KR102397238B1 - Adhesive composition and connector - Google Patents

Abstract

The present invention is an adhesive composition comprising (a) a thermoplastic resin, (b) a radically polymerizable compound, and (c) a radical polymerization initiator, wherein the (b) radically polymerizable compound is a radically polymerizable compound having an isocyanate group, or It relates to an adhesive composition comprising a radically polymerizable compound having a structure in which an isocyanate group is generated by heating.

Description

Adhesive composition and connector

The present invention relates to adhesive compositions and connectors.

In a semiconductor device or a liquid crystal display device, various adhesive compositions have been conventionally used as circuit connection materials for the purpose of bonding various members in the device. Various characteristics, such as adhesiveness, heat resistance, and reliability in a high-temperature, high-humidity state, are calculated|required of this adhesive composition.

The adherend to be adhered has various surfaces formed of various materials such as printed wiring boards, organic materials such as polyimide films, metals such as copper and aluminum, and metal compounds such as ITO, SiN, and SiO ₂ . Therefore, the adhesive composition is designed according to each to-be-adhered body.

As an adhesive composition for semiconductor elements or liquid crystal display elements, the thermosetting resin composition containing thermosetting resins, such as an epoxy resin which shows high adhesiveness and high reliability, is known (for example, refer patent document 1). Such an adhesive composition generally contains an epoxy resin, a curing agent such as a phenol resin that reacts with the epoxy resin, and a thermal latent catalyst that promotes the reaction between the epoxy resin and the curing agent. Among them, the thermal latent catalyst is an important factor determining the curing temperature and curing rate. Therefore, as a thermal latent catalyst, various compounds are used from a viewpoint of the storage stability at room temperature, and the curing rate at the time of heating. This adhesive composition is hardened|cured by heating at the temperature of 170-250 degreeC in general for 1 to 3 hours, and exhibits desired adhesiveness.

Moreover, the radical curing adhesive agent containing a (meth)acrylate derivative and a peroxide attracts attention (for example, refer patent document 2). A radical curing adhesive is advantageous from a viewpoint of short-time hardening, since the radical which is a reactive active species has many reactivity.

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

With the recent high integration of semiconductor devices and high precision of liquid crystal devices, the pitch between devices and between wirings is narrowing, and the possibility that heating during curing for circuit connection will adversely affect peripheral members is increasing.

Moreover, in order to reduce cost, it is necessary to improve a throughput, and development of the adhesive composition which is lower temperature and cures in a short time, in other words, the adhesive composition of "low temperature fast curing" is calculated|required.

In order to achieve low-temperature rapid curing of the adhesive composition, for example, in the thermosetting resin composition, a thermal latent catalyst having a low activation energy is sometimes used, but in this case, it is very difficult to maintain storage stability around room temperature. it's difficult.

On the other hand, a radical curing adhesive can achieve low-temperature rapid hardening, having storage stability of the level which does not have a problem practically. However, even in the case of using a radical-curable adhesive, when curing is performed at a lower temperature (for example, 140° C. or less) compared to the conventional one, the radically polymerizable compound in the adhesive is mostly reacted with the adherend, although The adhesive strength of the adhesive may not be obtained. It is considered that this is because the interaction between the adherend and the adhesive is not sufficiently expressed under low-temperature conditions.

The present invention has been made in view of the problems of the prior art, and in a radical curing adhesive, the adhesive strength between the adherend and the adhesive is sufficiently improved even at a lower temperature (for example, 140° C. or less) compared to the prior art. An object of the present invention is to provide an adhesive composition that can be expressed.

The present invention is an adhesive composition comprising (a) a thermoplastic resin, (b) a radically polymerizable compound, and (c) a radical polymerization initiator, wherein (b) the radically polymerizable compound is a radically polymerizable compound having an isocyanate group or heating To provide an adhesive composition comprising a radically polymerizable compound having a structure in which an isocyanate group is generated. According to such an adhesive composition, compared with the past, the adhesive strength of a to-be-adhered body and an adhesive agent can fully be expressed also even under the conditions of further low temperature (for example, 140 degrees C or less).

Content of the radically polymerizable compound which has an isocyanate group or the radically polymerizable compound which has a structure in which an isocyanate group is produced|generated by heating is 2 with respect to 100 mass parts of total amounts of (a) thermoplastic resin and (b) radically polymerizable compound It is preferable that it is -12 mass parts. By making content into this range, the effect mentioned above becomes larger.

The adhesive composition of this invention may contain (d) electroconductive particle further. Since electroconductivity or anisotropic electroconductivity can be provided to an adhesive composition by further containing electroconductive particle, an adhesive composition can be used more suitably as a circuit connection material. Moreover, the connection resistance between the circuit electrodes electrically connected through the said adhesive composition can be reduced more easily.

The present invention also provides a first circuit member in which a first circuit electrode is formed on a main surface of a first circuit board, a second circuit electrode is formed on a main surface of a second circuit board, and a second circuit electrode and a first circuit electrode A second circuit member disposed to face the second circuit member, and a connection member provided between the first circuit member and the second circuit member to electrically connect the first circuit member and the second circuit member, the connection member comprising: A connection body, which is a cured product of the adhesive composition of the present invention, is provided. Moreover, it is preferable here that one of a said 1st circuit board and a said 2nd circuit board is a flexible board|substrate.

In the connector according to the present invention, since the connecting member for electrically connecting the first circuit member and the second circuit member is constituted by the cured product of the adhesive composition of the present invention, each circuit member and the adhesive composition are cured The adhesive strength of water is fully expressed.

