WO2024042720A1

WO2024042720A1 - Adhesive film for circuit connection, connection structure, and methods for producing same

Info

Publication number: WO2024042720A1
Application number: PCT/JP2022/032258
Authority: WO
Inventors: 勝将宮地; 敏光森谷; 裕太山崎
Original assignee: 株式会社レゾナック
Priority date: 2022-08-26
Filing date: 2022-08-26
Publication date: 2024-02-29

Abstract

An adhesive film for circuit connection comprising a first adhesive layer having thermosettability, conductive particles partially embedded in one side of the first adhesive layer, and a second adhesive layer that has thermosettability and contacts one side of the first adhesive layer, the embedding rate of conductive particles in the first adhesive layer being 30-90% and the ratio of the flow rate of the second adhesive layer to the flow rate of the first adhesive layer being 1.20-4.00.

Description

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

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

Conventionally, various adhesive materials have been used to make circuit connections. For example, conductive particles in an adhesive can be used as an adhesive material for connecting a liquid crystal display and a tape carrier package (TCP), connecting a flexible printed wiring board (FPC) and a TCP, or connecting an FPC and a printed wiring board. An adhesive film for circuit connection is used in which . By using the circuit connection adhesive film, it is possible to adhere the circuit members to each other and to electrically connect the electrodes on the circuit members to each other via the conductive particles in the circuit connection portion.

By the way, in the field of precision electronic equipment in which circuit-connecting adhesive films are used, the density of circuits is increasing, and the electrode width and electrode spacing are becoming extremely narrow. For this reason, it is not always easy to efficiently trap conductive particles on the microelectrodes and obtain high connection reliability. On the other hand, for example, Patent Document 1 proposes a method in which conductive particles are unevenly distributed on one side of an adhesive film and the conductive particles are separated from each other.

International Publication No. 2005/54388

However, in the method of Patent Document 1, since the conductive particles flow when the circuit is connected, the conductive particles may aggregate between the electrodes, causing a short circuit.

One aspect of the present invention is to provide an adhesive film for circuit connection that can sufficiently secure conductive particle trapping properties while suppressing an increase in connection resistance. Another aspect of the present invention is to provide a method for manufacturing the circuit connection adhesive film. Moreover, some other aspects of the present invention aim to provide a connected structure using the above adhesive film for circuit connection and a method for manufacturing the same.

Some aspects of the present invention provide the following [1] to [16].

[1]
An adhesive film for circuit connection,
a first adhesive layer having thermosetting properties;
conductive particles partially embedded in one side of the first adhesive layer;
a second adhesive layer that has thermosetting properties and is in contact with the one surface of the first adhesive layer,
The embedding rate of the conductive particles in the first adhesive layer determined by the following formula (1) is 30 to 90%,
The circuit connection adhesive film was placed on the glass plate from the first adhesive layer side, and temporary pressure bonding was performed under the conditions of a pressure bonding temperature of 70° C., a bonding pressure of 0.1 MPa, and a bonding time of 1.0 s. The flow rate of each adhesive layer is defined by the following formula (2) when a glass plate is placed on the second adhesive layer and main pressure bonding is performed under the conditions of a pressure bonding temperature of 160°C, a pressure bonding pressure of 2 MPa, and a bonding time of 5 seconds. Then, the adhesive film for circuit connection has a ratio of the flow rate of the second adhesive layer to the flow rate of the first adhesive layer from 1.20 to 4.00.
Embedding rate (%) = H/L x 100... (1)
[In formula (1), H represents the length of embedding of the conductive particles in the first adhesive layer (unit: μm), and L represents the particle diameter of the conductive particles in the embedding direction (unit: μm). ) is shown. ]
Flow rate [%] = S _B / S _A × 100... (2)
[In formula (2), S _A represents the surface area of the adhesive layer before temporary pressure bonding, and S _B represents the area of the adhesive layer after main pressure bonding. ]

[2]
The adhesive film for circuit connection according to [1], wherein the first adhesive layer has a flow rate of 88 to 110%.

[3]
The adhesive film for circuit connection according to [1] or [2], wherein the first adhesive layer is a cured product of a precursor layer containing an external stimulation curable composition.

[4]
The adhesive film for circuit connection according to [3], wherein the externally stimulated curable composition has photocurability.

[5]
The adhesive film for circuit connection according to any one of [1] to [4], wherein at least some of the plurality of conductive particles are arranged in a predetermined pattern in plan view.

[6]
The average particle diameter of the conductive particles is 1.0 to 50.0 μm,
C. of the particle diameter of the conductive particles. V. The adhesive film for circuit connection according to any one of [1] to [5], which has a value of 25% or less.

[7]
The circuit connecting adhesive according to any one of [1] to [6], wherein the ratio of the thickness of the circuit connecting adhesive film to the average particle diameter of the conductive particles is 1.1 to 10.0. film.

[8]
The circuit connection according to any one of [1] to [7], wherein the ratio of the thickness of the second adhesive layer to the thickness of the first adhesive layer is 0.3 to 20.0. Adhesive film for.

[9]
The method for producing a circuit connection adhesive film according to any one of [1] to [8],
Step (I) of preparing a first adhesive film comprising the first adhesive layer and the conductive particles partially embedded in one side of the first adhesive layer;
a step (II) of providing the second adhesive layer on the one surface of the first adhesive layer,
In step (I), in a state where the conductive particles are partially embedded in one side of a precursor layer containing an external stimulus-curable composition, the precursor layer is cured by an external stimulus, and the first A method for producing an adhesive film for circuit connection, comprising a curing step of forming an adhesive layer.

[10]
The method for producing a circuit connection adhesive film according to [9], wherein in the curing step, the precursor layer is cured so that the flow rate of the first adhesive layer is 88 to 110%.

[11]
The external stimulation curable composition has photocurability,
The method for producing a circuit connection adhesive film according to [9] or [10], wherein in the curing step, the precursor layer is cured by light irradiation.

[12]
The step (I) further includes a transfer step of transferring the conductive particles from the substrate to the precursor layer by providing the precursor layer on the surface of the substrate on which a plurality of conductive particles are arranged. The method for producing a circuit connection adhesive film according to any one of [9] to [11], comprising:

[13]
For circuit connection according to [12], wherein the step (I) further includes, before the transfer step, a heating step of heating the layer containing the external stimulation curable composition at 50 to 70° C. for 3 to 60 minutes. Method of manufacturing adhesive film.

[14]
The circuit connection method according to [12] or [13], wherein the step (I) further includes, after the transfer step, a pressurizing step of applying pressure to the surface of the precursor layer to which the conductive particles have been transferred. Method of manufacturing adhesive film.

[15]
a first circuit member having a first electrode; a second circuit member having a second electrode electrically connected to the first electrode; and a first circuit member having a first electrode and a second electrode. and a connecting portion that electrically connects the circuit members to each other via conductive particles and adheres the first circuit member and the second circuit member,
A connected structure, wherein the connecting portion includes a cured product of the circuit connecting adhesive film according to any one of [1] to [8].

[16]
A surface of a first circuit member having a first electrode on which the first electrode is provided and a surface of a second circuit member having a second electrode on which the second electrode is provided. Placing the circuit connection adhesive film according to any one of [1] to [8] between them;
By heating a laminate including the first circuit member, the circuit connection adhesive film, and the second circuit member while pressing the laminate in the thickness direction, the first electrode and A method for manufacturing a connected structure, the method comprising electrically connecting the second electrode to each other via conductive particles, and bonding the first circuit member and the second circuit member. .

According to one aspect of the present invention, it is possible to provide an adhesive film for circuit connection that can sufficiently secure the ability to capture conductive particles while suppressing an increase in connection resistance. Moreover, according to another aspect of the present invention, it is possible to provide a method for manufacturing the above adhesive film for circuit connection. Further, according to some other aspects of the present invention, it is possible to provide a connected structure using the above adhesive film for circuit connection and a method for manufacturing the same.

FIG. 1 is a schematic plan view showing one embodiment of an adhesive film for circuit connection. FIG. 2 is a schematic cross-sectional view of the circuit-connecting adhesive film taken along line II-II in FIG. FIG. 3 is a partially enlarged cross-sectional view of the circuit-connecting adhesive film shown in FIG. 2. FIG. FIG. 4 is a schematic diagram for explaining one embodiment of a method for manufacturing a circuit connection adhesive film. FIG. 5 is a schematic diagram for explaining one embodiment of a method for manufacturing a circuit connection adhesive film. FIG. 6 is a schematic diagram for explaining one embodiment of a method for manufacturing a circuit connection adhesive film. FIG. 7 is a schematic diagram for explaining one embodiment of a method for manufacturing a circuit connection adhesive film. FIG. 8 is a schematic cross-sectional view showing one embodiment of a connected structure. FIG. 9 is a schematic diagram for explaining one embodiment of a method for manufacturing a connected structure.

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

<Adhesive film for circuit connection>
The circuit connection adhesive film includes conductive particles, a first thermosetting adhesive layer, and a thermosetting second adhesive layer. "For circuit connection" means used for connecting circuit members.

FIG. 1 is a schematic plan view showing one embodiment of a circuit connection adhesive film. A plurality of conductive particles 3 are present in the circuit connection adhesive film 10 shown in FIG. Among the plurality of conductive particles 3, adjacent conductive particles 3 exist in a state separated from each other. Therefore, it can be said that the circuit connection adhesive film 10 has a property (anisotropic conductivity) that is conductive in the pressure direction and maintains insulation in the non-pressure direction. The ratio (monodisperse rate) in which the conductive particles 3 exist in a state separated from other conductive particles 3 (monodisperse state) is preferably 90.0% or more, 93.0% or more, 95.0% or more. % or more, 97.0% or more, or 98.0% or more. The upper limit of the monodispersity rate is 100%. The higher the monodispersity, the easier it is to obtain a connected structure with excellent insulation reliability. Such a dispersed state can be formed by using a substrate on which the conductive particles 3 are arranged in a predetermined arrangement in the method for manufacturing the adhesive film 10 for circuit connection. Details will be described later.

At least some of the plurality of conductive particles 3 are arranged in a predetermined pattern in a plan view of the circuit connection adhesive film. The predetermined pattern (position and number of conductive particles 3) can be set depending on, for example, the shape, size, pattern, etc. of the electrode to be connected. In FIG. 1, the conductive particles 3 are arranged regularly and at approximately equal intervals over the entire area of the circuit-connecting adhesive film 10, but the arrangement of the conductive particles 3 is not limited to this example. . For example, in a plan view of the circuit-connecting adhesive film, the conductive particles are formed so that regions where a plurality of conductive particles 3 are regularly arranged and regions where conductive particles 3 are substantially absent are regularly formed. Particles 3 may be arranged. The fact that at least some of the plurality of conductive particles 3 are arranged in a predetermined pattern means that, for example, the circuit-connecting adhesive film 10 is inspected from above the main surface of the circuit-connecting adhesive film 10 using an electron microscope or the like. This can be confirmed by observation.

2 is a schematic cross-sectional view of the circuit-connecting adhesive film taken along line II-II in FIG. 1, and FIG. 3 is a partially enlarged view of the cross-section of the circuit-connecting adhesive film shown in FIG. 2. In FIGS. 2 and 3, the boundary between the first adhesive layer 1 and the second adhesive layer 2 is indicated by S. In FIG. 3, two contact points between the surface of the conductive particle 3 and the boundary S are indicated by C1 and C2, respectively, and a line segment (first virtual line segment) connecting the contact point C1 and the contact point C2 is indicated by l1. Further, among the line segments connecting two points on the surface of the conductive particles 3, a line segment (second virtual line segment) that is perpendicular to the line segment l1 and has the longest distance between the two points is indicated by l2. Furthermore, among the two points on the surface of the conductive particles 3 forming the line segment 12, the point of contact with the first adhesive layer 1 is indicated by C3, and the point of contact with the second adhesive layer 2 is indicated by C4. Further, the intersection of line segment l1 and line segment l2 is assumed to be C5.

