WO2022102672A1

WO2022102672A1 - Adhesive film for circuit connection, method for manufacturing same, connection structure body, and method for manufacturing same

Info

Publication number: WO2022102672A1
Application number: PCT/JP2021/041394
Authority: WO
Inventors: 敏光森谷; 邦彦赤井; 剛幸市村
Original assignee: 昭和電工マテリアルズ株式会社
Priority date: 2020-11-12
Filing date: 2021-11-10
Publication date: 2022-05-19
Also published as: JPWO2022102672A1; CN116685652A; TW202229487A; KR20230107273A

Abstract

A method of manufacturing an adhesive film for circuit connection, the method comprising: preparing a substrate having a plurality of recesses on a surface thereof and having conductive particles in at least a portion of the plurality of recesses; providing, on the surface of the substrate, a composition layer containing a photosetting component and a first thermosetting component to transfer the conductive particles to the composition layer; irradiating the composition layer with light to form a first adhesive layer containing the conductive particles, a cured product of the photosetting component, and the first thermosetting component; and providing, on one surface of the first adhesive layer, a second adhesive layer containing a second thermosetting component.

Description

Adhesive film for circuit connection and its manufacturing method, and connection structure and its manufacturing method

The present invention relates to an adhesive film for circuit connection and a method for manufacturing the same, and a connection structure and a method for manufacturing the same.

The method of mounting a liquid crystal drive IC on a liquid crystal display glass panel can be roughly divided into two types: COG (Chip-on-Glass) mounting and COF (Chip-on-Flex) mounting. In COG mounting, the liquid crystal drive IC is directly bonded onto the glass panel using an adhesive containing conductive particles (for example, a circuit connection adhesive). On the other hand, in COF mounting, a liquid crystal driving IC is bonded to a flexible tape having metal wiring, and they are bonded to a glass panel using an adhesive containing conductive particles (for example, an adhesive for circuit connection).

By the way, with the recent increase in the definition of liquid crystal displays, the metal bumps, which are the circuit electrodes of liquid crystal drive ICs, have become narrower in pitch and area. Therefore, the conductive particles in the adhesive may flow out between the adjacent circuit electrodes and cause a short circuit. This tendency is particularly remarkable in COG mounting. When conductive particles flow out between adjacent circuit electrodes, the number of conductive particles captured between the metal bump and the glass panel decreases, and the connection resistance between the opposing circuit electrodes increases, which may cause connection failure.

As a method for solving these problems, a method has been proposed in which a plurality of insulating particles (child particles) are attached to the surface of conductive particles (mother particles) to form composite particles (insulation-coated conductive particles). For example, Patent Document 1 proposes a method of adhering spherical resin particles to the surface of conductive particles.

Japanese Patent No. 4773685

In order to solve the above-mentioned problem without using the insulating coated conductive particles, the present inventors previously placed the conductive particles in the recesses of the substrate on which the recesses were formed, and then formed the recesses of the substrate. We are considering manufacturing an adhesive film for circuit connection by providing an adhesive layer on the surface of the surface and transferring conductive particles to the adhesive layer. According to this method, the conductive particles can be arranged so as to be arranged in a predetermined region in the film in a separated state. Therefore, for example, by manufacturing a circuit connection adhesive film using a substrate having a recess pattern corresponding to the pattern of electrodes to be connected (circuit pattern), the position and number of conductive particles in the circuit connection adhesive film can be obtained. Can be sufficiently controlled.

However, in the above method, in order to transfer the conductive particles to the adhesive layer, it is necessary to give the adhesive layer an appropriate fluidity. Therefore, in the circuit connection adhesive film obtained by the above method, the resin constituting the adhesive layer flows at the time of connection, and at the same time, the conductive particles also flow, so that the conductive particles are excluded from the opposing circuit electrodes. It may end up. It is also conceivable to suppress the flow of the conductive particles by transferring the conductive particles to the adhesive layer and then curing the adhesive layer. In this case, the resin existing between the electrode and the conductive particles at the time of connection is present. It is difficult to eliminate the particles and the connection resistance is likely to increase.

Therefore, according to the present invention, it is possible to improve the capture rate of the conductive particles between the facing circuit electrodes while sufficiently controlling the position and the number of the conductive particles, and to sufficiently secure the continuity between the electrodes. The main purpose is to provide a method for producing an adhesive film for circuit connection that can be used.

One aspect of the present invention relates to a method for manufacturing an adhesive film for circuit connection shown in the following [1] to [18].

[1] To prepare a substrate having a plurality of recesses on the surface and having conductive particles arranged in at least a part of the plurality of recesses, and on the surface of the substrate, a photocurable component and a first first. By providing the composition layer containing a thermosetting component, the conductive particles are transferred to the composition layer, and by irradiating the composition layer with light, a plurality of the conductive particles and the photocurable are obtained. Forming a first adhesive layer containing a cured product of a sex component and the first thermosetting component, and forming a second thermosetting component on one surface of the first adhesive layer. A method for producing an adhesive film for circuit connection, comprising providing a second adhesive layer to be contained.

[2] In [1], the photocurable component contains a radical polymerizable compound and a photoradical polymerization initiator, and the first thermocurable component contains a cationically polymerizable compound and a thermally cationic polymerization initiator. The method for manufacturing an adhesive film for circuit connection described.

[3] The method for producing an adhesive film for circuit connection according to [2], wherein the first thermosetting component contains a compound having a cyclic ether group as the cationically polymerizable compound.

[4] The circuit connection adhesive according to [3], wherein the first thermosetting component contains at least one selected from the group consisting of an oxetane compound and an alicyclic epoxy compound as the cationically polymerizable compound. Method for manufacturing agent film.

[5] The adhesive film for circuit connection according to any one of [2] to [4], wherein the photocurable component contains a compound represented by the following formula (1) as the radically polymerizable compound. Production method.

[In the formula (1), R ¹ represents a hydrogen atom or a methyl group, and X represents an alkanediyl group having 1 to 3 carbon atoms. ]

[6] The adhesive film for circuit connection according to any one of [2] to [5], wherein the photocurable component contains a compound represented by the following formula (I) as the photoradical polymerization initiator. Manufacturing method.

[In formula (I), R ² , R ³ and R ⁴ each independently represent an organic group containing a hydrogen atom, an alkyl group having 1 to 20 carbon atoms or an aromatic hydrocarbon group. ]

[7] The first thermosetting component contains, as the thermal cationic polymerization initiator, a salt compound having a cation represented by the following formula (II) or the following formula (III), [2] to [6]. ]. The method for manufacturing an adhesive film for circuit connection according to any one of.

[In formula (II), R ⁵ and R ⁶ each independently contain a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an organic group containing a substituent or an unsubstituted aromatic hydrocarbon group. Shown, R ⁷ represents an alkyl group having 1 to 6 carbon atoms. ]

[In formula (III), R ⁸ and R ⁹ each independently contain a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an organic group containing a substituent or an unsubstituted aromatic hydrocarbon group. As shown, R ¹⁰ and R ¹¹ each independently represent an alkyl group having 1 to 6 carbon atoms. ]

[8] The average particle size of the conductive particles is 1 to 30 μm, and the particle size of the conductive particles is C.I. V. The method for producing an adhesive film for circuit connection according to any one of [1] to [7], wherein the value is 20% or less.

[9] The method for producing an adhesive film for circuit connection according to any one of [1] to [8], wherein the conductive particles are solder particles.

[10] The method for producing an adhesive film for circuit connection according to [9], wherein the solder particles contain at least one selected from the group consisting of tin, tin alloys, indium and indium alloys.

[11] The solder particles are In—Bi alloy, In—Sn alloy, In—Sn—Ag alloy, Sn—Au alloy, Sn—Bi alloy, Sn—Bi—Ag alloy, Sn—Ag—Cu alloy and Sn. -The method for producing an adhesive film for circuit connection according to [10], which comprises at least one selected from the group consisting of Cu alloys.

[12] The method for producing an adhesive film for circuit connection according to any one of [9] to [11], wherein the solder particles have a flat surface portion on a part of the surface.

[13] The method for producing an adhesive film for circuit connection according to [12], wherein the ratio (B / A) of the diameter B of the flat surface portion to the diameter A of the solder particles satisfies the following formula.
0.01 <B / A <1.0

[14] When a quadrangle circumscribing the projected image of the conductive particles is created by two pairs of parallel lines, and the distances between the opposing sides are X and Y (where Y <X), X and Y are The method for producing an adhesive film for circuit connection according to any one of [1] to [13], which satisfies the following formula.
0.8 <Y / X ≦ 1.0

[15] The method for manufacturing an adhesive film for circuit connection according to any one of [1] to [14], wherein the plurality of recesses are formed in a predetermined pattern.

In the production method of the above aspect, a composition containing a photocurable component and a thermosetting component is used, and the composition is photocured after the conductive particles are transferred to the layer (composition layer) composed of the composition. .. Therefore, it is possible to suppress the resin flow at the time of connection without impairing the transferability. Therefore, according to the manufacturing method of the above-mentioned aspect, it is possible to improve the capture rate of the conductive particles between the facing circuit electrodes while sufficiently controlling the position and the number of the conductive particles in the adhesive film for circuit connection. Adhesive film for use can be obtained. Further, in the manufacturing method of the above-mentioned side surface, it is possible to sufficiently secure the conduction between the electrodes. This is because the photocurable component can be contained in the photocurable layer (first adhesive layer) of the composition layer after the photocuring by using the photocurable component and the thermosetting component in combination. Since it is possible to impart resin fluidity to the layer to the extent that the conductive particles are not excluded at the time of connection, it is difficult to remove the resin existing between the electrode and the conductive particles at the time of connection, which causes a problem that the connection resistance increases. Is presumed to be suppressed.

Another aspect of the present invention relates to the adhesive film for circuit connection shown in the following [16].

[16] An adhesive film for circuit connection containing conductive particles, which comprises a plurality of the conductive particles, a cured product of a photocurable component, and a first adhesive layer containing a first thermosetting component. A second adhesive layer containing a second thermosetting component provided on the first adhesive layer is provided, and at least a part of the plurality of conductive particles is the adhesive film for circuit connection. In the plan view of the above, the adhesive film for circuit connection is arranged in a predetermined pattern, and in the vertical cross section of the adhesive film for circuit connection, adjacent conductive particles are arranged in the horizontal direction while being separated from each other.

Another aspect of the present invention relates to the connection structure shown in the following [17].

[17] The first circuit member having the first electrode, the second circuit member having the second electrode, and the cured body of the adhesive film for circuit connection according to [16]. A connection structure comprising a connection portion for electrically connecting the electrode and the second electrode to each other via the conductive particles and adhering the first circuit member and the second circuit member. ..

Another aspect of the present invention relates to a method for manufacturing a connection structure shown in the following [18].

[18] The surface of the first circuit member having the first electrode on which the first electrode is provided and the second electrode of the second circuit member having the second electrode are provided. A laminate including the circuit connection adhesive film according to [16], the first circuit member, the circuit connection adhesive film, and the second circuit member. Is heated in a state of being pressed in the thickness direction of the laminated body, whereby the first electrode and the second electrode are electrically connected to each other via the conductive particles, and the first circuit member. A method for manufacturing a connection structure, which comprises bonding the second circuit member to the second circuit member.

According to the present invention, it is possible to improve the capture rate of the conductive particles between the facing circuit electrodes while sufficiently controlling the position and the number of the conductive particles, and to sufficiently secure the continuity between the electrodes. It is possible to provide a method for producing an adhesive film for circuit connection.

FIG. 1 is a schematic cross-sectional view showing an embodiment of an adhesive film for circuit connection. FIG. 2 is a schematic plan view showing an example of arrangement of conductive particles in the circuit connection adhesive film of FIG. FIG. 3 is a schematic plan view showing an example of arrangement of conductive particles in the circuit connection adhesive film of FIG. 1. FIG. 4 is a schematic cross-sectional view showing another embodiment of the adhesive film for circuit connection. FIG. 5 is a schematic cross-sectional view of a substrate used for manufacturing the circuit connection adhesive film of FIG. FIG. 6 is a diagram showing a modified example of the cross-sectional shape of the recess of the substrate of FIG. FIG. 7 is a diagram showing a state in which conductive particles are arranged in the recesses of the substrate of FIG. FIG. 8 is a schematic cross-sectional view showing one step of a method for manufacturing an adhesive film for circuit connection according to an embodiment. FIG. 9 is a schematic cross-sectional view showing one step of the method for manufacturing the adhesive film for circuit connection of FIG. FIG. 10 is a schematic cross-sectional view showing one step of the method for manufacturing the adhesive film for circuit connection of FIG. FIG. 11 is a schematic cross-sectional view showing an embodiment of the connection structure. FIG. 12 is a schematic cross-sectional view showing an embodiment of a method for manufacturing a connection structure.

Hereinafter, embodiments of the present invention will be described. However, the present invention is not limited to the following embodiments. Unless otherwise specified, the materials exemplified below may be used alone or in combination of two or more. The content of each component in the composition means the total amount of the plurality of substances present in the composition when a plurality of substances corresponding to each component are present in the composition, unless otherwise specified. The numerical range indicated by using "-" indicates a range including the numerical values before and after "-" as the minimum value and the maximum value, respectively. In the numerical range described stepwise in the present specification, the upper limit value or the lower limit value of the numerical range of one step may be replaced with the upper limit value or the lower limit value of the numerical range of another step. In the numerical range described in the present specification, the upper limit value or the lower limit value of the numerical range may be replaced with the value shown in the examples. As used herein, the term "(meth) acrylate" means at least one of an acrylate and a corresponding methacrylate. The same applies to other similar expressions such as "(meth) acryloyl".

<Adhesive film for circuit connection>
FIG. 1 is a diagram schematically showing a vertical cross section of an adhesive film for circuit connection according to an embodiment. The circuit connection adhesive film 10A shown in FIG. 1 is a first adhesive containing a plurality of conductive particles 4, a cured product of a photocurable component, and an adhesive component 3 containing a first thermosetting component. A film-like adhesive (adhesive film) comprising a layer 1 and a second adhesive layer 2 containing a second thermosetting component provided on the first adhesive layer 1. .. In the present specification, the "longitudinal cross section" means a cross section (cross section in the thickness direction) substantially orthogonal to the main surface (for example, the main surface of the adhesive film 10A for circuit connection). Further, the first thermosetting component and the second thermosetting component mean the thermosetting components contained in the first adhesive layer and the second adhesive layer, respectively.