According to the present invention, it is possible to provide an adhesive composition in which the adhesive strength between the adherend and the adhesive is sufficiently exhibited and a sufficiently high connection reliability is obtained even under conditions of a lower temperature (for example, 140° C. or less) compared to the prior art. there is. Moreover, according to such an adhesive composition, even when it adheres to a to-be-adhered body and when it carries out high-temperature, high-humidity process, the fall of adhesive strength and connection reliability is fully suppressed, Furthermore, it is excellent in a pot life.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic sectional drawing which shows one Embodiment of the film adhesive containing the adhesive composition which concerns on this embodiment.
Fig. 2 is a schematic cross-sectional view showing one embodiment of a connecting body in which the adhesive composition according to the present embodiment includes a connecting member including a cured product.
It is a process diagram which shows one Embodiment of manufacturing a connector with the adhesive composition which concerns on this embodiment by schematic sectional drawing.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings as necessary. However, this invention is not limited to the following embodiment. In the drawings, the same or equivalent parts are denoted by the same reference numerals, and overlapping explanations are omitted as appropriate. In addition, in this specification, (meth)acrylic acid means acrylic acid or methacrylic acid corresponding thereto. The same applies to other analogous expressions such as (meth)acrylate.

The adhesive composition which concerns on this embodiment contains (a) thermoplastic resin, (b) radically polymerizable compound, and (c) radical polymerization initiator.

As the (a) thermoplastic resin, for example, polyimide resin, polyamide resin, phenoxy resin, poly(meth)acrylic resin, polyester resin, polyurethane resin, polyester urethane resin, and polyvinyl butyral resin and one or more resins selected from Among them, it is preferable to include (a) as the thermoplastic resin, a polyimide resin, a polyamide resin, a phenoxy resin, a poly(meth)acrylic resin, a polyurethane resin, a polyester urethane resin, or a polyvinyl butyral resin.

5000 or more may be sufficient as the lower limit of the weight average molecular weight of a thermoplastic resin, 10000 or more may be sufficient as it, and 25000 or more may be sufficient as it. It exists in the tendency for the adhesive strength of an adhesive composition to improve that the weight average molecular weight of a thermoplastic resin is 5000 or more. In addition, 400000 or less may be sufficient as the upper limit of the weight average molecular weight of a thermoplastic resin, 200000 or less may be sufficient as it, and 150000 or less may be sufficient as it. When the weight average molecular weight of the thermoplastic resin is 400000 or less, good compatibility with other components tends to be easily obtained, and fluidity of the adhesive tends to be easily obtained. 5000-40000 are preferable, as for the weight average molecular weight of said viewpoint to a thermoplastic resin, 5000-20000 are more preferable, 10000-150000 are still more preferable, 25000-150000 are especially preferable.

As the thermoplastic resin, a rubber component may be used for the purpose of stress relief and adhesion improvement.

It is preferable that content of a thermoplastic resin is 20-80 mass parts with respect to 100 mass parts of total amounts of (a) component and (b) component, It is more preferable that it is 30-70 mass parts, It is more preferable that it is 35-65 mass parts desirable. If the content of the thermoplastic resin is 20 parts by mass or more, the adhesive strength tends to improve or the film formability of the adhesive composition tends to improve, and if it is 80 parts by mass or less, the fluidity of the adhesive tends to be easily obtained.

The adhesive composition which concerns on this embodiment contains the radically polymerizable compound which has a structure in which an isocyanate group produces|generates by the radically polymerizable compound or heating which has an isocyanate group as (b) radically polymerizable compound.

It is preferable that the said radically polymerizable compound contains at least 1 sort(s) of the compound which has an isocyanate group or the structure in which an isocyanate group produces|generates by heating, and a radically polymerizable unsaturated group. The radically polymerizable unsaturated group is preferably a (meth)acryloyl group, more preferably a (meth)acryloyloxy group.

As a method for producing a compound having an isocyanate group and a (meth)acryloyloxy group, as described in Japanese Patent Application Laid-Open No. 2006-232797, a method of reacting a salt of an ester of (meth)acrylic acid with an amino alcohol and phosgene , a method of reacting isopropenyloxazoline with phosgene, a method of dehydrochlorination of a 3-chloropropionic acid ester derivative having an isocyanate group, and the like.

It is preferable that the molecular weights of the compound which have an isocyanate group and a (meth)acryloyloxy group are 150 or more and less than 1000. There exists a tendency for a compound to become difficult to volatilize in the manufacturing process of an adhesive composition that the said molecular weight is 150 or more. When the said molecular weight is less than 1000, there exists a tendency for sufficient fluidity|liquidity to be easy to be obtained at the time of heating.

In the compound having an isocyanate group and a (meth)acryloyloxy group, the number of isocyanate groups and (meth)acryloyloxy groups in the molecule is not particularly limited, but it is practical that each independently about 1 to 5 pieces.

As a compound which has an isocyanate group and a (meth)acryloyloxy group, 2-(meth)acryloyloxyethyl isocyanate, 2-(meth)acryloyloxymethyl isocyanate, 2-(meth)acryloyloxy Propyl isocyanate, 1, 1- (bisacryloyloxymethyl) ethyl isocyanate, etc. are mentioned.