As shown in FIGS. 2 and 3, the conductive particles 3 are partially embedded in one side of the first adhesive layer 1, and the second adhesive layer 2 is attached to the first adhesive layer 1. The conductive particles 3 are coated with the first adhesive layer 1 and the second adhesive layer 2 by being provided so as to be in contact with the one surface. The boundary S is located at a part where adjacent

conductive particles

3, 3 are separated. In addition, in FIG. 2, all of the plurality of conductive particles 3 are partially embedded in one side of the first adhesive layer 1, but as long as it does not impede the effects of the present invention, the first adhesive There may also be electrically conductive particles 3 completely embedded in layer 1 or in the second adhesive layer 2. The proportion of the conductive particles 3 completely buried in the first adhesive layer 1 or the second adhesive layer 2 may be, for example, 20% or less, 10% or less, or 5% or less. .

In the circuit connection adhesive film 10, the embedding rate (particle embedding rate) of the conductive particles 3 in the first adhesive layer 1 is 30 to 90%, and The flow rate ratio (hereinafter referred to as "flow ratio") of the second adhesive layer 2 is 1.20 to 4.00.

The particle embedding rate is determined by the following formula (1).
Particle embedding rate (%)=H/L×100...(1)

In formula (1), H represents the length of the conductive particles 3 embedded in the first adhesive layer 1 (unit: μm), and L represents the particle diameter of the conductive particles in the embedding direction (unit: μm). shows. In this specification, the direction perpendicular to the line segment l1 is defined as the embedding direction of the conductive particles 3, and the maximum value of the particle diameter in the embedding direction is defined as the particle diameter L in the embedding direction of the conductive particles. Therefore, the particle diameter L is equal to the length of the line segment l2. In addition, the maximum value of the length of the portion of the conductive particles 3 embedded in the first adhesive layer 1 (the length in the above-mentioned embedding direction) is calculated as the embedding length of the conductive particles 3 in the first adhesive layer 1. Let it be H. Therefore, the embedded length H of the conductive particles 3 in the first adhesive layer 1 is equal to the length of the line segment connecting the contact point C3 and the intersection point C5.

The particle embedding ratio can be measured by, for example, observing a longitudinal section (a section in the thickness direction) of the circuit-connecting adhesive film using a scanning electron microscope (SEM). Specifically, for example, after obtaining cross-sectional images (SEM images) by observing 100 arbitrary cross-sections of a circuit-connecting adhesive film at a magnification of 5000 times using a scanning electron microscope (SEM), each cross-sectional image is In any 20 μm x 15 μm area within, the embedding rate of conductive particles having the maximum particle diameter L in the embedding direction and the conductive particles having a particle diameter L of 0.85 to 1.00 times that of the conductive particles. The average value of these values is determined as the embedding rate of conductive particles in each cross section. Next, the average value of the embedding ratio of conductive particles in the ten calculated cross sections is determined, and this is taken as the embedding ratio of conductive particles in the circuit connection adhesive film (particle embedding ratio).

The flow rate of each adhesive layer (first adhesive layer 1 and second adhesive layer 2) is determined by placing the adhesive film 10 for circuit connection on a glass plate from the first adhesive layer 1 side, and pressing it. After performing temporary pressure bonding at a temperature of 70° C., a pressure bonding pressure of 0.1 MPa, and a pressure bonding time of 1.0 s, a glass plate was placed on the second adhesive layer 2, and a pressure bonding temperature of 160° C., a pressure bonding pressure of 2 MPa, and a pressure bonding time of 1.0 seconds were performed. This is the flow rate when main pressure bonding is performed under the condition of 5 seconds, and is defined by the following formula (2).
Flow rate [%] = S _B / S _A × 100... (2)

In formula (2), S _A represents the surface area of the adhesive layer before temporary pressure bonding, and S _B represents the area of the adhesive layer after main pressure bonding.

Specifically, the flow rate of each of the adhesive layers described above can be measured by the following procedures (I) to (IV).
(I) Punch out the adhesive film for circuit connection in the thickness direction with the base material affixed on both main surfaces of the adhesive film for circuit connection, and form a disc-shaped evaluation adhesive with radius r. Get the film.
(II) After peeling off the base material on the first adhesive layer side from the adhesive film for evaluation, place the adhesive film for evaluation on the first glass plate from the first adhesive layer side, and From the adhesive layer side, thermocompression bonding is performed under conditions of a compression temperature of 70° C., a compression pressure of 0.1 MPa, and a compression time of 1.0 s to obtain a temporarily fixed body.
(III) After peeling off the base material on the second adhesive layer side from the temporary fixing body, place the second glass plate on the second adhesive layer, and press from the second adhesive layer side at a pressure bonding temperature of 160. ℃, a compression pressure of 2 MPa, and a compression time of 5 seconds to obtain a crimped body.
(IV) Adhesion area S _B1 (unit: mm ² ) between the surface on the first adhesive layer side and the first glass plate in the crimped body and the surface on the second adhesive layer side and the second glass plate The adhesive area S _B2 (unit: mm ² ) with the first adhesive layer is determined and the flow rate of the first adhesive layer and the second adhesive layer are determined based on the following formulas (2-1) and (2-2). Calculate the flow rate of
Flow rate of first adhesive layer [%] = S _B1 / (r ² π) × 100 (2-1)
Flow rate of second adhesive layer [%] = S _B2 / (r ² π) × 100 (2-2)

When the particle embedding ratio and flow ratio are within the above ranges, the flow of the conductive particles during thermocompression bonding is suppressed, so that the trapping performance of the conductive particles can be sufficiently ensured. Further, when the particle embedding ratio and the flow ratio are within the above ranges, an increase in connection resistance due to the presence of adhesive between the conductive particles and the connection portion is suppressed. Therefore, the circuit connection adhesive film 10 adheres the first circuit member having the first electrode and the second circuit member having the second electrode, and also connects the first electrode and the second electrode. It is suitably used for electrically connecting two parts to each other.

The particle embedding rate in the first adhesive layer may be 38% or more, 45% or more, 52% or more, or 60% or more from the viewpoint of further increasing the capture rate of the conductive particles 3. The particle embedding rate in the first adhesive layer may be 85% or less, 75% or less, 65% or less, 55% or less, or 48% or less from the viewpoint of further reducing connection resistance. From these viewpoints, the particle embedding rate in the first adhesive layer is 38-85%, 45-75%, 52-75%, 60-75%, 30-65%, 30-55%, or 30%. It may be between 48% and 48%.

The flow ratio may be 1.40 or more, 1.50 or more, 1.60 or more, or 1.70 or more from the viewpoint of increasing the capture rate of the conductive particles 3 and reducing the connection resistance. good. From the viewpoint of increasing the connection reliability of the connected structure, the flow ratio may be 3.60 or less, 2.80 or less, 2.20 or less, or 1.70 or less. From these points of view, the flow ratio is 1.40 to 3.60, 1.50 to 2.80, 1.60 to 2.80, 1.70 to 2.80, 1.20 to 2.20, or 1. It may be between .20 and 1.70. The above flow ratio is achieved, for example, by using the first adhesive layer 1 as a cured product of a precursor layer containing an external stimulation curable composition.

From the viewpoint of further reducing connection resistance, the flow rate of the first adhesive layer 1 may be 88% or more, 92% or more, 95% or more, or 100% or more. The flow rate of the first adhesive layer 1 may be 110% or less, 108% or less, or 106% or less from the viewpoint of further increasing the capture rate of the conductive particles 3. From these points of view, the flow rate of the first adhesive layer 1 may be 88-110%, 92-110%, 95-108% or 100-108%.

From the viewpoint of further reducing connection resistance, the flow rate of the second adhesive layer 2 may be 120% or more, 150% or more, 160% or more, or 210% or more. The flow rate of the second adhesive layer 2 may be 440% or less, 400% or less, 350% or less, 300% or less, 250% or less, from the viewpoint of further increasing the capture rate of the conductive particles 3. Or it may be 200% or less. From these points of view, the flow rate of the second adhesive layer 2 may be 120-440%, 150-400%, 160-400%, 210-350%, 120-300%, 120-250%. Or it may be 120 to 200%.

The first adhesive layer 1 and the second adhesive layer 2 are formed on the surface of the circuit connecting adhesive film 10 (the surface opposite to the second adhesive layer 2 side in the first adhesive layer 1, and The thickness may be such that the conductive particles 3 are not exposed from the surface of the second adhesive layer 2 opposite to the first adhesive layer 1 side.

The thickness d1 (distance indicated by d1 in FIG. 2) 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, and 50.0 μm or less, 40 μm or more. .0 μm, 30.0 μm or less, 20.0 μm or less, 10.0 μm or less, 5.0 μm or less, or 3.0 μm or less, 0.5 to 50.0 μm, 1.0 to 40.0 μm, 2. It may be 0-30.0 μm, 1.0-20.0 μm, 1.0-10.0 μm, 1.0-5.0 μm or 1.0-3.0 μm. When the thickness d1 of the first adhesive layer 1 is within the above range, it is easy to achieve both lower connection resistance and higher conductive particle capture rate.

The thickness d2 (distance indicated by d2 in FIG. 2) of the second adhesive layer 2 may be, for example, 0.5 μm or more, 1.0 μm or more, 2.0 μm or more, or 3.0 μm or more, and may be 50 μm or more, for example. .0 μm or less, 40.0 μm or less, 30.0 μm or less, 20.0 μm or less, 10.0 μm or less, or 5.0 μm or less, 0.5 to 50.0 μm, 1.0 to 40.0 μm, 2 0 to 30.0 μm, 3.0 to 20.0 μm, 3.0 to 10.0 μm, or 3.0 to 5.0 μm. When the thickness d2 of the second adhesive layer 2 is within the above range, the space between the electrodes can be sufficiently filled to seal the electrodes, and better connection reliability is likely to be obtained.

The ratio of the thickness d2 of the second adhesive layer 2 to the thickness d1 of the first adhesive layer 1 may be 0.3 or more from the viewpoint of connection reliability of the connected structure, It may be 1.0 or more, 2.0 or more, or 2.5 or more. The ratio of the thickness d2 of the second adhesive layer 2 to the thickness d1 of the first adhesive layer 1 may be 20.0 or less from the viewpoint of the capture rate of conductive particles, and 15. It may be 0 or less, 12.0 or less, 10.0 or less, 6.0 or less, or 4.0 or less. From these viewpoints, the ratio of the thickness d2 of the second adhesive layer 2 to the thickness d1 of the first adhesive layer 1 is determined from the viewpoint of connection reliability and low resistance of the connected structure. It may be 0.3 to 20.0, 1.0 to 15.0, 2.0 to 12.0, 2.0 to 10.0, 2.0 to 6.0, 2.0 to 4. It may be 0 or 2.5 to 10.0.

The thickness of the circuit connection adhesive film 10 may be, for example, 2.0 μm or more, 3.0 μm or more, or 4.0 μm or more, and 100.0 μm or less, 80.0 μm or less, 60.0 μm or less, or 40.0 μm or less. May be 0 μm or less, 20.0 μm or less, or 10.0 μm or less, 2.0 to 100.0 μm, 3.0 to 80.0 μm, 4.0 to 60.0 μm, 4.0 to 40.0 μm, 4 It may be between .0 and 20.0 μm or between 4.0 and 10.0 μm.

The thickness d1 of the first adhesive layer 1, the thickness d2 of the second adhesive layer 2, and the thickness of the circuit connection adhesive film 10 are, for example, such that the circuit connection adhesive film 10 is attached to two sheets of glass. (thickness: approximately 1 mm) and 100 g of bisphenol A epoxy resin (product name: jER811, manufactured by Mitsubishi Chemical Corporation) and 10 g of a curing agent (product name: Epomount hardening agent, manufactured by Refinetech Co., Ltd.). After casting with a resin composition of can.

Next, the adhesive composition constituting the first adhesive layer 1 and the second adhesive layer 2 and the conductive particles 3 will be explained. Hereinafter, the adhesive composition forming the first adhesive layer 1 will be referred to as a "first adhesive composition," and the adhesive composition forming the second adhesive layer 2 will be referred to as a "second adhesive composition." agent composition.

(First adhesive composition)
The first adhesive composition has thermosetting properties. That is, the first adhesive composition contains at least a thermosetting component.

