TW201816904A - 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; and a first circuit member provided between the first circuit member and the second circuit member. A circuit connection member in which a circuit electrode and a second circuit electrode are electrically connected to each other, and a linear thermal expansion amount L (t) of the circuit connection member at a temperature t satisfies at least dL ( t) / dt <0.

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 devices and display devices, various adhesives have been used for the purpose of bonding various circuit members in the devices to each other. In addition to adhesiveness, the adhesive requires various properties including heat resistance, reliability under high temperature and high humidity conditions, and the like. In addition, for circuit members, for example, organic substrates such as printed wiring boards and polyimide, or metals such as titanium, copper, and aluminum, ITO, IZO, IGZO, SiN, and SiO ₂ have various surface states. Therefore, The materials used in the adhesive need to be molecularly designed according to the circuit components.

Recently, for the purpose of simplifying and lowering the manufacturing steps of semiconductor elements and display elements, the use of amorphous indium tin oxide (ITO) films and organic insulating films in circuit components has continued. increase. In terms of physical viewpoints such as low surface unevenness, or chemical viewpoints such as low surface wettability, these film surfaces are often disadvantageous for adhesion.

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

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

[Problems to be Solved by the Invention] However, according to a study by the present inventors, when using the above-mentioned additives, it exists in a high-temperature and high-humidity environment, and the circuit connection member and the circuit depend on the type of the circuit member. The interaction between the components cannot effectively function, and the problem that the circuit connection component is separated from the circuit component.

Therefore, an object of the present invention is to provide a connection structure capable of suppressing peeling of a circuit connection member from a circuit member even in a high temperature and high humidity environment, and a circuit connection member and an adhesive composition used in the connection structure. [Means for 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 first circuit member and a second circuit member. Circuit connection 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 connection member at a temperature t satisfies at least any one of t = 30 ° C to 120 ° C The condition of dL (t) / dt <0 at temperature t.

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

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

According to another aspect of the present invention, there is provided an adhesive composition, and a linear thermal expansion l (t) of a cured product of the adhesive composition at a temperature t satisfies at least any temperature t from t = 30 ° C to 120 ° C. The condition of dl (t) / dt <0.

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

According to the present invention, it is possible to provide a connection structure capable of suppressing peeling of a circuit connection member from a circuit member even in a high-temperature and high-humidity environment, and a circuit connection member and an adhesive composition used in the connection structure.

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 a 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 a main surface of the second substrate 7.

The first circuit member 2 and the second circuit member 3 may be the same as or different from each other, and may be a wafer component such as a semiconductor wafer, a resistor wafer, or a capacitor wafer, or a substrate such as a printed circuit board. The first substrate 5 and the second substrate 7 can be formed of inorganic materials such as semiconductors, glass, ceramics, organic materials such as polyimide, 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 (which may be singular as appropriate) are usually provided on the substrates 5 and 7 of the circuit members 2 and 3. The first circuit member 2 and the second circuit member 3 are arranged so 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 hardened | cured material 9 of an adhesive agent component, and the electroconductive particle 10 dispersed in the hardened | cured material 9 of an adhesive agent 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 facing each other, whereby the first circuit electrode 6 and the second circuit electrode 8 are electrically connected to each other.

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

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

From the viewpoint of suppressing the peeling of the circuit connection member 4 from the circuit member 2, the circuit member 3, the circuit electrode 6, and the circuit electrode 8, the linear thermal expansion amount L (t) of the circuit connection member 4 is from t = 30 ° C to 120 ° C. At least 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 further preferably dL (T) /dt≦-0.5.

From the viewpoint of suppressing the peeling of the circuit connection member 4 from the circuit member 2, the circuit member 3, the circuit electrode 6, and the circuit electrode 8, the linear thermal expansion amount 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, and still more preferably t = 30 ° C to 80 ° C.

From the viewpoint of suppressing the peeling of the circuit connection 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 of the circuit connection member 4 at 30 ° C to 120 ° C is preferably 500. ppm / ° C or lower, more preferably 250 ppm / ° C or lower, and even more preferably 150 ppm / ° C or lower.

