CN116685652A - Adhesive film for circuit connection, method for producing same, connection structure, and method for producing same - Google Patents

Adhesive film for circuit connection, method for producing same, connection structure, and method for producing same Download PDF

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Publication number
CN116685652A
CN116685652A CN202180089778.2A CN202180089778A CN116685652A CN 116685652 A CN116685652 A CN 116685652A CN 202180089778 A CN202180089778 A CN 202180089778A CN 116685652 A CN116685652 A CN 116685652A
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China
Prior art keywords
component
conductive particles
adhesive film
circuit
mass
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CN202180089778.2A
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Chinese (zh)
Inventor
森谷敏光
赤井邦彦
市村刚幸
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Lishennoco Co ltd
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Lishennoco Co ltd
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    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J9/00—Adhesives characterised by their physical nature or the effects produced, e.g. glue sticks
    • C09J9/02—Electrically-conducting adhesives
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F2/00—Processes of polymerisation
    • C08F2/46—Polymerisation initiated by wave energy or particle radiation
    • C08F2/48—Polymerisation initiated by wave energy or particle radiation by ultraviolet or visible light
    • C08F2/50—Polymerisation initiated by wave energy or particle radiation by ultraviolet or visible light with sensitising agents
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F22/00—Homopolymers and copolymers of compounds having one or more unsaturated aliphatic radicals each having only one carbon-to-carbon double bond, and at least one being terminated by a carboxyl radical and containing at least one other carboxyl radical in the molecule; Salts, anhydrides, esters, amides, imides or nitriles thereof
    • C08F22/10—Esters
    • C08F22/1006—Esters of polyhydric alcohols or polyhydric phenols, e.g. ethylene glycol dimethacrylate
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G59/00—Polycondensates containing more than one epoxy group per molecule; Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups
    • C08G59/18—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing
    • C08G59/20—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing characterised by the epoxy compounds used
    • C08G59/22—Di-epoxy compounds
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G59/00—Polycondensates containing more than one epoxy group per molecule; Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups
    • C08G59/18—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing
    • C08G59/68—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing characterised by the catalysts used
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K3/00—Use of inorganic substances as compounding ingredients
    • C08K3/02—Elements
    • C08K3/08—Metals
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J11/00—Features of adhesives not provided for in group C09J9/00, e.g. additives
    • C09J11/02—Non-macromolecular additives
    • C09J11/04—Non-macromolecular additives inorganic
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J11/00—Features of adhesives not provided for in group C09J9/00, e.g. additives
    • C09J11/02—Non-macromolecular additives
    • C09J11/06—Non-macromolecular additives organic
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J201/00—Adhesives based on unspecified macromolecular compounds
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J4/00—Adhesives based on organic non-macromolecular compounds having at least one polymerisable carbon-to-carbon unsaturated bond ; adhesives, based on monomers of macromolecular compounds of groups C09J183/00 - C09J183/16
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J7/00—Adhesives in the form of films or foils
    • C09J7/30—Adhesives in the form of films or foils characterised by the adhesive composition
    • C09J7/35—Heat-activated
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B5/00—Non-insulated conductors or conductive bodies characterised by their form
    • H01B5/16—Non-insulated conductors or conductive bodies characterised by their form comprising conductive material in insulating or poorly conductive material, e.g. conductive rubber
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01R—ELECTRICALLY-CONDUCTIVE CONNECTIONS; STRUCTURAL ASSOCIATIONS OF A PLURALITY OF MUTUALLY-INSULATED ELECTRICAL CONNECTING ELEMENTS; COUPLING DEVICES; CURRENT COLLECTORS
    • H01R11/00—Individual connecting elements providing two or more spaced connecting locations for conductive members which are, or may be, thereby interconnected, e.g. end pieces for wires or cables supported by the wire or cable and having means for facilitating electrical connection to some other wire, terminal, or conductive member, blocks of binding posts
    • H01R11/01—Individual connecting elements providing two or more spaced connecting locations for conductive members which are, or may be, thereby interconnected, e.g. end pieces for wires or cables supported by the wire or cable and having means for facilitating electrical connection to some other wire, terminal, or conductive member, blocks of binding posts characterised by the form or arrangement of the conductive interconnection between the connecting locations
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01R—ELECTRICALLY-CONDUCTIVE CONNECTIONS; STRUCTURAL ASSOCIATIONS OF A PLURALITY OF MUTUALLY-INSULATED ELECTRICAL CONNECTING ELEMENTS; COUPLING DEVICES; CURRENT COLLECTORS
    • H01R43/00—Apparatus or processes specially adapted for manufacturing, assembling, maintaining, or repairing of line connectors or current collectors or for joining electric conductors

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  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Health & Medical Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Medicinal Chemistry (AREA)
  • Polymers & Plastics (AREA)
  • Inorganic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Adhesives Or Adhesive Processes (AREA)
  • Electric Connection Of Electric Components To Printed Circuits (AREA)
  • Conductive Materials (AREA)

Abstract

A method for manufacturing an adhesive film for circuit connection, comprising the steps of: preparing a substrate having a plurality of recesses on a surface thereof and conductive particles disposed in at least a part of the plurality of recesses; transferring the conductive particles to the composition layer by providing the composition layer containing the photocurable component and the 1 st thermosetting component on the surface of the substrate; forming a 1 st adhesive layer containing a cured product of a plurality of conductive particles and a photocurable component and a 1 st thermosetting component by irradiating the composition layer with light; and disposing a 2 nd adhesive layer containing a 2 nd thermosetting component on one face of the 1 st adhesive layer.

Description

Adhesive film for circuit connection, method for producing same, connection structure, and method for producing same
Technical Field
The present invention relates to an adhesive film for circuit connection and a method for producing the same, and a connection structure and a method for producing the same.
Background
The method of mounting the liquid crystal driving IC on the Glass panel for liquid crystal display can be roughly classified into two types, COG (Chip-on-Glass) mounting and COF (Chip-on-Flex) mounting. In COG mounting, an IC for driving a liquid crystal is directly bonded to a glass panel using an adhesive (for example, an adhesive for circuit connection) containing conductive particles. On the other hand, in COF mounting, a liquid crystal driving IC is bonded to a flexible tape having metal wiring, and these are bonded to a glass panel using an adhesive (for example, an adhesive for circuit connection) containing conductive particles.
However, with the recent high definition of liquid crystal display, the pitch and area of metal bumps as circuit electrodes of an IC for driving liquid crystal are gradually narrowed. Therefore, the conductive particles in the adhesive may flow out between adjacent circuit electrodes to cause a short circuit. This tendency is remarkable particularly in COG mounting. If the conductive particles flow out between the adjacent circuit electrodes, the number of conductive particles trapped between the metal bump and the glass panel decreases, and there is a possibility that connection failure occurs in which the connection resistance between the opposing circuit electrodes increases.
As a method for solving these problems, a method of forming composite particles (insulating coated conductive particles) by attaching a plurality of insulating particles (sub particles) to the surface of conductive particles (master particles) has been proposed. For example, patent document 1 proposes a method of attaching spherical resin particles to the surfaces of conductive particles.
Technical literature of the prior art
Patent literature
Patent document 1: japanese patent No. 4773685
Disclosure of Invention
Technical problem to be solved by the invention
In order to solve the above problems without using the insulating coated conductive particles, the present inventors studied to manufacture an adhesive film for circuit connection by: after the conductive particles are arranged in advance in the concave portion of the substrate having the concave portion formed therein, an adhesive layer is provided on the surface of the substrate having the concave portion formed therein, and the conductive particles are transferred to the adhesive layer. According to this method, the conductive particles can be arranged in a state of being separated from each other in a predetermined region in the thin film. Therefore, for example, by manufacturing the circuit-connecting adhesive film using a substrate having a concave pattern corresponding to the pattern (circuit pattern) of the electrode to be connected, the position and the number of the conductive particles in the circuit-connecting adhesive film can be sufficiently controlled.
However, in the above method, in order to transfer the conductive particles to the adhesive layer, it is necessary to make the adhesive layer have appropriate fluidity. Therefore, in the adhesive film for circuit connection obtained by the above method, the resin constituting the adhesive layer flows at the time of connection, and the conductive particles also flow, whereby the conductive particles may be eliminated from between the opposing circuit electrodes. Further, it is also considered to suppress the flow of the conductive particles by curing the adhesive layer after transferring the conductive particles to the adhesive layer, but at this time, the resin existing between the electrode and the conductive particles at the time of connection is not easily removed and a problem of an increase in connection resistance easily occurs.
Accordingly, a main object of the present invention is to provide a method for producing an adhesive film for circuit connection, which can improve the capturing rate of conductive particles between opposing circuit electrodes while sufficiently controlling the positions and the number of conductive particles, and can sufficiently ensure conduction between the electrodes.
Means for solving the technical problems
An aspect of the present invention relates to a method for producing an adhesive film for circuit connection shown in the following [1] to [18 ].
[1] A method for manufacturing an adhesive film for circuit connection, comprising the steps of: preparing a substrate having a plurality of recesses on a surface thereof and conductive particles disposed in at least a part of the plurality of recesses; transferring the conductive particles to a composition layer containing a photocurable component and a 1 st thermosetting component by providing the composition layer on the surface of the substrate; forming a 1 st adhesive layer containing a plurality of the conductive particles, a cured product of the photocurable component, and the 1 st thermosetting component by irradiating the composition layer with light; and disposing a 2 nd adhesive layer containing a 2 nd thermosetting component on one face of the 1 st adhesive layer.
[2] The method for producing an adhesive film for circuit connection according to [1], wherein the photocurable component comprises a radical polymerizable compound and a radical photopolymerization initiator, and the 1 st thermosetting component comprises a cation polymerizable compound and a thermal cation polymerization initiator.
[3] The method for producing an adhesive film for circuit connection according to [2], wherein the 1 st thermosetting component contains a compound having a cyclic ether group as the cationically polymerizable compound.
[4] The method for producing an adhesive film for circuit connection according to [3], wherein the 1 st thermosetting component contains at least 1 kind selected from the group consisting of oxetane compounds and alicyclic epoxy compounds as the cationically polymerizable compound.
[5] The method for producing an adhesive film for circuit connection according to any one of [2] to [4], wherein the photocurable component contains a compound represented by the following formula (1) as the radical polymerizable compound.
[ in formula (1), R 1 Represents a hydrogen atom or a methyl group, and X represents an alkanediyl group having 1 to 3 carbon atoms.]
[6] The method for producing an adhesive film for circuit connection according to any one of [2] to [5], wherein the photocurable component comprises a compound represented by the following formula (I) as the photo radical polymerization initiator.
In the formula (I), R 2 、R 3 R is R 4 Each independently represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an organic group containing an aromatic hydrocarbon group.
[7] The method for producing an adhesive film for circuit connection according to any one of [2] to [6], wherein the 1 st thermosetting component contains a salt compound having a cation represented by the following formula (II) or the following formula (III) as the thermal cationic polymerization initiator.