At least a part of the plurality of conductive particles 4 is arranged in the horizontal direction in a state in which adjacent conductive particles are separated from each other in the vertical cross section of the circuit connection adhesive film 10A. In other words, the circuit connection adhesive film 10A has a central region 10a in which conductive particles 4 in a state of being separated from adjacent conductive particles are arranged in a horizontal direction and conductive particles 4 in the vertical cross section thereof. It is composed of

surface side regions

10b and 10c that do not. Here, the "horizontal direction" means a direction substantially parallel to the main surface of the circuit connection adhesive film (horizontal direction in FIG. 1). It can be confirmed that the adjacent conductive particles are arranged in the horizontal direction in a state of being separated from each other by observing the vertical cross section of the adhesive film for circuit connection with, for example, a scanning electron microscope or the like. In FIG. 1, a part of the conductive particles 4 is exposed from the surface of the first adhesive layer 1 (for example, protruding toward the second adhesive layer 2), but the conductive particles 4 are the first. The entire conductive particles 4 may be embedded in the first adhesive layer 1 so as not to be exposed from the surface of the adhesive layer 1.

2 and 3 are plan views schematically showing an arrangement example of the conductive particles 4 in the circuit connection adhesive film 10A. As shown in FIGS. 2 and 3, at least a part of the plurality of conductive particles 4 are arranged in a predetermined pattern in a plan view of the circuit connection adhesive film. In FIG. 2, in the plan view of the circuit connecting adhesive film, the conductive particles 4 are arranged at regular and substantially even intervals with respect to the entire region of the circuit connecting adhesive film 10A. As shown in 3, in the plan view of the circuit connection adhesive film, a region 10d in which a plurality of conductive particles 4 are regularly arranged and a region 10e in which the conductive particles 4 do not exist are regularly formed. As such, the conductive particles 4 may be arranged. The position and number of the conductive particles 4 can be set, for example, according to the shape, size, pattern, and the like of the electrodes to be connected. The fact that at least a part of the plurality of conductive particles are lined up in a predetermined pattern means that the circuit connection adhesive film is observed from above the main surface of the circuit connection adhesive film using, for example, an electron microscope. Can be confirmed by.

(First adhesive layer)
The first adhesive layer 1 is a cured product of conductive particles 4 (hereinafter, may be referred to as "(A) component") and a photocurable component (hereinafter, may be referred to as "(B) component"). And a first thermosetting component (hereinafter, may be referred to as “(C) component”). The cured product of the component (B) may be a cured product obtained by completely curing the component (B), or may be a cured product obtained by curing a part of the component (B). The component (C) is a component that can flow at the time of connection, and is, for example, an uncured curable component (for example, a resin component). The components other than the conductive particles 4 constituting the first adhesive layer 1 are, for example, non-conductive components (for example, an insulating resin component).

[(A) component: conductive particles]
The component (A) is not particularly limited as long as it is a conductive particle, and is a metal particle made of a metal such as Au, Ag, Pd, Ni, Cu, or solder, or a conductive carbon made of conductive carbon. It may be a particle or the like. The component (A) may be a coated conductive particle containing a nucleus containing non-conductive glass, ceramic, plastic (polystyrene, etc.) and the like, and a coating layer containing the metal or conductive carbon and covering the nucleus. good. As the component (A), one kind of conductive particles can be used alone or two or more kinds of conductive particles can be used in combination.

When coated conductive particles are used as the component (A), the cured product of the thermosetting component can be easily deformed by heating or pressurizing. Therefore, when the electrodes are electrically connected to each other, the electrode and (A) are used. The contact area with the components can be increased, and the conductivity between the electrodes can be further improved.

When metal particles formed of a heat-meltable metal are used as the component (A), the connection between the electrodes tends to be stronger. This tendency is remarkable when solder particles are used as the component (A).

The solder particles may contain at least one selected from the group consisting of tin, tin alloys, indium and indium alloys from the viewpoint of achieving both connection strength and low melting point.

As the tin alloy, for example, In—Sn alloy, In—Sn—Ag alloy, Sn—Au alloy, Sn—Bi alloy, Sn—Bi—Ag alloy, Sn—Ag—Cu alloy, Sn—Cu alloy and the like are used. be able to. Specific examples of these tin alloys include the following examples.
-In-Sn (In 52% by mass, Sn 48% by mass, melting point 118 ° C)
In-Sn-Ag (In 20% by mass, Sn77.2% by mass, Ag 2.8% by mass, melting point 175 ° C.)
-Sn-Bi (Sn43% by mass, Bi57% by mass, melting point 138 ° C.)
-Sn-Bi-Ag (Sn42 mass%, Bi57 mass%, Ag1 mass% melting point 139 ° C.)
-Sn-Ag-Cu (Sn96.5% by mass, Ag3% by mass, Cu0.5% by mass, melting point 217 ° C)
-Sn-Cu (Sn99.3% by mass, Cu0.7% by mass, melting point 227 ° C)
-Sn-Au (Sn21.0% by mass, Au79.0% by mass, melting point 278 ° C.)

As the indium alloy, for example, an In—Bi alloy, an In—Ag alloy, or the like can be used. Specific examples of these indium alloys include the following examples.
-In-Bi (In66.3% by mass, Bi33.7% by mass, melting point 72 ° C.)
-In-Bi (In33.0% by mass, Bi67.0% by mass, melting point 109 ° C)
In-Ag (In97.0% by mass, Ag3.0% by mass, melting point 145 ° C)
The above-mentioned indium alloy containing tin shall be classified as a tin alloy.

The solder particles are In—Bi alloys, In—Sn alloys, In—Sn—Ag alloys, Sn—Au alloys, Sn—Bi alloys from the viewpoint of obtaining higher reliability during high temperature and high humidity tests and thermal shock tests. , Sn-Bi-Ag alloy, Sn-Ag-Cu alloy and Sn-Cu alloy may contain at least one selected from the group.

The tin alloy or indium alloy may be selected according to the intended use (temperature at the time of use) of the solder particles. For example, when solder particles are used for fusion at a low temperature, if an In—Sn alloy or a Sn—Bi alloy is used, the solder particles can be fused at 150 ° C. or lower. When a material having a high melting point such as a Sn—Ag—Cu alloy or a Sn—Cu alloy is used, high reliability can be maintained even after being left at a high temperature.

The solder particles may contain one or more selected from Ag, Cu, Ni, Bi, Zn, Pd, Pb, Au, P and B. When the solder particles contain Ag or Cu, the melting point of the solder particles can be lowered to about 220 ° C., and the bonding strength with the electrode is further improved, so that better conduction reliability can be easily obtained.

The Cu content of the solder particles is, for example, 0.05 to 10% by mass, and may be 0.1 to 5% by mass or 0.2 to 3% by mass. When the Cu content is 0.05% by mass or more, it becomes easy to achieve better solder connection reliability. Further, when the Cu content is 10% by mass or less, the melting point is low and the solder particles tend to have excellent wettability, and as a result, the connection reliability of the joint portion by the solder particles tends to be good.

The Ag content of the solder particles is, for example, 0.05 to 10% by mass, and may be 0.1 to 5% by mass or 0.2 to 3% by mass. When the Ag content is 0.05% by mass or more, it becomes easy to achieve better solder connection reliability. Further, when the Ag content is 10% by mass or less, the solder particles have a low melting point and excellent wettability, and as a result, the connection reliability of the joint portion by the solder particles tends to be good.

The solder particles may have a flat surface on a part of the surface. When such solder particles are used, a wide contact area can be secured between the flat surface portion and the electrode by contacting the flat surface portion of the solder particles with the electrode. Further, when connecting an electrode made of a material in which solder easily wets and spreads and an electrode made of a material in which solder does not easily wet and spread, adjustment is made so that a flat portion of solder particles is arranged on the latter electrode side. By doing so, the connection between the two electrodes can be suitably performed. The surface of the solder particles other than the flat surface portion may be spherical crown-shaped. That is, the solder particles may have a flat surface portion and a spherical crown-shaped curved surface portion. Specifically, the solder particles may have a shape in which a flat surface portion having a diameter B is formed on a part of the surface of a sphere having a diameter A. When such solder particles are used, more excellent conduction reliability and insulation reliability can be easily obtained.

When the solder particles have a shape in which a flat portion having a diameter B is formed on a part of the surface of a sphere having a diameter A, the solder particles have a diameter A with respect to the diameter A from the viewpoint of achieving better conduction reliability and insulation reliability. The ratio (B / A) of the diameter B of the flat surface portion may be, for example, more than 0.01 and less than 1.0 (0.01 <B / A <1.0), and may be 0.1 to 0.9. You may. The diameter A of the solder particles and the diameter B of the flat surface portion can be observed by, for example, a scanning electron microscope or the like. Specifically, arbitrary solder particles are observed with a scanning electron microscope, and an image is taken. From the obtained image, the diameter A of the solder particles and the diameter B of the flat surface portion are measured, and the B / A of the particles is obtained. This operation is performed on 300 solder particles to calculate an average value, which is used as the B / A of the solder particles.

When a quadrangle circumscribing the projected image of conductive particles is created by two pairs of parallel lines, and the distances between the opposite sides are X and Y (where Y <X), respectively, the ratio of Y to X (Y / X). ) May be more than 0.8 and 1.0 or less (0.8 <Y / X ≦ 1.0). Such conductive particles can be said to be particles closer to a true sphere. When the conductive particles have a shape close to a true sphere, the solder particles tend to be easily accommodated in the recesses of the substrate in the manufacturing method described later. Further, when solder particles are used among the conductive particles, the solder particles have a shape close to a true sphere, so that when the solder particles and the electrodes are electrically connected to each other via solder, the solder particles and the electrodes are connected to each other. The contact is less likely to be uneven, and a stable connection tends to be obtained. The ratio of Y to X (Y / X) may be greater than 0.8 and less than 1.0 (0.8 <Y / X <1.0) and may be 0.81 to 0.99. .. The projected image of the conductive particles can be obtained, for example, by observing any conductive particles with a scanning electron microscope. When calculating Y / X, draw two pairs of parallel lines on the obtained projected image, one pair of parallel lines is at the position where the distance between the parallel lines is the minimum, and the other pair of parallel lines is the distance between the parallel lines. Place in the position where is the maximum. This operation is performed on 300 conductive particles to calculate the average value of Y / X, which is used as the Y / X of the conductive particles.

The component (A) may be an insulating coated conductive particle containing the above-mentioned metal particles, conductive carbon particles or coated conductive particles, and an insulating material such as a resin, and having an insulating layer covering the surface of the particles. .. When the component (A) is an insulating coated conductive particle, even when the content of the component (A) is large, the insulating layer is provided on the surface of the particle, so that the component (A) is short-circuited due to contact with each other. The generation can be suppressed, and the insulation between adjacent electrode circuits can be improved.

The average particle size of the component (A) may be 1 μm or more, 2 μm or more, or 4 μm or more from the viewpoint that excellent conductivity can be easily obtained. The average particle size of the component (A) may be 30 μm or less, 25 μm or less, or 20 μm or less from the viewpoint that better connection reliability to a minute-sized electrode can be easily obtained. From these viewpoints, the average particle size of the component (A) may be 1 to 30 μm, 2 to 25 μm, or 4 to 20 μm.

The average particle size of the component (A) can be measured by using various methods according to the size. For example, a dynamic light scattering method, a laser diffraction method, a centrifugal sedimentation method, an electrical detection band method, a resonance type mass measurement method, or the like can be used. Further, a method of measuring the particle size from an image obtained by an optical microscope, an electron microscope, or the like can be used. Specific examples include a flow type particle image analyzer, a microtrack, a Coulter counter, and the like. The particle size of the non-spherical component (A) may be the diameter of a circle circumscribing the conductive particles in the SEM image.

(A) C. of the particle size of the component. V. The value may be 20% or less, 10% or less, 7% or less, or 5% or less from the viewpoint of achieving better conductivity reliability and insulation reliability. (A) C.I. V. The lower limit of the value is not particularly limited, and may be, for example, 0.1% or more, 1% or more, or 2% or more.

(A) C. of the particle size of the component. V. The value is calculated by dividing the standard deviation of the particle size of the conductive particles by the average particle size and multiplying by 100. The standard deviation of the particle size of the conductive particles can be measured by the same method as the above-mentioned method for measuring the average particle size of the conductive particles.

The component (A) has an average particle size of 1 to 30 μm and has a particle size of C.I. V. It may be conductive particles having a value of 20% or less. Such conductive particles have both a small average particle diameter and a narrow particle size distribution, and can be suitably used as conductive particles applied to an anisotropic conductive material having high conductivity reliability and insulation reliability.

The content of the component (A) is, for example, 1% by mass or more, 5% by mass or more, or 10% by mass or more, based on the total mass of the first adhesive layer from the viewpoint of further improving the conductivity. May be. The content of the component (A) may be, for example, 80% by mass or less, 70% by mass or less, or 60% by mass or less based on the total mass of the first adhesive layer from the viewpoint of easily suppressing a short circuit. .. From these viewpoints, the content of the component (A) may be, for example, 1 to 80% by mass, 5 to 70% by mass, or 10 to 60% by mass, based on the total mass of the first adhesive layer. ..

The particle density of the component (A) in the first adhesive layer 1 is 100 / mm ² or more, 1000 / mm ² or more, 3000 / mm ² or more or 5000 from the viewpoint of obtaining stable connection resistance. It may be / mm ² or more. The particle density of the component (A) in the first adhesive layer 1 is 100,000 pieces / mm ² or less, 70,000 pieces / mm ² or less, 50,000 pieces / mm ² or less from the viewpoint of improving the insulating property between adjacent electrodes. Alternatively, it may be 30,000 pieces / mm ² or less.

[(B) component: photocurable component]
The component (B) is not particularly limited as long as it is a component that is cured by light irradiation (for example, a resin component), but may be a component having radical curability from the viewpoint of better connection resistance. The component (B) contains, for example, a radically polymerizable compound (hereinafter, may be referred to as “(B1) component”) and a photoradical polymerization initiator (hereinafter, may be referred to as “(B2) component”). You may be. The component (B) can be a component composed of the component (B1) and the component (B2).