The linear thermal expansion coefficient (ppm / ° C) of the circuit connection member 4 is defined as a linear thermal expansion amount (μm) of the circuit connection member 4 having a length of 1 m for each 1 ° C increase in temperature. The average linear thermal expansion coefficient α _L of the circuit connection member 4 at 30 ° C. to 120 ° C. is the linear thermal expansion amount L (t) of the circuit connection member 4 at t = 30 ° C. to 120 ° C. measured according to the method. The change in [unit: μm / 10 mm] is converted to the linear thermal expansion (μm) of the circuit connection member 4 with a length of 1 m. Based on the converted value, it is the average value for each 1 ° C increase in temperature (that is, according to the following formula) To figure it out. 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 an adhesive composition containing an adhesive component and the conductive particles 10, for example. This adhesive composition is an adhesive composition which is preferably hardened from the viewpoint of suppressing the peeling of the circuit connection member 4 from the circuit member 2, the circuit member 3, the circuit electrode 6, and the circuit electrode 8. The linear thermal expansion amount l (t) of the object at the 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-shaped adhesive having a thickness of 100 ± 20 μm, and curing the film-shaped adhesive by heating at 180 ° C. for 1 hour.

The linear thermal expansion l (t) of the hardened material of the adhesive composition is a thermomechanical analysis device. The length of the specimen is 10 mm, the width is 4 mm, the thickness is 0.1 mm, and the load is 5 gf. Area per 0.4 mm ² ) and temperature increase rate of 5 ° C / min, the linear thermal expansion l (0) = 0 at a temperature of t = 0 ° C to 200 ° C at every 0.1 ° C. The amount of linear thermal expansion (μm) at a temperature t ° C at μm was measured. Here, the amount of linear thermal expansion refers to the amount of linear thermal expansion in the longitudinal direction of the sample.

From the viewpoint of suppressing the peeling of the hardened material (circuit connection member 4) of the adhesive composition from the circuit member 2, the circuit member 3, the circuit electrode 6, and the circuit electrode 8, the linear thermal expansion amount l of the hardened material of the adhesive composition l (T) Satisfying dl (t) /dt≦-0.01, more preferably dl (t) /dt≦-0.1, and more preferably dl (t) at at least any temperature t from t = 30 ° C to 120 ° C. /dt≦-0.5.

From the viewpoint of suppressing the peeling of the hardened material (circuit connection member 4) of the adhesive composition from the circuit member 2, the circuit member 3, the circuit electrode 6, and the circuit electrode 8, the linear thermal expansion amount l of the hardened material of the adhesive composition l (T) At least any temperature t, preferably t = 30 ° C to 100 ° C, more preferably t = 30 ° C to 90 ° C, and still more preferably t = 30 ° C to 80 ° C, satisfies the dl (t ) / Dt conditions.

From the viewpoint of suppressing peeling of the hardened material (circuit connection member 4) of the adhesive composition from the circuit member 2, the circuit member 3, the circuit electrode 6, and the circuit electrode 8, the hardened material of the adhesive composition is at 30 ° C to The average linear thermal expansion coefficient at 120 ° C is preferably 500 ppm / ° C or lower, more preferably 250 ppm / ° C or lower, and even more preferably 150 ppm / ° C or lower.

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

An adhesive composition having such characteristics includes, for example, two or more kinds of resin components having mutually different glass transition temperatures (Tg), components easily causing phase separation between each other, components having a skeleton easily aligned, and having a negative Filler composition of linear thermal expansion coefficient. Examples of the combination of components that are liable to cause phase separation from each other include a combination of components having a large difference in molecular weight between each other, and a combination of components having a large difference in polarity between each other. The combination of components that are likely to undergo phase separation with each other may be specifically: a combination of acrylic resin and epoxy resin, a combination of urethane resin and phenoxy resin, a combination of acrylic rubber and phenoxy resin, acrylic acid The combination of rubber and epoxy. Examples of the component having a skeleton that can be easily aligned include a component including an alkyl chain, a component including a phenyl group, and the like. The inventors of the present invention have considered that when the adhesive composition contains the above-mentioned components, the cured product (circuit connection member 4) of the obtained adhesive composition has microscopic voids reduced due to temperature rise, and molecular chains. Shrinkage (volume phenomenon) due to temperature re-alignment and re-arrangement of filler components.

The adhesive agent composition in one embodiment preferably contains: (a) a thermoplastic resin (hereinafter also referred to as "(a) component"), (b) a radical polymerizable compound (hereinafter also referred to as "(b) component" "), And (c) a radical polymerization initiator (hereinafter also referred to as" (c) component ").

The component (a) is not particularly limited, and examples thereof include polyimide resins, polyimide resins, phenoxy resins, poly (meth) acrylic resins, polyester resins, and polyurethanes. Resin, polyester urethane resin, and polyvinyl butyral resin, one or two or more resins.