In the formula (II), R 5 R is R 6 Each independently represents 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 7 Represents an alkyl group having 1 to 6 carbon atoms,
in the formula (III), R 8 R is R 9 Each independently represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an organic group containing a substituted or unsubstituted aromatic hydrocarbon group, R 10 R is R 11 Each independently represents an alkyl group having 1 to 6 carbon atoms.
[8] The method for producing an adhesive film for circuit connection according to any one of [1] to [7], wherein the conductive particles have an average particle diameter of 1 to 30 μm and a c.v. value of the particle diameter of 20% or less.
[9] The method for producing an adhesive film for circuit connection according to any one of [1] to [8], wherein the conductive particles are solder particles.
[10] The method for producing an adhesive film for circuit connection according to [9], wherein the solder particles contain at least one selected from the group consisting of tin, tin alloy, indium and indium alloy.
[11] The method for producing an adhesive film for circuit connection according to [10], wherein the solder particles contain at least one selected from the group consisting of an In-Bi alloy, an In-Sn-Ag alloy, an Sn-Au alloy, an Sn-Bi-Ag alloy, an Sn-Ag-Cu alloy, and an Sn-Cu alloy.
[12] The method for producing an adhesive film for circuit connection according to any one of [9] to [11], wherein a part of the surface of the solder particle has a planar portion.
[13] The method for producing an adhesive film for circuit connection according to [12], wherein a ratio (B/A) of a diameter B of the planar portion to a diameter A of the solder particle satisfies the following formula.
0.01＜B/A＜1.0。
[14] The method for producing an adhesive film for circuit connection according to any one of [1] to [13], wherein when a quadrangle circumscribed with a projection image of the conductive particles is produced from two pairs of parallel lines, the distance between the opposing sides is taken as X and Y, and when Y < X, X and Y satisfy the following formula.
0.8＜Y/X≤1.0。
[15] The method for producing an adhesive film for circuit connection according to any one of [1] to [14], wherein the plurality of concave portions are formed in a prescribed pattern.
In the manufacturing method of the above aspect, a composition containing a photocurable component and a thermosetting component is used, and after the conductive particles are transferred to a layer (composition layer) made of the composition, the composition is subjected to photocuring. Therefore, resin flow at the time of connection can be suppressed without impairing transferability. Therefore, according to the manufacturing method of the above aspect, it is possible to obtain the adhesive film for circuit connection capable of improving the capturing rate of the conductive particles between the opposing circuit electrodes while sufficiently controlling the positions and the number of the conductive particles in the adhesive film for circuit connection. In the manufacturing method according to the above aspect, conduction between the electrodes can be sufficiently ensured. This is presumed to be because: by using a combination of the photocurable component and the thermosetting component, the thermosetting component can be contained in the layer (1 st adhesive layer) after photocuring of the composition layer, and fluidity of the resin can be imparted to the layer after photocuring to such an extent that the conductive particles are not excluded at the time of connection, so that occurrence of defects such as an increase in connection resistance due to the resin existing between the electrode and the conductive particles being difficult to exclude at the time of connection can be suppressed.
Another aspect of the present invention relates to an adhesive film for circuit connection shown in the following [16 ].
[16] An adhesive film for circuit connection containing conductive particles, comprising: a 1 st adhesive layer containing a plurality of the conductive particles, a cured product of a photocurable component, and a 1 st thermosetting component; and a 2 nd adhesive layer provided on the 1 st adhesive layer and containing a 2 nd thermosetting component, wherein at least a part of the plurality of conductive particles are arranged in a predetermined pattern when the circuit connection adhesive film is viewed in plan, and are arranged laterally in a state in which adjacent conductive particles are separated from each other in a longitudinal section of the circuit connection adhesive film.
Another aspect of the present invention relates to a connecting structure shown in the following [17 ].
[17] A connection structure is provided with: a 1 st circuit part having a 1 st electrode; a 2 nd circuit part having a 2 nd electrode; and a connecting portion including the cured body of the adhesive film for circuit connection of [16], electrically connecting the 1 st electrode and the 2 nd electrode to each other via the conductive particles, and bonding the 1 st circuit member and the 2 nd circuit member.
Another aspect of the present invention relates to a method for producing a connection structure shown in [18] below.
[18] A method of manufacturing a connection structure, comprising the steps of: disposing the adhesive film for circuit connection of [16] between a surface of a 1 st circuit member having a 1 st electrode on which the 1 st electrode is disposed and a surface of a 2 nd circuit member having a 2 nd electrode on which the 2 nd electrode is disposed; and heating a laminate including the 1 st circuit member, the adhesive film for circuit connection, and the 2 nd circuit member in a state of being pressed in a thickness direction of the laminate, thereby electrically connecting the 1 st electrode and the 2 nd electrode to each other via the conductive particles and bonding the 1 st circuit member and the 2 nd circuit member.
Effects of the invention
According to the present invention, a method for producing an adhesive film for circuit connection capable of improving the capturing rate of conductive particles between opposing circuit electrodes while sufficiently controlling the positions and the number of conductive particles and sufficiently ensuring conduction between the electrodes can be provided.
Drawings
Fig. 1 is a schematic cross-sectional view showing an embodiment of an adhesive film for circuit connection.
Fig. 2 is a schematic plan view showing an example of arrangement of conductive particles in the adhesive film for circuit connection of fig. 1.
Fig. 3 is a schematic plan view showing an example of arrangement of conductive particles in the adhesive film for circuit connection of fig. 1.
Fig. 4 is a schematic cross-sectional view showing another embodiment of an adhesive film for circuit connection.
Fig. 5 is a schematic cross-sectional view of a substrate for manufacturing the adhesive film for circuit connection of fig. 1.
Fig. 6 is a diagram showing a modification of the cross-sectional shape of the recess of the base body of fig. 5.
Fig. 7 is a view showing a state in which conductive particles are disposed in the concave portion of the base body of fig. 5.
Fig. 8 is a schematic cross-sectional view showing a step of a method for producing an adhesive film for circuit connection according to an embodiment.
Fig. 9 is a schematic cross-sectional view showing a step of the method for producing the adhesive film for circuit connection of fig. 1.
Fig. 10 is a schematic cross-sectional view showing a step of the method for producing the adhesive film for circuit connection of fig. 1.
Fig. 11 is a schematic cross-sectional view showing an embodiment of the connection structure.
Fig. 12 is a schematic cross-sectional view showing an embodiment of a method for manufacturing a connection structure.
Detailed Description
Hereinafter, embodiments of the present invention will be described. However, the present invention is not limited to the following embodiments. In addition, as for the materials exemplified below, one kind may be used alone or two or more kinds may be used in combination unless otherwise specified. The content of each component in the composition means the total amount of a plurality of substances present in the composition, unless otherwise specified, in the case where the plurality of substances corresponding to each component are present in the composition. The numerical ranges shown in the "to" are ranges including the numerical values before and after the "to" as the minimum value and the maximum value, respectively. In the numerical ranges described in the present specification in stages, the upper limit value or the lower limit value of the numerical range in one stage may be replaced with the upper limit value or the lower limit value of the numerical range in another stage. In the numerical ranges described in the present specification, the upper limit value or the lower limit value of the numerical range may be replaced with the value shown in the embodiment. In the present specification, "(meth) acrylate" means at least one of an acrylate and a methacrylate corresponding thereto. The same applies to other similar expressions such as "(meth) acryl".
Adhesive film for circuit connection
Fig. 1 is a view schematically showing a longitudinal section of an adhesive film for circuit connection according to an embodiment. The adhesive film 10A for circuit connection shown in fig. 1 is a film-like adhesive (adhesive film) provided with: a 1 st adhesive layer 1 containing a plurality of conductive particles 4, a cured product containing a photocurable component, and a 1 st adhesive component 3 containing a thermosetting component; and a 2 nd adhesive layer 2 provided on the 1 st adhesive layer 1 and containing a 2 nd thermosetting component. In the present specification, the "longitudinal section" refers to a section (section in the thickness direction) substantially orthogonal to a main surface (for example, a main surface of the adhesive film for circuit connection 10A). The 1 st thermosetting component and the 2 nd thermosetting component refer to thermosetting components contained in the 1 st adhesive layer and the 2 nd adhesive layer, respectively.
At least a part of the plurality of conductive particles 4 are arranged in a lateral direction in a state in which adjacent conductive particles are separated from each other in a vertical section of the adhesive film for circuit connection 10A. In other words, the adhesive film for circuit connection 10A is constituted by the central region 10A in which the conductive particles 4 in a state separated from the adjacent conductive particles in the longitudinal section thereof are laterally formed in a row and the surface side regions 10b, 10c in which the conductive particles 4 are not present. The term "transverse direction" as used herein refers to a direction (left-right direction in fig. 1) substantially parallel to the main surface of the adhesive film for circuit connection. Adjacent conductive particles are arranged in a laterally separated state from each other, and can be confirmed by, for example, observing a longitudinal section of the adhesive film for circuit connection by a scanning electron microscope or the like. In fig. 1, a part of the conductive particles 4 is exposed from the surface of the 1 st adhesive layer 1 (for example, protrudes to the 2 nd adhesive layer 2 side), but the entire conductive particles 4 may be embedded in the 1 st adhesive layer 1 so that the conductive particles 4 are not exposed from the surface of the 1 st adhesive layer 1.
Fig. 2 and 3 are plan views schematically showing an example of arrangement of the conductive particles 4 in the adhesive film for circuit connection 10A. As shown in fig. 2 and 3, at least a part of the plurality of conductive particles 4 are arranged in a predetermined pattern when the adhesive film for circuit connection is viewed from above. In fig. 2, the conductive particles 4 are arranged at regular and substantially uniform intervals throughout the entire area of the circuit-connecting adhesive film 10A when the circuit-connecting adhesive film is viewed from above, but for example, as shown in fig. 3, the conductive particles 4 may be arranged so that the area 10d where the plurality of conductive particles 4 are regularly arranged and the area 10e where the conductive particles 4 are not present are regularly formed when the circuit-connecting adhesive film is viewed from above. The positions and the number of the conductive particles 4 can be set according to, for example, the shape, size, pattern, and the like of the electrodes to be connected. At least a part of the plurality of conductive particles are arranged in a predetermined pattern, and can be confirmed by, for example, observing the circuit-connecting adhesive film from above the main surface of the circuit-connecting adhesive film using an electron microscope or the like.
(1 st adhesive layer)
The 1 st adhesive layer 1 contains a cured product of conductive particles 4 (hereinafter, sometimes referred to as "(a) component"), a photocurable component (hereinafter, sometimes referred to as "(B) component") and a 1 st thermosetting component (hereinafter, sometimes referred to as "(C) component"). (B) The cured product of the component (B) may be a cured product obtained by completely curing the component (B), or may be a cured product obtained by partially curing the component (B). (C) The component is a component that can flow at the time of connection, and is, for example, an uncured curable component (for example, a resin component). The component other than the conductive particles 4 constituting the 1 st adhesive layer 1 is, for example, a component having no conductivity (for example, an insulating resin component).
