WO2022186016A1

WO2022186016A1 - Bonding film for circuit connection and connected body

Info

Publication number: WO2022186016A1
Application number: PCT/JP2022/007383
Authority: WO
Inventors: 譲小林; 直工藤; 翔太三島
Original assignee: 昭和電工マテリアルズ株式会社
Priority date: 2021-03-01
Filing date: 2022-02-22
Publication date: 2022-09-09
Also published as: CN116917429A; TW202239933A; KR20230154877A; JPWO2022186016A1

Abstract

A bonding film for circuit connection, the bonding film being used for the purpose of connecting a first circuit member, which is obtained by forming a first circuit electrode on a main surface of a first substrate, and a second circuit member, which is obtained by forming a second circuit electrode on a main surface of a second substrate, with each other in such a manner that the first circuit electrode and the second circuit electrode face each other. This bonding film for circuit connection contains (a) a thermoplastic resin, (b) a radically polymerizable compound, (c) a radical polymerization initiator and (d) insulating particles; the radically polymerizable compound (b) contains a (meth)acrylate compound; the flow rate of this bonding film is 140% or more as determined at a heating temperature of 160°C under a pressure of 2 MPa with a heating time of 5 seconds; and the linear expansion coefficient of a cured product of this bonding film is 130 ppm/K or less on average for the temperature range 80°C to 90°C.

Description

Adhesive film and connector for circuit connection

The present disclosure relates to an adhesive film for circuit connection and a connection body of circuit members.

In semiconductor devices and liquid crystal display devices, various adhesive compositions have conventionally been used as circuit connecting materials for the purpose of bonding various members in the devices. The adhesive composition is required to have various properties such as heat resistance and reliability under high temperature and high humidity conditions, in addition to adhesiveness.

In recent years, mobile terminals have become smaller, and the development of wearable terminals has also become active. Furthermore, wearable terminals are required to have excellent weather resistance due to their intended use. As the weather resistance, salt water resistance has been required in recent years.

On the other hand, a method has been used to prevent moisture from entering by applying a sealing resin to the circuit connection portion (see Patent Documents 1 and 2, for example).

Japanese Unexamined Patent Application Publication No. 2012-203628 JP-A-2003-151762

However, since wearable terminals are small, the circuit connection part is small and it is often impossible to apply sealing resin. Moreover, even if it can be applied, it is technically difficult, and the problem is that the cost rises. Therefore, in small mobile terminals such as wearable terminals, use of a film-like adhesive (adhesive film) that facilitates sealing even when the circuit connection portion is small is being studied.

However, when an adhesive film is used to bond circuit members together and to seal circuit connections, salt water resistance tends to be insufficient.

The present disclosure has been made in view of the above problems of the prior art, and an adhesive film for circuit connection capable of forming a connection body having excellent salt water resistance, and a circuit member connection body using the same intended to provide

In order to achieve the above object, the present disclosure provides a first circuit member having a first circuit electrode formed on the main surface of a first substrate and a second circuit on the main surface of the second substrate. An adhesive film for circuit connection for connecting a second circuit member having electrodes formed thereon with the first circuit electrode and the second circuit electrode facing each other, wherein the adhesive film is , (a) a thermoplastic resin, (b) a radically polymerizable compound, (c) a radical polymerization initiator, and (d) insulating particles, wherein the (b) radically polymerizable compound is a (meth)acrylate compound The flow rate of the adhesive film is 140% or more at a heating temperature of 160 ° C., a pressure of 2 MPa, and a heating time of 5 seconds, and the linear expansion coefficient of the cured product of the adhesive film is 130 ppm on average at 80 to 90 ° C. /K or less to provide an adhesive film for circuit connection.

According to the adhesive film for circuit connection, since it is in the form of a film, it is possible to easily connect circuit members and seal the circuit connection part in a small mobile terminal such as a wearable terminal, and it has excellent salt resistance. Connections having aqueous properties can be formed. Here, the present inventors speculate as follows about the reason why excellent salt water resistance is obtained. First, chloride ions, which are components of salt water, are more likely to permeate the interface between the circuit member and the connection member, which is a cured adhesive film, than the water component, thereby easily causing separation between the circuit member and the connection member. Therefore, even if the connector does not peel when exposed to normal water, it is likely to peel when exposed to salt water. On the other hand, according to the adhesive film, the linear expansion coefficient of the cured product is within the above range, so that the adhesion of the interface between the circuit member and the connection member is sufficient to prevent the salt water component from permeating. can be increased, and peeling can be suppressed even when the connector is exposed to salt water. Furthermore, according to the adhesive film, the flow rate is within the above range, so that the adhesive film flows when the circuit members are connected to each other and protrudes appropriately from between the circuit members, and the protruding portion is the circuit connection part. It will act as a protective lid. Since the lid portion also has high adhesion to the circuit member, it is possible to prevent salt water components from entering the interface between the circuit member and the connection member. Therefore, according to the adhesive film for circuit connection, it is possible to form a connecting body having excellent resistance to salt water. Moreover, the above effect is maximized when a (meth)acrylate compound is used as the radically polymerizable compound.

The (d) insulating particles may contain silica particles. In addition, the (d) insulating particles may contain organic fine particles. Here, the organic fine particles may contain fine particles made of at least one kind of resin selected from the group consisting of polyurethane resins and silicone resins. Furthermore, the average particle diameter of the (d) insulating particles may be 0.001 to 35 μm. By using these insulating particles, it is easy to adjust the flow rate of the adhesive film and the coefficient of linear expansion of the cured product to a suitable range, and to further improve the resistance to salt water of the obtained connected body.

The circuit connection adhesive film may further contain (e) conductive particles. (e) By containing the conductive particles, the adhesive film for circuit connection can be imparted with conductivity or anisotropic conductivity, so the adhesive film can be more preferably used as a circuit connection material. Moreover, the connection resistance between the circuit electrodes electrically connected via the adhesive film can be more easily reduced.

The present disclosure also includes a pair of circuit members having circuit electrodes and arranged to face each other, and a connection member provided between the pair of circuit members and bonding the pair of circuit members together, The circuit electrode of the circuit member and the circuit electrode of the other circuit member are electrically connected, and the connection member is a cured product of the above adhesive film for circuit connection. Such connectors can have excellent resistance to salt water.