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

When the adhesive composition contains two or more thermoplastic resins having different Tgs, from the viewpoint of easily obtaining a cured product (circuit connection member 4) of the adhesive composition having a desired amount of linear thermal expansion, the adhesive composition has a further advantage. 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, and more preferably 90/10 to 20/80 It is further preferably 90/10 to 30/70. In the case where the adhesive composition contains three or more thermoplastic resins having different Tgs, the adhesive composition is preferably such that the ratio of the content of the thermoplastic resin having the highest Tg to the thermoplastic resin having the lowest Tg becomes Contains by way of.

The weight average molecular weight of the thermoplastic resin is preferably 5,000 or more, more preferably 10,000 or more, and more preferably 400,000 or less, more preferably 200,000 or less, and even 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 increase. 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 a weight average molecular weight (standard polystyrene conversion value) measured by gel permeation chromatography (GPC).

From the viewpoint of stress relaxation and further improvement in adhesiveness, the adhesive composition may contain a rubber component as a thermoplastic resin. Examples of the rubber component include silicone rubber, acrylic rubber, polyisoprene rubber, polybutadiene rubber, carboxy-terminated polybutadiene rubber, hydroxyl-terminated polybutadiene rubber, and 1,2-polybutadiene Rubber, carboxy-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 particulate. The average particle diameter of the rubber particles is preferably not more than twice the average particle diameter of the conductive particles 10, and is, for example, 0.01 μm to 100 μm. The storage elastic coefficient of the rubber particles at room temperature (25 ° C) is preferably 1/2 or less of the storage elastic coefficient of the conductive particles 10 and the adhesive composition at room temperature, and is, for example, 0.1 MPa to 100 MPa. From the viewpoint of excellent solvent resistance and easy dispersion in the adhesive composition, the rubber particles are preferably three-dimensionally crosslinked rubber particles.

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, based on 100 parts by mass of the total amount of the components (a) and (b). It is 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 (a) is 20 parts by mass or more, the adhesion force is further improved. In addition, the film formability of the adhesive composition tends to be improved. When it is 80 parts by mass or less, the fluidity of the adhesive agent 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 (b) component is preferably a polyfunctional (meth) acrylate compound having two or more (meth) acryloxy groups. Examples of such a (meth) acrylate compound include epoxy (meth) acrylate, urethane (meth) acrylate, polyether (meth) acrylate, and polyester (meth) Polyalkylene glycol di (meth) acrylates such as acrylate, trimethylolpropane tri (meth) acrylate, and polyethylene glycol di (meth) acrylate; dicyclopentenyl (methyl ) Acrylate, dicyclopentenyloxyethyl (meth) acrylate, neopentyl glycol di (meth) acrylate, dipentaerythritol hexa (meth) acrylate, isocyanurate modified bifunctional ( (Meth) acrylate, isocyanurate modified trifunctional (meth) acrylate, and the like. Examples of the epoxy (meth) acrylate include epoxy (meth) acrylate to which (meth) acrylic acid is added to two glycidyl groups of bisphenol diglycidyl ether, and (meth) acrylate ) Acryloxy group is introduced into a compound of a compound obtained by adding ethylene glycol and / or propylene glycol to two glycidyl groups of bisphenol diglycidyl ether. Among these (meth) acrylate compounds, a urethane (meth) acrylate is preferably used from the viewpoint of obtaining a better adhesiveness by having a urethane bond. These compounds may be used alone or in combination of two or more.

From the viewpoint of adjustment of fluidity, the adhesive composition may contain a monofunctional (meth) acrylate compound as the component (b). 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) acryloxyethyl phosphate, N, N- Dimethylaminoethyl (meth) acrylate, N, N-dimethylaminopropyl (meth) acrylate, (meth) acrylic acid and epoxy having multiple glycidyl groups Glycidyl group Glycidyl (meth) acrylate, and (meth) Bing Xixi morpholine. These compounds may be used alone or in combination of two or more.

From the viewpoint of improving the crosslinking rate, 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 a component (b). Examples of such compounds include N-vinylimidazole, N-vinylpyridine, N-vinylpyrrolidone, N-vinylformamide, N-vinylcaprolactam, 4,4 ' -Vinylidene bis (N, N-dimethylaniline), N-vinylacetamide, N, N-dimethylpropylamine, N-isopropylacrylamide and N, N-diethylamine Acrylamide.

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

[Chemical 1] In formula (1), R ¹ represents a hydrogen atom or a methyl group, R ² represents a (meth) acrylfluorenyl 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 as or different from each other.

[Chemical 2] In the formula (2), R ³ represents a (meth) acrylic fluorenyloxy 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 as or different from each other.