[ (A) component: conductive particles ]
The component (a) is not particularly limited as long as it is a particle having conductivity, and may be a metal particle composed of a metal such as Au, ag, pd, ni, cu or solder, a conductive carbon particle composed of conductive carbon, or the like. (A) The component (c) may be coated conductive particles including a core made of non-conductive glass, ceramic, plastic (polystyrene, etc.) or the like, and a coating layer made of the metal or conductive carbon and coating the core. (A) The component (a) can use 1 kind of conductive particles alone or 2 or more kinds of conductive particles in combination.
When the coated conductive particles are used as the component (a), the cured product of the thermosetting component is easily deformed by heating or pressing, so that the contact area between the electrode and the component (a) can be increased when the electrodes are electrically connected to each other, and the conductivity between the electrodes can be further improved.
In the case of using metal particles formed of a hot-melt metal as the component (a), the connection between the electrodes tends to be more firm. When solder particles are used as the component (a), this tendency is remarkable.
From the viewpoint of both the connection strength and the low melting point, the solder particles may contain at least one selected from the group consisting of tin, tin alloy, indium, and indium alloy.
As the tin alloy, for example, in-Sn alloy, in-Sn-Ag alloy, sn-Au alloy, sn-Bi-Ag alloy, sn-Ag-Cu alloy, sn-Cu alloy, or the like can be used. Specific examples of these tin alloys include the following.
In-Sn (In 52 mass%, sn48 mass%, melting point 118 ℃ C.)
In-Sn-Ag (In 20 mass%, sn77.2 mass%, ag2.8 mass%, melting point 175 ℃ C.)
Sn-Bi (Sn 43 mass%, bi57 mass%, melting point 138 ℃ C.)
Sn-Bi-Ag (Sn 42 mass%, bi57 mass%, ag1 mass%, melting point 139 ℃ C.)
Sn-Ag-Cu (Sn96.5 mass%, ag3 mass%, cu0.5 mass%, melting point 217 ℃ C.)
Sn-Cu (Sn99.3 mass%, cu0.7 mass%, melting point 227 ℃ C.)
Sn-Au (Sn21.0 mass%, au79.0 mass%, melting point 278 ℃ C.)
As the indium alloy, for example, an in—bi alloy, an in—ag alloy, or the like can be used. Specific examples of these indium alloys include the following.
In-Bi (In66.3 mass%, bi33.7 mass%, melting point 72 ℃ C.)
In-Bi (In33.0 mass%, bi67.0 mass%, melting point 109 ℃ C.)
In-Ag (In97.0 mass%, ag3.0 mass%, melting point 145 ℃ C.)
In addition, the above-described indium alloy containing tin is classified as a tin alloy.
The solder particles may contain at least one selected from the group consisting of In-Bi alloy, in-Sn-Ag alloy, sn-Au alloy, sn-Bi-Ag alloy, sn-Ag-Cu alloy, and Sn-Cu alloy In terms of higher reliability at the time of high temperature and high humidity test and at the time of thermal shock test.
The tin alloy or indium alloy may be selected according to the use of the solder particles (temperature at the time of use), and the like. For example, when the solder particles are used for soldering at low temperature, if an in—sn alloy or an sn—bi alloy is used, soldering can be performed at a temperature of 150 ℃. In the case of using a material having a high melting point such as a Sn-Ag-Cu alloy or a Sn-Cu alloy, high reliability can be maintained even after being left at a high temperature.
The solder particles may include one or more selected from Ag, cu, ni, bi, zn, pd, pb, au, P and B. When the solder particles contain Ag or Cu, the melting point of the solder particles can be reduced to about 220 ℃ and the bonding strength with the electrode can be further improved, so that better conduction reliability can be easily obtained.
The Cu content of the solder particles is, for example, 0.05 to 10 mass%, and may be 0.1 to 5 mass% or 0.2 to 3 mass%. When the Cu content is 0.05 mass% or more, better solder connection reliability is easily achieved. When the Cu content is 10 mass% or less, the melting point is low, and the solder particles are easily formed with excellent wettability, and as a result, the connection reliability of the joint portion by the solder particles is easily improved.
The Ag content of the solder particles is, for example, 0.05 to 10% by mass, and may be 0.1 to 5% by mass or 0.2 to 3% by mass. When the Ag content is 0.05 mass% or more, better solder connection reliability is easily achieved. When the Ag content is 10 mass% or less, the melting point is low, and the solder particles are easily formed with excellent wettability, and as a result, the connection reliability of the joint portion by the solder particles is easily improved.
The solder particles may have a planar portion at a portion of the surface thereof. In the case of using such solder particles, the planar portion of the solder particles contacts the electrode, and thus a large contact area can be ensured between the planar portion and the electrode. When an electrode made of a material which is easily spread by wetting with solder and an electrode made of a material which is not easily spread by wetting with solder are connected, the connection between the two electrodes can be appropriately performed by adjusting the planar portion of the solder particles to be disposed on the electrode side of the latter. The surface of the solder particle other than the plane portion may have a spherical cap shape. That is, the solder particles may be curved surfaces having a planar surface portion and a spherical cap shape. Specifically, the solder particles may have a shape in which a plane portion having a diameter B is formed on a part of the surface of the ball having a diameter a. When such solder particles are used, more excellent conduction reliability and insulation reliability are easily obtained.
In the case where the solder particles have a shape in which a flat portion having a diameter B is formed on a part of the surface of the ball having a diameter a, the ratio (B/a) of the diameter B of the flat portion to the diameter a of the solder particles may be, for example, more than 0.01 and less than 1.0 (0.01 < B/a < 1.0), or may be 0.1 to 0.9 from the viewpoint of achieving more excellent conduction reliability and insulation reliability. The diameter a of the solder particles and the diameter B of the flat surface portion can be observed by, for example, a scanning electron microscope. Specifically, arbitrary solder particles are observed by a scanning electron microscope, and an image is taken. The diameter A of the solder particles and the diameter B of the flat surface portion were measured from the obtained image, and the B/A of the particles was obtained. This operation was performed on 300 solder particles and an average value was calculated as the B/a of the solder particles.
When a quadrangle circumscribed with the projected image of the conductive particles is formed by two pairs of parallel lines, if the distance between the opposing sides is X and Y (where Y < X), respectively, the ratio of Y to X (Y/X) may be more than 0.8 and 1.0 or less (0.8 < Y/X. Ltoreq.1.0). Such conductive particles can be referred to as particles that are closer to spheres. If the conductive particles have a shape close to a sphere, the solder particles tend to be easily accommodated in the concave portion of the base in a manufacturing method described later. In addition, when the solder particles are used as the conductive particles, the solder particles have a shape close to a sphere, and thus, when the electrodes are electrically connected to each other via solder, unevenness is less likely to occur in contact between the solder particles and the electrodes, and stable connection tends to be obtained. The ratio of Y to X (Y/X) may be more than 0.8 and less than 1.0 (0.8 < Y/X < 1.0), or may be 0.81 to 0.99. The projection image of the conductive particles can be obtained by observing any conductive particles by a scanning electron microscope, for example. When Y/X is obtained, two pairs of parallel lines are drawn on the obtained projection image, one pair of parallel lines is arranged at a position where the distance between the parallel lines is the smallest, and the other pair of parallel lines is arranged at a position where the distance between the parallel lines is the largest. This operation was performed on 300 conductive particles and an average value of Y/X was calculated as Y/X of the conductive particles.
(A) The component (c) may be an insulating coated conductive particle comprising the metal particle, a conductive carbon particle, or an insulating layer containing an insulating material such as a resin and coating the surface of the particle. If the component (a) is an insulating coated conductive particle, even when the content of the component (a) is large, the insulating layer is provided on the surface of the particle, so that occurrence of short-circuiting due to contact between the components (a) can be suppressed, and the insulation between adjacent electrode circuits can be improved.
The average particle diameter of the component (A) may be 1 μm or more, 2 μm or more, or 4 μm or more from the viewpoint of easy obtaining of excellent electrical conductivity. The average particle diameter of the component (A) may be 30 μm or less, 25 μm or less, or 20 μm or less, from the viewpoint of easy obtaining of better connection reliability with the electrode of a minute size. From these viewpoints, the average particle diameter of the component (A) may be 1 to 30. Mu.m, 2 to 25. Mu.m, or 4 to 20. Mu.m.
(A) The average particle diameter of the components can be measured using various methods corresponding to the size. For example, methods such as dynamic light scattering, laser diffraction, centrifugal sedimentation, electrical detection zone, and resonance type mass measurement can be used. Further, a method of measuring the particle size from an image obtained by an optical microscope, an electron microscope, or the like can be utilized. Specific examples of the apparatus include a flow-type particle image analyzer, microtrac, and coulter counter. The particle diameter of the non-spherical component (a) may be the diameter of a circle circumscribed with the conductive particles in the SEM image.
The c.v. value of the particle diameter of the component (a) may be 20% or less, 10% or less, 7% or less, or 5% or less from the viewpoint of enabling more excellent conductive reliability and insulation reliability. (A) The lower limit of the c.v. value of the particle diameter of the component is not particularly limited, and may be, for example, 0.1% or more, 1% or more, or 2% or more.
The c.v. value of the particle diameter of the component (a) is calculated by multiplying a value obtained by dividing the standard deviation of the particle diameter of the conductive particles by the average particle diameter by 100. The standard deviation of the particle diameter of the conductive particles is measured by the same method as the measurement method of the average particle diameter of the conductive particles described above.
(A) The component (c) may be conductive particles having an average particle diameter of 1 to 30 μm and a c.v. value of 20% or less. Such conductive particles have both a small average particle diameter and a narrow particle size distribution, and can be suitably used as conductive particles for anisotropic conductive materials having high conductive reliability and insulating reliability.
The content of the component (a) may be, for example, 1 mass% or more, 5 mass% or more, or 10 mass% or more based on the total mass of the 1 st adhesive layer, in terms of further improving the conductivity. The content of the component (a) may be, for example, 80 mass% or less, 70 mass% or less, or 60 mass% or less based on the total mass of the 1 st adhesive layer, from the viewpoint of easy short circuit suppression. From these viewpoints, the content of the component (a) may be, for example, 1 to 80 mass%, 5 to 70 mass%, or 10 to 60 mass% based on the total mass of the 1 st adhesive layer.
The particle density of the component (A) in the 1 st adhesive layer 1 may be 100 pieces/mm from the viewpoint of obtaining stable connection resistance 2 Above 1000 pieces/mm 2 Above 3000 pieces/mm 2 Above or 5000 pieces/mm 2 The above. The particle density of the component (A) in the 1 st adhesive layer 1 may be 100000 pieces/mm from the viewpoint of improving the insulation between adjacent electrodes 2 Below 70000 pieces/mm 2 Below 50000 pieces/mm 2 Below or 30000 pieces/mm 2 The following is given.
