TWI763551B - Connection structure, circuit connection member, and adhesive composition - Google Patents

Abstract

The present invention provides a connection structure including: a first circuit member having a first circuit electrode; a second circuit member having a second circuit electrode; A circuit connection member in which the circuit electrode and the second circuit electrode are electrically connected to each other, and the linear thermal expansion amount L(t) of the circuit connection member at the temperature t satisfies dL( t)/dt<0 condition.

Description

Connection structure, circuit connection member, and adhesive composition

The present invention relates to a connection structure, a circuit connection member and an adhesive composition.

Conventionally, in semiconductor elements and display elements, various adhesives have been used for the purpose of bonding various circuit members in the elements to each other. In addition to adhesiveness, the adhesive is also required to have various properties such as heat resistance and reliability in a high temperature and high humidity state. In addition, printed wiring boards, organic substrates such as polyimide, metals such as titanium, copper, and aluminum, and members having various surface states such as ITO, IZO, IGZO, SiN, and SiO ₂ are used for circuit members. The material used in the adhesive needs to be molecularly designed according to the circuit components.

Recently, amorphous indium tin oxide (ITO) films, organic insulating films, etc. have been used in circuit members for the purpose of simplifying the manufacturing steps of semiconductor elements and display elements and lowering the temperature. Increase. These film surfaces are often disadvantageous for adhesion from a physical viewpoint such as less surface unevenness, or a chemical viewpoint such as low surface wettability.

On the other hand, in order to strengthen the bonding between the circuit connecting member obtained by curing the adhesive, and the circuit member, covalent bonds, hydrogen bonds, and van der Waals may occur between the circuit connecting member and the surface of the circuit member. Additives such as interactive coupling agents such as hydrophobic interactions due to force (van der Waals force) are added to the adhesive. As the coupling agent, a silane coupling agent, a coupling agent having a phosphoric acid group, a carboxyl group, or the like can be used. For example, organic functional groups such as epoxy group, acrylyl group, vinyl group, etc. are present in the resin used to constitute the circuit connection member, and have an alkoxysilane structure that generates interaction between the surface of the circuit member and the circuit connection member, phosphoric acid In the case of a coupling agent such as a base, the circuit member and the circuit connection member can be more firmly bonded (refer to Patent Documents 1 to 3). [Prior Art Literature] [Patent Literature]

Patent Document 1: Japanese Patent Laid-Open No. 2003-282637 Patent Document 2: Japanese Patent Laid-Open No. 2003-277694 Patent Document 3: Japanese Patent Laid-Open No. 2013-191625

[The problem to be solved by the invention] However, according to the study by the present inventors, when the above-mentioned additives are used, the interaction between the circuit connecting member and the circuit member is not effective depending on the type of the circuit member in the high-temperature and high-humidity environment. There is a problem that the circuit connection member is peeled off from the circuit member when it functions properly.

Therefore, the objective of this invention is to provide the connection structure which can suppress peeling of a circuit connection member from a circuit member even in a high temperature and high humidity environment, and the circuit connection member and adhesive composition used for this connection structure. [Means of Solving Problems]

In one aspect, the present invention provides a connection structure including: a first circuit member having a first circuit electrode; a second circuit member having a second circuit electrode; and a connection provided between the first circuit member and the second circuit member a circuit connecting member that electrically connects the first circuit electrode and the second circuit electrode to each other, and the linear thermal expansion amount L(t) of the circuit connecting member at temperature t satisfies at least any one of t=30℃～120℃ The condition of dL(t)/dt<0 at temperature t.

In another aspect of the present invention, there is provided a circuit connection member whose linear thermal expansion amount L(t) at temperature t satisfies dL(t)/ dt<0 condition.

The average linear thermal expansion coefficient at 30°C to 120°C of the circuit connection member is preferably 500 ppm/°C or less.

In yet another aspect, the present invention provides an adhesive composition wherein the amount of linear thermal expansion l(t) of the cured product of the adhesive composition at temperature t satisfies at least any temperature t of t=30°C to 120°C Condition of dl(t)/dt<0.

The average linear thermal expansion coefficient at 30°C to 120°C of the cured product is preferably 500 ppm/°C or less. [Effect of invention]

ADVANTAGE OF THE INVENTION According to this invention, even in a high temperature and high humidity environment, the connection structure which can suppress peeling of a circuit connection member from a circuit member, and the circuit connection member and adhesive composition used for this connection structure can be provided.

Hereinafter, embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments. "(Meth)acrylic acid" means acrylic acid or methacrylic acid, and the same applies to other similar expressions such as (meth)acrylate.

FIG. 1 is a schematic cross-sectional view showing an embodiment of a connection structure. As shown in FIG. 1 , the connection structure 1 includes a first circuit member 2 , a second circuit member 3 , and a circuit connection member 4 provided between the first circuit member 2 and the second circuit member 3 .

The first circuit member 2 includes a first substrate 5 and a first circuit electrode 6 provided on the main surface of the first substrate 5 . The second circuit member 3 includes a second substrate 7 and a second circuit electrode 8 provided on the main surface of the second substrate 7 .

The first circuit member 2 and the second circuit member 3 may be the same or different from each other, and may be chip parts such as semiconductor chips, resistor chips, and capacitor chips, and substrates such as printed circuit boards. The first substrate 5 and the second substrate 7 may be formed of inorganic substances such as semiconductors, glass, and ceramics, organic substances such as polyimide and polycarbonate, and composites such as glass/epoxy. The first circuit electrode 6 and the second circuit electrode 8 may be formed of gold, silver, tin, ruthenium, rhodium, palladium, osmium, indium, platinum, crystalline or amorphous indium tin oxide (ITO), or the like.

A plurality of circuit electrodes 6 and circuit electrodes 8 are usually provided on the circuit members 2 and the substrates 5 and 7 of the circuit members 3 (singular numbers may be used as appropriate). The first circuit member 2 and the second circuit member 3 are arranged such that at least a pair of the first circuit electrode 6 and the second circuit electrode 8 face each other.

The circuit connection member 4 contains the cured product 9 of the adhesive component and the conductive particles 10 dispersed in the cured product 9 of the adhesive component. The conductive particles 10 in the circuit connection member 4 are interposed between the first circuit electrode 6 and the second circuit electrode 8 which are opposite to each other, whereby the first circuit electrode 6 and the second circuit electrode 8 are electrically connected to each other.

The circuit connection member 4 is a circuit connection member whose temperature t°C of the circuit connection member 4 is suppressed from the viewpoint of suppressing peeling of the circuit connection member 4 from the circuit member 2 , the circuit member 3 , the circuit electrodes 6 , and the circuit electrodes 8 . The linear thermal expansion amount L(t) μm satisfies the condition of dL(t)/dt<0 at at least any one temperature t of t=30°C to 120°C.