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

Examples of the radically polymerizable compound having a phosphate ester structure include acidic phosphonoethyl (meth) acrylate, acidic phosphonopropyl (meth) acrylate, and acidic phosphooxypolyoxyethylene Alcohol mono (meth) acrylate, acid phosphonic polyoxypropylene glycol mono (meth) acrylate, 2,2'-bis (meth) acrylic acid oxydiethyl phosphate, 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 even more preferably 35 parts by mass based on 100 parts by mass of the total amount of the components (a) and (b). It is preferably at least 80 parts by mass, more preferably at most 70 parts by mass, and even more preferably at most 65 parts by mass. When the content of the component (b) is 20 parts by mass or more, the heat resistance of the cured product of the adhesive composition (circuit connection member 4) tends to be improved. When the content of the component (80) is 80 parts by mass or less, high temperature and high humidity can be further suppressed. The tendency of the circuit connection member 4 to peel under the environment.

When the adhesive composition contains a radical polymerizable compound having a phosphate ester structure as the component (b), the radical having a phosphate ester structure is 100 parts by mass of 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 more preferably 15 parts by mass or less, and more preferably 10 parts by mass or less. When the content of the radical polymerizable compound having a phosphate ester structure is 0.1 parts by mass or more, the adhesive strength of the adhesive composition tends to be further increased. When it is 15 parts by mass or less, it is difficult to produce the adhesive composition. The hardened material (circuit connection member 4) tends to have lower physical properties and improved reliability.

The component (c) can be arbitrarily selected from compounds such as peroxides and azo compounds. From the viewpoint of excellent stability, reactivity, and compatibility, it is preferable to use a peroxide having a half-life temperature of 90 ° C. to 175 ° C. and a molecular weight of 180 to 1,000 as a component (c). The "1-minute half-life temperature" refers to a temperature at which the half-life of peroxide is 1 minute. "Half-life" refers to the time at which the concentration of a compound decreases to half the initial value at a predetermined temperature.

The radical polymerization initiator may be, for example, one or more compounds selected from the group consisting of 1,1,3,3-tetramethylbutylperoxy neodecanoate, bis (4-thirdbutylcyclohexyl) ) Peroxydicarbonate, bis (2-ethylhexyl) peroxydicarbonate, cumyl peroxyneodecanoate, 1,1,3,3-tetramethylbutyl peroxydecanoate, peroxy Dilauryl oxide, 1-cyclohexyl-1-methylethyl neodecanoate, third hexylperoxynedecanoate, third butylperoxynedecanoate, third butylperoxy Pivalate, 1,1,3,3-tetramethylbutyl peroxy-2-ethylhexanoate, 2,5-dimethyl-2,5-bis (2-ethylhexyl) Peroxy) hexane, third hexylperoxy-2-ethylhexanoate, third butylperoxy-2-ethylhexanoate, third butylperoxypeptanoate, third pentyl Peroxy-2-ethylhexanoate, di-tert-butylperoxyhexahydroterephthalate, tert-pentylperoxy-3,5,5-trimethylhexanoate, 3- Hydroxy-1,1-dimethylbutyl peroxyneodecanate, 1,1,3,3-tetramethylbutyl peroxy-2-ethylhexanoate, third pentyl neodecanoate Acid ester Tertiary pentyl peroxy-2-ethylhexanoate, 3-methylbenzylidene peroxide, 4-methylbenzylidene peroxide, bis (3-methylbenzylidene) ) Peroxide, benzophenylidene peroxide, bis (4-methylbenzylidene) peroxide, 2,2'-azobis-2,4-dimethylvaleronitrile, 1, 1'-azobis (1-ethoxyl-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) ), The third hexyl peroxide isopropyl monocarbonate, the third butyl peroxymaleate, the tert-butyl peroxy-3,5,5-trimethylhexanoate, the third butyl peroxy Oxidized laurate, 2,5-dimethyl-2,5-bis (3-methylbenzylideneperoxy) hexane, tert-butylperoxy-2-ethylhexyl monocarbonate, Trihexyl peroxybenzoate, 2,5-dimethyl-2,5-bis (benzylidene peroxy) hexane, third butyl peroxybenzoate, dibutyl triperoxide Methyl adipate, third pentyl peroxyoctanoate, third pentyl isononanoate, and third pentyl Benzoyl peroxide.

From the viewpoint of suppressing the corrosion of the circuit electrode 6 and the circuit electrode 8, the content of chloride ion or organic acid in the radical polymerization initiator is preferably 5000 ppm or less, and it is more preferable to use an organic acid 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% by mass or more after standing in the air 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 with respect to 100 parts by mass of the total amount of the components (a) and (b). It is 15 parts by mass or less, and more preferably 10 parts by mass or less.

