TW202229487A - Adhesive film for circuit connection, method for manufacturing same, connection structure body, and method for manufacturing same - Google Patents

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, method for producing the same, and connecting structure and method for producing the same

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

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

However, the pitch and area of metal bumps serving as circuit electrodes of liquid crystal driving ICs have been gradually narrowed with the increase in the definition of liquid crystal displays in recent years. Therefore, there is a possibility that the conductive particles in the adhesive flow out between adjacent circuit electrodes to cause a short circuit. This tendency is particularly pronounced in COG installations. If conductive particles flow out between adjacent circuit electrodes, the number of conductive particles captured between the metal bumps and the glass panel decreases, and there is a possibility that the connection resistance between the opposing circuit electrodes increases, resulting in poor connection.

As a method to solve these problems, a method of forming composite particles (insulation-coated conductive particles) by attaching a plurality of insulating particles (daughter particles) to the surfaces of conductive particles (mother particles) has been proposed. For example, Patent Document 1 proposes a method of attaching spherical resin particles to the surfaces of conductive particles.

[Patent Document 1] Japanese Patent No. 4773685

In order to solve the above-mentioned problems without using the above-mentioned insulating-coated conductive particles, the inventors of the present invention examined the production of an adhesive film for circuit connection by preliminarily arranging conductive particles in the concave portion of the substrate having the concave portion formed therein, An adhesive layer is provided on the surface of the substrate on which the recesses are formed, and the conductive particles are transferred to the adhesive layer. According to this method, the conductive particles can be arranged in a separated state in a predetermined region in the thin film. Therefore, for example, by using a substrate having a pattern of concave portions corresponding to the pattern (circuit pattern) of the electrode to be connected to manufacture the adhesive film for circuit connection, it is possible to sufficiently control the amount of conductive particles in the adhesive film for circuit connection. location and number.

However, in the above method, in order to transfer the conductive particles to the adhesive layer, the adhesive layer needs to have appropriate fluidity. Therefore, in the adhesive film for circuit connection obtained by the above method, the resin constituting the adhesive layer flows at the time of connection, and the conductive particles also flow, thereby sometimes causing the conductive particles to pass from between the opposing circuit electrodes. to be excluded. In addition, it is also considered to suppress the flow of the conductive particles by curing the adhesive layer after transferring the conductive particles to the adhesive layer, but in this case, the resin existing between the electrodes and the conductive particles at the time of connection is not easily removed and it is easy to There is a problem that the connection resistance rises.

Therefore, the main object of the present invention is to provide a manufacturing method capable of improving the capture rate of the conductive particles between the opposing circuit electrodes while sufficiently controlling the position and number of the conductive particles, and sufficiently ensuring the conduction between the electrodes. The method of the adhesive film for circuit connection.

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

[1] A method for producing an adhesive film for circuit connection, comprising the steps of: preparing a substrate having a plurality of concave portions on the surface and disposing conductive particles on at least a part of the plurality of concave portions; A composition layer containing a photocurable component and a first thermosetting component is provided thereon, the conductive particles are transferred to the composition layer, and light is irradiated to the composition layer to form a plurality of conductive particles, the The cured product of the photocurable component and the first adhesive layer of the first thermosetting component; and the second adhesive layer containing the second thermosetting component is provided on one surface of the first adhesive layer.

[2] The method for producing an adhesive film for circuit connection according to [1], wherein The said photocurable component contains a radically polymerizable compound and a photoradical polymerization initiator, and the said 1st thermosetting component contains a cationically polymerizable compound and a thermal cationic polymerization initiator.

[3] The method for producing an adhesive film for circuit connection according to [2], wherein The said 1st thermosetting component contains the compound which has a cyclic ether group as the said cationically polymerizable compound.

[4] The method for producing an adhesive film for circuit connection according to [3], wherein The said 1st thermosetting component contains at least 1 sort(s) chosen from the group which consists of an oxetane compound and an alicyclic epoxy compound as the said cationically polymerizable compound.

[式（1）中，R ¹表示氫原子或甲基，X表示碳數1～3的烷二基。] [5] The method for producing an 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 radical polymerization sexual compounds. [Chemical formula 1]

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

[式（I）中，R ²、R ³及R ⁴分別獨立地表示氫原子、碳數1～20的烷基或包含芳香族系烴基之有機基團。] [6] The method for producing an 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. [Chemical formula 2]

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

[式（II）中，R ⁵及R ⁶分別獨立地表示氫原子、碳數1～20的烷基或者包含具有取代基或未經取代的芳香族系烴基之有機基團，R ⁷表示碳數1～6的烷基。] [化學式4]

[式（III）中，R ⁸及R ⁹分別獨立地表示氫原子、碳數1～20的烷基或者包含具有取代基或未經取代的芳香族系烴基之有機基團，R ¹⁰及R ¹¹分別獨立地表示碳數1～6的烷基。] [7] The method for producing an adhesive film for circuit connection according to any one of [2] to [6], wherein the first thermosetting component contains the following formula (II) or the following formula (III) ) represents a salt compound having a cation as the aforementioned thermal cationic polymerization initiator. [Chemical formula 3]

[In formula (II), R ⁵ and R ⁶ each independently represent a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an organic group containing a substituted or unsubstituted aromatic hydrocarbon group, and R ⁷ represents a carbon An alkyl group of numbers 1 to 6. ] [Chemical formula 4]

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

[8] The method for producing an adhesive film for circuit connection according to any one of [1] to [7], wherein The average particle diameter of the said conductive particle is 1-30 micrometers, and the C.V. value of the particle diameter of the said conductive particle 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 aforementioned conductive particles are solder particles.

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

[11] The method for producing an adhesive film for circuit connection according to [10], wherein The aforementioned solder particles are selected from the group consisting of 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 At least one of the group consisting of alloys.

[12] The method for producing an adhesive film for circuit connection according to any one of [9] to [11], wherein A part of the surface of the said solder particle has a flat part.

[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 portion to the diameter A of the solder particles satisfies the following formula. 0.01＜B/A＜1.0

[14] The method for producing an adhesive film for circuit connection according to any one of [1] to [13], wherein When a quadrilateral circumscribing the projected image of the conductive particle is formed from two pairs of parallel lines, the distance between the opposing sides is X and Y, and when Y<X, X and Y satisfy the following formula. 0.8＜Y/X≤1.0

[15] The method for producing 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, using a composition containing a photocurable component and a thermosetting component, the conductive particles are transferred to a layer (composition layer) made of the composition, and then the composition is photocured . Therefore, resin flow at the time of connection can be suppressed without impairing transferability. Therefore, according to the manufacturing method of the above-mentioned aspect, it is possible to obtain a circuit connection that can improve the capture rate of the conductive particles between the opposing circuit electrodes while sufficiently controlling the position and number of the conductive particles in the adhesive film for circuit connection. Use adhesive film. Moreover, in the manufacturing method of the said aspect, the conduction|electrical_connection between electrodes can be fully ensured. This is presumably because the thermosetting component can be contained in the photocured layer (the first adhesive layer) of the above-mentioned composition layer by using the photocurable component and the thermosetting component, and the photocurable component This layer imparts fluidity to the resin to such an extent that the conductive particles are not excluded during connection, so that the occurrence of problems such as an increase in connection resistance due to the resin existing between the electrodes and the conductive particles is not easily removed during connection can be suppressed.

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

[16] An adhesive film for circuit connection, comprising conductive particles, the adhesive film for circuit connection comprising: a first adhesive layer containing a plurality of the conductive particles, a cured product of a photocurable component, and a first thermosetting and a second adhesive layer, which is provided on the first adhesive layer and contains a second thermosetting component, and at least a part of the plurality of conductive particles is formed in a predetermined pattern in a plan view of the adhesive film for circuit connection They are arranged, and in the longitudinal section of the adhesive film for circuit connection, they are arranged laterally in a state where the adjacent conductive particles are separated from each other.

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

[17] A connection structure comprising: a first circuit member having a first electrode; a second circuit member having a second electrode; and a connection portion comprising the curing of the adhesive film for circuit connection described in [16] The first electrode and the second electrode are electrically connected to each other via the conductive particles, and the first circuit member and the second circuit member are bonded together.

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

[18] A method of manufacturing a connection structure, comprising the steps of: a surface of a first circuit member having a first electrode on which the first electrode is provided and a second circuit member having a second electrode having the first electrode provided thereon The adhesive film for circuit connection described in [16] is arranged between the surfaces of the two electrodes; and a laminate comprising the first circuit member, the adhesive film for circuit connection, and the second circuit member is placed on the side of the laminate. The first electrode and the second electrode are electrically connected to each other via the conductive particles by heating while being pressed in the thickness direction, and the first circuit member and the second circuit member are bonded together. [Inventive effect]

According to the present invention, it is possible to provide a circuit connection that can sufficiently control the position and number of conductive particles, improve the capture rate of conductive particles between opposing circuit electrodes, and sufficiently ensure continuity between the electrodes. The method of using the adhesive film.

Hereinafter, embodiments of the present invention will be described. However, the present invention is not limited to the following embodiments. In addition, as for the materials illustrated below, unless otherwise specified, one type may be used alone, or two or more types may be used in combination. The content of each component in the composition refers to the total amount of the plurality of substances present in the composition unless otherwise specified, when there are plural substances corresponding to each component in the composition. The numerical range shown using "-" shows the range which includes the numerical value described before and after "-" as a minimum value and a maximum value, respectively. In the numerical range described in stages in this specification, the upper limit value or the lower limit value of the numerical value range in a certain stage may be replaced with the upper limit value or the lower limit value of the numerical value range in another stage. Within the numerical range described in this specification, the upper limit value or the lower limit value of the numerical range can be replaced with the value shown in the Examples. In this specification, "(meth)acrylate" means at least one of acrylate and its 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 longitudinal section of an adhesive film for circuit connection according to an embodiment. The adhesive film 10A for circuit connection shown in FIG. 1 is a film-like adhesive (adhesive film) including a first adhesive layer 1, a plurality of conductive particles 4 and a cured photocurable component. The adhesive component 3 of the material and the first thermosetting component; and the second adhesive layer 2, which are provided on the first adhesive layer 1 and contain the second thermosetting component. In this specification, a "longitudinal cross section" means a cross section (a cross section in the thickness direction) substantially perpendicular to the main surface (for example, the main surface of the adhesive film 10A for circuit connection). In addition, a 1st thermosetting component and a 2nd thermosetting component mean the thermosetting component contained in a 1st adhesive bond layer and a 2nd adhesive bond layer, respectively.

At least a part of the plurality of conductive particles 4 is laterally arranged in a state in which adjacent conductive particles are separated from each other in the longitudinal section of the adhesive film 10A for circuit connection. In other words, the adhesive film 10A for circuit connection is composed of a central region 10a in which conductive particles 4 are separated from adjacent conductive particles in a longitudinal section and a central region 10a in which conductive particles 4 are formed in a horizontal row, and surface side regions 10b and 10c where conductive particles 4 do not exist. Here, the "horizontal direction" refers to a direction substantially parallel to the main surface of the adhesive film for circuit connection (the left-right direction in FIG. 1 ). The adjacent conductive particles are laterally arranged in a state of being separated from each other, and can be confirmed, for example, by observing the vertical cross section of the adhesive film for circuit connection with a scanning electron microscope or the like. In addition, in FIG. 1 , a part of the conductive particles 4 is exposed from the surface of the first adhesive layer 1 (for example, protruding to the side of the second adhesive layer 2 ), but the entire conductive particles 4 may be embedded in the first adhesive. In the layer 1 , the conductive particles 4 are not exposed from the surface of the first adhesive layer 1 .

2 and 3 are plan views schematically showing an example of arrangement of the conductive particles 4 in the adhesive film 10A for circuit connection. As shown in FIGS. 2 and 3 , at least a part of the plurality of conductive particles 4 is arranged in a predetermined pattern in a plan view of the adhesive film for circuit connection. In FIG. 2 , the conductive particles 4 are arranged at regular and substantially equal intervals in the entire area of the adhesive film for circuit connection 10A in a plan view of the adhesive film for circuit connection. However, as shown in FIG. 3 , for example, The conductive particles 4 may be arranged so as to regularly form regions 10d where a plurality of conductive particles 4 are regularly arranged and a region 10e where the conductive particles 4 do not exist in a plan view of the adhesive film for circuit connection. The position and number of the conductive particles 4 can be set according to, for example, the shape, size, and pattern of the electrodes to be connected. At least a part of a plurality of conductive particles are arranged in a predetermined pattern, for example, can be confirmed by observing the adhesive film for circuit connection from above the main surface of the adhesive film for circuit connection using an electron microscope or the like.

