JP2006022231A - Anisotropically conductive adhesive and anisotropically conductive adhesive film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an anisotropically conductive adhesive capable of the connection at a low temperature in a short time and excellent in reliability of the connection. <P>SOLUTION: The adhesive contains as the essential components (a) a radically polymerizable resin, (b) an adhesiveness provider, (c) an organic peroxide, and (d) conductive particles. The adhesiveness provider (b) is so constituted as to contain a compound having a vinyl group and a nitrile group or a compound having a vinyl group and an alkoxy group. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an anisotropic conductive adhesive and an anisotropic conductive adhesive film.

  In recent years, the need for fine circuit connection such as connection between a liquid crystal display (LCD) and a tape carrier package (TCP) and connection between a TCP and a printed circuit board (PCB) has increased. As the connection method, a method using a film-like anisotropic conductive adhesive in which conductive particles are dispersed in an adhesive resin is used.

  In this method, a film of anisotropic conductive adhesive is sandwiched between members to be connected and heated and pressed to maintain electrical insulation between adjacent terminals in the plane direction, while electrically conducting between upper and lower terminals. It is.

  The adhesive resin in the anisotropic conductive adhesive is classified into a thermoplastic resin type and a thermosetting resin type. Recently, among these, a thermosetting resin type that is more reliable than a thermoplastic resin type is being widely used.

  Among the thermosetting resin type anisotropic conductive adhesives that are currently mainstream, epoxy resin-based adhesive resins that are excellent in the balance between storage stability and curability are widely used as adhesive resins.

  However, in practice, the thermosetting resin type is required to be heated and cured at a temperature of 170 ° C. to 200 ° C. for about 30 seconds in order to achieve both storage stability and resin curability. It is said. For this reason, it was difficult to cure the thermosetting resin in a practical connection time at a temperature of 150 ° C. or less, for example.

On the other hand, as the curing agent for the adhesive resin, for example, a latent curing agent such as BF ₃ amine complex, dicyandiamide, organic acid hydrazide, microencapsulated imidazole compound, etc. is used. Conductive adhesives have been proposed. However, those with excellent storage stability require a long time or high temperature for curing, and those that can be cured at a low temperature in a short time tend to be inferior in storage stability. The conductive adhesive had room for improvement.

  In addition, the LCD module has a larger screen, higher accuracy, and a narrower frame, and accordingly, connection pitches and connection widths have been rapidly reduced. Therefore, for example, in the connection between the LCD and the TCP, the connection portion is displaced due to the elongation of the TCP due to heating at the time of connection, or because the connection portion is thin, the members inside the LCD are thermally at the temperature at the time of connection. I was affected.

  Therefore, it was considered to solve these problems by connecting at a lower temperature, but when connecting at a low temperature using an anisotropic conductive adhesive based on epoxy resin, the connection time is required to cure the resin. It was necessary to lengthen the length, and there was nothing that could be applied practically.

  Therefore, as an anisotropic conductive adhesive that enables low-temperature connection, a technique has been proposed in which conductive particles are dispersed in an adhesive resin containing a cationically polymerizable substance and a sulfonium salt (Patent Document 1). However, the anisotropic conductive adhesive described in Patent Document 1 has room for improvement in terms of the storage stability of the adhesive resin and the corrosion of the connected circuit terminals, and has not yet been put into practical use.

JP-A-7-90237

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an anisotropic conductive adhesive that can be bonded at a low temperature in a short time and has excellent connection reliability.

According to the present invention,
(A) radical polymerizable resin,
(B) an adhesion-imparting agent,
(C) an organic peroxide, and (d) conductive particles,
Is provided as an essential component, and the (b) adhesion-imparting agent includes a compound having a vinyl group and a nitrile group.

  An anisotropic conductive adhesive according to the present invention comprises (a) a radical polymerizable resin and (d) conductive particles, and (b) an adhesion imparting agent having a vinyl group and a nitrile group in the molecule. Including. For this reason, even when bonded under low-temperature and short-time curing conditions, sufficient adhesion to the material to be bonded can be ensured. For this reason, it can be set as the structure excellent in low-temperature short-time curability and connection reliability.

  In the anisotropic conductive adhesive of the present invention, the compound having a vinyl group and a nitrile group may be a radical polymerizable macromonomer. By carrying out like this, the adhesiveness with respect to a to-be-adhered material can further be improved. In the anisotropic conductive adhesive of the present invention, the compound having a vinyl group and a nitrile group may be a macromonomer of a (meth) acryl compound.

  In the anisotropic conductive adhesive of the present invention, the (b) adhesion imparting agent may further contain a compound having a vinyl group and an alkoxy group. By doing so, it is possible to sufficiently secure the adhesion to the material to be bonded even when bonded under low temperature and short time curing conditions. For this reason, it can be set as the structure excellent in low-temperature short-time curability and connection reliability.

  The anisotropic conductive adhesive of the present invention may further include a silane coupling agent having a glycidyl group or a silane coupling agent having a mercapto group. By carrying out like this, the adhesiveness with respect to the metal in a to-be-adhered material can be improved further. For this reason, low-temperature short-time curability and connection reliability can be further improved.

According to the present invention,
(A) radical polymerizable resin,
(B) an adhesion-imparting agent,
(C) an organic peroxide,
(D) Conductive particles and a silane coupling agent having a glycidyl group or a silane coupling agent having a mercapto group as essential components, and (b) the adhesion-imparting agent is a compound having a vinyl group and an alkoxy group An anisotropic conductive adhesive is provided, characterized in that

  An anisotropic conductive adhesive according to the present invention comprises (a) a radical polymerizable resin and (d) conductive particles, and (b) an adhesion imparting agent having a vinyl group and an alkoxy group in the molecule. Including. Moreover, the silane coupling agent which has a glycidyl group, or the silane coupling agent which has a mercapto group is included. For this reason, even when bonded under low-temperature and short-time curing conditions, sufficient adhesion to the material to be bonded can be ensured. Therefore, it can be set as the structure excellent in low-temperature short-time curability and connection reliability.

