WO2018181589A1

WO2018181589A1 - Adhesive composition and structure

Info

Publication number: WO2018181589A1
Application number: PCT/JP2018/012994
Authority: WO
Inventors: 直工藤; 泰典川端; 翔太三島; 智樹森尻
Original assignee: 日立化成株式会社
Priority date: 2017-03-29
Filing date: 2018-03-28
Publication date: 2018-10-04
Also published as: TWI781158B; KR102577181B1; TW201840796A; JP7172991B2; JPWO2018181589A1; KR20190133021A; CN110461984A

Abstract

An adhesive composition which contains (a) a thermoplastic resin having a urethane bond, (b) a radically polymerizable compound, (c) a radical polymerization initiator, (d) polyurethane beads and (e) non-conductive inorganic fine particles.

Description

Adhesive composition and structure

The present disclosure relates to an adhesive composition and a structure.

2. Description of the Related Art Various adhesives are conventionally used in semiconductor elements and liquid crystal display elements (display display elements) for the purpose of bonding various members in the elements. The properties required for adhesives are diverse, including adhesiveness, heat resistance, reliability in high temperature and high humidity conditions, and the like. Moreover, as an adherend used for adhesion, a printed wiring board, an organic substrate (polyimide substrate, etc.), metal (titanium, copper, aluminum, etc.), ITO (Indium Tin Oxide), IZO (Indium Zinc Oxide) Base materials having surface states such as IGZO (Indium Gallium Zinc Oxide), SiN _x , and SiO ₂ are used, and molecular design of an adhesive suitable for each adherend is necessary.

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

In recent years, with the high integration of semiconductor elements and the high definition of liquid crystal display elements, the pitch between elements and wirings is narrowed, and there is a possibility of adversely affecting peripheral members due to heat during curing. 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 in a short time (within 1 hour, preferably within 10 seconds, more preferably within 5 seconds) In other words, adhesion by low temperature short time curing (low temperature rapid curing) is required. In order to achieve this low-temperature and 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 normal temperature. .

For this reason, in recent years, attention has been focused on radical curing adhesives using a (meth) acrylate derivative and a peroxide as a radical polymerization initiator in combination. In radical curing systems, radicals that are reactive species are very reactive, so they can be cured for a short time, and the peroxide is stable below the decomposition temperature of the radical polymerization initiator. A curing system that achieves both low-temperature short-time curing and storage stability (for example, storage stability near room temperature). For example, radical curing adhesive compositions as shown in Patent Documents 1 to 3 below are known.

JP 2006-22231 A JP 2009-1765 A International Publication No. 2009/063827

In recent years, the connection portions of semiconductor elements and liquid crystal display elements have been further reduced, and there is a demand for an adhesive having a sufficient adhesive strength even with a smaller connection area. However, it has been found that sufficient adhesive strength cannot be obtained with conventional adhesives.

Therefore, the present disclosure relates to an adhesive composition capable of obtaining sufficient adhesive strength even when the connection area is small in a radical curable adhesive capable of low-temperature and short-time connection (low-temperature and short-time curing), and uses the same. An object of the present invention is to provide a structure.

The inventors of the present invention paid attention to polyurethane beads during the study. Then, the inventors have found that the adhesive strength is particularly high when a resin containing a urethane bond is used as a thermoplastic resin, in the course of studying an adhesive composition containing polyurethane beads. It was. Moreover, it discovered that adhesive strength became higher by using a nonelectroconductive inorganic fine particle in combination with a polyurethane bead.

That is, one aspect of the present disclosure includes (a) a thermoplastic resin having a urethane bond, (b) a radical polymerizable compound, (c) a radical polymerization initiator, (d) a polyurethane bead, An adhesive composition containing conductive inorganic fine particles is provided.

According to the adhesive composition of the present disclosure, high adhesive force can be obtained even when the connection area is small. In the adhesive composition of the present disclosure, in particular, by using a combination of (a) a thermoplastic resin having a urethane bond, (d) polyurethane beads, and (e) non-conductive inorganic fine particles, the connection area is small. The present inventors infer the reason why a high adhesive force can be obtained in some cases as follows. That is, the adhesiveness with the adherend is improved by the flexibility and polarity of the polyurethane beads, and the connection area is small because the adhesive composition and its cured product have sufficient strength by the non-conductive inorganic fine particles. In some cases, it is considered that high adhesive strength can be obtained. In addition, (a) a thermoplastic resin having a urethane bond has a high affinity with (d) polyurethane beads. Therefore, by using these in combination, the dispersibility of (d) polyurethane beads in the adhesive composition can be increased. It is believed that the adhesive strength is greatly improved and excellent adhesive strength can be obtained even when the connection area is small.

The content of the thermoplastic resin having the urethane bond (a) in the adhesive composition of the present disclosure may be equal to or more than the content of the polyurethane beads (d) on a mass basis.

The adhesive composition of the present disclosure may further contain (f) conductive particles.

The adhesive composition of the present disclosure may be for circuit connection (adhesive composition for circuit connection).

Another aspect of the present disclosure provides a structure including the adhesive composition according to one aspect of the present disclosure or a cured product thereof.

Another aspect of the present disclosure 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 connection member disposed between the first circuit electrode and the second circuit electrode, wherein the circuit connection member is an adhesive according to one aspect of the present disclosure. A structure comprising the composition or a cured product thereof is provided.

According to the present disclosure, in a radical curable adhesive capable of low-temperature short-time connection (low-temperature short-time curing), an adhesive composition capable of obtaining high adhesive force even when the connection area is small, and The used structure can be provided.

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

It is a schematic cross section showing one embodiment of a structure of this indication. It is a schematic cross section which shows other one Embodiment of the structure of this indication.