(1st adhesive layer) The first adhesive layer 1 contains the conductive particles 4 (hereinafter, sometimes referred to as "(A) component".), a photocurable component (hereinafter, sometimes referred to as "(B) component".) cured product and the first 1 Thermosetting component (Hereinafter, it may be referred to as "(C) component".). The hardened|cured material of (B) component may be hardened|cured fully hardened|cured of (B) component, and what hardened a part of (B) component may be sufficient as it. The component (C) is a component that can flow during connection, and is, for example, an uncured curable component (for example, a resin component). Components other than the conductive particles 4 constituting the first adhesive layer 1 are, for example, components that do not have conductivity (eg, insulating resin components).

[(A) Component: Conductive Particles] The component (A) is not particularly limited as long as it is a particle having conductivity, and may be metal particles composed of metals such as Au, Ag, Pd, Ni, Cu, and solder, and conductive carbon composed of conductive carbon. particles, etc. The component (A) may be a coated conductive particle having a core containing a non-conductive glass, ceramic, plastic (polystyrene, etc.), or the like, and a coating layer containing the above-mentioned metal or conductive carbon and coating the core. (A) Component can be used individually by 1 type of conductive particle or in combination of 2 or more types of conductive particles.

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

When the metal particle which consists of a hot-melt metal is used as (A) component, the connection between electrodes tends to be firmer. This tendency is remarkable when using solder particle|grains as (A) component.

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 having 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, etc. can be used. Specific examples of these tin alloys include the following examples. •In-Sn (In52 mass%, Sn48 mass%, melting point 118°C) •In-Sn-Ag (In20 mass %, Sn 77.2 mass %, Ag 2.8 mass %, melting point 175°C) •Sn-Bi (Sn43 mass%, Bi57 mass%, melting point 138℃) •Sn-Bi-Ag (Sn42 mass%, Bi57 mass%, Ag1 mass%, melting point 139℃) •Sn-Ag-Cu (96.5 mass % Sn, 3 mass % Ag, 0.5 mass % Cu, melting point 217°C) •Sn-Cu (99.3 mass % Sn, 0.7 mass % Cu, melting point 227°C) •Sn-Au (Sn 21.0 mass %, Au 79.0 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 mass%, Bi33.7 mass%, melting point 72°C) •In-Bi (In33.0 mass%, Bi67.0 mass%, melting point 109°C) •In-Ag (In97.0 mass %, Ag 3.0 mass %, melting point 145°C) In addition, the above-mentioned indium alloys containing tin are classified as tin alloys.

From the viewpoint of obtaining higher reliability in a high temperature and high humidity test and a thermal shock test, the solder particles may contain a material selected from the group consisting of In-Bi alloy, In-Sn alloy, In-Sn-Ag alloy, Sn-Au At least one of alloys, Sn-Bi alloys, Sn-Bi-Ag alloys, Sn-Ag-Cu alloys, and Sn-Cu alloys.

The above-mentioned tin alloy or indium alloy can be selected according to the application of the solder particles (temperature at the time of use) and the like. For example, when the solder particles are used for welding at low temperature, when an In—Sn alloy or a Sn—Bi alloy is used, the welding can be performed at a temperature of 150° C. or lower. When a material with a high melting point such as Sn-Ag-Cu alloy and 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 can be 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 mass %, and may be 0.1 to 5 mass % or 0.2 to 3 mass %. When the Cu content is 0.05 mass % or more, it is easy to realize better solder connection reliability. In addition, when the Cu content is 10 mass % or less, the melting point is low, and solder particles having excellent wettability are likely to be obtained. As a result, the connection reliability of the joint portion by the solder particles is likely to be good.

The Ag content of the solder particles is, for example, 0.05 to 10 mass %, and may be 0.1 to 5 mass % or 0.2 to 3 mass %. When the Ag content is 0.05 mass % or more, it is easy to realize better solder connection reliability. In addition, when the Ag content is 10 mass % or less, the melting point is low, and solder particles with excellent wettability are likely to be obtained. As a result, the connection reliability of the joint portion by the solder particles is likely to be good.

A part of the surface of the solder particle may have a flat portion. When such solder particles are used, a large contact area can be secured between the flat portion and the electrode by contacting the flat portion of the solder particle with the electrode. In addition, when connecting an electrode formed of a material that is easily wetted and spread by solder and an electrode formed of a material that is not easily wetted and spread by solder, it is possible to adjust the flat surface portion of the solder particles on the electrode side of the latter, so that the two can be appropriately performed. connection between electrodes. In the solder particles, the surfaces other than the above-mentioned flat portion may be spherical crowns. That is, the solder particles may have a flat portion and a spherically crowned curved portion. Specifically, the solder particles may have a shape in which a flat portion with a diameter B is formed on a part of the surface of a ball having a diameter A. In the case of using such solder particles, it is easy to obtain more excellent conduction reliability and insulation reliability.

In the case where the solder particles have a shape in which a plane portion with a diameter B is formed on a part of the surface of a ball having a diameter A, the diameter B of the plane portion is the same as the The ratio (B/A) of the diameters A of the solder particles may be, for example, more than 0.01 and less than 1.0 (0.01<B/A<1.0), or may be 0.1 to 0.9. The diameter A of the solder particles and the diameter B of the flat portion can be observed, for example, with a scanning electron microscope or the like. Specifically, arbitrary solder particles are observed with a scanning electron microscope, and an image is captured. From the obtained image, the diameter A of the solder particle and the diameter B of the flat portion are measured, and the B/A of the particle is determined. This operation was performed for 300 solder particles, and the average value was calculated as the B/A of the solder particles.

In the case of making a quadrilateral circumscribing the projected image of the conductive particle by two pairs of parallel lines, if the distance between the opposite sides is taken as X and Y respectively (where Y<X), then the ratio of Y to X ( Y/X) may exceed 0.8 and be 1.0 or less (0.8<Y/X≤1.0). Such conductive particles can be called particles closer to spheres. When the conductive particles have a shape close to a sphere, the solder particles tend to be easily accommodated in the recessed portions of the base in the manufacturing method described later. In addition, in the case where solder particles are also used as conductive particles, since the solder particles have a shape close to a sphere, when a plurality of electrodes facing each other are electrically connected via solder, it is difficult for the solder particles to contact the electrodes. Unevenness occurs, and a stable connection tends to be obtained. The ratio of Y to X (Y/X) may exceed 0.8 and less than 1.0 (0.8<Y/X<1.0), and may be 0.81 to 0.99. The projection image of a conductive particle can be obtained, for example, by observing arbitrary conductive particles with a scanning electron microscope. To obtain Y/X, two pairs of parallel lines are drawn on the obtained projected image, one pair of parallel lines is arranged at the position where the distance between the parallel lines is the smallest, and the other pair of parallel lines is arranged at the position where the distance between the parallel lines is the largest. This operation was performed for 300 conductive particles, and the average value of Y/X was calculated, which was taken as the Y/X of the conductive particles.

The component (A) may be an insulating-coated conductive particle including the above-mentioned metal particles, conductive carbon particles, or coated conductive particles, and an insulating layer containing an insulating material such as a resin and covering the surface of the particles. If the component (A) is the insulating-coated conductive particle, even when the content of the component (A) is large, since the insulating layer is provided on the surface of the particle, it is possible to suppress the short circuit caused by the contact between the components (A). occurs, and the insulation between adjacent electrode circuits can also be improved.

The average particle diameter of the component (A) may be 1 μm or more, 2 μm or more, or 4 μm or more from the viewpoint of easily obtaining excellent electrical conductivity. The average particle diameter of the component (A) may be 30 μm or less, 25 μm or less, or 20 μm or less, from the viewpoint of easily obtaining better connection reliability with micro-sized electrodes. From these viewpoints, the average particle diameter of the component (A) may be 1 to 30 μm, 2 to 25 μm, or 4 to 20 μm.

The average particle diameter of the component (A) can be measured 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 mass measurement method, or the like can be used. Furthermore, a method of measuring particle size based on an image obtained by an optical microscope, an electron microscope, or the like can be used. As a specific apparatus, a flow particle image analyzer, a Microtrac, a Coulter counter, etc. are mentioned. In addition, the particle diameter of the non-spherical (A) component may be the diameter of a circle circumscribing the conductive particles in the SEM image.

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

The C.V. value of the particle diameter of the component (A) was calculated by multiplying the value obtained by dividing the standard deviation of the particle diameter of the conductive particles by the average particle diameter by 100. The standard deviation of the particle diameter of the conductive particles was measured by the same method as the above-mentioned method of measuring the average particle diameter of the conductive particles.

The component (A) may be conductive particles having an average particle diameter of 1 to 30 μm and a C.V. value of the particle diameter 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 anisotropic conductive materials with high electrical conductivity and high insulation reliability.

From the viewpoint of being able to further improve the conductivity, the content of the component (A) may be, for example, 1 mass % or more, 5 mass % or more, or 10 mass % or more based on the total mass of the first adhesive layer. From the viewpoint of easily suppressing short circuits, the content of the component (A) may be, for example, 80 mass % or less, 70 mass % or less, or 60 mass % or less based on the total mass of the first adhesive layer. From these viewpoints, the content of the component (A) may be, for example, 1 to 80 mass %, 5 to 70 mass %, or 10 to 60 mass % based on the total mass of the first adhesive layer.

From the viewpoint of obtaining stable connection resistance, the particle density of the component (A) in the first adhesive layer 1 may be 100 particles/mm ² or more, 1000 particles/mm ² or more, 3000 particles/mm ² or more, or 5000/ ^mm2 or more. From the viewpoint of improving the insulating properties between adjacent electrodes, the particle density of the component (A) in the first adhesive layer 1 may be 100,000 particles/mm ² or less, 70,000 particles/mm ² or less, and 50,000 particles/ mm ² or less or 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 more excellent connection resistance. The (B) component may contain, for example, a radically polymerizable compound (hereinafter, sometimes referred to as "(B1) component") and a photoradical polymerization initiator (hereinafter, sometimes referred to as "(B2) component".) . (B) component may be a component consisting of (B1) component and (B2) component.

(B1) component: radically polymerizable compound (B1) component is a compound (radical polymerizable compound) which has a polymerizable group (radical polymerizable group) which reacts with a radical. As a radical polymerizable group, a (meth)acryloyl group, a vinyl group, an allyl group, a styryl group, an alkenyl group, an alkenyl group, a maleimide group, etc. are mentioned, for example. After the polymerization, the desired melt viscosity is easily obtained, the effect of reducing the connection resistance is further improved, and the connection reliability is more excellent, the number (functional group) of the radically polymerizable group that the component (B1) has can be Two or more, from the viewpoint of suppressing curing shrinkage during polymerization, may be 10 or less. Furthermore, in order to maintain the balance between the crosslinking density and curing shrinkage, in addition to the compound having the radical polymerizable group number within the above range, a compound having the radical polymerizable group number outside the above range may be used.

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

Examples of polyfunctional (meth)acrylates include ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, and triethylene glycol di(meth)acrylate. , tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate ) acrylate, tetrapropylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, ethoxylated polypropylene glycol di(meth)acrylate, 1,3-butanediol di(meth)acrylate Acrylates, 1,4-butanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 3-methyl-1,5-pentanediol di(meth)acrylate, 1,6-Hexanediol di(meth)acrylate, 2-butyl-2-ethyl-1,3-propanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate Acrylates, 1,10-decanediol di(meth)acrylate, glycerol di(meth)acrylate, tricyclodecanedimethanol (meth)acrylate, ethoxylated 2-methyl- 1,3-Propanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, ethoxylated trimethylolpropane tri(meth)acrylate, propoxylated trimethylol Propane tri(meth)acrylate, ethoxylated propoxylated trimethylolpropane tri(meth)acrylate, neotaerythritol tri(meth)acrylate, ethoxylated neopentyltetrakis Alcohol tri(meth)acrylate, propoxylated neotaerythritol tri(meth)acrylate, ethoxylated propoxylated neotaerythritol tri(meth)acrylate, neotaerythritol tetra (Meth)acrylates, ethoxylated neotaerythritol tetra(meth)acrylate, propoxylated neotaerythritol tetra(meth)acrylate, ethoxylated propoxylated neopentyltetrakis Aliphatic (meth)acrylates such as alcohol tetra(meth)acrylate, ditrimethylolpropane tetraacrylate, dipivalerythritol hexa(meth)acrylate; ethoxylated bisphenol A-type dimethacrylate (Meth)acrylate, propoxylated bisphenol A di(meth)acrylate, ethoxylated propoxylated bisphenol A 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 type di(meth)acrylates (for example, 9,9-bis[4-(2-propenyloxyethoxy)phenyl]perylene), propoxylated perylene di(meth)acrylates, Aromatic (meth)acrylates such as ethoxylated propoxylated phenyl-type di(meth)acrylates; bisphenol-type epoxy (meth)acrylates, novolak-type epoxy (meth)acrylates , Aromatic epoxy (meth) acrylate such as cresol novolac epoxy (meth) acrylate; Cyanurate (meth)acrylate, etc.