Component (B1): Radical polymerizable compound The component (B1) is a compound (radical polymerizable compound) having a polymerizable group (radical polymerizable group) that reacts with a radical. Examples of the radically polymerizable group include a (meth) acryloyl group, a vinyl group, an allyl group, a styryl group, an alkenyl group, an alkenylene group, a maleimide group and the like. The number of radically polymerizable groups (number of functional groups) of the component (B1) is 2 or more from the viewpoint that the desired melt viscosity can be easily obtained after polymerization, the effect of reducing the connection resistance is further improved, and the connection reliability is superior. It may be 10 or less from the viewpoint of suppressing curing shrinkage during polymerization. Further, in order to balance the crosslink density and the curing shrinkage, in addition to the compound having the number of radically polymerizable groups within the above range, a compound having the number of radically polymerizable groups outside the above range may be used. good.

The component (B1) may contain, for example, a polyfunctional (bifunctional or higher) (meth) acrylate from the viewpoint of suppressing the flow of conductive particles. The polyfunctional (bifunctional or higher) (meth) acrylate may be a bifunctional (meth) acrylate, and the bifunctional (meth) acrylate may be a bifunctional aromatic (meth) acrylate.

Examples of the polyfunctional (meth) acrylate include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, and polyethylene glycol di (meth) acrylate. ) Acrylate, propylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, tetrapropylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, ethoxylated polypropylene glycol Di (meth) acrylate, 1,3-butanediol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, neopentylglycoldi (meth) acrylate, 3-methyl-1,5-pentanediol di (Meta) acrylate, 1,6-hexanediol di (meth) acrylate, 2-butyl-2-ethyl-1,3-propanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, 1 , 10-decanediol di (meth) acrylate, glycerindi (meth) acrylate, tricyclodecanedimethanol (meth) acrylate, 2-methyl-1,3-propanediol di (meth) acrylate ethoxylated, trimethylolpropane tri (Meta) acrylate, ethoxylated trimethylolpropane tri (meth) acrylate, propoxylated trimethylolpropane tri (meth) acrylate, ethoxylated trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, ethoxylated Pentaerythritol tri (meth) acrylate, propoxylated pentaerythritol tri (meth) acrylate, ethoxylated propoxylated pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, ethoxylated pentaerythritol tetra (meth) acrylate, propoxydated Fat group (meth) acrylates such as pentaerythritol tetra (meth) acrylate, ethoxylated propoxylated pentaerythritol tetra (meth) acrylate, ditrimethylolpropane tetraacrylate, dipentaerythritol hexa (meth) acrylate; ethoxylated bisphenol A type di ( Meta) Acrylate Relate, propoxylated bisphenol A type di (meth) acrylate, ethoxylated propoxylated bisphenol A type di (meth) acrylate, ethoxylated bisphenol F type di (meth) acrylate, propoxylated bisphenol F type di (meth) acrylate, ethoxylated Propoxylated bisphenol F-type di (meth) acrylate, ethoxylated fluorene-type di (meth) acrylate (eg, 9,9-bi [4- (2-acryloyloxyethoxy) phenyl] fluorene), propoxylated fluorene-type di (meth). ) Aromatic (meth) acrylates such as acrylates and ethoxylated propoxylated fluorene-type di (meth) acrylates; Aromatic epoxy (meth) acrylates; examples include isocyanurate (meth) acrylates such as caprolactone-modified tris- (2-acryloxyethyl) isocyanurate.

The content of the polyfunctional (bifunctional or higher) (meth) acrylate is, for example, 40 to 100, based on the total mass of the component (B1), from the viewpoint of achieving both the effect of reducing the connection resistance and the suppression of particle flow. It may be% by mass, 50 to 100% by mass, or 60 to 100% by mass.

The component (B1) may further contain a monofunctional (meth) acrylate in addition to the polyfunctional (bifunctional or higher) (meth) acrylate. Examples of the monofunctional (meth) acrylate include (meth) acrylic acid; methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, and tert-butyl (meth) acrylate. Butoxyethyl (meth) acrylate, isoamyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, heptyl (meth) acrylate, octylheptyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) Acrylate 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-chloro-2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, ethoxy Acrylate (meth) acrylates such as polyethylene glycol (meth) acrylates, methoxypolypropylene glycol (meth) acrylates, ethoxypolypropylene glycol (meth) acrylates, and mono (2- (meth) acryloyloxyethyl) succinates; benzyl (meth) acrylates. , Phenyl (meth) acrylate, o-biphenyl (meth) acrylate, 1-naphthyl (meth) acrylate, 2-naphthyl (meth) acrylate, phenoxyethyl (meth) acrylate, p-cumylphenoxyethyl (meth) acrylate, o -Phenylphenoxyethyl (meth) acrylate, 1-naphthoxyethyl (meth) acrylate, 2-naphthoxyethyl (meth) acrylate, phenoxypolyethylene glycol (meth) acrylate, nonylphenoxypolyethylene glycol (meth) acrylate, phenoxypolypropylene glycol (meth) acrylate, 2-Hydroxy-3-phenoxypropyl (meth) acrylate, 2-hydroxy-3- (o-phenylphenoxy) propyl (meth) acrylate, 2-hydroxy-3- (1-naphthoxy) propyl (meth) acrylate, 2- Aromatic (meth) acrylates such as hydroxy-3- (2-naphthoxy) propyl (meth) acrylates and bisphenol A type epoxy (meth) acrylates; (meth) acrylates having epoxy groups such as glycidyl (meth) acrylates, 3, 4-Epoxycyclohexylmethyl (meth) acrylate, etc. Examples thereof include (meth) acrylate having an alicyclic epoxy group, (meth) acrylate having an oxetanyl group such as (3-ethyloxetane-3-yl) methyl (meth) acrylate, and the like.

The content of the monofunctional (meth) acrylate may be, for example, 0 to 60% by mass, 0 to 50% by mass, or 0 to 40% by mass based on the total mass of the component (B1).

The cured product of the component (B) may have, for example, a polymerizable group that reacts with a substance other than a radical. The polymerizable group that reacts with a non-radical substance may be, for example, a cationically polymerizable group that reacts with a cation. Examples of the cationically polymerizable group include an epoxy group such as a glycidyl group, an alicyclic epoxy group such as an epoxycyclohexylmethyl group, and an oxetanyl group such as an ethyloxetanylmethyl group. The cured product of the component (B) having a polymerizable group that reacts by other than radicals is, for example, a (meth) acrylate having an epoxy group, a (meth) acrylate having an alicyclic epoxy group, and a (meth) acrylate having an oxetanyl group. It can be introduced by using a (meth) acrylate having a polymerizable group that reacts with a non-radical substance such as (B) as a component (B).

The (meth) acrylate having a polymerizable group that reacts with a substance other than a radical is represented by the following formula (1) from the viewpoint of cross-linking a radically polymerizable compound with a thermosetting component described later to form a stronger connection portion at the time of connection. ) May be used.

In the formula (1), R ¹ represents a hydrogen atom or a methyl group, and X represents an alkanediyl group having 1 to 3 carbon atoms. Examples of the alkanediyl group having 1 to 3 carbon atoms include a methylene group, an ethylene group and a propylene group. Specific examples of the compound represented by the above formula (1) include 3,4-epoxycyclohexylmethyl (meth) acrylate.

A radically polymerizable compound having a polymerizable group that reacts with a non-radical substance (for example, (meth) acrylate) is a radically polymerizable compound having no polymerizable group that reacts with a non-radical substance from the viewpoint of suppressing curing shrinkage during polymerization. For example, it may be used in combination with (meth) acrylate). (B1) Mass ratio of radically polymerizable compound having a polymerizable group that reacts with other than radicals to the total mass of the component (mass (charged amount) of radically polymerizable compound having a polymerizable group that reacts with other than radicals) / (B1) From the viewpoint of improving reliability, the total mass (charged amount) of the components may be, for example, 0 or more, 0.1 or more, 0.2 or more, or 0.3 or more, and 0.7 or less, 0.6. Hereinafter, it may be 0.5 or less or 0.4 or less, and may be 0 to 0.7, 0.1 to 0.6, 0.2 to 0.5 or 0.3 to 0.4. From the viewpoint of further suppressing the curing shrinkage during polymerization, the mass ratio of the (meth) acrylate having a polymerizable group reacting with other than radicals to the (meth) acrylate having no polymerizable group reacting with other than radicals is in the above range. There may be.

The component (B1) may contain other radically polymerizable compounds in addition to polyfunctional (bifunctional or higher) and monofunctional (meth) acrylates. Examples of other radically polymerizable compounds include maleimide compounds, vinyl ether compounds, allyl compounds, styrene derivatives, acrylamide derivatives, nadiimide derivatives and the like. The content of the other radically polymerizable compound may be, for example, 0 to 40% by mass based on the total mass of the component (B1).

Component (B2): Photoradical Polymerization Initiator The component (B2) comprises light containing a wavelength in the range of 150 to 750 nm, preferably light containing a wavelength in the range of 254 to 405 nm, and more preferably a wavelength in the range of 365 nm. It is a photopolymerization initiator (photolatent radical radical generator) that generates a radical by irradiation with light (for example, ultraviolet light). As the component (B2), one type may be used alone, or a plurality of them may be used in combination.

The component (B2) is decomposed by light to generate free radicals. That is, the component (B2) is a compound that generates radicals by applying light energy from the outside. The component (B2) includes an oxime ester structure, a bisimidazole structure, an acrydin structure, an α-aminoalkylphenone structure, an aminobenzophenone structure, an N-phenylglycine structure, an acylphosphine oxide structure, a benzyldimethylketal structure, and an α-hydroxyalkylphenone structure. It may be a compound having a structure such as. As the component (B2), one type may be used alone, or a plurality of them may be used in combination.

The component (B2) has an oxime ester structure from the viewpoint of further suppressing the flow of conductive particles and further improving the capture rate, and further suppressing peeling after connection and further suppressing an increase in connection resistance. It may be a compound. From the same viewpoint, the compound having an oxime ester structure may be a compound represented by the following formula (I).

In formula (I), R ² , R ³ and R ⁴ each independently represent an organic group containing a hydrogen atom, an alkyl group having 1 to 20 carbon atoms or an aromatic hydrocarbon group.

Specific examples of the compound having an oxime ester structure include 1-phenyl-1,2-butandion-2- (o-methoxycarbonyl) oxime and 1-phenyl-1,2-propanedione-2- (o-methoxycarbonyl). ) Oxime, 1-phenyl-1,2-propanedione-2- (o-ethoxycarbonyl) oxime, 1-phenyl-1,2-propanedione-2-o-benzoyloxime, 1,3-diphenylpropantrione- 2- (o-ethoxycarbonyl) oxime, 1-phenyl-3-ethoxypropanetrione-2- (o-benzoyl) oxime, 1,2-octanedione, 1- [4- (phenylthio) phenyl-, 2-( o-benzoyloxime)], etanone, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazole-3-yl]-, 1- (o-acetyloxime) and the like. When such a highly active oxime ester-based photoradical polymerization initiator is used, cross-linking can be sufficiently promoted even when the blending amount of the component (B1) is small.

The content of the component (B2) is, for example, 0.1 to 10 parts by mass, 0.3 to 7 parts by mass, or 0.5 with respect to 100 parts by mass of the component (B1) from the viewpoint of suppressing the flow of conductive particles. It may be up to 5 parts by mass.

The content of the cured product of the component (B) is, for example, 1 with respect to 100 parts by mass of the total amount of the components other than the component (A) in the first adhesive layer from the viewpoint of suppressing the flow of the conductive particles. It may be 5 parts by mass or more or 10 parts by mass or more. The content of the cured product of the component (B) is, for example, with respect to 100 parts by mass of the total amount of the components other than the component (A) in the first adhesive layer from the viewpoint of developing low resistance in low-pressure mounting. It may be 30 parts by mass or less, 25 parts by mass or less, or 20 parts by mass or less. From these viewpoints, the content of the cured product of the component (B) is, for example, 1 to 30 parts by mass with respect to 100 parts by mass of the total amount of the components other than the component (A) in the first adhesive layer. It may be 5 to 25 parts by mass or 10 to 20 parts by mass. The content of the component (B) in the composition or the composition layer for forming the first adhesive layer (based on the total mass of the composition or the composition layer) may be the same as the above range.

[(C) component: thermosetting component]
The component (C) is not particularly limited as long as it is a component that cures by heat (for example, a resin component), but if the component (B) is a component having radical curability, the component (C) is (C) from the viewpoint of storage stability and the like. The component may be a component having no radical curability. When the component (B) is a component having radical curability and the component (C) is also a component having radical curability, the thermosetting component is composed of radicals remaining in the first adhesive layer during storage. Curing may proceed. Examples of the non-radical curable component include a cationically curable component (for example, a cationically polymerizable compound and a thermally cationic polymerization initiator) and a component having an anionic curable property (anionic polymerizable compound and a thermally anionic polymerization initiator). Can be mentioned.

The component (C) may be a cationically curable component from the viewpoint of being superior in connection resistance, and for example, a cationically polymerizable compound (hereinafter, may be referred to as “(C1) component”) and thermal cationic polymerization initiation. It may contain an agent (hereinafter, may be referred to as "(C2) component"). The component (C) can be a component consisting only of the component (C1) and the component (C2).

Component (C1): Cationicly polymerizable compound The component (C1) is a compound that crosslinks by reacting with the component (C2) by heat. The component (C1) means a compound having no radically polymerizable group, and the component (C1) is not included in the component (B1). The component (C1) may be used alone or in combination of two or more.

The component (C1) may be a compound having a cyclic ether group from the viewpoint of further improving the effect of reducing the connection resistance and improving the connection reliability. When at least one compound selected from the group consisting of an oxetane compound and an alicyclic epoxy compound is used among the compounds having a cyclic ether group, the effect of reducing the connection resistance tends to be further improved. The component (C1) may contain both at least one oxetane compound and at least one alicyclic epoxy compound from the viewpoint that the desired melt viscosity can be easily obtained.

The oxetane compound as the component (C1) can be used without particular limitation as long as it is a compound having an oxetane group and no radically polymerizable group. Examples of commercially available oxetane compounds include ETERNACOLL OXBP (trade name, 4,4'-bis [(3-ethyl-3-oxetanyl) methoxymethyl] biphenyl, manufactured by Ube Kosan Co., Ltd.), OXSQ, OXT-121, and the like. Examples thereof include OXT-221, OXT-101, and OXT-212 (trade name, manufactured by Toagosei Co., Ltd.). These may use one kind of compound alone or may use a plurality of compounds in combination.