  In the anisotropic conductive adhesive of the present invention, the content of the compound having a vinyl group and an alkoxy group can be 1% by weight or more and 10% by weight or less of the whole anisotropic conductive adhesive. By doing so, it is possible to further improve the low-temperature short-time curability and connection reliability.

  In the anisotropic conductive adhesive of the present invention, the alkoxy group may be a methoxy group or an ethoxy group. By carrying out like this, the adhesiveness with respect to a to-be-adhered material can further be improved. In the anisotropic conductive adhesive according to the present invention, the compound having a vinyl group and an alkoxy group may be vinyl alkoxysilane.

  The anisotropic conductive adhesive of the present invention may further include (e) a thermoplastic elastomer. By doing so, the adhesion to the adherend material can be further improved. In the anisotropic conductive adhesive according to the present invention, the content of the thermoplastic elastomer (e) can be 20% by weight or more and 80% by weight or less of the whole anisotropic conductive adhesive.

  In the anisotropic conductive adhesive of the present invention, the (a) radical polymerizable resin may be an epoxy acrylate resin, a (meth) acryloylated phenol novolak resin having a phenolic hydroxyl group, and a urethane acrylate resin. Adhesiveness with a to-be-adhered material can be improved by setting it as the structure containing these resin and (b) adhesiveness imparting agent. For this reason, connection reliability can be improved.

  In the anisotropic conductive adhesive of the present invention, the (meth) acrylic resin is selected from the group consisting of an epoxy acrylate resin, a (meth) acryloylated phenol novolak resin having a phenolic hydroxyl group, and a urethane acrylate resin. Alternatively, two or more resins may be included. By doing so, the low-temperature short-time curability can be further improved.

  In the anisotropic conductive adhesive of the present invention, (f) a reactive monomer may be included, and the (f) reactive monomer may be composed of a (meth) acrylic acid derivative. By doing so, the heat resistance of the anisotropic conductive adhesive can be improved.

  In the anisotropic conductive adhesive of the present invention, the reactive monomer may include a compound having a cycloalkyl group. By doing so, the heat resistance of the anisotropic conductive adhesive can be further improved.

  According to the present invention, there is provided an anisotropic conductive adhesive film, wherein the anisotropic conductive adhesive is formed into a film. Since the anisotropic conductive adhesive according to the present invention is formed into a film shape, it has a configuration excellent in adhesion to a material to be bonded even under low temperature and short time curing conditions.

  According to the present invention, (a) a radical polymerizable resin, (b) an adhesion-imparting agent, (c) an organic peroxide, and (d) conductive particles are included as essential components; By including a compound having a vinyl group and a nitrile group or a compound having a vinyl group and an alkoxy group, the adhesive can be bonded at a low temperature in a short time, and an anisotropic conductive adhesive with excellent connection reliability has been realized. Is done.

  Hereinafter, the anisotropic conductive adhesive of this invention and the anisotropic conductive adhesive film formed by shape | molding this to a film form are demonstrated. In addition, a display device and an electronic apparatus using the anisotropic conductive adhesive film of the present invention will be described.

The anisotropic conductive adhesive of the present invention is
(A) radical polymerizable resin,
(B) an adhesion-imparting agent,
(C) an organic peroxide, and (d) conductive particles,
It is comprised with the resin composition which contains as an essential component.

  The anisotropic conductive adhesive of this invention is comprised with the resin composition containing the (a) radical polymerizable resin which is curable resin. Thereby, the heat resistance and moisture resistance of the cured resin can be improved. In addition, connectivity under harsh environments and long-term connection reliability can be improved.

  In addition, by using a radically polymerizable resin among the curable resins, it can be cured at a particularly low temperature in a short time, and the storability can be achieved.

(A) As the radical polymerizable resin, for example, a resin having an ethylene bond can be used. As such a resin, for example, a (meth) acryloylated phenol novolak resin having a phenolic hydroxyl group;
Vinyl ester resin;
Acrylates such as epoxy acrylate resins and urethane acrylate resins;
Phthalate resins such as diacryl phthalate resin and diallyl phthalate resin;
Unsaturated polyester resin;
Maleimide resin;
Etc. These resins may be used alone or in combination of two or more.

  Further, the (a) radical polymerizable resin may be a resin having a (meth) acryloyl group. Specifically, for example, it is preferable to include one or more resins selected from the group consisting of epoxy acrylate resins, (meth) acryloylated phenol novolak resins having a phenolic hydroxyl group, and urethane acrylate resins. Thereby, both short-time curability at low temperature and storage stability can be achieved. Moreover, while being able to improve the heat resistance and moisture resistance of hardened | cured material, the adhesive force with respect to a to-be-adhered body can be improved. For this reason, high long-term connection reliability can be realized.

  The content of the (a) radical polymerizable resin is not particularly limited, but may be 20% by weight or more, preferably 30% by weight, based on the total anisotropic conductive adhesive. By doing so, the heat resistance and moisture resistance of the anisotropic conductive adhesive can be improved. In addition, the content of the (a) radical polymerizable resin can be, for example, 80% by weight or less, preferably 60% by weight. By carrying out like this, the elastic modulus of hardened | cured material can suppress an excessive raise and can improve connection reliability reliably.