In terms of both the effect of reducing the connection resistance and the suppression of particle flow, the content of the polyfunctional (bifunctional or more) (meth)acrylate based on the total mass of the component (B1) can be, for example, 40 to 100. mass %, 50 to 100 mass %, or 60 to 100 mass %.

The (B1) component may contain a monofunctional (meth)acrylate in addition to the polyfunctional (bifunctional or more) (meth)acrylate. As monofunctional (meth)acrylate, for example, (meth)acrylic acid; methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, (meth)acrylate Isobutyl acrylate, tertiary butyl (meth)acrylate, butoxyethyl (meth)acrylate, isoamyl (meth)acrylate, hexyl (meth)acrylate, 2-ethyl (meth)acrylate Hexyl (meth)acrylate, heptyl (meth)acrylate, octylheptyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate 2-(meth)acrylate hydroxyethyl, (meth)acrylate ) 2-hydroxypropyl acrylate, 3-chloro-2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, ethyl acetate Oxypolyethylene glycol (meth)acrylate, methoxypolypropylene glycol (meth)acrylate, ethoxypolypropylene glycol (meth)acrylate, mono(2-(meth)acryloyloxyethyl) ) Aliphatic (meth)acrylates such as succinate; benzyl (meth)acrylate, phenyl (meth)acrylate, o-biphenyl (meth)acrylate, naphthyl 1-(meth)acrylate, Naphthyl 2-(meth)acrylate, Phenoxyethyl (meth)acrylate, p-Cumylphenoxyethyl (meth)acrylate, o-phenylphenoxyethyl (meth)acrylate, 1-naphthoxyethyl (meth)acrylate, 2-naphthoxyethyl (meth)acrylate, phenoxy polyethylene glycol (meth)acrylate, nonylphenoxy polyethylene glycol ( Meth)acrylate, phenoxy polypropylene glycol (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, 2-hydroxy-3-(o-phenylphenoxy)propane (meth)acrylate, 2-hydroxy-3-(1-naphthyloxy)propyl (meth)acrylate, 2-hydroxy-3-(2-naphthyloxy)propyl (meth)acrylate Aromatic (meth)acrylates such as esters and bisphenol A epoxy (meth)acrylates; (meth)acrylates with epoxy groups such as glycidyl (meth)acrylate, 3,4- (Meth)acrylate having an alicyclic epoxy group such as epoxycyclohexylmethyl (meth)acrylate, (3-ethyloxetan-3-yl)methyl (meth)acrylic acid (Meth)acrylate etc. which have an oxetanyl group, such as an ester.

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

(B) The hardened|cured material of a component may have the polymerizable group which reacts by the thing other than a radical, for example. The polymerizable group that reacts by something other than a radical may be, for example, a cationic polymerizable group that reacts by a cation. Examples of cationically polymerizable groups include epoxy groups such as glycidyl groups, alicyclic epoxy groups such as epoxycyclohexylmethyl groups, and oxetane groups such as ethyloxetanylmethyl groups. Base et al. The cured product of the component (B) having a polymerizable group that reacts by something other than a radical can be obtained by using, for example, a (meth)acrylate having an epoxy group, a (methyl) having an alicyclic epoxy group. ) The (meth)acrylate which has a polymerizable group which reacts by a thing other than a radical, such as an acrylate and the (meth)acrylate which has an oxetane group, is introduce|transduced as (B) component.

As a (meth)acrylate having a polymerizable group that reacts by something other than a radical, the radically polymerizable compound and the thermosetting component to be described later are cross-linked to form a stronger connection portion at the time of connection From a viewpoint, the compound represented by following formula (1) can be used. [Chemical formula 5]

In formula (1), R ¹ represents a hydrogen atom or a methyl group, and X represents an alkanediyl group having 1 to 3 carbon atoms. As a C1-C3 alkanediyl group, a methylene group, an ethylidene group, a propylidene group, etc. are mentioned, for example. As a specific example of the compound represented by the said formula (1), 3, 4- epoxycyclohexyl methyl (meth)acrylate is mentioned.

From the viewpoint of suppressing curing shrinkage during polymerization, a radically polymerizable compound (such as (meth)acrylate) having a polymerizable group that reacts by means of other than radicals can be combined with Radical polymerizable compounds (such as (meth)acrylates) of polymerizable groups other than those that react can be used. From the viewpoint of improving reliability, the mass ratio of the radically polymerizable compound having a polymerizable group that reacts by means other than radicals relative to the total mass of the component (B1) (having radicals other than radicals) The mass of the radically polymerizable compound of the polymerizable group to be reacted (charge amount)/(B1) the total mass of the component (charge amount)) may be, for example, 0 or more, 0.1 or more, 0.2 or more, or 0.3 or more, and may be 0.7 or less, 0.6 or less, 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 curing shrinkage during polymerization, (meth)acrylates having a polymerizable group that reacts with other than radicals are compared to those that do not have a polymerizable group that reacts with other than radicals. The mass ratio of the (meth)acrylate can be within the above range.

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

(B2) Component: photo-radical polymerization initiator The component (B2) is obtained by irradiating light with a wavelength within a range of 150 to 750 nm, preferably with light with a wavelength within a range of 254 to 405 nm, and more preferably with light with a wavelength of 365 nm (for example, ultraviolet light). ) to generate a free radical photopolymerization initiator (photolatent free radical generator). (B2) component may be used individually by 1 type, and may be used in combination of a plurality of types.

The component (B2) is decomposed by light to generate free radicals. That is, (B2) component is a compound which generates a radical by external application of light energy. (B2) Component may have oxime ester structure, bisimidazole structure, acridine structure, α-aminoalkylphenone structure, aminodiphenylketone structure, N-phenylglycine structure, acylphosphine oxide Structure, benzyl dimethyl ketal structure, α-hydroxyalkyl phenone structure and other structures. (B2) component may be used individually by 1 type, and may be used in combination of a plurality of types.

The (B2) component may be a compound having an oxime ester structure from the viewpoints of further suppressing the flow of conductive particles, further increasing the capture rate, and further suppressing peeling after connection and further suppressing the rise in connection resistance. From the same viewpoint, the compound having an oxime ester structure may be a compound represented by the following formula (I). [Chemical formula 6]

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

Specific examples of the compound having an oxime ester structure include 1-phenyl-1,2-butanedione-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-Benzyl oxime, 1,3-diphenylglycerol-2-(o-ethoxycarbonyl) oxime, 1-phenyl-3-ethoxy glycerol-2-(o-benzyl glycerol) base) oxime, 1,2-octanedione, 1-[4-(phenylthio)phenyl-,2-(o-benzyl oxime)], ethanone, 1-[9-ethyl-6- (2-methylbenzyl)-9H-carbazol-3-yl]-, 1-(o-acetoxime) and the like. When such a highly active oxime ester type photo-radical polymerization initiator is used, even when the compounding quantity of (B1) component is small, bridge|crosslinking can fully advance.

From the viewpoint of suppressing the flow of the conductive particles, the content of the component (B2) may be, for example, 0.1 to 10 parts by mass, 0.3 to 7 parts by mass, or 0.5 to 5 parts by mass relative to 100 parts by mass of the (B1) component.

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

[(C)component: thermosetting component] The component (C) is not particularly limited as long as it is a component (for example, a resin component) that is cured by heat. However, when the component (B) is a component having radical curability, the storage stability and the like are required. From the viewpoint of (C) component, the component which does not have radical curability may be sufficient. In the case where the component (B) is a component having radical curability, and the component (C) is also a component having radical curability, there is a possibility that the radicals remaining in the first adhesive layer may be caused by the radicals during storage. The curing of the thermosetting component is performed. Examples of components not having radical curability include components having cationic curability (eg, cationically polymerizable compounds and thermal cationic polymerization initiators) and components having anionic curability (anionic polymerizable compounds and thermal anionic polymerization initiators) starter).

From the viewpoint of being more excellent in connection resistance, the component (C) may be a component having cationic curability, for example, may contain a cationically polymerizable compound (hereinafter, sometimes referred to as "component (C1)") and thermal cationic polymerization. Starter (Hereinafter, sometimes referred to as "(C2) component".). The (C) component may be a component consisting only of the (C1) component and the (C2) component.

(C1) component: cationic polymerizable compound The (C1) component is a compound that is crosslinked by the reaction of the (C2) component with heat. In addition, (C1) component means the compound which does not have a radically polymerizable group, (C1) component is not included in (B1) component. As for the (C1) component, one type may be used alone, or a plurality of types may be used in combination.

The (C1) component may be a compound having a cyclic ether group from the viewpoint that the effect of reducing the connection resistance is further improved and the connection reliability is more excellent. In the compound having a cyclic ether group, when at least one selected from the group consisting of an oxetane compound and an alicyclic epoxy compound is used, the effect of reducing the connection resistance tends to be further enhanced. From the viewpoint of easily obtaining a desired melt viscosity, the component (C1) may contain both at least one oxetane compound and at least one alicyclic epoxy compound.

The oxetane compound as the component (C1) can be used without particular limitation as long as it has an oxetane group and does not have a radical 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 INDUSTRIES, LTD.), OXSQ, OXT-121, OXT-221, OXT-101, OXT-212 (trade name, manufactured by TOAGOSEI CO., LTD.), etc. One of these compounds may be used alone, or a plurality of them may be used in combination.

The alicyclic epoxy compound of the component (C1) can be used without particular limitation as long as it has an alicyclic epoxy group (eg, epoxycyclohexyl group) and does not have a radically polymerizable group. Examples of commercially available alicyclic epoxy compounds include CELLOXIDE8010 (trade name, bis-7-oxabicyclo[4.1.0]heptane, manufactured by Daicel Corporation), for example, EHPE3150, EHPE3150CE, and CELLOXIDE2021P , CELLOXIDE2081 (trade name, manufactured by Daicel Corporation), etc. One of these compounds may be used alone, or a plurality of them may be used in combination. As the component (C1), epoxy compounds having aromatic hydrocarbon groups such as bisphenol A epoxy resins and bisphenol F epoxy resins (eg, trade names "jER1010", "YL983U" manufactured by Mitsubishi Chemical Corporation) can also be used "Wait). From the viewpoint that the effect of reducing the connection resistance is further improved and the connection reliability is more excellent, the epoxy compound having an aromatic hydrocarbon group can be used in combination with an alicyclic epoxy compound.

(C2) Component: Thermal Cationic Polymerization Initiator The (C2) component is a thermal polymerization initiator (thermal latent cation generator) that starts 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) includes, for example, BF ₄ ^- , BR ₄ ^- (R represents a phenyl group substituted with two or more fluorine atoms or two or more trifluoromethyl groups.), PF ₆ ^- , and SbF Sulfonium salts, phosphonium salts, ammonium salts, diazonium salts, iodonium salts, aniline salts, pyridinium salts and other onium salts of anions such as ₆ ^- and AsF ₆ ^- . These may be used individually by 1 type, and may be used in combination of a plurality of types.

From the viewpoint of rapid curability, the component (C2) may be, for example, a salt compound having an anion containing boron as a constituent element. Examples of such salt compounds include salt compounds having BF ₄ ^- or BR ₄ ^- (R represents a phenyl group substituted with two or more fluorine atoms or two or more trifluoromethyl groups). The anion containing boron as a constituent element may be BR ₄ ⁻ , and more specifically, tetrakis(pentafluorophenyl)borate.