The alicyclic epoxy compound as the component (C1) can be used without particular limitation as long as it is a compound having an alicyclic epoxy group (for example, an epoxycyclohexyl group) and no radical polymerizable group. Commercially available alicyclic epoxy compounds include seroxide 8010 (trade name, B-7-oxavicyclo [4.1.0] heptane, manufactured by Daicel Corporation), for example, EHPE3150, EHPE3150CE, seroxide 2021P, and seroxide. 2081 (trade name, manufactured by Daicel Corporation) and the like can be mentioned. These may use one kind of compound alone or may use a plurality of compounds in combination. As the component (C1), an epoxy compound having an aromatic hydrocarbon group such as a bisphenol A type epoxy resin or a bisphenol F type epoxy resin (for example, trade names "jER1010" and "YL983U" manufactured by Mitsubishi Chemical Corporation). Can also be used. The epoxy compound having an aromatic hydrocarbon group may be used in combination with the alicyclic epoxy compound from the viewpoint of further improving the effect of reducing the connection resistance and improving the connection reliability.

Component (C2): Thermal cation polymerization initiator The component (C2) is a thermal polymerization initiator (thermal latent cation generator) that initiates polymerization by generating an acid or the like by heating. The component (C2) may be a salt compound composed of a cation and an anion. The component (C2) is, for example, BF _4- ^, BR _4- ⁽ R indicates a phenyl group substituted with two or more fluorine atoms or two or more trifluoromethyl groups) ^, PF _6- ^, SbF _6- . , AsF ₆ ^{− and} the like, sulfonium salt, phosphonium salt, ammonium salt, diazonium salt, iodonium salt, anilinium salt, onium salt such as pyridinium salt and the like. These may be used individually by 1 type, and may be used in combination of a plurality of types.

The component (C2) may be, for example, a salt compound having an anion containing boron as a constituent element from the viewpoint of quick curing. Examples of such a salt compound include salt compounds having BF _4- ^or BR _4- ⁽ R indicates a phenyl group substituted with two or more fluorine atoms or two or more trifluoromethyl groups). Be done. The anion containing boron as a constituent element may be BR _4- ^, and more specifically, tetrakis (pentafluorophenyl) borate.

The component (C2) may be a salt compound having a cation represented by the following formula (II) or the following formula (III) from the viewpoint of storage stability.

In formula (II), R ⁵ and R ⁶ each independently represent an organic group containing a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an aromatic hydrocarbon group having or not substituted. , R ⁷ represent an alkyl group having 1 to 6 carbon atoms.

The salt compound having a cation represented by the formula (II) may be an aromatic sulfonium salt compound (aromatic sulfonium salt type thermoacid generator) from the viewpoint of achieving both storage stability and low temperature activity. That is, at ^least one of R5 and R6 in the ^formula (II) may be an organic group having a substituent or containing an unsubstituted aromatic hydrocarbon group. The anion in the salt compound having a cation represented by the formula (II) may be an anion containing antimony as a constituent element, and may be, for example, hexafluoroantimonate (hexafluoroantimonic acid).

Specific examples of the compound having a cation represented by the formula (II) include 1-naphthylmethyl-p-hydroxyphenylsulfonium hexafluoroantimonate (manufactured by Sanshin Chemical Co., Ltd., SI-60 main agent) and the like.

In formula (III), R ⁸ and R ⁹ each independently represent an organic group containing a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an aromatic hydrocarbon group having or not substituted. , R ¹⁰ and R ¹¹ each independently represent an alkyl group having 1 to 6 carbon atoms.

The salt compound having a cation represented by the formula (III) (quaternary ammonium salt type thermoacid generator) is, for example, an anilinium salt compound because it has resistance to a substance that can cause curing inhibition to cation curing. It's okay. That is, at least one of R ⁸ and R ⁹ in the formula (III) may be an organic group having a substituent or containing an unsubstituted aromatic hydrocarbon group. Examples of the anilinium salt compound include N, N-dialkylanilinium salts such as N, N-dimethylanilinium salt and N, N-diethylanilinium salt. The anion in the salt compound having a cation represented by the formula (III) may be an anion containing boron as a constituent element, and may be, for example, tetrakis (pentafluorophenyl) borate.

The compound having a cation represented by the formula (III) may be an anilinium salt having an anion containing boron as a constituent element. Examples of commercially available products of such salt compounds include CXC-1821 (trade name, manufactured by King Industries) and the like.

The content of the component (C2) is, for example, 0. It may be 1 to 20 parts by mass, 1 to 18 parts by mass, 3 to 15 parts by mass, or 5 to 12 parts by mass.

The content of the component (C) is the total amount of the components other than the component (A) in the first adhesive layer from the viewpoint of ensuring the curability of the adhesive film for forming the first adhesive layer. It may be, for example, 5 parts by mass or more, 10 parts by mass or more, 15 parts by mass or more, or 20 parts by mass or more with respect to 100 parts by mass. The content of the component (C) is the total amount of the components other than the component (A) in the first adhesive layer from the viewpoint of ensuring the formability of the adhesive film for forming the first adhesive layer. For example, it may be 70 parts by mass or less, 60 parts by mass or less, 50 parts by mass or less, or 40 parts by mass or less with respect to 100 parts by mass. From these viewpoints, the content of the component (C) is, for example, 5 to 70 parts by mass and 10 to 60 parts by mass with respect to 100 parts by mass of the total amount of the components other than the component (A) in the first adhesive layer. It may be parts by mass, 15 to 50 parts by mass, or 20 to 40 parts by mass. The content of the component (C) in the composition or the composition layer (based on the total mass of the composition or the composition layer) may be the same as the above range.

[Other ingredients]
The first adhesive layer 1 may further contain other components in addition to the component (A), the cured product of the component (B), and the component (C). Examples of other components include a thermoplastic resin (hereinafter, may be referred to as “(D) component”), a coupling agent (hereinafter, may be referred to as “(E) component”), and a filler. (Hereinafter, it may be referred to as "(F) component".) And the like.

Examples of the component (D) include phenoxy resin, polyester resin, polyamide resin, polyurethane resin, polyester urethane resin, acrylic rubber, epoxy resin (solid at 25 ° C.) and the like. These may be used individually by 1 type, and may be used in combination of a plurality of types. By further containing the component (D) in the composition containing the component (B) and the component (C), the composition layer (further, the first adhesive layer 1) can be easily formed from the composition. Can be done. Examples of the phenoxy resin include a fluorene type phenoxy resin, a bisphenol A / bisphenol F copolymer type phenoxy resin, and the like.

The weight average molecular weight (Mw) of the component (D) may be, for example, 5000 to 200,000, 10000 to 100,000, 20000 to 80000 or 40,000 to 60000 from the viewpoint of resin exclusion during mounting. In addition, Mw means a value measured by gel permeation chromatography (GPC) and converted using the calibration curve by standard polystyrene.

The content of the component (D) is, for example, 1 part by mass or more, 5 parts by mass or more, and 10 parts by mass or more with respect to 100 parts by mass of the total amount of the components other than the component (A) in the first adhesive layer. Alternatively, it may be 20 parts by mass or more, 70 parts by mass or less, 60 parts by mass or less, 50 parts by mass or less, or 40 parts by mass or less, and may be 1 to 70 parts by mass, 5 to 60 parts by mass, or 10 to 50 parts by mass. It may be parts or 20 to 40 parts by mass. The content of the component (D) in the composition or the composition layer for forming the first adhesive layer (based on the total mass of the composition or the composition layer) may be the same as the above range.

Examples of the component (E) include a silane coupling agent having an organic functional group such as a (meth) acryloyl group, a mercapto group, an amino group, an imidazole group, and an epoxy group (γ-glycidoxypropyltrimethoxysilane, etc.). Examples thereof include a silane compound such as tetraalkoxysilane, a tetraalkoxy titanate derivative, and a polydialkyl titanate derivative. These may be used individually by 1 type, and may be used in combination of a plurality of types. When the first adhesive layer 1 contains the component (E), the adhesiveness can be further improved. The component (E) may be, for example, a silane coupling agent.

The content of the component (E) may be, for example, 0.1 to 10 parts by mass with respect to 100 parts by mass of the total amount of the components other than the component (A) in the first adhesive layer. The content of the component (E) in the composition or the composition layer for forming the first adhesive layer (based on the total mass of the composition or the composition layer) may be the same as the above range.

Examples of the component (F) include non-conductive fillers (for example, non-conductive particles). The component (F) may be either an inorganic filler or an organic filler. Examples of the inorganic filler include metal oxide fine particles such as silica fine particles, alumina fine particles, silica-alumina fine particles, titania fine particles, and zirconia fine particles; and inorganic fine particles such as metal nitride fine particles. Examples of the organic filler include organic fine particles such as silicone fine particles, methacrylate / butadiene / styrene fine particles, acrylic / silicone fine particles, polyamide fine particles, and polyimide fine particles. These may be used individually by 1 type, and may be used in combination of a plurality of types. The component (F) may be, for example, silica fine particles. The content of the component (F) may be, for example, 0.1 to 10 parts by mass with respect to 100 parts by mass of the total amount of the components other than the component (A) in the first adhesive layer. The content of the component (F) in the composition or the composition layer for forming the first adhesive layer (based on the total mass of the composition or the composition layer) may be the same as the above range.

The first adhesive layer 1 may further contain other additives such as a softener, an accelerator, a deterioration inhibitor, a colorant, a flame retardant, and a thixotropic agent as other components. The content of the other additives may be, for example, 0.1 to 10 parts by mass with respect to 100 parts by mass of the total amount of the components other than the component (A) in the first adhesive layer. The content of the composition for forming the first adhesive layer or other additives in the composition layer (based on the total mass of the composition or the composition layer) may be the same as the above range.

The thickness d1 of the first adhesive layer 1 is, for example, 0.5 μm or more, 1.0 μm or more, or 2.0 μm or more from the viewpoint of transferability of the conductive particles 4 at the time of manufacturing the adhesive film for circuit connection. It may be there. The thickness d1 of the first adhesive layer 1 is, for example, 5.0 μm or less, 4.0 μm or less, or 3.0 μm or less from the viewpoint of being able to capture conductive particles more efficiently at the time of connection. good. From these viewpoints, the thickness d1 of the first adhesive layer 1 may be, for example, 0.5 to 5.0 μm, 1.0 to 4.0 μm, or 2.0 to 3.0 μm. As shown in FIG. 1, when a part of the conductive particles 4 is exposed from the surface of the first adhesive layer 1 (for example, protruding toward the second adhesive layer 2), the first The first adhesive layer 1 and the second adhesive layer 2 located at the separated portions of the adjacent

conductive particles

4 and 4 from the surface 1a of the adhesive layer 1 opposite to the second adhesive layer 2 side. The distance to the boundary S with and (the distance indicated by d1 in FIG. 1) is the thickness of the first adhesive layer 1, and the exposed portion of the conductive particles 4 is included in the thickness of the first adhesive layer 1. I can't.

The thickness d1 of the first adhesive layer 1 is, for example, a bisphenol A type epoxy resin (trade name: jER811, manufactured by Mitsubishi Chemical Co., Ltd.) in which an adhesive film is sandwiched between two sheets of glass (thickness: about 1 mm). After casting with a resin composition consisting of 100 g and 10 g of a curing agent (trade name: Epomount curing agent, manufactured by Refine Tech Co., Ltd.), the cross section is polished using a polishing machine, and a scanning electron microscope (SEM, product) is used. Name: SE-8020, manufactured by Hitachi High-Tech Science Co., Ltd.) can be used for measurement.

<Second adhesive layer>
The second adhesive layer 2 is, for example, an insulating adhesive layer composed of a component having no conductivity (insulating resin component). The second adhesive layer 2 contains at least the component (C).

Details (types, combinations, etc.) of the components (for example, (C1) component, (C2) component, etc.) contained in the (C) component (that is, the second thermosetting component) in the second adhesive layer 2 are , Since the details of the component contained in the component (C) (that is, the first thermosetting component) in the first adhesive layer 1 are the same, detailed description thereof will be omitted here. The second thermosetting component may be the same as or different from the first thermosetting component.

The content of the component (C) is, for example, 5% by mass or more, 10% by mass or more, 15% by mass or more, or 20% by mass, based on the total mass of the second adhesive layer from the viewpoint of maintaining reliability. That may be the above. The content of the component (C) is, for example, 70% by mass or less, 60% by mass, based on the total mass of the second adhesive layer, from the viewpoint of preventing the resin seepage defect in the reel, which is one aspect of the supply form. % Or less, 50% by mass or less, or 40% by mass or less. From these viewpoints, the content of the component (C) is, for example, 5 to 70% by mass, 10 to 15% by mass, 15 to 50% by mass, or 20 to 40, based on the total mass of the second adhesive layer. It may be% by mass.

The second adhesive layer 2 may further contain other components ((D) component, (E) component, (F) component, other additives, etc.) in the first adhesive layer 1. .. Preferred embodiments of the other components are the same as the preferred embodiments of the first adhesive layer 1.

The content of the component (D) may be, for example, 1% by mass or more, 5% by mass or more, or 10% by mass or more, and 80% by mass or less, 60% by mass, based on the total mass of the second adhesive layer. % Or less or 40% by mass or less, and may be 1 to 80% by mass, 5 to 60% by mass, or 10 to 40% by mass.

The content of the component (E) may be, for example, 0.1 to 10% by mass based on the total mass of the second adhesive layer.

The content of the component (F) may be, for example, 1% by mass or more, 10% by mass or more, or 30% by mass or more, and 90% by mass or less, 70% by mass, based on the total mass of the second adhesive layer. % Or less or 50% by mass or less, and may be 1 to 90% by mass or less, 10 to 70% by mass or less, or 30 to 50% by mass.

The content of the other additives may be, for example, 0.1 to 10% by mass based on the total mass of the second adhesive layer.

The thickness d2 of the second adhesive layer 2 may be appropriately set according to the height of the electrodes of the circuit member to be connected and the like. The thickness d2 of the second adhesive layer 2 can sufficiently fill the space between the electrodes to seal the electrodes, and from the viewpoint of obtaining better connection reliability, for example, 2 μm or more and 5 μm. It may be more than or equal to 10 μm, may be 30 μm or less, 20 μm or less, or 15 μm or less, and may be 2 to 30 μm, 5 to 20 μm, or 10 to 15 μm. As shown in FIG. 1, when a part of the conductive particles 4 is exposed from the surface of the first adhesive layer 1 (for example, protruding toward the second adhesive layer 2), the second adhesive layer 2 is exposed. The first adhesive layer 1 and the second adhesive layer 2 located at the separated portions of the adjacent

conductive particles

4 and 4 from the surface 2a of the adhesive layer 2 opposite to the first adhesive layer 1 side. The distance to the boundary S with and (the distance indicated by d2 in FIG. 1) is the thickness of the second adhesive layer 2. The thickness d2 of the second adhesive layer 2 can be obtained, for example, in the same manner as the method for measuring the thickness d1 of the first adhesive layer 1 described above.