The amount of linear thermal expansion L(t) of the circuit connection member 4 was measured using a thermomechanical analyzer, when the length of the sample was 10 mm, the width was 4 mm, the thickness was 0.1 mm, and the load was 5 gf (per 0.4 mm ² of cross-sectional area). , Under the condition that the heating rate is 5°C/min, at the temperature t=0°C～200°C, every 0.1°C is set as the temperature t°C when the linear thermal expansion amount L(0)=0 μm at the temperature t=0°C The amount of linear thermal expansion (μm) below was measured. The amount of linear thermal expansion here refers to the amount of linear thermal expansion in the longitudinal direction of the sample.

From the viewpoint of suppressing peeling of the circuit connection member 4 from the circuit member 2 , the circuit member 3 , the circuit electrodes 6 , and the circuit electrodes 8 , the amount of linear thermal expansion L(t) of the circuit connection member 4 is at t=30° C. to 120° C. At least at any temperature t, the condition of dL(t)/dt<0 is satisfied, preferably dL(t)/dt≦-0.01, more preferably dL(t)/dt≦-0.1, and more preferably dL (t)/dt≦-0.5 condition.

From the viewpoint of suppressing peeling of the circuit connection member 4 from the circuit member 2 , the circuit member 3 , the circuit electrodes 6 , and the circuit electrodes 8 , the amount of linear thermal expansion L(t) of the circuit connection member 4 is preferably t=30° C. to The condition of dL(t)/dt is satisfied at at least any temperature t of 100°C, more preferably t=30°C to 90°C, still more preferably t=30°C to 80°C.

From the viewpoint of suppressing peeling of the circuit connection member 4 from the circuit member 2 , the circuit member 3 , the circuit electrodes 6 , and the circuit electrodes 8 , the average linear thermal expansion coefficient at 30° C. to 120° C. of the circuit connection member 4 is preferably 500. ppm/°C or lower, more preferably 250 ppm/°C or lower, still more preferably 150 ppm/°C or lower.

The coefficient of linear thermal expansion (ppm/° C.) of the circuit connection member 4 is defined as the amount of linear thermal expansion (μm) per 1°C increase in temperature of the circuit connection member 4 with a length of 1 m. The average coefficient of linear thermal expansion α _L at 30°C to 120°C of the circuit connection member 4 is the amount of linear thermal expansion L(t) at t=30°C to 120°C of the circuit connection member 4 measured according to the method described above The amount of change in [unit: μm/10 mm] is converted into the linear thermal expansion amount (μm) of the length of 1 m of the circuit connecting member 4 , and the converted value is used as the average value per 1°C of temperature increase (that is, according to the following formula) to calculate. α _L ={L(t=120℃)-L(t=30℃)}×100/(120-30)

The hardened|cured material 9 and the electroconductive particle 10 of the adhesive component which comprise the circuit connection member 4 are selected so that the circuit connection member 4 may have the said characteristic. The circuit connection member 4 is obtained by hardening the adhesive composition containing the adhesive component and the electroconductive particle 10, for example. This adhesive composition is an adhesive composition that preferably cures the adhesive composition from the viewpoint of suppressing peeling of the circuit connection member 4 from the circuit member 2 , the circuit member 3 , the circuit electrodes 6 , and the circuit electrodes 8 . The linear thermal expansion l(t) of the material at temperature t satisfies the condition of dl(t)/dt<0 at at least any temperature t from t=30°C to 120°C. The cured product of the adhesive composition may be, for example, a cured product obtained by molding the adhesive composition into a film-like adhesive having a thickness of 100±20 μm and curing the film-like adhesive by heating at 180° C. for 1 hour.

The amount of linear thermal expansion l(t) of the cured product of the adhesive composition was measured using a thermomechanical analyzer when the length of the sample was 10 mm, the width was 4 mm, the thickness was 0.1 mm, and the load was 5 gf (section of the sample). Area per 0.4 mm ² ) and heating rate of 5°C/min, the linear thermal expansion l(0)=0 at t=0°C to 200°C every 0.1°C The amount of linear thermal expansion (μm) at a temperature t°C in μm was measured. The amount of linear thermal expansion here refers to the amount of linear thermal expansion in the longitudinal direction of the sample.

From the viewpoint of suppressing peeling of the cured product of the adhesive composition (circuit connecting member 4 ) from the circuit member 2 , the circuit member 3 , and the circuit electrodes 6 and 8 , the amount of linear thermal expansion l of the cured product of the adhesive composition (t) dl(t)/dt≦-0.01, more preferably dl(t)/dt≦-0.1, and still more preferably dl(t) at any temperature t ranging from t=30°C to 120°C /dt≦-0.5 condition.

From the viewpoint of suppressing peeling of the cured product of the adhesive composition (circuit connecting member 4 ) from the circuit member 2 , the circuit member 3 , and the circuit electrodes 6 and 8 , the amount of linear thermal expansion l of the cured product of the adhesive composition (t) Satisfying the above dl(t )/dt condition.

From the viewpoint of suppressing peeling of the cured product of the adhesive composition (circuit connecting member 4 ) from the circuit member 2 , the circuit member 3 , the circuit electrode 6 , and the circuit electrode 8 The average linear thermal expansion coefficient at 120°C is preferably 500 ppm/°C or less, more preferably 250 ppm/°C or less, and still more preferably 150 ppm/°C or less.

The linear thermal expansion coefficient (ppm/°C) of the cured product of the adhesive composition is defined as the amount of linear thermal expansion (μm) per 1 m in length of the cured product of the adhesive composition per 1°C increase in temperature. The average linear thermal expansion coefficient α _l at 30°C to 120°C of the cured product of the adhesive composition is the line at t=30°C to 120°C of the cured product of the adhesive composition measured according to the method described above The amount of change in thermal expansion l(t) [unit: μm/10 mm] is converted into the linear thermal expansion (μm) of the cured product of the adhesive composition with a length of 1 m, and the conversion value is used as the temperature per 1°C increase. The average value (that is, according to the following formula) is calculated. α _l ={l(t=120℃)-l(t=30℃)}×100/(120-30)

An adhesive composition having such a characteristic contains, for example, two or more resin components having mutually different glass transition temperatures (Tg), a component that tends to phase-separate from each other, a component having a skeleton that can be easily aligned, and a negative The linear thermal expansion coefficient of the filler composition, etc. As a combination of components that are likely to be phase-separated from each other, a combination of components with a large difference in molecular weight, a combination of components with a large difference in polarity between each other, and the like are exemplified. Specifically, the combination of components that are prone to phase separation may be: a combination of an acrylic resin and an epoxy resin, a combination of a urethane resin and a phenoxy resin, a combination of an acrylic rubber and a phenoxy resin, and an acrylic resin. The combination of rubber and epoxy resin, etc. As a component which has a skeleton which is easy to align, the component containing an alkyl chain, the component containing a phenyl group, etc. are mentioned. The inventors of the present invention considered that by containing the above-mentioned components in the adhesive composition, in the cured product (circuit connecting member 4 ) of the adhesive composition obtained, the reduction of microvoids due to the temperature rise, the reduction of molecular chains Realignment of filler components, etc., and shrinkage (volume phenomenon) accompanying temperature rise occurs.

In one embodiment, the adhesive composition preferably contains (a) a thermoplastic resin (hereinafter also referred to as "component (a)") and (b) a radical polymerizable compound (hereinafter also referred to as "component (b)") "), and (c) a radical polymerization initiator (hereinafter also referred to as "(c) component").