[化學式8]

From the viewpoint of storage stability, the component (C2) may be a salt compound having a cation represented by the following formula (II) or the following formula (III). [Chemical formula 7]

[Chemical formula 8]

In formula (II), R ⁵ and R ⁶ each independently represent a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an organic group containing a substituted or unsubstituted aromatic hydrocarbon group, and R ⁷ represents a carbon number 1-6 alkyl groups.

The salt compound having a cation represented by formula (II) may be an aromatic sulfonium salt compound (aromatic sulfonium salt type thermal acid generator) from the viewpoint of having both storage stability and low-temperature activity. That is, at least one of R ⁵ and R ⁶ in formula (II) may be an organic group including a substituted or unsubstituted aromatic hydrocarbon group. The anion in the salt compound having a cation represented by formula (II) may be an anion containing antimony as a constituent element, and for example, may be 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 INDUSTRY CO., LTD., SI-60 main agent) etc.

In formula (III), R ⁸ and R ⁹ each independently represent a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an organic group containing a substituted or unsubstituted aromatic hydrocarbon group, R ¹⁰ and R ¹¹ Each independently represents an alkyl group having 1 to 6 carbon atoms.

The salt compound having a cation (quaternary ammonium salt type thermal acid generator) represented by the formula (III) has resistance to a substance that may cause curing inhibition to cationic curing, and therefore can be, for example, an aniline salt compound. That is, at least one of R ⁸ and R ⁹ in formula (III) may be an organic group including a substituted or unsubstituted aromatic hydrocarbon group. As an aniline salt compound, N,N- dialkylaniline salts, such as N,N- dimethylaniline salt and N,N- diethylaniline salt, etc. are mentioned, for example. The anion in the salt compound having a cation represented by the formula (III) may be an anion containing boron as a constituent element, for example, may be tetrakis(pentafluorophenyl)borate.

The compound having a cation represented by the formula (III) may be an aniline salt having an anion containing boron as a constituent element. As a commercial item of such a salt compound, CXC-1821 (trade name, manufactured by King Industries, Inc.) etc. are mentioned, for example.

From the viewpoint of securing the formability and curability of the adhesive film for forming the first adhesive layer, the content of the component (C2) may be, for example, 0.1 to 20 parts by mass relative to 100 parts by mass of the component (C1). 1-18 mass parts, 3-15 mass parts, or 5-12 mass parts.

From the viewpoint of securing the curability of the adhesive film for forming the first adhesive layer, the amount of the component (C) is 100 parts by mass of the total amount of components other than the component (A) in the first adhesive layer. The content 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. From the viewpoint of securing the formability of the adhesive film for forming the first adhesive layer, the amount of the component (C) relative to 100 parts by mass of the total amount of components other than the The content may be, for example, 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. From these viewpoints, the content of the component (C) can be, 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 components other than the (A) component in the first adhesive layer. , 15 to 50 parts by mass or 20 to 40 parts by mass. Moreover, content of (C)component in a composition or a composition layer (the basis of the total mass of a composition or a composition layer) may be the same as the said range.

[other ingredients] The first adhesive layer 1 may contain other components in addition to the cured product of the (A) component and the (B) component and the (C) component. As other components, for example, thermoplastic resins (hereinafter, sometimes referred to as "(D) components"), coupling agents (hereinafter, sometimes referred to as "(E) components"), and fillers (hereinafter, may be referred to as "(E) components".) Sometimes referred to as "(F)ingredients".) etc.

As (D)component, a phenoxy resin, a polyester resin, a polyamide resin, a polyurethane resin, a polyester urethane resin, an acrylic rubber, an epoxy resin (solid at 25 degreeC) etc. are mentioned, for example. These may be used individually by 1 type, and may be used in combination of a plurality of types. When the composition containing the (B) component and the (C) component further contains the (D) component, the composition layer (further, the first adhesive layer 1 ) can be easily formed from the composition. As said phenoxy resin, a phenoxy resin of a phenoxy resin, a bisphenol A/bisphenol F copolymerization type phenoxy resin, etc. are mentioned, for example.

The weight average molecular weight (Mw) of the component (D) may be, for example, 5,000 to 200,000, 10,000 to 100,000, 20,000 to 80,000, or 40,000 to 60,000, from the viewpoint of resin repulsion at the time of mounting. In addition, Mw means a value measured by gel permeation chromatography (GPC) and converted using a sizing line based on standard polystyrene.

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

As the component (E), for example, a silane coupling agent (γ-glycidoxypropyltrimethyl) having an organic functional group such as a (meth)acryloyl group, a mercapto group, an amino group, an imidazole group and an epoxy group can be mentioned. oxysilane, etc.), silane compounds such as tetraalkoxysilane, tetraalkoxytitanate derivatives, polydialkyltitanate derivatives, and the like. These may be used individually by 1 type, and may be used in combination of a plurality of types. The adhesiveness can be further improved by containing the (E) component in the first adhesive layer 1 . The (E) component may be, for example, a silane coupling agent.

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

As (F) component, a non-conductive filler (for example, non-conductive particle) is mentioned, for example. 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, titanium oxide 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, acryl-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 components other than the component (A) in the first adhesive layer. In addition, the content of the (F) component in the composition for forming the first adhesive layer or the composition layer (based on the total mass of the composition or the composition layer) may be the same as the above-mentioned range.

The first adhesive layer 1 may contain other additives such as softeners, accelerators, deterioration inhibitors, colorants, flame retardants, and thixotropic viscosity reducers as other components. The content of 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 components other than the (A) component in the first adhesive layer. In addition, the composition for forming the first adhesive layer or the content of 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-mentioned range.

The thickness d1 of the first adhesive layer 1 may be, 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 when the adhesive film for circuit connection is produced. The thickness d1 of the first adhesive layer 1 may be, 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 during connection. 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. In addition, 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, protrudes to the side of the second adhesive layer 2 ), the conductive particles 4 are removed from the surface of the first adhesive layer 1 . The distance from the surface 1a on the opposite side to the second adhesive layer 2 to the boundary S between the first adhesive layer 1 and the second adhesive layer 2 at the separated portion of the adjacent conductive particles 4 and 4 (see Fig. The distance represented by d1 in 1 ) is the thickness of the first adhesive layer 1 , and the exposed portion of the conductive particles 4 is not included in the thickness of the first adhesive layer 1 .

The thickness d1 of the first adhesive layer 1 is obtained, for example, by sandwiching an adhesive film between two glasses (thickness: about 1 mm), and using bisphenol A epoxy resin (trade name: jER811, Mitsubishi) Chemical Corporation) 100 g and a curing agent (trade name: Epomount curing agent, manufactured by Refine Tec Ltd.) 10 g of a resin composition after injection molding, cross-section grinding was performed using a grinder, and a scanning electron microscope (SEM, trade name) was used. : SE-8020, manufactured by Hitachi High-Tech Science Corporation) was measured.

<Second adhesive layer> The second adhesive layer 2 is, for example, an insulating adhesive layer composed of a non-conductive component (insulating resin component). The second adhesive layer 2 contains at least the (C) component.

Details (types, combinations, etc.) of 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 the same as the details of the components contained in the (C) component (that is, the first thermosetting component) in the first adhesive layer 1 , so detailed descriptions are omitted here. The second thermosetting component may be the same as or different from the first thermosetting component.

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

The second adhesive layer 2 may further contain other components (component (D), component (E), component (F), other additives, and the like) in the first adhesive layer 1 . The preferable aspect of the other components is the same as the preferable aspect of the first adhesive layer 1 .

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

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

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

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

The thickness d2 of the second adhesive layer 2 can 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 may be, for example, 2 μm or more, 5 μm or more, or 10 μm or more, from the viewpoint that the space between the electrodes can be sufficiently filled to seal the electrodes and better connection reliability can be obtained. 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. In addition, 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, protrudes toward the second adhesive layer 2 side), the conductive particles 4 are removed from the surface of the second adhesive layer 2 . The distance from the surface 2a on the side opposite to the first adhesive layer 1 to the boundary S between the first adhesive layer 1 and the second adhesive layer 2 at the separated portion of the adjacent conductive particles 4 and 4 (see Fig. The distance represented by d2 in 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 of measuring the thickness d1 of the first adhesive layer 1 described above.

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

The adhesive film for circuit connection 10A is an adhesive film for circuit connection. The adhesive film 10A for circuit connection may or may not have anisotropic conductivity. That is, the adhesive film for circuit connection may be an anisotropically conductive adhesive film, or may be a non-anisotropically conductive (for example, isotropically conductive) adhesive film. The adhesive film 10A for circuit connection is arranged between the surface of the first circuit member having the first electrode on which the first electrode is provided and the surface of the second circuit member having the second electrode on which the second electrode is provided, and It can be used to heat the laminate including the first circuit member, the adhesive film 10A for circuit connection, and the second circuit member in a state where the laminate is pressed in the thickness direction of the laminate, whereby the first electrode and the second electrode are heated. The electrodes are electrically connected to each other via the conductive particles (or the molten solidified product of the conductive particles), and the first circuit member and the second circuit member are bonded to each other. In addition, the above-mentioned "anisotropic conductivity" means conduction in the pressing direction and maintaining insulation in the non-pressing direction.

According to the adhesive film 10A for circuit connection, the heat-curable component ensures the repulsion of the resin during the connection, and the cured product of the photocurable component suppresses the fluidity of the conductive particles during the connection, so that the connection quality can be improved. Capture rate of conductive particles between electrodes. Therefore, according to the adhesive film 10A for circuit connection, it is possible to obtain a connected structure with little occurrence of short circuits and excellent conductivity between electrodes.

As mentioned above, although the adhesive agent film for circuit connection which concerns on one Embodiment was demonstrated, this invention is not limited to the said embodiment.

For example, like the adhesive film for circuit connection 10B shown in FIG. 4 , the adhesive film for circuit connection may have the component (C) on the opposite side of the first adhesive layer 1 to the second adhesive layer 2 . The third adhesive layer 5 of (thermosetting component). The third adhesive layer 5 is, for example, an insulating adhesive layer composed of a non-conductive component (insulating resin component). The circuit connection adhesive film 10B has the same structure as the circuit connection adhesive film 10A except that the third adhesive layer 5 is laminated.

The details of the component (C) (hereinafter, also referred to as "third thermosetting component") contained in the third adhesive layer 5 are the same as those of the above-mentioned thermosetting component. For example, the third thermosetting component may contain the (C1) component (that is, the cationically polymerizable compound) and the (C2) component (that is, the thermal cationic polymerization initiator). The components (C1) and (C2) used in the third thermosetting component are the same as the components (C1) and (C2) used in the first thermosetting component, so detailed descriptions are omitted here. 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.

From the viewpoint of imparting good transferability and peeling resistance, the content of the component (C) may be, for example, 5 mass % or more, 10 mass % or more, or 15 mass % based on the total mass of the third adhesive layer. or more or 20% by mass or more. From the viewpoint of imparting good half-cut properties and blocking resistance (resin bleed-out of the reel), the content of the component (C) may be, for example, 70 mass % or less and 60 mass % based on the total mass of the third adhesive layer. % or less, 50 mass % or less, or 40 mass % or less. From these viewpoints, the content of the component (C) may be, for example, 5 to 70 mass %, 10 to 60 mass %, 15 to 50 mass %, or 20 to 40 mass % based on the total mass of the third adhesive layer. %.

The third adhesive layer 5 may contain other components in the first adhesive layer 1 . The preferable aspect of the other components is the same as the preferable aspect of the first adhesive layer 1 .

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

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

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

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

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

When the adhesive film for circuit connection has layers other than the first adhesive layer and the second adhesive layer (for example, the third adhesive layer), the thickness of the adhesive film for circuit connection (constituting the adhesive film for circuit connection) The sum of the thicknesses of all layers of the adhesive film) may be the same as the preferred range of the thickness of the above-mentioned adhesive film 10A for circuit connection.

<Manufacturing method of adhesive film for circuit connection> The method for producing an adhesive film for circuit connection includes the steps of: preparing a substrate having a plurality of concave portions on the surface and arranging conductive particles on at least a part of the plurality of concave portions (preparation step); A composition layer containing a photocurable component and a first thermosetting component is arranged on the surface), and the conductive particles are transferred to the composition layer (transfer step); The conductive particle, the cured product of the photocurable component, and the first adhesive layer of the first thermosetting component (light irradiation step); and the first adhesive layer containing the second thermosetting component is provided on one surface of the first adhesive layer. 2 Adhesive layer (lamination step).