The thickness of the circuit connection adhesive film 10A (the total thickness of all the layers constituting the circuit connection adhesive film 10A) may be, for example, 2.5 μm or more, 6 μm or more, or 12 μm or more, and may be 35 μm. Hereinafter, it may be 24 μm or less or 18 μm or less, and may be 2.5 to 35 μm, 6 to 24 μm, or 12 to 24 μm.

The circuit connection adhesive film 10A is an adhesive film used for circuit connection. The circuit connection adhesive film 10A may or may not have anisotropic conductivity. That is, the adhesive film for circuit connection may be an anisotropically conductive adhesive film or a non-anisotropically conductive (for example, isotropically conductive) adhesive film. The circuit connection adhesive film 10A is formed on the surface of the first circuit member having the first electrode on which the first electrode is provided and the second circuit member of the second circuit member having the second electrode. A state in which the laminate including the first circuit member, the circuit connection adhesive film 10A, and the second circuit member is pressed between the surfaces provided with the electrodes in the thickness direction of the laminate. By heating, the first electrode and the second electrode are electrically connected to each other via conductive particles (or molten solidified of conductive particles), and the first circuit member and the second circuit member are connected to each other. It may be used for bonding. The above-mentioned "anisotropic conductivity" means that the material conducts in the pressurized direction and maintains the insulating property in the non-pressurized direction.

According to the circuit connection adhesive film 10A, the thermosetting component ensures the removal of the resin at the time of connection, while the cured product of the photocurable component suppresses the fluidity of the conductive particles at the time of connection and is connected. It is possible to improve the capture rate of conductive particles between the electrodes. Therefore, according to the circuit connection adhesive film 10A, it is possible to obtain a connection structure in which short circuits are less likely to occur and the conductivity between the electrodes is also excellent.

Although the circuit connection adhesive film of one embodiment has been described above, the present invention is not limited to the above embodiment.

The circuit connection adhesive film has a component (C) on the opposite side of the first adhesive layer 1 from the second adhesive layer 2, as in the circuit connection adhesive film 10B shown in FIG. 4, for example. A third adhesive layer 5 containing (thermosetting component) may be provided. The third adhesive layer 5 is, for example, an insulating adhesive layer composed of a component having no conductivity (insulating resin component). The circuit connection adhesive film 10B has the same configuration as the circuit connection adhesive film 10A except that the third adhesive layer 5 is laminated.

The details of the component (C) contained in the third adhesive layer 5 (hereinafter, also referred to as “third thermosetting component”) are the same as those described above. For example, the third thermosetting component may contain a component (C1) (ie, a cationically polymerizable compound) and a component (C2) (ie, a thermally cationic polymerization initiator). Since the (C1) component and the (C2) component used in the third thermosetting component are the same as the (C1) component and the (C2) component used in the first thermosetting component, here. Then, detailed explanation is omitted. The third thermosetting component may be the same as or different from the first thermosetting component. The third thermosetting component may be the same as or different from the second thermosetting component.

The content of the component (C) is, for example, 5% by mass or more, 10% by mass or more, and 15% by mass based on the total mass of the third adhesive layer from the viewpoint of imparting good transferability and peeling resistance. % Or more or 20% by mass or more. The content of the component (C) is, for example, 70% by mass based on the total mass of the third adhesive layer from the viewpoint of imparting good half-cut property and blocking resistance (suppression of resin seepage of the reel). Hereinafter, it may be 60% by mass or less, 50% by mass or less, or 40% by mass or less. From these viewpoints, the content of the component (C) is, for example, 5 to 70% by mass, 10 to 60% by mass, 15 to 50% by mass, or 20 to 40, based on the total mass of the third adhesive layer. It may be% by mass.

The third adhesive layer 5 may further contain other components in the first adhesive layer 1. Preferred embodiments of the other components are the same as the preferred embodiments of the first adhesive layer 1.

The content of the component (D) may be, for example, 10% by mass or more, 20% by mass or more, or 30% by mass or more, and 80% by mass or less, 70% by mass, based on the total mass of the third adhesive layer. It may be% or less or 60% by mass or less, and may be 10 to 80% by mass, 20 to 70% by mass or 30 to 60% by mass.

The content of the component (E) may be, for example, 0.1 to 10% by mass based on the total mass of the third adhesive layer.

The content of the component (F) may be, for example, 1% by mass or more, 3% by mass or more, or 5% by mass or more, and 50% by mass or less, 40% by mass, based on the total mass of the third adhesive layer. % Or less or 30% by mass or less, and may be 1 to 50% by mass, 3 to 40% by mass, or 5 to 30% by mass.

The content of the other additives may be, for example, 0.1 to 10% by mass based on the total mass of the third adhesive layer.

The thickness d3 of the third adhesive layer 5 may be appropriately set according to the height of the electrodes of the circuit member to be adhered. The thickness d3 of the third adhesive layer 5 can sufficiently fill the space between the electrodes to seal the electrodes, and from the viewpoint of obtaining better connection reliability, for example, 0.1 μm or more. , 0.5 μm or more or 1.0 μm or more, 10 μm or less, 5.0 μm or less or 2.5 μm or less, 0.1 to 10 μm, 0.5 to 5.0 μm or 1.0 to It may be 2.5 μm. The thickness d3 of the third adhesive layer 5 is the second adhesion in the first adhesive layer 1 from the surface 5a of the third adhesive layer 5 opposite to the side of the first adhesive layer 1. It is a distance to the surface 1a on the side opposite to the agent layer 2 side (distance indicated by d3 in FIG. 4), and is obtained, for example, in the same manner as the above-mentioned method for measuring the thickness d1 of the first adhesive layer 1. Can be done.

When the circuit connection adhesive film has a layer other than the first adhesive layer and the second adhesive layer (for example, a third adhesive layer), the thickness of the circuit connection adhesive film (for circuit connection). The total thickness of all the layers constituting the adhesive film) may be the same as the thickness of the circuit connection adhesive film 10A described above can be taken.

<Manufacturing method of adhesive film for circuit connection>
The method for manufacturing an adhesive film for circuit connection is to prepare a substrate having a plurality of recesses on the surface and having conductive particles arranged in at least a part of the plurality of recesses (preparation step) and the surface of the substrate (preparation step). By providing a composition layer containing a photocurable component and a first thermosetting component on the surface on which the recess is formed), the conductive particles are transferred to the composition layer (transfer step). By irradiating the composition layer with light, a first adhesive layer containing a plurality of conductive particles, a cured product of a photocurable component, and a first thermosetting component is formed (light irradiation step). A second adhesive layer containing a second thermosetting component is provided on one surface of the first adhesive layer (lamination step).

Hereinafter, the method for manufacturing the circuit connection adhesive film will be described with reference to FIGS. 5 to 10 by taking the above-mentioned method for manufacturing the circuit connection adhesive film 10A as an example.

FIG. 5 is a diagram schematically showing a vertical cross section of a substrate used in a method for manufacturing an adhesive film 10A for circuit connection. FIG. 6 is a diagram showing a modified example of the cross-sectional shape of the recess of the substrate of FIG. FIG. 7 is a cross-sectional view schematically showing a state in which the conductive particles 4 are arranged in the recesses of the substrate of FIG. FIG. 8 is a cross-sectional view schematically showing an example of the preparation process. FIG. 9 is a cross-sectional view schematically showing an example of the transfer process. FIG. 10 is a cross-sectional view schematically showing an example of a light irradiation process.

(Preparation process)
In the preparation step, first, a substrate 6 having a plurality of recesses 7 on the surface is prepared (see FIG. 5). The substrate 6 has a plurality of recesses 7. The plurality of recesses 7 are regularly arranged, for example, in a predetermined pattern (for example, a pattern corresponding to an electrode pattern of a circuit member). When the recesses 7 are arranged in a predetermined pattern, the conductive particles 4 are transferred to the composition layer in a predetermined pattern. Therefore, a circuit connection adhesive film 10A in which the conductive particles 4 are regularly arranged in a predetermined pattern (a pattern as shown in FIGS. 2 and 3) can be obtained.

As shown in FIG. 5, for example, the recess 7 of the substrate 6 may be formed in a tapered shape in which the opening area expands from the bottom 7a side of the recess 7 toward the surface 6a side of the substrate 6. That is, the width of the bottom portion 7a of the recess 7 (width a in FIG. 5) may be narrower than the width of the opening of the recess 7 (width b in FIG. 5). The size of the recess 7 (width a, width b, volume, taper angle, depth, etc.) can be set according to the size of the target conductive particles and the position of the conductive particles in the circuit connection adhesive film. For example, the width (width b) of the opening of the recess 7 may be larger than the maximum particle diameter of the conductive particles 4 and may be less than twice the maximum particle diameter of the conductive particles.

The shape of the recess 7 (the cross-sectional shape of the recess 7) in the vertical cross section of the substrate 6 may be, for example, the shape shown in FIGS. 6A to 6H. In any of the cross-sectional shapes shown in FIGS. 6A to 6H, the width (width b) of the opening of the recess 7 is the maximum width in the cross-sectional shape. As a result, the conductive particles arranged in the recess 7 can be easily taken out, and workability is improved.

The shape of the opening of the recess 7 may be a circle, an ellipse, a triangle, a quadrangle, a polygon, or the like.

The recess 7 of the substrate 6 can be formed by a known method such as lithography or machining. In these methods, the size and shape of the recess can be freely designed.

As the material constituting the substrate 6, for example, an inorganic material such as a metal such as silicon, various ceramics, glass, and stainless steel, and an organic material such as various resins can be used. As will be described later, in the manufacturing method of the present embodiment, the conductive particles 4 can be arranged in the recesses 7 of the substrate 6 by forming the conductive particles 4 in the recesses 7 of the substrate 6. In this case, the substrate 6 can be arranged. May have heat resistance that does not deteriorate at the melting temperature of the fine particles (for example, solder fine particles) used for forming the conductive particles 4.

Next, the conductive particles 4 (component (A) above) are arranged (accommodated) in at least a part (part or all) of the plurality of recesses 7 of the substrate 6 (see FIG. 7).

The method of arranging the conductive particles 4 is not particularly limited. The arrangement method may be either dry type or wet type. For example, the conductive particles 4 are placed on the surface 6a of the substrate 6, and the surface 6a of the substrate 6 is rubbed with a squeegee or a fine adhesive roller to remove the excess conductive particles 4 while removing the conductive particles in the recess 7. 4 can be arranged. When the width b of the opening of the recess 7 is larger than the depth of the recess 7, conductive particles may pop out from the opening of the recess 7. When a squeegee is used, conductive particles protruding from the opening of the recess 7 are removed. As a method for removing excess conductive particles, there is also a method of rubbing the surface 6a of the substrate 6 with a non-woven fabric or a bundle of fibers by blowing compressed air. Since these methods have a weaker physical force than squeegees, they are preferable in handling easily deformable particles (for example, solder particles) as conductive particles.

When solder particles are used as the conductive particles 4, the conductive particles 4 may be arranged in the recesses 7 by forming the conductive particles 4 (solder particles) in the recesses 7 of the substrate 6. Specifically, for example, as shown in FIGS. 8A to 8B, fine particles 8 (solder fine particles) for forming conductive particles 4 are housed in the recesses 7 and then housed in the recesses 7. By melting the formed fine particles 8, the conductive particles 4 can be formed in the recess 7. The fine particles 8 housed in the recess 7 are united by melting and spheroidized by surface tension. At this time, at the contact portion of the recess 7 with the bottom portion 7a, the molten metal has a shape that follows the bottom portion 7a. Therefore, for example, when the bottom portion 7a of the recess 7 has a flat shape as shown in FIG. 8A, the conductive particles 4 are flat on a part of the surface as shown in FIG. 8B. It has a part 4a.

The fine particles 8 may be accommodated in the recesses 7, and the particle size distribution may vary widely or the shape may be distorted.

Examples of the method of melting the fine particles 8 contained in the recess 7 include a method of heating the fine particles 8 to a temperature higher than the melting point of the material forming the fine particles. The fine particles 8 may not melt, do not spread, or do not coalesce even when heated at a temperature equal to or higher than the melting point due to the influence of the oxide film. Therefore, the fine particles 8 may be exposed to a reducing atmosphere to remove the surface oxide film of the fine particles 8, and then heated to a temperature equal to or higher than the melting point of the fine particles 8. This facilitates melting, wetting and spreading the fine particles 8 and unifying them. From the same viewpoint, the fine particles 8 may be melted in a reducing atmosphere.

The method for creating a reducing atmosphere is not particularly limited as long as the above effect can be obtained, and for example, there is a method using hydrogen gas, hydrogen radical, formic acid gas and the like. For example, by using a hydrogen reduction furnace, a hydrogen radical reduction furnace, a formic acid reduction furnace, or a conveyor furnace or a continuous furnace thereof, the fine particles 8 can be melted in a reducing atmosphere. These devices may be equipped with a heating device, a chamber filled with an inert gas (nitrogen, argon, etc.), a mechanism for evacuating the inside of the chamber, etc., which makes it easier to control the reduced gas. Become. Further, if the inside of the chamber can be evacuated, the voids can be removed by reducing the pressure after the fine particles 8 are melted and united, and the conductive particles 4 having further excellent connection stability can be obtained.

The profile of the reduction of the fine particles 8, the melting conditions, the temperature, the adjustment of the atmosphere in the furnace, etc. may be appropriately set in consideration of the melting point of the fine particles 8, the particle size, the size of the recess, the material of the substrate 6, and the like.

According to the above method, conductive particles 4 having a substantially uniform size can be formed regardless of the material and shape of the fine particles 8. Further, since the size and shape of the conductive particles 4 depend on the amount of fine particles 8 accommodated in the recesses 7, the shape of the recesses 7, and the like, the conductive particles 4 are designed by designing the recesses 7 (adjusting the size, shape, etc. of the recesses). Conductive particles that can be freely designed in size and shape and have a desired particle size distribution (for example, conductive particles having an average particle size of 1 to 30 μm and a CV value of the particle size of 20% or less). Can be easily prepared.