According to the present disclosure, it is possible to provide an adhesive film for circuit connection capable of forming a connection body having excellent salt water resistance, and a circuit member connection body using the same.

1 is a schematic cross-sectional view showing an embodiment of a laminated film having an adhesive film for circuit connection; FIG. 1 is a schematic cross-sectional view showing an embodiment of a connecting body; FIG. It is a schematic sectional drawing which shows one Embodiment of the method of manufacturing a connection body.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings as the case may be. The present disclosure is not limited to the following embodiments. The materials exemplified below may be used singly 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 otherwise specified when there are multiple substances corresponding to each component in the composition. A numerical range indicated using "-" indicates a range including the numerical values before and after "-" as the minimum and maximum values, respectively. In the numerical ranges described stepwise in this specification, the upper limit value or lower limit value of the numerical range at one step may be replaced with the upper limit value or lower limit value of the numerical range at another step. In the numerical ranges described herein, the upper or lower limits of the numerical ranges may be replaced with the values shown in the examples. As used herein, (meth)acrylate means acrylate or its corresponding methacrylate, and (meth)acryloyloxy means acryloyloxy or methacryloyloxy.

The present embodiment relates to the following [1] to [7].
[1] A first circuit member having first circuit electrodes formed on the main surface of a first substrate, and a second circuit having second circuit electrodes formed on the main surface of a second substrate A circuit connection adhesive film for connecting a member with the first circuit electrode and the second circuit electrode facing each other, the adhesive film comprising (a) a thermoplastic resin, ( b) a radically polymerizable compound, (c) a radical polymerization initiator, and (d) insulating particles, wherein the (b) radically polymerizable compound comprises a (meth)acrylate compound, and the flow rate of the adhesive film is 140% or more at a heating temperature of 160 ° C., a pressure of 2 MPa, and a heating time of 5 seconds, and the linear expansion coefficient of the cured product of the adhesive film is 130 ppm / K or less on average at 80 to 90 ° C., for circuit connection. adhesive film.
[2] The adhesive film for circuit connection according to [1] above, wherein the insulating particles (d) contain silica fine particles.
[3] The adhesive film for circuit connection according to [1] or [2] above, wherein the (d) insulating particles contain organic fine particles.
[4] The adhesive film for circuit connection according to [3] above, wherein the organic fine particles contain fine particles made of at least one resin selected from the group consisting of polyurethane resins and silicone resins.
[5] The adhesive film for circuit connection according to any one of [1] to [4] above, wherein the average particle diameter of the (d) insulating particles is 0.001 to 35 μm.
[6] (e) The adhesive film for circuit connection according to any one of [1] to [5] above, which further contains conductive particles.
[7] A pair of circuit members having circuit electrodes arranged opposite to each other, and a connection member provided between the pair of circuit members and bonding the pair of circuit members together, one of the circuit members and the circuit electrode of the other circuit member are electrically connected, and the connection member is the cured adhesive film for circuit connection according to any one of [1] to [6]. A connection that is a thing.

(adhesive film for circuit connection)
The adhesive film for circuit connection according to the present embodiment (hereinafter also simply referred to as "adhesive film") comprises (a) a thermoplastic resin, (b) a radically polymerizable compound, (c) a radical polymerization initiator, and (d) ) containing insulating particles. The (b) radically polymerizable compound includes a (meth)acrylate compound. The flow rate of the adhesive film is 140% or more at a heating temperature of 160° C., a pressure of 2 MPa, and a heating time of 5 seconds. Further, the coefficient of linear expansion (CTE) of the cured adhesive film is 130 ppm/K or less on average at 80 to 90°C. The adhesive film having the above configuration comprises an adhesive composition containing the (a) thermoplastic resin, the (b) radically polymerizable compound, the (c) radical polymerization initiator, and the (d) insulating particles. can be formed using The adhesive film and adhesive composition may also contain (e) conductive particles. Each component will be described below.

(a) The thermoplastic resin is not particularly limited, but for example, one selected from polyimide resin, polyamide resin, phenoxy resin, poly(meth)acrylate resin, polyimide resin, polyester resin, polyurethane resin and polyvinyl butyral resin, Two or more resins are included. The thermoplastic resin may contain siloxane bonds and/or fluorine groups. When two or more thermoplastic resins are used, the combination may be such that they are completely compatible or cause microphase separation to cause white turbidity.

Although the weight average molecular weight of the thermoplastic resin is not particularly limited, it may be 5,000 to 200,000, or 10,000 to 150,000. When the weight average molecular weight of the thermoplastic resin is 5000 or more, the adhesive strength of the adhesive film tends to improve. When the weight average molecular weight of the thermoplastic resin is 200,000 or less, there is a tendency that good compatibility with other components is likely to be obtained, and the fluidity of the adhesive film is likely to be improved.

The content of the thermoplastic resin may be 20 to 80% by mass, 25 to 70% by mass, or 30 to 60% by mass, based on the total amount of components (a) and (b). may be When the content of the thermoplastic resin is 20% by mass or more, the adhesive strength of the adhesive film tends to improve, and the film formability when forming the adhesive film from the adhesive composition tends to improve. If the amount is not more than % by mass, the adhesive film tends to be more fluid.

A rubber component can also be used as the thermoplastic resin for the purpose of relaxing stress and improving adhesion. Examples of rubber components include acrylic rubber, polyisoprene, polybutadiene, carboxyl-terminated polybutadiene, hydroxyl-terminated polybutadiene, 1,2-polybutadiene, carboxyl-terminated 1,2-polybutadiene, hydroxyl-terminated 1,2-polybutadiene, and styrene-butadiene rubber. , hydroxyl-terminated styrene-butadiene rubber, carboxylated nitrile rubber, hydroxyl-terminated poly(oxypropylene), alkoxysilyl-terminated poly(oxypropylene), poly(oxytetramethylene) glycol, polyolefin glycol and poly-ε-caprolactone. . From the viewpoint of improving adhesiveness, the rubber component may have a cyano group or a carboxyl group, which are highly polar groups, as side chain groups or terminal groups. These rubber components can be used individually by 1 type or in combination of 2 or more types.

