TWI734841B - 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 a circuit electrode and a second circuit electrode are electrically connected to each other, and the linear thermal expansion amount L(t) of the circuit connection member at temperature t satisfies dL( t)/dt<0.

Description

Connection structure, circuit connection member and adhesive composition

The 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. For adhesives, in addition to adhesiveness, heat resistance, reliability in high-temperature and high-humidity conditions, and other properties related to various aspects are also required. In addition, circuit members use organic substrates such as printed wiring boards, polyimide, or metals such as titanium, copper, aluminum, ITO, IZO, IGZO, SiN, and SiO _{2 that} have various surface conditions. The materials used in the adhesive need to be molecularly designed according to the circuit components.

Recently, for the purpose of simplifying the manufacturing steps of semiconductor elements and display elements, and lowering the temperature, the use of amorphous indium tin oxide (ITO) films and organic insulating films in circuit components has also continued. Increase. From a physical point of view, such as less surface irregularities, or a chemical point of view, such as low wettability of the surface, these film surfaces are often unfavorable for bonding.

On the other hand, in order to strengthen the adhesion between the circuit connection member and the circuit member obtained by curing the adhesive, there are sometimes covalent bonds, hydrogen bonds, and van der Waals between the circuit connection member and the surface of the circuit member. Additives such as interaction-like coupling agents such as hydrophobic interactions caused by van der Waals force 着剂中. As the coupling agent, a silane coupling agent, a coupling agent having a phosphoric acid group, a carboxyl group, and the like can be used. For example, in the resin used to form the circuit connection member, there are organic functional groups such as epoxy group, acryl group, and vinyl group, and it has an alkoxysilane structure, phosphoric acid, etc., which generates an 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 (refer to Patent Document 1 to Patent Document 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

However, according to the research of the inventors, in the case of using the above additives, it exists in a high temperature and high humidity environment, and the interaction between the circuit connection member and the circuit member cannot be effective depending on the type of the circuit member. The ground function, the circuit connection member is peeled from the circuit member.

Therefore, an object of the present invention is to provide a connection structure that can suppress peeling of the circuit connection member from the circuit member even in a high-temperature and high-humidity environment, and a circuit connection member and adhesive composition used in the connection structure.

The present invention provides a connection structure in one aspect, which has: The first circuit member of the first circuit electrode; the second circuit member having the second circuit electrode; The circuit connection member, and the linear thermal expansion amount L(t) of the circuit connection member 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.

In another aspect, the present invention provides a circuit connection member, the linear thermal expansion amount L(t) of the circuit connection member at a temperature t satisfies dL(t)/ at least any temperature t from t=30°C to 120°C 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 less.

In another aspect, the present invention provides an adhesive composition in which the linear thermal expansion l(t) of the 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 product at 30°C to 120°C is preferably 500 ppm/°C or less.

According to the present invention, it is possible to provide a connection structure that can prevent the circuit connection member from peeling off the circuit member even in a high-temperature and high-humidity environment, and a circuit connection member and adhesive composition used in the connection structure.

1: Connection structure

2: The first circuit component

3: The second circuit component

4: Circuit connection member

5: The first substrate

6: The first circuit electrode

7: Second substrate

8: second circuit electrode

9: Hardened material of the adhesive component

10: Conductive particles

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

L2: Hardened product (circuit connection member) of an adhesive composition like dl(t)/dt≧0 (dL(t)/dt≧0) at a temperature of 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 temperature and linear thermal expansion.

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" refers to 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 wafers, resistor wafers, capacitor wafers, etc., substrates such as printed circuit boards, and the like. The first substrate 5 and the second substrate 7 may be formed of inorganic materials such as semiconductors, glass, and ceramics, organic materials 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 (which may be singular as the case may be) are usually provided on the circuit components 2, the substrate 5 and the substrate 7 of the circuit component 3. The first circuit member 2 and the second circuit member 3 have at least a pair of first circuit electrodes 6 and a second circuit electrode 6 The circuit electrodes 8 are arranged such that they face each other.

The circuit connection member 4 contains a cured product 9 of the adhesive component and 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 facing 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: from the viewpoint of suppressing peeling of the circuit connection member 4 from the circuit member 2, the circuit member 3, the circuit electrode 6, the circuit electrode 8, the temperature of the circuit connection member 4 at the temperature t°C The amount of linear thermal expansion L(t)μm satisfies the condition of dL(t)/dt<0 at at least any temperature t from t=30°C to 120°C.