  In addition, a polymerization inhibitor such as quinones, polyhydric phenols, and phenols may be added in advance to the anisotropic conductive adhesive. If it carries out like this, the preservability of (a) radically polymerizable resin can fully be ensured. Further, (a) Trimethylolpropane triacrylate (TMPTA), pentaerythritol diacrylate, tetraethylene glycol diacrylate, pentaerythritol tetra, in order to improve the curability of the radical polymerizable resin, the fluidity during heating, or the workability. Acrylates such as acrylate and various monomers such as styrene may be blended in the anisotropic conductive adhesive. Various monomers may be diluted with a general reactive diluent and blended in the anisotropic conductive adhesive.

  Next, (b) an adhesion-imparting agent is a compound having (a) a functional group having reactivity with a radical polymerizable resin and a functional group having affinity for an adherend. By adding such a compound, adhesion to the adherend can be improved. For this reason, connection reliability can be improved.

  Moreover, when TCP and PCB for LCD are connected using the anisotropic conductive adhesive which concerns on this invention, (b) adhesion imparting agent is (a) radical polymerization resin and to-be-adhered body (TCP, PCB, etc.) ) Has an affinity for the metal part and exhibits an action of coupling them, so that the connection reliability is particularly excellent.

(B) Adhesion imparting agent is
(I) a compound having a vinyl group and a nitrile group (ii) a compound having a vinyl group and an alkoxy group,
including. Any of the adhesiveness imparting agents (i) and (ii) may be used alone or in combination. Moreover, as an adhesiveness imparting agent of the above (i) and (ii), one compound may be included, or a plurality of compounds may be included.

  Since the anisotropic conductive adhesive of the present invention contains the above-mentioned (i) or (ii) adhesion-imparting agent, when the (a) radical polymerization resin contains a (meth) acryloyl group, the adhesion is further increased. Will improve. The reason for improving adhesion by using these compounds is not always clear, but nitrile groups and alkoxy groups have polarity, so they interact with metals and organic substances existing on the surface of the material to be bonded, or form chemical bonds. And that the double bond portion derived from the vinyl group is incorporated into the cured matrix of the (a) radical polymerization resin having a (meth) acryloyl group. And by these synergistic effects, the anisotropic conductive adhesive according to the present invention has high adhesion to the adherend interface, and the cohesive force of the cured product is increased, so that excellent adhesiveness is exhibited. It is done.

Hereinafter, the above compounds (i) and (ii) will be described in order.
(I) As the compound having a vinyl group and a nitrile group, for example, a (meth) acrylic compound having a nitrile atom can be used. Further, (i) a compound having a vinyl group and a nitrile group can be a radical polymerizable macromonomer.

  (I) The compound having a vinyl group and a nitrile group may be a macromonomer of a (meth) acrylic compound. Examples of the macromonomer of the (meth) acrylic compound include a copolymer of a compound having a methacryloyl group terminal and -acrylonitrile. Specific examples include a methacryloyl group-terminated styrene-acrylonitrile copolymer, a methacryloyl group-terminated butyl acrylate-acrylonitrile copolymer, and an acryloyl group-terminated methyl methacrylate-acrylonitrile copolymer. By using these compounds, adhesion to the adherend interface, particularly adhesion to engineering plastics such as metal and polyimide can be improved.

  Among these, it is preferable to use an acryloyl group-terminated styrene-acrylonitrile copolymer. By using the acryloyl group-terminated styrene-acrylonitrile copolymer, the adhesion to the adherend interface can be further improved.

  (I) The content of the compound having a vinyl group and a nitrile group is not particularly limited, but can be 0.1% by weight or more, preferably 0.5% by weight or more of the whole anisotropically conductive adhesive. . By doing so, the adhesion with the adherend interface can be reliably improved. Further, (i) the content of the compound having a vinyl group and a nitrile group can be, for example, 10% by weight or less, preferably 8% by weight or less of the whole anisotropically conductive adhesive. By carrying out like this, corrosion of the metal part of the adherend surface can be suppressed, and sufficient insulation can be secured.

  In addition, (ii) the compound having a vinyl group and an alkoxy group can be, for example, vinyl alkoxysilane. Specific examples of the vinylalkoxysilane include vinyltrimethoxysilane and vinyltriethoxysilane.

  Moreover, (ii) In the compound having a vinyl group and an alkoxy group, the alkoxy group can be, for example, a methoxy group or an ethoxy group. Specific examples of the vinyl alkoxysilane in which the alkoxy group is a methoxy group or an ethoxy group include, for example, vinyl methoxy silane or vinyl ethoxy silane, specifically, for example, 3-methacryloxypropylmethyldimethoxy silane, Roxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropylmethyldimethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-acryloxypropylmethyldi Examples include ethoxysilane, and 3-acryloxypropyltriethoxysilane.

  Further, in the anisotropic conductive adhesive according to the present invention, (a) the radical polymerizable resin includes a (meth) acrylic resin, and (b) the adhesion imparting agent is a vinyl alkoxy whose alkoxy group is a methoxy group or an ethoxy group. It can be set as the structure containing a silane. By carrying out like this, the adhesiveness to a to-be-adhered body can further be improved.

  (Ii) The content of the compound having a vinyl group and an alkoxy group can be, for example, 1% by weight or more, preferably 3% by weight or more of the entire anisotropic conductive adhesive. By doing so, sufficient adhesion can be ensured. Further, (ii) the content of the compound having a vinyl group and an alkoxy group can be, for example, 10% by weight or less, preferably 8% by weight or less, based on the total anisotropic conductive adhesive. By carrying out like this, corrosion of the metal part of the adherend surface can be suppressed, and sufficient insulation can be secured.

  In addition, (ii) when using only the compound which has a vinyl group and an alkoxy group as (b) adhesiveness imparting agent, the silane coupling agent which has a glycidyl group mentioned later or the silane coupling agent which has a mercapto group is further included. be able to. Thereby, adhesiveness can be improved further reliably.