The adhesive film according to the present embodiment may contain any radically polymerizable compound (b), but it contains at least a (meth)acrylate compound. This radically polymerizable compound may be either a monomer or an oligomer, or a combination of both.

The radically polymerizable compound may be one or more polyfunctional (meth)acrylate compounds having two or more (meth)acryloyloxy groups. Such (meth)acrylate compounds are, for example, monomers or oligomers such as epoxy (meth)acrylates, urethane (meth)acrylates, polyether (meth)acrylates and polyester (meth)acrylates, trimethylolpropane tri(meth)acrylate , polyethylene glycol di(meth)acrylate, polyalkylene glycol di(meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, neopentyl glycol di(meth)acrylate, dipentaerythritol hexa (Meth) acrylate, isocyanuric acid-modified bifunctional (meth) acrylate, isocyanuric acid-modified tri-functional (meth) acrylate, epoxy (meth) produced by addition of (meth) acrylic acid to two glycidyl groups of bisphenol fluorenediglycidyl ether ) acrylates, and compounds obtained by adding ethylene glycol and/or propylene glycol to two glycidyl groups of bisphenol fluorenediglycidyl ether and introducing a (meth)acryloyloxy group. These compounds may be used individually by 1 type, and may combine 2 or more types.

The adhesive film may contain a monofunctional (meth)acrylate compound as the (b) radically polymerizable compound for the purpose of adjusting fluidity and the like. Monofunctional (meth)acrylate compounds include, for example, pentaerythritol (meth)acrylate, 2-cyanoethyl (meth)acrylate, cyclohexyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate , 2-(2-ethoxyethoxy)ethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-hexyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, hydroxy propyl (meth)acrylate, isobornyl (meth)acrylate, isodecyl (meth)acrylate, isooctyl (meth)acrylate, n-lauryl (meth)acrylate, 2-methoxyethyl (meth)acrylate, 2-phenoxyethyl (meth)acrylate, Tetrahydrofurfuryl (meth)acrylate, 2-(meth)acryloyloxyethyl phosphate, N,N-dimethylaminoethyl (meth)acrylate, N,N-dimethylaminopropyl (meth)acrylate, and (meth)acryloylmorpholine mentioned. These compounds may be used individually by 1 type, and may combine 2 or more types.

For the purpose of improving the cross-linking rate, etc., the adhesive film contains, in addition to the above (meth)acrylate compound, a radically polymerizable functional group such as an aryl group, a maleimide group, and a vinyl group as the (b) radically polymerizable compound. It may contain a compound having Such compounds are, for example, N-vinylimidazole, N-vinylpyridine, N-vinylpyrrolidone, N-vinylformamide, N-vinylcaprolactam, 4,4′-vinylidenebis(N,N-dimethylaniline), N -vinylacetamide, N,N-dimethylacrylamide, N-isopropylacrylamide and N,N-diethylacrylamide.

The adhesive film may contain a radically polymerizable compound having a phosphoric acid group as (b) a radically polymerizable compound for the purpose of improving adhesive strength. Examples of radically polymerizable compounds having a phosphoric acid group include compounds represented by the following formulas (1), (2), and (3).

In formula (1), R ⁵ represents a (meth)acryloyloxy group, R ⁶ represents a hydrogen atom or a methyl group, and w and x each independently represents an integer of 1-8. Plural R ⁵ , R ⁶ , w and x in the same molecule may be the same or different.

In formula (2), R ⁷ represents a (meth)acryloyloxy group, and y and z each independently represents an integer of 1-8. Plural R ⁷ , y and z in the same molecule may be the same or different.

In formula (3), R ⁸ represents a hydrogen atom or a methyl group, R ⁹ represents a (meth)acryloyloxy group, and b and c each independently represent an integer of 1-8. R8 ⁱⁿ the same molecule may be the same or different.

Radically polymerizable compounds having a phosphoric acid group include, for example, acid phosphooxyethyl methacrylate, acid phosphooxyethyl acrylate, acid phosphooxypropyl methacrylate, acid phosphooxypolyoxyethylene glycol monomethacrylate, acid phosphooxypolyoxypropylene glycol monomethacrylate. , 2,2′-di(meth)acryloyloxydiethyl phosphate, EO-modified dimethacrylate phosphate, phosphate-modified epoxy acrylate and vinyl phosphate.

The content of the radically polymerizable compound having a phosphoric acid group may be 0.1 to 15% by mass, or 0.5 to 10% by mass, based on the total amount of components (a) and (b). There may be. If the content of the radically polymerizable compound having a phosphate group is 0.1% by mass or more, high adhesive strength tends to be obtained, and if it is 15% by mass or less, the physical properties of the adhesive film after curing deteriorate. is less likely to occur, and the effect of improving reliability is good.

The total content of the (b) radically polymerizable compound contained in the adhesive film may be 20 to 80% by mass, preferably 25 to 70% by mass, based on the total amount of components (a) and (b). It may be present, and may be 30 to 60% by mass. When the total content is 20% by mass or more, the heat resistance tends to be improved, and when the total content is 80% by mass or less, the effect of suppressing peeling after being left in a high-temperature and high-humidity environment tends to increase.

(c) The radical polymerization initiator can be arbitrarily selected from compounds such as peroxides and azo compounds. From the viewpoint of stability, reactivity and compatibility, a peroxide having a 1-minute half-life temperature of 90 to 175° C. and a molecular weight of 180 to 1,000 may be used. "1 minute half-life temperature" refers to the temperature at which the peroxide half-life is 1 minute. "Half-life" refers to the time it takes for the concentration of a compound to decrease to half of its initial value at a given temperature.