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

(D) The epoxy resin is a resin having at least one epoxy group in the molecule. Examples of the epoxy resin include bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, phenol novolac epoxy resin, cresol novolac epoxy resin, and Novolac novolac epoxy resin, bisphenol F novolac epoxy resin, alicyclic epoxy resin, glycidyl ester epoxy resin, glycidylamine epoxy resin, hydantoin type 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 based on 100 parts by mass of the total amount of the components (a) and (d). It is preferably 90 parts by mass or less, more preferably 80 parts by mass or less, and even more preferably 70 parts by mass or less. When the content of the component (d) is 10 parts by mass or more, there is a tendency that better adhesion is obtained, and when it is 90 parts by mass or less, the viscosity is small and the workability tends to be good.

(E) The hardener (also referred to as "epoxy polymerization initiator" or "latent hardener") may be any hardener that can harden (d) the epoxy resin. Examples of the curing agent include anionic polymerizable catalyst-type curing agents, cationic polymerizable catalyst-type curing agents, and addition polymerization-type curing agents. These may be used alone or in combination of two or more. From the viewpoint of being excellent in rapid hardening property and without considering chemical equivalent, the (e) hardening agent is preferably an anionic polymerizable or cationic polymerizable catalyst hardener.

Examples of the anionic polymerizable or cationic polymerizable catalyst-type hardener include imidazole-based hardeners, hydrazine-based hardeners, boron trifluoride-amine complexes, onium salts such as sulfonium salts and diazonium salts, Aminimide, diaminomaleonitrile, melamine and its derivatives, salts of polyamines, dicyandiamine, and the like can also be used.

When a compound having a tertiary amine group, an imidazole compound, or the like is used as the anionic polymerizable catalyst-type hardener, the epoxy resin is heated for several tens of seconds to several hours at a temperature of about 160 ° C to 200 ° C. And hardened. Therefore, the pot life of the adhesive composition can be prolonged. As the cationic polymerizable catalyst-type curing agent, for example, a photosensitive onium salt (aromatic diazonium salt, aromatic sulfonium salt, or the like) that hardens the epoxy resin by irradiation with energy rays can be preferably used. Examples of the cationic polymerizable catalyst-type curing agent that is activated by heating and hardens the epoxy resin include aliphatic sulfonium salts and the like. In terms of rapid curing, these anionic polymerizable or cationic polymerizable catalyst-type hardeners can be preferably used.

Examples of the addition polymerization-type curing agent include polyamines, polythiols, polyphenols, and acid anhydrides.

In terms of obtaining a longer usable time, it is preferable to cover these with a polymer compound such as polyurethane, polyester, a metal film such as nickel, copper, or an inorganic substance such as calcium silicate. Hardeners (potential hardeners) and microencapsulated microencapsulated hardeners.

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, based on 100 parts by mass of the total amount of the components (a) and (d), and more preferably 80 parts by mass or less, more preferably 70 parts by mass or less.

Examples of the conductive particles 10 include metal particles such as Au, Ag, Ni, Cu, and solder; and conductive particles such as conductive carbon particles. The conductive particle 10 may be a coated conductive particle including a core including particles such as non-conductive glass, ceramics, and plastic; and a layer made of the metal, metal particles, and conductive carbon particles covering the core. Wait. In the case where the conductive particles 10 are coated with conductive particles or metal particles (hot-melt metal particles) that are melted by heat, the conductive particles 10 are deformed by heat and pressure during circuit connection, so even circuit electrodes 6. The height of the circuit electrode 8 varies, and the contact area of the conductive particles 10 with the circuit electrode 6 and the circuit electrode 8 is also increased to obtain good reliability. In particular, when the amount of the conductive particles 10 is increased, short circuits between the conductive particles 10 are prevented, and adjacent first circuit electrodes 6 and between the first circuit electrodes 6 or between the second circuit electrodes 8 and the second circuit are raised. From the viewpoint of the insulation between the electrodes 8, the conductive particles 10 may be the insulation coating conductivity provided with the conductive particles and the surface covering the conductive particles, and an insulation coating layer made of an insulating material such as a polymer resin. particle. These conductive particles, coated conductive particles, and insulated coated conductive particles may be used alone or in combination of two or more.

From the viewpoint of excellent dispersibility and conductivity, the average particle diameter of the conductive particles 10 is preferably 1 μm to 50 μm. Based on the total amount of the adhesive composition, the content of the conductive particles is preferably 0.1% by volume or more, more preferably 30% by volume or less, and more preferably 10% by volume or less. When the content is 0.1% by volume or more, the conductivity tends to be further improved. When the content is 30% by volume or less, the adjacent first circuit electrodes 6 and between the first circuit electrodes 6 or between the second circuit electrodes 8 and the first The tendency of short circuits between the two circuit electrodes 8. The content of the conductive particles 10 is determined based on the volume of each component of the adhesive composition (before curing) at 23 ° C. The volume of each component can be, for example, a value converted to volume by weight using specific gravity. 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 graduated cylinder or the like, and the component may be added and the increased volume may be used as the volume. Find it out.