The first adhesive composition is, for example, a cured product of an external stimulation curable composition obtained by curing an external stimulation curable composition. Since the cured product of the external stimulation curable composition has thermosetting properties, it can also be called a partially cured product. External stimulus curable compositions have the property of being cured by external stimuli such as heat, light, stress, and the like. The external stimulation curable composition is, for example, a composition having thermosetting properties and photocuring properties. By photocuring a thermosetting and photocurable composition, a thermosetting cured product (cured product of an external stimulation curable composition) can be obtained. When the external stimulation composition has thermosetting and photocurable properties, the external stimulation composition includes at least a thermosetting component and a photocurable component, and the first adhesive composition has a photocurable composition. It contains at least a cured product of the components and a thermosetting component.

[Thermosetting component]
A thermosetting component is a component that is flowable upon connection and hardens upon heating. The thermosetting component includes, for example, a polymerizable compound and a thermal polymerization initiator. The polymerizable compound may be a radically polymerizable compound, a cationically polymerizable compound, or an anionically polymerizable compound. Similarly, the thermal polymerization initiator may be a thermal radical polymerization initiator, a thermal cationic polymerization initiator, or a thermal anionic polymerization initiator. From the viewpoint of being more effective in reducing connection resistance, the polymerizable compound may be a cationic polymerizable compound, and the thermal polymerization initiator may be a thermal cationic polymerization initiator.

The cationic polymerizable compound may be a compound having a cyclic ether group from the viewpoint of further improving the connection resistance reduction effect and providing superior connection reliability. Among the compounds having a cyclic ether group, when at least one selected from the group consisting of alicyclic epoxy compounds and oxetane compounds is used, the effect of reducing connection resistance tends to be further improved. The cationic polymerizable compound may contain both an alicyclic epoxy compound and an oxetane compound from the viewpoint of easily obtaining a desired melt viscosity.

The alicyclic epoxy compound can be used without particular limitation as long as it is a compound having an alicyclic epoxy group (for example, an epoxycyclohexyl group). The alicyclic epoxy compound may be, for example, an epoxy compound having an epoxy equivalent of 100 to 300 g/eq. The epoxy equivalent is determined in accordance with JIS K 7236.

Commercially available alicyclic epoxy compounds include Celoxide 8010 (trade name, Bi-7-oxabicyclo[4.1.0]heptane, manufactured by Daicel Corporation), for example, EHPE3150, EHPE3150CE, Celoxide 2021P, Celoxide 2081 (trade name, manufactured by Daicel Corporation) and the like.

The oxetane compound can be used without particular limitation as long as it has an oxetanyl group. Commercially available oxetane compounds include, for example, ETERNACOLL OXBP (trade name, 4,4'-bis[(3-ethyl-3-oxetanyl)methoxymethyl]biphenyl, manufactured by Ube Industries, Ltd.), OXSQ, OXT-121, Examples include OXT-221, OXT-101, OXT-212 (trade name, manufactured by Toagosei Co., Ltd.).

As the compound having a cyclic ether group, epoxy compounds other than alicyclic epoxy compounds may be used. Specifically, for example, epoxy compounds having an aromatic hydrocarbon group such as bisphenol A type epoxy resin and bisphenol F type epoxy resin (for example, Mitsubishi Chemical Corporation's product name "jER1010", Nippon Steel Chemical & Materials) It is also possible to use a product such as "TOPR-400" (trade name, manufactured by Co., Ltd.). The epoxy equivalent of the epoxy compound having an aromatic hydrocarbon group may be 100 g/eq or more (for example, 100 to 3500 g/eq), or 150 g/eq or more (for example, 150 to 3500 g/eq). An epoxy compound having an aromatic hydrocarbon group may be used in combination with an alicyclic epoxy compound from the viewpoint of further improving the effect of reducing connection resistance and providing superior connection reliability.

The thermal cationic polymerization initiator is, for example, a compound (thermal latent cation generator) that can generate an acid or the like upon heating to initiate polymerization. The thermal cationic polymerization initiator may be a salt compound composed of a cation and an anion. Thermal cationic polymerization initiators include, 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 ^- , SbF ₆ Examples include onium salts such as sulfonium salts, phosphonium salts, ammonium salts, diazonium salts, iodonium salts, anilinium salts, and pyridinium salts having anions such as ^- and AsF ₆ ^- . These may be used alone or in combination.

From the viewpoint of rapid curing, the thermal cationic polymerization initiator 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). It will be done. The anion containing boron as a constituent element may be BR ₄ ⁻ , and more specifically may be tetrakis(pentafluorophenyl)borate.

From the viewpoint of storage stability, the thermal cationic polymerization initiator may be a salt compound having a cation represented by the following formula (I) or the following formula (II).

In formula (I), R ¹ and R ² 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 ³ represents an alkyl group having 1 to 6 carbon atoms.

Specific examples of compounds having a cation represented by formula (I) include 1-naphthylmethyl-p-hydroxyphenylsulfonium hexafluoroantimonate (manufactured by Sanshin Kagaku Co., Ltd., SI-60 base agent).

In formula (II), R ⁴ and R ⁵ 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 ⁶ and R ⁷ each independently represent an alkyl group having 1 to 6 carbon atoms.

Specific examples of compounds having a cation represented by formula (II) include YH-MS20 (trade name, manufactured by Yokohama Rubber Co., Ltd.), CXC-1821 (trade name, manufactured by King Industries), and the like.

The content of the thermal cationic polymerization initiator is, for example, 0.1 to 25 parts by mass, 0.1 to 25 parts by mass, based on 100 parts by mass of the cationic polymerizable compound, from the viewpoint of ensuring the formability and curability of the adhesive film. It may be 20 parts by weight, 1 to 18 parts by weight, 3 to 15 parts by weight, or 5 to 12 parts by weight.

The content of the thermosetting component (for example, the total content of the polymerizable compound and the thermal polymerization initiator) is based on the total mass of the first adhesive composition, from the viewpoint of ensuring the curability of the adhesive film. For example, it may be 3% by mass or more, 5% by mass or more, 10% by mass or more, or 15% by mass or more. From the viewpoint of ensuring adhesive film formability, the content of the thermosetting component is, for example, 70% by mass or less, 60% by mass or less, 50% by mass or less, or 40% by mass or less, based on the total mass of the adhesive composition. It may be less than % by mass. From these viewpoints, the content of the thermosetting component is, for example, 3 to 70% by mass, 5 to 60% by mass, 10 to 50% by mass, or 15 to 50% by mass, based on the total mass of the first adhesive composition. It may be 40% by mass. From the same viewpoint as above, the total content of the cationic polymerizable compound and the thermal cationic polymerization initiator may be within the above range.

[Photocurable component]
A photocurable component is a component that is cured by light (actinic rays). The photocurable component includes, for example, a polymerizable compound and a photopolymerization initiator. The polymerizable compound may be a radically polymerizable compound, a cationically polymerizable compound, or an anionically polymerizable compound. Similarly, the photopolymerization initiator may be a radical photopolymerization initiator, a cationic photopolymerization initiator, or an anionic photopolymerization initiator. The type of photocurable component may be determined by considering the combination with the thermosetting component. For example, when the thermosetting component is a cationically polymerizable component, the photocurable component may be a radically polymerizable component. That is, when the thermosetting component contains a cationically polymerizable compound and a thermal cationic polymerization initiator, the photocurable component may contain a radically polymerizable compound and a photoradical polymerization initiator.

Examples of radically polymerizable compounds include (meth)acrylate compounds, maleimide compounds, citraconimide compounds, nadimide compounds, and the like. From the viewpoint that it is easier to obtain the first adhesive layer with the above flow rate, the photocurable component may contain a (meth)acrylate compound, and from the viewpoint that it is easier to obtain the first adhesive layer with the above flow rate. The photocurable component may contain a polyfunctional (meth)acrylate compound having two or more (meth)acryloyl groups.

Examples of polyfunctional (meth)acrylates include ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, and polyethylene glycol di(meth)acrylate. ) acrylate, propylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, tetrapropylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, ethoxylated polypropylene glycol Di(meth)acrylate, 1,3-butanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 3-methyl-1,5-pentanediol di(meth)acrylate (meth)acrylate, 1,6-hexanediol di(meth)acrylate, 2-butyl-2-ethyl-1,3-propanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1 Aliphatic ( meth)acrylate; ethoxylated bisphenol A type di(meth)acrylate, propoxylated bisphenol A type di(meth)acrylate, ethoxylated propoxylated bisphenol A type di(meth)acrylate, ethoxylated bisphenol F type di(meth)acrylate, Propoxylated bisphenol F type di(meth)acrylate, ethoxylated propoxylated bisphenol F type di(meth)acrylate, ethoxylated fluorene type di(meth)acrylate, propoxylated fluorene type di(meth)acrylate, ethoxylated propoxylated fluorene type Aromatic (meth)acrylates such as di(meth)acrylate, trimethylolpropane tri(meth)acrylate, ethoxylated trimethylolpropane tri(meth)acrylate, propoxylated trimethylolpropane tri(meth)acrylate, ethoxylated propoxylated tri(meth)acrylate Methylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, ethoxylated pentaerythritol tri(meth)acrylate, propoxylated pentaerythritol tri(meth)acrylate, ethoxylated propoxylated pentaerythritol tri(meth)acrylate, pentaerythritol Tetra(meth)acrylate, Ethoxylated Pentaerythritol Tetra(meth)acrylate, Propoxylated Pentaerythritol Tetra(meth)acrylate, Ethoxylated Propoxylated Pentaerythritol Tetra(meth)acrylate, Ditrimethylolpropane Tetraacrylate, Dipentaerythritol Hexa(meth)acrylate ) aliphatic (meth)acrylates such as acrylates; aromatics such as bisphenol-type epoxy (meth)acrylates (e.g. bisphenol A-type epoxy (meth)acrylates), phenol novolac-type epoxy (meth)acrylates, cresol novolak-type epoxy (meth)acrylates, etc. Examples include group epoxy (meth)acrylates.

The content of polyfunctional (meth)acrylate is 40 to 100% by mass based on the total mass of the polymerizable compound in the photocurable component, from the viewpoint of achieving both the effect of reducing connection resistance and suppressing particle flow. It may be 50 to 100% by weight or 60 to 100% by weight.

From the viewpoint that it is easier to obtain the first adhesive layer with the above flow rate, the photocurable component may contain epoxy (meth)acrylate, and from the viewpoint that it is easier to obtain the first adhesive layer with the above flow rate. , the photocurable component may include aromatic epoxy (meth)acrylate. The content of epoxy (meth)acrylate may be, for example, 40 to 100% by weight, 50 to 100% by weight, or 60 to 100% by weight, based on the total weight of the polymerizable compounds in the photocurable component.

From the viewpoint that the first adhesive layer having the above flow rate can be easily obtained, the photocurable component contains a (meth)acrylate compound having a crosslinked structure such as a tricyclodecane structure or a norbornane structure, and/or an aromatic structure. It's okay to be there. The content of the (meth)acrylate compound having a crosslinked structure such as a tricyclodecane structure or a norbornane structure, and/or an aromatic structure is, for example, 40% based on the total mass of the polymerizable compound in the photocurable component. It may be ~100% by weight, 50-100% by weight, or 60-100% by weight.

The photo-radical polymerization initiator is a photo-polymerization initiator that generates radicals upon irradiation with light (for example, ultraviolet light) having a wavelength within the range of 150 to 750 nm. The photo-radical polymerization initiator has an oxime ester structure, a bisimidazole structure, an acridine structure, an α-aminoalkylphenone structure, an aminobenzophenone structure, an N-phenylglycine structure, an acylphosphine oxide structure, a benzyl dimethyl ketal structure, and an α-hydroxyalkylphenone structure. It may be a compound having a structure such as a structure. The photoradical polymerization initiator is selected from the group consisting of an oxime ester structure, an α-aminoalkylphenone structure, and an acylphosphine oxide structure, from the viewpoint of easily obtaining the desired melt viscosity and from the viewpoint of being more effective in reducing connection resistance. It may be a compound having at least one type of structure.

Specific examples of compounds having an oxime ester structure include 1-phenyl-1,2-butanedione-2-(o-methoxycarbonyl)oxime, 1-phenyl-1,2-propanedione-2-(o-methoxycarbonyl) ) oxime, 1-phenyl-1,2-propanedione-2-(o-ethoxycarbonyl)oxime, 1-phenyl-1,2-propanedione-2-o-benzoyloxime, 1,3-diphenylpropanetrione- 2-(o-ethoxycarbonyl)oxime, 1-phenyl-3-ethoxypropanetrione-2-(o-benzoyl)oxime, 1,2-octanedione, 1-[4-(phenylthio)phenyl-,2-( o-benzoyloxime)], ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-,1-(o-acetyloxime), and the like.