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

In the present specification, “(meth) acrylate” means at least one of acrylate and methacrylate corresponding thereto. The same applies to other similar expressions such as “(meth) acryloyl” and “(meth) acrylic acid”. The materials exemplified below may be used alone or in combination of two or more unless otherwise specified. The content of each component in the composition means the total amount of the plurality of substances present in the composition unless there is a specific notice when there are a plurality of substances corresponding to each component in the composition. The numerical range indicated by using “to” indicates a range including the numerical values described before and after “to” as the minimum value and the maximum value, respectively. “A or B” only needs to include either A or B, and may include both. “Normal temperature” means 25 ° C.

In the numerical ranges described step by step in this specification, the upper limit value or lower limit value of a numerical range of a certain step may be replaced with the upper limit value or lower limit value of the numerical range of another step. Further, in the numerical ranges described in this specification, the upper limit value or the lower limit value of the numerical range may be replaced with the values shown in the examples.

<Adhesive composition>
The adhesive composition of the present embodiment includes (a) a thermoplastic resin having a urethane bond (hereinafter also referred to as (a) component), (b) a radical polymerizable compound (hereinafter also referred to as (b) component), ( c) radical polymerization initiator (hereinafter also referred to as (c) component), (d) polyurethane beads (hereinafter also referred to as (d) component), and (e) non-conductive inorganic fine particles (hereinafter referred to as (e) component) It is also referred to as an adhesive composition. The adhesive composition of this embodiment may further contain (f) conductive particles (hereinafter also referred to as component (f)). The adhesive composition of this embodiment can be suitably used as an adhesive composition for circuit connection. Hereinafter, each component will be described.

(Thermoplastic resin)
The thermoplastic resin (a) having a urethane bond (hereinafter referred to as polyurethane resin) used in the present embodiment can be obtained, for example, by a reaction between a polyol and an isocyanate component such as diisocyanate. The weight average molecular weight of the polyurethane resin is preferably 5,000 to 150,000, and more preferably 10,000 to 80,000. If this value is 5,000 or more, the film forming property tends to be good when the adhesive composition is used in a film form, and if it is 150,000 or less, the compatibility with other components is good. Tend to be.

Examples of the polyol used for the synthesis of the polyurethane resin include polyester polyol, polyether polyol, polycarbonate polyol, acrylic polyol, polyurethane polyol, and aromatic polyol (phthalic acid polyol). Specific examples include those having a basic skeleton of ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, triethylene glycol and the like. These can be used alone or in combination.

Examples of the isocyanate component include diisocyanate compounds such as aromatic diisocyanate, aliphatic diisocyanate, and alicyclic diisocyanate. Specifically, 4,4′-diphenylmethane diisocyanate (MDI), tolylene diisocyanate (TDI), trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), 3-isocyanate methyl-3,5,5-trimethyl Examples thereof include cyclohexyl isocyanate (IPDI). Moreover, the isocyanurate compound (trifunctional) or uretdione compound (bifunctional) formed from the said diisocyanate monomer can also be used as an isocyanate component. Furthermore, terminal isocyanate group polyisocyanate (for example, adduct type polyisocyanate, biuret type polyisocyanate, etc.) can also be used as an isocyanate component. These can be used alone or in combination.

The content of polyurethane resin in the adhesive composition is preferably not less than the content of (d) polyurethane beads on a mass basis. When the content of the polyurethane resin is equal to or greater than the content of the polyurethane bead, the dispersibility of the polyurethane bead in the adhesive composition is further increased by the presence of a relatively large amount of the polyurethane resin having a high affinity with the polyurethane bead. There is a tendency to improve. In addition, the content of the polyurethane resin is 5 to 90 mass based on the total mass of the adhesive component of the adhesive composition ((f) solid content other than the conductive particles in the adhesive composition. The same applies hereinafter). %, More preferably 6 to 80% by mass, still more preferably 8 to 70% by mass, and particularly preferably 10 to 60% by mass. If the content of the polyurethane resin is 5% by mass or more, the dispersibility of the polyurethane beads tends to be improved and the adhesive strength tends to be further improved, and if it is 90% by mass or less, the fluidity of the adhesive composition is good. There is a tendency to be able to.

The adhesive composition of the present embodiment can be used in combination with a known thermoplastic resin other than the polyurethane resin. Examples of the thermoplastic resin other than the polyurethane resin include one or more resins selected from polyimide resins, polyamide resins, phenoxy resins, poly (meth) acrylic resins, polyester resins, and polyvinyl butyral resins.

The weight average molecular weight of such a thermoplastic resin is preferably 5000 to 400000, more preferably 5000 to 200000, and still more preferably 10,000 to 150,000. When the weight average molecular weight of such a thermoplastic resin is 5000 or more, there is a tendency that the adhesive strength of the adhesive composition can be improved, and when the weight average molecular weight is 400000 or less, compatibility with other components is high. It is favorable and tends to suppress a decrease in fluidity of the adhesive.

As the thermoplastic resin, a rubber component can also be used for the purpose of stress relaxation and adhesion improvement. 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-terminated styrene-butadiene rubber, carboxylated nitrile rubber, hydroxyl-terminated poly (oxypropylene), alkoxysilyl group-terminated poly (oxypropylene), poly (oxytetramethylene) glycol, polyolefin glycol, and poly-ε-caprolactone. It is done. The rubber component preferably has a cyano group or a carboxyl group, which is a highly polar group, as a side chain group or a terminal group from the viewpoint of improving adhesiveness. These rubber components can be used alone or in combination of two or more.

