JP6958359B2 - Adhesive composition and structure - Google Patents

Description

The present invention relates to adhesive compositions and structures.

In semiconductor elements and liquid crystal display elements (display display elements), various adhesives have been conventionally used for the purpose of binding various members in the elements. The properties required for adhesives range from adhesiveness to heat resistance and reliability in high temperature and high humidity conditions. As the adherend to be used in the adhesive, the printed wiring board, organic substrates (e.g. polyimide substrate) or the like including the metal (titanium, copper, aluminum, _{etc.), ITO, IZO, IGZO,} SiN X, SiO _{A base material having a wide variety of surface states such as No. 2} is used, and it is necessary to design the molecule of the adhesive according to each adherend.

Conventionally, thermosetting resins (epoxy resins, acrylic resins, etc.) exhibiting high adhesiveness and high reliability have been used as adhesives for semiconductor elements or liquid crystal display elements. As a constituent component of the adhesive using an epoxy resin, an epoxy resin and a latent curing agent that generates a cationic species or an anionic species having reactivity with the epoxy resin by heat or light are generally used. The latent curing agent is an important factor that determines the curing temperature and the curing rate, and various compounds have been used from the viewpoint of storage stability at room temperature and curing rate at the time of heating. In the actual step, for example, the desired adhesiveness was obtained by curing under curing conditions of 170 to 250 ° C. for 10 seconds to 3 hours.

Further, in recent years, with the high integration of semiconductor elements and the high definition of liquid crystal display elements, the pitch between elements and between wirings has become narrower, and the heat during curing may adversely affect peripheral members. Further, in order to reduce the cost, it is necessary to improve the throughput, and adhesion at a low temperature (90 to 170 ° C.) and a short time (within 1 hour, preferably within 10 seconds, more preferably within 5 seconds) can be performed. It is required. In other words, adhesion by low temperature short time curing (low temperature fast curing) is required. In order to achieve this low-temperature short-time curing, it is necessary to use a thermal latent catalyst with low activation energy, but it is known that it is very difficult to combine storage stability near room temperature. ..

Therefore, in recent years, a radical curing adhesive or the like in which a (meth) acrylate derivative and a peroxide as a radical polymerization initiator are used in combination has attracted attention. In the radical curing system, radicals, which are reactive species, are extremely reactive, so that they can be cured in a short time, and peroxides are stably present below the decomposition temperature of the radical polymerization initiator. It is a curing system that achieves both low-temperature short-time curing and storage stability (for example, storage stability near room temperature).

However, in recent years, in the above-mentioned radical curing adhesive, there is a problem that peeling occurs at the interface between the adherend and the adhesive after high temperature and high humidity treatment (high temperature and high humidity test) such as 85 ° C. and 85% RH. It has become.

On the other hand, many attempts have been made so far to improve the adhesion (interfacial adhesion) at the interface between the adherend and the adhesive after the high-temperature and high-humidity treatment as described above and suppress the occurrence of peeling. (For example, see Patent Documents 1 to 6 below).

Japanese Unexamined Patent Publication No. 2007-177204 Japanese Unexamined Patent Publication No. 2010-1111846 Japanese Unexamined Patent Publication No. 2003-228637 Japanese Unexamined Patent Publication No. 2003-277649 JP-A-2009-256619 Japanese Unexamined Patent Publication No. 2013-191625

By the way, the adhesive composition used as an adhesive is required to further enhance the effect of suppressing peeling after high temperature and high humidity treatment.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an adhesive composition capable of suppressing peeling after a high-temperature and high-humidity treatment, and a structure using the same. ..

As a result of diligent studies by the present inventors, in order to suppress peeling after high temperature and high humidity treatment, the adhesive composition is a silane compound having a urethane bond and an alkoxysilyl group in the molecule, and the silane compound. It has been clarified that it is important to contain a compound having a urethane bond other than the above, and to have a low linear thermal expansion coefficient of the cured product of the adhesive composition.

More specifically, when the adhesive composition contains a silane compound having a urethane bond and an alkoxysilyl group, and a compound having a urethane bond different from the silane compound, the silane is described above. It has been found that the compound significantly improves the effect of improving peeling. Furthermore, the present inventors have found that the linear thermal expansion coefficient of the cured product tends to decrease by using these components, and then the average linear thermal expansion coefficient of the cured product at 30 to 90 ° C. is 800 ppm /. It was found that adjusting to K or less is effective in suppressing peeling after high temperature and high humidity treatment.

That is, the adhesive composition according to the present invention comprises (a) a thermoplastic resin (hereinafter, also sometimes referred to as “(a) component”), and (b) a silane compound having a urethane bond and an alkoxysilyl group in the molecule. (Hereinafter, sometimes referred to as "component (b)"), (c) radically polymerizable compound (hereinafter, also referred to as "component (c)" in some cases), and (d) radical polymerization initiator (hereinafter, case). (Also referred to as "(d) component"), and (a) component, (c) component, (d) component, or (a) component, (b) component, (c) component and (d) component. As a component other than, (e) a compound having a urethane bond (hereinafter, also referred to as “(e) component” in some cases) is contained, and the average radical thermal expansion coefficient of the cured product at 30 to 90 ° C. (hereinafter, simply “average”). (Also referred to as "radical expansion coefficient") is 800 ppm / K or less.

According to the adhesive composition according to the present invention, peeling after high temperature and high humidity treatment can be suppressed. It is presumed that such an effect of suppressing peeling is obtained by improving the interfacial adhesion after the high temperature and high humidity treatment. In addition, the present inventors have found that the adhesive composition according to the present invention has a long-lasting effect of improving peeling. That is, the adhesive composition according to the present invention is excellent in storage stability.

By the way, the causes of peeling after high-temperature and high-humidity treatment are insufficient reaction of the adhesive (insufficient curing) due to the short-time mounting at low temperature, and commoditization of display members such as smartphones, which causes adhesion inhibition. The number of adherends (display members, liquid crystal panels, etc.) whose surfaces are contaminated with easy and inexpensive substances is increasing, and they are more hydrophilic than silicon nitride, which is conventionally used for insulating films, and are treated at high temperature and high humidity. It is conceivable that the use of adherends (such as substrates such as plain glass) having a surface on which peeling is likely to occur later is increasing. On the other hand, according to the adhesive composition according to the present invention, even when such an adherend is used, peeling after high temperature and high humidity treatment can be suppressed.

The component (b) preferably further contains at least one selected from the group consisting of a (meth) acryloyl group and a vinyl group. As a result, peeling after high temperature and high humidity treatment can be further suppressed.

The component (e) preferably contains at least one selected from the group consisting of polyurethane, polyester urethane and urethane (meth) acrylate. As a result, peeling after high temperature and high humidity treatment can be further suppressed.

The content of the component (c) is preferably 20% by mass or more based on the total mass of the solid content in the adhesive composition. As a result, peeling after high temperature and high humidity treatment can be further suppressed.

The adhesive composition according to the present invention preferably further contains an inorganic filler having a primary particle size of 100 nm or less. As a result, peeling after high temperature and high humidity treatment can be further suppressed.

The structure according to the present invention includes the adhesive composition or a cured product thereof.

The structure according to the present invention includes a first circuit member having a first circuit electrode, a second circuit member having a second circuit electrode, the first circuit member, and the second circuit member. A circuit connecting member arranged between them is provided, and the first circuit electrode and the second circuit electrode are electrically connected to each other, and the circuit connecting member connects the adhesive composition or a cured product thereof. It may be an aspect including.

According to the present invention, it is possible to provide an adhesive composition capable of suppressing peeling after a high temperature and high humidity treatment, and a structure using the same.

According to the present invention, it is possible to provide an application of an adhesive composition or a cured product thereof to a structure or its production. According to the present invention, it is possible to provide an application of an adhesive composition or a cured product thereof to a circuit connection. According to the present invention, it is possible to provide an application of an adhesive composition or a cured product thereof to a circuit connection structure or its production.

It is a schematic cross-sectional view which shows one Embodiment of the structure which concerns on this invention. It is a schematic cross-sectional view which shows the other embodiment of the structure which concerns on this invention.