The amount of linear thermal expansion L(t) of the circuit connection member 4 is based on a thermomechanical analysis device. The length of the sample is 10mm, the width is 4mm, the thickness is 0.1mm, the load is 5gf (cross-sectional area per 0.4mm ² ), and the temperature rise rate Under the condition of 5°C/min, the linear thermal expansion at temperature t°C when the temperature t=0°C is set every 0.1°C at a temperature of t=0°C~200°C, L(0)=0μm The amount (μm) is 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 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 at t=30℃~120℃ At least any temperature t satisfies the condition of dL(t)/dt<0, preferably dL(t)/dt≦-0.01, more preferably dL(t)/dt≦-0.1, and more preferably dL (t)/dt≦-0.5.

In order to suppress the circuit connection member 4 from the circuit member 2, the circuit member 3 and the electrical From the viewpoint of the peeling of 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 100°C, more preferably t=30°C to 90°C, and further Preferably, t=at least any temperature t from 30°C to 80°C satisfies the dL(t)/dt condition.

From the viewpoint of suppressing 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 less, more preferably 250 ppm/°C or less, and still more preferably 150 ppm/°C or less.

The coefficient of linear thermal expansion (ppm/°C) of the circuit connection member 4 is defined as the amount of linear thermal expansion (μm) of the circuit connection member 4 with a length of 1 m for every 1°C increase in temperature. The average linear thermal expansion coefficient α _L of the circuit connecting member 4 at 30°C to 120°C is the linear thermal expansion amount L(t) of the circuit connecting member 4 measured according to the method at t=30°C to 120°C [Unit: μm/10mm] The amount of change is converted to the linear thermal expansion (μm) of the length of 1m of the circuit connection member 4, and the converted value is calculated as the average value for every 1°C increase in temperature (that is, according to the following formula) .

α _L ={L(t=120℃)-L(t=30℃)}×100/(120-30)

The cured product 9 and the conductive particles 10 constituting the adhesive component of the circuit connection member 4 are selected so that the circuit connection member 4 has the above-mentioned characteristics. The circuit connection member 4 is obtained, for example, by curing an adhesive composition containing an adhesive component and conductive particles 10. The adhesive composition is the following adhesive composition: it suppresses electricity From the viewpoint of 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, it is preferably the linear thermal expansion l(t) of the cured product of the adhesive composition at the temperature t It satisfies the condition of dl(t)/dt<0 at least at 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 linear thermal expansion l(t) of the cured product of the adhesive composition is measured by using a thermomechanical analysis device. The length of the sample is 10mm, the width is 4mm, the thickness is 0.1mm, and the load is 5gf (the cross-sectional area of the sample is 0.4 mm ² ), the temperature rise rate is 5℃/min, at a temperature t=0℃~200℃, every 0.1℃ is set as the temperature when the linear thermal expansion l(0)=0μm at the temperature t=0℃ The amount of linear thermal expansion (μm) at t°C 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, the circuit electrode 6, and the circuit electrode 8, the linear thermal expansion of the cured product of the adhesive composition l (t) At least any temperature t from t=30°C to 120°C, satisfy dl(t)/dt≦-0.01, more preferably dl(t)/dt≦-0.1, and more preferably dl(t) /dt≦-0.5.

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 linear thermal expansion of the cured product of the adhesive composition l (t) At least any temperature t that is preferably t=30°C~100°C, more preferably t=30°C~90°C, and more preferably t=30°C~80°C, satisfies the dl(t )/dt conditions.

From the viewpoint of suppressing the peeling of the cured product (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 cured product of the adhesive composition should be at a temperature of 30°C~ 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 coefficient of linear thermal expansion (ppm/°C) of the cured product of the adhesive composition is defined as the amount of linear thermal expansion (μm) of the cured product of the adhesive composition of 1 m in length for every 1°C increase in temperature. The average linear thermal expansion coefficient α ₁ of the cured product of the adhesive composition at 30°C to 120°C 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/10mm] is converted to the linear thermal expansion (μm) of the cured product of the adhesive composition with a length of 1m, and the converted value is used as the average value for every 1°C increase in temperature (That is, it is calculated according to the following formula).

α ₁ ={1(t=120℃)-1(t=30℃)}×100/(120-30)

Adhesive compositions with such characteristics include, for example, two or more resin components having mutually different glass transition temperatures (Tg), components that are easily phase-separated from each other, components that have a skeleton that is easy to align, and components that have a negative The linear thermal expansion coefficient of the filler composition and so on. 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 between each other, a combination of components with a large difference in polarity between each other, and the like can be cited. The combination of components that are likely to separate from each other, specifically It can be: a combination of acrylic resin and epoxy resin, a combination of urethane resin and phenoxy resin, a combination of acrylic rubber and phenoxy resin, a combination of acrylic rubber and epoxy resin, and the like. Examples of the component having a skeleton that is easily aligned include a component containing an alkyl chain, a component containing a phenyl group, and the like. The inventors of the present invention believe that by the adhesive composition containing the above-mentioned components, the cured product (circuit connection member 4) of the obtained adhesive composition has a reduction in microscopic voids and molecular chains caused by a rise in temperature. The rearrangement of the filler, the rearrangement of the filler components, etc., produce shrinkage (volume phenomenon) accompanying temperature rise.