Specific examples of compounds having an α-aminoalkylphenone structure include 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1 -morpholinophenyl)-butanone-1 and the like.

Specific examples of compounds having an acylphosphine oxide structure include bis(2,6-dimethoxybenzoyl)-2,4,4-trimethyl-pentylphosphine oxide, bis(2,4,6,-trimethylbenzoyl)-phenylphosphine oxide, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, and the like.

The content of the photoradical polymerization initiator is, for example, 0.1 to 10 parts by mass, 0.1 to 10 parts by mass, based on 100 parts by mass of the radically polymerizable compound, from the viewpoint of easily obtaining the first adhesive layer having the above flow rate. It may be 3 to 7 parts by weight or 0.5 to 5 parts by weight.

The content of the photocurable component (for example, the total content of the polymerizable compound and the photopolymerization initiator) is determined based on the total content of the first adhesive composition from the viewpoint of easily obtaining the first adhesive layer having the above flow rate. Based on the mass, it may be, for example, 3% by mass or more, 5% by mass or more, or 10% by mass or more. The content of the photocurable component is, for example, 50% by mass or less, 40% by mass or less based on the total mass of the adhesive composition, from the viewpoint of easily obtaining the desired melt viscosity and from the viewpoint of being more effective in reducing connection resistance. It may be less than 30% by mass or less than 30% by mass. From these viewpoints, the content of the thermosetting component is, for example, 3 to 50% by mass, 5 to 40% by mass, or 10 to 30% by mass, based on the total mass of the first adhesive composition. good. From the same viewpoint as above, the total content of the radically polymerizable compound and the photoradical polymerization initiator may be within the above range.

[Other ingredients]
The first adhesive composition may further contain, for example, a thermoplastic resin, a filler, a coupling agent, and the like.

The thermoplastic resin contributes to improving the film-forming properties of the adhesive film. Examples of the thermoplastic resin include phenoxy resin, polyester resin, polyamide resin, polyurethane resin, polyester urethane resin, acrylic rubber, and epoxy resin (solid at 25° C.). Examples of the above phenoxy resins include fluorene type phenoxy resins (epoxy resins containing a fluorene skeleton), bisphenol A/bisphenol F copolymerized phenoxy resins (phenoxy resins containing a bisphenol A skeleton and a bisphenol F skeleton), and the like. . Among these, when using a bisphenol A/bisphenol F copolymerized phenoxy resin, there is a tendency to easily achieve both properties derived from a thermoplastic resin (for example, film-forming properties) and curability of the connection portion in the connected structure. These may be used alone or in combination.

The weight average molecular weight (Mw) of the thermoplastic resin 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 expulsion during connection (mounting). Note that Mw means a value measured by gel permeation chromatography (GPC) and converted using a standard polystyrene calibration curve.

The content of the thermoplastic resin may be, for example, 1% by mass or more, 5% by mass or more, 10% by mass or more, or 20% by mass or more, based on the total mass of the first adhesive composition, and may be 70% by mass or more. % or less, 60% by weight or less, 50% by weight or less, or 40% by weight or less, and may be 1 to 70% by weight, 5 to 60% by weight, 10 to 50% by weight, or 20 to 40% by weight.

Examples of the filler include non-conductive fillers (for example, non-conductive particles). The filler may be either an inorganic filler or an organic filler. Examples of the inorganic filler include metal oxide particles such as silica particles, alumina particles, silica-alumina particles, titania particles, and zirconia particles; inorganic particles such as metal nitride particles. Examples of the organic filler include organic fine particles such as silicone fine particles, methacrylate/butadiene/styrene fine particles, acrylic/silicone fine particles, polyamide fine particles, and polyimide fine particles. From the viewpoint of connection reliability of the connected structure, the filler may be fine silica particles, or fine silica particles whose surface has been treated with a silane compound such as phenyltrimethoxysilane or octylsilane.

The average particle size of the filler may be 0.25 to 20 μm. Here, the average particle diameter of the filler is a value measured by a flow type particle image analyzer (for example, FPIA-3000S manufactured by CIMEX Corporation).

The content of the filler may be, for example, 0.1 to 10% by mass based on the total mass of the first adhesive composition.

Examples of coupling agents include silane coupling agents (γ-glycidoxypropyltrimethoxysilane, 2-( Examples include silane compounds such as 3,4-epoxycyclohexyl)ethyltrimethoxysilane, tetraalkoxysilane, tetraalkoxy titanate derivatives, and polydialkyl titanate derivatives. Among these, when a silane coupling agent having an organic functional group is used, the adhesiveness of the first adhesive composition tends to be further improved. The content of the coupling agent may be, for example, 0.1 to 10% by weight based on the total weight of the first adhesive composition.

The first adhesive composition may further contain a softener, an accelerator, a deterioration inhibitor, a colorant, a flame retardant, a thixotropic agent, etc. as other components. The content of these components may be, for example, 0.1 to 10% by mass based on the total mass of the first adhesive composition.

(Second adhesive composition)
The second adhesive composition has thermosetting properties. That is, the second adhesive composition contains at least a thermosetting component. As the thermosetting component, those exemplified as the thermosetting component contained in the first adhesive composition can be used.

The thermosetting component may contain a cationic polymerizable compound and a thermal cationic polymerization initiator from the viewpoint of being more effective in reducing connection resistance. The content of the thermal cationic polymerization initiator in the second adhesive composition may be the same as the content of the thermal cationic polymerization initiator in the first adhesive composition.

The cationic polymerizable compound may contain both an alicyclic epoxy compound and an oxetane compound from the viewpoint of easily obtaining a desired melt viscosity. Furthermore, from the viewpoint of further improving the connection resistance reduction effect and providing superior connection reliability, an alicyclic epoxy compound and an epoxy compound having an aromatic hydrocarbon group may be used in combination. Furthermore, from the viewpoint of connection reliability of the connected structure, a rubber-modified alicyclic epoxy compound may be used.

The content of the thermosetting component (for example, the total content of the polymerizable compound and the thermal polymerization initiator) is based on the total mass of the second adhesive composition, from the viewpoint of ensuring the curability of the adhesive film. For example, it may be 3% by mass or more, 5% by mass or more, 10% by mass or more, or 15% by mass or more. From the viewpoint of ensuring adhesive film formability, the content of the thermosetting component is, for example, 70% by mass or less, 60% by mass or less, 50% by mass or less, or 40% by mass or less, based on the total mass of the adhesive composition. It may be less than % by mass. From these viewpoints, the content of the thermosetting component is, for example, 3 to 70% by mass, 5 to 60% by mass, 10 to 50% by mass, or 15 to 50% by mass, based on the total mass of the first adhesive composition. It may be 40% by mass. From the same viewpoint as above, the total content of the cationic polymerizable compound and the thermal cationic polymerization initiator may be within the above range.

Similarly to the first adhesive composition, the second adhesive composition may further contain components such as a thermoplastic resin, a filler, and a coupling agent. As these components, those exemplified as components that can be included in the first adhesive composition can be used.

When using a fluorene-type phenoxy resin among thermoplastic resins, there is a tendency to achieve both film formability and connection reliability of the connected structure. The content of the thermoplastic resin may be, for example, 1% by mass or more, 5% by mass or more, 10% by mass or more, or 20% by mass or more, based on the total mass of the second adhesive composition, and may be 70% by mass or more. % or less, 60% by weight or less, 50% by weight or less, or 40% by weight or less, and may be 1 to 70% by weight, 5 to 60% by weight, 10 to 50% by weight, or 20 to 40% by weight.

From the viewpoint of connection reliability of the connected structure, the filler may be fine silica particles, or fine silica particles whose surface has been treated with a silane compound such as phenyltrimethoxysilane or octylsilane. The content of the filler may be, for example, 0.1 to 10% by weight, based on the total weight of the second adhesive composition.

Among the coupling agents, when a silane coupling agent having an organic functional group is used, the adhesiveness of the second adhesive composition tends to be further improved. The content of the coupling agent may be, for example, 0.1 to 10% by weight based on the total weight of the second adhesive composition.

The second adhesive composition may further contain a softener, an accelerator, a deterioration inhibitor, a colorant, a flame retardant, a thixotropic agent, and the like. The content of these components may be, for example, 0.1 to 10% by mass based on the total mass of the second adhesive composition.

The second adhesive composition may contain ε-caprolactam as a thermosetting reaction rate regulator. The content of ε-caprolactam may be, for example, 0.005 to 0.1% by mass based on the total mass of the second adhesive composition.

The second adhesive composition may contain tributylborate as an additive. Tributylborate can function as, for example, a viscosity modifier. The content of tributylborate may be, for example, 0.1 to 2.0% by weight based on the total weight of the second adhesive composition.

(conductive particles)
The conductive particles 3 are particles having conductivity. As the conductive particles 3, metal particles made of metal such as Au, Ag, Ni, Cu, and solder, conductive carbon particles made of conductive carbon, and the like can be used. The conductive particles 3 may be coated conductive particles comprising a core containing non-conductive glass, ceramic, plastic (polystyrene, etc.), and a coating layer containing the above-mentioned metal or conductive carbon and covering the core. . Among these, when using metal particles formed of a heat-melting metal or coated conductive particles comprising a core containing plastic and a coating layer containing metal or conductive carbon and covering the core, the first It becomes easy to deform the adhesive layer by heating or applying pressure. Therefore, when electrically connecting the electrodes, the contact area between the electrodes and the conductive particles can be increased, and the conductivity between the electrodes can be further improved.

The conductive particles 3 may be insulating coated conductive particles that include the above metal particles, conductive carbon particles, or coated conductive particles and an insulating layer that includes an insulating material such as a resin and covers the surface of the particles. . When the conductive particles 3 are insulating coated conductive particles, even if the conductive particle content is large, the surface of the particles is coated with resin, so it is possible to suppress the occurrence of short circuits due to contact between the conductive particles, and , it is also possible to improve the insulation between adjacent electrode circuits.

From the viewpoint of availability of raw materials and formation of a connected structure required in the market, the average particle diameter of the conductive particles 3 may be 1.0 to 50.0 μm. In addition, from the viewpoint of connection reliability of the structure, the particle diameter of the conductive particles 3 is C. V. The value may be 25% or less. From these viewpoints, the conductive particles 3 have an average particle diameter of 1.0 to 50.0 μm, and a particle diameter of C. V. The particles may have a value of 25% or less. In this specification, the average particle diameter of the conductive particles is the average value of the particle diameters in the embedding direction of the conductive particles measured by the method described above, and the C.I. V. The value is the C. V. It is a value. Particle size C. V. The value is a value calculated by dividing the standard deviation of particle diameter by the average particle diameter and multiplying by 100, and is a parameter indicating the degree of variation in particle diameter. Particle size C. V. A small value means that there is little variation in particle size. C. of the average particle diameter of the conductive particles and the particle diameter of the conductive particles. V. The value can be measured by observing a longitudinal section (cross section in the thickness direction) of the circuit-connecting adhesive film using a scanning electron microscope (SEM) in the same manner as the method for measuring the particle embedding rate.

The average particle diameter of the conductive particles 3 may be 2.0 μm or more or 4.0 μm or more from the viewpoint of lowering resistance. The average particle diameter of the conductive particles 3 may be 40.0 μm or less or 25.0 μm or less from the viewpoint of connection reliability of the connected structure. From these viewpoints, the average particle diameter of the conductive particles 3 may be 2.0 to 40.0 μm or 4.0 to 25.0 μm.

C. of particle diameter of conductive particles 3 V. The value may be 20% or less or 15% or less from the viewpoint of connection reliability of the connection structure. C. of the particle diameter of the conductive particles 3 V. The lower limit of the value is preferably as small as possible, and may be 0%, 1% or 3%. C. of the particle diameter of the conductive particles 3 V. The value may be, for example, 0-25%, 1-20% or 3-15%.