Radical polymerization initiators include, for example, 1,1,3,3-tetramethylbutyl peroxyneodecanoate, di(4-t-butylcyclohexyl)peroxydicarbonate, di(2-ethylhexyl)peroxydicarbonate , cumyl peroxyneodecanoate, 1,1,3,3-tetramethylbutyl peroxyneodecanoate, dilauroyl peroxide, 1-cyclohexyl-1-methylethyl peroxyneodecanoate, t-hexyl peroxyneodecanoate, t-butyl peroxyneodecanoate, t-butyl peroxypivalate, 1,1,3,3-tetramethylbutyl peroxy-2-ethylhexanoate, 2,5- Dimethyl-2,5-di(2-ethylhexanoylperoxy)hexane, t-hexylperoxy-2-ethylhexanoate, t-butylperoxy-2-ethylhexanoate, t-butylperoxyneo Heptanoate, t-amylperoxy-2-ethylhexanoate, di-t-butylperoxyhexahydroterephthalate, t-amylperoxy-3,5,5-trimethylhexanoate, 3-hydroxy-1 ,1-dimethylbutyl peroxyneodecanoate, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, t-amylperoxyneodecanoate, t-amylperoxy-2 -ethylhexanoate, 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) ronitrile), dimethyl-2,2'-azobisisobutyronitrile, 4,4'-azobis(4-cyanovaleric acid), 1,1'-azobis(1-cyclohexanecarbonitrile), t-hexylperoxy isopropyl monocarbonate, t-butyl peroxymaleic acid, t-butyl peroxy-3,5,5-trimethylhexanoate, t-butyl peroxylaurate, 2,5-dimethyl-2,5-di(3 -methylbenzoylperoxy)hexane, t-butylperoxy-2-ethylhexyl monocarbonate t, t-hexyl peroxybenzoate, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, t-butyl peroxybenzoate, dibutyl peroxytrimethyl adipate, t-amyl peroxy normal octoate, t -amyl peroxyisononanoate and t-amyl peroxybenzoate. These can be used individually by 1 type or in combination of 2 or more types.

A compound that generates radicals upon irradiation with light having a wavelength of 150 to 750 nm can also be used as the radical polymerization initiator. Such compounds are not particularly limited. -P. α-acetaminophenone derivatives and phosphine oxide derivatives described in Fouassier, Hanser Publishers (1995), pp.17-35. These compounds are used individually by 1 type or in combination of 2 or more types. These compounds may be combined with the above peroxides and azo compounds. Alternatively, the adhesive film may contain a radical polymerization initiator that generates radicals by ultrasonic waves, electromagnetic waves, or the like.

The amount of chlorine ions or organic acid contained in the radical polymerization initiator may be 5000 ppm or less in order to suppress corrosion of the connection terminals (circuit electrodes) of the circuit members. From the same point of view, it may be a radically polymerizable compound that generates less organic acid after decomposition. It may be 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 and normal pressure because it improves the stability of the circuit connecting material.

The content of the radical polymerization initiator may be 0.5 to 15 parts by mass, or 1.5 to 10 parts by mass, with respect to 100 parts by mass of the total amount of components (a) and (b). good too.

The adhesive film contains (d) insulating particles. The insulating particles include organic fine particles and inorganic fine particles.

Examples of inorganic fine particles include metal oxide fine particles represented by silica fine particles, alumina fine particles, silica-alumina fine particles, titania fine particles and zirconia fine particles, and nitride fine particles.

Examples of organic fine particles include urethane fine particles, silicone fine particles, methacrylate-butadiene-styrene fine particles, acryl-silicone fine particles, polyamide fine particles and polyimide fine particles. The organic fine particles have a function as a shock absorbing agent having stress relaxation properties.

These insulating particles may have a uniform structure or a core-shell structure.

The insulating particles can be used singly or in combination of two or more. As the insulating particles, inorganic fine particles and organic fine particles may be used in combination. By using the inorganic fine particles and the organic fine particles in combination, there is a tendency that the salt water resistance of the connecting body formed using the adhesive film can be further improved.

The average particle diameter of the insulating particles may be 0.001-35 μm, 0.005-20 μm, or 0.001-10 μm. When the average particle size is 0.001 μm or more, the cohesive force of the insulating particles tends to improve, and when the average particle size is 35 μm or less, the dispersibility of the insulating particles tends to improve.

The average particle size in this specification can be measured, for example, with a scanning electron microscope (SEM).

The content of the insulating particles may be 5 parts by mass or more, 7.5 parts by mass or more, or 10 parts by mass with respect to 100 parts by mass as the total amount of components (a) and (b). parts or more, 15 parts by mass or more, or 20 parts by mass or more. If the content of the insulating particles is 5 parts by mass or more, it tends to be relatively easy to maintain the electrical connection between the facing electrodes. In addition, the content of the insulating particles may be 45 parts by mass or less, 40 parts by mass or less, or 35 parts by mass with respect to the total amount of 100 parts by mass of the components (a) and (b). It may be less than part. If the content of the insulating particles is 45 parts by mass or less, the fluidity of the adhesive film tends to improve. Also, the type and content of the insulating particles affect the flow rate and coefficient of linear expansion of the adhesive film. Therefore, the type and content of the insulating particles may be adjusted so that the flow rate and coefficient of linear expansion of the adhesive film are within specific ranges.

The adhesive film according to this embodiment may contain a silane coupling agent. The silane coupling agent may be a compound represented by the following formula (4).

In formula (4), 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 represents an aryl group. At least one of R ¹ , R ² and R ³ is an alkoxy group. ^R4 is a (meth)acryloyl group, vinyl group, isocyanate group, imidazole group, mercapto group, amino group, methylamino group, dimethylamino group, benzylamino group, phenylamino group, cyclohexylamino group, morpholino group, piperazino group, It represents a ureido group or a glycidyl group. a represents an integer of 1 to 10;

Silane coupling agents of formula (4) are, for example, vinyltrimethoxysilane, vinyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-methacryloxypropylmethyl Dimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, N-2 (aminoethyl) 3-amino Propylmethyldimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, and 3-isocyanatopropyltriethoxysilane.

The content of the silane coupling agent may be 0.1 to 10 parts by mass, or 0.25 to 7 parts by mass, with respect to 100 parts by mass of the total amount of components (a) and (b). may be 0.5 to 5 parts by mass. If the content of the silane coupling agent is 0.1 parts by mass or more, the effect of suppressing the generation of peeling bubbles at the interface between the circuit member and the circuit connecting material tends to be greater, and the content of the silane coupling agent tends to be greater. When the content is 10 parts by mass or less, there is a tendency to easily suppress deterioration in fluidity when the adhesive film is stored for a long period of time.