Hereinafter, the manufacturing method of the adhesive film 10A for a circuit connection mentioned above is illustrated, referring FIG. 5-FIG. 10, the manufacturing method of the adhesive film for a circuit connection is demonstrated.

FIG. 5 is a diagram schematically showing a longitudinal section of a substrate used in a method of manufacturing the adhesive film 10A for circuit connection. FIG. 6 is a view showing a modification of the cross-sectional shape of the recessed portion of the base body of FIG. 5 . FIG. 7 is a cross-sectional view schematically showing a state in which the conductive particles 4 are arranged in the concave portion of the base of FIG. 5 . FIG. 8 is a cross-sectional view schematically showing an example of a preparation step. FIG. 9 is a cross-sectional view schematically showing an example of a transfer step. FIG. 10 is a cross-sectional view schematically showing an example of a light irradiation step.

(preparatory steps) In the preparation step, first, the base body 6 (see FIG. 5 ) having a plurality of recesses 7 on the surface is prepared. The base body 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, the adhesive film 10A for circuit connections in which the conductive particles 4 are regularly arranged in a predetermined pattern (the pattern shown in FIGS. 2 and 3 ) can be obtained.

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

The shape of the recessed portion 7 in the longitudinal section of the base body 6 (the cross-sectional shape of the recessed portion 7 ) may be, for example, the shape shown in FIGS. 6( a ) to ( h ). In any of the cross-sectional shapes shown in FIGS. 6( a ) to ( h ), the width (width b) of the opening of the concave portion 7 is the maximum width in the cross-sectional shape. Thereby, the conductive particles arranged in the concave portion 7 can be easily taken out, and the workability is improved.

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

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

As the material constituting the substrate 6, for example, inorganic materials such as silicon, various ceramics, glass, and metals such as stainless steel, and organic materials 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 base 6 by forming the conductive particles 4 in the recesses 7 of the base 6 . In this case, the base 6 may have The heat resistance of the particles (eg, solder particles) of the conductive particles 4 that do not deteriorate at the melting temperature.

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

The arrangement method of the conductive particles 4 is not particularly limited. The arrangement method can be either dry or wet. For example, by arranging the conductive particles 4 on the surface 6a of the base body 6, and scraping the surface 6a of the base body 6 with a scraper or a micro-bonding roller, the excess conductive particles 4 can be removed, and the conductive particles 4 can be placed in the recesses 7 at the same time. . When the width b of the opening of the concave portion 7 is larger than the depth of the concave portion 7 , the conductive particles may fly out from the opening of the concave portion 7 . When a squeegee is used, the conductive particles flying out from the opening of the recessed portion 7 are removed. As a method of removing excess conductive particles, a method of blowing compressed air and scraping the surface 6a of the base 6 with a nonwoven cloth or a fiber bundle can also be mentioned. These methods have weaker physical force than squeegees, and are therefore preferable in handling easily deformable particles (eg, solder particles) as conductive particles.

When using solder particles as the conductive particles 4 , the conductive particles 4 can be arranged in the recesses 7 by forming the conductive particles 4 (solder particles) in the recesses 7 of the base 6 . Specifically, for example, as shown in FIGS. 8( a ) to ( b ), after the particles 8 (solder particles) for forming the conductive particles 4 are accommodated in the concave portion 7 , the particles 8 accommodated in the concave portion 7 are melted, Thereby, the conductive particles 4 can be formed in the recesses 7 . The microparticles 8 accommodated in the concave portion 7 are united by fusion and spheroidized by surface tension. At this time, in the contact portion with the bottom portion 7a of the recessed portion 7, the molten metal has a shape that follows the bottom portion 7a. Therefore, for example, when the bottom portion 7a of the recessed portion 7 is a flat shape as shown in FIG. 8( a ), the conductive particle 4 has a flat portion 4 a in a part of the surface shown in FIG. 8( b ).

The fine particles 8 only need to be able to be accommodated in the concave portion 7, the particle size distribution may have a large variation, and the shape may be deformed.

As a method of melting the microparticles 8 accommodated in the concave portion 7, a method of heating the microparticles 8 to the melting point or higher of the material forming the microparticles can be mentioned. The fine particles 8 may not be melted, not spread by wetting, or may not coalesce even if they are heated at a temperature 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 oxide film on the surfaces of the fine particles 8 , and then heated to a temperature equal to or higher than the melting point of the fine particles 8 . Thereby, the fine particles 8 are easily melted, wetted and spread, and integrated into one. From the same viewpoint, the melting of the fine particles 8 may be performed in a reducing atmosphere.

The method of setting it as a reducing atmosphere is not particularly limited as long as the above-mentioned effects can be obtained, and for example, there are methods using hydrogen gas, hydrogen radicals, 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 these conveyance furnaces or continuous furnaces, the fine particles 8 can be melted under a reducing atmosphere. These apparatuses can be equipped with heating means in the furnace, a chamber filled with inert gas (nitrogen, argon, etc.), a mechanism for setting a vacuum in the chamber, etc., thereby making it easier to control the reducing gas. In addition, 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 integrated into one, and the conductive particles 4 with further excellent connection stability can be obtained.

Profiles such as reduction, dissolution conditions, temperature, and furnace atmosphere adjustment of the microparticles 8 can be appropriately set in consideration of the melting point, particle size, size of the concave portion, and material of the substrate 6 of the microparticles 8 .

According to the above method, the conductive particles 4 of substantially uniform size can be formed regardless of the material and shape of the fine particles 8 . In addition, the size and shape of the conductive particles 4 depend on the amount of the particles 8 accommodated in the concave portion 7 , the shape of the concave portion 7 , and the like. Therefore, the conductive particle can be freely designed by the design of the concave portion 7 (adjustment of the size, shape, etc. of the concave portion). The size and shape of 4 can easily prepare conductive particles with a target particle size distribution (for example, conductive particles with an average particle size of 1 to 30 μm and a C.V. value of particle size of 20% or less).

The above method is especially suitable for the case where the conductive particles 4 are indium-based solder particles. Indium-based solder can be precipitated by plating, but is difficult to precipitate in the form of particles, and is a material that is soft and difficult to handle. However, in the above-described method, by using the indium-based solder fine particles as a raw material, indium-based solder particles having a substantially uniform particle diameter can be easily produced.

After the conductive particles 4 are arranged in the recesses 7 , the substrate 6 can be handled in a state where the conductive particles 4 are arranged (stored) in the recesses 7 . For example, when the substrate 6 is transported/stored in a state where the conductive particles 4 are arranged (stored) in the recesses 7 , deformation of the conductive particles 4 (especially soft conductive particles such as solder particles) can be prevented. In addition, since the conductive particles 4 are easily taken out in the state where the conductive particles 4 are arranged (stored) in the recesses 7 , it is also easy to prevent the conductive particles 4 from being deformed during collection, surface treatment, or the like.

(transfer step) In the transfer step, by providing a photocurable component (the above-mentioned (B) component) and the first thermosetting component (the above-mentioned (C) component) on the surface of the base 6 (the surface on which the concave portion 7 is formed) The composition layer 9 transfers the conductive particles 4 to the composition layer 9 (see FIG. 9 ).

Specifically, first, the composition layer 9 containing the components (B) and (C) is formed on the support body 11 to obtain the laminated film 12 , and then the surface of the base body 6 on which the recesses 7 are formed (the surface of the base body 6 ) 6a is opposed to the surface of the laminate film 12 on the side of the composition layer 9 (the surface 9a of the composition layer 9 on the opposite side of the support body 11 ), and the base 6 and the composition layer 9 are brought close to each other (see FIG. 9( a ) ). Next, the conductive particles 4 are transferred to the composition layer 9 by bonding the laminate film 12 to the base 6 so that the composition layer 9 is brought into contact with the surface (surface on which the recesses 7 are formed) 6 a of the base 6 . Thereby, the particle transfer layer 13 including the composition layer 9 and the conductive particles 4 at least partially embedded in the composition layer 9 can be obtained (see FIG. 9( b )). At this time, when the bottom of the concave portion 7 is flat, the conductive particles 4 have a flat portion 4 a corresponding to the shape of the bottom of the concave portion 7 , and the flat portion 4 a is disposed in a state where the flat portion 4 a faces the opposite side to the support body 11 . in the composition layer 9 .

The composition layer 9 can be formed using a varnish composition (a varnish-like first adhesive composition), which is formed by adding the components (B) and (C), and other components added as needed in an organic medium. It is prepared by stirring, mixing, kneading, etc. to dissolve or disperse it. Specifically, for example, using an air knife coater, a roll coater, an applicator, a cut-out wheel coater, a die coater, or the like, on the support 11 (eg, a substrate subjected to mold release treatment) After the varnish composition is applied, the composition layer 9 can be formed by volatilizing the organic medium by heating. At this time, by adjusting the coating amount of the varnish composition, the thickness of the finally obtained first adhesive layer (first adhesive film) can be adjusted.

The organic medium used for the preparation of the varnish composition is not particularly limited as long as it has the properties of being able to dissolve or disperse each component substantially uniformly. As such an organic medium, toluene, acetone, methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate, propyl acetate, butyl acetate, etc. are mentioned, for example. These organic media can be used individually or in combination of 2 or more types. Stirring mixing or kneading at the time of preparing the varnish composition can be performed using, for example, a stirrer, a mill, three rolls, a ball mill, a bead mill, a homodispersor, or the like.

The support 11 is not particularly limited as long as it has heat resistance capable of withstanding the heating conditions at the time of volatilizing the organic medium. The support body 11 can be a plastic film or a metal foil. As the support 11 , for example, oriented polypropylene (OPP), polyethylene terephthalate (PET), polyethylene naphthalate, polyethylene isophthalate, polyethylene terephthalate, and polyethylene terephthalate can be used. Butylene Diformate, Polyolefin, Polyacetate, Polycarbonate, Polyphenylene Sulfide, Polyamide, Polyimide, Cellulose, Ethylene Vinyl Acetate Copolymer, Polyvinyl Chloride, Polyvinylidene Vinyl chloride, synthetic rubber, liquid crystal polymer, etc. are used as the base material (for example, film) of the constituent material, etc.

The heating conditions at the time of volatilizing the organic medium from the varnish composition applied on the substrate 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.

As a method of bonding the laminated film 12 and the base body 6, methods, such as hot pressing, roll lamination, and vacuum lamination, are mentioned, for example. The lamination can be performed, for example, under a temperature condition of 0 to 80°C.

In the transfer step, the composition layer 9 can be formed by directly applying the varnish composition to the base 6, but the support 11, the composition layer 9 and the conductive layer 9 can be easily obtained by using the laminated film 12 as described above. The particle transfer layer 13 in which the particles 4 are formed as a single body tends to be able to easily perform the light irradiation step described later.

(light irradiation step) In the light irradiation step, component (B) in the composition layer 9 is cured by irradiating the composition layer 9 (particle transfer layer 13 ) with light (active ray) to form the first adhesive layer 1 (see FIG. 10).

Regarding the irradiation of light, irradiation light (eg, ultraviolet light) having a wavelength in the range of 150 to 750 nm can be used. The irradiation of light can be performed using, for example, a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, an extra high pressure mercury lamp, a xenon lamp, a metal halide lamp, an LED light source, or the like. The accumulated light amount of the irradiated light can be appropriately set, but may be, for example, 500 to 3000 mJ/cm ² .

As indicated by the arrows in FIG. 10( a ), in FIG. 10( a ), light is irradiated from the side opposite to the support 11 (the side of the conductive particles 4 to be transferred in the composition layer 9 ), but the When the support body 11 transmits light, the light may be irradiated from the support body 11 side. In addition, in FIG. 10( a ), light is irradiated after the substrate 6 is separated from the particle transfer layer 13 , but light may be irradiated before the substrate 6 is separated. At this time, light may be irradiated after peeling off the support body 11 .

(layering step) In the lamination step, the second adhesive layer 2 is provided on the surface of the first adhesive layer 1 opposite to the support 11 (the side of the composition layer 9 on which the conductive particles 4 are to be transferred). Thereby, the adhesive film 10A for circuit connection shown in FIG. 1 can be obtained.