The total content of the thermoplastic resin in the adhesive composition is preferably 20 to 90% by mass, more preferably 20 to 80% by mass, based on the total mass of the adhesive component of the adhesive composition. The content is preferably 30 to 70% by mass. (A) When the content of the thermoplastic resin is 20% by mass or more, the film forming property of the adhesive composition tends to be improved while improving the adhesive strength. When the content is 90% by mass or less, the adhesive is used. There is a tendency that the fluidity of the composition can be improved.

(Radically polymerizable compound)
(B) The radical polymerizable compound is a compound having a radical polymerizable functional group. Examples of such radically polymerizable compounds include (meth) acrylate compounds, maleimide compounds, citraconic imide resins, and nadiimide resins. “(Meth) acrylate compound” means a compound having a (meth) acryloyl group. A radically polymerizable compound may be used in the state of a monomer or an oligomer, and can also use a monomer and an oligomer together. A radically polymerizable compound may be used individually by 1 type, and may be used in combination of 2 or more type.

Specific examples of the (meth) acrylate compound include methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, isobutyl (meth) acrylate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, Trimethylolpropane tri (meth) acrylate, tetramethylolmethanetetra (meth) acrylate, 2-hydroxy-1,3-di (meth) acryloxypropane, 2,2-bis [4-((meth) acryloxymethoxy) Phenyl] propane, 2,2-bis [4-((meth) acryloxypolyethoxy) phenyl] propane, dicyclopentenyl (meth) acrylate, tricyclodecanyl (meth) acrylate, tris ((meth) acryloyloxy D Le) isocyanurate, urethane (meth) acrylate, isocyanuric acid EO-modified di (meth) acrylate, 9,9-bis [4- (2- (meth) acryloyloxy ethoxy) phenyl] fluorene, and the like. As radically polymerizable compounds other than (meth) acrylate compounds, for example, compounds described in Patent Document 3 (International Publication No. 2009/063827) can be preferably used. A (meth) acrylate compound may be used individually by 1 type, and may be used in combination of 2 or more type.

As the radically polymerizable compound, a (meth) acrylate compound is preferable and urethane (meth) acrylate is more preferable from the viewpoint of obtaining further excellent storage stability. From the viewpoint of improving heat resistance, the (meth) acrylate compound preferably has at least one substituent selected from the group consisting of a dicyclopentenyl group, a tricyclodecanyl group, and a triazine ring.

Further, as the radical polymerizable compound, a radical polymerizable compound having a phosphate ester structure represented by the following general formula (1) is preferably used, and the radical polymerizable compound such as a (meth) acrylate compound and the formula ( It is more preferable to use together with the radically polymerizable compound which has the phosphate ester structure represented by 1). In these cases, since the adhesive strength to the surface of an inorganic substance (metal etc.) improves, it is suitable for adhesion | attachment of circuit electrodes, for example.

[Wherein, p represents an integer of 1 to 3, and R represents a hydrogen atom or a methyl group. ]

The radical polymerizable compound having a phosphoric ester structure can be obtained, for example, by reacting phosphoric anhydride with 2-hydroxyethyl (meth) acrylate. Specific examples of the radical polymerizable compound having a phosphate structure include mono (2- (meth) acryloyloxyethyl) acid phosphate, di (2- (meth) acryloyloxyethyl) acid phosphate, and the like. . The radically polymerizable compound having a phosphate ester structure represented by the formula (1) may be used alone or in combination of two or more.

The content of the radical polymerizable compound having a phosphate ester structure represented by the formula (1) is a radical polymerizable compound (total amount of components corresponding to the radical polymerizable compound. From the viewpoint of obtaining further excellent adhesiveness. 1) to 100% by mass, more preferably 1 to 50% by mass, still more preferably 1 to 10% by mass, based on the total mass of the same). The content of the radically polymerizable compound having the phosphate ester structure represented by the formula (1) is that of the radically polymerizable compound and the film forming material (components used as necessary) from the viewpoint of obtaining further excellent adhesiveness. Based on the total mass, 0.01 to 50 mass% is preferable, 0.5 to 10 mass% is more preferable, and 0.5 to 5 mass% is still more preferable.

The radical polymerizable compound may contain allyl (meth) acrylate. In this case, the content of allyl (meth) acrylate is preferably 0.1 to 10% by mass, based on the total mass of the radical polymerizable compound and the film-forming material (components used as necessary), preferably 0.5 to 5 mass% is more preferable.

The content of the radical polymerizable compound is preferably in the following range based on the total mass of the adhesive component of the adhesive composition from the viewpoint of obtaining further excellent adhesiveness. The content of the radical polymerizable compound is preferably 10% by mass or more, more preferably 20% by mass or more, further preferably 30% by mass or more, and further preferably 40% by mass or more. preferable. The content of the radically polymerizable compound is preferably 90% by mass or less, more preferably 80% by mass or less, further preferably 70% by mass or less, and particularly preferably 60% by mass or less. Preferably, it is very preferably 50% by mass or less. From these viewpoints, the content of the radical polymerizable compound is preferably 10 to 90% by mass, more preferably 20 to 80% by mass, still more preferably 30 to 70% by mass, It is particularly preferably from 60 to 60% by weight, and very preferably from 40 to 50% by weight.

(Radical polymerization initiator)
(C) As the radical polymerization initiator, an initiator that generates free radicals by heat (heating), an initiator that generates free radicals by light, an initiator that generates free radicals by ultrasonic waves, electromagnetic waves, or the like is used. Can do.