In one embodiment, the adhesive composition 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 include polyimide resins, polyamide resins, phenoxy resins, poly(meth)acrylic resins, polyester resins, and polyurethanes. One or two or more resins among 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 the desired linear thermal expansion, the adhesive composition preferably contains two or more of the thermoplastic resins, and more preferably contains Two or more types of thermoplastic resins having different Tgs from each other. As a combination of suitable resins, for example, a combination of a phenoxy resin and a poly(meth)acrylic resin, a combination of a phenoxy resin and a polyester resin, a phenoxy resin and a polyester urethane resin The combination of phenoxy resin and A combination of polyimide resins.

When the adhesive composition contains two or more thermoplastic resins with different Tg, it is more advantageous from the viewpoint that it is easy to obtain a cured product of the adhesive composition (circuit connection member 4) having a desired linear thermal expansion amount. The ratio of the content of the thermoplastic resin with high Tg to the thermoplastic resin with lower Tg (mass ratio: high Tg/low Tg) is preferably 90/10 to 10/90, more preferably 90/10 to 20/80 , More preferably 90/10~30/70. In the case where the adhesive composition contains three or more thermoplastic resins with different Tg, 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 is the ratio Contains more than the way.

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 still more preferably 150,000 or less. If the weight average molecular weight of the thermoplastic resin is 5000 or more, the adhesive force of the adhesive composition tends to increase. If the weight average molecular weight of the thermoplastic resin is 400,000 or less, it has excellent compatibility with other components and tends to improve the fluidity of the adhesive. 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 (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, 1,2-polybutadiene oak Glue, carboxyl-terminated 1,2-polybutadiene rubber, hydroxy-terminated 1,2-polybutadiene rubber, styrene-butadiene rubber, hydroxy-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 side chain group or terminal group as a highly polar group. These rubber components can be used alone or in combination of two or more.

The rubber component may also be in the form of particles. The average particle diameter of the rubber particles is preferably twice the average particle diameter of the conductive particles 10 or less, 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, 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.

With respect to 100 parts by mass of the total amount of (a) component and (b) component, the content of (a) component is preferably 20 parts by mass or more, more preferably 30 parts by mass or more, and still more preferably 35 parts by mass or more. In addition, 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. If the content of (a) component is 20 parts by mass or more, the adhesive strength is further improved, and the film formability of the adhesive composition tends to be improved, and if it is 80 parts by mass or less, the fluidity of the adhesive may be improved. tendency.

(b) The component is not particularly limited. For example, the compound (monomer) described below may be the compound (monomer), the oligomer of the compound may be used, or both may be contained.

The component (b) is preferably a polyfunctional (meth)acrylate compound having two or more (meth)acryloxy groups. Examples of such (meth)acrylate compounds include epoxy (meth)acrylate, urethane (meth)acrylate, polyether (meth)acrylate, and polyester (meth)acrylate. Polyalkylene glycol di(meth)acrylate such as acrylate, trimethylolpropane tri(meth)acrylate, polyethylene glycol di(meth)acrylate; dicyclopentenyl(methyl) )Acrylate, dicyclopentenoxyethyl (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 the two glycidyl groups of bisphenol diglycidyl ether, and (methyl) ) A compound in which propylene oxy group is introduced to two glycidyl groups of bisphenol diglycidyl ether to which ethylene glycol and/or propylene glycol are added. 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 can be used alone or in combination of two or more.

From the viewpoint of fluidity adjustment, etc., the adhesive composition may contain a monofunctional (meth)acrylate compound as the (b) component. Examples of monofunctional (meth)acrylate compounds include pentaerythritol (meth)acrylate, 2-cyanoethyl (meth)acrylate, cyclohexyl (meth)acrylate, and dicyclopentenyl (Meth)acrylate, dicyclopentenoxyethyl (meth)acrylate, 2-(2-ethoxyethoxy)ethyl (meth)acrylate, 2-ethoxyethyl (Meth) acrylate, 2-ethylhexyl (meth) acrylate, n-hexyl (meth) acrylate, 2-hydroxyethyl (meth) propylene Acid ester, hydroxypropyl (meth)acrylate, isobornyl (meth)acrylate, isodecyl (meth)acrylate, isooctyl (meth)acrylate, n-undecyl (meth)acrylate, Base) acrylate, 2-methoxyethyl (meth)acrylate, 2-phenoxyethyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, 2-(methyl) Acrylic oxyethyl phosphate, N,N-dimethylaminoethyl (meth)acrylate, N,N-dimethylaminopropyl (meth)acrylate, by using (former (Meth)acrylic acid and (meth)acryloyl morpholine obtained by reacting one glycidyl group of an epoxy resin having a plurality of glycidyl groups with acrylic acid. These compounds can be used alone or in combination of two or more.