The above method is particularly suitable when the conductive particles 4 are indium-based solder particles. Indium-based solder can be deposited by plating, but it is difficult to precipitate it in the form of particles, and it is a soft and difficult material to handle. However, in the above method, by using indium-based solder fine particles as a raw material, indium-based solder particles having a substantially uniform particle size can be easily produced.

After the conductive particles 4 are arranged in the recesses 7, the substrate 6 can be handled with the conductive particles 4 arranged (accommodated) in the recesses 7. For example, when the substrate 6 is transported and stored in a state where the conductive particles 4 are arranged (accommodated) in the recess 7, the deformation of the conductive particles 4 (particularly soft conductive particles such as solder particles) can be prevented. Further, in the state where the conductive particles 4 are arranged (accommodated) in the recess 7, the conductive particles 4 can be easily taken out, so that deformation when the conductive particles 4 are collected, surface-treated, or the like can be easily prevented.

(Transfer process)
In the transfer step, a photocurable component (component (B) above) and a first thermosetting component (component (C) above) are contained on the surface of the substrate 6 (the surface on which the recess 7 is formed). By providing the composition layer 9, the conductive particles 4 are transferred to the composition layer 9 (see FIG. 9).

Specifically, first, the composition layer 9 containing the component (B) and the component (C) is formed on the support 11 to obtain the laminated film 12, and then the recess 7 of the substrate 6 is formed. The surface (surface of the substrate 6) 6a and the surface of the laminated film 12 on the composition layer 9 side (surface 9a on the side opposite to the support 11 of the composition layer 9) are opposed to the substrate 6 and the composition. Bring it closer to layer 9 (see (a) in FIG. 9). Next, by adhering the laminated film 12 and the substrate 6, the composition layer 9 is brought into contact with the surface (the surface on which the recess 7 is formed) 6a of the substrate 6, and the conductive particles 4 are transferred to the composition layer 9. do. As a result, a particle transfer layer 13 including the composition layer 9 and the conductive particles 4 having at least a part embedded in the composition layer 9 is obtained (see (b) of FIG. 9). At this time, when the bottom portion of the concave portion 7 is flat, the conductive particles 4 have a flat surface portion 4a corresponding to the shape of the bottom portion of the concave portion 7, and the flat surface portion 4a faces the opposite side to the support 11. In the state, it is arranged in the composition layer 9.

The composition layer 9 is prepared by dissolving or dispersing the component (B) and the component (C), and other components added as necessary by stirring and mixing, kneading, etc. in an organic medium. , Can be formed using a varnish composition (a varnish-like first adhesive composition). Specifically, for example, the varnish composition is applied onto the support 11 (for example, a base material that has been subjected to a mold release treatment) using a knife coater, a roll coater, an applicator, a comma coater, a die coater, or the like, and then heated. The composition layer 9 can be formed by volatilizing the organic medium. At this time, the thickness of the finally obtained first adhesive layer (first adhesive film) can be adjusted by adjusting the coating amount of the varnish composition.

The organic medium used in the preparation of the varnish composition is not particularly limited as long as it has the property of being able to dissolve or disperse each component substantially uniformly. Examples of such an organic medium include toluene, acetone, methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate, propyl acetate, butyl acetate and the like. These organic media can be used alone or in combination of two or more. Stirring and mixing or kneading in the preparation of the varnish composition can be carried out by using, for example, a stirrer, a raider, a three-roll, a ball mill, a bead mill, a homodisper or the like.

The support 11 is not particularly limited as long as it has heat resistance that can withstand the heating conditions when volatilizing the organic medium. The support 11 may be a plastic film or a metal foil. Examples of the support 11 include stretched polypropylene (OPP), polyethylene terephthalate (PET), polyethylene naphthalate, polyethylene isophthalate, polyvinylidene terephthalate, polyolefin, polyacetate, polycarbonate, polyphenylene sulfide, polyamide, polyimide, cellulose, and ethylene. A substrate (for example, a film) made of a vinyl acetate copolymer, polyvinyl chloride, polyvinylidene chloride, a synthetic rubber, a liquid crystal polymer, or the like may be used.

The heating conditions for volatilizing the organic medium from the varnish composition applied to the base material can be appropriately set according to the organic medium to be used and the like. The heating conditions may be, for example, 40 to 120 ° C. for 0.1 to 10 minutes.

Examples of the method of laminating the laminated film 12 and the substrate 6 include a heat press, a roll laminating, and a vacuum laminating method. Lamination can be performed, for example, under temperature conditions of 0 to 80 ° C.

In the transfer step, the composition layer 9 may be formed by directly applying the varnish composition to the substrate 6, but by using the laminated film 12 as in the above method, the support 11 and the composition layer 9 may be formed. It becomes easy to obtain a particle transfer layer 13 in which the conductive particles 4 and the conductive particles 4 are integrated, and there is a tendency that the light irradiation step described later can be easily carried out.

(Light irradiation process)
In the light irradiation step, the composition layer 9 (particle transfer layer 13) is irradiated with light (active light rays) to cure the component (B) in the composition layer 9 to form the first adhesive layer 1. (See FIG. 10).

For the irradiation of light, irradiation light (for example, ultraviolet light) containing a wavelength in the range of 150 to 750 nm may be used. Light irradiation can be performed using, for example, a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a xenon lamp, a metal halide lamp, an LED light source, or the like. The integrated amount of light to be irradiated can be appropriately set, and may be, for example, 500 to 3000 mJ / cm ² .

As shown by the arrow in FIG. 10A, in FIG. 10A, light is irradiated from the side opposite to the support 11 (the side in which the conductive particles 4 are transferred in the composition layer 9). However, when the support 11 transmits light, the light may be irradiated from the support 11 side. Further, in FIG. 10A, light irradiation is performed after the substrate 6 and the particle transfer layer 13 are separated, but light irradiation may be performed before the separation of the substrate 6. In this case, light may be irradiated after the support 11 is peeled off.

(Laminating process)
In the laminating step, the second adhesive layer 2 is provided on the surface of the first adhesive layer 1 opposite to the support 11 (the side in which the conductive particles 4 are transferred in the composition layer 9). As a result, the circuit connection adhesive film 10A shown in FIG. 1 is obtained.

The second adhesive layer 2 replaces the varnish-like first adhesive composition with a second thermosetting component (component (C) above) and other components added as needed. The composition layer 9 is used as a substrate, except that a varnish composition (a varnish-like second adhesive composition) prepared by dissolving or dispersing by stirring and mixing, kneading, etc. in an organic medium is used. It can be provided on the first adhesive layer 1 in the same manner as the method provided on 6. That is, the second adhesive layer is placed on the first adhesive layer 1 by adhering the laminated film obtained by forming the second adhesive layer 2 on the support and the first adhesive layer 1. 2 may be provided, and the second adhesive layer 2 may be provided on the first adhesive layer 1 by directly applying the varnish-like second adhesive composition to the first adhesive layer 1. good.

In the laminating step, by providing the second adhesive layer 2 on the surface opposite to the support 11 as in the above method, the adhesive film for circuit connection to the circuit member is improved and connected. It can be expected to suppress peeling at times. In the laminating step, the second adhesive layer 2 may be provided on the surface on the side where the support 11 is provided after the support 11 is peeled off. In this case, the laminating step may be performed before the light irradiation step or may be performed before the transfer step.

Although the method for producing the circuit connection adhesive film of one embodiment has been described above by taking the method for producing the circuit connection adhesive film 10A as an example, the present invention is not limited to the above embodiment.

For example, in the method of manufacturing an adhesive film for circuit connection, a third adhesive layer is provided on a surface of the first adhesive layer opposite to the second adhesive layer (second laminating step). ) May be further included. In this method, a circuit connection adhesive film (for example, the circuit connection adhesive film 10B shown in FIG. 4) further including a third adhesive layer is obtained.

In the second laminating step, instead of the second adhesive composition, a composition containing a third thermosetting component (the above component (C)) and other components added as needed (the above-mentioned component (C)). A third adhesive layer is provided on the first adhesive layer in the same manner as in the above-mentioned laminating step (first laminating step) for providing the second adhesive layer, except that the third adhesive composition) is provided. An adhesive layer can be provided. The second laminating step may be carried out before the first laminating step.

<Connection structure and its manufacturing method>
Hereinafter, a connection structure (circuit connection structure) and a method for manufacturing the same will be described by taking as an example an embodiment in which the above-mentioned adhesive film 10A for circuit connection is used as the circuit connection material.

FIG. 11 is a schematic cross-sectional view showing an embodiment of the connection structure. As shown in FIG. 11, the connection structure 100 includes a first circuit member 23 having a first electrode 22 formed on the main surface 21a of the first circuit board 21 and the first circuit board 21. A second circuit member 26 having a second electrode 25 formed on the main surface 24a of the second circuit board 24 and the second circuit board 24, and a cured body of the circuit connection adhesive film 10A are included. The first electrode 22 and the second electrode 25 are electrically connected to each other via the conductive particles 4 (or the molten solidified product of the conductive particles 4), and the first circuit member 23 and the second circuit member 26 It is provided with a connection portion 27 for adhering the above.

The first circuit member 23 and the second circuit member 26 may be the same or different from each other. The first circuit member 23 and the second circuit member 26 are a glass substrate or a plastic substrate on which a circuit electrode is formed; a printed wiring board; a ceramic wiring board; a flexible wiring board; an IC chip such as a drive IC, or the like. It's okay. The first circuit board 21 and the second circuit board 24 may be made of an inorganic substance such as semiconductor, glass, or ceramic, an organic substance such as polyimide or polycarbonate, or a composite such as glass / epoxy. The first circuit board 21 may be a plastic substrate. The first circuit member 23 may be, for example, a plastic substrate (a plastic substrate made of an organic substance such as polyimide, polycarbonate, polyethylene terephthalate, or cycloolefin polymer) on which a circuit electrode is formed, and may be a second circuit. The member 26 may be, for example, an IC chip such as a drive IC. In the plastic substrate on which the electrodes are formed, a display region is formed by regularly arranging a pixel drive circuit such as an organic TFT or a plurality of organic EL elements R, G, and B on the plastic substrate in a matrix. It may be the one.

The first electrode 22 and the second electrode 25 are gold, silver, tin, ruthenium, rhodium, palladium, osmium, iridium, platinum, copper, aluminum, molybdenum, titanium and other metals, indium tin oxide (ITO), and the like. It may be an electrode containing an oxide such as indium zinc oxide (IZO) or indium gallium zinc oxide (IGZO). The first electrode 22 and the second electrode 25 may be electrodes formed by laminating two or more of these metals, oxides, and the like. The electrode formed by stacking two or more types may have two or more layers, and may have three or more layers. The first electrode 22 and the second electrode 25 may be circuit electrodes or bump electrodes. In FIG. 11, the first electrode 22 is a circuit electrode and the second electrode 25 is a bump electrode.

The connecting portion 27 is located, for example, on the side of the first circuit member 23 in the direction in which the first circuit member 23 and the second circuit member 26 face each other (hereinafter referred to as “opposing direction”), and the above-mentioned first circuit member 27 is located. It is located on the second circuit member 26 side in the opposite direction to the first region 28 containing the cured product of the component (B) and the cured product of the component (C) other than the conductive particles 4 in the adhesive layer, and is described above. The first electrode 22 and the second electrode 25 are interposed between the second region 29 containing the cured product such as the component (C) in the second adhesive layer and at least the first electrode 22 and the second electrode 25. It has conductive particles 4 (or molten solidified products of conductive particles 4) that electrically connect the electrodes 25 of 2 to each other. The connection portion 27 does not have to have two distinct regions between the first region 28 and the second region 29, and the cured product derived from the first adhesive layer and the second region 27. A cured product derived from the adhesive layer may be mixed to form one region.

As the connection structure, for example, a flexible organic electric field light emitting color display (organic EL display) in which a plastic substrate in which organic EL elements are regularly arranged and a drive circuit element which is a driver for image display are connected. Examples thereof include a touch panel in which a plastic substrate on which organic EL elements are regularly arranged and a position input element such as a touch pad are connected. The connection structure can be applied to various monitors such as smart phones, tablets, televisions, vehicle navigation systems, wearable terminals, furniture; home appliances; daily necessities and the like.

FIG. 12 is a schematic cross-sectional view showing an embodiment of a method for manufacturing the connection structure 100. 12A and 12B are schematic cross-sectional views showing each step. As shown in FIG. 12, in the method of manufacturing the connection structure 100, a surface provided with the first electrode 22 of the first circuit member 23 and a second electrode 25 of the second circuit member 26 are provided. A laminated body including the above-mentioned circuit connection adhesive film 10A and the first circuit member 23, the circuit connection adhesive film 10A, and the second circuit member 26. Is heated in a state of being pressed in the thickness direction of the laminated body, so that the first electrode 22 and the second electrode 25 are electrically connected to each other via the conductive particles 4 (or the molten solidified product of the conductive particles 4). Including connecting to and bonding the first circuit member 23 and the second circuit member 26.

Specifically, first, the first circuit board 23 including the first electrode 22 formed on the main surface 21a of the first circuit board 21 and the first circuit board 21, and the second circuit board 24. And a second circuit member 26 having a second electrode 25 formed on the main surface 24a of the second circuit board 24 are prepared.

Next, the first circuit member 23 and the second circuit member 26 are arranged so that the first electrode 22 and the second electrode 25 face each other, and the first circuit member 23 and the second circuit member are arranged. A circuit connection adhesive film 10A is placed between the 26 and the 26. For example, as shown in FIG. 12A, the circuit connection adhesive film 10A is placed on the first circuit member so that the first adhesive layer 1 side faces the main surface 21a of the first circuit board 21. Laminate on 23. Next, the circuit connection adhesive film 10A was laminated so that the first electrode 22 on the first circuit board 21 and the second electrode 25 on the second circuit board 24 face each other. The second circuit member 26 is arranged on the first circuit member 23.