The ratio of the thickness of the circuit-connecting adhesive film 10 to the average particle diameter of the conductive particles 3 may be 1.1 or more from the viewpoint of not exposing the conductive particles 3 from the surface of the circuit-connecting adhesive film 10. It may be 1.5 or more, 2.0 or more, or 2.5 or more. The ratio of the thickness of the circuit connection adhesive film 10 to the average particle diameter of the conductive particles 3 may be 10.0 or less, 8.0 or less, 5.0 or less, or 3.0 or less, from the viewpoint of reducing resistance. It may be 0 or less. From these viewpoints, the ratio of the thickness of the circuit connecting adhesive film 10 to the average particle diameter of the conductive particles 3 may be 1.1 to 10.0, 1.5 to 8.0, 2.0. ~5.0, 2.5~5.0, or 1.5~3.0.

The particle density of the conductive particles 3 may be 5,000 particles/mm ² or more, 10,000 particles/mm ² or more, or 20,000 particles/mm ² or more from the viewpoint of easily obtaining stable connection resistance. The particle density of the conductive particles 3 may be 50,000 particles/mm ² or less, 40,000 particles/mm ² or less, or 30,000 particles/mm ^{2 or} less from the viewpoint of improving the insulation between adjacent electrodes. From these viewpoints, the particle density of the conductive particles 3 may be 5,000 to 50,000 particles/mm ² , 10,000 to 40,000 particles/mm ² or 20,000 to 30,000 particles/mm ² .

From the viewpoint of further improving conductivity, the content of the conductive particles 3 is, for example, 40% by mass or more, 50% by mass or more, or 60% by mass or more, based on the total mass of the circuit connection adhesive film 10. It may be. From the viewpoint of easily suppressing short circuits, the content of the conductive particles 3 may be, for example, 80% by mass or less, 75% by mass or less, or 70% by mass or less, based on the total mass of the circuit connection adhesive film 10. . From these viewpoints, the content of the conductive particles 3 may be, for example, 40 to 80% by mass, 50 to 75% by mass, or 60 to 70% by mass, based on the total mass of the circuit connection adhesive film 10. .

Although one embodiment of the circuit connection adhesive film has been described above, the circuit connection adhesive film is not limited to the above embodiment. For example, a plurality of conductive particles present in the circuit-connecting adhesive film may not be arranged in a predetermined pattern when the circuit-connecting adhesive film is viewed from above. Moreover, the adhesive film for circuit connection may further include an adhesive layer other than the first adhesive layer and the second adhesive layer.

<Method for manufacturing adhesive film for circuit connection>
A method for producing an adhesive film for circuit connection includes preparing a first adhesive film comprising a first adhesive layer and conductive particles partially embedded in one side of the first adhesive layer. and a step (II) of providing a second adhesive layer on one side of the first adhesive layer, the step (I) comprising a precursor comprising an externally stimulated curable composition. The method includes a curing step of curing the precursor layer by external stimulation to form a first adhesive layer in a state where the conductive particles are partially embedded in one side of the body layer.

Step (I) may further include a transfer step of transferring the conductive particles from the substrate to the precursor layer by providing the precursor layer on the surface of the substrate on which a plurality of conductive particles are arranged. . By performing the transfer step, it becomes easy to embed adjacent conductive particles in the precursor layer in a state where they are separated from each other.

Step (I) may further include, before the transfer step, a heating step of heating the layer containing the external stimulation curable composition at 50 to 70° C. for 3 to 60 minutes. By performing the heating process, the embedding rate of conductive particles in the precursor layer in the transfer process can be adjusted, and it is easy to obtain an adhesive film for circuit connection having a desired particle embedding rate. Become. If the precursor layer has sufficient hardness to obtain the desired particle embedding, the heating step may not be performed.

Step (I) may further include, after the transfer step, a pressurizing step of applying pressure to the surface of the precursor layer to which the conductive particles have been transferred. By performing the pressurizing step, the conductive particles can be further embedded in the precursor layer, and the particle embedding rate can be increased. If a sufficient particle embedding rate is obtained in the transfer process, the pressurizing process may not be performed.

Hereinafter, with reference to FIGS. 4 to 7, a method for manufacturing a circuit-connecting adhesive film will be described, taking as an example the method for manufacturing the circuit-connecting adhesive film 10 of the above embodiment. Note that the descriptions that overlap with those described for the circuit connection adhesive film 10 of the above embodiment, such as details of the first adhesive layer, conductive particles, second adhesive layer, external stimulus curable composition, etc. Omitted.

FIG. 4 is a schematic diagram showing the transfer step in step (I). FIG. 5 is a schematic diagram showing the pressurizing step in step (I). FIG. 6 is a schematic diagram showing the curing step in step (I). FIG. 7 is a schematic diagram showing step (II).

(Step (I))
[Substrate preparation]
In step (I), first, a film provided with a precursor layer containing an externally stimulated curable composition and a substrate on which a plurality of conductive particles are arranged are prepared.

For example, the laminated film 12 shown in FIG. 4(a) can be used as the film provided with the precursor layer containing the externally stimulated curable composition. The laminated film 12 includes a first support 21 and a precursor layer 11 provided on the first support 21.

The first support 21 may be a plastic film or a metal foil. Examples of the first support 21 include oriented polypropylene (OPP), polyethylene terephthalate (PET), polyethylene naphthalate, polyethylene isophthalate, polybutylene terephthalate, polyolefin, polyacetate, polycarbonate, polyphenylene sulfide, polyamide, polyimide, and cellulose. , ethylene/vinyl acetate copolymer, polyvinyl chloride, polyvinylidene chloride, synthetic rubber, liquid crystal polymer, or the like may be used as a base material (for example, a film).

The precursor layer 11 is formed by applying an external stimulus-curable composition or its solution (varnish) onto the first support 21, and optionally heating the obtained layer (layer containing the external stimulus-curable composition). It can be formed by drying. The varnish is prepared by mixing the components of the external stimuli-curable composition in an organic organic solvent. Coating can be performed using a knife coater, roll coater, applicator, comma coater, die coater, or the like. The heating conditions for volatilizing the organic solvent from the varnish applied to the base material can be set depending on the type of organic solvent used, but in this embodiment, the heating conditions From the viewpoint of adjusting the particle embedding rate, drying may be performed for a longer time than usual. The heating conditions may be, for example, 50 to 70°C for 3 to 60 minutes. However, the heating conditions can be adjusted depending on the desired melt viscosity of the precursor layer 11.

The minimum melt viscosity of the precursor layer 11 may be 30 to 10,000 Pa·s, or 50 to 5,000 Pa·s. The minimum melt viscosity of the precursor layer is determined, for example, by laminating a plurality of precursor layers to a thickness of 300 μm to 500 μm using a laminator (Leon 13DX (Lamy Corporation)), and then applying , can be determined by performing viscoelasticity measurement using ARES-G2 (TA instruments).The lamination conditions of the precursor layer are, for example, 50° C., paper passing speed of 1 m/min, and device setting S8. Viscoelasticity measurement is performed, for example, in the measurement temperature range of 0°C to 200°C.The lowest value of the measured melt viscosities (Pa・s) is taken as the minimum melt viscosity.The precursor layer is heated at 20°C. It is preferable to exhibit a complex viscosity of 1,000 to 10,000 Pa・s at a temperature in the range of ~80°C. Near 2,000 Pa・s (for example, 1,500 to 3,000 Pa・s) at a temperature in the range of 40°C to 70°C. More preferably, it exhibits a complex viscosity of .

The organic solvent used in preparing the varnish is not particularly limited as long as it has the property of substantially uniformly dissolving or dispersing the components of the external stimulation-curable composition. Examples of such organic solvents include toluene, acetone, methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate, propyl acetate, butyl acetate, and the like. These organic solvents can be used alone or in combination of two or more. Mixing during the preparation of the varnish can be carried out using, for example, a stirrer, a miller, a three-roll mill, a ball mill, a bead mill, a homodisper, or the like.

As the base, for example, the base 22 shown in FIG. 4(a) can be used. The base body 22 has a plurality of recesses on its surface in which conductive particles are arranged. The plurality of recesses are, for example, regularly arranged in a predetermined pattern (for example, a pattern corresponding to the electrode pattern of the circuit member). When the recesses are arranged in a predetermined pattern, the conductive particles 3 will be transferred to the first adhesive layer in a predetermined pattern. Therefore, a circuit-connecting adhesive film 10 in which conductive particles 3 are regularly arranged in a predetermined pattern (such as the pattern shown in FIG. 1) is obtained. The shape and size of the recessed portion of the base body 22 can be set from the viewpoints of the shape and size of the conductive particles, the embedding rate of the particles in the first adhesive layer, and the like. As the material constituting the base body 22, for example, inorganic materials such as silicon, various ceramics, glass, metals such as stainless steel, and organic materials such as various resins can be used. The method of arranging (accommodating) the conductive particles 3 in the recesses of the base body 22 is not particularly limited. For example, by placing the conductive particles 3 on the surface of the base 22 and rubbing the surface of the base 22 using a squeegee or a slightly adhesive roller, the conductive particles 3 are placed in the recesses while removing excess conductive particles 3. can do. Examples of methods for removing excess solder particles include blowing compressed air and rubbing the surface of the substrate 22 with a nonwoven fabric or a bundle of fibers. Further, the conductive particles 3 may be arranged in the recesses by forming the conductive particles 3 within the recesses of the base body 22 . Although not shown, instead of the base body 22, a base body having a support portion (such as a needle) on its surface that can fix the conductive particles can also be used.

[Transfer process]
Next, by providing the precursor layer 11 on the surface of the base 22 on which the conductive particles 3 are arranged, the conductive particles 3 are transferred from the base 22 to the precursor layer 11 (see FIG. 4). Specifically, first, the surface of the base 22 where the concave portion is formed (the surface of the base 22) and the surface of the laminated film 12 on the precursor layer 11 side (the first support 21 of the precursor layer 11 are The base body 22 and the precursor layer 11 are brought close to each other with the opposite surfaces facing each other (see FIG. 4(a)). Next, by bonding the laminated film 12 and the base 22 together, the precursor layer 11 is brought into contact with the surface of the base 22 (the surface on which the recesses are formed), and the conductive particles 3 are transferred to the precursor layer 11 ( (See Figure 4(b).) As a result, the first particle-coated laminated film 13 shown in FIG. 4(c) is obtained. The first particle-attached laminate film 13 includes a first support 21 , a precursor layer 11 , and conductive particles 3 partially embedded in the precursor layer 11 .

Examples of methods for bonding the laminated film 12 and the base 22 include hot pressing, roll lamination, vacuum lamination, and the like. Lamination can be performed, for example, at a temperature of 0 to 80°C. The temperature during transfer may be the lowest temperature at which the particle transfer rate to the precursor layer 11 is 98% or more.

Although not shown, in the transfer step, the precursor layer 11 may be formed by directly applying an externally stimulated curable composition or its solution (varnish) to the substrate 22.

[Pressure process]
Next, pressure is applied to the surface of the precursor layer 11 onto which the conductive particles 3 have been transferred. Specifically, for example, as shown in FIG. 5A, after the protective film 23 is attached to the surface of the precursor layer 11 to which the conductive particles 3 are transferred, the first support 21 side and the protective film 23 are attached. Pressure (P1 and P2 in FIG. 5(a)) is applied to the first particle-attached laminated film 13 from the film 23 side. As a result, the conductive particles 3 are further embedded in the precursor layer, and a second particle-attached laminated film 14 shown in FIG. 5(b) is obtained.

As the protective film 23, for example, a release film whose surface has been subjected to a release treatment can be used. Depending on the type of precursor layer 11, the protective film 23 may not be used.

Examples of methods for applying pressure include pressing, roll lamination, vacuum lamination, and the like. The pressure may be between 0.1 and 10 MPa. The pressurization time may be 0.5 to 20 seconds. In the pressurizing step, heating may be performed simultaneously with pressurizing. The temperature during pressurization may be, for example, 20 to 70°C.

[Curing process]
Next, an external stimulus is applied to the precursor layer 11 containing the external stimulus-curable composition to cure the precursor layer. For example, when the externally stimulated curable composition is a thermosetting and photocurable composition, the precursor layer 11 is irradiated with light (actinic rays) 24 as shown in FIG. This causes the precursor layer 11 to harden. As a result, the first adhesive film 15 shown in FIG. 6(b) is obtained. The first adhesive film 15 is attached to the first support 21, the first adhesive layer 1, and one side of the first adhesive layer 1 (the opposite side to the first support 21). and partially embedded conductive particles 3.