  Further, when the above (i) and (ii) are used in combination, specifically, for example, the above (i) is contained in an amount of, for example, 5% by weight to 10% by weight of the total anisotropic conductive adhesive, ii) can be configured to include, for example, 5 wt% or more and 10 wt% or less of the entire anisotropic conductive adhesive.

  Next, as (c) organic peroxide, for example, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanate, t-butylperoxy-2-ethylhexanate, t-hexyl Peroxy-2-ethylhexanate, 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane, 1,1-bis (t-hexylperoxy) -3,3,5-trimethylcyclohexane And bis (4-t-butylcyclohexyl) peroxydicarbonate.

  These peroxides may be used alone. Moreover, in order to control curability, it is also possible to mix and use two or more types of organic peroxides. It is also possible to previously add various polymerization inhibitors to the anisotropic conductive adhesive. By doing so, the storage stability of (c) the organic peroxide can be improved. Furthermore, (c) the organic peroxide can also be used after diluted in a solvent or the like in order to facilitate the dissolving operation in the resin.

  In addition, the kind and compounding quantity of (c) organic peroxide can be suitably determined in consideration of the curability and preservability of the adhesive when each peroxide is blended.

  (C) Although the compounding quantity of an organic peroxide is not specifically limited, For example, 1 weight% or more of the whole anisotropically conductive adhesive agent, Preferably it can be 3 weight%. By doing so, the reactivity with the (a) radical polymerizable resin can be sufficiently ensured. Moreover, the compounding quantity of (c) organic peroxide can be 10 weight% or less of the whole anisotropically conductive adhesive, for example, Preferably it can be 8 weight% or less. By carrying out like this, it can be made to react stably with (a) radically polymerizable resin.

  Next, as the conductive particles (d), for example, particles made of one or more metals selected from the group consisting of gold, silver, zinc, tin, solder, indium, and palladium can be used. For example, (d) as a material for the conductive particles, these metals may be used alone, or an alloy composed of two or more metals may be used.

  Further, (d) the conductive particles may be particles in which a core of a polymer material is coated with a metal. The metal that coats the core may be, for example, one or more metals selected from the group consisting of gold, nickel, silver, copper, zinc, tin, indium, palladium, and aluminum. These metals may be used alone, or an alloy composed of two or more metals may be used.

  Although the thickness of the metal to coat | cover is not specifically limited, For example, it is 0.01 micrometer or more, Preferably it can be 0.05 micrometer or more. By doing so, connection reliability can be sufficiently secured. Moreover, the thickness of the metal to coat | cover can be 1.0 micrometer or less, for example, Preferably it is 0.8 micrometer or less. By carrying out like this, aggregation of electroconductive particles can be suppressed suitably. Furthermore, it is preferable that the surface of the core is uniformly coated with a metal. By doing so, it is possible to reliably suppress the presence of unevenness or chipping in the metal thin film and stabilize the connection.

(D) The particle diameter, material, and blending amount of the conductive particles can be appropriately selected based on the pitch and pattern of the circuit to be connected, the thickness and material of the circuit terminal, and the like. For example, when used in a display device such as the periphery of a liquid crystal display panel, the surface of resin particles having an average particle diameter (d ₅₀ ) of, for example, 1 μm or more and 10 μm or less, preferably 3 μm or more and 6 μm or less is used. Can do. By doing so, the conductivity of the anisotropic conductive adhesive can be further improved.

  (D) Although content of electroconductive particle is not specifically limited, For example, 0.1 weight% or more of the whole anisotropically conductive adhesive agent, Preferably it can be 1 weight% or more. By doing so, it is possible to sufficiently secure the number of conductive particles contributing to connection and improve connection reliability. Further, the content of (d) conductive particles can be, for example, 10% by weight or less, preferably 5% by weight or less of the whole anisotropically conductive adhesive. By doing so, electrical insulation between adjacent terminals can be sufficiently ensured.

  The anisotropic conductive adhesive of the present invention can further contain a thermoplastic elastomer. By doing so, a stable film can be formed. Moreover, the elastic modulus of resin after hardening can be lowered | hung and adhesive force can be improved. For this reason, the residual stress at the time of a connection can be made small and connection reliability can be improved.

(E) Specific examples of the thermoplastic elastomer include polyester-based thermoplastic elastomers such as polyester resins;
Polyurethane-based thermoplastic elastomers such as polyurethane resins;
Polyimide resin;
Polyolefin thermoplastic elastomers such as polybutadiene and polypropylene;
Styrene such as styrene-butadiene-styrene copolymer, acrylonitrile-butadiene-styrene copolymer, styrene-isoprene copolymer, styrene-butylene-styrene block copolymer, styrene-ethylene-butylene-styrene block copolymer Thermoplastic elastomers;
Polyacetal resin;
Polyvinyl butyral resin;
Synthetic rubbers such as butyl rubber and chloroprene rubber;
Polyamide resin such as nylon;
Acrylonitrile-butadiene-methacrylic acid copolymer;
Polyvinyl acetate resin;
Polymethyl methacrylate resin;
Phenoxy resins such as bisphenol A type phenoxy resin and fluorene skeleton-containing phenoxy resin;
Etc. These may be used alone or in combination.

  More specifically, among the above-mentioned elastomers, acrylonitrile-butadiene-methacrylic acid copolymer, polyester resin, polyamide resin, nylon, polyvinyl butyral resin, styrene-ethylene-butylene-styrene block copolymer, and phenoxy resin. It is preferable to use one or more thermoplastic elastomers selected from the group consisting of: By doing so, the adhesiveness and connection reliability of the anisotropic conductive adhesive can be further improved.