An initiator that generates free radicals by heat is a compound that decomposes by heat to generate free radicals. Examples of such compounds include peroxides (such as organic peroxides) and azo compounds. Such radical polymerization initiator is appropriately selected depending on the intended connection temperature, connection time, pot life, and the like. From the viewpoint of stability, reactivity, and compatibility, a peroxide having a one-minute half-life temperature of 90 to 175 ° C. and a molecular weight of 180 to 1000 is preferred. “1 minute half-life temperature” refers to a temperature at which the half-life of the peroxide is 1 minute. “Half-life” refers to the time taken for the concentration of a compound to decrease to half of its initial value at a given temperature. The 1-minute half-life temperature is a value published in a catalog (organic peroxide (10th edition, February 2015)) issued by NOF Corporation.

Specific examples of the initiator that generates free radicals by heat include diacyl peroxide, peroxydicarbonate, peroxyester, peroxyketal, dialkyl peroxide, hydroperoxide, silyl peroxide, and the like.

As the radical polymerization initiator, from the viewpoint of suppressing corrosion of electrodes (circuit electrodes, etc.), an initiator having a concentration of contained chlorine ions and organic acids of 5000 ppm or less is preferable, and an organic acid generated after thermal decomposition is low. An agent is more preferable. Specific examples of such initiators include peroxyesters, dialkyl peroxides, hydroperoxides, silyl peroxides, and the like, and peroxyesters are more preferable from the viewpoint of obtaining high reactivity.

Examples of the radical polymerization initiator include 1,1,3,3-tetramethylbutylperoxyneodecanoate, di (4-tert-butylcyclohexyl) peroxydicarbonate, di (2-ethylhexyl) peroxydi Carbonate, cumylperoxyneodecanoate, 1,1,3,3-tetramethylbutylperoxyneodecanoate, dilauroyl peroxide, 1-cyclohexyl-1-methylethylperoxyneodecanoate, t- Hexyl peroxyneodecanoate, t-butyl peroxyneodecanoate, t-butyl peroxypivalate, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, 2,5 -Dimethyl-2,5-di (2-ethylhexanoylperoxy) hexane, t-hexyl -Oxy-2-ethylhexanoate, t-butylperoxy-2-ethylhexanoate, t-butylperoxyneoheptanoate, t-amylperoxy-2-ethylhexanoate, di-t-butyl Peroxyhexahydroterephthalate, t-amylperoxy-3,5,5-trimethylhexanoate, 3-hydroxy-1,1-dimethylbutylperoxyneodecanoate, 1,1,3,3-tetramethyl Butylperoxy-2-ethylhexanoate, t-amylperoxyneodecanoate, t-amylperoxy-2-ethylhexanoate, 3-methylbenzoyl peroxide, 4-methylbenzoyl peroxide, di ( 3-methylbenzoyl) peroxide, dibenzoyl peroxide, di (4-methyl) Nzoyl) peroxide, 2,2'-azobis-2,4-dimethylvaleronitrile, 1,1'-azobis (1-acetoxy-1-phenylethane), 2,2'-azobisisobutyronitrile, , 2′-azobis (2-methylbutyronitrile), dimethyl-2,2′-azobisisobutyronitrile, 4,4′-azobis (4-cyanovaleric acid), 1,1′-azobis (1- Cyclohexanecarbonitrile), t-hexylperoxyisopropyl monocarbonate, t-butylperoxymaleic acid, t-butylperoxy-3,5,5-trimethylhexanoate, t-butylperoxylaurate, 2,5 -Dimethyl-2,5-di (3-methylbenzoylperoxy) hexane, t-butylperoxy-2-ethylhexyl monocar Bonate, t-hexylperoxybenzoate, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, t-butylperoxybenzoate, dibutylperoxytrimethyladipate, t-amylperoxynormal octoate, t -One or more compounds selected from amyl peroxyisononanoate and t-amyl peroxybenzoate.

An initiator that generates free radicals by light is a compound that decomposes by light to generate free radicals. As such an initiator, a compound that generates free radicals upon irradiation with light having a wavelength of 150 to 750 nm can be used. Examples of such a compound include Photoinitiation, Photopolymerization, and Photocuring, J.A. -P. Α-Acetaminophenone derivatives and phosphine oxide derivatives described in Fouassier, Hanser Publishers (1995), p17 to p35 are preferred.

The radical polymerization initiator may be used alone or in combination of two or more. You may use together an initiator, a decomposition accelerator, a decomposition inhibitor, etc. In addition, the initiator may be coated with a polyurethane-based or polyester-based polymer substance to form microcapsules. Microencapsulated initiators are preferred because the pot life is extended.

The content of the radical polymerization initiator 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 (b). .

(Polyurethane beads)
The polyurethane beads (d) used in the present embodiment are spherical organic fine particles made of a crosslinked urethane resin.

Polyurethane beads can be synthesized by reacting a polyol component and an isocyanate component. As the polyol, bifunctional ones are mainly used, but trifunctional or higher ones may be used in combination. When a trifunctional or higher functional group is used in combination, the degree of crosslinking of the polyurethane beads can be increased.

Examples of the polyol component include polyester polyol, polyether polyol, polycarbonate polyol, acrylic polyol, polyurethane polyol, and aromatic polyol (phthalic acid polyol). Of these, polycarbonate polyols or aromatic polyols are preferred in terms of improving hydrolysis resistance. Moreover, as a polyol, a polyfunctional polyol is preferable at the point which makes the crosslinking degree of a polyurethane bead high and an elastic recovery property becomes high. Examples of the polyfunctional polyol include a trifunctional polycaprolactone-based polyol. The polyfunctional polyol has higher flexibility as the weight average molecular weight is larger. These can be used alone or in combination.