Although it does not specifically limit as (a) component, For example, a polyimide resin, a polyamide resin, a phenoxy resin, a poly(meth)acrylic resin, a polyester resin, and a polyurethane can be mentioned. One or two or more of resins, polyester urethane resins and polyvinyl butyral resins.

From the viewpoint of easily obtaining a cured product (circuit connecting member 4) of the adhesive composition having a desired amount of linear thermal expansion, the adhesive composition preferably contains two or more of the thermoplastic resins, more preferably contains two or more kinds of the thermoplastic resins. Two or more thermoplastic resins having mutually different Tg's. Examples of suitable combinations of resins include combinations of phenoxy resins and poly(meth)acrylic resins, combinations of phenoxy resins and polyester resins, and combinations of phenoxy resins and polyester urethane resins. combination of phenoxy resin and polyimide resin.

In the case where the adhesive composition contains two or more thermoplastic resins having different Tg, it is easier to obtain a cured product (circuit connecting member 4 ) of the adhesive composition having a desired amount of linear thermal expansion. The content ratio of the thermoplastic resin having a high Tg to the thermoplastic resin having a lower Tg (mass ratio: high Tg/low Tg) is preferably 90/10 to 10/90, more preferably 90/10 to 20/80 , and more preferably 90/10 to 30/70. When the adhesive composition contains three or more thermoplastic resins having different Tg, the adhesive composition is preferably such that the content ratio of the thermoplastic resin having the highest Tg and the thermoplastic resin having the lowest Tg becomes the content. contained in the manner of comparison.

The weight average molecular weight of the thermoplastic resin is preferably 5,000 or more, more preferably 10,000 or more, and is preferably 400,000 or less, more preferably 200,000 or less, and still more preferably 150,000 or less. When the weight average molecular weight of the thermoplastic resin is 5,000 or more, the adhesive force of the adhesive composition tends to improve. When the weight average molecular weight of the thermoplastic resin is 400,000 or less, the compatibility with other components is excellent, and the fluidity of the adhesive tends to be improved. The weight average molecular weight in the present invention refers to the weight average molecular weight (standard polystyrene conversion value) measured by gel permeation chromatography (Gel Permeation Chromatography, GPC).

From the viewpoint of stress relaxation and further improvement of adhesiveness, the adhesive composition may contain a rubber component as a thermoplastic resin. Examples of rubber components include silicone rubber, acrylic rubber, polyisoprene rubber, polybutadiene rubber, carboxyl-terminated polybutadiene rubber, hydroxyl-terminated polybutadiene rubber, and 1,2-polybutadiene. Rubber, carboxyl-terminated 1,2-polybutadiene rubber, hydroxyl-terminated 1,2-polybutadiene rubber, styrene-butadiene rubber, hydroxyl-terminated styrene-butadiene rubber, acrylonitrile-butadiene Rubber, carboxylated nitrile rubber, hydroxyl-terminated poly(oxypropylene) rubber, alkoxysilyl-terminated poly(oxypropylene) rubber, poly(oxytetramethylene) glycol rubber, polyolefin glycol rubber and poly- ε-caprolactone rubber. From the viewpoint of further improvement in adhesiveness, the rubber component preferably has a cyano group or a carboxyl group as a highly polar group as a side chain group or a terminal group. These rubber components may be used alone or in combination of two or more.

The rubber component may be in the form of particles. The average particle diameter of the rubber particles is preferably two times or less the average particle diameter of the conductive particles 10 , for example, 0.01 μm to 100 μm. The storage elastic modulus of the rubber particles at room temperature (25° C.) is preferably 1/2 or less of the storage elastic modulus of the conductive particles 10 and the adhesive composition at room temperature, for example, 0.1 MPa to 100 MPa. The rubber particles are preferably three-dimensionally crosslinked rubber particles from the viewpoint of being excellent in solvent resistance and being easily dispersed in the adhesive composition.

The content of the component (a) is preferably 20 parts by mass or more, more preferably 30 parts by mass or more, still more preferably 35 parts by mass or more, relative to 100 parts by mass of the total amount of the (a) component and (b) component, and further, Preferably it is 80 mass parts or less, More preferably, it is 70 mass parts or less, More preferably, it is 65 mass parts or less. When the content of the component (a) is 20 parts by mass or more, the adhesive force is further improved, and the film formability of the adhesive composition tends to be improved, and when it is 80 parts by mass or less, the fluidity of the adhesive is improved. tendency.

The component (b) is not particularly limited, and may be, for example, a compound (monomer) described below, an oligomer of the compound, or both.

The component (b) is preferably a polyfunctional (meth)acrylate compound having two or more (meth)acryloyloxy groups. As such a (meth)acrylate compound, epoxy (meth)acrylate, urethane (meth)acrylate, polyether (meth)acrylate, polyester (meth)acrylate can be mentioned. Acrylates, trimethylolpropane tri(meth)acrylates, polyethylene glycol di(meth)acrylates and other polyalkylene glycol di(meth)acrylates; dicyclopentenyl (methyl) ) acrylate, dicyclopentenyloxyethyl (meth)acrylate, neopentyl glycol di(meth)acrylate, dipentaerythritol hexa(meth)acrylate, isocyanuric acid modified difunctional ( Meth)acrylate, isocyanuric acid modified trifunctional (meth)acrylate, etc. Examples of epoxy (meth)acrylates include epoxy (meth)acrylates in which (meth)acrylic acid is added to two glycidyl groups of bisphenol fendiglycidyl ether, and epoxy (meth)acrylates in which (meth)acrylic acid is added. ) A compound in which ethylene glycol and/or propylene glycol are added to two glycidyl groups of bisphenol fendiglycidyl ether by introducing an acryloxy group. Among these (meth)acrylate compounds, it is preferable to use urethane (meth)acrylate from the viewpoint of obtaining better adhesiveness by having a urethane bond. These compounds may be used alone or in combination of two or more.

The adhesive composition may contain a monofunctional (meth)acrylate compound as a (b) component from viewpoints, such as adjustment of fluidity. 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-undecyl (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, by combining (meth)acrylic acid with epoxy resin having multiple glycidyl groups A glycidyl group-containing (meth)acrylate and (meth)acryloylmorpholine obtained by reacting one glycidyl group of a resin. These compounds may be used alone or in combination of two or more.

The adhesive composition may contain a compound having a radically polymerizable functional group such as an allyl group, a maleimide group, and a vinyl group as the component (b) from the viewpoint of improving the crosslinking rate and the like. Examples of such compounds include N-vinylimidazole, N-vinylpyridine, N-vinylpyrrolidone, N-vinylformamide, N-vinylcaprolactamide, 4,4' -Vinylidene bis(N,N-dimethylaniline), N-vinylacetamide, N,N-dimethylacrylamide, N-isopropylacrylamide and N,N-diethylamine base acrylamide.

For the purpose of improving the adhesive force, the adhesive composition preferably contains a radically polymerizable compound having a phosphate ester structure as the component (b). The radically polymerizable compound having a phosphoric acid ester structure may be, for example, a compound represented by the following formula (1), formula (2), or formula (3).