In addition to (a) component, (b) component, (c) component and conductive particle 10 or (a) component, (d) component, (e) component and conductive particle 10, the adhesive composition may further contain Other resins such as phenol resin and melamine resin, fillers (fillers), softeners, hardening accelerators, anti-aging agents, colorants, flame retardants, thixotropic agents, coupling agents, and other adhesion promoters, thickeners, and leveling agents Agents, weather resistance improvers, 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, or a compound containing them, an organic compound, or the like particle of. The average particle diameter of the particles is preferably ½ or less of the average particle diameter of the conductive particles 10, and is, for example, 0.005 μm to 25 μm. When the adhesive composition contains particles having no conductivity (for example, the rubber particles), the average particle diameter of the particles used as a filler may be equal to or smaller than the average particle diameter of the particles having no conductivity.

From the viewpoint of further improving electrical characteristics such as connection reliability between the circuit electrode 6 and the circuit electrode 8 by using a hardened product (circuit connection member 4) of the adhesive composition having a desired linear thermal expansion amount, the filler is A filler having a negative average linear thermal expansion coefficient at 30 ° C to 120 ° C is preferred. Examples of the filler having a negative average linear thermal expansion coefficient at 30 ° C to 120 ° C include particles made of a zirconium-based compound.

The content of the filler is preferably 5 parts by mass or more with respect to 100 parts by mass of the adhesive composition, and more preferably 60 parts by mass or less. When the content is 60 parts by mass or less, there is a tendency that the effect of improving connection reliability is more fully 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 adhesion 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) acryloxypropylmethyldimethoxysilane, 3- (meth) acryloxypropyltrimethoxysilane, 3- (meth) acryloxy Propylmethyldiethoxysilane, 3- (meth) acryloxypropyltriethoxysilane, N-2- (aminoethyl) -3-aminopropylmethyldimethoxy Silane, N-phenyl-3-aminopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-isocyanatepropyltriethoxy Silane and these condensates.

The content of the coupling agent is preferably 0.1 parts by mass or more, more preferably 0.25 parts by mass, with respect to 100 parts by mass of the adhesive component (for example, (a) component to (e) component) 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 of the circuit member and the circuit connection member tends to be further suppressed. When the content of the coupling agent is 10 parts by mass or less, the usable time of the adhesive composition is increased. Increasing tendency.

When the adhesive composition is in a liquid state at, for example, 15 ° C to 25 ° C, it can be used as a paste-like 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 it can be dissolved in a solvent and used as a paste adhesive composition. The solvent is not particularly limited as long as it is a solvent that is not reactive with the components contained in the adhesive composition and exhibits sufficient solubility in the components contained in the adhesive composition. A boiling point at atmospheric pressure is preferably used. A solvent at 50 ° C to 150 ° C. When the boiling point is 50 ° C or higher, the solvent can be prevented from volatilizing at room temperature (25 ° C), and the 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 reliability after the bonding can be ensured.

The adhesive composition can also be used as a film-like adhesive. The adhesive composition is, for example, a solution containing a solvent or the like added to the adhesive composition, if necessary, and applied to a release substrate such as a fluororesin film, a polyethylene terephthalate film, a release paper, or the like. A substrate such as a non-woven fabric is impregnated with a solution and placed on a peelable substrate, and thereafter, the solvent and the like are removed to form a film. From the viewpoints of workability and the like, a film-like adhesive is preferably used.

The adhesive composition can be used as a circuit connection material typified by an anisotropic conductive adhesive, silver paste, silver film, etc., an elastomer for chip scale packaging (CSP), an underfill for CSP, and communication Material of semiconductor elements such as line of communication (LOC) tapes.

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 face each other so that the film-shaped adhesive is interposed between the first A circuit member 2 and a second circuit member 3 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 pressing is not particularly limited as long as it does not cause damage to the adherend (circuit member 2, circuit member 3), and is preferably 0.1 MPa to 10 MPa. The heating and pressing 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, light can be irradiated simultaneously with heating and pressurization from the viewpoint of lower temperature and shorter time connection. The light irradiation preferably uses irradiation light in a wavelength range of 150 nm to 750 nm. Light irradiation can be performed 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 at an irradiation amount of 0.1 J / cm ² to 10 J / cm ² .