The adhesive composition which concerns on this embodiment may contain the radically polymerizable compound which has a structure in which an isocyanate group produces|generates by heating as (b) a radically polymerizable compound. The use of these compounds can further improve the pot life of the adhesive.

The structure in which an isocyanate group is produced|generated by heating can be synthesize|combined by making an isocyanate group chemically block with a blocking agent etc. Examples of the blocking agent include dimethyl pyrazole, dimethyl malonate, diethyl malonate, methyl ethyl ketone oxime and caprolactam. Since the temperature at which the blocking agent dissociates can be controlled depending on the type of blocking agent, these blocking agents can be used individually or in combination of two or more types according to the practical temperature.

As the compound having a structure in which an isocyanate group is generated by heating and a (meth)acryloyloxy group synthesized by the above method, for example, a compound having an isocyanate group and (meth)acryloyloxy group described above is used as the blocking agent. blocked compounds. Specific examples thereof include 2-(0-[1'-methylpropylideneamino]carboxyamino)ethyl (meth)acrylic acid.

The total content of the radically polymerizable compound having an isocyanate group or a radically polymerizable compound having a structure in which an isocyanate group is generated by heating is 2 to 12 parts by mass based on 100 parts by mass of the total amount of (a) component and (b) component It is preferable, It is more preferable that it is 3.5-10 mass parts, It is still more preferable that it is 4-9 mass parts. There exists a tendency for adhesive strength with a to-be-adhered body to become it higher that the said content is 2 mass parts or more. When the content is 12 parts by mass or less, the pot life of the adhesive tends to be further improved, and generation of bubbles after curing can be suppressed, and better connection reliability can be obtained.

The adhesive composition according to the present embodiment is added to the radically polymerizable compound having an isocyanate group or a radically polymerizable compound having a structure in which an isocyanate group is generated by heating, (b) as the radically polymerizable compound, a radically polymerizable functional group It may contain any other compound with The other compound may be, for example, either a monomer or an oligomer of a compound described later, or a combination of both.

As said compound, the 1 type(s) or 2 or more types of polyfunctional (meth)acrylate compound which has 2 or more (meth)acryloyloxy groups are preferable. As such (meth)acrylate compound, for example, epoxy (meth)acrylate, urethane (meth)acrylate, polyether (meth)acrylate, polyester (meth)acrylate, trimethylolpropane tri(meth)acryl Polyalkylene glycol di(meth)acrylate, dicyclopentenyl(meth)acrylate, dicyclopentenyloxyethyl(meth)acrylate, neopentylglycoldi(meth)acrylate, and meth)acrylate, dipentaerythritol hexa(meth)acrylate, isocyanuric acid-modified bifunctional (meth)acrylate, and isocyanuric acid-modified trifunctional (meth)acrylate. As said epoxy (meth)acrylate, the epoxy (meth)acrylate which added (meth)acrylic acid to two glycidyl groups of bisphenol fluorenediglycidyl ether, and bisphenol fluorenediglycidyl ether, for example, The compound which introduce|transduced the (meth)acryloyloxy group to the compound which added ethylene glycol and/or propylene glycol to two glycidyl groups is mentioned. These compounds can be used individually by 1 type or in combination of 2 or more type.

In addition, the adhesive composition may contain a monofunctional (meth)acrylate compound as (b) a radically polymerizable compound for the purpose of controlling fluidity or the like. Examples of the monofunctional (meth)acrylate compound include pentaerythritol (meth)acrylate, 2-cyanoethyl (meth)acrylate, cyclohexyl (meth)acrylate, and dicyclopentenyl (meth)acrylate. , 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, hydroxypropyl (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, one glycidyl group of an epoxy resin having a plurality of glycidyl groups The glycidyl group containing (meth)acrylate and (meth)acryloylmorpholine obtained by making it react with (meth)acrylic acid are mentioned. These compounds can be used individually by 1 type or in combination of 2 or more type.

In addition, the adhesive composition may contain a compound having a radically polymerizable functional group such as an allyl group, a maleimide group or a vinyl group as the radically polymerizable compound (b) for the purpose of improving the crosslinking rate or the like.

It is preferable that an adhesive composition contains the radically polymerizable compound which has a phosphoric acid group as (b) radically polymerizable compound for the purpose of the improvement of adhesive strength. As a radically polymerizable compound which has a phosphoric acid group, the compound represented by following formula (1), (2), or (3) is mentioned, for example.

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

In Formula (2), R< ⁷ > represents a (meth)acryloyloxy group, and y and z represent the integer of 1-8 each independently. A plurality of R ⁷ , y and z in the same molecule may be the same or different from each other.

In formula ( ³ ), ^R8 represents a hydrogen atom or a methyl group, R9 represents a (meth)acryloyloxy group, b and c each independently represent the integer of 1-8. A plurality of R ⁸ and b in the same molecule may be the same or different.

As a radically polymerizable compound which has a phosphoric acid group, for example, acid phosphooxyethyl (meth) acrylate, acid phosphooxypropyl (meth) acrylate, acid phosphooxy polyoxyethylene glycol mono (meth) acrylate, acid Phosphooxypolyoxypropylene glycol mono (meth) acrylate, 2,2'-di (meth) acryloyloxy diethyl phosphate, EO (ethylene oxide) modified phosphoric acid di (meth) acrylate, phosphoric acid modified epoxy (meth) acrylate and vinyl phosphate. These compounds can be used individually by 1 type or in combination of 2 or more type.