The second adhesive layer 2 uses a varnish prepared by dissolving or dispersing the second thermosetting component (the above-mentioned (C) component) and other components added as necessary in an organic medium by stirring, mixing, kneading, etc. The composition (varnish-like second adhesive composition) can be provided on the substrate 6 in the same manner as the method for providing the composition layer 9 on the substrate 6, except that the varnish-like first adhesive composition is replaced. on the first adhesive layer 1 . That is, it is possible to provide the second adhesive layer 2 on the first adhesive layer 1 by laminating the laminated film obtained by forming the second adhesive layer 2 on the support with the first adhesive layer 1, and also The second adhesive layer 2 can be provided on the first adhesive layer 1 by directly applying the varnish-like second adhesive composition to the first adhesive layer 1 .

In the lamination step, by providing the second adhesive layer 2 on the surface opposite to the support 11 as described above, it is expected to improve the adhesion of the adhesive film for circuit connection to the circuit member and suppress the connection peeling. In the lamination step, the second adhesive layer 2 may be provided on the surface on the side where the support 11 is provided after peeling off the support 11 . In this case, the lamination step may be performed before the light irradiation step, or may be performed before the transfer step.

As mentioned above, although the manufacturing method of the adhesive film 10A for circuit connections was exemplified, and the manufacturing method of the adhesive film for circuit connections of one Embodiment was demonstrated, this invention is not limited to the said embodiment.

For example, the manufacturing method of the adhesive film for circuit connection may further include the process of providing a 3rd adhesive layer on the surface of the opposite side to the 2nd adhesive layer of a 1st adhesive layer (2nd lamination|stacking process). In this method, the adhesive film for circuit connection (for example, the adhesive film 10B for circuit connection shown in FIG. 4) which further has a 3rd adhesive layer can be obtained.

In the second lamination step, a composition (third adhesive composition) containing the third thermosetting component (the above-mentioned (C) component) and other components added as necessary is provided instead of the second adhesive composition, Otherwise, the third adhesive layer can be provided on the first adhesive layer in the same manner as in the above-described lamination step (first lamination step) for providing the second adhesive layer. The second lamination step can be performed before the first lamination step.

<Connected structure and its manufacturing method> Hereinafter, the connection structure (circuit connection structure) and its manufacturing method are demonstrated using the aspect which uses the said adhesive film 10A for circuit connections as a 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 circuit board 21 and a first electrode 22 formed on a main surface 21 a of the first circuit board 21 , and a second circuit member 26 having The second circuit board 24, the second electrode 25 formed on the main surface 24a of the second circuit board 24, and the connection portion 27, including the cured body of the adhesive film 10A for circuit connection, 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 are bonded together.

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 may be glass substrates or plastic substrates on which circuit electrodes are formed; printed wiring boards; ceramic wiring boards; flexible wiring boards; IC chips such as driving ICs. The first circuit board 21 and the second circuit board 24 may be formed of inorganic substances such as semiconductors, glass, and ceramics, organic substances such as polyimide and polycarbonate, and composites such as glass/epoxy. The first circuit substrate 21 may be a plastic substrate. The first circuit member 23 can be, for example, a plastic substrate on which circuit electrodes are formed (a plastic substrate using organic substances such as polyimide, polycarbonate, polyethylene terephthalate, and cycloolefin polymers as constituent materials), The circuit member 26 may be, for example, an IC chip such as a driver IC. The plastic substrate on which the electrodes are formed can be formed by regularly arranging pixel driving circuits such as organic TFTs or a plurality of organic EL elements R, G, and B on the plastic substrate to form a display area.

The first electrode 22 and the second electrode 25 may be made of metals including gold, silver, tin, ruthenium, rhodium, palladium, osmium, iridium, platinum, copper, aluminum, molybdenum, titanium, etc., indium tin oxide (ITO), indium zinc Electrodes of oxides such as oxide (IZO), indium gallium zinc oxide (IGZO), etc. 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 laminating two or more types may be two or more layers or three or more layers. The first electrodes 22 and the second electrodes 25 may be circuit electrodes or bump electrodes. In FIG. 11 , the first electrodes 22 are circuit electrodes, and the second electrodes 25 are bump electrodes.

The connection portion 27 has, for example, a first region 28 located on the side of the first circuit member 23 in a direction in which the first circuit member 23 and the second circuit member 26 face each other (hereinafter referred to as "opposing direction"), and includes the above-mentioned first circuit member 23 . 1. 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; the second region 29 is located on the side of the second circuit member 26 in the opposing direction, and includes the above-mentioned The cured product of the component (C) and the like in the second adhesive layer; and the conductive particles 4 (or the molten solidified product of the conductive particles 4 ) are interposed at least between the first electrode 22 and the second electrode 25 to connect the first electrode 22 and the second electrode 25 are electrically connected to each other. The connecting portion 27 does not have to have two distinct regions between the first region 28 and the second region 29, and one can be formed by mixing the cured product derived from the first adhesive layer and the cured product derived from the second adhesive layer. area.

Examples of the connecting structure include a flexible organic electroluminescence color display (organic EL display) in which a plastic substrate on which organic EL elements are regularly arranged and a drive circuit element serving as a driver for image display are connected, and a regular A touch panel or the like is formed by connecting a plastic substrate with organic EL elements and a position input element such as a touch panel. The connection structure can be applied to various monitors such as smartphones, tablet computers, televisions, navigation systems of vehicles, wearable terminals, etc.; furniture; home appliances; daily necessities, etc.

FIG. 12 is a schematic cross-sectional view showing an embodiment of a method of manufacturing the connection structure 100 . 12(a) and 12(b) are schematic cross-sectional views showing each step. As shown in FIG. 12 , the method of manufacturing the connection structure 100 includes the steps of arranging between the surface of the first circuit member 23 on which the first electrodes 22 are provided and the surface of the second circuit member 26 on which the second electrodes 25 are provided. The above-mentioned adhesive film 10A for circuit connection; and the laminate including the first circuit member 23, the adhesive film 10A for circuit connection, and the second circuit member 26 are heated in a state of being pressed in the thickness direction of the laminate. This electrically connects the first electrode 22 and the second electrode 25 to each other via the conductive particles 4 (or a molten solidified product of the conductive particles 4 ), and connects the first circuit member 23 and the second circuit member 26 to each other.

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

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 are opposed to each other, and an adhesive for circuit connection is arranged between the first circuit member 23 and the second circuit member 26 Film 10A. For example, as shown in FIG. 12( a ), the adhesive film 10A for circuit connection is laminated on the first circuit member 23 with the first adhesive layer 1 side facing the main surface 21 a of the first circuit board 21 . Next, on the first circuit member 23 on which the adhesive film 10A for circuit connection is 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.

Then, as shown in FIG. 12( b ), a laminate in which the first circuit member 23 , the adhesive film 10A for circuit connection, and the second circuit member 26 are laminated in this order is pressed in the thickness direction of the laminate. Heating is performed in the state, and the first circuit member 23 and the second circuit member 26 are thermocompression-bonded to each other. At this time, as indicated by the arrows in FIG. 12( b ), the flowable uncured thermosetting components contained in the first adhesive layer 1 and the second adhesive layer 2 flow so as to fill the adjacent areas. The gaps between the electrodes (the gap between the first electrodes 22 and the gap between the second electrodes 25 ) are cured by the above heating. Thereby, 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 bonded to each other, so that the connection structure 100 shown in FIG. 11 can be obtained.

In the above-described method of manufacturing the bonded structure 100, since a part of the first adhesive layer 1 is cured by light irradiation, the flow of the conductive particles in the first adhesive layer 1 is suppressed, and therefore, the conductive particles can be placed between the opposing electrodes. The conductive particles are efficiently and efficiently trapped. In addition, since the thermosetting components contained in the first adhesive layer 1 and the second adhesive layer 2 flow during thermocompression bonding, it is difficult for the resin to intervene between the conductive particles 4 and the electrodes (the first electrode and the second electrode) after the connection. ), the connection resistance between the opposing first electrodes 22 and the second electrodes 25 can be reduced.

When solder particles are used as conductive particles, the solder particles are melted and aggregated between the first electrode 22 and the second electrode 25 to form a solder layer, and then the solder layer is fixed to the first electrode 22 by cooling. Between the second electrode 25 , 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 solder particles are used as conductive particles, the temperature may be at which the solder particles can be melted (for example, a temperature higher than the melting point of the solder particles), for example, 130 to 260°C. The pressure is not particularly limited as long as it does not damage the adherend, but in the case of COP mounting, for example, the area-converted pressure on the bump electrode can be 0.1 to 50 MPa, or 40 MPa or less. It may also be 0.1 to 40 MPa. In addition, in the case of COG mounting, for example, the area conversion pressure on the bump electrode may be 10 to 100 MPa. These heating and pressing times may be in the range of 0.5 to 120 seconds. [Example]

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

In Examples and Comparative Examples, the following materials were used as (B1) component, (B2) component, (C1) component, (C2) component, (C3) component, (C4) component, and (D) component , (E) components and (F) components. (B1) component: radically polymerizable compound • NK Ester A-BPEF (9,9-bis[4-(2-propenyloxyethoxy)phenyl]pyridine, manufactured by SHIN-NAKAMURA CHEMICAL CO, LTD.) • RIPOXY VR-90 (Bisphenol A type epoxy methacrylate, manufactured by SHOWA DENKO K.K.) •CYCLOMER M100 (3,4-epoxycyclohexyl methyl methacrylate, manufactured by Daicel Corporation) •A-1000 (Polyethylene glycol diacrylate, manufactured by SHIN-NAKAMURA CHEMICAL CO, LTD.) •A9300-1CL (caprolactone-modified tris-(2-propenyloxyethyl) isocyanate, manufactured by SHIN-NAKAMURA CHEMICAL CO, LTD.) (B2) Component: photo-radical polymerization initiator • Irgacure OXE-02 (1-[9-ethyl-6-(2-methylbenzyl)-9H-carbazol-3-yl]-ethanone 1-(o-acetoxime), BASF Japan Ltd. manufactures) • Omnirad907 (2-methyl-1-[4-(methylthio)phenyl]-2-merolinopropan-1-one, manufactured by IGM RESINS B.V.) (C1) component: cationic polymerizable compound •ETERNACOLL OXBP (4,4'-bis[(3-ethyl-3-oxetanyl)methoxymethyl]biphenyl, manufactured by UBE INDUSTRIES, LTD.) • CELLOXIDE8010 (bis-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 cationic polymerization initiator (thermal latent cation generator) • CXC-1821 (quaternary ammonium salt type thermal acid generator, manufactured by King Industries), •SI-60L (aromatic sulfonium salt type thermal acid generator, manufactured by SANSHIN CHEMICAL INDUSTRY CO.,LTD.) (C3) component: anionic polymerizable compound • HP-4032D (1,6-bis(oxiranylmethoxy)naphthalene, manufactured by DIC CORPORATION) (C4) Component: thermal anionic polymerization initiator (thermal latent anion generator) •HX-3941HP (Microcapsule-type imidazole-based curing accelerator, manufactured by Asahi Kasei Corporation) (D) Component: Thermoplastic resin •P-1: Phenoxy phenoxy resin synthesized by the method described later •YP-70 (Bisphenol A/Bisphenol F copolymerized phenoxy resin, manufactured by NIPPON STEEL Chemical & Material Co., Ltd.) (E) Component: Coupling agent •KBM-403 (γ-glycidoxypropyltrimethoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd.) (F) Ingredient: Filler •AEROSIL R805 (hydrolyzate of trimethoxyoctylsilane and silica (fine silica), manufactured by Evonik Industries AG, diluted with an organic solvent to a non-volatile content of 10% by mass)

(Synthesis of P-1) 45 g of 4,4'-(9-perylene)-diphenol (manufactured by Sigma-Aldrich Japan K.K.) and 50 g of 3,3',5,5'-tetramethylbisphenol diglycidyl ether (YX- 4000H, manufactured by Mitsubishi Chemical Corporation) was dissolved in N-methylpyrrolidine in a 3000 mL three-necked flask equipped with a Days cooling tube, a calcium chloride tube, and a Teflon stirring bar ("Teflon" is a registered trademark) connected to a stirring motor. 1000 mL of ketone was used as a reaction solution. 21 g of potassium carbonate was added to this, and it stirred, heating to 110 degreeC using a heating mantle. After stirring for 3 hours, the reaction was added dropwise to a beaker containing 1000 mL of methanol, and the resultant precipitate was subjected to suction filtration to collect by filtration. Furthermore, the precipitate collected by filtration was washed three times with 300 mL of methanol, and 75 g of phenoxy resin P-1 was obtained.