式（1）中，R¹ 表示氫原子或甲基，R² 表示(甲基)丙烯醯氧基，a及b分別獨立地表示1～8的整數。同一分子中的多個R¹ 、R² 、a及b分別可相互相同亦可不同。[hua 1]

In formula (1), R ¹ represents a hydrogen atom or a methyl group, R ² represents a (meth)acryloyloxy group, and a and b each independently represent an integer of 1 to 8. A plurality of R ¹ , R ² , a and b in the same molecule may be the same or different from each other, respectively.

式（2）中，R³ 表示(甲基)丙烯醯氧基，c及d分別獨立地表示1～8的整數。同一分子中的多個R³ 、c及d分別可相互相同亦可不同。[hua 2]

In formula (2), R ³ represents a (meth)acryloyloxy group, and c and d each independently represent an integer of 1 to 8. A plurality of R ³ , c and d in the same molecule may be the same or different from each other, respectively.

式（3）中，R⁴ 表示氫原子或甲基，R⁵ 表示(甲基)丙烯醯氧基，e及f分別獨立地表示1～8的整數。同一分子中的多個R⁴ 、R⁵ 、e及f分別可相互相同亦可不同。[hua 3]

In formula (3), R ⁴ represents a hydrogen atom or a methyl group, R ⁵ represents a (meth)acryloyloxy group, and e and f each independently represent an integer of 1 to 8. A plurality of R ⁴ , R ⁵ , e and f in the same molecule may be the same or different from each other, respectively.

Examples of the radically polymerizable compound having a phosphoric acid ester structure include acid phosphineoxyethyl (meth)acrylate, acid phosphinopropyl (meth)acrylate, and acid phosphineoxypolyoxyethylene diacrylate. Alcohol mono(meth)acrylate, acid phosphineoxy polyoxypropylene glycol mono(meth)acrylate, 2,2'-bis(meth)acrylooxydiethyl phosphate, ethylene oxide (ethylene oxide) oxide, EO) modified phosphoric acid di(meth)acrylate, phosphoric acid modified epoxy (meth)acrylate and vinyl phosphate.

The content of the component (b) in the adhesive composition is preferably 20 parts by mass or more, more preferably 30 parts by mass or more, and still more preferably 35 parts by mass relative to 100 parts by mass of the total amount of the (a) component and the (b) component It is more preferably 80 parts by mass or less, more preferably 70 parts by mass or less, and still more preferably 65 parts by mass or less. When the content of the component (b) is 20 parts by mass or more, the heat resistance of the cured product (circuit connecting member 4 ) of the adhesive composition tends to improve, and when it is 80 parts by mass or less, high temperature and high humidity can be further suppressed. The tendency of peeling of the circuit connection member 4 in the environment.

When the adhesive composition contains a radically polymerizable compound having a phosphate structure as the component (b), the radical having a phosphate structure is 100 parts by mass relative to the total amount of the components (a) and (b). The content of the polymerizable compound is preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, and is preferably 15 parts by mass or less, more preferably 10 parts by mass or less. When the content of the radically polymerizable compound having a phosphoric acid ester structure is 0.1 part by mass or more, the adhesive strength of the adhesive composition tends to be further increased, and when it is 15 parts by mass or less, it is difficult to produce the adhesive composition. The physical properties of the cured product (circuit connecting member 4 ) tend to decrease and the reliability to improve.

As the component (c), for example, it can be arbitrarily selected from compounds such as peroxides and azo compounds. From the viewpoint of being excellent in stability, reactivity, and compatibility, as the component (c), it is preferable to use a peroxide having a half-life temperature of 90°C to 175°C for 1 minute and a molecular weight of 180 to 1000. The "1-minute half-life temperature" refers to the temperature at which the half-life of the peroxide is 1 minute. "Half-life" refers to the time for the concentration of a compound to decrease to half of its initial value at a specified temperature.

The radical polymerization initiator may be, for example, one or more compounds selected from the following compounds: 1,1,3,3-tetramethylbutyl peroxyneodecanoate, bis(4-tert-butylcyclohexyl) ) Peroxydicarbonate, bis(2-ethylhexyl)peroxydicarbonate, cumyl peroxyneodecanoate, dilaurin peroxide, 1-cyclohexyl-1-methylethylneodecanoperoxide acid ester, tert-hexyl peroxyneodecanoate, tert-butyl peroxy-neodecanate, tert-butyl peroxy-neopentanoate, 1,1,3,3-tetramethylbutylperoxy -2-ethylhexanoate, 2,5-dimethyl-2,5-bis(2-ethylhexylperoxy)hexane, tertiary hexylperoxy-2-ethylhexanoate, tert-butyl peroxy-2-ethylhexanoate, tert-butyl peroxyneoheptanoate, tert-amyl peroxy-2-ethylhexanoate, di-tert-butyl peroxyhexadecanoate Hydrogen terephthalate, tert-amyl peroxy-3,5,5-trimethylhexanoate, 3-hydroxy-1,1-dimethylbutyl peroxyneodecanoate, 1, 1,3,3-Tetramethylbutylperoxy-2-ethylhexanoate, 3-pentylperoxyneodecanoate, 3-pentylperoxy-2-ethylhexanoate, 3- methylbenzyl peroxide, 4-methylbenzyl peroxide, bis(3-methylbenzyl) peroxide, dibenzyl peroxide, bis(4-methylbenzyl) peroxide methylbenzyl) peroxide, 2,2'-azobis-2,4-dimethylvaleronitrile, 1,1'-azobis(1-acetoxy-1-phenyl) ethane), 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), dimethyl-2,2'-azobisisobutyronitrile, 4 ,4'-azobis(4-cyanovaleric acid), 1,1'-azobis(1-cyclohexanecarbonitrile), tert-hexyl peroxyisopropyl monocarbonate, tert-butyl Peroxymaleic acid, tert-butylperoxy-3,5,5-trimethylhexanoate, tert-butylperoxylaurate, 2,5-dimethyl-2,5-di (3-methylbenzylperoxy)hexane, tert-butylperoxy-2-ethylhexyl monocarbonate, tert-hexyl peroxybenzoate, 2,5-dimethyl-2 , 5-bis(benzyl peroxy) hexane, tert-butyl peroxybenzoate, dibutyl peroxytrimethyl adipate, tert-amyl peroxy n-octanoate, Third amyl peroxyisonononanoate and third amyl peroxybenzoate.

From the viewpoint of suppressing corrosion of the circuit electrodes 6 and 8, the content of chloride ions or organic acids in the radical polymerization initiator is preferably 5000 ppm or less, and it is more preferable to use organic acids generated after decomposition. Less free radical polymerization initiator. From the viewpoint of improving the stability of the adhesive composition, it is preferable to start the radical polymerization with a mass retention rate of 20 mass % or more after being left in the atmosphere at room temperature (25° C.) and atmospheric pressure for 24 hours. agent.