Hereinafter, embodiments of the present invention will be described, but the present invention is not limited to these embodiments.

As used herein, the term "(meth) acrylate" means at least one of an acrylate and a corresponding methacrylate. The same applies to other similar expressions such as "(meta) acryloyl" and "(meth) acrylic acid". Unless otherwise specified, the materials exemplified below may be used alone or in combination of two or more. The content of each component in the composition means the total amount of the plurality of substances present in the composition when a plurality of substances corresponding to each component are present in the composition, unless otherwise specified. The numerical range indicated by using "~" indicates a range including the numerical values before and after "~" as the minimum value and the maximum value, respectively. "A or B" may include either A or B, or both. "Room temperature" means 25 ° C.

In the numerical range described stepwise in the present specification, the upper limit value or the lower limit value of the numerical range of one step may be replaced with the upper limit value or the lower limit value of the numerical range of another step. Further, in the numerical range described in the present specification, the upper limit value or the lower limit value of the numerical range may be replaced with the value shown in the examples.

In the present specification, "adhesive strength", "adhesiveness", "adhesive strength" and "interfacial adhesion" are synonymous with each other. For example, high adhesive strength after high temperature and high humidity treatment means high interfacial adhesion after high temperature and high humidity treatment. In the present specification, "the total mass of the solid content in the adhesive composition" means the total mass of the adhesive composition when the adhesive composition does not contain a solvent, and the adhesive composition means the total mass of the adhesive composition. When it contains a solvent, it means the mass after subtracting the mass of the solvent from the total mass of the adhesive composition. When the adhesive composition contains conductive particles, the "total mass of solids in the adhesive composition" does not include the mass of conductive particles, and the "total volume of solids in the adhesive composition" is Does not include the volume of conductive particles (ie, "total mass of solids in the adhesive composition" means "total mass of solids (excluding conductive particles) in the adhesive composition", " "Total volume of solids in the adhesive composition" means "total volume of solids (excluding conductive particles) in the adhesive composition").

<Adhesive composition>
The adhesive composition according to the present embodiment includes (a) a thermoplastic resin, (b) a silane compound having a urethane bond and an alkoxysilyl group in the molecule, (c) a radically polymerizable compound, and (d) a radical. It contains a polymerization initiator and contains (e) as a component other than the component (a), the component (c), the component (d), or the component (a), the component (b), the component (c) and the component (d). ) Contains a compound having a urethane bond. The adhesive composition according to this embodiment is, for example, a radical curing adhesive composition.

[(A) component]
Examples of the component (a) include at least one resin selected from the group consisting of polyimide, polyamide, phenoxy resin, (meth) acrylic resin, polyester, polyurethane, polyester urethane, polyether urethane and polyvinyl butyral. As the component (a), one type can be used alone or two or more types can be used in combination.

The component (a) preferably contains a phenoxy resin from the viewpoint of further suppressing peeling after the high temperature and high humidity treatment. Similarly, the component (a) preferably contains a thermoplastic resin having a urethane bond from the viewpoint of further suppressing peeling after the high temperature and high humidity treatment. Examples of such a thermoplastic resin include polyurethane, polyester urethane, and polyether urethane.

As the component (a), a rubber component can also be used for the purpose of stress relaxation and further improvement of adhesiveness after high temperature and high humidity treatment. Examples of the rubber component include acrylic rubber, polyisoprene, polybutadiene, carboxyl group-terminated polybutadiene, hydroxyl group-terminated polybutadiene, 1,2-polybutadiene, carboxyl group-terminated 1,2-polybutadiene, hydroxyl group-terminated 1,2-polybutadiene, and styrene-butadiene. Examples include rubber, hydroxyl group-terminated styrene-butadiene rubber, carboxylated nitrile rubber, hydroxyl group-terminated poly (oxypropylene), alkoxysilyl group-terminated poly (oxypropylene), poly (oxytetramethylene) glycol, polyolefin glycol and poly-ε-caprolactone. Be done. The rubber component preferably has a cyano group or a carboxyl group, which are highly polar groups, as side chain groups or terminal groups from the viewpoint of further improving the adhesiveness after the high temperature and high humidity treatment. As the rubber component, one type can be used alone or two or more types can be used in combination.

The weight average molecular weight (Mw) of the component (a) is preferably 5000 or more, and more preferably 10,000 or more, from the viewpoint of further improving the adhesive force of the adhesive composition. The weight average molecular weight (Mw) of the component (a) is preferably 1,000,000 or less from the viewpoint that good compatibility with other components tends to be easily obtained and suitable fluidity of the adhesive composition can be easily obtained. , 500,000 or less is more preferable, and 400,000 or less is further preferable. From these viewpoints, the weight average molecular weight of the component (a) is preferably 5000 to 1,000,000, more preferably 5000 to 500000, and even more preferably 1000 to 400000.

The weight average molecular weight can be measured by, for example, gel permeation chromatography (GPC) using a standard polystyrene calibration curve. More specifically, the measurement can be performed under the conditions described in the examples.

The content of the component (a) is the total amount of the components (a) and (c) 100 from the viewpoint of further improving the adhesive strength of the adhesive composition and improving the film-forming property of the adhesive composition. With respect to parts by mass, 20 parts by mass or more is preferable, 30 parts by mass or more is more preferable, and 35 parts by mass or more is further preferable. The content of the component (a) is preferably 80 parts by mass or less with respect to 100 parts by mass of the total amount of the components (a) and (c) from the viewpoint that suitable fluidity of the adhesive composition can be easily obtained. 70 parts by mass or less is more preferable, and 65 parts by mass or less is further preferable. From these viewpoints, the content of the component (a) is preferably 20 to 80 parts by mass, more preferably 30 to 70 parts by mass, and 35 parts by mass with respect to 100 parts by mass of the total amount of the components (a) and (c). ~ 65 parts by mass is more preferable.

As described above, the component (a) may contain a thermoplastic resin having a urethane bond. In other words, the component (a) may contain the component (e). When the component (a) contains the component (e), the content C _{a1 of the} component (a) having a urethane bond is the component (a) and (c) from the viewpoint of further suppressing peeling after the high temperature and high humidity treatment. ) The following range is preferable with respect to 100 parts by mass of the total amount of the components. The content C _a1 is preferably 20 parts by mass or more, more preferably 30 parts by mass or more, and further preferably 35 parts by mass or more. The content C _a1 is preferably 80 parts by mass or less, more preferably 70 parts by mass or less, and further preferably 65 parts by mass or less. From these viewpoints, the content _{C a1} is preferably 20 to 80 parts by weight, more preferably 30 to 70 parts by weight, more preferably 35 to 65 parts by weight.

[(B) component]
The adhesive composition according to the present embodiment contains a silane compound having a urethane bond and an alkoxysilyl group in the molecule as the component (b). As the component (b), one type can be used alone or two or more types can be used in combination.

The component (b) may be a compound having a urethane bond and an alkoxysilyl group having 1 to 2 carbon atoms exhibiting hydrolyzability in the molecule. As the component (b), a compound represented by the following formula (1) is preferable from the viewpoint of further suppressing exfoliation after the high temperature and high humidity treatment.

［式（１）中、ｍは１〜３の整数を示し、Ｒ^１１は水素原子、メチル基又はエチル基を示し、Ｒ^１２は任意の１価の有機基を示し、Ｒ^１３は任意の２価の有機基を示す。同一分子中の複数のＲ^１１は同一でも異なっていてもよい。］

[In formula (1), m represents an integer of 1 to 3, R ¹¹ represents a hydrogen atom, a methyl group or an ethyl group, R ¹² represents an arbitrary monovalent organic group, and R ¹³ represents an arbitrary 2 Indicates a valent organic group. A plurality of R ¹¹ in the same molecule may be the same or different. ]

The component (b) preferably further has a reactive functional group from the viewpoint of further suppressing exfoliation after the high temperature and high humidity treatment. That is, as the component (b), an alkoxysilane compound having a reactive functional group and a urethane bond in the molecule is preferable. For example, when the component (b) is a compound represented by the formula (1), R ¹² is preferably an organic group having a reactive functional group. The reactive functional group may be at least one functional group selected from the group consisting of (meth) acryloyl group and vinyl group from the viewpoint of further suppressing exfoliation after high temperature and high humidity treatment. R ¹³ may be a group represented by the following formula.