Then, as shown in FIG. 12 (b), the laminated body in which the first circuit member 23, the circuit connection adhesive film 10A, and the second circuit member 26 are laminated in this order is the laminated body. By heating while pressing in the thickness direction of the body, the first circuit member 23 and the second circuit member 26 are thermocompression-bonded to each other. At this time, as shown by the arrows in FIG. 12B, the fluidable uncured thermosetting components contained in the first adhesive layer 1 and the second adhesive layer 2 are adjacent to each other. It flows so as to fill the voids between the electrodes (the voids between the first electrodes 22 and the voids between the second electrodes 25), and is cured by the above heating. As a result, the first electrode 22 and the second electrode 25 are electrically connected to each other via the conductive particles 4, and the first circuit member 23 and the second circuit member 26 are adhered to each other. The connection structure 100 shown in 11 is obtained.

In the method for manufacturing the connection structure 100, since a part of the first adhesive layer 1 is cured by light irradiation, the flow of conductive particles in the first adhesive layer 1 is suppressed, so that it is conductive. Particles are efficiently trapped between opposing electrodes. Further, since the thermosetting component contained in the first adhesive layer 1 and the second adhesive layer 2 flows during thermocompression bonding, the conductive particles 4 and the electrodes (the first electrode and the second electrode) are connected after the connection. It becomes difficult for the resin to intervene between the electrodes), and the connection resistance between the first electrode 22 and the second electrode 25 facing each other is reduced.

When solder particles are used as conductive particles, the solder particles are melted and gathered together between the first electrode 22 and the second electrode 25 to form a solder layer, which is then cooled to form the first electrode. A solder layer is fixed between the 22 and the second electrode 25, and the first electrode 22 and the second electrode 25 are electrically connected to each other.

The heating temperature at the time of connection can be appropriately set, but may be, for example, 50 to 190 ° C. When the solder particles are used as the conductive particles, the temperature may be any temperature at which the solder particles can be melted (for example, a temperature higher than the melting point of the solder particles), and may be, for example, 130 to 260 ° C. The pressurization is not particularly limited as long as it does not damage the adherend, but in the case of COP mounting, for example, the area conversion pressure at the bump electrode may be 0.1 to 50 MPa, and may be 40 MPa or less. It may be 0.1 to 40 MPa. Further, in the case of COG mounting, for example, the area conversion pressure at the bump electrode may be 10 to 100 MPa. These heating and pressurizing times may be in the range of 0.5 to 120 seconds.

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

In the examples and comparative examples, the materials shown below are referred to as (B1) component, (B2) component, (C1) component, (C2) component, (C3) component, (C4) component, (D) component, and (E). ) And component (F).
(B1) Ingredients: Radical Polymerizable Compound-NK Ester A-BPEF (9,9-bi [4- (2-acryloyloxyethoxy) phenyl] fluorene, manufactured by Shin Nakamura Chemical Industry Co., Ltd.)
・ Lipoxy VR-90 (bisphenol A type epoxy methacrylate, manufactured by Showa Denko KK)
・ Cyclomer M100 (3,4-epoxycyclohexylmethylmethacrylate, manufactured by Daicel Corporation)
・ A-1000 (polyethylene glycol diacrylate, manufactured by Shin-Nakamura Chemical Co., Ltd.)
-A9300-1CL (caprolactone-modified tris- (2-acryloxyethyl) isocyanurate, manufactured by Shin-Nakamura Chemical Industry Co., Ltd.)
(B2) Ingredient: Photo-Radical Polymerization Initiator-Irgacure OXE-02 (1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazole-3-yl] -etanone 1- (O-acetyloxime) , Made by BASF Japan Ltd.)
Omnirad907 (2-methyl-1- [4- (methylthio) phenyl] -2-morphonilopropan-1-one, manufactured by IGM RESINS B.V.)
(C1) Ingredient: Cationic Polymerizable Compound-ETERNACOLL OXBP (4,4'-bis [(3-ethyl-3-oxetanyl) methoxymethyl] biphenyl, manufactured by Ube Kosan Co., Ltd.)
-Seroxide 8010 (B-7-oxabicyclo [4.1.0] heptane, manufactured by Daicel Corporation)
・ JER1010 (bisphenol A type epoxy resin, manufactured by Mitsubishi Chemical Corporation)
・ YL983U (bisphenol F type epoxy resin, manufactured by Mitsubishi Chemical Corporation)
(C2) Component: Thermal cation polymerization initiator (thermal latent cation generator)
CXC-1821 (quaternary ammonium salt type thermoacid generator, manufactured by King Industries),
・ SI-60L (aromatic sulfonium salt type thermoacid generator, manufactured by Sanshin Chemical Co., Ltd.)
(C3) Component: Anionic polymerizable compound-HP-4032D (1,6-bis (oxylanylmethoxy) naphthalene, manufactured by DIC Corporation)
(C4) Component: Thermal Anionic Polymerization Initiator (Thermal Potential Anion Generator)
・ HX-3941HP (microcapsule type imidazole-based curing accelerator, manufactured by Asahi Kasei Corporation)
(D) Component: Thermoplastic resin ・ P-1: Fluorene type phenoxy resin synthesized by the method described later ・ YP-70 (bisphenol A / bisphenol F copolymer type phenoxy resin, manufactured by Nittetsu Chemical & Materials Co., Ltd.)
(E) Ingredient: Coupling agent-KBM-403 (γ-glycidoxypropyltrimethoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd.)
(F) Component: Filler-Aerosil R805 (hydrolyzed product of trimethoxyoctylsilane and silica (silica fine particles), manufactured by Evonik Industries AG, diluted to 10% by mass of non-volatile content with an organic solvent)

(Synthesis of P-1)
4,4'-(9-fluorenylidene) -diphenol 45 g (manufactured by Sigma Aldrich Japan Co., Ltd.) and 3,3', 5,5'-tetramethylbiphenol diglycidyl ether 50 g (YX-4000H, Mitsubishi Chemical Corporation) Is dissolved in 1000 mL of N-methylpyrrolidone in a 3000 mL three-necked flask equipped with a Dimroth condenser, a calcium chloride tube, and a Teflon stirring rod (“Teflon” is a registered trademark) connected to a stirring motor. It was used as a reaction solution. 21 g of potassium carbonate was added thereto, and the mixture was stirred while heating to 110 ° C. with a mantle heater. After stirring for 3 hours, the reaction solution was added dropwise to a beaker containing 1000 mL of methanol, and the generated precipitate was collected by suction filtration. The precipitate collected by filtration was further washed 3 times with 300 mL of methanol to obtain 75 g of phenoxy resin P-1.

Then, the molecular weight of the phenoxy resin P-1 was measured using a high performance liquid chromatograph GP8020 manufactured by Tosoh Corporation (column: GelpacGL-A150S and GLA160S manufactured by Hitachi Chemical Co., Ltd., eluent: tetrahydrofuran, flow velocity: 1.0 ml / min. ). As a result, it was Mn = 15769, Mw = 38045, and Mw / Mn = 2.413 in terms of polystyrene.

<Example 1>
(Step (a): Preparation step)
[Step (a1): Preparation of substrate]
A substrate (PET film, thickness: 55 μm) having a plurality of recesses on the surface was prepared. The concave portion has a truncated cone shape in which the opening area expands toward the surface side of the substrate (when viewed from the upper surface of the opening, the center of the bottom and the center of the opening are the same), the opening diameter is 4.3 μmφ, and the bottom diameter is 4. The diameter was 0.0 μm φ and the depth was 4.0 μm. Further, the plurality of recesses were regularly formed in a three-way arrangement at an interval of 6.2 μm (distance between the centers of the bottoms) so as to be 29,000 per 1 mm square.

[Step (a2): Arrangement of conductive particles]
As a component (A), conductive particles (average particle diameter: 3.3 μm, particle diameter C.I.) in which a nickel layer having a thickness of 0.15 μm is formed on the surface of a nucleus (particle) made of plastic (crosslinked polystyrene). A V. value: 2.8% and a specific gravity: 2.9) were prepared and placed on the surface on which the recesses of the substrate were formed. Next, excess conductive particles were removed by rubbing the surface of the substrate on which the recesses were formed with a fine adhesive roller, and the conductive particles were arranged only in the recesses. The average particle diameter of the conductive particles and the C.I. V. The value is 300 pieces after the first adhesive layer prepared through the steps (b) and (c) described later is cut out to a size of 10 cm × 10 cm, and Pt sputtering is applied to the surface on which the conductive particles are arranged. It is a value measured by SEM observation of conductive particles.

(Step (b): Transfer step)
[Step (b1): Preparation of composition layer]
The blending amounts (unit: mass) of the (B1) component, (B2) component, (C1) component, (C2) component, (D) component, (E) component and (F) component shown in Table 1 are shown in Table 1. A resin solution was obtained by mixing with an organic solvent (2-butanone). Next, this resin solution was applied to a 38 μm-thick PET film that had been mold-released with silicone, and dried with hot air at 60 ° C. for 3 minutes to prepare a composition layer having a thickness of 1.5 μm on the PET film.

[Step (b2): Transfer of conductive particles]
The composition layer formed on the PET film produced in the step (b1) and the substrate prepared in the step (a) in which the conductive particles are arranged in the recesses are arranged facing each other on the composition layer. Conductive particles were transferred.

(Step (c): Light irradiation step)
A UV curing furnace (UVC-2534 / 1MNLC3-XJ01 manufactured by Ushio Electric Co., Ltd.) was used from the side where the conductive particles were transferred to the composition layer on which the conductive particles were transferred using a metal halide lamp, and the integrated light intensity was 1700 mJ. The component (B2) was activated and the component (B1) was polymerized by irradiating with ultraviolet rays of / cm ² (wavelength: 365 nm). As a result, the photocurable components ((B1) component and (B2) component) in the composition layer were cured to form the first adhesive layer.

(Step (d): Laminating step)
[Step (d1): Preparation of second adhesive layer]
The organic solvent (2) of the component (C1), the component (C2), the component (D), the component (E) and the component (F) shown in Table 2 in the blending amount (unit: parts by mass, solid content) shown in Table 2. -Mixed with butanone) to obtain a resin solution. Next, this resin solution was applied to a 50 μm-thick PET film that had been mold-released with silicone, and dried with hot air at 60 ° C. for 3 minutes to form a second adhesive layer with a thickness of 12.5 μm on the PET film. Made.

[Step (d2): Laminating the second adhesive layer]
The first adhesive layer prepared in the step (c) and the second adhesive layer prepared in the step (d1) were bonded together while applying a temperature of 50 ° C. As a result, a two-layered anisotropic conductive adhesive film (thickness: 14 μm) was obtained.

<Example 2>
An anisotropic conductive adhesive film was produced in the same manner as in Example 1 except that the following steps (e) were performed in addition to the steps (a) to (d).

(Step (e): Second laminating step)
[Step (e1): Preparation of third adhesive layer]
The organic solvent (2) of the component (C1), the component (C2), the component (D), the component (E) and the component (F) shown in Table 3 in the blending amount (unit: parts by mass, solid content) shown in Table 3. -Mixed with butanone) to obtain a resin solution. Next, this resin solution was applied to a 50 μm-thick PET film that had been mold-released from silicone, and dried with hot air at 60 ° C. for 3 minutes to form a second 2.0 μm-thick adhesive layer on the PET film. Made.

[Step (e2): Laminating a third adhesive layer]
The first adhesive layer exposed by peeling off the PET film on the first adhesive layer side of the anisotropic conductive adhesive film prepared in the step (d2), and the third adhesive layer prepared in the step (e1). The adhesive layer was bonded while applying a temperature of 50 ° C. As a result, an anisotropic conductive adhesive film (thickness: 16 μm) having a three-layer structure was obtained.

<Examples 3 to 10, Comparative Example 1>
An anisotropic conductive adhesive film having a three-layer structure was produced in the same manner as in Example 2 except that the types and / or blending amounts of the components to be blended were changed as shown in Table 4 in the step (b1). bottom.

<Example 11>
An anisotropic conductive adhesive film having a three-layer structure was produced in the same manner as in Example 10 except that the integrated light amount of the irradiated light was changed to 2000 mJ / cm ² in the step (c).

<Example 12>
An anisotropic conductive adhesive film having a three-layer structure was produced in the same manner as in Example 10 except that the integrated light amount of the irradiated light was changed to 2300 mJ / cm ² in the step (c).

<Example 13>
In step (b1), except that 1.0 part by mass of Omnirad 907 was used instead of Irgacure OXE-02 as the component (B2) and the integrated light amount was changed to 2000 mJ / cm ² . In the same manner as in Example 2, a three-layered anisotropic conductive adhesive film was produced.

<Example 14>
In step (b1) and step (d1), 40 parts by mass of YL983U was used as the component (C1) instead of ETENRNACOLL OXBP and seroxide 8010, and instead of CXC-1821 as the component (C2). An anisotropic conductive adhesive film having a two-layer structure was produced in the same manner as in Example 1 except that 7 parts by mass of SI-60L was used.

<Example 15>
In the step (b1) and the step (d1), 10 parts by mass of HP-4032D was used as the component (C3) instead of the component (C1), and the component (C4) was replaced with the component (C2). As a result, an anisotropic conductive adhesive film having a two-layer structure was produced in the same manner as in Example 1 except that 40 parts by mass of HX-3941HP was used.

<Example 16>
Instead of the step (a2), the following step (a2') is performed, and the substrate obtained in the following step (a2') is used as the substrate in which the conductive particles are arranged in the recesses, which is used in the step (b2). An anisotropic conductive adhesive film having a two-layer structure was produced in the same manner as in Example 1 except that it was used.

[Step (a2'): Preparation and placement of solder particles]
100 g of Sn-Bi solder fine particles (manufactured by 5N Plus, melting point 138 ° C., Type 8) were immersed in distilled water, ultrasonically dispersed, and then leveled to recover the solder fine particles floating in the supernatant. This operation was repeated to recover 10 g of solder fine particles. The average particle size of the obtained solder fine particles was 1.0 μm, and the particle size was C.I. V. The value was 42%. Next, the obtained solder fine particles (average particle diameter: 1.0 μm, CV value of particle diameter: 42%) are placed on the surface of the substrate prepared in the step (a1) where the recesses are formed. bottom. Next, excess solder fine particles were removed by rubbing the surface of the substrate on which the concave portions were formed with a fine adhesive roller, and the solder fine particles were arranged only in the concave portions. Next, the substrate in which the solder fine particles are arranged in the recesses is put into a hydrogen radical reduction furnace (hydrogen plasma reflow device manufactured by Shinko Seiki Co., Ltd.), and after evacuation, hydrogen gas is introduced into the furnace to introduce the inside of the furnace. Was filled with hydrogen gas. Then, the temperature inside the furnace was adjusted to 120 ° C., and hydrogen radicals were irradiated for 5 minutes. After that, hydrogen gas in the furnace is removed by vacuuming, and after heating to 145 ° C, nitrogen is introduced into the furnace to return it to atmospheric pressure, and then the temperature in the furnace is lowered to room temperature to form solder particles. bottom. As a result, a substrate in which conductive particles (solder particles) were arranged in the concave portions, which was used in the step (b2), was prepared.