Then, the molecular weight of the phenoxy resin P-1 was measured using a high performance liquid chromatograph GP8020 manufactured by TOSOH CORPORATION (column: Gelpak GL-A150S and GLA160S manufactured by Hitachi Chemical Company, Ltd., eluent: tetrahydrofuran , flow rate: 1.0ml/min). As a result, 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 base (PET film, thickness: 55 μm) having a plurality of recesses on the surface was prepared. The concave portion is a conical trapezoid whose opening area expands toward the surface side of the base (the center of the bottom is the same as the center of the opening when viewed from the top of the opening), the diameter of the opening is 4.3 μmφ, the diameter of the bottom is 4.0 μmφ, and the depth is set to 4.3 μmφ. is 4.0 μm. In addition, a plurality of recesses were regularly formed in a three-way array at intervals of 6.2 μm (distance between the centers of the bottoms) so that there were 29,000 recesses per 1 mm square.

[Step (a2): Configuration of Conductive Particles] As component (A), conductive particles (average particle size: 3.3 μm, C.V. particle size of C.V. value: 2.8%, specific gravity: 2.9), which was arranged on the surface of the base body on which the concave portion was formed. Next, excess conductive particles were removed by scraping the surface of the substrate in which the recesses were formed with a micro-bonding roller, and the conductive particles were arranged only in the recesses. In addition, the average particle diameter of the conductive particles and the C.V. value of the particle diameter are the following values. That is, the first adhesive layer produced through the steps (b) and (c) described later is cut into 10 cm×10 cm, and the conductive particles are arranged After the surface of the particles was subjected to Pt sputtering, 300 conductive particles were observed and measured by SEM.

(Step (b): Transfer Step) [Step (b1): Preparation of Composition Layer] (B1) component, (B2) component, (C1) component, (C2) component, (D) component, (E) component and (F) component shown in Table 1 were blended as shown in Table 1 The amount (unit: part by mass, solid content) was mixed with an organic solvent (2-butanone) to obtain a resin solution. Next, the resin solution was coated on a PET film with a thickness of 38 μm that had undergone a silicone release treatment, and was dried with hot air at 60° C. for 3 minutes, thereby forming a composition layer with a thickness of 1.5 μm on the PET film. .

【Table 1】 type Blending amount (parts by mass) (B1) Ingredients A-BPEF 10 VR-90 10 (B2) Ingredients OXE-02 0.5 (C1) Ingredients OXBP 20 CEL8010 20 (C2) Ingredients CXC-1821 7 (D) Ingredients P-1 20 YP-70 20 (E) Ingredients KBM-403 5 (F) Ingredients R805 10

[Step (b2): Transfer of Conductive Particles] The above-mentioned composition layer formed on the PET film produced in step (b1) and the substrate formed in step (a) with the conductive particles arranged in the concave portions are disposed opposite to each other, and the conductive particles are transferred to the composition layer.

(Step (c): Light Irradiation Step) For the composition layer of the conductive particles to be transferred, a UV curing oven (manufactured by Ushio Inc., UVC-2534/1MNLC3- XJ01) Irradiated ultraviolet rays with a cumulative light intensity of 1700 mJ/cm ² (wavelength: 365 nm) to activate the component (B2) and polymerize the component (B1). Thereby, the photocurable components (component (B1) and component (B2)) in the composition layer are cured, and the first adhesive layer is formed.

(Step (d): Layering step) [Step (d1): Preparation of Second Adhesive Layer] (C1) Component, (C2) Component, (D) Component, (E) Component and (F) Component shown in Table 2 are blended in the amounts shown in Table 2 (unit: mass part, solid content amount ) was mixed with an organic solvent (2-butanone) to obtain a resin solution. Next, the resin solution was coated on a PET film with a thickness of 50 μm that had undergone a silicone release treatment, and was dried with hot air at 60° C. for 3 minutes, thereby producing a second adhesive film with a thickness of 12.5 μm on the PET film. agent layer.

【Table 2】 type Blending amount (parts by mass) (C1) Ingredients OXBP 25 CEL8010 25 jER1010 40 (C2) Ingredients CXC-1821 7 (D) Ingredients P-1 10 (E) Ingredients KBM-403 5 (F) Ingredients R805 10

[Step (d2): Lamination of the second adhesive layer] The first adhesive layer produced in the step (c) and the second adhesive layer produced in the step (d1) were bonded together while applying a temperature of 50°C. Thereby, an anisotropic conductive adhesive film (thickness: 14 μm) having a double-layer structure was obtained.

<Example 2> In addition to the steps (a) to (d), the following step (e) was performed, and an anisotropic conductive adhesive film was produced in the same manner as in Example 1.

(Step (e): 2nd layer-up step) [Step (e1): Preparation of the third adhesive layer] The (C1) component, (C2) component, (D) component, (E) component and (F) component shown in Table 3 were blended in the amount shown in Table 3 (unit: mass part, solid content amount ) was mixed with an organic solvent (2-butanone) to obtain a resin solution. Next, the resin solution was coated on a PET film with a thickness of 50 μm that had undergone a silicone mold release treatment, and was dried with hot air at 60° C. for 3 minutes, thereby producing a third adhesive film with a thickness of 2.0 μm on the PET film. agent layer.

【table 3】 type Blending amount (parts by mass) (C1) Ingredients OXBP 25 CEL8010 25 (C2) Ingredients CXC-1821 7 (D) Ingredients P-1 20 (E) Ingredients KBM-403 5 (F) Ingredients R805 10

[Step (e2): Lamination of the 3rd Adhesive Layer] While applying a temperature of 50°C, 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 step (d2) and the first adhesive layer exposed in step (e1) ) The third adhesive layer produced in ) was bonded. Thereby, an anisotropic conductive adhesive film (thickness: 16 μm) having a three-layer structure was obtained.

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

【Table 4】 type Blending amount (parts by mass) Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Example 9 Example 10 Comparative Example 1 (B1) Ingredients A-BPEF 10 7 5 2.5 7 7 7 10 - VR-90 10 7 5 2.5 7 7 7 10 - CYM M100 - - - - 6 - - - - A-1000 - - - - - 6 - - - A9300-1CL - - - - - - 6 -- - (B2) Ingredients OXE-02 0.5 0.5 0.2 0.2 0.5 0.5 0.5 0.2 - (C1) Ingredients OXBP 25 20 25 25 20 25 25 25 25 CEL8010 25 20 25 25 20 25 25 25 25 (C2) Ingredients CXC-1821 7 7 7 7 7 7 7 7 7 (D) Ingredients P-1 20 20 20 20 20 20 20 20 25 YP-70 20 20 20 20 20 20 20 20 25 (E) Ingredients KBM-403 5 5 5 5 5 5 5 5 5 (F) Ingredients R805 10 10 10 10 10 10 10 10 10

<Example 11> The anisotropic conductivity of the three-layer structure was produced in the same manner as in Example 10, except that the cumulative light intensity of the irradiated light was changed to 2000 mJ/cm ² in step (c). Adhesive film.

<Example 12> In the same manner as in Example 10, except that the cumulative light intensity of the irradiated light was changed to 2300 mJ/cm ² in the step (c), anisotropic conductivity of a three-layer structure was produced in the same manner as in Example 10. Adhesive film.

<Example 13> In step (b1), as the component (B2), 1.0 parts by mass of Omnirad907 was used instead of Irgacure OXE-02, and the cumulative light amount of light was changed to 2000 mJ/cm ² , except that In the same manner as in Example 2, an anisotropic conductive adhesive film having a three-layer structure was produced.

<Example 14> In step (b1) and step (d1), as the component (C1), 40 parts by mass of YL983U was used instead of ETERNACOLL OXBP and CELLOXIDE8010; and as the component (C2), 7 parts by mass of SI-60L was used instead of Except for CXC-1821, in the same manner as in Example 1, an anisotropic conductive adhesive film having a double-layer structure was produced.

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

<Example 16> The following step (a2') was performed in place of the step (a2), and the substrate obtained in the following step (a2') was used as the substrate in which the conductive particles were arranged in the concave portion used in the step (b2), and In the same manner as in Example 1, an anisotropic conductive adhesive film of a double-layer structure was produced.

[Step (a2'): Preparation and Arrangement of Solder Particles] 100 g of Sn-Bi solder particles (manufactured by 5N Plus Inc., melting point 138°C, type 8) were immersed in distilled water, ultrasonically dispersed, and then flattened, thereby recovering the solder particles floating in the supernatant. This operation was repeated, and 10 g of solder particles were recovered. The average particle diameter of the obtained solder fine particles was 1.0 μm, and the C.V. value of the particle diameter was 42%. Next, the obtained solder fine particles (average particle diameter: 1.0 μm, C.V. value of particle diameter: 42%) were placed on the surface of the base body prepared in the step (a1) on which the recesses were formed. Next, the excess solder particles were removed by scraping the surface of the substrate in which the recesses were formed with a micro-bonding roller, and the solder particles were arranged only in the recesses. Next, the substrate with the solder particles arranged in the concave portion was put into a hydrogen radical reduction furnace (manufactured by SHINKO SEIKI CO., LTD., hydrogen plasma reflow apparatus), and after vacuuming, hydrogen gas was introduced into the furnace, and the furnace was Filled with hydrogen. Then, the inside of the furnace was adjusted to 120° C., and hydrogen radicals were irradiated for 5 minutes. Then, the hydrogen in the furnace was removed by vacuuming, and after heating to 145° C., nitrogen gas was introduced into the furnace to return to atmospheric pressure, and then the temperature in the furnace was lowered to room temperature, thereby forming solder particles. Thereby, the base|substrate which arrange|positioned the electroconductive particle (solder particle) in the recessed part used in step (b2) is prepared.

In addition, solder particles were produced by the same operation, and the obtained solder particles were recovered from the concave portion by hitting the back side of the concave portion of the base. It was confirmed that a part of the surface of the solder particle had a flat portion, and the ratio (B/A) of the diameter B of the flat portion to the diameter A of the solder particle was 0.15. In addition, it was confirmed that when a quadrilateral circumscribing the projected image of the solder particle is formed from two pairs of parallel lines, and the distance between the opposing sides is taken as X and Y (wherein, Y<X), Y/X is 0.93. . In addition, when the average particle diameter and the C.V. value of the particle diameter of the solder particles were measured, the average particle diameter was 3.8 μm, and the C.V. value of the particle diameter was 7.9%. In addition, the average particle size, B/A, and Y/X of the solder particles are values such that the first adhesive layer produced in the steps (b) and (c) is cut into 10 cm×10 cm, and the After the surface of the particles was subjected to Pt sputtering, 300 solder particles were observed and measured by SEM.

<Example 17> In the same manner as in Example 2, except that the above-mentioned step (a2') was carried out in place of the step (a2), an anisotropic conductive adhesive film having a three-layer structure was produced.

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

<Evaluation> (Evaluation of Transfer Rate of Conductive Particles) About the anisotropic conductive adhesive films of Examples 1 to 17 and Comparative Examples 1 to 2, a microscope and an image analysis software (ImagePro, Hakuto) were used. Co., Ltd.), measure the number of conductive particles per 25,000 μm ² at 20 locations, convert the average value to the number of conductive particles per 1 mm ² , divide this number by the number of recesses formed on the substrate, and measure The transfer rate of conductive particles (see the following formula). The case where the transfer rate of conductive particles was 95% or more was evaluated as "S" judgment, and the case where the transfer rate of conductive particles was 90% or more and less than 95% was evaluated as "A" judgment, and the transfer rate of conductive particles was evaluated as "A" judgment. The case where the ratio was 80% or more and less than 90% was evaluated as "B" judgment, and the case where the transfer rate of conductive particles was less than 80% was evaluated as "C" judgment. 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 the recesses formed on the substrate) × 100

(Evaluation of Capture Rate of Conductive Particles and Evaluation of Connection Resistance) [Preparation of circuit components] As the first circuit member (a), AlNd (100 nm) was prepared on the surface of an alkali-free glass substrate (OA-11, manufactured by Nippon Electric Glass Co., Ltd., external shape: 38 mm×28 mm, thickness: 0.3 mm). /Mo (50 nm)/ITO (100 nm) wiring pattern (pattern width: 19 μm, space between electrodes: 5 μm). As the first circuit member (b), an alkali-free glass substrate (OA-11, manufactured by Nippon Electric Glass Co., Ltd., outer shape: 38 mm×28 mm, thickness: 0.3 mm) was prepared in which Cr (20 nm) was formed on the surface /Au (200 nm) wiring pattern (pattern width: 19 μm, space between electrodes: 5 μm). As the second circuit member, an IC chip in which bump electrodes were arranged in two rows in a staggered pattern was prepared (outline: 0.9 mm × 20.3 mm, thickness: 0.3 mm, size of bump electrodes: 70 μm × 12 μm, between bump electrodes space: 12 μm, bump electrode thickness: 8 μm).