As described above, the cured product of the adhesive composition (circuit connection member 4), for example, as shown by L1 in FIG. 2, exists at a temperature t = 30 ° C. to 120 ° C. and dl (t) / dt <0 (dL) (T) / dt <0) is a t-like hardened material (circuit connection member), which can reduce the thermal expansion of the circuit connection member 4 itself as the temperature rises, and may cause the circuit connection member 4 to the substrate 5 and the substrate 7 And the interfacial stress (the stress to peel off the circuit connection member 4 from the substrate 5, the substrate 7, 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, as shown by L2 in FIG. 2, the hardened product (circuit connection member) of the conventional adhesive composition is always dl (t) / dt ≧ 0 ( dL (t) / dt ≧ 0) is a hardened material of the adhesive composition (circuit connection member), so as the temperature rises, the circuit connection member 4 itself is prone to thermal expansion, and the circuit connection member 4 and the substrate 5 and the substrate 7 A large peeling interface stress occurs at the interface between the circuit electrode 6 and the circuit electrode 8.

Therefore, compared with the hardened | cured material (circuit connection member) of the conventional adhesive agent composition, the hardened | cured material (circuit connection member 4) of the adhesive agent composition of this embodiment is a case where it is exposed to high temperature and high humidity. It is also possible to prevent the circuit connecting member 4 from being peeled from the substrate 5, the substrate 7, the circuit electrode 6, and the circuit electrode 8. This effect can also be exhibited in the case where a circuit electrode made of amorphous ITO or the like, which is not conducive to adhesion, is used as the circuit electrode 6 and the circuit electrode 8. [Example]

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

<Synthesis of Polyurethane Resin> In a separable flask equipped with a reflux cooler, a thermometer, and a stirrer, 1,000 parts by mass of polypropylene glycol (quantity average molecular weight: 2000) as a diol having an ether bond was added as 4000 parts by mass of methyl ethyl ketone in the solvent was stirred at 40 ° C for 30 minutes. After this solution was heated to 70 ° C, 0.127 parts by mass of dibutyltin laurate was added as a catalyst. Next, to this solution, 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 over 1 hour. Thereafter, stirring was continued at 70 ° C. until an absorption peak derived from an NCO group was not observed by an infrared spectrophotometer, thereby obtaining a methyl ethyl ketone solution of a polyurethane resin. Then, the amount of methyl ethyl ketone was adjusted so that the solid content concentration (concentration of the polyurethane resin) of the solution was 30% by mass.

The glass transition temperature (Tg) of the obtained polyurethane resin was -20 ° C. The glass transition temperature (Tg) was measured using a thermomechanical analysis device.

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]

<Synthesis of Urethane Acrylate> A 2 L four-necked flask equipped with a thermometer, a stirrer, an inert gas inlet, and a reflux cooler was added with a polycarbonate diol (manufactured by Aldrich) (Number average molecular weight: 2000) 4000 parts by mass, 238 parts by mass of 2-hydroxyethyl acrylate, 0.49 parts by mass of hydroquinone monomethyl ether, and 4.9 parts by mass of tin-based catalyst to prepare a reaction solution. To the reaction solution heated to 70 ° C., 666 parts by mass of isophorone diisocyanate (IPDI) was added dropwise uniformly over 3 hours to cause a reaction. After completion of the dropwise addition, the reaction was continued for 15 hours, and the reaction was completed at a time point when it was confirmed that the content of NCO groups was 0.2% by mass or less using a potentiometric automatic titration device (product name AT-510, manufactured by Kyoto Electronics Industry Co., Ltd.) to obtain amine Urethane acrylate. The weight average molecular weight of the urethane acrylate was 8,500. The weight average molecular weight of the urethane acrylate is measured in the same manner as the weight average molecular weight of the polyurethane resin.

<Production of film-shaped 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, Union Carbide), weight average molecular weight 45000, Tg: 90 ° C, bisphenol A skeleton) A2: phenoxy resin (product name : YD-6020, manufactured by Nippon Steel & Sumitomo Chemical Co., Ltd., weight average molecular weight 5000, Tg: 70 ° C, bisphenol A / bisphenol F skeleton) A3: phenoxy resin (product name: FX-316, Shinichi Manufactured by Tetsusumi Chemical Co., Ltd., weight average molecular weight 50000, Tg: 70 ° C, bisphenol F skeleton) A4: phenoxy resin (product name: FX-293AT40, manufactured by Nippon Steel & Sumitomo Chemical Co., Ltd., Tg: 160 ℃, 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: amine group synthesized as described above Formate acrylate B2: isocyanurate EO modification Diacrylate (product name: M-215, manufactured by Toa Synthetic Co., Ltd.) B3: 2-methacryloxyethyl phosphate (product name: Light Ester) P-2M, Kyoeisha Chemical Co., Ltd. Co., Ltd.) Furthermore, among the above components, the solid component is used as a 40% by mass solution prepared by dissolving 40 g of the solid content in 60 g of methyl ethyl ketone.