The isocyanate component may be any of yellowing type, non-yellowing type, and hardly yellowing type. Examples of the isocyanate component include diisocyanate compounds such as aromatic diisocyanate, aliphatic diisocyanate, and alicyclic diisocyanate. Specifically, for example, 4,4′-diphenylmethane diisocyanate (MDI), tolylene diisocyanate (TDI), trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), 3-isocyanate methyl-3,5,5 -Trimethylcyclohexyl isocyanate (IPDI) and the like. Moreover, the isocyanurate compound (trifunctional) or uretdione compound (bifunctional) formed from the said diisocyanate monomer can also be used as an isocyanate component. Furthermore, terminal isocyanate group polyisocyanate (for example, adduct type polyisocyanate, biuret type polyisocyanate, etc.) can also be used as an isocyanate component. These can be used alone or in combination.

The average particle diameter of the polyurethane beads is not particularly limited, but is preferably 50 nm to 10 μm, more preferably 70 nm to 6 μm, and further preferably 70 nm to 5 μm. Since it may be technically difficult to produce polyurethane beads of less than 50 nm, it is preferably 50 nm or more from the viewpoint of availability. Moreover, when it is 10 micrometers or less, when it mix | blends with another adhesive composition, it is hard to generate | occur | produce aggregation, and even if aggregation generate | occur | produces, there exists a tendency which can suppress deterioration of filterability. The average particle diameter can be confirmed by SEM, for example.

The content of polyurethane beads is preferably less than the content of the polyurethane resin as component (a). In addition, it is preferably 3 to 50% by mass, more preferably 4 to 40% by mass, and more preferably 5 to 30% by mass based on the total mass of the adhesive component of the adhesive composition. Is more preferable, and 8 to 25% by mass is particularly preferable. When the content is 3% by mass or more, sufficient adhesive strength tends to be easily obtained. When the content is 50% by mass or less, a decrease in fluidity of the adhesive tends to be suppressed.

(Non-conductive inorganic fine particles)
As the non-conductive inorganic fine particles of the component (e), known non-conductive inorganic fine particles can be used without particular limitation. Examples of the nonconductive inorganic fine particles include nonconductive inorganic fine particles such as silica fine particles, alumina fine particles, silica-alumina fine particles, titania fine particles, and zirconia fine particles. These can be used individually by 1 type or in mixture of 2 or more types. In the present embodiment, (e) non-conductive inorganic fine particles have no conductivity, and do not belong to (f) conductive particles described later.

The average particle size of the nonconductive inorganic fine particles is preferably less than 1 μm, and more preferably 0.1 to 0.5 μm. Here, the average particle diameter is the mode diameter in the major axis direction when present in the circuit connecting material. Further, the average primary particle diameter of the component (e) is preferably 100 nm or less, and more preferably 10 to 30 nm. In addition, in this specification, an average particle diameter and an average primary particle diameter show the value measured by image analysis.

As the non-conductive inorganic fine particles, fine particles whose surface is modified with an organic group can be suitably used because of excellent dispersibility. Examples of the organic group include a dimethylsiloxane group and a diphenylsiloxane group.

The content of the non-conductive inorganic fine particles is preferably 1 to 30% by mass, more preferably 2 to 25% by mass based on the total mass of the adhesive component, and 5 to 20% by mass. More preferably. When the content of the component (e) is in the above range, the effects of the present disclosure are more remarkably exhibited.

(Conductive particles)
The adhesive composition of the present embodiment may further contain (f) conductive particles. Examples of the constituent material of the conductive particles include gold (Au), silver (Ag), nickel (Ni), copper (Cu), metals such as solder, carbon, and the like. Also, coated conductive particles in which a non-conductive resin, glass, ceramic, plastic, or the like is used as a core, and the metal (metal particles or the like) or carbon is coated on the core may be used. Since the coated conductive particles or the hot-melt metal particles are deformable by heating and pressing, the variation in the height of the circuit electrode is eliminated at the time of connection, and the contact area with the electrode is increased at the time of connection, thereby improving the reliability. Therefore, it is preferable.

The average particle diameter of the conductive particles is preferably 1 to 30 μm, more preferably 2 to 25 μm, and further preferably 3 to 20 μm from the viewpoint of excellent dispersibility and conductivity. The average particle diameter of the conductive particles can be measured using instrumental analysis such as laser diffraction.

From the viewpoint of excellent conductivity, the content of the conductive particles is preferably 0.1 part by volume or more, and more preferably 1 part by volume or more with respect to 100 parts by volume of the total volume of the adhesive component of the adhesive composition. The content of the conductive particles is preferably 50 parts by volume or less, more preferably 20 parts by volume or less, based on the total volume of the adhesive component of the adhesive composition, from the viewpoint of easily suppressing short-circuiting of electrodes (circuit electrodes, etc.). Preferably, 10 parts by volume or less is more preferable, 5 parts by volume or less is particularly preferable, and 3 parts by volume or less is extremely preferable. From these viewpoints, the content of the conductive particles is preferably 0.1 to 50 parts by volume, more preferably 0.1 to 20 parts by volume, still more preferably 1 to 20 parts by volume, and particularly preferably 1 to 10 parts by volume. 1 to 5 parts by volume is very preferable, and 1 to 3 parts by volume is very preferable. The “volume part” is determined based on the volume of each component before curing at 23 ° C., and the volume of each component can be converted from mass to volume using specific gravity. In addition, the volume of the target component is increased by adding the target component to a container in which a suitable solvent (water, alcohol, etc.) that does not dissolve or swell the target component and wets the target component well is placed in a graduated cylinder. Can also be sought.

(Silane coupling agent)
The adhesive composition according to the present embodiment may contain a silane coupling agent. The silane coupling agent is preferably a compound represented by the following formula (2).