［式中、ｎは任意の整数を示す。］

[In the formula, n represents an arbitrary integer. ]

m is preferably 2 or 3 and more preferably 3 from the viewpoint of further suppressing peeling after the high temperature and high humidity treatment. n is preferably 0 to 15, more preferably 1 to 10, and even more preferably 1 to 5 from the viewpoint of further suppressing peeling after the high temperature and high humidity treatment.

Specific examples of the compound represented by the formula (1) include compounds represented by the following formulas (1a) to (1k). These compounds may be used alone or in combination of two or more. As the compound represented by the formula (1), a compound in which R ^1b is a hydrogen atom in the formula (1b) is preferable from the viewpoint of further suppressing exfoliation after the high temperature and high humidity treatment.

Here, R ^1a represents an alkyl group having 1 to 10 carbon atoms or a cyclic alkyl group. Each of R ^1b , R ^1c and R ^1d represents a hydrogen atom or a methyl group. Each of R ^1e , R ^11f , R ^1g , R ^1h , R ¹ⁱ and R ^1j represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a cyclic alkyl group, an alkoxy group, an acyl group or an acyloxy group. R ^12f represents an alkylene group having 1 to 3 carbon atoms. Et represents an ethyl group and Me represents a methyl group. p represents an integer of 1-5.

The content of the component (b) is an adhesive composition from the viewpoint that peeling after high temperature and high humidity treatment is further suppressed (for example, generation of peeling bubbles at the interface between the circuit member and the circuit connecting material is further suppressed). The following range is preferable based on the total mass of the solid content in the product. The content of the component (b) is preferably 0.2 parts by mass or more, more preferably 0.5 parts by mass or more, further preferably 1 part by mass or more, and particularly preferably 5 parts by mass or more. The content of the component (b) is preferably 30 parts by mass or less, more preferably 20 parts by mass or less, further preferably 15 parts by mass or less, and particularly preferably 10 parts by mass or less. From these viewpoints, the content of the component (b) is preferably 0.2 to 30 parts by mass, more preferably 0.5 to 20 parts by mass, further preferably 1 to 15 parts by mass, and 5 to 10 parts by mass. Especially preferable.

The content of the component (b) is preferably in the following range with respect to 100 parts by mass of the component (a) from the viewpoint of further suppressing peeling after the high temperature and high humidity treatment. The content of the component (b) is preferably more than 5 parts by mass, more preferably 7.5 parts by mass or more, further preferably 10 parts by mass or more, and particularly preferably 15 parts by mass or more. The content of the component (b) is preferably 100 parts by mass or less, more preferably 80 parts by mass or less, further preferably 60 parts by mass or less, particularly preferably 40 parts by mass or less, and extremely preferably 30 parts by mass or less. From these viewpoints, the content of the component (b) is preferably more than 5 parts by mass and 100 parts by mass or less, more preferably 7.5 to 80 parts by mass, further preferably 10 to 60 parts by mass, and 15 to 40 parts by mass. Parts are particularly preferable, and 15 to 30 parts by mass are extremely preferable.

[Ingredient (c)]
The adhesive composition according to the present embodiment may contain a radically polymerizable compound (excluding the compound corresponding to the component (b)) as the component (c). As the component (c), a monomer and / or an oligomer can be used.

The component (c) may be a radically polymerizable compound having two or more (meth) acryloyl groups in the molecule. As the component (c), a polyfunctional (meth) acrylate compound having two or more (meth) acryloyloxy groups in the molecule is preferable. In this case, the cohesive force after curing is sufficiently exhibited and the curing shrinkage is suppressed, so that the adhesiveness is further improved and the peeling after the high temperature and high humidity treatment tends to be further suppressed. Examples of such (meth) acrylate compounds include epoxy (meth) acrylate, urethane (meth) acrylate, polyether (meth) acrylate, polyester (meth) acrylate, trimethylpropantri (meth) acrylate, and polyalkylene glycol di (). Meta) acrylate (polyethylene glycol di (meth) acrylate, etc.), neopentyl glycol di (meth) acrylate, dipentaerythritol hexa (meth) acrylate, isocyanuric acid-modified bifunctional (meth) acrylate, isocyanuric acid-modified trifunctional (meth) Examples include acrylate. As the component (c), one type can be used alone or two or more types can be used in combination.

Epoxy (meth) acrylates include epoxy (meth) acrylate in which (meth) acrylic acid is added to the two glycidyl groups of bisphenol full orange glycidyl ether, and ethylene glycol and / or the two glycidyl groups of bisphenol full orange glycidyl ether. Examples thereof include epoxy (meth) acrylate in which a (meth) acryloyloxy group is introduced into a compound to which propylene glycol is added.

The component (c) preferably contains a radically polymerizable compound having two or more (meth) acryloyl groups in the molecule and having a urethane bond. In this case, the compatibility between the component (b) and the component (c) becomes good, and the peeling after the high temperature and high humidity treatment tends to be further suppressed. Examples of such a radically polymerizable compound include urethane (meth) acrylate.

The adhesive composition according to the present embodiment may contain a monofunctional (meth) acrylate compound as the component (c) for the purpose of adjusting the fluidity and the like.

Examples of the monofunctional (meth) acrylate compound include pentaerythritol (meth) acrylate, 2-cyanoethyl (meth) acrylate, cyclohexyl (meth) acrylate, dicyclopentenyl (meth) acrylate, and dicyclopentenyloxyethyl (meth). Acrylate, 2- (2-ethoxyethoxy) ethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-hexyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, Hydroxypropyl (meth) acrylate, isobornyl (meth) acrylate, isodecyl (meth) acrylate, isooctyl (meth) acrylate, n-lauryl (meth) acrylate, 2-methoxyethyl (meth) acrylate, 2-phenoxyethyl (meth) acrylate , Tetrahydrofurfreel (meth) acrylate, 2- (meth) acryloyloxyethyl phosphate, N, N-dimethylaminoethyl (meth) acrylate, N, N-dimethylaminopropyl (meth) acrylate, multiple glycidyl groups Examples thereof include glycidyl group-containing (meth) acrylate obtained by reacting (meth) acrylic acid with one of the glycidyl groups of the epoxy resin, and (meth) acryloylmorpholine. The monofunctional (meth) acrylate compound may be used alone or in combination of two or more.

The adhesive composition according to the present embodiment contains a compound having a radically polymerizable functional group such as an allyl group, a maleimide group, or a vinyl group as the component (c) for the purpose of improving the bridging rate and the like. May be good. Examples of such compounds include N-vinylimidazole, N-vinylpyridine, N-vinylpyrrolidone, N-vinylformamide, N-vinylcaprolactam, 4,4'-vinylidenebis (N, N-dimethylaniline), and the like. Examples thereof include N-vinylacetamide, N, N-dimethylacrylamide, N-isopropylacrylamide and N, N-diethylacrylamide.

The adhesive composition according to the present embodiment contains a radically polymerizable compound having a phosphoric acid group (hereinafter, also referred to as “(c1) component” in some cases) as the component (c) for the purpose of improving the adhesive strength. It is preferable to do so. Examples of the component (c1) include compounds represented by the following formula (2a), formula (2b) or formula (2c).