[ (B) component: photocurable component ]
The component (B) is not particularly limited as long as it is a component (for example, a resin component) that is cured by light irradiation, but may be a component having radical curability from the viewpoint of further excellent connection resistance. (B) The component (c) may include, for example, a radical polymerizable compound (hereinafter, sometimes referred to as a "(B1) component") and a photo radical polymerization initiator (hereinafter, sometimes referred to as a "(B2) component"). (B) The component (B1) may be a component composed of a component (B2).
(B1) The components are as follows: radical polymerizable compound
(B1) The component (c) is a compound (radical polymerizable compound) having a polymerizable group (radical polymerizable group) that reacts by a radical. Examples of the radical polymerizable group include a (meth) acryloyl group, a vinyl group, an allyl group, a styryl group, an alkenyl group, an alkenylene group, and a maleimide group. The number of radical polymerizable groups (the number of functional groups) in the component (B1) may be 2 or more from the viewpoint of easily obtaining a desired melt viscosity after polymerization, further improving the effect of reducing the connection resistance, and further improving the connection reliability, and may be 10 or less from the viewpoint of suppressing the curing shrinkage at the time of polymerization. In order to maintain the balance between the crosslinking density and the curing shrinkage, a compound having a radical polymerizable group amount outside the above range may be used in addition to a compound having a radical polymerizable group amount within the above range.
In view of suppressing the flow of the conductive particles, for example, the (B1) component may contain a polyfunctional (2 or more functional) (meth) acrylate. The multifunctional (2-functional or more) (meth) acrylate may be a 2-functional (meth) acrylate, and the 2-functional (meth) acrylate may be a 2-functional aromatic (meth) acrylate.
Examples of the polyfunctional (meth) acrylate include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, polyethylene glycol di (meth) 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, quaternium glycol di (meth) acrylate, 3-methyl-1, 5-pentanediol di (meth) acrylate, 1, 6-hexanediol di (meth) acrylate, 2-butyl-2-ethyl-1, 3-propanediol di (meth) acrylate, 1, 9-nonanediol di (meth) acrylate, 1, 10-decanediol di (meth) acrylate, glycerol di (meth) acrylate, tricyclodecanedimethanol (meth) acrylate, ethoxylated 1, 3-propanediol di (meth) acrylate, trimethylolpropane and trimethylolpropane (meth) acrylate Aliphatic (meth) acrylates such as ethoxylated trimethylolpropane tri (meth) acrylate, propoxylated trimethylolpropane tri (meth) acrylate, ethoxylated propoxylated trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, ethoxylated pentaerythritol tri (meth) acrylate, propoxylated pentaerythritol tri (meth) acrylate, ethoxylated propoxylated pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, ethoxylated pentaerythritol tetra (meth) acrylate, propoxylated pentaerythritol tetra (meth) acrylate, ethoxylated propoxylated pentaerythritol tetra (meth) acrylate, ditrimethylolpropane tetra acrylate, dipentaerythritol hexa (meth) acrylate; an aromatic (meth) acrylate such as ethoxylated bisphenol a-type di (meth) acrylate, propoxylated bisphenol a-type di (meth) acrylate, ethoxylated bisphenol F-type di (meth) acrylate, propoxylated bisphenol F-type di (meth) acrylate, ethoxylated fluorene-type di (meth) acrylate (e.g., 9-bis [4- (2-acryloyloxyethoxy) phenyl ] fluorene), propoxylated fluorene-type di (meth) acrylate, ethoxylated propoxylated fluorene-type di (meth) acrylate; aromatic epoxy (meth) acrylates such as bisphenol type epoxy (meth) acrylate, novolac type epoxy (meth) acrylate, cresol novolac type epoxy (meth) acrylate, and the like; and isocyanurate (meth) acrylates such as caprolactone-modified tris- (2-acryloyloxyethyl) isocyanurate.
The content of the multifunctional (2-functional or more) acrylic ester may be, for example, 40 to 100 mass%, 50 to 100 mass%, or 60 to 100 mass% based on the total mass of the component (B1) in terms of both the effect of reducing the connection resistance and the effect of suppressing the particle flow.
(B1) The component (c) may contain a monofunctional (meth) acrylate in addition to the multifunctional (2-functional or more) (meth) acrylate. Examples of the monofunctional (meth) acrylate include (meth) acrylic acid; aliphatic (meth) acrylates such as methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, butoxyethyl (meth) acrylate, isoamyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, heptyl (meth) acrylate, octyl heptyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, hydroxyethyl (2- (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-chloro-2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, ethoxypolyethylene glycol (meth) acrylate, methoxypolypropylene glycol (meth) acrylate, ethoxypolypropylene glycol (meth) acrylate, mono (2- (meth) acryloyloxyethyl) succinate; aromatic (meth) acrylates such as benzyl (meth) acrylate, phenyl (meth) acrylate, o-biphenyl (meth) acrylate, naphthalene 1- (meth) acrylate, naphthalene 2- (meth) acrylate, phenoxyethyl (meth) acrylate, p-cumylphenoxyethyl (meth) acrylate, o-phenylphenoxyethyl (meth) acrylate, 1-naphthyloxyethyl (meth) acrylate, 2-naphthyloxyethyl (meth) acrylate, phenoxypolyethylene glycol (meth) acrylate, nonylphenoxypolyglycol (meth) acrylate, phenoxypolypropylene glycol (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, 2-hydroxy-3- (o-phenylphenoxy) propyl (meth) acrylate, 2-hydroxy-3- (1-naphthoxy) propyl (meth) acrylate, 2-hydroxy-3- (2-naphthoxy) propyl (meth) acrylate, bisphenol a epoxy (meth) acrylate; and oxetanyl group-containing (meth) acrylates such as epoxy group-containing (meth) acrylates such as glycidyl (meth) acrylate, and alicyclic epoxy group-containing (meth) acrylates such as 3, 4-epoxycyclohexylmethyl (meth) acrylate, and (3-ethyloxetan-3-yl) methyl (meth) acrylate.
The content of the monofunctional (meth) acrylate may be, for example, 0 to 60 mass%, 0 to 50 mass%, or 0 to 40 mass% based on the total mass of the component (B1).
(B) The cured product of the component (a) may have a polymerizable group that reacts in addition to the radical. The polymerizable group that reacts by a method other than the radical may be, for example, a cationic polymerizable group that reacts by a cation. Examples of the cationically polymerizable group include an epoxy group such as a glycidyl group, an alicyclic epoxy group such as a cyclohexylmethyl group, and an oxetanyl group such as an ethyloxetanylmethyl group. The cured product of the component (B) having a polymerizable group that reacts in addition to a radical can be introduced by using, for example, a (meth) acrylate having a polymerizable group that reacts in addition to a radical, such as a (meth) acrylate having an epoxy group, a (meth) acrylate having an alicyclic epoxy group, or a (meth) acrylate having an oxetanyl group, as the component (B).
As the (meth) acrylate having a polymerizable group that reacts in addition to a radical, a compound represented by the following formula (1) can be used in terms of crosslinking a radical polymerizable compound with a thermosetting component described later and forming a stronger bond at the time of bonding.
In the formula (1), R 1 Represents a hydrogen atom or a methyl group, and X represents an alkanediyl group having 1 to 3 carbon atoms. Examples of the alkanediyl group having 1 to 3 carbon atoms include methylene, ethylene and propylene. Specific examples of the compound represented by the above formula (1) include 3, 4-epoxycyclohexylmethyl (meth) acrylate.
From the viewpoint of suppressing cure shrinkage at the time of polymerization, a radical polymerizable compound (e.g., a (meth) acrylate) having a polymerizable group that reacts with other than a radical may be used in combination with a radical polymerizable compound (e.g., a (meth) acrylate) having no polymerizable group that reacts with other than a radical. From the viewpoint of improving reliability, the mass ratio of the radical polymerizable compound having a polymerizable group that reacts with the other than the radical to the total mass of the component (B1) (the mass (charged amount) of the radical polymerizable compound having a polymerizable group that reacts with the other than the radical)/(the total mass (charged amount) of the component (B1)) may be, for example, 0 or more, 0.1 or more, 0.2 or more, or 0.3 or more, 0.7 or less, 0.6 or less, 0.5 or less, or 0.4 or less, or may be 0 to 0.7, 0.1 to 0.6, 0.2 to 0.5, or 0.3 to 0.4. The mass ratio of the (meth) acrylate having a polymerizable group that reacts with the other than the radical to the (meth) acrylate having no polymerizable group that reacts with the other than the radical may be within the above range from the viewpoint of further suppressing cure shrinkage at the time of polymerization.
(B1) The component (c) may contain a radical polymerizable compound in addition to the polyfunctional (2-functional or more) and the monofunctional (meth) acrylate. Examples of the other radically polymerizable compound include maleimide compounds, vinyl ether compounds, allyl compounds, styrene derivatives, acrylamide derivatives, and imide (Nadiimide) derivatives. The content of the other radically polymerizable compound may be, for example, 0 to 40% by mass based on the total mass of the component (B1).
(B2) The components are as follows: photo radical polymerization initiator
(B2) The component (c) is a photopolymerization initiator (photo-latent radical initiator) that generates radicals by irradiation with light having a wavelength in the range of 150 to 750nm, preferably light having a wavelength in the range of 254 to 405nm, and more preferably light having a wavelength of 365nm (for example, ultraviolet light). The component (B2) may be used alone or in combination of 1 or more.
(B2) The component is decomposed by light and generates free radicals. That is, the component (B2) is a compound that generates radicals by applying light energy from the outside. (B2) The component (c) may be a compound having an oxime ester structure, a bisimidazole structure, an acridine structure, an α -aminoalkylbenzophenone structure, an aminodiphenyl ketone structure, an N-phenylglycine structure, an acylphosphine oxide structure, a benzyldimethyl ketal structure, an α -hydroxyalkylbenzophenone structure, or the like. The component (B2) may be used alone or in combination of 1 or more.
The component (B2) may be a compound having an oxime ester structure from the viewpoint of further suppressing the flow of the conductive particles, further improving the capturing rate, further suppressing the peeling after connection, and further suppressing the increase in the connection resistance. From the same viewpoint, the compound having an oxime ester structure may be a compound represented by the following formula (I).
In the formula (I), R 2 、R 3 R is R 4 Each independently represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an organic group containing an aromatic hydrocarbon group.
Specific examples of the compound having an oxime ester structure include 1-phenyl-1, 2-butanedione-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-benzoyl oxime) ], ethanone, 1- [ 9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl ] -,1- (o-acetyloxime) and the like. When such a highly active oxime ester-based photo-radical polymerization initiator is used, crosslinking can be sufficiently performed even when the amount of the component (B1) to be incorporated is small.
The content of the component (B2) may be, for example, 0.1 to 10 parts by mass, 0.3 to 7 parts by mass, or 0.5 to 5 parts by mass with respect to 100 parts by mass of the component (B1) in terms of suppressing the flow of the conductive particles.