It is preferable that it is 0.1-15 mass parts with respect to 100 mass parts of total amounts of (a) component and (b) component, as for content of the radically polymerizable compound which has a phosphoric acid group, It is more preferable that it is 0.5-10 mass parts, It is more preferable, 1-5 It is more preferable that it is a mass part. When the content of the radically polymerizable compound having a phosphoric acid group is 0.1 parts by mass or more, high adhesive strength tends to be easily obtained, and when it is 15 parts by mass or less, it is difficult to decrease the physical properties of the adhesive composition after curing, and the effect of improving reliability is get better

The total content of the (b) radically polymerizable compound contained in the adhesive composition is preferably 20 to 80 parts by mass, and more preferably 30 to 70 parts by mass with respect to 100 parts by mass of the total amount of the component (a) and the component (b). It is preferable, and it is still more preferable that it is 35-65 mass parts. When this total content is 20 mass parts or more, there exists a tendency for heat resistance to improve, and if it is 80 mass parts or less, there exists a tendency for the effect of peeling suppression after leaving to stand in a high-temperature, high-humidity environment to become large.

(c) A radical polymerization initiator can be arbitrarily selected from compounds, such as a peroxide and an azo compound. From the viewpoint of stability, reactivity and compatibility, a peroxide having a half-life temperature of 90 to 175° C. for 1 minute and a molecular weight of 180 to 1000 is preferable. "One-minute half-life temperature" means the temperature at which the half-life of a peroxide is 1 minute. "Half-life" means the time until the concentration of the compound decreases to half of the initial value at a predetermined temperature.

As the radical polymerization initiator, for example, 1,1,3,3-tetramethylbutylperoxyneodecanoate, di(4-t-butylcyclohexyl)peroxydicarbonate, di(2-ethylhexyl)per Oxydicarbonate, cumylperoxyneodecanoate, 1,1,3,3-tetramethylbutylperoxyneodecanoate, dilauroyl peroxide, 1-cyclohexyl-1-methylethylperoxyneode Canoate, t-hexylperoxyneodecanoate, t-butylperoxyneodecanoate, t-butylperoxypivalate, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexano ate, 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-butylperoxyhexahydro terephthalate, t-amylperoxy-3,5,5-trimethylhexanoate Eate, 3-hydroxy-1,1-dimethylbutylperoxyneodecanoate, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, t-amylperoxyneodecanoate , t-amyl peroxy-2-ethylhexanoate, 3-methylbenzoyl peroxide, 4-methylbenzoyl peroxide, di (3-methylbenzoyl) peroxide, dibenzoyl peroxide, di (4-methylbenzoyl) 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-cyclohexanecarbonitrile), 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-hexylperoxybenzo ate, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, t-butylperoxybenzoate, dibutylperoxytrimethyladipate, t-amylperoxynormaloctoate, t-amylperoxyi selected from sononanoate and t-amylperoxybenzoate is one or more compounds.

It is preferable that content of a radical polymerization initiator is 1-15 mass parts with respect to 100 mass parts of total amounts of (a) component and (b) component, It is more preferable that it is 2.5-10 mass parts, It is more preferable that it is 3-8 mass parts desirable.

The adhesive composition which concerns on this embodiment may contain the silane coupling agent. The silane coupling agent is preferably a compound represented by the following formula (4).

In formula (4), R ¹ , R ² and R ³ each independently represent a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, an alkoxycarbonyl group having 1 to 5 carbon atoms, or an aryl group. At least one of R ¹ , R ² and R ³ is an alkoxy group. R ⁴ is a (meth)acryloyl group, a (meth)acryloyloxy group, a vinyl group, an isocyanato group, an imidazole group, a mercapto group, an amino group optionally substituted with an aminoalkyl group, a methylamino group, a dimethylamino group, or a benzylamino group , a phenylamino group, a cyclohexylamino group, a morpholino group, a piperazino group, a ureide group, a glycidyl group or a glycidoxy group. a represents the integer of 0-10.

As a silane coupling agent of Formula (4), for example, vinyltrimethoxysilane, vinyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-( Meth)acryloxypropylmethyldimethoxysilane, 3-(meth)acryloxypropyltrimethoxysilane, 3-(meth)acryloxypropylmethyldiethoxysilane, 3-(meth)acryloxypropyltriethoxysilane, N -2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, 3-ureidepropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane and 3-isocyanate propyltriethoxysilane is mentioned. These compounds can be used individually by 1 type or in combination of 2 or more type.

It is preferable that it is 0.1-10 mass parts with respect to 100 mass parts of total amounts of (a) component and (b) component, and, as for content of a silane coupling agent, it is more preferable that it is 0.25-5 mass parts. When the content of the silane coupling agent is 0.1 parts by mass or more, the effect of suppressing the interfacial peeling of the circuit member and the circuit connection material and the generation of bubbles tends to become larger, and when the content of the silane coupling agent is 10 parts by mass or less, the adhesive composition tend to have a longer uptime.

The adhesive composition which concerns on this embodiment may contain (d) electroconductive particle further. The adhesive composition containing electroconductive particle can be used especially preferably as an anisotropically conductive adhesive.

As electroconductive particle, metal particles, such as Au, Ag, Pd, Ni, Cu, and solder, carbon particle, etc. are mentioned, for example. In addition, the electroconductive particle may be a composite particle which has a nuclide particle containing non-conductive material, such as glass, ceramic, plastic, and a conductive layer, such as a metal, metal particle, carbon, which coat|covers the said nuclide particle. A metal particle may be a particle|grain which has a copper particle and the silver layer which coat|covers this copper particle. The nuclide particles of the composite particles are preferably plastic particles.