Solder particles were separately prepared by the same operation, and the obtained solder particles were recovered from the recesses by tapping the back side of the recesses of the substrate. It was confirmed that the solder particles had a flat surface portion on a part of the surface, and the ratio (B / A) of the diameter B of the flat surface portion to the diameter A of the solder particles was 0.15. Further, when a quadrangle circumscribing the projected image of the solder particles was created by two pairs of parallel lines, Y / X was 0.93 when the distance between the opposite sides was X and Y (however, Y <X). I confirmed that. In addition, the average particle diameter of the solder particles and the C.I. V. When the value was measured, the average particle size was 3.8 μm, and the particle size C.I. V. The value was 7.9%. For the average particle diameters of the solder particles, B / A and Y / X, the first adhesive layer produced through the steps (b) and (c) was cut out to a size of 10 cm × 10 cm, and the solder particles were arranged. It is a value measured by SEM observation of 300 solder particles after applying Pt sputtering to the surface.

<Example 17>
An anisotropic conductive adhesive film having a three-layer structure was produced in the same manner as in Example 2 except that the above step (a2') was performed instead of the step (a2).

<Comparative Example 2>
An anisotropic conductive adhesive film having a three-layer structure was produced in the same manner as in Example 2 except that the step (c) was not carried out.

<Evaluation>
(Evaluation of transfer rate of conductive particles)
For the anisotropic conductive adhesive films of Examples 1 to 17 and Comparative Examples 1 and 2, the number of conductive particles per 25,000 μm ² was set to 20 by using a microscope and image analysis software (ImagePro, manufactured by Hakuto Co., Ltd.). The actual measurement was carried out at the same place, the average value was converted into the number of conductive particles per 1 mm ² , and the number was divided by the number of recesses formed in the substrate to measure the transfer rate of the conductive particles (see the following formula). When the transfer rate of the conductive particles is 95% or more, it is judged as "S", when the transfer rate of the conductive particles is 90% or more and less than 95%, it is judged as "A", and the transfer rate of the conductive particles is 80% or more. When it was less than 90%, it was evaluated as "B", and when the transfer rate of the conductive particles was less than 80%, it was evaluated as "C". The results are shown in Tables 5 to 7.
Transfer rate of conductive particles (%) = (average density of the number of conductive particles in the anisotropic conductive adhesive film / density of recesses formed in the substrate) × 100

(Evaluation of capture rate of conductive particles and evaluation of connection resistance)
[Preparation of circuit members]
As the first circuit member (a), on the surface of a non-alkali glass substrate (OA-11, manufactured by Nippon Electric Glass Co., Ltd., outer shape: 38 mm × 28 mm, thickness: 0.3 mm), AlNd (100 nm) / Mo ( A wiring pattern (pattern width: 19 μm, space between electrodes: 5 μm) having a 50 nm) / ITO (100 nm) wiring pattern was prepared. As the first circuit member (b), on the surface of a non-alkali glass substrate (OA-11, manufactured by Nippon Electric Glass Co., Ltd., outer shape: 38 mm × 28 mm, thickness: 0.3 mm), Cr (20 nm) / Au ( A wiring pattern (pattern width: 19 μm, space between electrodes: 5 μm) having a wiring pattern of 200 nm) was prepared. As the second circuit member, an IC chip in which bump electrodes are arranged in two rows in a staggered pattern (outer shape: 0.9 mm × 20.3 mm, thickness: 0.3 mm, bump electrode size: 70 μm × 12 μm, bump electrode Spacing space: 12 μm, bump electrode thickness: 8 μm) was prepared.

[Preparation of connection structure (a)]
The connection structure (a) was produced by using the anisotropic conductive adhesive films of Examples 1 to 13 and Comparative Examples 1 and 2, respectively. The anisotropic conductive adhesive film was placed on the first circuit member (a) so that the first adhesive layer or the third adhesive layer and the first circuit member (a) were in contact with each other. Using a thermocompression bonding device (BS-17U, manufactured by Ohashi Seisakusho Co., Ltd.) consisting of a stage consisting of a ceramic heater and a tool (8 mm x 50 mm), under the conditions of 70 ° C. and 0.98 MPa (10 kgf / cm ² ). By heating and pressurizing for 2 seconds, the anisotropic conductive adhesive film is attached to the first circuit member (a), and the anisotropic conductive adhesive film is separated from the first circuit member (a) on the opposite side. The mold film was peeled off. Next, after aligning the bump electrode of the first circuit member (a) with the circuit electrode of the second circuit member, the mixture is heated and pressurized at 130 ° C. for 5 seconds at 40 MPa to conduct anisotropic conductivity. The second adhesive layer of the sex adhesive film was attached to the second circuit member to prepare the connection structure (a). The temperature is the measured maximum temperature of the anisotropic conductive adhesive film, and the pressure is the value calculated with respect to the total area of the surfaces of the bump electrodes of the second circuit member facing the first circuit member (a). show.

[Preparation of connection structure (b)]
The connection structure (a) except that the anisotropic conductive adhesive film of Example 14 was used as the anisotropic conductive adhesive film and that the film was heated and pressurized at 60 MPa for 5 seconds at 140 ° C. ) Was produced, and the connection structure (b) was produced.

[Preparation of connection structure (c)]
The connection structure (a) except that the anisotropic conductive adhesive film of Example 15 was used as the anisotropic conductive adhesive film and that the film was heated and pressurized at 60 MPa for 5 seconds at 230 ° C. ) Was produced, and the connection structure (c) was produced.

[Preparation of connection structure (d)]
The anisotropic conductive adhesive films of Examples 16 to 17 were used as the anisotropic conductive adhesive films, respectively, and the first circuit member (b) was used instead of the first circuit member (a). The connection structure (d) was prepared in the same manner as the connection structure (a) except that the connection structure (a) was heated and pressurized at 160 ° C. for 5 seconds at 30 MPa.

[Evaluation of capture rate of conductive particles]
In the production of the connection structure (connection structures (a) to (d)) using the anisotropic conductive adhesive films of Examples 1 to 17 and Comparative Examples 1 and 2, between the bump electrode and the circuit electrode. The capture rate of conductive particles was evaluated. Here, the capture rate of the conductive particles means the ratio of the density of the conductive particles on the bump electrode to the density of the conductive particles in the anisotropic conductive adhesive film, and was calculated from the following formula. Further, the average number of conductive particles on the bump electrode was obtained by observing the mounted circuit member from the glass substrate side using a differential interference microscope and measuring the number of captured conductive particles per bump. When the capture rate of the conductive particles is 90% or more, it is judged as "S", when the capture rate of the conductive particles is 80% or more and less than 90%, it is judged as "A", and the capture rate of the conductive particles is 70% or more. When it was less than 80%, it was evaluated as "B", and when the capture rate of conductive particles was less than 70%, it was evaluated as "C". The results are shown in Tables 5 to 7.
Capturing rate of conductive particles (%) = (average number of conductive particles on bump electrode / (bump electrode area x density of conductive particles in anisotropic conductive adhesive film)) x 100

[Evaluation of connection resistance]
Immediately after the production of the connection structure and after the high temperature and high humidity test, the connection resistance at 14 points was measured by the four-terminal measurement method, and the maximum value of the measured connection resistance values was used in Examples 1 to 17 and. The connection resistance of Comparative Examples 1 and 2 was evaluated. The high temperature and high humidity test was carried out by treating the connected structure in a high temperature and high humidity tank having a temperature of 85 ° C. and a humidity of 85% RH for 500 hours. A multimeter (MLR21, manufactured by Kusumoto Kasei Co., Ltd.) was used to measure the connection resistance. When the connection resistance value is less than 1.0Ω, it is judged as "S", when the connection resistance value is 1.0Ω or more and less than 2.5Ω, it is judged as "A", and the connection resistance value is 2.5Ω or more. If it is less than 0Ω, it is judged as "B", if the connection resistance value is 5.0Ω or more and less than 10.0Ω, it is judged as "C", and if the connection resistance value is 10.0Ω or more, it is judged as "D". Evaluated as. The results are shown in Tables 5 to 7.

1 ... 1st adhesive layer, 2 ... 2nd adhesive layer, 3 ... adhesive component, 4 ... conductive particles, 5 ... third adhesive layer, 6 ... substrate, 7 ... recesses, 9 ... composition Layers, 10A, 10B ... Adhesive film for circuit connection, 21 ... First circuit board, 22 ... First electrode (circuit electrode), 23 ... First circuit member, 24 ... Second circuit board, 25 ... Second electrode (bump electrode), 26 ... second circuit member, 27 ... connection portion, 100 ... connection structure.

Claims

To prepare a substrate having a plurality of recesses on the surface and having conductive particles arranged in at least a part of the plurality of recesses.
By providing a composition layer containing a photocurable component and a first thermosetting component on the surface of the substrate, the conductive particles can be transferred to the composition layer.
By irradiating the composition layer with light, a first adhesive layer containing the plurality of the conductive particles, the cured product of the photocurable component, and the first thermosetting component is formed.
A method for producing an adhesive film for circuit connection, comprising providing a second adhesive layer containing a second thermosetting component on one surface of the first adhesive layer.
The photocurable component contains a radically polymerizable compound and a photoradical polymerization initiator.
The method for producing an adhesive film for circuit connection according to claim 1, wherein the first thermosetting component contains a cationically polymerizable compound and a thermally cationic polymerization initiator.
The method for producing an adhesive film for circuit connection according to claim 2, wherein the first thermosetting component contains a compound having a cyclic ether group as the cationically polymerizable compound.
The circuit connection adhesive film according to claim 3, wherein the first thermosetting component contains at least one selected from the group consisting of an oxetane compound and an alicyclic epoxy compound as the cationically polymerizable compound. Production method.
The method for producing an adhesive film for circuit connection according to any one of claims 2 to 4, wherein the photocurable component contains, as the radically polymerizable compound, a compound represented by the following formula (1).

[In the formula (1), R 1 represents a hydrogen atom or a methyl group, and X represents an alkanediyl group having 1 to 3 carbon atoms.
The method for producing an adhesive film for circuit connection according to any one of claims 2 to 5, wherein the photocurable component contains a compound represented by the following formula (I) as the photoradical polymerization initiator. ..

[In formula (I), R 2 , R 3 and R 4 each independently represent an organic group containing a hydrogen atom, an alkyl group having 1 to 20 carbon atoms or an aromatic hydrocarbon group. ]
Any one of claims 2 to 6, wherein the first thermosetting component comprises a salt compound having a cation represented by the following formula (II) or the following formula (III) as the thermocation polymerization initiator. The method for manufacturing an adhesive film for circuit connection according to the section.

[In formula (II), R 5 and R 6 each independently contain a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an organic group containing a substituent or an unsubstituted aromatic hydrocarbon group. Shown, R 7 represents an alkyl group having 1 to 6 carbon atoms. ]

[In formula (III), R 8 and R 9 each independently contain a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an organic group containing a substituent or an unsubstituted aromatic hydrocarbon group. As shown, R 10 and R 11 each independently represent an alkyl group having 1 to 6 carbon atoms. ]
The average particle diameter of the conductive particles is 1 to 30 μm, and the average particle diameter is 1 to 30 μm.
C.I. of the particle diameter of the conductive particles. V. The method for manufacturing an adhesive film for circuit connection according to any one of claims 1 to 7, wherein the value is 20% or less.
The method for manufacturing an adhesive film for circuit connection according to any one of claims 1 to 8, wherein the conductive particles are solder particles.
The method for producing an adhesive film for circuit connection according to claim 9, wherein the solder particles contain at least one selected from the group consisting of tin, tin alloys, indium and indium alloys.
The solder particles are In-Bi alloy, In-Sn alloy, In-Sn-Ag alloy, Sn-Au alloy, Sn-Bi alloy, Sn-Bi-Ag alloy, Sn-Ag-Cu alloy and Sn-Cu alloy. The method for producing an adhesive film for circuit connection according to claim 10, which comprises at least one selected from the group consisting of.
The method for manufacturing an adhesive film for circuit connection according to any one of claims 9 to 11, wherein the solder particles have a flat surface portion on a part of the surface.
The method for producing an adhesive film for circuit connection according to claim 12, wherein the ratio (B / A) of the diameter B of the flat surface portion to the diameter A of the solder particles satisfies the following formula.
0.01 <B / A <1.0
When a quadrangle circumscribing the projected image of the conductive particles is created by two pairs of parallel lines, and the distance between the opposite sides is X and Y (where Y <X), X and Y have the following equations. The method for manufacturing an adhesive film for circuit connection according to any one of claims 1 to 13.
0.8 <Y / X ≦ 1.0
The method for manufacturing an adhesive film for circuit connection according to any one of claims 1 to 14, wherein the plurality of recesses are formed in a predetermined pattern.
An adhesive film for circuit connection containing conductive particles.
A first adhesive layer containing the plurality of conductive particles, a cured product of a photocurable component, and a first thermosetting component, and a second thermosetting layer provided on the first adhesive layer. With a second adhesive layer containing the ingredients,
At least a part of the plurality of conductive particles are arranged in a predetermined pattern in the plan view of the circuit connecting adhesive film, and adjacent conductive particles are arranged with each other in the vertical cross section of the circuit connecting adhesive film. Adhesive films for circuit connection that are lined up horizontally in a separated state.
A first circuit member having a first electrode and
A second circuit member having a second electrode and
The first circuit member comprising the cured body of the adhesive film for circuit connection according to claim 16 and electrically connecting the first electrode and the second electrode to each other via the conductive particles. A connection structure comprising a connection portion for adhering the second circuit member and the second circuit member.
A surface of the first circuit member having the first electrode provided with the first electrode and a surface of the second circuit member having the second electrode provided with the second electrode. The circuit connection adhesive film according to claim 16 is placed between them, and
By heating the laminate including the first circuit member, the adhesive film for connecting the circuit, and the second circuit member in a state of being pressed in the thickness direction of the laminate, the first electrode can be obtained. A method for manufacturing a connection structure, comprising electrically connecting the second electrode to each other via the conductive particles and adhering the first circuit member and the second circuit member to each other.