From the viewpoint of improvement of 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 the (b) component. 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-dimethylacrylamide, N-isopropylacrylamide and N,N-diethyl Allyl amide.

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 phosphate structure may be, for example, a compound represented by the following formula (1), formula (2), or formula (3).

[化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 1-8. A plurality of R ¹ , R ² , a, and b in the same molecule may be the same as or different from each other.

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

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 1-8. A plurality of R ⁴ , R ⁵ , 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 structure include acidic phosphooxyethyl (meth)acrylate, acidic phosphooxypropyl (meth)acrylate, and acidic phosphooxypolyoxyethylene diacrylate. Alcohol mono(meth)acrylate, acid phosphooxypolyoxypropylene glycol mono(meth)acrylate, 2,2'-bis(meth)acryloxydiethyl phosphate, ethylene oxide (ethylene oxide) Oxide, EO) modified phosphoric acid di(meth)acrylate, phosphoric acid modified epoxy (meth)acrylate and vinyl phosphate.

With respect to 100 parts by mass of the total amount of (a) component and (b) component, the content of (b) component 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 or more, and 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. If the content of component (b) is 20 parts by mass or more, the heat resistance of the cured product (circuit connection member 4) of the adhesive composition tends to increase, and if it is 80 parts by mass or less, it is possible to further suppress high temperature and high humidity. The tendency of the circuit connection member 4 to peel off under the environment.

When the adhesive composition contains a radically polymerizable compound having a phosphate ester structure as the component (b), a radical having a phosphate ester structure relative to 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, more preferably 10 parts by mass or less. If it has a free phosphate structure When the content of the base polymerizable compound is 0.1 parts by mass or more, the adhesive strength of the adhesive composition tends to further increase. If it is 15 parts by mass or less, it is difficult to produce a cured product of the adhesive composition (circuit connection member 4 ) Tends to decrease physical properties and increase reliability.

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

The radical polymerization initiator can be, for example, one or more compounds selected from the following compounds: 1,1,3,3-tetramethylbutylperoxyneodecanoate, bis(4-tertiarybutylcyclohexyl) ) Peroxydicarbonate, bis(2-ethylhexyl)peroxydicarbonate, cumyl peroxide neodecanoate, dilaurin peroxide, 1-cyclohexyl-1-methyl ethyl neodecyl peroxide Esters, tertiary hexyl peroxy neodecanoate, tertiary butyl peroxy neodecanoate, tertiary butyl peroxy pivalate, 1,1,3,3-tetramethylbutyl peroxy -2-ethylhexanoate, 2,5-dimethyl-2,5-bis(2-ethylhexylperoxy)hexane, third hexylperoxy-2-ethylhexanoate, Tert-butylperoxy-2-ethylhexanoate, tert-butylperoxyneoheptanoate, tert-pentylperoxy-2-ethylhexanoate, di-tert-butylperoxide Hydrogen terephthalate, tert-pentylperoxy-3,5,5-trimethylhexanoate, 3-hydroxy-1,1-dimethylbutylperoxyneodecanoate, 1, 1,3,3-Tetramethylbutylperoxy-2-ethylhexanoate, tert-pentylperoxyneodecanoate, tert-pentylperoxy-2-ethylhexyl Ester, 3-methylbenzyl peroxide, 4-methylbenzyl peroxide, bis(3-methylbenzyl) peroxide, dibenzyl peroxide , Bis(4-methylbenzyl) peroxide, 2,2'-azobis-2,4-dimethylvaleronitrile, 1,1'-azobis(1-acetoxy) -1-phenylethane), 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), dimethyl-2,2'-azobis Isobutyronitrile, 4,4'-azobis(4-cyanovaleric acid), 1,1'-azobis(1-cyclohexanecarbonitrile), third hexylperoxy isopropyl monocarbonate , Tert-butylperoxymaleic acid, tert-butylperoxy-3,5,5-trimethylhexanoate, tert-butylperoxylaurate, 2,5-dimethyl- 2,5-bis(3-methylbenzylperoxy)hexane, tertiary butylperoxy-2-ethylhexyl monocarbonate, tertiary hexylperoxybenzoate, 2,5- Dimethyl-2,5-bis(benzylperoxy)hexane, tertiary butylperoxybenzoate, dibutylperoxytrimethyl adipate, tertiary amyl peroxide N-octanoate, tertiary amyl peroxy isononanoate and tertiary amyl peroxybenzoate.