(Free radical polymerization initiator) C1: Laurel peroxide (product name: PEROYL L, manufactured by Nippon Oil Co., Ltd., molecular weight 398.6) (filler (filler)) D1: fine particles of silicon dioxide ( Product name: R104, manufactured by Japan Aerosil Co., Ltd., primary particle size: 12 nm) (silane coupling agent) E1: 3-methacryloxypropyltrimethoxysilane (product name: KBM-503, manufactured by Shin-Etsu Chemical Industry Co., Ltd.) Furthermore, the silica particles were prepared by dispersing 10 g of silica particles in a mixed solvent of 45 g of toluene and 45 g of ethyl acetate. It is used based on the mass% dispersion.

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

<Fabrication of connection structure> Flexible printed circuit (FPC) and glass (SiO ₂ ) with approximately 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 Songlang Glass Industry Co., Ltd.), or glass substrate with amorphous indium tin oxide (ITO) film (manufactured by Geomatec) Each of the film-like adhesives is arranged between the FPC and a glass substrate or a glass substrate with amorphous ITO. The connection was performed by using a thermocompression bonding device (heating method: constant heat type, manufactured by Toray Engineering Co., Ltd.), and heating and pressing at 160 ° C and 3 MPa for 5 seconds. . The pressure during pressing was calculated by setting the crimping area to 0.495 cm ² . Thereby, it is possible to obtain a connection structure in which the FPC and the glass substrate or the glass substrate with amorphous ITO are connected to each other across a width of 1.5 mm by a cured product of a film-like adhesive.

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

<Evaluation of the presence or absence of peeling> Regarding the connection structure produced as described above, an optical microscope was used to observe the temperature immediately after the connection and after a high-temperature and high-humidity test in a constant temperature and humidity tank at 85 ° C and 85% RH for 250 hours. The appearance of the connection was measured, and the peeling area of the substrate-resin interface in the space portion (the portion between the electrode terminal and the electrode terminal of the FPC) was measured. The case where the peeling area of the entire space exceeds 30% is evaluated as "present" peeling, and the case where 30% or less is evaluated as "no" peeling. The results are shown in Tables 2 and 3.

[Table 2]

[table 3]

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‧‧‧ connection structure

2‧‧‧First Circuit Component

3‧‧‧second circuit component

4‧‧‧Circuit connection components

5‧‧‧ the first substrate

6‧‧‧First circuit electrode

7‧‧‧ second substrate

8‧‧‧Second circuit electrode

9‧‧‧ Adhesive hardener

10‧‧‧ conductive particles

L1‧‧‧ has a t-like hardened material (circuit connection member) with dl (t) / dt <0 (dL (t) / dt <0) at temperature t = 30 ℃ ～ 120 ℃

L2‧‧‧ A hardened product (circuit connection member) of an adhesive composition that has been dl (t) / dt ≧ 0 (dL (t) / dt ≧ 0) at a temperature of t = 30 ° C to 120 ° C.

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

Claims (6)

A connection structure includes: 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, and a linear thermal expansion amount L (t) of the circuit connection member at a temperature t satisfies at least t = 30 ° C to 120 ° C The condition of dL (t) / dt <0 at any temperature t. The connection structure according to item 1 of the scope of patent application, wherein the average linear thermal expansion coefficient of the circuit connection member at 30 ° C to 120 ° C is 500 ppm / ° C or less. A circuit connection member, wherein a linear thermal expansion amount L (t) of the circuit connection member at a temperature t satisfies a condition of dL (t) / dt <0 at at least any temperature t from t = 30 ° C to 120 ° C. . The circuit connection member according to item 3 of the scope of patent application, wherein the average linear thermal expansion coefficient of the circuit connection member at 30 ° C to 120 ° C is 500 ppm / ° C or less. An adhesive composition, wherein a linear thermal expansion amount l (t) of the hardened product of the adhesive composition at a temperature t satisfies at least any temperature t at a temperature dl (t) / The condition of dt <0. The adhesive composition according to item 5 of the scope of the patent application, wherein the average linear thermal expansion coefficient of the cured product at 30 ° C to 120 ° C is 500 ppm / ° C or less.