For light irradiation, irradiation light (for example, ultraviolet light) within a wavelength range of 150 to 750 nm may be used. Light irradiation can be performed using, for example, a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a xenon lamp, a metal halide lamp, an LED light source, or the like. The amount of light irradiation is not particularly limited, and the cumulative amount of light with a wavelength of 350 nm may be 100 mJ/cm ² or more, 200 mJ/cm ² or more, or 300 mJ/cm ² or more. The amount of light irradiation may be 10,000 mJ/cm ² or less, 5,000 mJ/cm 2 or less, or 3,000 mJ/cm ² ^or less as an integrated amount of light with a wavelength of 365 nm.

In FIG. 6, the second laminated film 14 with particles is used, but if the pressurizing process is not performed, the first laminated film 13 with particles can be used instead of the second laminated film 14 with particles. good. Further, in the curing step, heat treatment may be performed in place of or in addition to light irradiation.

(Step (II))
In step (II), first, a film provided with the second adhesive layer 2 is prepared. As the film including the second adhesive layer 2, a second adhesive film 16 shown in FIG. 7(a) can be used. The second adhesive film 16 includes a second support 25 and a second adhesive layer 2 provided on the second support 25.

As the second support 25, the base material exemplified as the first support 21 can be used. The second adhesive layer 2 can be formed in the same manner as the precursor layer 11, except that the second adhesive composition is used instead of the external stimulation curable composition.

Next, a second adhesive layer is applied to the first adhesive layer 1 side of the first adhesive film 15 prepared in step (I) (the side opposite to the support 21 of the first adhesive layer 1). The second adhesive film 16 is attached from the second side, and the second adhesive layer 2 is laminated on the first adhesive layer 1 (see FIG. 7). As a result, a support-attached circuit connection adhesive film 17 shown in FIG. 7(b) is obtained. The circuit connection adhesive film 17 with a support includes a first support 21 , a circuit connection adhesive film 10 , and a second support 25 .

Examples of methods for bonding the first adhesive film 15 and the second adhesive film 16 include methods such as hot pressing, roll lamination, and vacuum lamination. Lamination can be performed, for example, at a temperature of 0 to 80°C.

In step (II), the second adhesive composition or its solution (varnish) is applied to the first adhesive layer 1 in the same manner as in the method of forming the second adhesive layer on the second support 25. The second adhesive layer 2 may be provided on the first adhesive layer 1 by directly applying the second adhesive layer 2 to the first adhesive layer 1.

<Connected structure and its manufacturing method>
The connection structure includes a first circuit member having a first electrode, a second circuit member having a second electrode electrically connected to the first electrode, and a first circuit member having a first electrode and a second electrode. The device includes a connection portion that electrically connects the electrodes to each other via conductive particles and adheres the first circuit member and the second circuit member. The connection portion includes a cured product of a circuit connection adhesive film.

A method for manufacturing a connected structure includes a method for manufacturing a first circuit member having a first electrode on which the first electrode is provided, and a second circuit member having the second electrode on which the second electrode is provided. a laminate including a first circuit member, a circuit connection adhesive film, and a second circuit member; By heating the first electrode and the second electrode while being pressed in the direction, 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. and include.

Hereinafter, with reference to FIGS. 8 and 9, a connection structure (circuit connection structure) using the above-mentioned circuit connection adhesive film 10 as a connection material and a method for manufacturing the same will be exemplified. The manufacturing method will be explained.

FIG. 8 is a schematic cross-sectional view showing one embodiment of the connected structure. As shown in FIG. 8, the connection structure 100 includes a first circuit board 31 and a first circuit member 33 having a first electrode 32 formed on the main surface 31a of the first circuit board 31; A second circuit member 36 having a second circuit board 34 and a second electrode 35 formed on the main surface 34a of the second circuit board 34, and a first electrode 32 and a second electrode 35. It includes a connecting portion 40 that is electrically connected to each other via conductive particles 43 and that adheres the first circuit member 33 and the second circuit member 36.

The first circuit member 33 and the second circuit member 36 may be the same or different from each other. The first circuit member 33 and the second circuit member 36 may be a glass substrate or a plastic substrate on which circuit electrodes are formed; a printed wiring board; a ceramic wiring board; a flexible wiring board; an IC chip such as a driving IC; It's fine. The first circuit board 31 and the second circuit board 34 may be formed of a semiconductor, an inorganic material such as glass or ceramic, an organic material such as polyimide or polycarbonate, or a composite material such as glass/epoxy. The first circuit board 31 may be a plastic board. The first circuit member 33 may be, for example, a plastic substrate (a plastic substrate made of an organic material such as polyimide, polycarbonate, polyethylene terephthalate, or cycloolefin polymer) on which circuit electrodes are formed, and the second circuit member 33 may be a plastic substrate on which circuit electrodes are formed. The member 36 may be, for example, an IC chip such as a driving IC. In the plastic substrate on which the electrodes are formed, a display area is formed by, for example, pixel drive circuits such as organic TFTs or a plurality of organic EL elements R, G, B being regularly arranged in a matrix on the plastic substrate. It may be something like that.

The first electrode 32 and the second electrode 35 are made of metals such as gold, silver, tin, ruthenium, rhodium, palladium, osmium, iridium, platinum, copper, aluminum, molybdenum, titanium, etc., indium tin oxide (ITO), The electrode may include an oxide such as indium zinc oxide (IZO) or indium gallium zinc oxide (IGZO). The first electrode 32 and the second electrode 35 may be electrodes formed by laminating two or more of these metals, oxides, etc. The electrode formed by laminating two or more types may have two or more layers, or may have three or more layers. The first electrode 32 and the second electrode 35 may be circuit electrodes or bump electrodes. In FIG. 8, the first electrode 32 is a circuit electrode, and the second electrode 35 is a bump electrode.

The total value of the height of the first electrode 32 and the height of the second electrode 35 is smaller than the average particle diameter of the conductive particles 3 in the circuit connection adhesive film used to form the connection part 40. good. The total value may be, for example, 30 μm or less, 20 μm or less, 15 μm or less, 10 μm or less, 5 μm or less, less than 4 μm, less than 3 μm, less than 2 μm, or less than 1 μm. The height of the first electrode 32 (for example, the height of the circuit electrode) may be, for example, 0.05 to 5.0 μm, 0.1 to 4.0 μm, or 0.5 to 3.0 μm. The height of the second electrode 35 (for example, the height of the bump electrode) may be, for example, 0.5 to 25.0 μm, 2.0 to 15.0 μm, or 5.0 to 10.0 μm.

The connection portion 40 is a cured product of the circuit connection adhesive film 10. For example, the connecting portion 40 is located on the first circuit member 33 side in the direction in which the first circuit member 33 and the second circuit member 36 face each other, and includes a cured product of the first adhesive layer 1. The first region 41 is located on the second circuit member 36 side in the direction in which the first circuit member 33 and the second circuit member 36 face each other, and includes a cured product of the second adhesive layer 2. The conductive particles 43 that are interposed between the second region 42 and the first electrode 32 and the second electrode 35 and electrically connect the first electrode 32 and the second electrode 35 to each other are adjacent to each other. It has conductive particles 3 located between the electrodes. The connecting part 40 does not have to have two distinct areas between the first area 41 and the second area 42, for example, the first adhesive layer 1 and the second adhesive layer It may include a hardened region in which layer 2 is mixed.

Examples of the connection structure include a color display in which a plastic substrate on which minute LED elements (light emitting elements) are regularly arranged and a drive circuit element that is a driver for displaying an image is connected; An example of this is a micro LED display device such as a touch panel in which a regularly arranged plastic substrate and a position input element such as a touch pad are connected. The connected structure may be an organic EL display device in which the LED elements are organic EL elements. The connection structure can also be applied to various monitors such as smart phones, tablets, televisions, vehicle navigation systems, and wearable terminals; furniture; home appliances; daily necessities, and the like.

FIG. 9 is a schematic cross-sectional view showing an embodiment of a method for manufacturing the connected structure 100. FIGS. 9A and 9B are schematic cross-sectional views showing each step. As shown in FIG. 9, the method for manufacturing the connection structure 100 includes a surface where the first electrode 32 of the first circuit member 33 is provided, and a surface where the second electrode 35 of the second circuit member 36 is provided. A laminate including the first circuit member 33, the circuit connection adhesive film 10, and the second circuit member 36. is heated while being pressed in the thickness direction of the laminate, thereby electrically connecting the first electrode 32 and the second electrode 35 to each other via the conductive particles 43, and forming the first circuit. This includes adhering the member 33 and the second circuit member 36.

Specifically, first, the first circuit member 33 including the first circuit board 31 and the first electrode 32 formed on the main surface 31a of the first circuit board 31, and the second circuit board 34 and a second circuit member 36 including a second electrode 35 formed on the main surface 34a of the second circuit board 34.

Next, the first circuit member 33 and the second circuit member 36 are arranged so that the first electrode 32 and the second electrode 35 face each other, and the first circuit member 33 and the second circuit member The circuit connection adhesive film 10 is placed between the circuit connection member 36 and the circuit connection adhesive film 10 . For example, as shown in FIG. 9A, the circuit connecting adhesive film 10 is attached to the first circuit member with the first adhesive layer 1 side facing the main surface 31a of the first circuit board 31. Laminate on 33. Next, the circuit connection adhesive film 10 was laminated so that the first electrode 32 on the first circuit board 31 and the second electrode 35 on the second circuit board 34 faced each other. A second circuit member 36 is placed on the first circuit member 33.

Then, as shown in FIG. 9(b), a laminate in which the first circuit member 33, the circuit connection adhesive film 10, and the second circuit member 36 are laminated in this order is formed into the laminate. By heating while being pressed in the thickness direction of the body, the first circuit member 33 and the second circuit member 36 are thermocompression bonded to each other. At this time, as shown by arrows in FIG. 9(b), the flowable uncured thermosetting components contained in the first adhesive layer 1 and the second adhesive layer 2 are adjacent to each other. It flows so as to fill the gaps between the electrodes (the gaps between the first electrodes 32 and the gaps between the second electrodes 35), and is cured by the heating. As a result, the first electrode 32 and the second electrode 35 are electrically connected to each other via the conductive particles 43, and the first circuit member 33 and the second circuit member 36 are bonded to each other. A connected structure 100 shown in 8 is obtained.

The temperature and time during thermocompression bonding may be any temperature that can sufficiently cure the circuit connection adhesive film 10 and bond the first circuit member 33 and the second circuit member 36. The thermocompression bonding temperature may be 150 to 200°C. The thermocompression bonding time may be 4 to 7 seconds.

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

<Preparation of materials>
The materials shown below were prepared.

(A: cationic polymerizable compound)
・A1: Celoxide 8010 (bi-7-oxabicyclo[4.1.0]heptane, manufactured by Daicel Corporation, epoxy equivalent: about 100 g/eq)
・A2: ETERNACOLL OXBP (4,4'-bis[3-ethyl-3-oxetanyl]methoxymethyl]biphenyl, manufactured by Ube Industries, Ltd.)
・A3: jER1010 (bisphenol A type solid epoxy resin, manufactured by Mitsubishi Chemical Corporation, epoxy equivalent: 3000 to 5000 g/eq, number average molecular weight: 5500)
・A4: jER1007 (bisphenol A type solid epoxy resin, manufactured by Mitsubishi Chemical Corporation, epoxy equivalent: 1750 to 2200 g/eq)

(B: thermal cationic polymerization initiator)
・B1: YH-MS20 (ammonium salt-based thermal cationic polymerization initiator, manufactured by Yokohama Rubber Co., Ltd.)

(C: radically polymerizable compound)
・C1: NK ester A-BPEF (9,9-bi[4-(2-acryloyloxyethoxy)phenyl]fluorene, manufactured by Shin Nakamura Chemical Co., Ltd.)
・C2: Lipoxy VR-90 (bisphenol A type epoxy methacrylate, manufactured by Showa Denko K.K.)