［式（２ａ）中、Ｒ^２１ａは水素原子又はメチル基を示し、Ｒ^２２ａは（メタ）アクリロイルオキシ基を示し、ｗ及びｘはそれぞれ独立に１〜８の整数を示す。なお、同一分子中の複数のＲ^２１ａ、Ｒ^２２ａ、ｗ及びｘはそれぞれ同一でも異なっていてもよい。］

[In formula (2a), R ^21a represents a hydrogen atom or a methyl group, R ^22a represents a (meth) acryloyloxy group, and w and x each independently represent an integer of 1-8. The plurality of R ^21a , R ^22a , w and x in the same molecule may be the same or different. ]

［式（２ｂ）中、Ｒ^２ｂは（メタ）アクリロイルオキシ基を示し、ｙ及びｚはそれぞれ独立に１〜８の整数を示す。同一分子中の複数のＲ^２ｂ、ｙ及びｚは、それぞれ同一でも異なっていてもよい。］

[In formula (2b), R ^2b represents a (meth) acryloyloxy group, and y and z each independently represent an integer of 1-8. The plurality of R ^2b , y and z in the same molecule may be the same or different. ]

［式（２ｃ）中、Ｒ^２１ｃは水素原子又はメチル基を示し、Ｒ^２２ｃは（メタ）アクリロイルオキシ基を示し、ｂ及びｃはそれぞれ独立に１〜８の整数を示す。同一分子中の複数のＲ^２１ｃ及びｂは同一でも異なっていてもよい。］

[In formula (2c), R ^21c represents a hydrogen atom or a methyl group, R ^22c represents a (meth) acryloyloxy group, and b and c each independently represent an integer of 1-8. The plurality of R ^21c and b in the same molecule may be the same or different. ]

Examples of the component (c1) include 2,2'-di (meth) acryloyloxydiethyl phosphate, EO (ethylene oxide) -modified di (meth) phosphate, acid phosphooxyethyl (meth) acrylate, and acid phosphooxy. Examples thereof include propyl (meth) acrylate, acid phosphooxypolyoxyethylene glycol mono (meth) acrylate, acid phosphooxypolyoxypropylene glycol mono (meth) acrylate, phosphoric acid-modified epoxy (meth) acrylate and vinyl phosphate.

From the viewpoint of improving heat resistance, the content of the component (c) 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 (c). 35 parts by mass or more is more preferable, 40 parts by mass or more is particularly preferable, and 45 parts by mass or more is extremely preferable. The content of the component (c) is preferably 80 parts by mass or less with respect to 100 parts by mass of the total amount of the components (a) and (c) from the viewpoint of further increasing the effect of suppressing peeling after the high temperature and high humidity treatment. , 70 parts by mass or less is more preferable, 65 parts by mass or less is further preferable, 60 parts by mass or less is particularly preferable, and 55 parts by mass or less is extremely preferable. From these viewpoints, the content of the component (c) is preferably 20 to 80 parts by mass, more preferably 30 to 70 parts by mass, and 35 parts by mass with respect to 100 parts by mass of the total amount of the components (a) and (c). ~ 65 parts by mass is more preferable, 40 to 60 parts by mass is particularly preferable, and 45 to 55 parts by mass is extremely preferable.

The content of the component (c1) is preferably 0.1 part by mass or more, preferably 0.5 part by mass, based on 100 parts by mass of the total amount of the component (a) and the component (c) from the viewpoint that high adhesive strength can be easily obtained. More than parts are more preferable, 1 part by mass or more is further preferable, and 2 parts by mass or more is particularly preferable. The content of the component (c1) is 100, from the viewpoint that the physical properties of the cured product of the adhesive composition are less likely to deteriorate and the effect of improving the connection reliability is satisfactorily obtained. With respect to parts by mass, 15 parts by mass or less is preferable, 10 parts by mass or less is more preferable, 5 parts by mass or less is further preferable, and 3 parts by mass or less is particularly preferable. From these viewpoints, the content of the component (c1) is preferably 0.1 to 15 parts by mass, preferably 0.5 to 10 parts by mass, based on 100 parts by mass of the total amount of the components (a) and (c). More preferably, 1 to 5 parts by mass is further preferable, and 2 to 3 parts by mass is particularly preferable.

The content of the component (c) is preferably 20% by mass or more, preferably 30% by mass or more, based on the total mass of the solid content in the adhesive composition, from the viewpoint of further suppressing peeling after the high temperature and high humidity treatment. Is more preferable, and 40% by mass or more is further preferable. The content of the component (c) is preferably 90% by mass or less, preferably 80% by mass or less, based on the total mass of the solid content in the adhesive composition, from the viewpoint of further suppressing peeling after the high temperature and high humidity treatment. Is more preferable, 70% by mass or less is further preferable, and 60% by mass or less is particularly preferable. From these viewpoints, the content of the component (c) is preferably 20 to 90% by mass, more preferably 30 to 80% by mass, and 40 to 70% by mass, based on the total mass of the solid content in the adhesive composition. % Is more preferable, and 40 to 60% by mass is particularly preferable.

As described above, the component (c) may contain a radically polymerizable compound having a urethane bond. In other words, the component (c) may contain the component (e). When the component (c) contains the component (e), the content C _{b1 of the} component (c) having a urethane bond is the component (a) and (c) from the viewpoint of further suppressing peeling after the high temperature and high humidity treatment. ) The following range is preferable with respect to 100 parts by mass of the total amount of the components. The content C _b1 is preferably 20 parts by mass or more, more preferably 30 parts by mass or more, and further preferably 40 parts by mass or more. The content C _b1 is preferably 90 parts by mass or less, more preferably 80 parts by mass or less, further preferably 70 parts by mass or less, particularly preferably 60 parts by mass or less, and extremely preferably 50 parts by mass or less. From these viewpoints, the content C _b1 is preferably 20 to 90 parts by mass, more preferably 30 to 80 parts by mass, further preferably 40 to 70 parts by mass, particularly preferably 40 to 60 parts by mass, and 40 to 50 parts by mass. Part is highly preferred.

When the component (c) contains the component (e), the mass ratio C _b1 / C _{b2 of the content C b1} to the content _{C b2} of the component (c) which does not have a urethane bond is peeled off after the high temperature and high humidity treatment. From the viewpoint of further suppression, the following range is preferable. The mass ratio C _b1 / C _b2 is preferably 0.01 or more, more preferably 0.1 or more, further preferably 1 or more, particularly preferably 2 or more, and extremely preferably 3 or more. The mass ratio C _b1 / C _b2 may be 50 or less.

[(D) component]
The adhesive composition according to the present embodiment contains a radical polymerization initiator as the component (d). The component (d) can be arbitrarily selected from compounds such as peroxides and azo compounds. As the component (d), a peroxide having a 1-minute half-life temperature of 90 to 175 ° C. and a molecular weight of 180 to 1000 is preferable from the viewpoint of excellent stability, reactivity and compatibility. The "1 minute half-life temperature" means a temperature at which the half-life of the peroxide is 1 minute. "Half-life" refers to the time it takes for the concentration of a compound to decrease to half its initial value at a given temperature. As the component (d), one type can be used alone or two or more types can be used in combination.

The component (d) is, for example, 1,1,3,3-tetramethylbutylperoxyneodecanoate, di (4-t-butylcyclohexyl) peroxydicarbonate, di (2-ethylhexyl) peroxydicarbonate. , Cumylperoxyneodecanoate, dilauroyl peroxide, 1-cyclohexyl-1-methylethylperoxyneodecanoate, t-hexylperoxyneodecanoate, t-butylperoxyneodecanoate, t -Butylperoxypivalate, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, 2,5-dimethyl-2,5-di (2-ethylhexanoylperoxy) hexane, t-Hexylperoxy-2-ethylhexanoate, t-butylperoxy-2-ethylhexanoate, t-butylperoxyneoheptanoate, t-amylperoxy-2-ethylhexanoate, di -T-Butylperoxyhexahydroterephthalate, t-amylperoxy-3,5,5-trimethylhexanoate, 3-hydroxy-1,1-dimethylbutylperoxyneodecanoate, t-amylperoxyneo Decanoate, 3-methylbenzoyl peroxide, 4-methylbenzoyl peroxide, di (3-methylbenzoyl) peroxide, dibenzoyl peroxide, di (4-methylbenzoyl) peroxide, 2,2'-azobis- 2,4-Dimethylvaleronitrile, 1,1'-azobis (1-acetoxy-1-phenylethane), 2,2'-azobisisobutyronitrile, 2,2'-azobis (2-methylbutyronitrile) ), 4,4'-azobis (4-cyanovaleric acid), 1,1'-azobis (1-cyclohexanecarbonitrile), t-hexylperoxyisopropyl monocarbonate, t-butylperoxymaleic acid, t-butylper Oxy-3,5,5-trimethylhexanoate, t-butylperoxylaurate, 2,5-dimethyl-2,5-di (3-methylbenzoylperoxy) hexane, t-butylperoxy-2- Ethylhexyl monocarbonate, t-hexyl peroxybenzoate, 2,5-dimethyl-2,5-di (benzoyl peroxy) hexane, t-butyl peroxybenzoate, dibutyl peroxytrimethyl adipate, t-amyl peroxynormal octoate , T-Amilperoxyi It may be at least one compound selected from the group consisting of sononanoate and t-amylperoxybenzoate.