The adhesive film according to the present embodiment may further contain (e) conductive particles. An adhesive film containing conductive particles can be particularly suitably used as an anisotropically conductive adhesive film.

Examples of conductive particles include metal particles containing Au, Ag, Pd, Ni, Cu, solder, etc., and carbon particles. The conductive particles are composite particles having core particles made of a non-conductive material such as glass, ceramic, plastic, etc., and a conductive layer containing a metal, metal particles, carbon, etc. covering the core particles. There may be. The metal particles may be particles having copper particles and a silver layer coating the copper particles. The core particles of the composite particles may be plastic particles.

Since the composite particles having the plastic particles as the core particles have the deformability of being deformed by heat and pressure, when the circuit members are bonded together, the contact area between the circuit electrodes of the circuit members and the conductive particles can be increased. Therefore, with an adhesive film containing these composite particles as conductive particles, it is possible to obtain a connected body that is even more excellent in terms of connection reliability.

The adhesive film may contain insulating coated conductive particles having the above conductive particles and an insulating layer or insulating particles covering at least part of the surface thereof. 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 polymeric resin. By using such insulating-coated conductive particles, short circuits due to contact between adjacent conductive particles are less likely to occur.

The average particle size of the conductive particles may be 1 to 18 μm from the viewpoint of obtaining good dispersibility and conductivity. In this specification, for 300 arbitrary conductive particles (pcs), the particle size is measured by observation using a scanning electron microscope (SEM), and the average value of the obtained particle sizes is taken as the average particle size. .

The content of the conductive particles is not particularly limited, but may be 0.1 to 30% by volume, 0.1 to 10% by volume, or 0.1 to 10% by volume based on the total volume of the adhesive film. It may be 5 to 7.5% by volume. If the content of the conductive particles is 0.1% by volume or more, the conductivity tends to improve. If the content of the conductive particles is 30% by volume or less, short circuits between circuit electrodes tend to be less likely to occur. The content (% by volume) of the conductive particles is determined based on the volume at 23° C. of each component constituting the adhesive film before curing or the adhesive composition before curing. The volume of each component can be determined by converting mass into volume using specific gravity. An appropriate solvent (water, alcohol, etc.) that can wet the component well without dissolving or swelling the component whose volume is to be measured is placed in a graduated cylinder or the like, and the component to be measured is introduced into it. It is also possible to obtain the volume increased by

The adhesive film can contain stabilizers to control the curing speed and provide storage stability. Examples of such stabilizers include, but are not limited to, quinone derivatives such as benzoquinone and hydroquinone, phenol derivatives such as 4-methoxyphenol and 4-t-butylcatechol, and 2,2,6,6-tetramethylpiperidine. -1-oxyl and aminoxyl derivatives such as 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl, and hindered amine derivatives such as tetramethylpiperidyl methacrylate.

The content of the stabilizer may be 0.01 to 30 parts by mass, or 0.05 to 10 parts by mass with respect to 100 parts by mass of the total amount of components (a) and (b). good. When the content of the stabilizer is 0.01 part by mass or more, the effect of the stabilizer tends to increase. When the content of the stabilizer is 30 parts by mass or less, there is a tendency that the decrease in compatibility with other components can be suppressed.

The adhesive film according to the present embodiment is a film-like adhesive obtained by molding the adhesive composition containing the components described above into a film. The adhesive film can be obtained, for example, by applying a solution obtained by adding a solvent or the like to the adhesive composition as necessary on a release support such as a fluororesin film, polyethylene terephthalate film, or release paper, or It can be obtained by a method of impregnating a base material such as a non-woven fabric with the above solution, placing the base material on a peelable base material, and removing the solvent and the like. Adhesive films are convenient in terms of handleability and the like.

The flow rate of the adhesive film according to this embodiment is 140% or more at a heating temperature of 160°C, a pressure of 2 MPa, and a heating time of 5 seconds. When the flow rate of the adhesive film is 140% or more, the adhesive film flows when the circuit members are connected to each other and protrudes moderately from between the circuit members, and the protruding portion serves as a lid to protect the circuit connection part. be able to. Therefore, the connection body obtained using the adhesive film according to the present embodiment can prevent salt water components from entering the interface between the circuit member and the connection member, and has excellent salt water resistance. From the viewpoint of further improving the above effects, the adhesive film may have a flow rate of 145% or more. The flow rate of the adhesive film can be measured by the method shown in Examples.

The coefficient of linear expansion (CTE) of the cured product of the adhesive film according to this embodiment is 130 ppm/K or less on average at 80 to 90°C. When the cured product of the adhesive film has a CTE of 130 ppm/K or less, the adhesiveness of the interface between the circuit member and the connection member is increased to the extent that the infiltration of salt water components can be prevented when the connection body is formed. Thus, even when the connection body is exposed to salt water, it is possible to suppress the occurrence of detachment. From the viewpoint of further improving the above effects, the cured product of the adhesive film may have a CTE of 128 ppm/K or less. The CTE of the cured product of the adhesive film can be measured by the method shown in Examples.

FIG. 1 is a schematic cross-sectional view showing one embodiment of a laminated film having an adhesive film. A laminated film 100 shown in FIG. 1 has a support 8 and an adhesive film 40 provided on the support 8 . The adhesive film 40 is the above-described adhesive composition formed into a film, and is composed of an insulating adhesive layer 5 and insulating particles 6 and conductive particles 7 dispersed in the insulating adhesive layer 5. be done. The insulating adhesive layer 5 is composed of components other than the insulating particles and the conductive particles in the adhesive composition described above. This adhesive film is easy to handle, can be easily installed on an adherend, and can be easily connected. The adhesive film may have a multilayer construction consisting of two or more layers. The adhesive film may not contain conductive particles, but when the adhesive film contains conductive particles, the adhesive film can be suitably used as an anisotropically conductive film.