The content of the component (c) in the adhesive composition is preferably 1 part by mass or more, more preferably 2.5 parts by mass or more, relative to 100 parts by mass of the total amount of the (a) component and the (b) component, and more preferably It is 15 mass parts or less, More preferably, it is 10 mass parts or less.

In another embodiment, the adhesive composition preferably contains: (a) thermoplastic resin, (d) epoxy resin (hereinafter also referred to as "(d) component"), and (e) hardener (hereinafter also referred to as "component") "(e) Ingredient"). The (a) component in this embodiment is the same component as the (a) component demonstrated in the said embodiment.

(d) The epoxy resin is a resin having at least one epoxy group in the molecule. As epoxy resins, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, phenol novolak type epoxy resin, cresol novolak type epoxy resin, bisphenol novolak type epoxy resin, Phenol A novolak epoxy resin, bisphenol F novolak epoxy resin, alicyclic epoxy resin, glycidyl ester epoxy resin, glycidylamine epoxy resin, hydantoin epoxy resin , Isocyanurate epoxy resin, aliphatic chain epoxy resin, etc. (d) The epoxy resin may be a halogenated epoxy resin in which the epoxy resin is halogenated, or a hydrogenated epoxy resin in which the epoxy resin is hydrogenated. These epoxy resins, halogenated epoxy resins, and hydrogenated epoxy resins may be used alone or in combination of two or more.

The content of the component (d) in the adhesive composition is preferably 10 parts by mass or more, more preferably 20 parts by mass or more, and still more preferably 30 parts by mass relative to 100 parts by mass of the total amount of the (a) component and the (d) component It is more preferably 90 parts by mass or less, more preferably 80 parts by mass or less, and still more preferably 70 parts by mass or less. When the content of the component (d) is 10 parts by mass or more, more favorable adhesiveness tends to be obtained, and when it is 90 parts by mass or less, the viscosity tends to be small and workability becomes good.

The (e) hardener (also referred to as "epoxy polymerization initiator" or "latent hardener") may be a hardener capable of hardening the (d) epoxy resin. As a hardener, an anion polymerizable catalyst type hardener, a cation polymerizable catalyst type hardener, an addition polymerization type hardener, etc. are mentioned. These can be used alone or in combination of two or more. The (e) hardener is preferably an anionic polymerizable or cationically polymerizable catalyst-type hardener from the viewpoint of being excellent in rapid hardening properties and without considering the chemical equivalent.

Examples of the anionically polymerizable or cationically polymerizable catalyst-type curing agent include imidazole-based curing agents, hydrazine-based curing agents, boron trifluoride-amine complexes, onium salts such as perylene salts and diazonium salts, Aminimide, diaminomaleonitrile, melamine and its derivatives, polyamine salts, dicyandiamine, etc., and modified products of these can also be used.

In the case of using a compound having a tertiary amine group, an imidazole compound, etc. as an anionic polymerizable catalyst-type hardener, the epoxy resin is heated at a temperature of about 160°C to 200°C for several tens of seconds to several hours. and hardened. Therefore, the pot life of the adhesive composition can be prolonged longer. As a cationically polymerizable catalyst-type hardener, for example, photosensitive onium salts (aromatic diazonium salts, aromatic peronium salts, etc.) that harden epoxy resins by energy ray irradiation can be preferably used. As a cationic polymerizable catalyst type hardener which is activated by heating and hardens an epoxy resin, aliphatic periconium salts etc. are mentioned. These anionic polymerizable or cationic polymerizable catalyst-type hardeners can be preferably used in terms of having rapid hardening properties.

As an addition polymerization type hardening|curing agent, a polyamine, a polythiol, a polyphenol, an acid anhydride, etc. are mentioned.

In terms of obtaining a longer usable time, these can be preferably coated with polymer compounds such as polyurethane and polyester, metal films such as nickel and copper, and inorganic substances such as calcium silicate. Hardener (latent hardener) and microencapsulated hardener.

The content of the component (e) in the adhesive composition is preferably 20 parts by mass or more, more preferably 30 parts by mass or more, relative to 100 parts by mass of the total amount of the (a) component and (d) component, and is preferably 80 parts by mass or less, more preferably 70 parts by mass or less.

As electroconductive particle 10, metal particles, such as Au, Ag, Ni, Cu, and solder, and electroconductive particle, such as electroconductive carbon particle, are mentioned. The electroconductive particle 10 may be a coated electroconductive particle, which includes: a core including non-conductive glass, ceramic, plastic, etc. particles; and a layer made of the metal, metal particles, and electroconductive carbon particles covering the core Wait. In the case where the conductive particles 10 are coated conductive particles or metal particles melted by heat (hot-melt metal particles), the conductive particles 10 are deformed by heating and pressurization at the time of circuit connection. 6. The height of the circuit electrode 8 varies, and the contact area between the conductive particles 10 and the circuit electrode 6 and the circuit electrode 8 also increases, so that good reliability can be obtained. In particular, when the preparation amount of the conductive particles 10 increases, the short circuit between the conductive particles 10 is prevented, and the adjacent first circuit electrodes 6 and between the first circuit electrodes 6 or the second circuit electrodes 8 and the second circuit are lifted up. From the viewpoint of the insulating properties between the electrodes 8, the conductive particles 10 may be insulating coating conductive including the conductive particles and the insulating coating layer formed of an insulating material such as a polymer resin covering the surface of the conductive particles. particle. These electroconductive particles, coating electroconductive particles, and insulating-coated electroconductive particles may be used alone or in combination of two or more.

From the viewpoint of being excellent in dispersibility and conductivity, the average particle diameter of the conductive particles 10 is preferably 1 μm to 50 μm. The content of the conductive particles is preferably 0.1% by volume or more, preferably 30% by volume or less, and more preferably 10% by volume or less, based on the total amount of the adhesive composition. When the content is 0.1 vol % or more, the conductivity tends to be further improved, and when it is 30 vol % or less, the adjacent first circuit electrodes 6 and between the first circuit electrodes 6 or the second circuit electrodes 8 and the second circuit electrodes 8 and the Tendency to short circuit between two circuit electrodes 8 . Content of the electroconductive particle 10 is determined based on the volume of each component of the adhesive composition (before hardening) in 23 degreeC. For the volume of each component, for example, a specific gravity can be used, and a value converted into a volume from a weight can be used. In addition, for example, a suitable solvent (water, alcohol, etc.) that sufficiently wets the component without dissolving or swelling the component may be added to a measuring cylinder or the like, and the component may be charged and the increased volume may be used as the volume. and ask for.

In addition to (a) component, (b) component, (c) component and the conductive particles 10 or (a) component, (d) component, (e) component and the conductive particles 10, the adhesive composition may further contain Phenol resin, melamine resin and other resins, fillers (fillers), softeners, hardening accelerators, anti-aging agents, colorants, flame retardants, thixotropic agents, coupling agents and other adhesion promoters, thickeners, leveling agents agents, weather resistance enhancers, isocyanate compounds, etc.