The component (d) may contain a radical polymerization initiator having a urethane bond. In other words, the component (d) may contain the component (e).

The amount of chlorine ions or organic acids contained in the radical polymerization initiator is preferably 5000 ppm or less from the viewpoint of suppressing corrosion of electrodes (for example, connection terminals (circuit electrodes) of circuit members). Further, from the same viewpoint, the radical polymerization initiator is more preferably a compound having a small amount of organic acid generated after decomposition. Further, from the viewpoint of further improving the storage stability of the adhesive composition, a radical polymerization initiator having a mass retention rate of 20% by mass or more after being left open for 24 hours at room temperature under normal pressure is preferably used.

The content of the component (d) is preferably 1 part by mass or more, preferably 2.5 parts by mass, based on 100 parts by mass of the total amount of the components (a) and (c) from the viewpoint of obtaining good reactivity in a short time. 3 parts or more is more preferable, 3 parts by mass or more is further preferable, and 4 parts by mass or more is particularly preferable. The content of the component (d) is preferably 15 parts by mass or less, more preferably 10 parts by mass or less, based on 100 parts by mass of the total amount of the components (a) and (c) from the viewpoint of further excellent storage stability. 5, 5 parts by mass or less is more preferable. From these viewpoints, the content of the component (d) is preferably 1 to 15 parts by mass, more preferably 2.5 to 10 parts by mass with respect to 100 parts by mass of the total amount of the components (a) and (c). 3 to 10 parts by mass is more preferable, and 4 to 5 parts by mass is particularly preferable.

[(E) component]
The adhesive composition according to the present embodiment may contain the component (e) as the component (a), the component (c) or the component (d), and the component (a), the component (b), ( The component (e) may be contained as a component other than the component c) and the component (d). Examples of the component other than the component (a), the component (b), the component (c) and the component (d) include urethane beads.

The component (e) is preferably at least one component selected from the group consisting of polyurethane, polyester urethane and urethane (meth) acrylate from the viewpoint of further suppressing peeling after high temperature and high humidity treatment.

As the component (e), one type can be used alone or two or more types can be used in combination. For example, the adhesive composition according to the present embodiment may contain two or more types of the component (a) having a urethane bond, and the component (a) having a urethane bond and the component (c) having a urethane bond. May include. The adhesive composition according to the present embodiment may contain a component (a) having a urethane bond and a component (c) having a urethane bond from the viewpoint of further suppressing peeling after the high temperature and high humidity treatment. preferable.

The content of the component (e) is preferably in the following range based on the total mass of the solid content in the adhesive composition from the viewpoint of further suppressing peeling after the high temperature and high humidity treatment. The content of the component (e) is preferably 5% by mass or more, more preferably 10% by mass or more, and further preferably 15% by mass or more. The content of the component (e) is preferably 95% by mass or less, more preferably 90% by mass or less, and further preferably 85% by mass or less. From these viewpoints, the content of the component (e) is preferably 5 to 95% by mass, more preferably 10 to 90% by mass, still more preferably 15 to 85% by mass.

The content of the component (e) is preferably in the following range with respect to 100 parts by mass of the component (b) from the viewpoint of further suppressing peeling after the high temperature and high humidity treatment. The content of the component (e) is preferably 10 parts by mass or more, more preferably 100 parts by mass or more, further preferably 200 parts by mass or more, and particularly preferably 300 parts by mass or more. The content of the component (e) is preferably 2000 parts by mass or less, more preferably 1000 parts by mass or less, further preferably 750 parts by mass or less, and particularly preferably 500 parts by mass or less. From these viewpoints, the content of the component (e) is preferably 10 to 2000 parts by mass, more preferably 100 to 1000 parts by mass, further preferably 200 to 750 parts by mass, and particularly preferably 300 to 500 parts by mass.

According to the adhesive composition according to the present embodiment, it is presumed that the effect of improving the interfacial adhesion by the silane compound is significantly improved, and an excellent interfacial adhesion can be obtained as compared with the conventional adhesive composition. NS. Although the cause for obtaining such an effect is not clear, the component (b) having a urethane bond is compatible with the component (e), and the component (b) is localized in the adhesive composition or a cured product thereof. It is considered that the difficulty causes the phenomenon that the component (b) bleeds to the surface of the adhesive composition or the cured product thereof is suppressed, and the deactivation of the component (b) is suppressed.

[Other ingredients]
(Silane compounds other than the component (b))
The adhesive composition according to the present embodiment may contain any silane compound different from the component (b). Examples of such silane compounds include vinyltrimethoxysilane, vinyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, and 3- (meth) acryloxipropylmethyl. Dimethoxysilane, 3- (meth) acryloxipropyltrimethoxysilane, 3- (meth) acryloxipropylmethyldiethoxysilane, 3- (meth) acryloxipropyltriethoxysilane, N- (2-aminoethyl) -3 -Aminopropylmethyldimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-isocyanoxidetriethoxysilane, and condensates thereof Can be mentioned.

The content of such a silane compound is preferably 0.1 to 30% by mass, more preferably 0.25 to 20% by mass, based on the total mass of the solid content in the adhesive composition. When the content of the silane compound is in the above range, peeling after the high temperature and high humidity treatment is further suppressed (for example, the generation of peeling bubbles at the interface between the circuit member and the circuit connecting material is further suppressed).

The content of the silane compound in the adhesive composition according to the present embodiment (the total amount of the silane compound containing the component (b)) is determined in the adhesive composition from the viewpoint of further suppressing peeling after the high temperature and high humidity treatment. It may be 0.1% by mass or more, 1% by mass or more, or 5% by mass or more based on the total mass of the solid content of. As the content of the silane compound increases, the average coefficient of linear thermal expansion of the cured product tends to decrease. The content of the silane compound in the adhesive composition according to the present embodiment may be 30% by mass or less, 20% by mass or less, or 15% by mass or less from the viewpoint of excellent film forming property. It may be.

(Insulating filler)
The adhesive composition according to the present embodiment may contain at least one selected from the group consisting of an inorganic filler and an organic filler as the insulating filler. Examples of the inorganic filler include metal oxide fine particles such as silica fine particles, alumina fine particles, silica-alumina fine particles, titania fine particles, and zirconia fine particles; and inorganic fine particles such as nitride fine particles. Examples of the organic filler include organic fine particles such as silicone fine particles, methacrylate-butadiene-styrene fine particles, acrylic-silicone fine particles, polyamide fine particles, and polyimide fine particles. These fine particles may have a uniform structure or may have a core-shell type structure. The adhesive composition according to the present embodiment preferably contains an inorganic filler from the viewpoint of further suppressing peeling after the high temperature and high humidity treatment. When the organic filler is composed of the component (a), the organic filler is classified into the component (a).

The content of each of the organic filler and the inorganic filler is preferably in the following range with respect to 100 parts by mass of the total amount of the component (a) and the component (c) from the viewpoint of further suppressing peeling after the high temperature and high humidity treatment. The content is preferably 1 part by mass or more, and more preferably 5 parts by mass or more. From the viewpoint of reducing the coefficient of linear thermal expansion, the higher the content of the inorganic filler, the more preferable. The content may be 50 parts by mass or less.

The primary particle size of the inorganic filler is preferably 100 nm or less, more preferably 75 nm or less, still more preferably 50 nm or less, from the viewpoint of further suppressing peeling after the high temperature and high humidity treatment. The smaller the primary particle size of the inorganic filler, the larger the total area of the interface between the inorganic filler and the resin (for example, the component (a)) when the same amount is used, and the linear thermal expansion coefficient tends to decrease. The primary particle size of the inorganic filler may be 5 nm or more. The primary particle size of the inorganic filler can be measured with a scanning electron microscope.