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

Examples of the silane coupling agent of the formula (2) include vinyltrimethoxysilane, vinyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3- (meth) Acryloxypropylmethyldimethoxysilane, 3- (meth) acryloxypropyltrimethoxysilane, 3- (meth) acryloxypropylmethyldiethoxysilane, 3- (meth) acryloxypropyltriethoxysilane, N-2- (amino Ethyl) -3-aminopropylmethyldimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane and 3-isocyanatopropyltriethoxysilane. That.

The content of the silane coupling agent is preferably 0.1 to 10 parts by mass and preferably 0.25 to 5 parts by mass with respect to 100 parts by mass of the total amount of the components (a) and (b). Is more preferable. If the content of the silane coupling agent is 0.1 parts by mass or more, the effect of suppressing the separation of the interface between the circuit member and the circuit connecting material and the generation of bubbles tends to increase. When the content is 10 parts by mass or less, the pot life of the adhesive composition tends to be long.

(Other ingredients)
The adhesive composition of this embodiment may contain a polymerization inhibitor such as hydroquinone and methyl ether hydroquinone as needed.

The adhesive composition of this embodiment is a homopolymer or copolymer obtained by polymerizing at least one monomer component selected from the group consisting of (meth) acrylic acid, (meth) acrylic acid ester and acrylonitrile. Furthermore, you may contain. The adhesive composition of the present embodiment preferably contains acrylic rubber or the like, which is a copolymer obtained by polymerizing glycidyl (meth) acrylate having a glycidyl ether group, from the viewpoint of excellent stress relaxation. The weight average molecular weight of the acrylic rubber is preferably 200,000 or more from the viewpoint of increasing the cohesive strength of the adhesive composition.

The adhesive composition of the present embodiment may contain coated fine particles obtained by coating the surfaces of the conductive particles with a polymer resin or the like. When such coated fine particles are used in combination with the above conductive particles, even if the content of the conductive particles is increased, it is easy to suppress short-circuiting due to contact between the conductive particles, so that insulation between adjacent circuit electrodes can be prevented. Can be improved. The coated fine particles may be used alone without using conductive particles, or the coated fine particles and conductive particles may be used in combination. When the adhesive composition contains coated fine particles, the “adhesive component of the adhesive composition” in the present specification means a solid content other than the conductive particles and the coated fine particles in the adhesive composition.

The adhesive composition of this embodiment can also contain rubber fine particles, fillers, softeners, accelerators, anti-aging agents, colorants, flame retardants, thixotropic agents, and the like. Moreover, the adhesive composition of this embodiment may contain additives, such as a thickener, a leveling agent, and a weather resistance improver, as appropriate.

The rubber fine particles have an average particle size not more than twice the average particle size of the conductive particles, and the storage elastic modulus at normal temperature is 1/2 of the storage elastic modulus at normal temperature of the conductive particles and the adhesive composition. The following particles are preferred. In particular, when the rubber fine particles are made of silicone, acrylic emulsion, SBR (Styrene-Butadiene Rubber), NBR (Nitril-Butadiene Rubber) or polybutadiene rubber, the rubber fine particles may be used alone or in combination of two or more. Is preferred. The three-dimensionally cross-linked rubber fine particles have excellent solvent resistance and are easily dispersed in the adhesive composition.

The filler can improve the electrical characteristics (connection reliability, etc.) between the circuit electrodes. As the filler, for example, particles having an average particle size of 1/2 or less of the average particle size of the conductive particles can be suitably used. When particles having no conductivity are used in combination with a filler, particles having an average particle size not more than the particles having no conductivity can be used as the filler. The content of the filler is preferably 0.1 to 60% by mass based on the total amount of the adhesive component of the adhesive composition. When the content is 60% by mass or less, the effect of improving connection reliability tends to be obtained more sufficiently. When the content is 0.1% by mass or more, the effect of adding the filler tends to be sufficiently obtained.

The adhesive composition of this 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 heated and used, or may be made into a paste using a solvent. The solvent that can be used is not particularly limited as long as it 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, and can be used even in an open system. When the boiling point is 150 ° C. or lower, it is easy to volatilize the solvent, and thus good reliability can be obtained after bonding.

The adhesive composition of the present embodiment may be in the form of a film. If necessary, an adhesive composition containing a solvent or the like is applied onto, for example, a fluororesin film, a polyethylene terephthalate film, or a peelable substrate (release paper, etc.), and then the solvent is removed to remove the film. Can be obtained. Moreover, after impregnating base materials, such as a nonwoven fabric, with the said solution and mounting on a peelable base material, a film-form adhesive composition can be obtained by removing a solvent etc. When the adhesive composition is used in the form of a film, the handleability is excellent.

The adhesive composition of this embodiment can be adhered by applying pressure together with heating or light irradiation. By using heating and light irradiation in combination, it can be bonded at a lower temperature in a shorter time. The light irradiation is preferably performed in the wavelength region of 150 to 750 nm. As the light source, a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp (extra-high-pressure mercury lamp, etc.), a xenon lamp, a metal halide lamp, or the like can be used. The irradiation dose may be 0.1-10 J / cm ² . The heating temperature is not particularly limited, but a temperature of 50 to 170 ° C. is preferable. 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 of the present embodiment may be used as an adhesive for the same type of adherend, or as an adhesive for different types of adherends having different thermal expansion coefficients. Specifically, circuit connection materials typified by anisotropic conductive adhesive, silver paste, silver film, etc .; CSP (Chip Size Package) elastomer, CSP underfill material, LOC (Lead on Chip) tape, etc. It can be used as a semiconductor element adhesive material.