  (E) Although content of a thermoplastic elastomer is not specifically limited, For example, it can be 20 weight% or more of the whole anisotropically conductive adhesive agent, Preferably it can be 30 weight% or more. By doing so, it is possible to sufficiently ensure the flexibility when the film is formed. Further, the content of the thermoplastic elastomer can be, for example, 80% by weight or less, preferably 60% by weight or less of the whole anisotropically conductive adhesive. By doing so, it is possible to suppress a decrease in adhesive strength under high-temperature and high-humidity conditions and sufficiently ensure long-term connection reliability.

  Moreover, the anisotropic conductive adhesive of the present invention may contain a reactive monomer. The reactive monomer can be (a) a reactive monomer having reactivity to a radical polymerizable resin (f). (F) The reactive monomer can be a radically polymerizable monomer. By doing so, the heat resistance of the anisotropic conductive adhesive can be improved.

  As the radical polymerizable monomer, for example, various monomers having a (meth) acryloyl group can be used. Specifically, for example, an epoxy acrylate resin, a urethane acrylate resin, a (meth) acryloylated phenol novolak resin having a phenolic hydroxyl group, and the like can be used.

  In addition, as radical polymerizable monomers, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, glycerin di (meth) acrylate, triethylene Glycol di (meth) acrylate, pentaerythritol tri (meth) acrylate, isocyanuric acid ethylene glycol modified tri (meth) acrylate, methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) Acrylate, 2-ethylhexyl (meth) acrylate, isodecyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, benzyl (meth) acrylate, phenoxyethyl (meth) acrylate , Isobornyl (meth) acrylate, diethylaminoethyl (meth) acrylate or glycidyl (meth) may be used acrylate.

  Further, as the radical polymerizable monomer, a (meth) acrylic acid derivative having a cyclo ring structure, specifically, for example, dimethylol-tricyclodecane diacrylate or the like can be used. By using the (meth) acrylic acid derivative having a cyclo ring structure, the heat resistance of the anisotropic conductive adhesive can be further improved.

  As the radical polymerizable monomer, for example, one of the above compounds may be used, or two or more of the above compounds may be mixed and used.

  Moreover, you may add a suitable amount of coupling agents to the anisotropic conductive adhesive of this invention as needed. Thereby, the adhesiveness modification of the adhesion interface of anisotropic conductive adhesive, heat resistance, and moisture resistance can be improved.

Further, as the coupling agent, for example, a silane coupling agent can be preferably used. Specifically, glycidylsilane such as γ-glycidoxypropyltriethoxysilane;
epoxy silanes such as β- (3,4 epoxycyclohexyl) ethyltrimethoxysilane;
aminosilanes such as γ-aminopropyltriethoxysilane;
mercaptosilanes such as γ-mercaptopropyltrimethoxysilane;
Examples include ureidosilanes such as γ-ureidopropyltriethoxysilane. One of these may be used, or two or more may be mixed and used. Moreover, you may use the hydrolyzate of these silane coupling agents.

  Among these coupling agents, those having a mercapto group or a glycidyl group are preferably used. Moreover, the adhesiveness to metal surfaces, such as gold | metal | money and silver, can further be improved by using the silane coupling agent which has a mercapto group.

  Moreover, the anisotropic conductive adhesive of this invention may further contain the (meth) acryl compound which has organic acid as a compound other than the above. Thereby, the contact | adhesion power with respect to a to-be-adhered body interface, especially the contact | adhesion power with respect to the surface of a metal material can further be improved.

  Examples of the (meth) acrylic compound having an organic acid include β-acryloyloxyhydrogen succinate, β-methacryloyloxyethyl hydrogen succinate, β-methacryloyloxyethyl hydrogen phthalate, 2-acrylamido-2-methylpropanesulfone. Etc. Specifically, a compound represented by the formula (1) is preferable.

  Moreover, the anisotropic conductive adhesive of this invention may further contain the (meth) acryl compound which has a sulfur atom as compounds other than the above. Thereby, the adhesive force of an adherend interface, especially the adhesive force with respect to engineering plastics, such as a metal and a polyimide, can further be improved. The reason for this is not necessarily clear, but it is presumed that the sulfur atom has a strong polarity and thus strongly interacts with the hydroxyl group on the metal or organic surface.

  Examples of the (meth) acrylic compound having a sulfur atom include 2- (methylthio) ethyl methacrylate and 2- (methylthio) ethyl acrylate. Specifically, a compound represented by the formula (2) is preferable.

  Moreover, the anisotropic conductive adhesive which concerns on this invention may also contain various resin components other than resin mentioned above as a polymeric material. Specifically, for example, epoxy resins other than the above-described resins, urethane resins, melamine resins, phenol resins, polyester resins, polystyrene resins, styrene-butadiene copolymers, and the like can be used. These resins may be used alone or in combination of two or more.

  Furthermore, the anisotropic conductive adhesive of the present invention may contain compounds other than those described above. For example, various additives such as non-reactive diluents, reactive diluents, thixotropic agents, thickeners, inorganic fillers, etc. are added to improve various properties such as resin compatibility, stability and workability. You may add suitably.

  Next, a method for producing the anisotropic conductive adhesive according to the present invention will be described. An anisotropic conductive adhesive is obtained by uniformly dispersing an insulating adhesive containing a latent curing agent, conductive particles, and other additives as required in a solvent such as toluene or ethyl acetate. Moreover, the anisotropic conductive adhesive film which concerns on this invention apply | coats the obtained dispersion liquid on a peeling base material (for example, polyester sheet) in a film form, removes a solvent below the active temperature of a hardening | curing agent, and dries. Manufactured by.