Since the composite particle which uses the said plastic particle as a nuclide particle has the deformability which deform|transforms by heating and pressurization, when bonding circuit members together, the contact area of the circuit electrode and electroconductive particle which the said circuit member has can be increased. Therefore, according to the adhesive composition containing these composite grain|particles as electroconductive particle, the connection body further excellent from a viewpoint of connection reliability is obtained.

The adhesive composition may contain the said electroconductive particle, the insulation coating electroconductive particle which has the insulating layer which coat|covers at least one part of the surface, or insulating particle|grains. The insulating layer can be provided by methods, such as hybridization. The insulating layer or insulating particles are formed of an insulating material such as a polymer resin. By using such insulating coating electroconductive particle, it becomes difficult to generate|occur|produce the short circuit by adjacent electroconductive particle.

It is preferable that the average particle diameter of electroconductive particle is 1-18 micrometers from a viewpoint of obtaining favorable dispersibility and electroconductivity.

It is preferable that content of electroconductive particle is 0.1-30 volume% on the basis of the total volume of adhesive composition, It is more preferable that it is 0.1-10 volume%, It is more preferable that it is 0.5-7.5 volume%. There exists a tendency for electroconductivity to improve that content of electroconductive particle is 0.1 volume% or more. There exists a tendency for it to become difficult to generate|occur|produce the short circuit between circuit electrodes as content of electroconductive particle is 30 volume% or less. Content (vol%) of electroconductive particle is determined based on the volume in 23 degreeC of each component which comprises the adhesive composition before hardening. The volume of each component can be calculated|required by converting mass into volume using specific gravity. Without dissolving or swelling the component whose volume is to be measured, an appropriate solvent (water, alcohol, etc.) that wets the component well is placed in a measuring cylinder, etc. It can also be found as a volume.

The adhesive composition may contain insulating organic or inorganic microparticles|fine-particles other than electroconductive particle. As the inorganic fine particles, for example, in addition to metal oxide fine particles such as silica fine particles, alumina fine particles, silica-alumina fine particles, titania fine particles and zirconia fine particles, nitride fine particles and the like. As organic microparticles|fine-particles, silicone microparticles|fine-particles, methacrylate-butadiene-styrene microparticles|fine-particles, acryl- silicone microparticles|fine-particles, polyamide microparticles|fine-particles, polyimide microparticles|fine-particles, etc. are mentioned, for example. These microparticles|fine-particles may have a uniform structure, and may have a core-shell type structure.

It is preferable that it is 5-30 mass parts with respect to 100 mass parts of total amounts of (a) component and (b) component, and, as for content of organic microparticles|fine-particles and inorganic microparticles|fine-particles, it is more preferable that it is 7.5-20 mass parts. When the content of the organic fine particles and the inorganic fine particles is 5 parts by mass or more, it tends to be relatively easy to maintain the electrical connection between the opposite electrodes, and when it is 30 parts by mass or less, the fluidity of the adhesive composition tends to be improved.

The adhesive composition may contain various additives.

When the adhesive composition according to the present embodiment is liquid at normal temperature (25°C), it can be used as a paste-like adhesive. When the adhesive composition is solid at room temperature, it may be heated and used, or it may be used after being made into a paste by adding a solvent. The solvent used for the pasting is not particularly limited as long as it does not substantially have the reactivity of the adhesive composition (including additives) and can sufficiently dissolve the adhesive composition.

The adhesive composition which concerns on this embodiment can also be shape|molded into a film form, and can also be used as a film adhesive. The film-like adhesive is, for example, a solution obtained by adding a solvent or the like to the adhesive composition as needed on a releasable support such as a fluororesin film, a polyethylene terephthalate film, a release paper, or the solvent is removed. method can be obtained. The film adhesive is more convenient from the viewpoint of handling and the like.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic sectional drawing which shows one Embodiment of the film adhesive containing the adhesive composition which concerns on this embodiment. The laminated|multilayer film 100 shown in FIG. 1 is equipped with the support body 8 and the film adhesive 40 laminated|stacked on the support body 8 so that peeling was possible. The film adhesive 40 is comprised from the insulating adhesive bond layer 5 and the electroconductive particle 7 disperse|distributed in the insulating adhesive bond layer 5. As shown in FIG. The insulating adhesive layer 5 is comprised from components other than electroconductive particle in the adhesive composition mentioned above. According to this film adhesive, handling is easy, it can install to a to-be-adhered body easily, and a connection operation|work can be performed easily. The film adhesive may have a multilayer structure containing 2 or more types of layers. When the film adhesive contains conductive particles, the film adhesive can be suitably used as the anisotropic conductive film.

According to the adhesive composition and film adhesive according to the present embodiment, the adherends can be adhered to each other by using heating and pressurization together normally. Heating temperature becomes like this. Preferably it is 100-250 degreeC. The pressure is not particularly limited as long as it does not damage the adherend, but is generally preferably 0.1 to 10 MPa. It is preferable to perform these heating and pressurization in the range for 0.5 to 120 second. According to the adhesive composition and film adhesive according to the present embodiment, for example, under conditions of 140°C and about 3 MPa, it is possible to sufficiently adhere adherends to each other even when heated and pressurized for a short time for 5 seconds.