The filler (filler) may be composed of silicon, calcium, zirconium, titanium, aluminum, carbon, bismuth, cobalt, copper, iron, indium, manganese, tin, yttrium, zinc, etc., or compounds containing these, organic compounds, etc. particle of. The average particle diameter of the particles is preferably 1/2 or less of the average particle diameter of the conductive particles 10 , for example, 0.005 μm to 25 μm. When the adhesive composition contains non-conductive particles (for example, the rubber particles), the average particle diameter of the particles used as the filler may be equal to or less than the average particle diameter of the non-conductive particles.

From the viewpoint of further improving electrical properties such as the connection reliability between the circuit electrodes 6 and the circuit electrodes 8 by the cured product (circuit connecting member 4 ) of the adhesive composition having a desired amount of linear thermal expansion, the filler is relatively A filler having a negative average coefficient of linear thermal expansion at 30°C to 120°C is preferred. As a filler whose average linear thermal expansion coefficient in 30 degreeC - 120 degreeC is negative, the particle|grain which consists of a zirconium type compound is mentioned, for example.

The content of the filler is preferably 5 parts by mass or more, and preferably 60 parts by mass or less, relative to 100 parts by mass of the adhesive composition. When the content is 60 parts by mass or less, the effect of improving connection reliability tends to be more sufficiently obtained, and when it is 5 parts by mass or more, the effect of adding a filler tends to be sufficiently obtained.

The coupling agent may be, for example, a silane coupling agent. By using a coupling agent such as a silane coupling agent, the adhesive force of the adhesive composition can be further improved. Examples of the silane coupling agent include vinyltrimethoxysilane, vinyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, and 3-glycidoxypropylmethyldiethoxy Silane, 3-(meth)acryloyloxypropylmethyldimethoxysilane, 3-(meth)acryloyloxypropyltrimethoxysilane, 3-(meth)acryloyloxy Propylmethyldiethoxysilane, 3-(meth)acryloyloxypropyltriethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxy Silane, N-phenyl-3-aminopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-isocyanatopropyltriethoxy Silane, and their condensates.

The content of the coupling agent is preferably 0.1 part by mass or more, more preferably 0.25 part by mass or more, with respect to 100 parts by mass of the adhesive components (for example, (a) components to (e) components) of the adhesive composition, and more preferably 10 parts by mass or less, more preferably 5 parts by mass or less. When the content of the coupling agent is 0.1 parts by mass or more, the occurrence of peeling between the circuit member and the circuit connecting member tends to be further suppressed, and when the content of the coupling agent is 10 parts by mass or less, the usable time of the adhesive composition is limited Tendency to grow.

When the adhesive composition is liquid at, for example, 15°C to 25°C, it can be used as a paste adhesive composition. When the adhesive composition is solid at room temperature (25° C.), it can be used as a paste adhesive composition by heating, or can be used as a paste adhesive composition by dissolving in a solvent. The solvent is not particularly limited as long as it has no reactivity with the components contained in the adhesive composition, and the components contained in the adhesive composition exhibit sufficient solubility, and the boiling point under atmospheric pressure can be preferably used: 50℃～150℃ solvent. When the boiling point is 50° C. or higher, volatilization of the solvent at room temperature (25° C.) can be suppressed, and use in an open system becomes easy. When the boiling point is 150° C. or lower, the solvent is easily volatilized after the adhesive composition is applied to the circuit member 2 and the circuit member 3 , and the reliability after bonding can be ensured.

The adhesive composition can also be used as a film adhesive. The adhesive composition is, for example, a solution obtained by adding a solvent or the like to the adhesive composition as needed, and is applied to a releasable substrate such as a fluororesin film, a polyethylene terephthalate film, a release paper, or the like, or a A base material such as a nonwoven fabric is impregnated with the solution and placed on a releasable base material, and thereafter, the solvent and the like are removed to form a film. From the viewpoint of workability and the like, a film adhesive is preferably used.

The adhesive composition can be used as a circuit connection material represented by anisotropic conductive adhesive, silver paste, silver film, etc., elastomer for chip scale packaging (CSP), underfill for CSP, communication Line of communication (LOC) tapes and the like are representative of the semiconductor element bonding material.

The connection structure 1 can be obtained, for example, by arranging the first circuit member 2 and the second circuit member 3 so that the first circuit electrode 6 and the second circuit electrode 8 are opposed to each other, and interposing the film-like adhesive between the first circuit member 2 and the second circuit member 3 . Between the first circuit member 2 and the second circuit member 3, these are heated and pressurized to electrically connect the first circuit electrode 6 and the second circuit electrode 8 to each other.

The heating temperature during heating is not particularly limited, but is preferably 50°C to 250°C. The pressure during pressurization is not particularly limited as long as it is a range that does not damage the adherends (circuit member 2 , circuit member 3 ), but is preferably 0.1 MPa to 10 MPa. Heating and pressurization are preferably performed for 0.5 seconds to 3 hours.

When the circuit member 2 and the circuit member 3 are connected to each other, from the viewpoint of connecting at a lower temperature and in a short time, light irradiation can be performed simultaneously with heating and pressing. It is preferable to use irradiation light of the wavelength range of 150 nm - 750 nm for light irradiation. Light irradiation can be performed at an irradiation amount of 0.1 J/cm ² to 10 J/cm ² using, for example, a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high pressure mercury lamp, a xenon lamp, or a metal halide lamp.

The cured product (circuit connecting member 4 ) of the adhesive composition described above is, for example, as indicated by L1 in FIG. 2 , at a temperature of t=30°C to 120°C, where dl(t)/dt<0 (dL (t)/dt<0) of a t-like cured product (circuit connecting member), the thermal expansion amount of the circuit connecting member 4 itself can be reduced due to the temperature rise, and there is a possibility that the circuit connecting member 4 and the substrate 5 and the substrate 7 The interface stress (stress to peel off the circuit connecting member 4 from the substrate 5 , the substrate 7 , and the circuit electrode 6 and the circuit electrode 8 ) generated at the interface between the circuit electrode 6 and the circuit electrode 8 is reduced.

On the other hand, the cured product (circuit connection member) of the conventional adhesive composition is, for example, as shown by L2 in FIG. 2 , at a temperature of t=30°C to 120°C, dl(t)/dt≧0 ( dL(t)/dt≧0) is a cured product (circuit connecting member) of the adhesive composition, so the circuit connecting member 4 itself is likely to thermally expand as the temperature rises, and the circuit connecting member 4 and the substrate 5 and the substrate 7 And a large peeling interface stress is generated in the interface between the circuit electrode 6 and the circuit electrode 8 .