<Structure and manufacturing method thereof>
The structure of this embodiment includes the adhesive composition of this embodiment or a cured product thereof. The structure of this embodiment is a semiconductor device such as a circuit connection structure. As one aspect of the structure of 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 member. And a circuit connecting member disposed between the second circuit members. The first circuit member includes, for example, a first substrate and a first circuit electrode disposed on the first substrate. The second circuit member includes, for example, a second substrate and a second circuit electrode disposed on the second substrate. The first circuit electrode and the second circuit electrode face each other and are electrically connected. The circuit connection member includes the adhesive composition of the present embodiment or a cured product thereof. The structure which concerns on this embodiment should just be equipped with the adhesive composition which concerns on this embodiment, or its hardened | cured material, and it replaces with the circuit member of the said circuit connection structure, and is a member which does not have a circuit electrode ( A substrate or the like) may be used.

The structure manufacturing method of the present embodiment includes a step of curing the adhesive composition of the present embodiment. As one aspect of the structure manufacturing method of 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. Between the step of arranging the adhesive composition of the present embodiment, and pressurizing the first circuit member and the second circuit member to electrically connect the first circuit electrode and the second circuit electrode. And a heating and pressing step of heating and curing the adhesive composition. In the arranging step, the first circuit electrode and the second circuit electrode can be arranged to face each other. In the heating and pressurizing step, the first circuit member and the second circuit member can be pressurized in the opposite directions.

Hereinafter, a circuit connection structure and a manufacturing method thereof will be described as an aspect of the present embodiment with reference to the drawings. FIG. 1 is a schematic cross-sectional view showing an embodiment of a structure. A circuit connection structure 100 a shown in FIG. 1 includes a circuit member (first circuit member) 20 and a circuit member (second circuit member) 30 that are opposed to each other, and between the circuit member 20 and the circuit member 30. The circuit connection member 10 which connects these is arrange | positioned. The circuit connection member 10 includes a cured product of the adhesive composition of the present embodiment.

The circuit member 20 includes a substrate (first substrate) 21 and a circuit electrode (first circuit electrode) 22 disposed on the main surface 21 a of the substrate 21. An insulating layer (not shown) may be disposed on the main surface 21a of the substrate 21 as the case may be.

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

The circuit connecting member 10 contains an insulating substance (cured product of components excluding conductive particles) 10a and conductive particles 10b. The conductive particles 10b are disposed at least between the circuit electrode 22 and the circuit electrode 32 facing 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, a chip component such as a semiconductor chip (IC chip), a resistor chip, or a capacitor chip; a substrate such as a printed board or a semiconductor mounting board 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 semiconductor, glass, and ceramic; 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 and are electrically connected without interposing conductive particles.

The

circuit connection structures

100a and 100b can be manufactured, for example, by the following method. First, when the adhesive composition is in a paste form, the resin layer containing the adhesive composition is disposed 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 disposed on the circuit member 20 by sticking the film-like adhesive composition to the circuit member 20. Subsequently, the circuit member 30 is placed on the resin layer disposed on the circuit member 20 so that the circuit electrode 22 and the circuit electrode 32 are opposed to each other. And a heat treatment or light irradiation is performed to the resin layer containing an adhesive composition, an adhesive composition hardens | cures and hardened | cured material (circuit connection member 10) is obtained. Thus, the

circuit connection structures

100a and 100b are obtained.

Hereinafter, the present disclosure will be described more specifically with reference to examples and comparative examples. However, the present disclosure is not limited to the following examples.

(Synthesis of polyurethane resin)
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 ( Solvent) After adding 4000 parts by mass, the mixture was stirred at 40 ° C. for 30 minutes to prepare a reaction solution. After heating up the said reaction liquid to 70 degreeC, 0.0127 mass part of dimethyltin laurate (catalyst) was added. Next, a solution prepared by dissolving 125 parts by mass of 4,4′-diphenylmethane diisocyanate in 125 parts by mass of methyl ethyl ketone was added dropwise to the reaction solution over 1 hour. Thereafter, stirring was continued at the above temperature until an absorption peak (2270 cm ⁻¹ ) derived from an isocyanate group was not observed with an infrared spectrophotometer (manufactured by JASCO Corporation) to obtain a polyurethane methylethylketone solution. Next, the amount of solvent was adjusted so that the solid content concentration (polyurethane concentration) of this solution was 30% by mass. The weight average molecular weight of the obtained polyurethane (polyurethane resin) was 320,000 (standard polystyrene conversion value) as a result of measurement by GPC (gel permeation chromatography). Table 1 shows the GPC measurement conditions.

(Synthesis of urethane acrylate)
In a 2 L (liter) four-necked flask equipped with a thermometer, stirrer, inert gas inlet and reflux condenser, 4000 parts by mass of polycarbonate diol (manufactured by Aldrich, number average molecular weight 2000) and 2-hydroxyethyl A reaction solution was prepared by charging 238 parts by mass of acrylate, 0.49 parts by mass of hydroquinone monomethyl ether, and 4.9 parts by mass of a tin-based catalyst. To the reaction liquid heated to 70 ° C., 666 parts by mass of isophorone diisocyanate (IPDI) was uniformly dropped over 3 hours to be reacted. After completion of the dropwise addition, the reaction was continued for 15 hours, and the time when NCO% (NCO content) became 0.2% by mass or less was regarded as the completion of the reaction, and urethane acrylate was obtained. NCO% was confirmed by a potentiometric automatic titrator (trade name: AT-510, manufactured by Kyoto Electronics Industry Co., Ltd.). As a result of analysis by GPC, the weight average molecular weight of urethane acrylate was 8500 (standard polystyrene conversion value). In addition, the analysis by GPC was performed on the same conditions as the analysis of the weight average molecular weight of the said polyurethane resin.