From the viewpoint of suppressing 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 that the amount of organic acid generated after decomposition is less. The free radical polymerization initiator. From the standpoint of improving the stability of the adhesive composition, it is preferable to initiate radical polymerization with a mass retention rate of 20% by mass or more after being left in the atmosphere at room temperature (25°C) and atmospheric pressure for 24 hours. Agent.

The content of (c) component 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 (a) component and (b) component, and more preferably It is 15 parts by mass or less, more preferably 10 parts by mass 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 Is "(e) component"). The component (a) in this embodiment is the same component as the component (a) described in the above embodiment.

(d) The epoxy resin is a resin having at least one epoxy group in the molecule. Examples of epoxy resins include bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, phenol novolac type epoxy resins, cresol novolac type epoxy resins, and bisphenol novolac type epoxy resins. Novolac type epoxy resin, bisphenol F novolac type epoxy resin, cycloaliphatic epoxy resin, glycidyl ester type epoxy resin, glycidylamine type epoxy resin, hydantoin type epoxy resin , Isocyanurate type 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 can be used alone or in combination of two or more.

The content of (d) component in the adhesive composition is preferably 10 parts by mass or more, more preferably 20 parts by mass or more, and even more preferably 30 parts by mass relative to 100 parts by mass of the total amount of (a) component and (d) component Parts by mass or more, 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. If the content of the component (d) is 10 parts by mass or more, better adhesiveness tends to be obtained, and if it is 90 parts by mass or less, the viscosity is small and workability tends to become better.

(e) The hardener (also referred to as "epoxy polymerization initiator" or "latent hardener") should just be a hardener that can harden (d) epoxy resin. As hard Examples of the curing agent include anionic polymerizable catalyst type curing agents, cation polymerizable catalyst type curing agents, addition polymerization type curing agents, and the like. These can be used individually by 1 type or in combination of 2 or more types. From the viewpoint of excellent rapid curing properties and no need to consider chemical equivalents, (e) the curing agent is preferably an anionic polymerizable or cationic polymerizable catalyst-type curing agent.

Examples of anionic polymerizable or cationic polymerizable catalyst-type curing agents include imidazole-based curing agents, hydrazine-based curing agents, onium salts such as boron trifluoride-amine complexes, sulfonium salts, and diazonium salts, Aminimide, diaminomaleonitrile, melamine and its derivatives, salts of polyamines, dicyandiamine, etc., and these modified substances can also be used.

In the case of using compounds with tertiary amine groups, imidazole compounds, etc. as anionic polymerizable catalyst-type hardeners, epoxy resins are 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. As the cationically polymerizable catalyst-type curing agent, for example, a photosensitive onium salt (aromatic diazonium salt, aromatic sulfonium salt, etc.) that hardens an epoxy resin by energy ray irradiation can be preferably used. Examples of the cationic polymerizable catalyst-type curing agent that is activated by heating and cures the epoxy resin include aliphatic sulphur salts and the like. In terms of having rapid hardening properties, these anionic polymerizable or cationically polymerizable catalyst-type hardeners can be preferably used.

Examples of addition polymerization type hardeners include polyamines, polythiols, polyphenols, and acid anhydrides.

In terms of obtaining a longer usable time, it is preferable to coat them with polymer compounds such as polyurethane and polyester, metal thin films such as nickel and copper, and inorganic substances such as calcium silicate. Hardener (latent hardener) and microencapsulated hardener.

