting material,
A circuit connecting material containing at least a compound represented by the following formula (1).

[Wherein R 1 , R 2 and R 3 are each independently 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. At least one of R 1 , R 2 and R 3 is an alkoxy group having 1 to 5 carbon atoms, and R 4 is a (meth) acryloyl group, a vinyl group, an isocyanate group, an imidazole group, a mercapto group, An amino group, a methylamino group, a dimethylamino group, a benzylamino group, a phenylamino group, a cyclohexylamino group, a morpholino group, a piperazino group, a ureido group, or a glycidyl group, and n represents an integer of 1 to 10. ]
The circuit connection material according to claim 1, wherein the thermoplastic resin contains at least one resin having a glass transition temperature of 25 ° C or higher.
The circuit connection material according to claim 1 or 2, wherein an average particle size of the inorganic fine particles is less than 1 µm.
The circuit connection material according to any one of claims 1 to 3, wherein conductive particles are dispersed.
The circuit connection material according to any one of claims 1 to 4, wherein the shape is a film shape.
The circuit connection material according to any one of claims 1 to 5, wherein at least one of the two circuit members is a glass substrate.
The circuit connection material according to any one of claims 1 to 6, wherein at least one of the two circuit members is a flexible substrate.
An anisotropic conductive adhesive comprising the circuit connection material according to any one of claims 1 to 7 and conductive particles dispersed in the circuit connection material.
A pair of circuit members disposed opposite to each other;
A cured product of the circuit connection material according to any one of claims 1 to 7, wherein the circuit electrodes interposed between the pair of circuit members are electrically connected to each other. A connecting member that connects the circuit members;
A circuit connection structure comprising:
An adhesive film comprising: a film base material; and a film adhesive containing the circuit connecting material according to any one of claims 1 to 7 provided on one surface of the film base material.
Application of a composition containing a thermoplastic resin, a radical polymerizable compound, a radical polymerization initiator and inorganic fine particles as a circuit connection material for electrically connecting two opposing circuit members,
The content of the radical polymerizable compound is 40% by mass or more based on the total amount of the composition,
The content of a compound having a molecular weight of 1000 or less among the radical polymerizable compounds 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,
Application wherein the composition contains at least a compound represented by the following formula (1).

[Wherein R 1 , R 2 and R 3 are each independently 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. At least one of R 1 , R 2 and R 3 is an alkoxy group having 1 to 5 carbon atoms, and R 4 is a (meth) acryloyl group, a vinyl group, an isocyanate group, an imidazole group, a mercapto group, An amino group, a methylamino group, a dimethylamino group, a benzylamino group, a phenylamino group, a cyclohexylamino group, a morpholino group, a piperazino group, a ureido group, or a glycidyl group, and n represents an integer of 1 to 10. ]
The application according to claim 11, wherein the thermoplastic resin contains at least one resin having a glass transition temperature of 25 ° C or higher.
The application according to claim 11 or 12, wherein an average particle size of the inorganic fine particles is less than 1 µm.
The application according to any one of claims 11 to 13, wherein conductive particles are dispersed in the circuit connecting material.
The application according to any one of claims 11 to 14, wherein a shape of the circuit connecting material is a film.
The application according to any one of claims 11 to 15, wherein at least one of the two circuit members is a glass substrate.
The application according to any one of claims 11 to 16, wherein at least one of the two circuit members is a flexible substrate.
An application of a composition containing a thermoplastic resin, a radical polymerizable compound, a radical polymerization initiator and inorganic fine particles for producing a circuit connecting material for electrically connecting two opposing circuit members. ,
The content of the radical polymerizable compound is 40% by mass or more based on the total amount of the composition,
The content of a compound having a molecular weight of 1000 or less among the radical polymerizable compounds 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,
Application wherein the composition contains at least a compound represented by the following formula (1).

[Wherein R 1 , R 2 and R 3 are each independently 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. At least one of R 1 , R 2 and R 3 is an alkoxy group having 1 to 5 carbon atoms, and R 4 is a (meth) acryloyl group, a vinyl group, an isocyanate group, an imidazole group, a mercapto group, An amino group, a methylamino group, a dimethylamino group, a benzylamino group, a phenylamino group, a cyclohexylamino group, a morpholino group, a piperazino group, a ureido group, or a glycidyl group, and n represents an integer of 1 to 10. ]
The application according to claim 18, wherein the thermoplastic resin contains at least one resin having a glass transition temperature of 25 ° C or higher.
The application according to claim 18 or 19, wherein the inorganic fine particles have an average particle size of less than 1 µm.
The application according to any one of claims 18 to 20, wherein conductive particles are dispersed in the circuit connecting material.
The application according to any one of claims 18 to 21, wherein a shape of the circuit connecting material is a film.
The application according to any one of claims 18 to 22, wherein at least one of the two circuit members is a glass substrate.
The application according to any one of claims 21 to 23, wherein at least one of the two circuit members is a flexible substrate.