The content of the cured product of the component (B) may be, for example, 1 part by mass or more, 5 parts by mass or more, or 10 parts by mass or more, with respect to 100 parts by mass of the total amount of components other than the component (a) in the 1 st adhesive layer, from the viewpoint of suppressing the flow of the conductive particles. The content of the cured product of the component (B) may be, for example, 30 parts by mass or less, 25 parts by mass or less, or 20 parts by mass or less, with respect to 100 parts by mass of the total amount of components other than the component (a) in the 1 st adhesive layer, from the viewpoint of exhibiting low resistance in low-voltage mounting. From these viewpoints, the content of the cured product of the component (B) may be, for example, 1 to 30 parts by mass, 5 to 25 parts by mass, or 10 to 20 parts by mass, relative to 100 parts by mass of the total amount of the components other than the component (a) in the 1 st adhesive layer. In addition, the content of the (B) component in the composition or the composition layer for forming the 1 st adhesive layer (based on the total mass of the composition or the composition layer) may be the same as the above range.
[ (C) component: thermosetting component ]
The component (C) is not particularly limited as long as it is a component (e.g., a resin component) that cures by heat, but in the case where the component (B) is a component having radical curability, the component (C) may be a component that does not have radical curability from the viewpoint of storage stability or the like. In the case where the component (B) is a component having radical curability and the component (C) is also a component having radical curability, curing of the thermosetting component is likely to be performed by radicals remaining in the 1 st adhesive layer at the time of holding. Examples of the component having no radical curability include a component having cationic curability (for example, a cationically polymerizable compound and a thermal cationic polymerization initiator) and a component having anionic curability (an anionically polymerizable compound and a thermal anionic polymerization initiator).
The component (C) may be a component having cation curability in terms of further excellent connection resistance, and may contain, for example, a cation polymerizable compound (hereinafter, sometimes referred to as a "(C1) component") and a thermal cation polymerization initiator (hereinafter, sometimes referred to as a "(C2) component"). (C) The component (C1) may be a component consisting of only the component (C2).
(C1) The components are as follows: cationically polymerizable compound
(C1) The component (C2) is a compound that is crosslinked by reacting with heat. The component (C1) is a compound having no radical polymerizable group, and the component (C1) is not included in the component (B1). The component (C1) may be used alone or in combination of 1 or more.
The component (C1) may be a compound having a cyclic ether group in view of further improving the effect of reducing the connection resistance and further improving the connection reliability. In the case of using at least 1 selected from the group consisting of oxetane compounds and alicyclic epoxy compounds among compounds having a cyclic ether group, the effect of reducing the connection resistance tends to be further improved. The (C1) component may contain both at least 1 oxetane compound and at least 1 alicyclic epoxy compound from the viewpoint of easy obtaining of a desired melt viscosity.
The oxetane compound as the component (C1) may be used without any particular limitation as long as it has an oxetanyl group and does not have a radical polymerizable group. Examples of commercial products of oxetane compounds include ETERNACOLL OXBP (trade name, 4' -bis [ (3-ethyl-3-oxetanyl) methoxymethyl ] biphenyl, manufactured by UBE INDUSTRIES, LTD.), OXSQ, OXT-121, OXT-221, OXT-101, OXT-212 (trade name, manufactured by TOAGOSEICO., LTD.), and the like. These may be used alone or in combination of 1 or more.
The alicyclic epoxy compound as the component (C1) may be used without any particular limitation as long as it has an alicyclic epoxy group (for example, epoxycyclohexyl group) and does not have a radical polymerizable group. Examples of the commercially available alicyclic epoxy compounds include EHPE3150, EHPE3150CE, and CELLOXIDE2021P, CELLOXIDE2081 (trade name, manufactured by Daicel Corporation), in addition to CELLOXIDE8010 (trade name, manufactured by bis-7-oxabicyclo [4.1.0] heptane, daicel Corporation). These may be used alone or in combination of 1 or more. As the component (C1), an epoxy compound having an aromatic hydrocarbon group such as bisphenol a epoxy resin or bisphenol F epoxy resin (for example, trade names "jER1010", "YL983U", etc. manufactured by Mitsubishi Chemical Corporation) can be used. In view of further improving the effect of reducing the connection resistance and further improving the connection reliability, an epoxy compound having an aromatic hydrocarbon group may be used in combination with an alicyclic epoxy compound.
(C2) The components are as follows: thermal cationic polymerization initiator
(C2) The component (c) is a thermal polymerization initiator (thermal latent cationic initiator) that starts polymerization by generating an acid or the like by heating. (C2) The component may be a salt compound composed of a cation and an anion. Examples of the component (C2) include a component having BF 4 - 、BR 4 - (R represents a phenyl group substituted with 2 or more fluorine atoms or 2 or more trifluoromethyl groups), PF 6 - 、SbF 6 - 、AsF 6 - Sulfonium salts, phosphonium salts, ammonium salts, diazonium salts, iodonium salts, anilinium salts, pyridinium salts, and the like of the plasma anions. These may be used alone or in combination of 1 or more.
From the viewpoint of rapid curability, the (C2) component may be, for example, a salt compound having an anion containing boron as a constituent element. Examples of such a salt compound include a compound having BF 4 - Or BR 4 - (R represents a phenyl group substituted with 2 or more fluorine atoms or 2 or more trifluoromethyl groups). The anion containing boron as a constituent element may be BR 4 - More specifically, it may be a tetrakis (pentafluorophenyl) borate.
From the viewpoint of storage stability, the component (C2) may be a salt compound having a cation represented by the following formula (II) or the following formula (III).
In the formula (II), R 5 R is R 6 Each independently represents 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 7 Represents a carbon number of 1 to up to6 alkyl.
The salt compound having a cation represented by the formula (II) may be an aromatic sulfonium salt compound (aromatic sulfonium salt type thermal acid initiator) in view of both storage stability and low-temperature activity. Namely, R in the formula (II) 5 R is R 6 At least one of them may be an organic group containing a substituted or unsubstituted aromatic hydrocarbon group. The anion in the salt compound having a cation represented by the formula (II) may be an anion containing antimony as a constituent element, and for example, may be hexafluoroantimonate (hexafluoroantimonic acid).
Specific examples of the compound having a cation represented by the formula (II) include 1-naphthylmethyl-p-hydroxyphenylsulfonium hexafluoroantimonate (SANSHIN CHEMICAL inhibitor co., ltd. Manufactured, SI-60 base), and the like.
In the formula (III), R 8 R is R 9 Each independently represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an organic group containing a substituted or unsubstituted aromatic hydrocarbon group, R 10 R is R 11 Each independently represents an alkyl group having 1 to 6 carbon atoms.
The salt compound having a cation represented by the formula (III) (quaternary ammonium salt type thermal acid initiator) has resistance against a substance that may cause curing inhibition against cationic curing, and thus may be, for example, an aniline salt compound. Namely, R in formula (III) 8 R is R 9 At least one of them may be an organic group containing a substituted or unsubstituted aromatic hydrocarbon group. Examples of the aniline salt compound include N, N-dialkylaniline salts such as N, N-dimethylaniline salt and N, N-diethylaniline salt. The anion in the salt compound having a cation represented by the formula (III) may be an anion containing boron as a constituent element, and for example, may be tetrakis (pentafluorophenyl) borate.
The compound having a cation represented by formula (III) may be an aniline salt having an anion containing boron as a constituent element. Examples of commercial products of such salt compounds include CXC-1821 (trade name, manufactured by King Industries, inc.), and the like.
The content of the component (C2) may be, for example, 0.1 to 20 parts by mass, 1 to 18 parts by mass, 3 to 15 parts by mass, or 5 to 12 parts by mass, relative to 100 parts by mass of the component (C1), in terms of securing the formability and curability of the adhesive film used to form the 1 st adhesive layer.
In terms of ensuring the curability of the adhesive film used to form the 1 st adhesive layer, the content of the component (C) may be, for example, 5 parts by mass or more, 10 parts by mass or more, 15 parts by mass or more, or 20 parts by mass or more, relative to 100 parts by mass of the total amount of components other than the component (a) in the 1 st adhesive layer. In terms of ensuring the formability of the adhesive film used to form the 1 st adhesive layer, the content of the component (C) may be, for example, 70 parts by mass or less, 60 parts by mass or less, 50 parts by mass or less, or 40 parts by mass or less, relative to 100 parts by mass of the total amount of components other than the component (a) in the 1 st adhesive layer. From these viewpoints, the content of the component (C) may be, for example, 5 to 70 parts by mass, 10 to 60 parts by mass, 15 to 50 parts by mass, or 20 to 40 parts by mass, with respect to 100 parts by mass of the total amount of components other than the component (a) in the 1 st adhesive layer. In addition, the content of the (C) component in the composition or composition layer (based on the total mass of the composition or composition layer) may be the same as the above range.
[ other Components ]
The 1 st adhesive layer 1 may contain other components in addition to the component (a), the cured product of the component (B), and the component (C). Examples of the other components include thermoplastic resins (hereinafter, sometimes referred to as "(D") components), coupling agents (hereinafter, sometimes referred to as "(E") components), and fillers (hereinafter, sometimes referred to as "(F") components).
Examples of the component (D) include phenoxy resins, polyester resins, polyamide resins, polyurethane resins, polyester amine ester resins, acrylic rubber, and epoxy resins (solid at 25 ℃). These may be used alone or in combination of 1 or more. The composition layer (1 st adhesive layer 1) can be easily formed from the composition containing the component (B) and the component (C) and the component (D). Examples of the phenoxy resin include fluorene type phenoxy resin and bisphenol a/bisphenol F copolymerized phenoxy resin.
The weight average molecular weight (Mw) of the component (D) may be, for example, 5000 to 200000, 10000 to 100000, 20000 to 80000, or 40000 to 60000 from the viewpoint of resin exclusivity at the time of mounting. The Mw is a value measured by Gel Permeation Chromatography (GPC) and converted using a ken line based on standard polystyrene.
The content of the component (D) may be, for example, 1 part by mass or more, 5 parts by mass or more, 10 parts by mass or more, or 20 parts by mass or more, 70 parts by mass or less, 60 parts by mass or less, 50 parts by mass or less, or 40 parts by mass or less, or 1 to 70 parts by mass, 5 to 60 parts by mass, 10 to 50 parts by mass, or 20 to 40 parts by mass, based on 100 parts by mass of the total amount of the components other than the component (a) in the 1 st adhesive layer. In addition, the content of the (D) component in the composition or the composition layer for forming the 1 st adhesive layer (based on the total mass of the composition or the composition layer) may be the same as the above range.
Examples of the component (E) include silane coupling agents having an organic functional group such as a (meth) acryloyl group, a mercapto group, an amino group, an imidazolyl group, and an epoxy group (such as γ -glycidoxypropyl trimethoxysilane), silane compounds such as tetraalkoxysilane, tetraalkoxy titanate derivatives, and polydialkyl titanate derivatives. These may be used alone or in combination of 1 or more. By containing the component (E) in the 1 st adhesive layer 1, the adhesion can be further improved. The component (E) may be, for example, a silane coupling agent.
The content of the component (E) may be, for example, 0.1 to 10 parts by mass based on 100 parts by mass of the total amount of components other than the component (a) in the 1 st adhesive layer. In addition, the content of the (E) component in the composition or the composition layer for forming the 1 st adhesive layer (based on the total mass of the composition or the composition layer) may be the same as the above range.