Therefore, compared with the cured product (circuit connecting member) of the conventional adhesive composition, the cured product (circuit connecting member 4 ) of the adhesive composition of the present embodiment is even in the case of being placed in a high temperature and high humidity environment Also, peeling of the circuit connection member 4 from the substrate 5 , the substrate 7 , the circuit electrode 6 , and the circuit electrode 8 can be suppressed. Such an effect can also be exhibited in the case of using circuit electrodes formed of amorphous ITO or the like, which is unfavorable for adhesion, as the circuit electrodes 6 and 8 . [Example]

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

<Synthesis of polyurethane resin> Into a separable flask equipped with a reflux cooler, a thermometer, and a stirrer, 1,000 parts by mass of polypropylene glycol (number average molecular weight: 2,000) as a diol having an ether bond and 4,000 parts by mass of methyl ethyl ketone as a solvent were added, Stir at 40°C for 30 minutes. After raising the temperature of the solution to 70°C, 0.127 parts by mass of dibutyltin laurate was added as a catalyst. Next, a solution prepared by dissolving 125 parts by mass of 4,4′-diphenylmethane diisocyanate in 125 parts by mass of methyl ethyl ketone was added dropwise to this solution over 1 hour. Then, stirring was continued at 70 degreeC until the absorption peak derived from the NCO group was not observed by the infrared spectrophotometer, and the methyl ethyl ketone solution of the polyurethane resin was obtained. And the amount of methyl ethyl ketone was adjusted so that the solid content concentration (concentration of polyurethane resin) of this solution might become 30 mass %.

The glass transition temperature (Tg) of the obtained polyurethane resin was -20 degreeC. The glass transition temperature (Tg) was measured using a thermomechanical analyzer.

The weight average molecular weight of the obtained polyurethane resin was 320,000. The weight average molecular weight is a standard polystyrene conversion value measured by gel permeation chromatography (GPC). The analysis conditions of GPC are shown in Table 1 below. [Table 1] device GPC-8020 (manufactured by Tosoh Corporation) Detector RI-8020 (manufactured by Tosoh Corporation) pipe string Gelpack GL-A-160-S + GL-A150-SG2000Hhr (manufactured by Hitachi Chemical Co., Ltd.) Sample concentration 120 mg/3 ml solvent tetrahydrofuran Injection volume 60 μl pressure 2.94×10 ⁶ Pa flow 1.00 ml/min

<Synthesis of urethane acrylate> To a 2 L four-necked flask equipped with a thermometer, a stirrer, an inert gas inlet, and a reflux cooler, 4000 parts by mass of polycarbonate diol (manufactured by Aldrich, number average molecular weight: 2000), 238 parts by mass of 2-hydroxyethyl acrylate, 0.49 parts by mass of hydroquinone monomethyl ether, and 4.9 parts by mass of a tin-based catalyst were prepared to prepare a reaction solution. To the reaction liquid heated to 70 degreeC, 666 mass parts of isophorone diisocyanate (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 the content of the NCO group was confirmed to be 0.2 mass % or less using a potential difference automatic titrator (product name AT-510, manufactured by Kyoto Electronics Co., Ltd.), and an amine was obtained. carbamate acrylate. The weight average molecular weight of the urethane acrylate was 8500. In addition, the weight average molecular weight of urethane acrylate is measured similarly to the weight average molecular weight of the said polyurethane resin.

<Preparation of film adhesive> The components shown below were mixed at the mass ratios shown in Tables 2 and 3 to obtain an adhesive composition.

(thermoplastic resin) A1: Phenoxy resin (product name: PKHC, manufactured by Union Carbide, 45,000 weight average molecular weight, Tg: 90°C, bisphenol A skeleton) A2: Phenoxy resin (product name: YD-6020, manufactured by Nippon Steel & Sumitomo Metal Chemical Co., Ltd., weight average molecular weight 5000, Tg: 70°C, bisphenol A/bisphenol F skeleton) A3: Phenoxy resin (product name: FX-316, manufactured by Nippon Steel & Sumitomo Metal Chemical Co., Ltd., weight average molecular weight 50,000, Tg: 70°C, bisphenol F skeleton) A4: Phenoxy resin (product name: FX-293AT40, manufactured by Nippon Steel & Sumitomo Metal Chemical Co., Ltd., Tg: 160°C, high heat resistance skeleton) A5: Polyurethane resin synthesized as described above A6: Polyester resin (product name: UE-3400, manufactured by Unitika Co., Ltd., Tg: -20°C) A7: Polyester resin (product name: UE-3200, manufactured by Unitika Co., Ltd., Tg: 70°C) (radical polymerizable compound) B1: Urethane acrylate synthesized as described above B2: EO-modified diacrylate of isocyanurate (product name: M-215, manufactured by Toagosei Co., Ltd.) B3: 2-Methacryloyloxyethyl phosphate (product name: Light Ester P-2M, manufactured by Kyoeisha Chemical Co., Ltd.) In addition, among the above components, the solid content was used after making a 40 mass % solution prepared by dissolving 40 g of the solid content in 60 g of methyl ethyl ketone.

(radical polymerization initiator) C1: Lauryl peroxide (product name: PEROYL L, manufactured by NOF Corporation, molecular weight 398.6) (filler (filler)) D1: Silicon dioxide fine particles (product name: R104, manufactured by Aerosil Co., Ltd., primary particle size: 12 nm) (Silane coupling agent) E1: 3-Methacryloyloxypropyltrimethoxysilane (product name: KBM-503, manufactured by Shin-Etsu Chemical Co., Ltd.) In addition, the silica fine particle was used based on the dispersion liquid of 10 mass % prepared by dispersing 10 g of silica fine particle in a mixed solvent of 45 g of toluene and 45 g of ethyl acetate.

Next, conductive particles having a nickel layer with a thickness of 0.2 μm, an average particle diameter of 5 μm, and a specific gravity of 2.5 were produced on the surface of the polystyrene particles (cores). The electroconductive particles were dispersed in each adhesive composition at a ratio of 1.5% by volume to obtain a coating liquid. Using a coating device, the coating solution was coated on a polyethylene terephthalate (PET) film with a thickness of 50 μm. The coating film was hot-air dried at 70° C. for 10 minutes to obtain a film-like adhesive with a thickness of 18 μm.

<Fabrication of connection structure> On a flexible printed circuit (FPC) and glass (SiO ₂ ) having about 2200 copper circuit electrodes with a line width of 75 μm, a pitch of 150 μm and a thickness of 18 μm Substrate (product name: PreClean glass slide S7224, manufactured by Matsunami Glass Co., Ltd.), or glass substrate with a thin film of amorphous indium tin oxide (ITO) (manufactured by Geomatec) Each of the film-like adhesives is placed therebetween, and the FPC is connected to the glass substrate or the glass substrate with amorphous ITO. The connection was performed by heating and pressurizing at 160°C and 3 MPa for 5 seconds using a thermocompression bonding apparatus (heating method: constant heat type, manufactured by Toray Engineering Co., Ltd.). . The pressure at the time of pressurization was calculated by setting the crimping area to 0.495 cm ² . Thereby, the connection structure in which the FPC and the glass substrate or the glass substrate with amorphous ITO were connected by the hardened|cured material of the film adhesive over the width of 1.5 mm can be obtained.