[Preparation of Connected Structure (a)] Using the anisotropic conductive adhesive films of Examples 1 to 13 and Comparative Examples 1 to 2, respectively, a connected structure (a) was prepared. An anisotropic conductive adhesive film is arrange|positioned on the 1st circuit member (a) so that a 1st adhesive layer or a 3rd adhesive layer may contact a 1st circuit member (a). Using a thermocompression bonding apparatus (BS-17U, manufactured by OHASHI ENGINEERING Co., Ltd.) consisting of a stage including a ceramic heater and a tool (8mm x 50mm), at 70°C, 0.98MPa (10kgf/cm ² ) The anisotropic conductive adhesive film was adhered to the first circuit member (a) by heating and pressurizing under the conditions for 2 seconds, and the anisotropic conductive adhesive film was peeled off the opposite to the first circuit member (a). release film on one side. Next, after aligning the bump electrodes of the first circuit member (a) and the circuit electrodes of the second circuit member, heating/pressurizing at 130° C. at 40 MPa for 5 seconds was performed to bond the anisotropic conductivity. The second adhesive layer of the agent film was bonded to the second circuit member to produce a connected structure (a). In addition, the temperature represents the actual measured maximum temperature of the anisotropic conductive adhesive thin film, and the pressure represents the value calculated for the total area of the surfaces of the second circuit member facing the bump electrodes and the first circuit member (a).

[Preparation of Linked Structure (b)] As the anisotropic conductive adhesive film, the anisotropic conductive adhesive film of Example 14 was used; and the bonding structure ( In the same manner as the production of a), the connecting structure (b) was produced.

[Preparation of Linked Structure (c)] As the anisotropic conductive adhesive film, the anisotropic conductive adhesive film of Example 15 was used; and the bonding structure ( In the same manner as the production of a), the connecting structure (c) was produced.

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

[Evaluation of Capture Rate of Conductive Particles] In the production of the above-mentioned connected structures (connected structures (a) to (d)) using the anisotropic conductive adhesive films of Examples 1 to 17 and Comparative Examples 1 to 2, the convex The capture rate of conductive particles between the bulk electrode and the circuit electrode was evaluated. Here, the capture rate of conductive particles refers to the ratio of the density of conductive particles on the bump electrode to the density of conductive particles in the anisotropic conductive adhesive film, and was calculated according to the following formula. In addition, the average of the number of conductive particles on the bump electrodes was obtained by observing the mounted circuit member from the glass substrate side using a differential interference microscope, and measuring the number of trapped conductive particles per bump. The case where the capture rate of conductive particles was 90% or more was evaluated as "S" judgment, the case where the capture rate of conductive particles was 80% or more and less than 90% was evaluated as "A" judgment, and the capture rate of conductive particles was 70%. % or more and less than 80% were evaluated as "B" judgment, and the case where the capture rate of conductive particles was less than 70% was evaluated as "C" judgment. The results are shown in Tables 5 to 7. Capture rate of conductive particles (%) = (average of the number of conductive particles on the bump electrode / (bump electrode area × conductive particle density in the anisotropic conductive adhesive film)) × 100

[Evaluation of connection resistance] Immediately after the connection structure was fabricated 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 value was used. - The connection resistance of the comparative example 2 was evaluated. The high-temperature and high-humidity test was performed by treating the connected structure in a high-temperature and high-humidity tank with a temperature of 85°C and a humidity of 85% RH for 500 hours. In addition, a digital multimeter (MLR21, manufactured by Kusumoto Chemicals, Ltd.) was used for the measurement of the connection resistance. The case where the connection resistance value was less than 1.0Ω was evaluated as "S" judgment, the case where the connection resistance value was 1.0Ω or more and less than 2.5Ω was evaluated as "A" judgment, and the connection resistance value was 2.5Ω or more and less than 5.0Ω. The case was evaluated as "B" judgment, the case where the connection resistance value was 5.0Ω or more and less than 10.0Ω was evaluated as "C" judgment, and the case where the connection resistance value was 10.0Ω or more was evaluated as "D" judgment. The results are shown in Tables 5 to 7.

【table 5】 Example 1 2 3 4 5 6 7 8 9 transferability A A A A B B S S S Capture rate S A A A B B B B B Connect the resistor (just after installation) Measured value (Ω) 1.9 2.1 2.1 2.2 3.2 2.3 2.1 2.6 2.6 determination A A A A B A A B B Connection resistance (after high temperature and high humidity test) Measured value (Ω) 5.0 5.5 5.5 5.9 6.6 5.6 5.9 8.0 6.6 determination C C C C C C C C C

【Table 6】 Example 10 11 12 13 14 15 16 17 transferability A A A A A S A A Capture rate A S S B A B S A Connect the resistor (just after installation) Measured value (Ω) 2.0 3.0 3.5 2.3 2.0 2.3 0.2 0.2 determination A B B A A A S S Connection resistance (after high temperature and high humidity test) Measured value (Ω) 5.4 6.8 6.3 5.6 6.0 7.5 0.5 0.5 determination C C C C C C S S

【Table 7】 Comparative example 1 2 transferability C A Capture rate D D Connect the resistor (just after installation) Measured value (Ω) 3.0 2.5 determination B B Connection resistance (after high temperature and high humidity test) Measured value (Ω) 10.3 11.5 determination D D

1: The first adhesive layer 2: The second adhesive layer 3: Adhesive ingredients 4: Conductive particles 5: The third adhesive layer 6: Matrix 7: Recess 9: Composition layer 10A, 10B: Adhesive film for circuit connection 21: The first circuit board 22: 1st electrode (circuit electrode) 23: 1st circuit component 24: Second circuit board 25: 2nd electrode (bump electrode) 26: Second circuit member 27: Connection part 100: Connection structure

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 arrangement example of conductive particles in the adhesive film for circuit connection of FIG. 1 . FIG. 3 is a schematic plan view showing an example of arrangement of conductive particles in the adhesive film for circuit connection 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 for producing the adhesive film for circuit connection of FIG. 1 . FIG. 6 is a view showing a modification of the cross-sectional shape of the recessed portion of the base body of FIG. 5 . FIG. 7 is a view showing a state in which conductive particles are arranged in the concave portion of the base of FIG. 5 . FIG. 8 is a schematic cross-sectional view showing one step of a method for producing 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 producing the adhesive film for circuit connection of FIG. 1 . FIG. 10 is a schematic cross-sectional view showing one step of the method of manufacturing the adhesive film for circuit connection of FIG. 1 . 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.

Claims (18)

A manufacturing method of an adhesive film for circuit connection, comprising the steps of: Prepare a matrix having a plurality of concave portions on the surface and at least a part of the plurality of concave portions arranged with conductive particles; Transferring the conductive particles to the composition layer by providing a composition layer containing a photocurable component and a first thermosetting component on the surface of the substrate; forming a first adhesive layer containing a plurality of the conductive particles, a cured product of the photocurable component, and the first thermosetting component by irradiating the composition layer with light; and A second adhesive layer containing a second thermosetting component is provided on one surface of the first adhesive layer. The method for producing an adhesive film for circuit connection according to claim 1, wherein The photocurable component includes a radically polymerizable compound and a photoradical polymerization initiator, The said 1st thermosetting component contains a cationically polymerizable compound and a thermal cationic polymerization initiator. The method for producing an adhesive film for circuit connection according to claim 2, wherein The said 1st thermosetting component contains the compound which has a cyclic ether group as the said cationically polymerizable compound. The method for producing an adhesive film for circuit connection according to claim 3, wherein The said 1st thermosetting component contains at least 1 sort(s) chosen from the group which consists of an oxetane compound and an alicyclic epoxy compound as the said cationically polymerizable compound. The method for producing an adhesive film for circuit connection according to any one of claim 2 to claim 4, wherein the photocurable component contains a compound represented by the following formula (1) as the radical polymerizable compound, [Chemical formula 1]

In 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 claim 2 to claim 5, wherein the photocurable component contains a compound represented by the following formula (I) as the initiation of the photoradical polymerization agent, [chemical formula 2]

In formula (I), R ² , R ³ and R ⁴ each independently represent a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an organic group including an aromatic hydrocarbon group. The method for producing an adhesive film for circuit connection according to any one of claim 2 to claim 6, wherein the first thermosetting component contains a compound represented by the following formula (II) or the following formula (III). A salt compound having a cation as the aforementioned thermal cationic polymerization initiator, [Chemical formula 3]

In formula (II), R ⁵ and R ⁶ each independently represent a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an organic group containing a substituted or unsubstituted aromatic hydrocarbon group, and R ⁷ represents a carbon number Alkyl of 1 to 6, [Chemical formula 4]

In formula (III), R ⁸ and R ⁹ each independently represent a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an organic group containing a substituted or unsubstituted aromatic hydrocarbon group, R ¹⁰ and R ¹¹ Each independently represents an alkyl group having 1 to 6 carbon atoms. The method for producing an adhesive film for circuit connection according to any one of claim 1 to claim 7, wherein The average particle size of the conductive particles is 1-30 μm, The C.V. value of the particle diameter of the conductive particles is 20% or less. The method for producing an adhesive film for circuit connection according to any one of claim 1 to claim 8, wherein The aforementioned conductive particles are solder particles. The method for producing an adhesive film for circuit connection according to claim 9, wherein The aforementioned solder particles include at least one selected from the group consisting of tin, tin alloys, indium, and indium alloys. The method for producing an adhesive film for circuit connection according to claim 10, wherein The aforementioned solder particles are selected from the group consisting of 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 At least one of the group consisting of alloys. The method for producing an adhesive film for circuit connection according to any one of claim 9 to claim 11, wherein A part of the surface of the said solder particle has a flat part. The method for producing an adhesive film for circuit connection according to claim 12, wherein The ratio of the diameter B of the flat portion to the diameter A of the solder particles, that is, B/A, satisfies the following formula: 0.01<B/A<1.0. The method for producing an adhesive film for circuit connection according to any one of claim 1 to claim 13, wherein In the case where a quadrilateral circumscribing the projected image of the conductive particle is made from two pairs of parallel lines, the distance between the opposing sides is taken as X and Y, and when Y<X, X and Y satisfy the following formula: 0.8<Y/X≤1.0. The method for producing an adhesive film for circuit connection according to any one of claim 1 to claim 14, wherein The plurality of recesses are formed in a predetermined pattern. An adhesive film for circuit connection, which contains conductive particles, and the adhesive film for circuit connection includes: a first adhesive layer containing a plurality of the conductive particles, a cured product of a photocurable component, and a first thermosetting component; and a second adhesive layer provided on the first adhesive layer and containing a second thermosetting component Element, At least a part of the plurality of conductive particles are arranged in a predetermined pattern when viewed from above the adhesive film for circuit connection, and in the longitudinal cross-section of the adhesive film for circuit connection, the adjacent conductive particles are separated from each other laterally. arrangement. A connection structure, which has: a first circuit member having a first electrode; a second circuit member having a second electrode; and A connecting portion comprising a cured body of the adhesive film for circuit connection according to claim 16, wherein the first electrode and the second electrode are electrically connected to each other via the conductive particles, and the first circuit member and the second circuit member are connected then. A method of manufacturing a connecting structure, comprising the steps of: The circuit connection according to claim 16 is arranged between the surface of the first circuit member having the first electrode, on which the first electrode is provided, and the surface of the second circuit member having the second electrode, on which the second electrode is provided. Adhesive film; and By heating the laminate including the first circuit member, the adhesive film for circuit connection, and the second circuit member in a state of being pressed in the thickness direction of the laminate, the first electrode and the second The electrodes are electrically connected to each other via the conductive particles, and the first circuit member and the second circuit member are bonded together.

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