As the component (F), for example, a nonconductive filler (for example, nonconductive particles) is given. (F) The component (c) may be any of an inorganic filler and 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 particles such as silicone particles, methacrylate-butadiene-styrene particles, acrylic-silicone particles, polyamide particles, and polyimide particles. These may be used alone or in combination of 1 or more. The component (F) may be, for example, silica fine particles. The content of the component (F) may be, for example, 0.1 to 10 parts by mass based on 100 parts by mass of the total amount of components other than the component (a) in the 1 st adhesive layer. In addition, the content of the (F) component in the composition or the composition layer for forming the 1 st adhesive layer (based on the total mass of the composition or the composition layer) may be the same as the above range.
The 1 st adhesive layer 1 may further contain other additives such as a softener, an accelerator, a deterioration inhibitor, a colorant, a flame retardant, and a thixotropic agent as other components. The content of the other additive may be, for example, 0.1 to 10 parts by mass based on 100 parts by mass of the total amount of the components other than the component (a) in the 1 st adhesive layer. In addition, the content of the composition for forming the 1 st adhesive layer or other additives in the composition layer (based on the total mass of the composition or composition layer) may be the same as the above range.
In terms of transferability of the conductive particles 4 when the adhesive film for circuit connection is manufactured, the thickness d1 of the 1 st adhesive layer 1 may be, for example, 0.5 μm or more, 1.0 μm or more, or 2.0 μm or more. The thickness d1 of the 1 st adhesive layer 1 may be, for example, 5.0 μm or less, 4.0 μm or less, or 3.0 μm or less from the viewpoint of being able to further efficiently capture conductive particles at the time of connection. From these viewpoints, the thickness d1 of the 1 st adhesive layer 1 may be, for example, 0.5 to 5.0 μm, 1.0 to 4.0 μm, or 2.0 to 3.0 μm. In addition, as shown in fig. 1, in the case where a part of the conductive particles 4 is exposed from the surface of the 1 st adhesive layer 1 (e.g., protrudes toward the 2 nd adhesive layer 2 side), the distance from the surface 1a of the 1 st adhesive layer 1 on the opposite side from the 2 nd adhesive layer 2 side to the boundary S between the 1 st adhesive layer 1 and the 2 nd adhesive layer 2 located at the divided portion of the adjacent conductive particles 4, 4 (the distance denoted by d1 in fig. 1) is the thickness of the 1 st adhesive layer 1, and the exposed part of the conductive particles 4 is not included in the thickness of the 1 st adhesive layer 1.
The thickness d1 of the 1 st adhesive layer 1 is determined, for example, as follows: the adhesive film was sandwiched between 2 glasses (thickness: about 1 mm), and after injection molding with a resin composition composed of 100g of bisphenol A type epoxy resin (trade name: manufactured by jER811, mitsubishi Chemical Corporation) and 10g of curing agent (trade name: manufactured by Epomount curing agent, refine Tec Ltd. Times.), the cross-section was polished with a grinder, and the measurement was performed with a scanning electron microscope (SEM, trade name: manufactured by SE-8020,Hitachi High-Tech Science Corporation).
< 2 nd adhesive layer >
The 2 nd adhesive layer 2 is an insulating adhesive layer composed of a component having no conductivity (insulating resin component), for example. The 2 nd adhesive layer 2 contains at least the component (C).
The details (types, combinations, etc.) of the component (C) (i.e., the 2 nd thermosetting component) contained in the 2 nd adhesive layer 2 (e.g., the (C1) component, (C2) component, etc.) are the same as the details of the component (C) (i.e., the 1 st thermosetting component) contained in the 1 st adhesive layer 1, and thus detailed descriptions thereof are omitted here. The 2 nd thermosetting component may be the same as the 1 st thermosetting component or may be different from the same.
The content of the component (C) may be, for example, 5 mass% or more, 10 mass% or more, 15 mass% or more, or 20 mass% or more based on the total mass of the 2 nd adhesive layer in terms of maintaining reliability. The content of the component (C) may be, for example, 70 mass% or less, 60 mass% or less, 50 mass% or less, or 40 mass% or less based on the total mass of the 2 nd adhesive layer, in terms of preventing resin bleeding failure on the reel as one of the supply systems. From these viewpoints, the content of the component (C) may be, for example, 5 to 70 mass%, 10 to 15 mass%, 15 to 50 mass%, or 20 to 40 mass% based on the total mass of the 2 nd adhesive layer.
The 2 nd adhesive layer 2 may further contain other components ((D) component, (E) component, (F) component, other additives, and the like) in the 1 st adhesive layer 1. The other components are preferably the same as those of the 1 st adhesive layer 1.
The content of the component (D) may be, for example, 1 mass% or more, 5 mass% or more, or 10 mass% or more, 80 mass% or less, 60 mass% or less, or 40 mass% or less, or 1 to 80 mass%, 5 to 60 mass%, or 10 to 40 mass% based on the total mass of the 2 nd adhesive layer.
The content of the component (E) may be, for example, 0.1 to 10 mass% based on the total mass of the 2 nd adhesive layer.
The content of the component (F) may be, for example, 1 mass% or more, 10 mass% or more, or 30 mass% or more, 90 mass% or less, 70 mass% or less, or 50 mass% or less, or 1 to 90 mass% or less, 10 to 70 mass% or less, or 30 to 50 mass% based on the total mass of the 2 nd adhesive layer.
The content of the other additive may be, for example, 0.1 to 10 mass% based on the total mass of the 2 nd adhesive layer.
The thickness d2 of the 2 nd adhesive layer 2 may be appropriately set according to the height of the electrode of the connected circuit component, etc. The thickness d2 of the 2 nd adhesive layer 2 may be, for example, 2 μm or more, 5 μm or more, or 10 μm or more, 30 μm or less, 20 μm or less, or 15 μm or less, or 2 to 30 μm, 5 to 20 μm, or 10 to 15 μm in order to sufficiently fill the space between the electrodes and seal the electrodes, thereby obtaining a more excellent connection reliability. In addition, as shown in fig. 1, when a part of the conductive particles 4 is exposed from the surface of the 1 st adhesive layer 1 (for example, protrudes toward the 2 nd adhesive layer 2 side), the distance from the surface 2a of the 2 nd adhesive layer 2 on the opposite side to the 1 st adhesive layer 1 side to the boundary S between the 1 st adhesive layer 1 and the 2 nd adhesive layer 2 located at the divided portion of the adjacent conductive particles 4, 4 (the distance denoted by d2 in fig. 1) is the thickness of the 2 nd adhesive layer 2. The thickness d2 of the 2 nd adhesive layer 2 can be obtained, for example, in the same manner as the method for measuring the thickness d1 of the 1 st adhesive layer 1 described above.
The thickness of the circuit-connecting adhesive film 10A (the total of the thicknesses of all layers constituting the circuit-connecting adhesive film 10A) may be, for example, 2.5 μm or more, 6 μm or more, or 12 μm or more, 35 μm or less, 24 μm or less, or 18 μm or less, or 2.5 to 35 μm, 6 to 24 μm, or 12 to 24 μm.
The adhesive film for circuit connection 10A is an adhesive film for circuit connection. The circuit-connecting adhesive film 10A may or may not have anisotropic conductivity. That is, the circuit-connecting adhesive film may be an anisotropic conductive adhesive film or a non-anisotropic conductive (e.g., isotropic conductive) adhesive film. The adhesive film 10A for circuit connection is disposed between the surface provided with the 1 st electrode of the 1 st circuit component having the 1 st electrode and the surface provided with the 2 nd electrode of the 2 nd circuit component having the 2 nd electrode, and can be used as follows: the laminated body including the 1 st circuit member, the circuit-connecting adhesive film 10A, and the 2 nd circuit member is heated in a state of being pressed in the thickness direction of the laminated body, whereby the 1 st electrode and the 2 nd electrode are electrically connected to each other via the conductive particles (or a melt-solidified product of the conductive particles) and the 1 st circuit member and the 2 nd circuit member are bonded. The term "anisotropic conductivity" as used herein means conduction in the pressing direction and insulation in the non-pressing direction.
According to the adhesive film 10A for circuit connection, the fluidity of the conductive particles at the time of connection is suppressed by the cured product of the photocurable component while the exclusivity of the resin at the time of connection is ensured by the thermosetting component, so that the capturing rate of the conductive particles between the connected electrodes can be improved. Therefore, according to the adhesive film 10A for circuit connection, a connection structure having less occurrence of short-circuiting and excellent conductivity between electrodes can be obtained.
The adhesive film for circuit connection of the embodiment has been described above, but the present invention is not limited to the above embodiment.
For example, as shown in fig. 4, the adhesive film 10B for circuit connection may be provided with the 3 rd adhesive layer 5 containing the (C) component (thermosetting component) on the opposite side of the 1 st adhesive layer 1 from the 2 nd adhesive layer 2. The 3 rd adhesive layer 5 is an insulating adhesive layer composed of a component having no conductivity (insulating resin component), for example. The circuit-connecting adhesive film 10B has the same structure as the circuit-connecting adhesive film 10A except that the 3 rd adhesive layer 5 is laminated.
The details of the component (C) (hereinafter also referred to as "3 rd thermosetting component") contained in the 3 rd adhesive layer 5 are the same as those of the thermosetting component described above. For example, the 3 rd thermosetting component may include a (C1) component (i.e., a cationically polymerizable compound) and a (C2) component (i.e., a thermal cationic polymerization initiator). The (C1) component and the (C2) component used in the 3 rd thermosetting component are the same as the (C1) component and the (C2) component used in the 1 st thermosetting component, and thus detailed description thereof is omitted here. The 3 rd thermosetting component may be the same as the 1 st thermosetting component or may be different from the same. The 3 rd thermosetting component may be the same as the 2 nd thermosetting component or may be different.
The content of the component (C) may be, for example, 5 mass% or more, 10 mass% or more, 15 mass% or more, or 20 mass% or more based on the total mass of the 3 rd adhesive layer in terms of imparting good transferability and peeling resistance. The content of the component (C) may be, for example, 70 mass% or less, 60 mass% or less, 50 mass% or less, or 40 mass% or less based on the total mass of the 3 rd adhesive layer in terms of imparting good half-cut property and blocking resistance (suppressing resin bleed-out of the roll). From these viewpoints, the content of the component (C) may be, for example, 5 to 70 mass%, 10 to 60 mass%, 15 to 50 mass%, or 20 to 40 mass% based on the total mass of the 3 rd adhesive layer.
The 3 rd adhesive layer 5 may further contain other components in the 1 st adhesive layer 1. The other components are preferably the same as those of the 1 st adhesive layer 1.
The content of the component (D) may be, for example, 10 mass% or more, 20 mass% or more, or 30 mass% or more, 80 mass% or less, 70 mass% or less, or 60 mass% or less, or 10 to 80 mass%, 20 to 70 mass%, or 30 to 60 mass% based on the total mass of the 3 rd adhesive layer.