According to the adhesive film according to the present embodiment, the adherends can be adhered to each other by using both heating and pressure. Although the heating temperature is not particularly limited, it may be 100 to 250°C. The pressure is not particularly limited as long as it does not damage the adherend, but generally it may be 0.1 to 10 MPa. These heating and pressurization may be performed within the range of 0.5 seconds to 120 seconds. According to the adhesive film according to the present embodiment, for example, it is possible to sufficiently bond the adherends together under the conditions of 140 to 200° C. and 1 MPa for a short time of heating and pressing for 5 seconds. .

The adhesive film according to this embodiment can be used as an adhesive for different types of adherends with different thermal expansion coefficients. Specifically, it is used as an anisotropic conductive adhesive, a circuit connection material represented by silver paste and silver film, or a semiconductor element adhesive material represented by elastomer for CSP, underfill material for CSP, and LOC tape. Film can be used.

Hereinafter, using the adhesive film according to the present embodiment as an anisotropic conductive film, a circuit board and circuit members having circuit electrodes formed on the main surface of the circuit board are connected as adherends, An example of manufacturing will be described.

FIG. 2 is a schematic cross-sectional view showing one embodiment of a connecting body provided with a connecting member made of a cured adhesive film according to this embodiment. The connection body 1 shown in FIG. 2 includes a first circuit member 20 and a second circuit member 30 that are arranged to face each other. A connection member 10 is provided between the first circuit member 20 and the second circuit member 30 to adhere and connect them.

The first circuit member 20 includes a first circuit board 21 and first circuit electrodes 22 formed on the main surface 21 a of the circuit board 21 . An insulating layer may be formed on the main surface 21 a of the circuit board 21 .

The second circuit member 30 includes a second circuit board 31 and second circuit electrodes 32 formed on the main surface 31 a of the circuit board 31 . An insulating layer may also be formed on the main surface 31 a of the circuit board 31 .

The first and

second circuit members

20, 30 are not particularly limited as long as they have circuit electrodes that require electrical connection. Examples of the

circuit boards

21 and 31 include substrates of inorganic materials such as semiconductors, glass and ceramics, substrates of organic materials such as polyimide and polycarbonate, and substrates containing inorganic and organic materials such as glass/epoxy. The first circuit board 21 may be a glass board, and the second circuit board 31 may be a flexible board (for example, a resin film such as a polyimide film).

Specific examples of circuit members to be connected include glass or plastic substrates, printed wiring boards, ceramic wiring boards, and flexible wiring boards on which electrodes such as ITO (indium tin oxide) films are formed, which are used in liquid crystal displays. , semiconductor silicon chips, and the like. These are used in combination as necessary. Thus, according to the adhesive film according to the present embodiment, in addition to members having surfaces formed of organic materials such as printed wiring boards and polyimide films, metals such as copper and aluminum, ITO, silicon nitride (SiN _x ), and members having surfaces formed from inorganic materials such as silicon dioxide ( _SiO2 ).

For example, when one circuit member is a solar cell having electrodes such as finger electrodes and busbar electrodes, and the other circuit member is a tab wire, the connection body obtained by connecting these is the solar cell, The solar cell module includes tab wires and a connecting member (cured product of an adhesive film) for bonding them.

The connection member 10 is made of a cured adhesive film according to this embodiment. The connection member 10 contains an insulating layer 11 and conductive particles 7 dispersed in the insulating layer 11 . The conductive particles 7 are arranged not only between the opposing

circuit electrodes

22 and 32, but also between the

major surfaces

21a and 31a. The

circuit electrodes

22 , 32 are electrically connected via the conductive particles 7 . Conductive particles 7 are in direct contact with both

circuit electrodes

22 and 32 . Therefore, the connection resistance between the

circuit electrodes

22 and 32 is sufficiently reduced. Therefore, the current flow between the

circuit electrodes

22 and 32 can be made smooth, and the functions of the circuit can be fully exhibited. When the connection member does not contain conductive particles, the circuit electrodes 22 and the circuit electrodes 32 are electrically connected by direct contact.

Since the connection member 10 is formed of the cured adhesive film according to this embodiment, the adhesion strength of the connection member 10 to the

circuit member

20 or 30 is sufficiently high. Therefore, even after a reliability test (high-temperature, high-humidity test), it is possible to sufficiently suppress a decrease in adhesive strength and an increase in connection resistance.

The connection body 1 is formed by, for example, a step of arranging a pair of circuit members having circuit electrodes and facing each other with an adhesive film made of an adhesive composition sandwiched therebetween, and bonding the pair of circuit members and the adhesive film. It can be manufactured by a method comprising a step of bonding a pair of circuit members via the cured adhesive film (main connecting step) by heating and curing while applying pressure to the film in the thickness direction.

FIG. 3 is a schematic cross-sectional view showing one embodiment of a method for manufacturing a connected body using the adhesive film according to this embodiment. As shown in (a) of FIG. 3, an adhesive film 40 is placed on the main surface of the first circuit member 20 on the circuit electrode 22 side. When the adhesive film 40 is provided on the support described above, the laminate of the adhesive film and the support is placed on the circuit member such that the adhesive film 40 faces the first circuit member 20 . Since the adhesive film 40 is in the form of a film, it is easy to handle. Therefore, the adhesive film 40 can be easily interposed between the first circuit member 20 and the second circuit member 30, and the work of connecting the first circuit member 20 and the second circuit member 30 can be performed. can be easily done.

The adhesive film 40 is the above-described adhesive composition (circuit connecting material) formed into a film, and has insulating particles 6 , conductive particles 7 and an insulating adhesive layer 5 . Even if the adhesive film does not contain conductive particles, it can be used as a circuit connecting material for anisotropic conductive adhesion. A circuit-connecting material that does not contain conductive particles is sometimes called an NCF (Non-Conductive Film). When the adhesive film contains conductive particles, the circuit connecting material using this is sometimes called ACF (Anisotropic Conductive Film).

The thickness of the adhesive film 40 may be 10-50 μm. If the thickness of the adhesive film 40 is 10 μm or more, the space between the

circuit electrodes

22 and 32 tends to be easily filled with the adhesive film. If the thickness of the adhesive film is 50 μm or less, the adhesive film between the

circuit electrodes

22 and 32 can be sufficiently removed, and the electrical connection between the

circuit electrodes

22 and 32 can be easily secured.