(D: photoradical polymerization initiator)
・D1: Irgacure OXE-02 (1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-ethanone 1-(O-acetyloxime), manufactured by IGM Resins)

(E: thermoplastic resin)
・E1: YP-70 (bisphenol A/bisphenol F copolymerized phenoxy resin, manufactured by Nippon Steel Chemical & Materials Co., Ltd., weight average molecular weight: 50,000 to 60,000, Tg: 70 to 80°C)
・E2: Phenoxy resin P-1 synthesized below

(F: coupling agent)
・F1: SH-6040 (γ-glycidoxypropyltrimethoxysilane, manufactured by Dow Corning Toray Co., Ltd.)

(G: filler)
・G1: R805 (octylsilane surface treated silica fine particles, manufactured by Nippon Aerosil Co., Ltd., average particle diameter: 12 nm)

(H: thermosetting reaction rate regulator)
H1: ε-caprolactam (manufactured by Fujifilm Wako Pure Chemical Industries)

(I: conductive particles)
I1: Conductive particles in which a nickel layer with a thickness of 0.20 μm is formed on the surface of a core (particle) made of plastic (crosslinked polystyrene) (average particle size: 3.0 μm, C.V. value of particle size: 4.2%, specific gravity: 2.5)

<Synthesis of phenoxy resin P-1>
45 g of 4,4'-(9-fluorenylidene)-diphenol (manufactured by Sigma-Aldrich Japan Co., Ltd.) and 50 g of 3,3',5,5'-tetramethylbiphenol diglycidyl ether (YX-4000H, Mitsubishi Chemical Corporation) ) was dissolved in 1000 mL of N-methylpyrrolidone to prepare a reaction solution in a 3000 mL three-necked flask equipped with a Dimroth condenser, a calcium chloride tube, and a PTFE stirring bar connected to a stirring motor. 21 g of potassium carbonate was added to this, and the mixture was stirred while being heated to 110° C. with a mantle heater. After stirring for 3 hours, the reaction solution was dropped into a beaker containing 1000 mL of methanol, and the generated precipitate was collected by suction filtration. The filtered precipitate was further washed three times with 300 mL of methanol to obtain 75 g of phenoxy resin P-1 (Mn=15769, Mw=38045, Mw/Mn=2.413). The number average molecular weight Mn and the weight average molecular weight Mw of the phenoxy resin P-1 are polystyrene equivalent molecular weights measured under the following conditions using a high performance liquid chromatograph GP8020 manufactured by Tosoh Corporation.
[conditions]
・Column: Gelpak GL-A150S and GLA160S manufactured by Showa Denko Materials Co., Ltd.
・Eluent: Tetrahydrofuran ・Flow rate: 1.0ml/min

<Preparation of the base>
A substrate (PET film, thickness: 55 μm) having a plurality of recesses on its surface was prepared. The concave part of the base body has a truncated conical shape with the opening area expanding toward the surface side of the base body (when viewed from the top of the opening, the center of the bottom and the center of the opening are the same), the opening diameter is 4.3 μmφ, and the bottom diameter is 4.3 μmφ. was 4.0 μmφ, and the depth was 4.0 μm. The plurality of recesses on the base were regularly formed in a three-sided array with an interval of 6.2 μm (distance between the centers of each bottom) so that 29,000 recesses were formed per 1 mm square.

<Example 1>
(Step (I))
[Formation of precursor layer]
The materials shown in Table 1 were mixed to have the composition shown in Table 1 to prepare an external stimulation curable composition. The blending amounts in Table 1 indicate the solid content.

The obtained external stimulation curable composition was mixed with an organic solvent (2-butanone) to obtain a varnish. Next, this varnish was applied to a PET film with a thickness of 38 μm that had been treated with silicone mold release, and was dried with hot air at 60°C for 3 minutes using an explosion-proof dryer (DFB-80S, manufactured by Futaba Scientific Co., Ltd.) to remove the precursor. A body layer was formed on the PET film. Thereby, a laminated film including a PET film and a precursor layer was obtained.

[Transfer process]
Conductive particles (I1) are placed on the surface of the substrate prepared in advance on which the recesses are formed, and the excess conductive particles are removed by rubbing the surface of the substrate with the recesses with a slightly adhesive roller. Conductive particles were placed only within the recesses. Next, the substrate was placed on a heated hot plate (HP-2SA, manufactured by As One Co., Ltd.), and the surface of the substrate on which the concave portion was formed was opposed to the surface of the laminated film on the precursor layer side. The substrate and the laminated film were bonded together using a squeegee, and the conductive particles were transferred to the precursor layer. Thereby, a first particle-attached laminate film including a PET film, a precursor layer, and conductive particles partially embedded in the precursor layer was obtained. The heating temperature of the hot plate was set to the lowest temperature at which the particle transfer rate to the precursor layer was 98% or higher.

[Curing process]
Using a UV exposure machine (UVC-2534 1MNLC3-XJ01, manufactured by Ushio Inc.), the precursor layer is irradiated with ultraviolet rays from the side opposite to the PET film of the first laminated film with particles, and the light in the precursor layer is The curable components (radical polymerizable compound and radical photopolymerization initiator) were reacted and cured. Thereby, a first adhesive film comprising a PET film, a first adhesive layer, and conductive particles partially embedded in the first adhesive layer was obtained. Note that the exposure illuminance was 250±10 mW/cm ² , and the cumulative amount of light with a wavelength of 350 nm was 1500±50 mJ/cm ² . In addition, the exposure illuminance and integrated light amount were measured using an ultraviolet integrated light meter (UIT-250, manufactured by Ushio Inc.).

(Step (II))
[Preparation of second adhesive film]
A second adhesive composition was prepared by mixing the materials shown in Table 2 to have the composition shown in Table 2. The blending amounts in Table 2 indicate the solid content.

The obtained second adhesive composition was mixed with an organic solvent (2-butanone) to obtain a varnish. Next, this varnish was applied to a 38 μm thick PET film treated with silicone mold release, and dried with hot air at 60°C for 3 minutes using an explosion-proof dryer (DFB-80S, manufactured by Futaba Scientific Co., Ltd.). A second adhesive layer was formed on the PET film. Thereby, a second adhesive film including a PET film and a second adhesive layer was obtained.

[Lamination process]
The second adhesive film was pasted from the second adhesive layer side to the first adhesive layer side of the first adhesive film produced in step (I), and a hot roll laminator (Leon13DX, Inc.) was applied. (manufactured by Lamy Corporation) at a temperature of 50°C. Thereby, the adhesive film for circuit connection of Example 1 (the adhesive film for circuit connection with PET film) was obtained.

[Measurement of particle embedding rate]
First, a circuit connection adhesive film is sandwiched between two pieces of glass (thickness: approximately 1 mm), and 100 g of bisphenol A epoxy resin (product name: jER811, manufactured by Mitsubishi Chemical Corporation) and a curing agent (product name: Epomount) are added. A resin composition consisting of 10 g of a curing agent (manufactured by Refinetech Co., Ltd.) was cast. Next, the cross section was polished using a polishing machine to expose the longitudinal section (cross section in the thickness direction) of the circuit connection adhesive film. Next, a cross-sectional image (SEM image) was obtained by observation using a scanning electron microscope (SEM, trade name: SE-8020, manufactured by Hitachi High-Tech Science Co., Ltd.) at a magnification of 5,000 times. In an arbitrary 20 μm x 15 μm area in the obtained cross-sectional image, conductive particles have a maximum particle diameter L in the direction of embedding the conductive particles and a particle diameter L that is 0.85 to 1.00 times that of the conductive particles. The embedding ratio of conductive particles was determined, and the average value thereof was calculated. By performing the same operation on any 100 cross sections and further averaging the average value of the conductive particle embedding ratio calculated for each cross section, the conductive particle embedding ratio (particle embedding rate) was calculated. The results are shown in Table 3.

[Average particle diameter and particle diameter C. of conductive particles] V. Measurement of value]
Using the cross-sectional image acquired in the measurement of the particle embedding ratio, the average particle diameter and particle diameter C. V. The value was calculated. Specifically, in an arbitrary 20 μm x 15 μm area within the obtained cross-sectional image, the particle diameter L in the embedding direction of the conductive particles is measured, and the average value and C. V. The value was calculated. The same operation is performed for 100 arbitrary cross sections, and the average value of the average particle diameter of the conductive particles and the C. V. The average value of the values is determined, and these are calculated as the average particle diameter and C.I. of the particle diameter of the conductive particles in the circuit connection adhesive film. V. value. The average particle diameter of the conductive particles in the adhesive film for circuit connection is 2.3 μm, and the C.I. V. The value was 5.8%.

[Measurement of thickness]
Using the cross-sectional image obtained in the measurement of the particle embedding ratio above, the length from the boundary between the first adhesive layer and the second adhesive layer located in the separated part of adjacent conductive particles to the respective surfaces was measured, and the thickness of the first adhesive layer, the thickness of the second adhesive layer, and the thickness of the circuit-connecting adhesive film were determined. The thickness of the first adhesive layer in the circuit connection adhesive films of Examples 1 to 10 is 1.5 μm, the thickness of the second adhesive layer is 3.5 μm, and the circuit connection adhesive The thickness of the film was 5.0 μm.

[Measurement of flow rate]
First, a circuit connection adhesive film with a PET film was punched out in the thickness direction using a Biopsy Trappan BP-10F 1.0mm (manufactured by Kai Industries Co., Ltd.) to obtain a disc-shaped evaluation adhesive film with a diameter of 1mm. Obtained.

After peeling off the PET film on the first adhesive layer side from the obtained adhesive film for evaluation, the adhesive film for evaluation was attached to a cover glass manufactured by Matsunami Glass Industries (thickness: 0.05 mm) from the first adhesive layer side. 15 mm, width 18 mm, depth 18 mm), and using a thermocompression bonding device LD-06 manufactured by Ohashi Manufacturing Co., Ltd., apply the second adhesive under the conditions of a compression temperature of 70°C, a compression pressure of 0.1 MPa, and a compression time of 1.0 s. A temporary fixed body (cover glass/evaluation adhesive film/PET film) was obtained by thermocompression bonding from the layer side. Note that the compression temperature is the temperature reached when compression is performed for 1 second, and the compression pressure is the area-converted pressure of the adhesive film for evaluation.

Next, after peeling off the PET film on the second adhesive layer side from the temporary fixing body, a cover glass manufactured by Matsunami Glass Industries (thickness 0.15 mm, width 18 mm, depth 18 mm) was placed on the second adhesive layer. was placed thereon to obtain a laminate (cover glass/evaluation adhesive film/cover glass). Next, using a thermocompression bonding device FC3000WS manufactured by Toray Engineering Co., Ltd., the laminate was thermocompression bonded from the second adhesive layer side under conditions of a bonding temperature of 160° C., a bonding pressure of 2 MPa, and a bonding time of 5 seconds to obtain a bonded body. Note that the compression temperature is the maximum temperature reached by the evaluation adhesive film, and the compression pressure is the area-converted pressure of the evaluation adhesive film. To determine the maximum temperature, a dummy sample (the same laminate as the evaluation laminate) is prepared separately, and a thin temperature sensor (Rika ST-50D (manufactured by Kogyo Co., Ltd.) was sandwiched and thermocompression bonded, and the maximum temperature of the adhesive film in the dummy sample was adjusted by measuring in advance.

Observe the crimped body with an optical microscope (L300ND manufactured by Nikon Corporation), and use a length measurement tool to measure the adhesion area S _B1 (unit: mm ² ) between the surface of the crimped body on the first adhesive layer side and the cover glass. ) and the adhesion area S _B2 (unit: mm ² ) between the surface on the second adhesive layer side and the cover glass, and based on the following formulas (2-1a) and (2-2a), the first adhesive The flow rate of the adhesive layer and the flow rate of the second adhesive layer were calculated. Further, from the obtained flow rate, the ratio of the flow rate of the second adhesive layer 2 to the flow rate of the first adhesive layer 1 (flow ratio) was calculated. The results are shown in Table 3.
Flow rate of first adhesive layer [%]=S _B1 /(0.25π)×100...(2-1a)
Flow rate of second adhesive layer [%]=S _B2 /(0.25π)×100...(2-2a)

<Example 2>
An adhesive film for circuit connection was prepared in the same manner as in Example 1, except that the amount of the second adhesive composition used and the coating method were changed so that the thickness of the second adhesive layer was 15 μm. I got it. Further, the flow rate and the like were measured in the same manner as in Example 1. The results are shown in Table 3. In addition, the average particle diameter and C.I. of the particle diameter of the conductive particles in the circuit connection adhesive film. V. It was confirmed that the values were the same as in Example 1.