The adhesive composition and film adhesive according to the present embodiment can be used as adhesives with different types of adherends having different coefficients of thermal expansion. Specifically, the adhesive composition and film adhesive according to the present embodiment, in addition to the anisotropic conductive adhesive, as a circuit connection material such as a silver paste and a silver film, an elastomer for CSP, an underfill material for CSP, a semiconductor element adhesive material such as an LOC tape can be used

Hereinafter, about an example in which the film adhesive according to the present embodiment is used as an anisotropic conductive film, and circuit members having circuit boards and circuit electrodes formed on the main surfaces of the circuit board are connected as adherends, and a connection body is manufactured. Explain.

Fig. 2 is a schematic cross-sectional view showing an embodiment of a connecting body in which the adhesive composition according to the present embodiment includes a connecting member including a cured product. The connection body 1 shown in FIG. 2 is provided with the 1st circuit member 20 and the 2nd circuit member 30 which are opposingly arranged. Between the first circuit member 20 and the second circuit member 30 , a connection member 10 for bonding and connecting them is provided.

The first circuit member 20 includes a first circuit board 21 and a first circuit electrode 22 formed on a main surface 21a of the first circuit board 21 . An insulating layer may be formed on the main surface 21a of the first circuit board 21 .

The second circuit member 30 includes a second circuit board 31 and a second circuit electrode 32 formed on a main surface 31a of the second circuit board 31 . An insulating layer may also be formed on the main surface 31a of the second circuit board 31 .

The first circuit member 20 and the second circuit member 30 are not particularly limited as long as they have circuit electrodes that require electrical connection. As the first circuit board 21 and the second circuit board 31, for example, a substrate made of an inorganic material such as a semiconductor, glass, or ceramic, a substrate made of an organic material such as polyimide or polycarbonate, glass/epoxy, etc. and a substrate containing an inorganic material and an organic material. The first circuit board 21 may be a glass substrate, and the second circuit board 31 may be a flexible substrate (preferably, a resin film such as a polyimide film).

Specific examples of the circuit member to be connected include a glass or plastic substrate, a printed wiring board, a ceramic wiring board, a flexible wiring board, a semiconductor silicon chip, etc. on which an electrode such as an ITO (indium tin oxide) film is formed, which is used in a liquid crystal display. . These are used in combination as needed. Thus, according to the adhesive composition which concerns on this embodiment, in addition to the member which has a surface formed from organic materials, such as a printed wiring board and a polyimide film, metals, such as copper and aluminum, ITO, silicon nitride (SiN _x ), silicon dioxide (SiO) ₂ ), such as a member having a surface formed of an inorganic material, etc., can be used for bonding circuit members having a wide variety of surface states.

For example, when one circuit member is a solar cell having electrodes such as a finger electrode and a bus bar electrode, and the other circuit member is a tab wire, a connection body obtained by connecting these is a solar cell, a tab wire and these It is a solar cell module provided with the connection member (hardened|cured material of adhesive composition) to adhere|attach.

As for the connection member 10, the adhesive composition which concerns on this embodiment contains the hardened|cured material. The connection member 10 contains the insulating layer 11 and the electroconductive particle 7 disperse|distributed in the insulating layer 11. As shown in FIG. The electroconductive particle 7 is arrange|positioned not only between the 1st circuit electrode 22 and the 2nd circuit electrode 32 which oppose but also between the main surfaces 21a, 31a. Since the 1st circuit electrode 22 and the 2nd circuit electrode 32 are electrically connected via the electroconductive particle 7, the connection resistance between the 1st circuit electrode 22 and the 2nd circuit electrode 32. This is sufficiently reduced. Therefore, the current flow between the first circuit electrode 22 and the second circuit electrode 32 can be made smooth, and the function of the circuit can be sufficiently exhibited. When a connection member does not contain electroconductive particle, when the 1st circuit electrode 22 and the 2nd circuit electrode 32 contact, they are electrically connected.

Since the connecting member 10 is formed of the cured product of the adhesive composition according to the present embodiment, the adhesive strength of the connecting member 10 to the first circuit member 20 and the second circuit member 30 is high enough Therefore, also after a reliability test (high-temperature, high-humidity test), the fall of adhesive strength and the increase of connection resistance can fully be suppressed.

The connection body 1 includes, for example, a process of arranging a pair of circuit members facing each other having a circuit electrode, with a film adhesive containing an adhesive composition interposed therebetween; a pair of circuit members and a film adhesive can be produced by a method comprising a step (this connection step) of bonding a pair of circuit members through a cured product of an adhesive composition by heating and curing while pressing in the thickness direction of the film adhesive.

Fig. 3 is a process diagram showing an embodiment in which a connector is manufactured with the adhesive composition according to the present embodiment by a schematic cross-sectional view. As shown in FIG.3(a), the film adhesive 40 is mounted on the main surface on the side of the 1st circuit electrode 22 of the 1st circuit member 20. As shown in FIG. When the film adhesive 40 is provided on the above-described support, in the direction in which the film adhesive 40 is positioned on the first circuit member 20 side, the laminate of the film adhesive and the support is loaded onto the circuit member. do. Since the film adhesive 40 is in the form of a film, handling is easy. For this reason, the film adhesive 40 can be easily interposed between the 1st circuit member 20 and the 2nd circuit member 30, and the 1st circuit member 20 and the 2nd circuit member 30 are Connection work can be performed easily.