The adhesive film 40 is temporarily connected to the first circuit member 20 by applying pressures A and B in the thickness direction of the adhesive film 40 as shown in FIG. ). At this time, the pressure may be applied while heating. However, the heating temperature is set to a temperature at which the adhesive composition in the adhesive film 40 does not cure, that is, a temperature sufficiently lower than the temperature at which the radical polymerization initiator rapidly generates radicals.

Subsequently, as shown in (c) of FIG. 3, the second circuit member 30 is placed on the adhesive film 40 with the second circuit electrode facing the first circuit member 20 side. When the adhesive film 40 is provided on the support, the second circuit member 30 is placed on the adhesive film 40 after peeling off the support.

After that, the adhesive film 40 is heated while applying pressures A and B in its thickness direction. The heating temperature at this time is set to a temperature at which the radical polymerization initiator sufficiently generates radicals. As a result, radicals are generated from the radical polymerization initiator, and polymerization of the radically polymerizable compound is initiated. By heating the adhesive film 40 , the insulating adhesive is cured to form the insulating layer 11 while the distance between the first circuit electrode 22 and the second circuit electrode 32 is sufficiently reduced. As a result, the first circuit member 20 and the second circuit member 30 are firmly connected via the connection member 10 including the insulating layer 11 . With this permanent connection, the connection body shown in FIG. 2 is obtained.

This connection may be performed under the conditions of a heating temperature of 100 to 250°C, a pressure of 0.1 to 10 MPa, and a pressurization time of 0.5 to 120 seconds. These conditions are appropriately selected depending on the intended use, adhesive film, and circuit member. Post-curing may be performed after the main connection, if necessary.

The pressure of this connection is calculated from the applied load and the crimped area by the formula: load/crimped area. The crimping area is the area of the portion to be pressed among the smallest rectangular regions surrounding the entire overlapping portion of the first circuit electrode and the second circuit electrode when viewed from the thickness direction of the adhesive film. .

When the adhesive film contains a radical polymerization initiator that generates radicals upon irradiation with light, light irradiation may be performed instead of heating when curing the adhesive film for this connection. Also, instead of the adhesive film prepared in advance, for example, a paste-like adhesive composition may be used as the circuit connecting material. For example, a coating liquid prepared by dissolving the adhesive composition in a solvent if necessary is applied to the first circuit member 20 or the second circuit member 30, and the adhesive film is formed by a method including the step of drying the coating film. can be formed.

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

(Synthesis of polyurethane resin)
A separable flask equipped with a reflux condenser, a thermometer and a stirrer was charged with 1000 parts by mass of polypropylene glycol (Mn = 2000), which is a diol having an ester bond, and 4000 parts by mass of methyl ethyl ketone as a solvent, and the mixture was heated at 40°C for 30 minutes. Stirred. After heating the solution to 70° C., 0.0127 parts by mass of dimethyltin laurate as a catalyst was added. Then, a solution prepared by dissolving 125 parts by mass of 4,4-diphenylmethane-diisocyanate as a diisocyanate compound in 125 parts by mass of methyl ethyl ketone was added dropwise to this solution over 1 hour. Thereafter, stirring was continued at this temperature until no absorption peak of NCO was observed with an infrared spectrophotometer to obtain a methyl ethyl ketone solution of polyurethane resin. The solid content concentration (polyurethane resin concentration) of this solution was adjusted to 30% by mass. The weight average molecular weight of the obtained polyurethane resin was 320000 (standard polystyrene conversion value) as a result of measurement by GPC. The analysis conditions for GPC are shown in Table 1 below.

(Synthesis of urethane acrylate)
A 2-liter four-necked flask equipped with a thermometer, a stirrer, an inert gas inlet, and a reflux condenser was charged with 4000 parts by mass of polycarbonate diol (manufactured by Aldrich, number average molecular weight 2000) and 2-hydroxyethyl acrylate. 238 parts by mass, 0.49 parts by mass of hydroquinone monomethyl ether, and 4.9 parts by mass of a tin-based catalyst were charged to prepare a reaction solution. To the reaction solution heated to 70° C., 666 parts by mass of isophorone diisocyanate (IPDI) was uniformly added dropwise over 3 hours to react. After the completion of dropping, the reaction was continued for 15 hours, and when it was confirmed that the NCO content was 0.2% by mass or less with an automatic potentiometric titrator (trade name: AT-510, manufactured by Kyoto Electronics Industry Co., Ltd.). The reaction was terminated to obtain urethane acrylate. As a result of GPC analysis, 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 resin described above.

(Preparation of conductive particles)
A nickel layer with a thickness of 0.2 μm was formed on the surface of the polystyrene particles, and a gold layer with a thickness of 0.04 μm was further formed on the outside of this nickel layer. In this way, conductive particles having an average particle size of 5 μm were produced.

[Examples 1 to 5 and Comparative Examples 1 to 3]
(Preparation of laminated film having adhesive film)
The raw materials shown in Table 2 were mixed at the mass ratio (solid content mass ratio) shown in Table 2 to obtain a coating liquid for forming an adhesive film. 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 form an adhesive film with a thickness of 16 μm. As a result, a laminated film was obtained in which the adhesive film was laminated on the PET film as the support.