The content of (e) component in the adhesive composition is preferably 20 parts by mass or more, more preferably 30 parts by mass or more, with respect to 100 parts by mass of the total amount of (a) component and (d) component, 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 particles 10 may be coated conductive particles, which include: a core containing particles such as non-conductive glass, ceramics, plastics, etc.; and a layer made of the metal, metal particles, and conductive carbon particles that coat the core Wait. When the conductive particles 10 are coated conductive particles or metal particles that are melted by heat (hot-melt metal particles), the conductive particles 10 are deformed by heating and pressing during 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 is also increased, so that good reliability can be obtained. Especially when the amount of the conductive particles 10 is increased, the conductive particles 10 are prevented from short-circuiting each other, and the adjacent first circuit electrode 6, the first circuit electrode 6, or the second circuit electrode 8, the second circuit is raised. From the viewpoint of the insulation between the electrodes 8, the conductive particles 10 may be an insulating coating including the conductive particles and an insulating coating layer formed of an insulating material such as a polymer resin and covering the surface of the conductive particles. particle. These conductive particles, coated conductive particles, and insulating coated conductive particles can be used singly Or use a 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. If the content is 0.1% by volume or more, the conductivity tends to be further improved. If the content is 30% by volume or less, it is possible to suppress the adjacent first circuit electrode 6, the first circuit electrode 6, or the second circuit electrode 8, the second circuit electrode 8. The tendency of short circuit 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. For the volume of each component, for example, a value converted into a volume by weight using specific gravity can be used. In addition, for example, an appropriate solvent (water, alcohol, etc.) that sufficiently wets the component without dissolving or swelling the component may be added to a graduated cylinder, etc., and the component may be added and the volume increased as the volume. And find 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 Phenolic resins, melamine resins and other resins, fillers (fillers), softeners, hardening accelerators, anti-aging agents, colorants, flame retardants, thixotropic agents, coupling agents and other adhesion promoters, thickeners, and leveling Agents, weather resistance enhancers, isocyanate compounds, etc.

The filler (filler) can 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 conductive particles 10 The average particle size of the particle size is 1/2 or less, 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 characteristics such as the connection reliability between the circuit electrodes 6 and the circuit electrodes 8 by the cured product (circuit connection member 4) of the adhesive composition having the desired amount of linear thermal expansion, the filler is more It is preferably a filler with a negative average linear thermal expansion coefficient at 30°C to 120°C. As the filler whose average linear thermal expansion coefficient at 30°C to 120°C is negative, for example, particles composed of a zirconium compound can be cited.

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. If the content is 60 parts by mass or less, the effect of improving connection reliability tends to be more fully obtained, and if it is 5 parts by mass or more, there is a tendency to fully obtain the effect of filler addition.

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. As the silane coupling agent, for example, vinyl trimethoxy silane, vinyl triethoxy silane, 3-glycidoxy propyl trimethoxy silane, 3-glycidoxy propyl methyl diethoxy 3-(meth)acryloxypropylmethyldimethoxysilane, 3-(meth)acryloxypropyltrimethoxysilane, 3-(meth)acryloxypropylmethyldimethoxysilane, 3-(meth)acryloxypropylmethyldimethoxysilane Propylmethyldiethoxysilane, 3-(meth)acryloxypropyltriethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxy Silane, N-phenyl-3-aminopropyltrimethoxysilyl Alkane, 3-ureidopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-isocyanatepropyltriethoxysilane, and condensates of these.

The content of the coupling agent is preferably 0.1 parts by mass or more, more preferably 0.25 parts by mass or more with respect to 100 parts by mass of the adhesive components (for example, component (a) to (e)) of the adhesive composition, and more preferably 10 parts by mass or less, more preferably 5 parts by mass or less. If the content of the coupling agent is 0.1 parts by mass or more, there is a tendency to further suppress the occurrence of peeling between the circuit member and the circuit connection member, and if the content of the coupling agent is 10 parts by mass or less, there is a usable time of the adhesive composition The tendency to grow longer.

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 it can be used as a paste adhesive composition by dissolving in a solvent. The solvent is not particularly limited as long as it is non-reactive with the components of the adhesive composition and exhibits sufficient solubility for the components of the adhesive composition. The boiling point at atmospheric pressure is 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 the use in an open system becomes easy. In the case where the boiling point is 150°C or lower, the solvent is likely to volatilize after applying the adhesive composition 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 in which a solvent or the like is added to the adhesive composition as needed is applied to a release substrate such as a fluororesin film, a polyethylene terephthalate film, a release paper, or the like. Non-woven fabrics and other substrates are impregnated with the solution and placed on the peelable substrate, after which the solvent, etc. It is removed and shaped into a film. From the viewpoint of workability and the like, a film-like adhesive is suitably 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 material for CSP, communication Line of communication (LOC) tape and other semiconductor device bonding materials are represented.

The connection structure 1 can be obtained, for example, by arranging the first circuit member 2 and the second circuit member 3 such that the first circuit electrode 6 and the second circuit electrode 8 are opposed to each other, and the film-shaped adhesive is interposed between the first circuit member 2 and the second circuit member 3. Between the one circuit member 2 and the second circuit member 3, heating and pressurizing these are applied 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 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, from the viewpoint of connection at a lower temperature and in a short time, light irradiation can be performed simultaneously with heating and pressurization. The light irradiation preferably uses irradiation light in the wavelength range of 150 nm to 750 nm. The 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, and the irradiation amount is ^{0.1 J/cm 2} to 10 J/cm ^2.