  The obtained anisotropic conductive adhesive film has a structure in which conductive particles are dispersed in an insulating adhesive containing radically polymerizable resin, organic peroxide, and adhesion-imparting agent as essential components. It is excellent in short-time curability and adhesiveness, and has sufficient storage stability. For this reason, in electronic devices, such as a display apparatus, it is used suitably for the connection between members. For example, a display device in which the display member and the adherend are bonded can be obtained via the anisotropic conductive adhesive of the present invention. In addition, an electronic device in which the circuit board and the adherend are bonded can be obtained through the anisotropic conductive adhesive of the present invention. More specifically, for example, in a liquid crystal display device, it is preferably used for electrical connection between microcircuits such as connection between COF and PCB and connection between TCP and PCB.

  A display device which is one of electronic devices obtained using the anisotropic conductive adhesive of the present invention will be described. Here, a case where the display device is an LCD (liquid crystal display) module will be described as an example. FIG. 1 is a plan view schematically showing an example of the configuration of the LCD module of the present invention.

  The LCD module 10 includes an LCD panel 11 and a circuit board. The circuit board includes a TCP (tape carrier package) 12 and a PCB (printed circuit board) 13. The LCD panel 11 and the TCP 12 and the TCP 12 and the PCB 13 are bonded by an anisotropic conductive adhesive 14.

  FIG. 2 is a cross-sectional view taken along line A-A ′ of FIG. 1. As shown in FIG. 2, a TCP electrode 18 is provided as a circuit terminal on the surface of the TCP 12 facing the PCB 13. A PCB electrode 17 is provided as a circuit terminal on the surface of the PCB 13 facing the TCP 12. Although not shown in FIGS. 1 and 2, an ITO (indium tin oxide) electrode is provided as a circuit terminal on the surface of the LCD panel 11 facing the TCP 12.

  The anisotropic conductive adhesive 14 includes an adhesive resin 16 and conductive particles 15 dispersed in the adhesive resin 16. The ITO electrode (not shown) and the TCP electrode 18 or the TCP electrode 18 and the PCB electrode 17 are electrically connected through the anisotropic conductive adhesive 14. Since the anisotropic conductive adhesive 14 includes the conductive particles 15, electrical connection between the circuit terminals is ensured.

  Thus, the anisotropic conductive adhesive 14 can be suitably used as a connection member around the display device. Further, the anisotropic conductive adhesive 14 according to the present invention can be more suitably used as an input connection member for connecting the TCP 12 and the PCB 13.

  In FIG. 1, the LCD panel 11 is used as the display device substrate. However, the present invention is not limited to this, and can be applied to, for example, an electroluminescence panel, a plasma display panel, and the like.

  Although the anisotropic conductive adhesive according to the present invention has been described above, any combination of these components, and the components and expressions of the present invention that are mutually replaced between methods and apparatuses are also described in this document. This is effective as an aspect of the invention.

  For example, according to the present invention, there is provided an electronic apparatus characterized in that a circuit board and an adherend are bonded via the anisotropic conductive adhesive. In the present invention, the electronic device is a semiconductor element, a semiconductor device, a printed circuit board, a liquid crystal display (LCD), a panel, a plasma display (PDP) panel, an electroluminescence (EL) panel, or a field emission display (FED) panel. There may be.

  Moreover, according to this invention, the display member and the to-be-adhered body are joined through the said anisotropically conductive adhesive agent, The display apparatus characterized by the above-mentioned is provided.

  In the present invention, the adherend may be a semiconductor element or a circuit board.

  Hereinafter, although this invention is demonstrated in detail based on an experiment example, this invention is not limited to this.

(Experimental example 1)
As shown in Table 1,
Thermoplastic elastomer: acrylonitrile-butadiene-methacrylic acid copolymer (manufactured by JSR, having a structure represented by the following formula (3)) 30% by weight,
Thermoplastic elastomer: bisphenol A type phenoxy resin 20% by weight,
Radical polymerizable resin: 35% by weight of methacryloylated phenol novolak resin,
Organic peroxide: 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate (Nippon Yushi Perocta O) 2% by weight,
Adhesion imparting agent: terminal acryloyl group-type styrene-acrylonitrile copolymer (one having an acryloyl group bonded to one end of a styrene-acrylonitrile copolymer, molecular weight 6000) 1% by weight,
Adhesion imparting agent: 10% by weight of γ-acryloxypropyltrimethoxysilane (KBM-5103 manufactured by Shin-Etsu Chemical Co., Ltd.) and conductive particles: Ni / Au plating coated benzoguanamine resin particles (GNR-EH manufactured by Nippon Chemical Industry Co., Ltd., average particle diameter) 5 μm) 2% by weight,
The resin composition consisting of was uniformly dispersed in methyl ethyl ketone. Moreover, the obtained resin varnish was apply | coated so that the thickness after drying might be set to 15 micrometers on the polyethylene terephthalate which gave the mold release process, and it dried. The dried product was cut into a width of 1.5 mm to obtain an anisotropic conductive adhesive film.

(However, in said formula (3), it is 1:27 weight%, n: 4.0 mol%, molecular weight: 100,000.)

(Experimental example 2)
In the formulation of Experimental Example 1, 41% by weight of methacryloylated phenol novolak resin, 3% by weight of terminal acryloyl group-type styrene-acrylonitrile copolymer, and 2% by weight of γ-acryloxypropyltrimethoxysilane. In the same manner as in Experimental Example 1, a film-like anisotropic conductive adhesive was obtained.

(Experimental example 3)
In Experimental Example 1, 1% by weight of γ-mercaptopropyltrimethoxysilane was added as a coupling agent in place of the terminal acryloyl group-type styrene-acrylonitrile copolymer. A film-like anisotropic conductive adhesive was obtained in the same manner as in Experimental Example 1 with the blending ratio shown in Table 1.

(Experimental example 4)
Experimental Example 1 was the same as Experimental Example 1 except that 36% by weight of methacryloylated phenol novolak resin, 10% by weight of a terminal acryloyl group-type styrene-acrylonitrile copolymer was used, and γ-acryloxypropyltrimethoxysilane was not used. A film-like anisotropic conductive adhesive was obtained.