The film adhesive 40 is the above-mentioned adhesive composition (circuit connection material) formed in the form of a film, and has the electroconductive particle 7 and the insulating adhesive bond layer 5. FIG. Even when an adhesive composition does not contain electroconductive particle, it can be used as a circuit connection material for electrically connecting by connecting circuit electrodes directly. The circuit connection material which does not contain electroconductive particle may be called NCF(Non-Conductive-FILM) or NCP(Non-Conductive-Paste). When the adhesive composition has conductive particles, the circuit connection material using the adhesive composition is sometimes called an ACF (Anisotropic Conductive FILM) or ACP (Anisotropic Conductive Paste).

It is preferable that the thickness of the film adhesive 40 is 10-50 micrometers. If the thickness of the film adhesive 40 is 10 micrometers or more, there exists a tendency for it to become easy to fill between the 1st circuit electrode 22 and the 2nd circuit electrode 32 with an adhesive agent. If the thickness of the film adhesive is 50 µm or less, the adhesive composition between the first circuit electrode 22 and the second circuit electrode 32 can be sufficiently excluded, and the first circuit electrode 22 and the second circuit electrode 32 ) can be easily secured.

In the thickness direction of the film adhesive 40, by applying pressures A and B as shown in Fig. 3A, the film adhesive 40 is temporarily connected to the first circuit member 20 (Fig. See (b) of 3). At this time, you may pressurize while heating. However, the heating temperature is set to a temperature sufficiently lower than the temperature at which the adhesive composition in the film adhesive 40 is not cured, that is, the temperature at which the radical polymerization initiator rapidly generates radicals.

Subsequently, as shown in FIG. 3C , the second circuit member 30 is placed on the film adhesive 40 in the direction in which the second circuit electrode is positioned on the first circuit member 20 side. load up When the film adhesive 40 is provided on the support body, the 2nd circuit member 30 is mounted on the film adhesive 40 after peeling a support body.

Then, the film adhesive 40 is heated, applying pressures A and B in the thickness direction. The heating temperature at this time is set to the temperature at which a radical polymerization initiator fully generate|occur|produces a radical. Thereby, radicals generate|occur|produce from a radical polymerization initiator, and superposition|polymerization of a radically polymerizable compound is started. By this connection, the connection body shown in FIG. 2 is obtained. By heating the film adhesive 40 , the insulating adhesive is cured to form the insulating layer 11 in a state where the distance between the first circuit electrode 22 and the second circuit electrode 32 is sufficiently small. As a result, the first circuit member 20 and the second circuit member 30 are firmly connected through the connecting member 10 including the insulating layer 11 .

This connection is preferably performed under the conditions of a heating temperature of 100 to 250°C, a pressure of 0.1 to 10 MPa, and a pressurization time of 0.5 to 120 seconds. These conditions are suitably selected by the use to be used, adhesive composition, and a circuit member. According to the adhesive composition according to the present embodiment, it is possible to obtain a connector having sufficient reliability even under low-temperature conditions such as 140°C or less. After this connection, if necessary, post-curing may be performed.

Example

Hereinafter, the present invention will be described in more detail by way of Examples and Comparative Examples. However, the present invention is not limited to the following examples.

<Synthesis of Urethane Acrylate>

To a 2-liter four-neck flask equipped with a thermometer, a stirrer, an inert gas inlet and a reflux condenser, 4000 parts by mass of polycarbonate diol (manufactured by Aldrich, number average molecular weight Mn=2000) and 2-hydroxyethyl acrylate 238 mass parts, 0.49 mass parts of hydroquinone monomethyl ether, and 4.9 mass parts of tin catalysts were thrown in, and the reaction liquid was prepared. With respect to the reaction liquid heated at 70 degreeC, 666 mass parts of isophorone diisocyanate (IPDI) was dripped uniformly over 3 hours, and it was made to react. After completion of the dropwise addition, the reaction was continued for 15 hours, and the reaction was terminated when it was confirmed that the NCO content had become 0.2% by mass with a potentiometric automatic titration device (trade name AT-510, manufactured by Kyoto Denshi Kogyo Co., Ltd.), and urethane acrylate got As a result of analysis by GPC (gel permeation chromatography), the weight average molecular weight of the urethane acrylate was 8500 (standard polystyrene conversion value). In addition, the analysis by GPC was performed under the conditions shown in Table 1 below.

<Production of conductive particles>

A nickel layer having a thickness of 0.2 µm was formed on the surface of the polystyrene particles, and a gold layer having a thickness of 0.04 µm was formed on the outside of these nickel layers. In this way, the electroconductive particle with an average particle diameter of 4 micrometers was produced.

<Production of film adhesive>

The raw materials shown in Table 2 were mixed by the mass ratio shown in Table 2. The said electroconductive particle was disperse|distributed there in the ratio of 1.5 volume%, and the coating liquid for forming a film adhesive was obtained. This coating liquid was apply|coated to a 50-micrometer-thick polyethylene terephthalate (PET) film using the coating apparatus. The coating film was dried with hot air at 70°C for 10 minutes to form a film adhesive having a thickness of 18 µm.

Each numerical value shown in Table 2 represents the mass part of solid content. In addition, the specific substance of each raw material shown in Table 2 is as showing below.