<Measurement of Linear Thermal Expansion> Using a laminator, a plurality of the produced film-like adhesives were bonded together so as to have a thickness of 100±20 μm, and heated at 180° C. in an oven for 1 hour. A hardened product sample was produced. A thermomechanical analyzer (manufactured by Shimadzu Corporation) was used for the cured product sample, and the length of the sample was 10 mm, the width was 4 mm, the load was 5 gf (per 0.4 mm ² of the cross-sectional area of the sample), and the heating rate was Under the condition of 5°C/min, the amount of linear thermal expansion l(t) μm at temperature t=0°C to 200°C was measured every 0.1°C. The amount of linear thermal expansion l(t) was measured by setting the amount of linear thermal expansion l(0) at a temperature t=0°C as 0 μm. Based on the measurement results, it is confirmed whether there is a temperature range of dl(t)/dt<0 at a temperature t=30°C to 120°C (if there is, confirm the temperature range and the minimum value of dl(t)/dt). In addition, from the measurement results, the average linear thermal expansion coefficient (ppm/°C) at 30°C to 120°C was calculated. The results are shown in Table 2 and Table 3.

<Evaluation of the presence or absence of peeling> Regarding the connection structure produced in the above-described manner, the appearance of connection immediately after connection and after the high-temperature and high-humidity test placed in a constant temperature and humidity chamber at 85°C and 85%RH for 250 hours was observed with an optical microscope, and the space portion ( The area where peeling occurs at the substrate-resin interface of the electrode terminal of the FPC and the portion between the electrode terminals). The case where the peeling occurrence area of the entire space exceeded 30% was evaluated as "existence" of peeling, and the case of 30% or less was evaluated as "no peeling". The results are shown in Table 2 and Table 3.

[Table 2] Example 1 2 3 4 5 6 7 Adhesive composition thermoplastic resin A1 15 - - - 15 15 15 A2 - 15 - - - - - A3 - - 15 - - - - A4 - - - 15 - - - A5 15 15 15 15 15 - - A6 - - - - - 15 A7 - - - - - - 15 free radical polymerizable compound B1 60 60 60 60 70 60 60 B2 10 10 10 10 - 10 10 B3 3 3 3 3 3 3 3 free radical polymerization initiator C1 3 3 3 3 3 3 3 filler D1 15 15 15 15 15 15 15 Silane coupling agent E1 3 3 3 3 3 3 3 circuit connection member Whether there is a temperature region with dl(t)/dt<0 Have Have Have Have Have Have Have Temperature range (℃) where dl(t)/dt<0 40～60 30～60 40～70 40～60 60～80 30～60 40～50 Minimum value of dl(t)/dt -0.8 -1.5 -2.0 -1.2 -0.7 -1.5 -0.8 Average Linear Thermal Expansion Coefficient (ppm/℃) 144 75 78 80 215 151 122 Has peeling occurred just after connection? Glass none none none none none none none Amorphous ITO none none none none none none none Whether peeling occurs after high temperature and high humidity test Glass none none none none none none none Amorphous ITO none none none none none none none

[table 3] Comparative example 1 2 3 4 5 6 7 8 9 Adhesive composition thermoplastic resin A1 30 - - - - - - 5 15 A2 - 30 - - - - - - - A3 - - 30 - - - - - - A4 - - - 30 - - - - - A5 - - - - 30 - - - - A6 - - - - - 30 - - 15 A7 - - - - - - 30 - - free radical polymerizable compound B1 60 60 60 60 60 60 60 60 60 B2 10 10 10 10 10 10 10 10 10 B3 3 3 3 3 3 3 3 3 3 free radical polymerization initiator C1 3 3 3 3 3 3 3 3 3 filler D1 15 15 15 15 15 15 15 15 15 Silane coupling agent E1 3 3 3 3 3 3 3 3 3 circuit connection member Whether there is a temperature region with dl(t)/dt<0 none none none none none none none none none Average Linear Thermal Expansion Coefficient (ppm/℃) 182 226 165 154 344 85 312 241 77 Has peeling occurred just after connection? Glass none Have none none none none none none none Amorphous ITO Have Have Have Have Have Have Have Have Have Whether peeling occurs after high temperature and high humidity test Glass none Have none none none none none none none Amorphous ITO Have Have Have Have Have Have Have Have Have

From the above, it was confirmed that compared with the circuit connection members of Comparative Examples 1 to 9, the circuit connection members of Examples 1 to 7 can suppress the occurrence of peeling even under high temperature and high humidity conditions.

1: Connect the structure 2: The first circuit component 3: Second circuit component 4: Circuit connection components 5: The first substrate 6: The first circuit electrode 7: Second substrate 8: Second circuit electrode 9: Hardened product of adhesive component 10: Conductive particles L1: At a temperature of t=30°C to 120°C, there is a t-like cured product (circuit connecting member) with dl(t)/dt<0 (dL(t)/dt<0) L2: Cured product (circuit connection member) of adhesive composition that is always dl(t)/dt≧0 (dL(t)/dt≧0) at temperature t=30℃～120℃

FIG. 1 is a schematic cross-sectional view showing an embodiment of a connection structure. FIG. 2 is a graph showing an example of the relationship between the temperature and the amount of linear thermal expansion.

1: Connect the structure

2: The first circuit component

3: Second circuit component

4: Circuit connection components

5: The first substrate

6: The first circuit electrode

7: Second substrate

8: Second circuit electrode

9: Hardened product of adhesive component

10: Conductive particles

Claims (9)

A connection structure including: a first circuit member having a first circuit electrode; a second circuit member having a second circuit electrode; and a circuit connection member provided on the first circuit member and the second circuit member the first circuit electrode and the second circuit electrode are electrically connected to each other, the circuit connection member is a cured product of an adhesive composition containing two or more thermoplastic resins, and the thermoplastic resin includes benzene Oxygen resin, the amount of linear thermal expansion L(t) of the circuit connection member at temperature t satisfies the condition of dL(t)/dt<0 at at least any temperature t from t=30°C to 120°C. The connected structure according to claim 1, wherein the adhesive composition further includes a radically polymerizable compound, and the radically polymerizable compound includes a urethane (meth)acrylate. The connection structure according to claim 1 or 2, wherein the circuit connection member has an average coefficient of linear thermal expansion at 30°C to 120°C of 500 ppm/°C or less. A circuit connection member, wherein the circuit connection member is a cured product of an adhesive composition containing two or more thermoplastic resins, and the thermoplastic resin includes a phenoxy resin, and the circuit connection member has an The amount of linear thermal expansion L(t) is satisfied by The condition of dL(t)/dt<0 at least any temperature t from t=30℃~120℃. The circuit connection member according to claim 4, wherein the adhesive composition further includes a radically polymerizable compound, and the radically polymerizable compound includes a urethane (meth)acrylate. The circuit connection member according to claim 4 or 5, wherein the circuit connection member has an average coefficient of linear thermal expansion at 30°C to 120°C of 500 ppm/°C or less. An adhesive composition comprising two or more thermoplastic resins, wherein the thermoplastic resin comprises a phenoxy resin, and the linear thermal expansion l(t) of the hardened product of the adhesive composition at temperature t satisfies t =Conditions of dl(t)/dt<0 at least any temperature t from 30°C to 120°C. The adhesive composition according to claim 7, wherein the adhesive composition further includes a radically polymerizable compound, and the radically polymerizable compound includes a urethane (meth)acrylate. The adhesive composition according to claim 7 or 8, wherein the cured product has an average coefficient of linear thermal expansion at 30°C to 120°C of 500 ppm/°C or less.

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