(Experimental example 5)
In Experimental Example 4, 43% by weight of a methacryloylated phenol novolak resin, 2% by weight of a terminal acryloyl group-type styrene-acrylonitrile copolymer, and 1% by weight of γ-mercaptopropyltrimethoxysilane were added as a coupling agent. A film-like anisotropic conductive adhesive was obtained in the same manner as in Experimental Example 1 with the blending ratio shown in Table 1.

(Experimental example 6)
In Experimental Example 4, 35% by weight of methacryloylated phenol novolak resin was added, and 1% by weight of β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane (KBM-303 manufactured by Shin-Etsu Chemical) was added as a coupling agent. A film-like anisotropic conductive adhesive was obtained in the same manner as in Experimental Example 1 with the blending ratio shown in Table 1.

(Experimental example 7)
In Experimental Example 6, the adhesion-imparting agent was blended in an amount of 5% by weight of a terminal acryloyl group-type styrene-acrylonitrile copolymer and 5% by weight of γ-acryloxypropyltrimethoxysilane. An anisotropic conductive adhesive film was prepared in the same manner as in Experimental Example 1 with the formulation shown in Table 1.

(Experimental example 8)
In Experimental Example 7, methacryloylated phenol novolak resin was 30% by weight and terminal acryloyl group-type styrene-acrylonitrile copolymer was 10% by weight. An anisotropic conductive adhesive film was prepared in the same manner as in Experimental Example 3 with the formulation shown in Table 1.

(Experimental example 9)
In Experimental Example 7, instead of the terminal acryloyl group-type styrene-acrylonitrile copolymer, 5% by weight of dimethylol-tricyclodecanediacrylate (DCE-A manufactured by Kyoei Chemical Co., Ltd.), which is a radical polymerizable monomer, was added as a reactive monomer. It was. An anisotropic conductive adhesive film was prepared in the same manner as in Experimental Example 1 with the formulation shown in Table 1.

(Experimental example 10)
In Experimental Example 7, methacryloylated phenol novolak resin was 25% by weight, and 10% by weight of dimethylol-tricyclodecane diacrylate as a radical polymerizable monomer was used as a reactive monomer. An anisotropic conductive adhesive film was prepared in the same manner as in Experimental Example 1 with the formulation shown in Table 1.

(Experimental example 11)
In Experimental Example 7, γ-mercaptopropyltrimethoxysilane was used in place of β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane as a coupling agent. An anisotropic conductive adhesive film was prepared in the same manner as in Experimental Example 1 with the formulation shown in Table 1.

(Experimental example 12, 14-22)
In each of Experimental Examples 1 to 11, a fluorene skeleton-containing phenoxy resin (weight average molecular weight 50,000) was used as the thermoplastic elastomer in place of the acrylonitrile-butadiene-methacrylic acid copolymer. Further, as the radical polymerizable resin, a urethane acrylate resin (bifunctional acrylate, molecular weight 3000) was used in place of the methacryloylated phenol novolac resin. Further, as an adhesion-imparting agent, a terminal methacryloyl group-type styrene-acrylonitrile copolymer (one having a methacryloyl group bonded to one end of a styrene-acrylonitrile copolymer, molecular weight instead of a terminal acryloyl group-type styrene-acrylonitrile copolymer) 6000), and γ-methacryloxypropyltrimethoxysilane (KBM-503 manufactured by Shin-Etsu Chemical Co., Ltd.) was used instead of γ-acryloxypropyltrimethoxysilane. An anisotropic conductive adhesive film was prepared in the same manner as in Experimental Examples 1 to 11 with the formulation shown in Table 2, respectively.

(Experimental example 13)
In Experimental Example 2, 42% by weight of a fluorene skeleton-containing phenoxy resin (weight average molecular weight 50,000) was blended as a thermoplastic elastomer in place of the acrylonitrile-butadiene-methacrylic acid copolymer. Further, as the radical polymerizable resin, a urethane acrylate resin (bifunctional acrylate, molecular weight 3000) was used in place of the methacryloylated phenol novolac resin. Further, as an adhesion-imparting agent, a terminal methacryloyl group-type styrene-acrylonitrile copolymer (one having a methacryloyl group bonded to one end of a styrene-acrylonitrile copolymer, molecular weight instead of a terminal acryloyl group-type styrene-acrylonitrile copolymer) 6000) and 1% by weight of γ-methacryloxypropyltrimethoxysilane was added instead of γ-acryloxypropyltrimethoxysilane. An anisotropic conductive adhesive film was prepared in the same manner as in Experimental Example 1 with the formulation shown in Table 2.

(Experimental example 23)
In Experimental Example 3, 1% by weight of γ-acryloxypropyltrimethoxysilane was blended as an adhesion-imparting agent, and 10% by weight of β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane was blended as a coupling agent. . An anisotropic conductive adhesive film was prepared in the same manner as in Experimental Example 1 with the formulation shown in Table 3.

(Experimental example 24)
In Experimental Example 23, 5 wt. Of a terminal methacryloyl group-type styrene polymer (one having a methacryloyl group bonded to one end of a styrene polymer) instead of γ-acryloxypropyltrimethoxysilane as an adhesion-imparting agent. % Blended. Further, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane was 6% by weight. An anisotropic conductive adhesive film was prepared in the same manner as in Experimental Example 1 with the formulation shown in Table 3.

(Experimental example 25)
In Experimental Example 24, 30% by weight of a methacryloylated phenol novolak resin and 10% by weight of a terminal methacryloyl group-type styrene polymer were used. An anisotropic conductive adhesive film was prepared in the same manner as in Experimental Example 1 with the formulation shown in Table 3.