(Conductive particles)
The adhesive composition according to this embodiment may contain conductive particles. Adhesive compositions containing conductive particles can be particularly preferably used as anisotropic conductive adhesives.

Examples of the conductive particles include metal particles such as Au, Ag, Pd, Ni, Cu, and solder; carbon particles, and the like. The metal particles may be metal particles in which a plurality of metals are combined. For example, the metal particles may be particles having copper particles and a silver layer coating the copper particles. Further, the conductive particles are composite particles having nuclear particles made of a non-conductive material such as glass, ceramic, and plastic, and conductive layers such as metal, metal particles, and carbon that coat the nuclear particles. May be good. The nucleolus particles of the composite particles are preferably plastic particles.

The composite particles having the plastic particles as core particles have a deformability that is deformed by heating and pressurization. Therefore, when the composite particles are used, the contact area between the circuit electrodes of the circuit members and the conductive particles can be increased, for example, when the circuit members are bonded to each other, as compared with the case where other conductive particles are used. .. Therefore, according to the adhesive composition containing the composite particles as conductive particles, a circuit connection structure that is even more excellent in terms of connection reliability can be obtained.

The adhesive composition according to the present embodiment may contain insulating coated conductive particles having the conductive particles and an insulating layer or insulating particles that cover at least a part of the surface thereof. That is, at least a part of the surface of the conductive particles may be covered with an insulating layer or insulating particles. The insulating layer can be provided by a method such as hybridization. The insulating layer or insulating particles are formed from an insulating material such as a polymer resin. The insulating particles may be the above-mentioned organic filler or inorganic filler. By using such insulating coated conductive particles, short circuits between adjacent conductive particles are less likely to occur.

The average particle size of the conductive particles is preferably 1 to 30 μm from the viewpoint of obtaining good dispersibility and conductivity. The average particle size of the conductive particles can be measured by a laser diffraction type particle size distribution meter.

The content of the conductive particles is preferably 0.1 to 30% by volume, more preferably 0.1 to 10% by volume, and 0.5 to 7.5, based on the total volume of solids in the adhesive composition. Volume% is more preferred. When the content of the conductive particles is 0.1% by volume or more, the conductivity tends to be improved. When the content of the conductive particles is 30% by volume or less, short circuits between electrodes (circuit electrodes, etc.) tend to be less likely to occur. The content (% by volume) of the conductive particles is determined based on the volume of each component constituting the adhesive composition before curing at 23 ° C. The volume of each component can be obtained by converting the mass into a volume using the specific gravity. The volume of each component can also be measured using an appropriate solvent (water, alcohol, etc.) that does not dissolve or swell the component whose volume is to be measured and that can wet the component well. .. Specifically, the solvent can be put into a measuring cylinder or the like, a component to be measured is introduced therein, and the increased volume can be obtained as the volume of the component.

The adhesive composition according to this embodiment may contain a thiol compound. The adhesive composition according to the present embodiment includes an adhesion improver (excluding the component (b) and the silane compound other than the component (b)), a thickener, a leveling agent, a colorant, a weather resistance improver, and the like. Additives may be appropriately contained.

The adhesive composition according to this embodiment may contain a solvent. The solvent is not particularly limited as long as it is a solvent that is not reactive with the components in the adhesive composition and exhibits sufficient solubility. The solvent is preferably a solvent having a boiling point of 50 to 150 ° C. at normal pressure. When the boiling point is 50 ° C. or higher, the solvent is poorly volatile at room temperature, so that it can be used even in an open system. When the boiling point is 150 ° C. or lower, it is easy to volatilize the solvent, so that good reliability can be obtained after bonding.

The average linear thermal expansion coefficient of the cured product of the adhesive composition according to the present embodiment at 30 to 90 ° C. is 800 ppm / K or less. When the average coefficient of linear thermal expansion is larger than 800 ppm / K, it is difficult to obtain the effect of suppressing peeling after the high temperature and high humidity treatment. The average coefficient of linear thermal expansion is preferably 750 ppm / K or less, more preferably 700 ppm / K or less, from the viewpoint of further suppressing peeling after high-temperature and high-humidity treatment. The lower limit of the average coefficient of linear thermal expansion may be, for example, 10 ppm / K or more. The average coefficient of linear thermal expansion of the cured product can be measured using, for example, a thermomechanical analyzer (manufactured by Shimadzu Corporation). Specifically, it can be measured by the method described in Examples.

As a method for lowering the average linear thermal expansion coefficient, for example, (1) a thermoplastic resin having a Tg higher than that of (1) is used, (2) the content of the low molecular weight reactive component is reduced, and the low molecular weight reactive component is used. On the other hand, methods such as using a relatively large amount of the oligomer-sized reactive component in terms of the mass ratio of the solid content, (3) using an inorganic filler, and (4) increasing the content of the silane compound can be mentioned. Examples of the low molecular weight reactive component include isocyanuric acid EO-modified di (meth) acrylate. Examples of the oligomer-sized reactive component include urethane (meth) acrylate.

By the way, the coefficient of linear thermal expansion of glass and polyimide, which are the main materials of the liquid crystal panel and FPC (flexible circuit board), is generally around 10 ppm / K, whereas the wire of the conventional radical polymerization system circuit connection material is used. The coefficient of thermal expansion is 1000 ppm / K or more. Therefore, when the liquid crystal panel and the FPC are connected by a conventional radical polymerization system circuit connection material to produce a structure (that is, in the case of FOG (Flex on Glass) connection), the structure is heated to a high temperature of 85 ° C. and 85% RH. When treated under high humidity conditions, strain occurs at the interface between the FPC and the circuit connection material and the interface between the circuit connection material and the liquid crystal panel due to the difference in the degree of thermal expansion of each member. When the stress due to the strain exceeds the adhesion force at the interface, peeling occurs. Peeling by the same mechanism is not limited to the FOG connection as described above, but also in the case of COG (Chip OnGlass) connection in which the driver IC is mounted on the liquid crystal panel and FOF (Flex on Flex) connection in which the FPC and the FPC are connected. Also tends to occur. On the other hand, in the adhesive composition according to the present embodiment, since the average linear thermal expansion coefficient of the cured product at 30 to 90 ° C. is 800 ppm / K or less, the structure is subjected to high temperature and high humidity conditions of 85 ° C. and 85% RH. Even in the case of treatment, it is presumed that strain at the interface is unlikely to occur, and peeling is unlikely to occur.

The adhesive composition according to the present embodiment can be used in the form of a paste when it is liquid at room temperature. When the adhesive composition is solid at room temperature, it may be used by heating or may be made into a paste by using the above-mentioned solvent.

The adhesive composition according to this embodiment may be in the form of a film. If necessary, a solution of the adhesive composition containing a solvent or the like is applied onto a fluororesin film, a polyethylene terephthalate film, or a peelable base material (release paper, etc.), and then the solvent or the like is removed to form a film. An adhesive composition can be obtained. Further, a film-like adhesive composition can be obtained by impregnating a base material such as a non-woven fabric with the solution, placing the solution on the peelable base material, and then removing the solvent or the like. When the adhesive composition is used in the form of a film, it is more convenient from the viewpoint of excellent handleability and the like. The thickness of the film-like adhesive composition may be 1 to 100 μm or 5 to 50 μm.

The adhesive composition according to the present embodiment can be adhered by pressurizing with heating or light irradiation. By using both heating and light irradiation, adhesion can be performed at a lower temperature in a short time. The light irradiation preferably irradiates light in the wavelength range of 150 to 750 nm. As the light source, a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp (ultra-high pressure mercury lamp, etc.), a xenon lamp, a metal halide lamp, or the like can be used. The irradiation amount may be 0.1 to 10 J / cm ² . The heating temperature is not particularly limited, but is preferably a temperature of 50 to 170 ° C. The pressure is not particularly limited as long as it does not damage the adherend, but is preferably 0.1 to 10 MPa. Heating and pressurization are preferably performed in the range of 0.5 seconds to 3 hours.