(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 outside the nickel layer. Thereby, conductive particles having an average particle diameter of 4 μm were produced.

[Examples 1 to 7 and Comparative Examples 1 to 4]
(Production of film adhesive)
The components shown in Table 2 were mixed at a mass ratio (solid content) shown in Table 2 to obtain a mixture. Coating for forming a film adhesive by dispersing the conductive particles in this mixture at a ratio of 1.5 parts by volume (standard: ratio relative to 100 parts by volume of the total adhesive component of the adhesive composition). A liquid was obtained. This coating solution was applied to a polyethylene terephthalate (PET) film having a thickness of 50 μm using a coating apparatus. The coating film was dried with hot air at 70 ° C. for 10 minutes to form a film adhesive having a thickness of 18 μm.

In addition, the detail of each component shown in Table 2 is as follows.
Polyurethane resin: A polyurethane resin synthesized as described above was used.
Phenoxy resin: Used in the form of a 40% by mass solution prepared by dissolving 40 g of PKHC (manufactured by Union Carbide Corporation, trade name, weight average molecular weight 45000) in 60 g of methyl ethyl ketone.
Radical polymerizable compound A: Urethane acrylate synthesized as described above was used.
Radical polymerizable compound B: Isocyanuric acid EO-modified diacrylate (trade name: M-215, manufactured by Toa Gosei Co., Ltd.) was used.
Radical polymerizable compound C (phosphate ester): 2-methacryloyloxyethyl acid phosphate (trade name: Light Ester P-2M, manufactured by Kyoeisha Chemical Co., Ltd.) was used.
Peroxide (radical polymerization initiator): 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate (trade name: Perocta O, manufactured by NOF Corporation, 1 minute half-life temperature: 124 .3 ° C).
Polyurethane beads A: P-800T (trade name, average particle size: 6 μm, glass transition temperature: −34 ° C.) manufactured by Negami Kogyo Co., Ltd. 10 g was used in the form of a 10% by mass solution dispersed in 90 g of methyl ethyl ketone.
Polyurethane beads B: JB-800T (manufactured by Negami Kogyo Co., Ltd., trade name, average particle size: 6 μm, glass transition temperature: −52 ° C.) 10 g was used in the form of a 10% by mass solution dispersed in 90 g of methyl ethyl ketone.
Silica fine particles (non-conductive inorganic fine particles): 10 g of R104 (trade name, manufactured by Nippon Aerosil Co., Ltd.) dispersed in a mixed solvent of 45 g of toluene and 45 g of ethyl acetate was used.

(Production of connected body)
A flexible circuit board (FPC) having 2200 copper circuits having a line width of 75 μm, a pitch of 150 μm (space of 75 μm) and a thickness of 18 μm using the film adhesives of Examples 1 to 7 and Comparative Examples 1 to 4, and glass The substrate and a SiN _x substrate (thickness 0.7 mm) having a thin layer of 0.2 μm thick silicon nitride (SiN _x ) formed on the glass substrate were connected. The connection was performed by heating and pressurizing at 170 ° C. and 3 MPa for 5 seconds using a thermocompression bonding apparatus (heating method: constant heat type, manufactured by Toray Engineering Co., Ltd.). As a result, a connection body (structure) in which the FPC and the SiN _x substrate were connected by the cured product of the film adhesive over a width of 1.5 mm and a width of 1.0 mm was produced. Pressure of the pressure, the pressure bonding area in the case of width 1.5mm 0.495cm ^2, in the case of width 1.0mm was calculated as 0.330cm ^2.

<Measurement of adhesive strength>
The adhesive strength of the obtained connection body was measured by a 90-degree peeling method according to JIS-Z0237. Tensilon UTM-4 (manufactured by Toyo Baldwin Co., Ltd., trade name, peel strength 50 mm / min, 25 ° C.) was used as an adhesive strength measuring device. The results are shown in Table 2.

From Table 2, it was confirmed that the film-like adhesives of the Examples can obtain higher adhesive strength (8 N / cm or more) even when connected to a width of 1.0 mm than the film-like adhesives of Comparative Examples. With the film-like adhesive of Comparative Example 1, a high adhesive strength was obtained when the width was 1.5 mm, but sufficient adhesive strength was not obtained when the width was 1.0 mm. With the film-like adhesives of Comparative Examples 2 to 4, sufficient adhesive strength was not obtained even when connected to a width of 1.5 mm.

DESCRIPTION OF SYMBOLS 10 ... Circuit connection member, 10a ... Insulating substance, 10b ... Conductive particle, 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

(A) a thermoplastic resin having a urethane bond;
(B) a radically polymerizable compound;
(C) a radical polymerization initiator;
(D) polyurethane beads;
(E) non-conductive inorganic fine particles;
An adhesive composition comprising:
The adhesive composition according to claim 1, wherein the content of the thermoplastic resin having the (a) urethane bond is not less than the content of the (d) polyurethane beads on a mass basis.
(F) The adhesive composition according to claim 1 or 2, further comprising conductive particles.
The adhesive composition according to any one of claims 1 to 3, which is used for circuit connection.
A structure comprising the adhesive composition according to any one of claims 1 to 4 or a cured product thereof.
A first circuit member having a first circuit electrode;
A second circuit member having a second circuit electrode;
A circuit connecting member disposed between the first circuit member and the second circuit member;
The first circuit electrode and the second circuit electrode are electrically connected;
A structure in which the circuit connecting member includes the adhesive composition according to any one of claims 1 to 4 or a cured product thereof.