· Urethane acrylate: synthesized as described above;

-Radically polymerizable compound A: methacryloyloxyethyl isocyanate (molecular weight 155.15, purity 99%);

-Radically polymerizable compound B: methacrylic acid 2-(0-[1'-methylpropylideneamino]carboxyamino)ethyl (molecular weight 240.00, purity 99%);

-Radically polymerizable compound C: monofunctional acrylate compound (trade name Arix CHA, Toagosei Co., Ltd. make: cyclohexyl acrylate);

-Phenoxy resin: a 40 mass % solution prepared by dissolving 40 g of PKHC (manufactured by Union Carbide, trade name: average molecular weight 45000) in 60 g of methyl ethyl ketone;

-Phosphate ester: 2-methacryloyloxyethyl acid phosphate (trade name Light Ester P-2M, manufactured by Kyoeisha Chemical Co., Ltd.);

·Silane coupling agent: 3-methacryloxypropyltrimethoxysilane (trade name KBM-503, manufactured by Shin-Etsu Chemical Co., Ltd.);

Peroxide: lauroyl peroxide (trade name peroyl L, manufactured by Nichiyu Corporation: molecular weight 398.6);

-Inorganic fine particles: A 10 mass % dispersion liquid prepared by dispersing 10 g of silica particles (trade name R104, manufactured by Nippon Aerosil Co., Ltd.) in a mixed solvent of 45 g of toluene and 45 g of ethyl acetate.

<Production of connector>

A flexible circuit board (FPC) having 2200 copper circuits with a line width of 75 µm, a pitch of 150 µm and a thickness of 18 µm using the above film adhesive as a circuit connection material, a glass substrate and 0.2 µm thick formed on the glass substrate An ITO substrate having a thin layer of indium oxide (ITO) (thickness of 1.1 mm, surface resistance of 20 Ω/□) was connected. Connection was performed by heating and pressurization for 5 seconds at 140 degreeC and 3 MPa using the thermocompression-bonding apparatus (heating method: constant heat type, Toray Engineering Co., Ltd. make). Thereby, the connection body in which the FPC and the ITO board|substrate were connected by the hardened|cured material of the film adhesive over width 1.5mm was produced.

<Measurement of connection resistance and adhesive strength>

The resistance value (connection resistance) between adjacent circuits of the obtained connection body was measured with a multimeter. The resistance value was expressed as the average of 37 resistance points between adjacent circuits. In addition, the adhesive strength of this connection body was measured by the 90 degree peeling method according to JIS-Z0237. As a measuring apparatus of adhesive strength, Tensilon UTM-4 (The Toyo Baldwin Co., Ltd. make, brand name, peeling strength 50 mm/min, 25 degreeC) was used. Connection resistance and adhesive strength were measured about the connection body after hold|maintaining for 250 hours in the constant temperature and humidity chamber of 85 degreeC and 85 %RH immediately after connection and. Table 3 shows the evaluation results.

<Evaluation of available time>

Using the above film adhesive treated at 40°C for 3 days as a circuit connection material, a connection body was produced by the method similar to the above, and connection resistance and adhesive strength were measured by the above method. Table 3 shows the evaluation results.

According to the film adhesive of each example, good connection resistance (5Ω or less) and adhesive strength (6N/ cm or more) was confirmed. In particular, in Example 5 using a film adhesive containing a radically polymerizable compound having a structure in which an isocyanate group is generated by heating, the adhesive strength after treatment at 40° C. for 3 days is more excellent, and the pot life can be further improved. It was confirmed that there was

On the other hand, in the case of the film adhesive of Comparative Example 1 which does not completely contain, as a radically polymerizable compound, a radically polymerizable compound having an isocyanate group or a radically polymerizable compound having a structure in which an isocyanate group is generated by heating, immediately after connection, high temperature In all cases after the high-humidity test and after treatment at 40°C for 3 days, it was confirmed that sufficient adhesive strength was not obtained as compared with each Example.

1: junction
5: insulating adhesive layer
7: conductive particles
8: support
10: connection member
11: Insulation layer
20: first circuit member
21: first circuit board
21a: give
22: first circuit electrode
30: second circuit member
31: second circuit board
31a: give
32: second circuit electrode
40: film adhesive
100: laminated film

Claims (5)

(a) a thermoplastic resin;
(b) a radically polymerizable compound, and
(c) radical polymerization initiator
An adhesive composition containing
The (b) radically polymerizable compound includes a radically polymerizable compound having an isocyanate group or a radically polymerizable compound having a structure in which an isocyanate group is generated by heating,
The radically polymerizable compound which has the said isocyanate group is 2-(meth)acryloyloxyethyl isocyanate, 2-(meth)acryloyloxymethyl isocyanate, 2-(meth)acryloyloxypropyl isocyanate, and 1,1- The adhesive composition which is at least 1 sort(s) selected from the group which consists of (bisacryloyloxymethyl) ethyl isocyanate. The content of the radically polymerizable compound having an isocyanate group or a radically polymerizable compound having a structure in which an isocyanate group is generated by heating is the total amount of the (a) thermoplastic resin and (b) radically polymerizable compound. The adhesive composition which is 2-12 mass parts with respect to 100 mass parts. The adhesive composition of Claim 1 or 2 which further contains (d) electroconductive particle. a first circuit member having a first circuit electrode formed on a main surface of the first circuit board;
a second circuit member having a second circuit electrode formed on a main surface of a second circuit board and disposed so that the second circuit electrode and the first circuit electrode face each other;
A connection member provided between the first circuit member and the second circuit member to electrically connect the first circuit member and the second circuit member
to provide
A connection body, wherein the connection member is a cured product of the adhesive composition according to claim 1 or 2. The connector according to claim 4, wherein one of the first circuit board and the second circuit board is a flexible board.

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