<Example 3>
A circuit connection adhesive film was obtained in the same manner as in Example 1, except that a pressure step was performed after the transfer step and before the curing step. In the pressurizing step, a release film (A3171 manufactured by Toyobo Co., Ltd., thickness: 50 μm) whose surface has been subjected to release treatment is placed on both sides of the first particle-coated laminate film, and then the obtained laminate is This was done by sandwiching the film while applying a temperature of 35° C. using a hot roll laminator (Leon 13DX, manufactured by Lamy Corporation). Further, the flow rate and the like were measured in the same manner as in Example 1. The results are shown in Table 3. In addition, the average particle diameter and C.I. of the particle diameter of the conductive particles in the circuit connection adhesive film. V. It was confirmed that the values were the same as in Example 1.

<Examples 4, 6 to 8>
An adhesive film for circuit connection was obtained in the same manner as in Example 1, except that the drying time when forming the precursor layer was changed as shown in Table 3. Further, the flow rate and the like were measured in the same manner as in Example 1. The results are shown in Table 3. In addition, the average particle diameter and C.I. of the particle diameter of the conductive particles in the circuit connection adhesive film. V. It was confirmed that the values were the same as in Example 1.

<Example 5, 9>
An adhesive film for circuit connection was obtained in the same manner as in Example 3, except that the drying time when forming the precursor layer was changed as shown in Table 3. Further, the flow rate and the like were measured in the same manner as in Example 1. The results are shown in Table 3. In addition, the average particle diameter and C.I. of the particle diameter of the conductive particles in the circuit connection adhesive film. V. It was confirmed that the values were the same as in Example 1.

<Example 10>
Circuit connection was carried out in the same manner as in Example 3, except that the drying time when forming the precursor layer was changed as shown in Table 3, and the heating temperature in the pressurization step was changed to 50°C. An adhesive film for use was obtained. Further, the flow rate and the like were measured in the same manner as in Example 1. The results are shown in Table 3. In addition, the average particle diameter and C.I. of the particle diameter of the conductive particles in the circuit connection adhesive film. V. It was confirmed that the values were the same as in Example 1.

<Comparative example 1>
In the same manner as in Example 1, a laminated film including a PET film and a precursor layer, and a second adhesive film including a PET film and a second adhesive layer were prepared. Next, a transfer step was performed in the same manner as in Example 1 except that a second adhesive film was used instead of the laminated film, and the conductive particles were transferred to the second adhesive layer. Next, a lamination step was carried out in the same manner as in Example 1, and a precursor layer was laminated on the second adhesive layer to which the conductive particles were transferred. Next, in the same manner as in Example 1, a curing step was performed to cure the precursor layer and form a first adhesive layer. Thereby, an adhesive film for circuit connection was obtained. In addition, the flow rate and the like were measured in the same manner as in Example 1. The results are shown in Table 3.

<Comparative example 2>
A circuit-connecting adhesive film was obtained in the same manner as in Comparative Example 1, except that a pressure step was performed after the transfer step and before the lamination step. The pressurization step was performed in the same manner as in Example 3. Further, the flow rate and the like were measured in the same manner as in Example 1. The results are shown in Table 3.

<Evaluation>
(Preparation of circuit connection structure)
Using each of the circuit connection adhesive films obtained above, a connected structure was produced by the following method.

First, a circuit board was prepared in which ITO circuit electrodes (pattern width 20 μm, inter-electrode space 10 μm) were formed on the surface of a glass substrate (#1737 manufactured by Corning, 38 mm×28 mm, thickness 0.5 mm). Next, the adhesive film for circuit connection is cut out into a square shape of 2.0 mm x 2.0 mm, and after peeling off the PET film on the first adhesive layer side of the adhesive film for circuit connection, the adhesive film for circuit connection is cut out. The circuit-connecting adhesive film was temporarily pressed onto the circuit board so that the first adhesive layer was in contact with the surface of the circuit board on which the circuit electrodes were formed, to obtain a temporarily pressed body. Temporary pressure bonding was performed by heating and pressurizing the circuit connection adhesive film for 1 second under the conditions of a measured maximum temperature of 70° C. and a pressure of 1 MPa in terms of adhesive film area. After the temporary pressure bonding, the PET film on the second adhesive layer side was pinched with tweezers and peeled off from the second adhesive layer. Next, an IC chip with bump electrodes arranged (outer diameter 0.5 mm x 0.5 mm, thickness 0.4 mm, bump electrode area 400 μm ² (length 20 μm x width 20 μm), space between bump electrodes 10 μm, bump electrode height 2 μm ), and after aligning the bump electrodes of the IC chip and the circuit electrodes of the glass substrate, the conditions of the measured maximum temperature of the circuit connection adhesive film of 160°C and the area-converted pressure of the bump electrodes of 125 MPa were applied. The second adhesive layer was attached to the IC chip by heating and pressing for 5 seconds. Thereby, a circuit connection structure was obtained.

(Evaluation of circuit connection structure)
The connection resistance and particle trapping properties of each circuit connection structure obtained above were evaluated by the following method. The results are shown in Table 3.

[Connection resistance evaluation]
The resistance value between the opposing electrodes of the circuit connection structure (between the bump electrode and the circuit electrode) was measured using a four-terminal measurement method using a multimeter (MLR21, manufactured by Kusumoto Kasei Co., Ltd.), and the resistance value was measured at 14 locations. The connection resistance was evaluated by comparing the average value of the measured values (initial mounting resistance value).

[Particle capture performance evaluation]
The appearance (mounted appearance) of the above-mentioned temporary press-bonded body and circuit connection structure was observed using a differential interference microscope from the glass substrate side, and the ability to capture conductive particles was evaluated. Specifically, first, at any five locations on the temporarily crimped body, we observe the area that will come into contact with a 100 μm x 100 μm square area containing nine bump electrodes of the IC chip, and check the conductivity contained within the area. The number of particles was counted, and the average value v _A1 of the obtained number of conductive particles at five locations was determined. Next, regarding the circuit connection structure obtained from the observed temporarily crimped body, the number of conductive particles contained in the same area at the same location (5 locations) as the observed location of the temporarily crimped body was counted, and the obtained conductive The average value _vA2 of the number of particles at five locations was determined. Next, from the average value v _A1 of the number of conductive particles determined for the temporary crimp body and the average value v _A2 of the number of conductive particles determined for the circuit connection structure, the particle residual rate x (v _A2 /v _A1 ×100) was calculated. Based on the obtained particle residual rate x, the trapping performance of the conductive particles was evaluated according to the following criteria.
5: x≧98%
4:90%≦x<98%
3:75%≦x<90%
2:50%≦x<75%
1:x<50%

In Table 3, the particle transfer layer refers to a layer to which conductive particles are transferred in the transfer step, and the drying time refers to the drying time during formation of the transfer layer.

DESCRIPTION OF SYMBOLS 1...First adhesive layer, 2...Second adhesive layer, 3...Conductive particles, 10...Adhesive film for circuit connection, 10...Adhesive film for circuit connection, 11...Precursor layer, 15...th 1 adhesive film, 16... second adhesive film, 22... base, 31... first circuit board, 32... first electrode (circuit electrode), 33... first circuit member, 34... second circuit board, 35... second electrode (bump electrode), 36... second circuit member, 40... connection part, 100... connection structure.

Claims

An adhesive film for circuit connection,
a first adhesive layer having thermosetting properties;
conductive particles partially embedded in one side of the first adhesive layer;
a second adhesive layer that has thermosetting properties and is in contact with the one surface of the first adhesive layer,
The embedding rate of the conductive particles in the first adhesive layer determined by the following formula (1) is 30 to 90%,
The circuit connection adhesive film was placed on the glass plate from the first adhesive layer side, and temporary pressure bonding was performed under the conditions of a pressure bonding temperature of 70° C., a bonding pressure of 0.1 MPa, and a bonding time of 1.0 s. The flow rate of each adhesive layer is defined by the following formula (2) when a glass plate is placed on the second adhesive layer and main pressure bonding is performed under the conditions of a pressure bonding temperature of 160°C, a pressure bonding pressure of 2 MPa, and a bonding time of 5 seconds. Then, the adhesive film for circuit connection has a ratio of the flow rate of the second adhesive layer to the flow rate of the first adhesive layer from 1.20 to 4.00.
Embedding rate (%) = H/L x 100...(1)
[In formula (1), H represents the length (unit: μm) of the conductive particles embedded in the first adhesive layer, and L represents the particle diameter (unit: μm) of the conductive particles in the embedding direction. ) is shown. ]
Flow rate [%] = S B / S A × 100... (2)
[In formula (2), S A represents the surface area of the adhesive layer before temporary pressure bonding, and S B represents the area of the adhesive layer after main pressure bonding. ]
The adhesive film for circuit connection according to claim 1, wherein the first adhesive layer has a flow rate of 88 to 110%.
The adhesive film for circuit connection according to claim 1 or 2, wherein the first adhesive layer is a cured product of a precursor layer containing an externally stimulated curable composition.
The adhesive film for circuit connection according to claim 3, wherein the externally stimulated curable composition has photocurability.
The adhesive film for circuit connection according to claim 1 or 2, wherein at least some of the plurality of conductive particles are arranged in a predetermined pattern in plan view.
The average particle diameter of the conductive particles is 1.0 to 50.0 μm,
C. of the particle diameter of the conductive particles. V. The adhesive film for circuit connection according to claim 1 or 2, having a value of 25% or less.
The adhesive film for circuit connection according to claim 1 or 2, wherein the ratio of the thickness of the adhesive film for circuit connection to the average particle diameter of the conductive particles is 1.1 to 10.0.
The adhesive film for circuit connection according to claim 1 or 2, wherein the ratio of the thickness of the second adhesive layer to the thickness of the first adhesive layer is 0.3 to 20.0.
A method for producing a circuit connecting adhesive film according to claim 1, comprising:
Step (I) of preparing a first adhesive film comprising the first adhesive layer and the conductive particles partially embedded in one side of the first adhesive layer;
a step (II) of providing the second adhesive layer on the one surface of the first adhesive layer,
In step (I), in a state where the conductive particles are partially embedded in one side of a precursor layer containing an external stimulus-curable composition, the precursor layer is cured by an external stimulus, and the first A method for producing an adhesive film for circuit connection, comprising a curing step of forming an adhesive layer.
The method for producing a circuit connection adhesive film according to claim 9, wherein in the curing step, the precursor layer is cured so that the flow rate of the first adhesive layer is 88 to 110%.
The external stimulation curable composition has photocurability,
The method for producing a circuit connection adhesive film according to claim 9 or 10, wherein in the curing step, the precursor layer is cured by light irradiation.
The step (I) further includes a transfer step of transferring the conductive particles from the substrate to the precursor layer by providing the precursor layer on the surface of the substrate on which a plurality of conductive particles are arranged. The method for producing a circuit connection adhesive film according to claim 9 or 10, comprising:
13. The circuit connection method according to claim 12, wherein the step (I) further includes a heating step of heating the layer containing the externally stimulated curable composition at 50 to 70° C. for 3 to 60 minutes before the transfer step. Method of manufacturing adhesive film.
The adhesive film for circuit connection according to claim 12, wherein the step (I) further includes, after the transfer step, a pressurizing step of applying pressure to the surface of the precursor layer to which the conductive particles have been transferred. Production method.
a first circuit member having a first electrode; a second circuit member having a second electrode electrically connected to the first electrode; and a first circuit member having a first electrode and a second electrode. and a connecting portion that electrically connects the circuit members to each other via conductive particles and adheres the first circuit member and the second circuit member,
A connection structure in which the connection portion includes a cured product of the circuit connection adhesive film according to claim 1 or 2.
A surface of a first circuit member having a first electrode on which the first electrode is provided and a surface of a second circuit member having a second electrode on which the second electrode is provided. Arranging the circuit connection adhesive film according to claim 1 or 2 between them;
By heating a laminate including the first circuit member, the circuit connection adhesive film, and the second circuit member while pressing the laminate in the thickness direction, the first electrode and A method for manufacturing a connected structure, the method comprising electrically connecting the second electrode to each other via conductive particles, and bonding the first circuit member and the second circuit member. .