The cured product (circuit connection member 4) of the adhesive composition described above is, for example, as shown by L1 in FIG. 2, and dl exists at a temperature of t=30°C to 120°C (t)/dt<0 (dL(t)/dt<0) t-like hardened material (circuit connection member), so the thermal expansion of the circuit connection member 4 itself due to temperature rise can be reduced, and it is possible to make the circuit Interfacial stress caused by peeling at the interface between the connection member 4 and the substrate 5, the substrate 7, the circuit electrode 6, and the circuit electrode 8 )reduce.

On the other hand, the cured product (circuit connection member) of the conventional adhesive composition, for example, as shown by L2 in FIG. 2, is always dl(t)/dt≧0( dL(t)/dt≧0) is a cured product (circuit connection member) of the adhesive composition. Therefore, as the temperature rises, the circuit connection member 4 itself is prone to thermal expansion. And the interface between the circuit electrode 6 and the circuit electrode 8 generates a large peeling interface stress.

Therefore, compared with the cured product (circuit connection member) of the conventional adhesive composition, the cured product (circuit connection member 4) of the adhesive composition of the present embodiment can even be placed in a high-temperature and high-humidity environment. It is also possible to suppress peeling of the circuit connection member 4 from the substrate 5, the substrate 7, the circuit electrode 6, and the circuit electrode 8. Such an effect can also be exhibited in the case of using circuit electrodes formed of amorphous ITO which is not conducive to adhesion as the circuit electrodes 6 and the circuit electrodes 8.

[Example]

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

<Synthesis of Polyurethane Resin>

In a separable flask equipped with a reflux cooler, a thermometer and a stirrer, add 1000 parts by mass of polypropylene glycol (number average molecular weight: 2000) as a glycol having an ether bond and 4000 parts by mass of methyl ethyl ketone as a solvent were added, and the mixture was stirred at 40°C for 30 minutes. After raising the temperature of this solution to 70°C, 0.127 parts by mass of dibutyltin laurate as a catalyst was added. 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 the absorption peak derived from the NCO group could not be observed by an infrared spectrophotometer, thereby obtaining a methyl ethyl ketone solution of a polyurethane resin. In addition, the amount of methyl ethyl ketone was adjusted so that the solid content concentration (concentration of the polyurethane resin) of the solution became 30% by mass.

The glass transition temperature (Tg) of the obtained polyurethane resin was -20°C. The glass transition temperature (Tg) is 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). Below, the analysis conditions of GPC are shown in Table 1.

<Synthesis of Urethane Acrylate>

In a 2L 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) were added. -238 parts by mass of 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 liquid. To the reaction liquid heated to 70° C., 666 parts by mass of isophorone diisocyanate (IPDI) was uniformly added dropwise over 3 hours to allow the reaction to proceed. After the dropwise addition is completed, the reaction is continued for 15 hours, and the reaction is terminated when the content of the NCO group becomes 0.2% by mass or less using a potential difference automatic titration device (product name AT-510, manufactured by Kyoto Electronics Industry Co., Ltd.) to obtain an amine Alkyl formate acrylate. The weight average molecular weight of the urethane acrylate is 8,500. In addition, the weight average molecular weight of urethane acrylate is measured similarly to the weight average molecular weight of the said polyurethane resin.

<Production of Film Adhesive>

The components shown below were mixed at the mass ratio shown in Table 2 and Table 3 to obtain an adhesive composition.

(Thermoplastic resin)

A1: Phenoxy resin (product name: PKHC, manufactured by Union Carbide, weight average molecular weight 45,000, Tg: 90°C, bisphenol A skeleton)

A2: Phenoxy resin (product name: YD-6020, manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., weight average molecular weight 5000, Tg: 70°C, bisphenol A/bisphenol F skeleton)

A3: Phenoxy resin (product name: FX-316, Nippon Steel & Sumikin Chemical Co., Ltd. has 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 & Sumikin Chemical Co., Ltd., Tg: 160°C, high heat resistance frame)

A5: Polyurethane resin synthesized as 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: Isocyanuric acid EO modified diacrylate (product name: M-215, manufactured by Toagosei Co., Ltd.)

B3: 2-methacryloxyethyl phosphate (product name: Light Ester P-2M, manufactured by Kyoeisha Chemical Co., Ltd.)

In addition, among the above components, the solid component was used on the basis of a 40% by mass solution prepared by dissolving 40 g of the solid component in 60 g of methyl ethyl ketone.