The content of the component (E) may be, for example, 0.1 to 10 mass% based on the total mass of the 3 rd adhesive layer.
The content of the component (F) may be, for example, 1 mass% or more, 3 mass% or more, or 5 mass% or more, 50 mass% or less, 40 mass% or less, or 30 mass% or less, or 1 to 50 mass%, 3 to 40 mass%, or 5 to 30 mass% based on the total mass of the 3 rd adhesive layer.
The content of the other additive may be, for example, 0.1 to 10 mass% based on the total mass of the 3 rd adhesive layer.
The thickness d3 of the 3 rd adhesive layer 5 may be appropriately set according to the height of the electrode of the bonded circuit member, etc. The thickness d3 of the 3 rd adhesive layer 5 may be, for example, 0.1 μm or more, 0.5 μm or more, or 1.0 μm or more, 10 μm or less, 5.0 μm or less, or 2.5 μm or less, or 0.1 to 10 μm, 0.5 to 5.0 μm, or 1.0 to 2.5 μm in order to sufficiently fill the space between the electrodes and seal the electrodes, thereby obtaining a more excellent connection reliability. The thickness d3 of the 3 rd adhesive layer 5 is a distance (a distance denoted by d3 in fig. 4) from the surface 5a of the 3 rd adhesive layer 5 on the side opposite to the 1 st adhesive layer 1 side to the surface 1a of the 1 st adhesive layer 1 on the side opposite to the 2 nd adhesive layer 2 side, and can be obtained, for example, in the same manner as the above-described method of measuring the thickness d1 of the 1 st adhesive layer 1.
In the case where the circuit-connecting adhesive film has layers other than the 1 st adhesive layer and the 2 nd adhesive layer (for example, the 3 rd adhesive layer), the thickness of the circuit-connecting adhesive film (the total of the thicknesses of all the layers constituting the circuit-connecting adhesive film) may be the same as the range in which the thickness of the above-described circuit-connecting adhesive film 10A is desirable.
Method for producing adhesive film for circuit connection
The method for manufacturing the adhesive film for circuit connection comprises the following steps: preparing a substrate having a plurality of recesses on a surface thereof and conductive particles disposed in at least a part of the plurality of recesses (a preparation step); the conductive particles are transferred to the composition layer by providing the composition layer containing the photocurable component and the 1 st thermosetting component on the surface (surface where the concave portion is formed) of the substrate (transfer step); forming a 1 st adhesive layer containing a cured product of a plurality of conductive particles and a photocurable component and a 1 st thermosetting component by irradiating the composition layer with light (light irradiation step); and disposing a 2 nd adhesive layer containing a 2 nd thermosetting component on one surface of the 1 st adhesive layer (lamination step).
Hereinafter, a method for producing the adhesive film for circuit connection 10A will be described with reference to fig. 5 to 10 by way of example.
Fig. 5 is a view schematically showing a longitudinal section of a substrate used in the method for manufacturing the adhesive film for circuit connection 10A. Fig. 6 is a diagram showing a modification of the cross-sectional shape of the recess of the base body of fig. 5. Fig. 7 is a cross-sectional view schematically showing a state in which conductive particles 4 are disposed in the concave portion of the base body of fig. 5. Fig. 8 is a cross-sectional view schematically showing an example of the preparation process. Fig. 9 is a cross-sectional view schematically showing an example of the transfer process. Fig. 10 is a cross-sectional view schematically showing an example of the light irradiation step.
(preparation step)
In the preparation step, first, a substrate 6 having a plurality of recesses 7 on the surface thereof is prepared (see fig. 5). The base body 6 has a plurality of recesses 7. The plurality of concave portions 7 are arranged regularly in a predetermined pattern (for example, a pattern corresponding to an electrode pattern of the circuit member), for example. When the concave portions 7 are arranged in a predetermined pattern, the conductive particles 4 are transferred to the composition layer in the predetermined pattern. Thus, the adhesive film 10A for circuit connection in which the conductive particles 4 are regularly arranged in a predetermined pattern (such as the pattern shown in fig. 2 and 3) can be obtained.
As shown in fig. 5, the recess 7 of the base 6 may be formed in a tapered shape in which an opening area is enlarged from the bottom 7a side of the recess 7 toward the surface 6a side of the base 6, for example. That is, the width of the bottom 7a of the recess 7 (width a in fig. 5) may be narrower than the width of the opening of the recess 7 (width b in fig. 5). The dimensions (width a, width b, volume, taper angle, depth, etc.) of the recess 7 can be set according to the dimensions of the target conductive particles and the positions of the conductive particles in the adhesive film for circuit connection. For example, the width (width b) of the opening of the recess 7 may be larger than the maximum particle diameter of the conductive particle 4 or may be smaller than 2 times the maximum particle diameter of the conductive particle.
The shape of the recess 7 (the cross-sectional shape of the recess 7) in the longitudinal section of the base 6 may be, for example, a shape as shown in fig. 6 (a) to (h). Any of the cross-sectional shapes shown in fig. 6 (a) to (h) is such that the width (width b) of the opening of the recess 7 is the largest width among the cross-sectional shapes. This facilitates removal of the conductive particles disposed in the recess 7, and improves workability.
The shape of the opening of the recess 7 may be circular, elliptical, triangular, quadrangular, polygonal, or the like.
The recess 7 of the base 6 can be formed by a known method such as photolithography and machining. In these methods, the size and shape of the recess can be freely designed.
As a material constituting the substrate 6, for example, inorganic materials such as silicon, various ceramics, glass, metal such as stainless steel, and organic materials such as various resins can be used. As described later, in the manufacturing method of the present embodiment, the conductive particles 4 can be disposed in the concave portion 7 of the base 6 by forming the conductive particles 4 in the concave portion 7 of the base 6, but in this case, the base 6 may have heat resistance that does not deteriorate at the melting temperature of the fine particles (for example, solder fine particles) for forming the conductive particles 4.
Next, the conductive particles 4 (the above component (a)) are disposed (housed) in at least a part (a part or all) of the plurality of recesses 7 of the base 6 (see fig. 7).
The method of disposing the conductive particles 4 is not particularly limited. The configuration method may be either dry or wet. For example, by disposing the conductive particles 4 on the surface 6a of the substrate 6 and scraping the surface 6a of the substrate 6 with a squeegee or a slightly sticking roller, the unnecessary conductive particles 4 can be removed and the conductive particles 4 can be disposed in the concave portions 7. When the width b of the opening of the recess 7 is larger than the depth of the recess 7, the conductive particles may fly out of the opening of the recess 7. When the squeegee is used, conductive particles flying out from the opening of the recess 7 are removed. As a method for removing the excessive conductive particles, a method of blowing compressed air and scraping the surface 6a of the substrate 6 with a nonwoven fabric or a fiber bundle may be mentioned. These methods are preferable in terms of handling easily deformable particles (e.g., solder particles) as conductive particles because they are weak in physical force as compared with a squeegee.
When solder particles are used as the conductive particles 4, the conductive particles 4 can be arranged in the recesses 7 by forming the conductive particles 4 (solder particles) in the recesses 7 of the base 6. Specifically, for example, as shown in fig. 8 (a) to (b), the fine particles 8 (solder fine particles) for forming the conductive particles 4 are stored in the concave portion 7, and then the fine particles 8 stored in the concave portion 7 are melted, whereby the conductive particles 4 can be formed in the concave portion 7. The fine particles 8 accommodated in the recess 7 are integrated by melting and are spheroidized by surface tension. At this time, in the contact portion with the bottom 7a of the recess 7, the molten metal takes a shape following the bottom 7 a. Therefore, for example, in the case where the bottom 7a of the recess 7 has a flat shape as shown in fig. 8 (a), the conductive particles 4 have a flat surface 4a in a part of the surface shown in fig. 8 (b).
The fine particles 8 may be accommodated in the concave portion 7, and the variation in the particle size distribution may be large, or the shape may be deformed.
As a method of melting the fine particles 8 stored in the recess 7, there is a method of heating the fine particles 8 to a temperature equal to or higher than the melting point of the material forming the fine particles. The particles 8 may not be melted, wet-spread or both of them even when heated at a temperature equal to or higher than the melting point due to the influence of the oxide film. Therefore, the fine particles 8 may be exposed to a reducing atmosphere, and the oxide film on the surface of the fine particles 8 may be removed and then heated to a temperature equal to or higher than the melting point of the fine particles 8. This facilitates melting and wetting of the fine particles 8, and thus the fine particles are combined. From the same point of view, the melting of the fine particles 8 may be performed under a reducing atmosphere.
The method of setting to the reducing atmosphere is not particularly limited as long as the above-described effects can be obtained, and there are methods using hydrogen gas, hydrogen radicals, formic acid gas, and the like, for example. For example, the fine particles 8 can be melted in a reducing atmosphere by using a hydrogen reducing furnace, a hydrogen radical reducing furnace, a formic acid reducing furnace, or a conveyor furnace or a continuous furnace of these. These devices can be provided with a heating device, a chamber filled with an inert gas (nitrogen gas, argon gas, or the like), a mechanism for setting the chamber to a vacuum, or the like in the furnace, whereby the reducing gas can be controlled more easily. Further, if the inside of the chamber can be evacuated, the fine particles 8 can be melted and combined, and then the voids can be removed by reducing the pressure, whereby the conductive particles 4 having further excellent connection stability can be obtained.
The configuration file such as reduction, dissolution conditions, temperature, and adjustment of the furnace atmosphere of the fine particles 8 can be appropriately set in consideration of the melting point, particle size, size of the concave portion, material of the substrate 6, and the like of the fine particles 8.
According to the above method, the conductive particles 4 having a substantially uniform size can be formed regardless of the material and shape of the fine particles 8. Since the size and shape of the conductive particles 4 depend on the amount of the fine particles 8 stored in the concave portions 7, the shape of the concave portions 7, and the like, the size and shape of the conductive particles 4 can be freely designed by designing the concave portions 7 (adjusting the size, shape, and the like of the concave portions), and conductive particles having a target particle size distribution (for example, conductive particles having an average particle diameter of 1 to 30 μm and a c.v. value of 20% or less) can be easily prepared.
The above method is particularly suitable for the case where the conductive particles 4 are indium-based solder particles. Indium solder can be deposited by plating, but is not easily deposited in the form of particles, and is a soft and difficult-to-handle material. However, in the above method, indium-based solder particles having a substantially uniform particle diameter can be easily produced by using indium-based solder particles as a raw material.
After the conductive particles 4 are disposed in the recess 7, the base 6 can be operated in a state where the conductive particles 4 are disposed (housed) in the recess 7. For example, when the substrate 6 is transported or stored in a state where the conductive particles 4 are disposed (stored) in the recess 7, deformation of the conductive particles 4 (particularly, soft conductive particles such as solder particles) can be prevented. In addition, since the conductive particles 4 are easily taken out in a state where the conductive particles 4 are disposed (housed) in the concave portions 7, deformation such as recovery and surface treatment of the conductive particles 4 is also easily prevented.