(Experimental examples 26 to 28)
In each of Experimental Examples 23 to 25, a fluorene skeleton-containing phenoxy resin was used as the thermoplastic elastomer in place of the acrylonitrile-butadiene-methacrylic acid copolymer. Further, as the radical polymerizable resin, a urethane acrylate resin was used in place of the methacryloylated phenol novolak resin. An anisotropic conductive adhesive film was prepared in the same manner as in Experimental Examples 23 to 25 with the formulation shown in Table 3, respectively.

  Tables 1 to 3 show the experimental examples and the components and blending ratios (weight ratios) of the anisotropic conductive adhesives prepared in the respective experimental examples. Moreover, the following evaluation was performed about the anisotropically conductive adhesive obtained by each experiment example. Evaluation items and results are shown in Tables 1 to 3.

Preparation of Evaluation Sample An evaluation sample was prepared in advance as follows. Copper foil / polyimide = 25/75 μm with 0.5 μm tin plated TCP (pitch 0.30 mm, 60 terminals), 0.8 mm thick 4-layer board (FR-4) inner layer, outer layer copper foil 18 μm Flash gold-plated PCB (pitch 0.30 mm, number of terminals 60) was joined with the anisotropic conductive adhesive obtained in each experimental example.

The adhesive strength was 150 ° C., 3 MPa, and 10 seconds, and evaluation was performed by a 90 ° peel test at a pulling speed of 50 mm / min. As an initial value, the adhesive force in an atmosphere of 25 ° C. and 80 ° C. immediately after the sample was prepared was measured. The measured value at 80 ° C. is an index of heat resistance. Moreover, the adhesive force after a temperature-85 degreeC, humidity 85%, and a 500-hour leaving process (after HH process) was measured.

Connection Reliability The connection resistance was measured immediately after the sample was prepared and after being left at a temperature of 85 ° C. and a humidity of 85% for 500 hours (after HH treatment). A case where the connection resistance was less than 2.0Ω was evaluated as “Good” (conducting good), a case where it was 2.0Ω or more and less than 5.0Ω, and a case where it was 5.0Ω or more were evaluated as “Poor” (conducting failure).

Preservability Preservability was determined by allowing the obtained anisotropic conductive adhesive to stand in an atmosphere at 25 ° C. for 2 weeks, and then press bonding under conditions of 150 ° C., 3 MPa, and 10 seconds, and measuring connection resistance. The case where the connection resistance was less than 2.0Ω was evaluated as “Good” (good storage stability), the case where it was 2.0Ω or more and less than 5.0Ω was Δ, and the case where it was 5.0Ω or more was evaluated as “Poor” (storability poor).

  Moreover, TCB and PCB were connected using the anisotropic conductive adhesive film which concerns on Experimental Examples 1-22, and the display apparatus member was obtained. The anisotropic conductive adhesive film was adhered at 150 ° C., 3 MPa, and 10 seconds. The obtained display device member was provided with peripheral members such as a power source and a backlight to obtain a liquid crystal display device.

  In the obtained liquid crystal display device, good adhesion between TCB and PCB was obtained. From this, it turned out that the anisotropic conductive adhesive film which concerns on Experimental Examples 1-22 can be utilized suitably as an anisotropic conductive adhesive film for an output.

It is a top view which shows typically an example of a structure of the LCD module of this invention. It is A-A 'sectional drawing of FIG.

Explanation of symbols

11 LCD panel 12 TCP
13 PCB
14 Anisotropic Conductive Adhesive 15 Conductive Particles 16 Adhesive Resin 17 PCB Electrode 18 TCP Electrode

Claims (11)

(A) radical polymerizable resin,
(B) an adhesion-imparting agent,
(C) an organic peroxide, and (d) conductive particles,
As an essential component,
The anisotropic conductive adhesive, wherein (b) the adhesion-imparting agent contains a compound having a vinyl group and a nitrile group.   2. The anisotropic conductive adhesive according to claim 1, wherein the compound having a vinyl group and a nitrile group is a radical polymerizable macromonomer.   The anisotropic conductive adhesive according to claim 1 or 2, wherein the compound having a vinyl group and a nitrile group is a macromonomer of a (meth) acrylic compound. In the anisotropic conductive adhesive in any one of Claims 1 thru | or 3,
The anisotropic conductive adhesive, wherein the (b) adhesion-imparting agent further comprises a compound having a vinyl group and an alkoxy group.   5. The anisotropic conductive adhesive according to claim 1, further comprising a silane coupling agent having a glycidyl group or a silane coupling agent having a mercapto group. (A) radical polymerizable resin,
(B) an adhesion-imparting agent,
(C) an organic peroxide,
(D) containing conductive particles and a silane coupling agent having a glycidyl group or a silane coupling agent having a mercapto group as essential components;
(B) The adhesion imparting agent contains a compound having a vinyl group and an alkoxy group, and an anisotropic conductive adhesive. The anisotropic conductive adhesive according to any one of claims 1 to 6,
(E) An anisotropic conductive adhesive further comprising a thermoplastic elastomer.   The anisotropic conductive adhesive according to any one of claims 1 to 7, wherein (a) the radical polymerizable resin is an epoxy acrylate resin, a (meth) acryloylated phenol novolak resin having a phenolic hydroxyl group, and a urethane acrylate resin. An anisotropic conductive adhesive, which is one or more resins selected from the group consisting of: In the anisotropic conductive adhesive according to claim 8,
An anisotropic conductive adhesive, further comprising (f) a reactive monomer, wherein the (f) reactive monomer comprises a (meth) acrylic acid derivative.   The anisotropic conductive adhesive according to claim 9, wherein the reactive monomer contains a compound having a cycloalkyl group.   An anisotropic conductive adhesive film according to any one of claims 1 to 10, wherein the anisotropic conductive adhesive film is formed into a film shape.

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