The adhesive composition according to the present embodiment may be used as an adhesive for the same type of adherends, or may be used as an adhesive for different types of adherends having different coefficients of thermal expansion. Specifically, it is used as a circuit connection material typified by an anisotropic conductive adhesive, a silver paste, a silver film, etc .; an elastomer for CSP, an underfill material for CSP, a semiconductor element adhesive material typified by LOC tape, etc. be able to.

<Structure and its manufacturing method>
The structure according to the present embodiment includes the adhesive composition according to the present embodiment or a cured product thereof. The structure according to this embodiment is, for example, a semiconductor device such as a circuit connection structure. As one aspect of the structure according to the present embodiment, the circuit connection structure includes a first circuit member having a first circuit electrode, a second circuit member having a second circuit electrode, and a first circuit. It includes a circuit connecting member arranged between the member and the second circuit member. The first circuit member includes, for example, a first substrate and a first circuit electrode arranged on the first substrate. The second circuit member has, for example, a second substrate and a second circuit electrode arranged on the second substrate. The first circuit electrode and the second circuit electrode are opposed to each other and are electrically connected to each other. The circuit connecting member contains the adhesive composition according to the present embodiment or a cured product thereof. The structure according to the present embodiment may include the adhesive composition according to the present embodiment or a cured product thereof, and instead of the circuit member of the circuit connection structure, a member having no circuit electrode ( A substrate or the like) may be used.

The method for producing a structure according to the present embodiment includes a step of curing the adhesive composition according to the present embodiment. As one aspect of the structure manufacturing method according to the present embodiment, the circuit connection structure manufacturing method includes a first circuit member having a first circuit electrode and a second circuit member having a second circuit electrode. The first circuit electrode and the second circuit electrode are pressed by pressurizing the first circuit member and the second circuit member in the arrangement step of arranging the adhesive composition according to the present embodiment. It is provided with a heating and pressurizing step of electrically connecting and heating and curing the adhesive composition. In the arrangement step, the first circuit electrode and the second circuit electrode can be arranged so as to face each other. In the heating and pressurizing step, the first circuit member and the second circuit member can be pressurized in opposite directions.

Hereinafter, a circuit connection structure and a method for manufacturing the same will be described with reference to the drawings as one aspect of the present embodiment. FIG. 1 is a schematic cross-sectional view showing an embodiment of the structure. The circuit connection structure 100a shown in FIG. 1 includes a circuit member (first circuit member) 20 and a circuit member (second circuit member) 30 facing each other, and is between the circuit member 20 and the circuit member 30. Is arranged with a circuit connecting member 10 for connecting them. The circuit connection member 10 contains a cured product of the adhesive composition according to the present embodiment.

The circuit member 20 includes a substrate (first substrate) 21 and a circuit electrode (first circuit electrode) 22 arranged on the main surface 21a of the substrate 21. In some cases, an insulating layer (not shown) may be arranged on the main surface 21a of the substrate 21.

The circuit member 30 includes a substrate (second substrate) 31 and a circuit electrode (second circuit electrode) 32 arranged on the main surface 31a of the substrate 31. In some cases, an insulating layer (not shown) may be arranged on the main surface 31a of the substrate 31.

The circuit connection member 10 contains an insulating substance (cured product of components other than conductive particles) 10a and conductive particles 10b. The conductive particles 10b are arranged at least between the circuit electrodes 22 and the circuit electrodes 32 that face each other. In the circuit connection structure 100a, the circuit electrode 22 and the circuit electrode 32 are electrically connected via the conductive particles 10b.

The circuit members 20 and 30 have one or a plurality of circuit electrodes (connection terminals). As the circuit members 20 and 30, for example, members having electrodes that require electrical connection can be used. As the circuit member, chip parts such as a semiconductor chip (IC chip), a resistor chip, and a capacitor chip; a printed circuit board, a substrate such as a semiconductor mounting substrate, and the like can be used. Examples of the combination of the circuit members 20 and 30 include a semiconductor chip and a semiconductor mounting substrate. Examples of the material of the substrate include inorganic substances such as semiconductors, glass and ceramics; organic substances such as polyimide, polyethylene terephthalate, polycarbonate, (meth) acrylic resin and cyclic olefin resin; and composites of glass and epoxy. The substrate may be a plastic substrate.

FIG. 2 is a schematic cross-sectional view showing another embodiment of the structure. The circuit connection structure 100b shown in FIG. 2 has the same configuration as the circuit connection structure 100a except that the circuit connection member 10 does not contain the conductive particles 10b. In the circuit connection structure 100b shown in FIG. 2, the circuit electrode 22 and the circuit electrode 32 are in direct contact with each other and are electrically connected to each other without using conductive particles.

The circuit connection structures 100a and 100b can be manufactured by, for example, the following methods. First, when the adhesive composition is in the form of a paste, the resin layer containing the adhesive composition is arranged on the circuit member 20 by applying and drying the adhesive composition. When the adhesive composition is in the form of a film, the resin layer containing the adhesive composition is arranged on the circuit member 20 by attaching the film-like adhesive composition to the circuit member 20. Subsequently, the circuit member 30 is placed on the resin layer arranged on the circuit member 20 so that the circuit electrode 22 and the circuit electrode 32 are arranged so as to face each other. Then, by heat-treating or irradiating the resin layer containing the adhesive composition with light, the adhesive composition is cured to obtain a cured product (circuit connection member 10). From the above, the circuit connection structures 100a and 100b can be obtained.

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

<Synthesis of Silane Compound 1>
3-Isocyanatopropyltriethoxysilane (trade name: KBE9007, manufactured by Shin-Etsu Chemical Industry Co., Ltd.) 25 g, 2-hydroxyethyl acrylate (manufactured by Tokyo Chemical Industry Co., Ltd.) 17 g, and dibutyltin dilaurylate (Wako Pure Chemical Industries, Ltd.) (Manufactured by) 60 mg (0.1 mol%) was added to 50 g of methyl ethyl ketone (trade name: 2-butanone, manufactured by Wako Pure Chemical Industries, Ltd., purity 99%) to prepare a reaction solution. The reaction solution was heated to reflux for 120 minutes to obtain silane compound 1 represented by the following formula. The termination of the reaction was confirmed by confirming the disappearance ^{of the absorption peak (2270 cm -1} ) derived from the isocyanate group (NCO group) by FT-IR (Fourier transform infrared spectrophotometer). An infrared spectrophotometer (manufactured by JASCO Corporation) was used for the measurement of FT-IR. Further, the temperature control at the time of heating and reflux was performed by an oil bath (device name: HOB-50D, manufactured by AS ONE Corporation).

<Synthesis of polyurethane>
In a separable flask equipped with a reflux condenser, a thermometer and a stirrer, 1000 parts by mass of polypropylene glycol (manufactured by Wako Pure Chemical Industries, Ltd., number average molecular weight Mn = 2000), which is a diol having an ether bond, and methyl ethyl ketone (manufactured by Wako Pure Chemical Industries, Ltd.) After adding 4000 parts by mass of solvent), the reaction solution was prepared by stirring at 40 ° C. for 30 minutes. After raising the temperature of the reaction solution to 70 ° C., 0.0127 parts by mass of dimethyltin laurate (catalyst) was added. Then, a solution prepared by dissolving 125 parts by mass of 4,4'-diphenylmethane diisocyanate in 125 parts by mass of methyl ethyl ketone was added dropwise to this reaction solution over 1 hour. Then, stirring was continued at the above temperature until no ^{absorption peak (2270 cm -1} ) derived from the isocyanate group was observed by an infrared spectrophotometer (manufactured by Nippon Spectroscopy Co., Ltd.) to obtain a polyurethane methyl ethyl ketone solution. Next, the amount of solvent was adjusted so that the solid content concentration (concentration of polyurethane) of this solution was 30% by mass. The weight average molecular weight of the obtained polyurethane was 320,000 (standard polystyrene conversion value) as a result of measurement by GPC (gel permeation chromatography). Table 1 shows the measurement conditions of GPC.