(Free radical polymerization initiator)

C1: Peroxy Laurel (product name: PEROYL L, manufactured by NOF Corporation, molecular weight 398.6)

(Filler (filler))

D1: Silica particles (product name: R104, Aerosil) Manufactured by Co., Ltd., primary particle size: 12nm)

(Silane coupling agent)

E1: 3-methacryloxypropyltrimethoxysilane (product name: KBM-503, manufactured by Shin-Etsu Chemical Co., Ltd.)

In addition, regarding the silica fine particles, a 10% by mass dispersion prepared by dispersing 10 g of the silica fine particles in a mixed solvent of 45 g of toluene and 45 g of ethyl acetate was used.

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 prepared on the surface of the polystyrene particles (core). The conductive 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 liquid was coated on a polyethylene terephthalate (PET) film with a thickness of 50 μm. The coating film was dried with hot air at 70°C for 10 minutes to obtain a film-like adhesive with a thickness of 18 μm.

<Production of Linked Structure>

On a flexible printed circuit (FPC) and glass (SiO ₂ ) substrate (product name: Pleikelin ( PreClean) slide glass S7224, manufactured by Songnang Glass Industry Co., Ltd.), or a glass substrate with a thin film of amorphous indium tin oxide (ITO) (manufactured by Geomatec). , Connect FPC to glass substrate or 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.), heating and pressurizing at 160° C. and 3 MPa for 5 seconds. The pressure during pressurization is calculated by setting the pressure-bonding area to 0.495 cm ^2. Thereby, it is possible to obtain a connected structure in which the FPC and the glass substrate or the glass substrate with amorphous ITO are connected by the cured product of the film-like adhesive across a width of 1.5 mm.

<Measurement of Linear Thermal Expansion>

A laminator was used to laminate a plurality of the film-like adhesives produced so that the thickness became 100±20 μm, and heated at 180° C. for 1 hour in an oven to produce a cured product sample. Regarding the cured product sample, a thermomechanical analysis device (manufactured by Shimadzu Corporation) was used. The length of the sample was 10mm and the width was 4mm, the load was 5gf (each 0.4mm ^{2 of the} sample's cross-sectional area), and the heating rate was 5°C/ Under the condition of minutes, measure the linear thermal expansion l(t)μm at a temperature t=0°C to 200°C every 0.1°C. The amount of linear thermal expansion l(t) is measured by setting the amount of linear thermal expansion l(0) at a temperature t=0°C to 0 μm. According to the measurement results, confirm whether there is a temperature range of dl(t)/dt<0 at a temperature of t=30°C to 120°C (if there is, confirm the temperature range and the minimum value of dl(t)/dt). In addition, the average linear thermal expansion coefficient (ppm/°C) at 30°C to 120°C was calculated based on the measurement results. The results are shown in Table 2 and Table 3.

<Evaluation of presence or absence of peeling>

Regarding the connected structure produced in the above manner, an optical microscope was used to observe the appearance of the connection immediately after the connection and after a high temperature and high humidity test placed in a constant temperature and humidity bath at 85°C and 85% RH for 250 hours, and the space portion was measured ( The area between the electrode terminal and the electrode terminal of the FPC where the peeling of the substrate-resin interface occurs. Will space The case where the total peeling occurrence area exceeded 30% was evaluated as "existing" peeling, and the case where 30% or less was evaluated as "no" peeling. The results are shown in Table 2 and 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: The first circuit component

3: The second circuit component

4: Circuit connection member

5: The first substrate

6: The first circuit electrode

7: Second substrate

8: second circuit electrode

9: Hardened material of the adhesive component

10: Conductive particles

Claims (6)

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 Between, the first circuit electrode and the second circuit electrode are electrically connected to each other, and the circuit connection member is an adhesive composition including two or more types of thermoplastic resins having mutually different glass transition temperatures. The linear thermal expansion amount L(t) of the circuit connection member at temperature t satisfies the condition of dL(t)/dt<0 at least any temperature t from t=30°C to 120°C. The connection structure according to the first item 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 is a cured product of an adhesive composition including two or more thermoplastic resins having mutually different glass transition temperatures, wherein the linear thermal expansion of the circuit connection member at a temperature t The quantity L(t) satisfies the condition of dL(t)/dt<0 at least at any temperature t from t=30°C to 120°C. The circuit connection member described in 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 including different glass transition temperatures Two or more thermoplastic resins, wherein the linear thermal expansion l(t) of the cured product of the adhesive composition at temperature t satisfies dl(t )/dt<0. The adhesive composition according to item 5 of the scope of 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.

Images