The details of each component shown in Table 2 are as follows.
((a) component: thermoplastic resin)
Polyurethane resin: The 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 Co., Ltd., trade name, weight average molecular weight: 45000) in 60 g of methyl ethyl ketone.
((b) component: radically polymerizable compound)
Urethane acrylate: The urethane acrylate synthesized as described above was used.
Phosphate acrylate: P-2M (Kyoeisha Chemical Co., Ltd., trade name)
((c) component: radical polymerization initiator)
Peroxide: 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate (trade name: Perocta O, manufactured by NOF Corporation, 1 minute half-life temperature: 124.3 ° C.) board.
((d) component: insulating particles)
Silica fine particles: R104 (manufactured by Nippon Aerosil Co., Ltd., trade name, average particle size: 12 nm) was dispersed in a mixed solvent of 45 g of toluene and 45 g of ethyl acetate, and used in the form of a dispersion having a solid content of 10% by mass.
Organic fine particles A: 10 g of BTA 751 (manufactured by Rohm and Haas, trade name, core-shell type fine particles, average particle diameter: 0.2 to 0.3 μm) dispersed in 90 g of methyl ethyl ketone, dispersion liquid having a solid content of 10% by mass. used in the form of
Organic fine particles B: CE-800T (manufactured by Negami Kogyo Co., Ltd., trade name, polyurethane beads, average particle size: 6 μm) 10 g were dispersed in 90 g of methyl ethyl ketone, and used in the form of a dispersion having a solid content of 10% by mass.
((e) component: conductive particles)
Conductive particles: Conductive particles prepared as described above were used.
(Other ingredients)
Silane coupling agent: KBM-503 (manufactured by Shin-Etsu Chemical Co., Ltd., trade name)

(Production of connecting body)
A flexible circuit board (FPC) having 220 copper circuits with a line width of 75 μm, a pitch of 150 μm, and a thickness of 18 μm was connected to a glass substrate using the above adhesive film as a circuit connecting material. The connection was performed by heating and pressurizing at 160° C. and 2 MPa for 5 seconds using a thermocompression bonding device (heating method: constant heat type, manufactured by Nikka Setsubi Engineering Co., Ltd.). As a result, a connected body in which the FPC and the glass substrate were connected by the cured adhesive film over a width of 1.2 mm was produced.

(Measurement of average linear expansion coefficient (CTE))
A plurality of the above adhesive films were laminated using a laminator so as to have a thickness of 100±20 μm, and then cured by heating in an oven at 180° C. for 1 hour to prepare a cured product sample. The linear expansion coefficient of the obtained cured product sample was measured using a thermal expansion coefficient measuring device (manufactured by Hitachi High-Tech Science Co., Ltd.), the sample length was 10 mm and the width was 5 mm, the measurement mode was the tensile mode, and the load was the cross-sectional area (mm ² ) multiplied by 163.4 mN/mm ² , the temperature range was -5 to 250°C, and the heating rate was 5°C per minute. The average coefficient of linear expansion (CTE) at 80 to 90° C. was read from the measurement results.

(Measurement of flow rate)
The adhesive film was punched out into a circle with a diameter of 1.0 mm, sandwiched between cover glasses (manufactured by AS ONE Corporation) to form a test piece, and a photograph of the adhesive film portion was taken using a microscope (manufactured by Nikon Corporation) and image analysis was performed. The area A1 of the adhesive film was measured using soft NIS-Elements D (manufactured by Nikon Corporation). Then, using a flip chip bonder FCB3 (manufactured by Panasonic Corporation), heating and pressing were performed at 160° C. and 2 MPa for 5 seconds, and the area A2 of the adhesive film was measured in the same manner. The flow rate was calculated from the rate of change in the area of the adhesive film before and after heating and pressing (see the formula below).
Flow rate (%) = (A2/A1) x 100

(Evaluation of salt water resistance)
The connector prepared as described above was immersed in an aqueous solution of NaCl adjusted to a concentration of 5% by mass under conditions of 25° C. for 12 hours and then dried. This was confirmed using ECLIPSE L200 (manufactured by Nikon Corporation). Of the total area of the circuit connection part, the ratio of peeling from the circuit member (FPC and glass substrate) is determined, and A is for no peeling, and a small amount of peeling is occurring (the ratio of the peeled part is the total area (less than 20% of the total area) was rated B, and C was rated when peeling occurred (the percentage of the peeled portion was 20% or more of the total area). Table 2 shows the results.

As is clear from the results shown in Table 2, according to the adhesive films of Examples, the flow rate is 140% or more at a heating temperature of 160° C., a pressure of 2 MPa, and a heating time of 5 seconds, and the CTE is 80 to 80%. It was confirmed that an average of 130 ppm/K or less at 90° C. exhibits excellent salt water resistance. On the other hand, it was confirmed that when the flow rate is less than 140% or the CTE is greater than 130 ppm/K, excellent saltwater resistance cannot be obtained.

DESCRIPTION OF SYMBOLS 1... Connector 5... Insulating adhesive layer 6... Insulating particle 7... Conductive particle 8... Support 10... Connecting member 11... Insulating layer 20... First circuit member 21... First circuit board 21a Main surface 22 First circuit electrode 30 Second circuit member 31 Second circuit board 31a Main surface 32 Second circuit electrode 40 Adhesive film, 100... Laminated film.

Claims

A first circuit member having a first circuit electrode formed on the main surface of a first substrate and a second circuit member having a second circuit electrode formed on the main surface of a second substrate , a circuit connection adhesive film for connecting the first circuit electrode and the second circuit electrode in a state of facing each other,
The adhesive film contains (a) a thermoplastic resin, (b) a radical polymerizable compound, (c) a radical polymerization initiator, and (d) insulating particles,
The (b) radically polymerizable compound includes a (meth)acrylate compound,
The flow rate of the adhesive film is 140% or more at a heating temperature of 160° C., a pressure of 2 MPa, and a heating time of 5 seconds, and the linear expansion coefficient of the cured product of the adhesive film is 130 ppm/K or less on average at 80 to 90° C. An adhesive film for circuit connection.
The adhesive film for circuit connection according to claim 1, wherein the (d) insulating particles contain silica fine particles.
The adhesive film for circuit connection according to claim 1 or 2, wherein the (d) insulating particles contain organic fine particles.
The adhesive film for circuit connection according to claim 3, wherein the organic fine particles contain fine particles made of at least one kind of resin selected from the group consisting of polyurethane resins and silicone resins.
The adhesive film for circuit connection according to any one of claims 1 to 4, wherein the (d) insulating particles have an average particle diameter of 0.001 to 35 µm.
The adhesive film for circuit connection according to any one of claims 1 to 5, further comprising (e) conductive particles.
A pair of circuit members having circuit electrodes and arranged facing each other, and a connection member provided between the pair of circuit members and bonding the pair of circuit members, wherein the circuit of one of the circuit members The electrode and the circuit electrode of the other circuit member are electrically connected, and the connection member is a cured product of the adhesive film for circuit connection according to any one of claims 1 to 6, connection.