<Synthesis of urethane acrylate>
In a 2 L (liter) four-necked flask equipped with a thermometer, a stirrer, an inert gas inlet and a reflux condenser, 4000 parts by mass of polycarbonate diol (manufactured by Aldrich, number average molecular weight Mn = 2000) and 2-hydroxy A reaction solution was prepared by charging 238 parts by mass of ethyl acrylate, 0.49 parts by mass of hydroquinone monomethyl ether, and 4.9 parts by mass of a tin catalyst. 666 parts by mass of isophorone diisocyanate (IPDI) was uniformly added dropwise over 3 hours to the reaction solution heated to 70 ° C. to react. After the completion of the dropping, the reaction was continued for 15 hours, and the time when the NCO% (NCO content) became 0.2% by mass or less was regarded as the end of the reaction, and urethane acrylate was obtained. NCO% was confirmed by a potential difference automatic titrator (trade name: AT-510, manufactured by Kyoto Denshi Kogyo Co., Ltd.). As a result of analysis by GPC, the weight average molecular weight of urethane acrylate was 8500 (standard polystyrene conversion value). The analysis by GPC was performed under the same conditions as the analysis of the weight average molecular weight of the polyurethane.

(Preparation of conductive particles)
A nickel layer having a thickness of 0.2 μm was formed on the surface of the polystyrene particles. Further, a gold layer having a thickness of 0.04 μm was formed on the outside of the nickel layer. As a result, conductive particles having an average particle size of 4 μm were produced.

<Making a film-like adhesive>
(Examples 1 to 6 and Comparative Examples 1 to 6)
The components shown in Table 2 were mixed in the mass ratio shown in Table 2. A coating liquid (adhesive composition) for producing a film-like adhesive by dispersing the conductive particles therein at a ratio of 1.5% by volume (reference: total volume of solids in the adhesive composition). ) Was obtained. This coating liquid was applied to a polyethylene terephthalate (PET) film having a thickness of 50 μm using a coating device. The coating film was dried with hot air at 70 ° C. for 10 minutes to prepare a film-like adhesive (film-like adhesive composition) having a thickness of 18 μm. The content of each component of the film-like adhesive shown in Table 2 is the content of solid content.

"Polyurethane", "silane compound 1" and "urethane acrylate" shown in Table 2 are components synthesized as described above. "PKHC" is a phenoxy resin (trade name: PKHC, manufactured by Union Carbide, weight average molecular weight 45,000). PKHC was used in the form of a 40% by mass solution prepared by dissolving 40 g of PKHC in 60 g of methyl ethyl ketone. "KBM503" is 3-methacryloxypropyltrimethoxysilane (trade name: KBM-503, manufactured by Shin-Etsu Chemical Co., Ltd.). "EBECRYL436" is a polyester acrylate (radical polymerizable compound, trade name: EBECRYL436, manufactured by Daicel Ornex Co., Ltd.). "M-215" is isocyanuric acid EO-modified diacrylate (radical polymerizable compound, trade name: M-215, manufactured by Toa Synthetic Co., Ltd.). "P-2M" is 2-methacryloyloxyethyl acid phosphate (phosphate ester, trade name: light ester P-2M, manufactured by Kyoeisha Chemical Co., Ltd.). "Parloyl L" is dilauroyl peroxide (trade name: Parloyl L, manufactured by NOF CORPORATION, molecular weight 398.6, 1-minute half-life temperature: 116 ° C.). "R104" is silica particles (inorganic fine particles, trade name: R104, manufactured by Nippon Aerodil Co., Ltd., primary particle size 12 nm). R104 was used in the form of a 10% by mass dispersion prepared by dispersing 10 g of R104 in a mixed solvent of 45 g of toluene and 45 g of ethyl acetate.

<Measurement of average coefficient of linear thermal expansion>
A plurality of the film-like adhesives were prepared. These film-like adhesives were bonded together using a laminator to a thickness of 100 ± 20 μm, and then treated in an oven at 180 ° C. for 1 hour to prepare a cured product sample. The average coefficient of linear thermal expansion of the prepared sample at 30 to 90 ° C. was measured by a thermomechanical analyzer (manufactured by Shimadzu Corporation). The measurement was carried out on a sample having a length of 10 mm and a width of 4 mm under ^{the conditions of a load of 5 gf (per cross-sectional area of 0.4 mm 2} ) and a heating rate of 5 ° C./min. The results are shown in Table 2.

<Making a connector>
Using the film-like adhesive, a flexible circuit board (FPC) having about 2200 copper circuits having a line width of 75 μm, a pitch of 150 μm (space 75 μm), and a thickness of 18 μm, and a glass (SiO ₂ ) substrate (trade name: pre). It was connected (adhered) to the clean slide S7224 (manufactured by Matsunami Glass Ind. Co., Ltd.). The connection (adhesion) was performed by heating and pressurizing at 140 ° C. and 3 MPa for 5 seconds using a thermocompression bonding device (heating method: constant heat type, manufactured by Toray Engineering Co., Ltd.). As a result, a connector was produced in which the FPC and the glass substrate were connected by a cured product of a film-like adhesive over a width of 1.5 mm. The pressure of pressurization was calculated assuming that the crimping area was 0.495 cm ^2.

<Evaluation of peeling at the glass interface>
Using an optical microscope, the connection appearance immediately after the production of the connection body and the connection appearance after the connection body was left in a constant temperature and humidity chamber at 85 ° C. and 85% RH for 250 hours (after a high temperature and high humidity test) were used. I observed it. The area where peeling occurred at the interface between the glass substrate and the cured product in the space portion (peeling area) was measured, and the presence or absence of peeling at the glass interface was evaluated. When the ratio of the peeled area to the entire space exceeded 30%, it was evaluated as having peeled, and when the ratio of the peeled area was 30% or less, it was evaluated as not peeled. The results are shown in Table 3.

From the above, it was confirmed that in Examples 1 to 6, as compared with Comparative Examples 1 to 6, there was no peeling at the interface between the glass substrate and the cured product even after the high temperature and high humidity treatment, and a good appearance could be maintained. Was done.

10 ... Circuit connection member, 10a ... Insulating material, 10b ... Conductive particles, 20 ... First circuit member, 21 ... First substrate, 21a ... Main surface, 22 ... First circuit electrode, 30 ... Second Circuit member, 31 ... second substrate, 31a ... main surface, 32 ... second circuit electrode, 100a, 100b ... circuit connection structure.

Claims (7)

An adhesive composition containing (a) a thermoplastic resin, (b) a silane compound having a urethane bond and an alkoxysilyl group in the molecule, (c) a radically polymerizable compound, and (d) a radical polymerization initiator. There,
Before SL (c) forming minute to contain a compound having a (e) a urethane bond,
The mass ratio C _b1 / C _{b2 of the content C b1} of the component (c) having a urethane bond to the content C _b2 of the component (c) having no urethane bond is 1 or more.
An adhesive composition having an average linear thermal expansion coefficient of 800 ppm / K or less at 30 to 90 ° C. of a cured product of the adhesive composition. The adhesive composition according to claim 1, wherein the component (b) further comprises at least one selected from the group consisting of a (meth) acryloyl group and a vinyl group. The adhesive composition according to claim 1 or 2, wherein the component (e) contains at least one selected from the group consisting of polyurethane, polyester urethane and urethane (meth) acrylate. The adhesive composition according to any one of claims 1 to 3, wherein the content of the component (c) is 20% by mass or more based on the total mass of the solid content in the adhesive composition. The adhesive composition according to any one of claims 1 to 4, further containing an inorganic filler having a primary particle size of 100 nm or less. A structure comprising the adhesive composition according to any one of claims 1 to 5 or a cured product thereof. A first circuit member having a first circuit electrode and
A second circuit member having a second circuit electrode and
A circuit connecting member arranged between the first circuit member and the second circuit member is provided.
The first circuit electrode and the second circuit electrode are electrically connected to each other.
A structure in which the circuit connecting member contains the adhesive composition according to any one of claims 1 to 5 or a cured product thereof.

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