(transfer step)
In the transfer step, the conductive particles 4 are transferred to the composition layer 9 by providing the composition layer 9 containing the photocurable component (B) and the 1 st thermosetting component (C) on the surface (surface on which the concave portion 7 is formed) of the substrate 6 (see fig. 9).
Specifically, first, after the laminated film 12 is obtained by forming the composition layer 9 containing the component (B) and the component (C) on the support 11, the surface 6a of the base 6 on which the concave portion 7 is formed (the surface of the base 6) is opposed to the surface of the laminated film 12 on the composition layer 9 side (the surface 9a of the composition layer 9 on the opposite side to the support 11), and the base 6 and the composition layer 9 are brought close to each other (see fig. 9 (a)). Next, the laminated film 12 is bonded to the substrate 6, and the composition layer 9 is brought into contact with the surface (surface on which the concave portion 7 is formed) 6a of the substrate 6, whereby the conductive particles 4 are transferred to the composition layer 9. Thus, the particle transfer layer 13 including the composition layer 9 and at least a part of the conductive particles 4 embedded in the composition layer 9 can be obtained (see fig. 9 (b)). At this time, when the bottom of the recess 7 is flat, the conductive particles 4 have a flat surface portion 4a corresponding to the shape of the bottom of the recess 7, and are disposed in the composition layer 9 in a state where the flat surface portion 4a faces the opposite side of the support 11.
The composition layer 9 can be formed using a varnish composition (varnish-like 1 st adhesive composition) prepared by dissolving or dispersing the component (B) and the component (C) and other components added as necessary in an organic medium by stirring, mixing, kneading, or the like. Specifically, for example, the composition layer 9 can be formed by applying the varnish composition on the support 11 (for example, a substrate subjected to a mold release treatment) using an air knife coater, a roll coater, an applicator, a corner-roll coater, a die coater, or the like, and then volatilizing the organic medium by heating. In this case, the thickness of the 1 st adhesive layer (1 st adhesive film) to be finally obtained can be adjusted by adjusting the coating amount of the varnish composition.
The organic medium used for preparing the varnish composition is not particularly limited as long as it has a property of being able to substantially uniformly dissolve or disperse each component. Examples of such an organic medium include toluene, acetone, methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate, propyl acetate, butyl acetate, and the like. These organic mediums can be used singly or in combination of 2 or more. The stirring and mixing or kneading in the preparation of the varnish composition can be performed using, for example, a stirrer, a grinder, 3 rolls, a ball mill, a bead mill, a homogenizing and dispersing machine, or the like.
The support 11 is not particularly limited as long as it has heat resistance capable of withstanding the heating conditions at the time of volatilizing the organic medium. The support 11 may be a plastic film or a metal foil. As the support 11, for example, a base material (e.g., film) using, as a constituent material, stretched polypropylene (OPP), polyethylene terephthalate (PET), polyethylene naphthalate, polyethylene isophthalate, polybutylene terephthalate, polyolefin, polyacetate, polycarbonate, polyphenylene sulfide, polyamide, polyimide, cellulose, ethylene-vinyl acetate copolymer, polyvinyl chloride, polyvinylidene chloride, a synthetic rubber system, a liquid crystal polymer, or the like can be used.
The heating conditions for volatilizing the organic medium from the varnish composition applied on the substrate can be appropriately set according to the organic medium or the like used. The heating conditions may be, for example, 40 to 120℃and 0.1 to 10 minutes.
Examples of the method for bonding the laminated film 12 to the substrate 6 include hot pressing, roll lamination, and vacuum lamination. The lamination can be performed, for example, under a temperature condition of 0 to 80 ℃.
In the transfer step, the varnish composition may be directly applied to the substrate 6 to form the composition layer 9, but the use of the laminated film 12 as described above facilitates the formation of the particle transfer layer 13 in which the support 11, the composition layer 9, and the conductive particles 4 are integrally formed, and thus the light irradiation step described below can be easily performed.
(light irradiation step)
In the light irradiation step, the composition layer 9 (particle transfer layer 13) is irradiated with light (active light), so that the component (B) in the composition layer 9 is cured, thereby forming the 1 st adhesive layer 1 (see fig. 10).
As the irradiation of light, irradiation light (for example, ultraviolet light) including a wavelength in the range of 150 to 750nm can be used. The irradiation of light can be performed using, for example, a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a xenon lamp, a metal halide lamp, an LED light source, or the like. The cumulative amount of light to be irradiated can be appropriately set, but may be, for example, 500 to 3000mJ/cm 2 。
As shown by the arrow in fig. 10 (a), light is irradiated from the side opposite to the support 11 (the side of the composition layer 9 to which the conductive particles 4 are transferred), but in the case where the support 11 transmits light, light may be irradiated from the support 11 side. In fig. 10 (a), the substrate 6 and the particle transfer layer 13 are separated and then irradiated with light, but the substrate 6 may be irradiated with light before separation. At this time, light may be irradiated after the support 11 is peeled off.
(lamination step)
In the lamination step, the 2 nd adhesive layer 2 is provided on the surface of the 1 st adhesive layer 1 on the opposite side (the side of the composition layer 9 to which the conductive particles 4 are transferred) from the support 11. Thus, the adhesive film 10A for circuit connection shown in fig. 1 can be obtained.
The 2 nd adhesive layer 2 may be provided on the 1 st adhesive layer 1 in the same manner as the method of providing the composition layer 9 on the substrate 6, except that a varnish composition (varnish-like 2 nd adhesive composition) prepared by dissolving or dispersing the 2 nd thermosetting component (the above (C) component) and other components added as needed in an organic medium by stirring, mixing, etc. is used instead of the varnish-like 1 st adhesive composition. That is, the 2 nd adhesive layer 2 may be provided on the 1 st adhesive layer 1 by bonding a laminated film obtained by forming the 2 nd adhesive layer 2 on the support to the 1 st adhesive layer 1, or the 2 nd adhesive layer 2 may be provided on the 1 st adhesive layer 1 by directly applying a 2 nd adhesive composition in a varnish form to the 1 st adhesive layer 1.
In the lamination step, by providing the 2 nd adhesive layer 2 on the surface opposite to the support 11 as described above, it is possible to expect improvement in the adhesion of the adhesive film for circuit connection to the circuit member and suppression of peeling at the time of connection. In the lamination step, the 2 nd adhesive layer 2 may be provided on the surface of the side on which the support 11 is provided after the support 11 is peeled off. In this case, the lamination step may be performed before the light irradiation step or before the transfer step.
The method for producing the adhesive film for circuit connection 10A according to the embodiment has been described above as an example, but the present invention is not limited to the above-described embodiment.
For example, the method for producing an adhesive film for circuit connection may further include a step of providing a 3 rd adhesive layer on a surface of the 1 st adhesive layer opposite to the 2 nd adhesive layer (2 nd lamination step). In this method, an adhesive film for circuit connection (for example, an adhesive film for circuit connection 10B shown in fig. 4) further provided with the 3 rd adhesive layer can be obtained.
In the 2 nd lamination step, a composition (3 rd adhesive composition) containing the 3 rd thermosetting component (the above (C) component) and other components added as needed is provided instead of the 2 nd adhesive composition, and the 3 rd adhesive layer may be provided on the 1 st adhesive layer in the same manner as in the above lamination step (1 st lamination step) for providing the 2 nd adhesive layer. The 2 nd lamination step may be performed before the 1 st lamination step.
Connection structure and method for manufacturing the same
Hereinafter, a connection structure (circuit connection structure) and a method for manufacturing the same will be described by way of example using the above-described adhesive film for circuit connection 10A as a circuit connection material.
Fig. 11 is a schematic cross-sectional view showing an embodiment of the connection structure. As shown in fig. 11, the connection structure 100 includes: a 1 st circuit part 23 having a 1 st circuit substrate 21 and a 1 st electrode 22 formed on a main surface 21a of the 1 st circuit substrate 21; a 2 nd circuit member 26 having a 2 nd circuit substrate 24 and a 2 nd electrode 25 formed on a main surface 24a of the 2 nd circuit substrate 24; and a connection portion 27 including a cured body of the adhesive film 10A for circuit connection, which electrically connects the 1 st electrode 22 and the 2 nd electrode 25 to each other via the conductive particles 4 (or a melt-cured product of the conductive particles 4) and bonds the 1 st circuit member 23 and the 2 nd circuit member 26.
The 1 st circuit member 23 and the 2 nd circuit member 26 may be the same as each other or may be different from each other. The 1 st circuit member 23 and the 2 nd circuit member 26 may be glass substrates or plastic substrates 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. The 1 st and 2 nd circuit substrates 21 and 24 may be formed of an inorganic material such as a semiconductor, glass, or ceramic, an organic material such as polyimide or polycarbonate, or a composite material such as glass/epoxy. The 1 st circuit substrate 21 may be a plastic substrate. The 1 st circuit member 23 may be, for example, a plastic substrate (a plastic substrate having an organic material such as polyimide, polycarbonate, polyethylene terephthalate, or cyclic olefin polymer as a constituent material) on which a circuit electrode is formed, and the 2 nd circuit member 26 may be, for example, an IC wafer such as a driving IC. The plastic substrate on which the electrodes are formed may be a plastic substrate on which a display region is formed by regularly arranging pixel driving circuits such as organic TFTs or a plurality of organic EL elements R, G, B in a matrix, for example.
The 1 st electrode 22 and the 2 nd electrode 25 may be electrodes containing metals such as gold, silver, tin, ruthenium, rhodium, palladium, osmium, iridium, platinum, copper, aluminum, molybdenum, titanium, or the like, oxides such as Indium Tin Oxide (ITO), indium Zinc Oxide (IZO), indium Gallium Zinc Oxide (IGZO), or the like. The 1 st electrode 22 and the 2 nd electrode 25 may be electrodes formed by stacking 2 or more of these metals, oxides, and the like. The number of electrodes formed by stacking 2 or more kinds may be 2 or more, or 3 or more. The 1 st electrode 22 and the 2 nd electrode 25 may be circuit electrodes or bump electrodes. In fig. 11, the 1 st electrode 22 is a circuit electrode, and the 2 nd electrode 25 is a bump electrode.
The connection portion 27 includes, for example: a 1 st region 28 which is located on the 1 st circuit member 23 side in a direction in which the 1 st circuit member 23 and the 2 nd circuit member 26 face each other (hereinafter, referred to as a "facing direction"), and which contains a cured product of the component (B) and a cured product of the component (C) other than the conductive particles 4 in the 1 st adhesive layer; a 2 nd region 29 which is located on the 2 nd circuit member 26 side in the opposing direction and contains a cured product of the (C) component or the like in the 2 nd adhesive layer; and conductive particles 4 (or a melt-solidified product of the conductive particles 4) interposed at least between the 1 st electrode 22 and the 2 nd electrode 25 to electrically connect the 1 st electrode 22 and the 2 nd electrode 25 to each other. The connection portion 27 does not necessarily have 2 distinct regions between the 1 st region 28 and the 2 nd region 29, and 1 region may be formed by mixing a cured product derived from the 1 st adhesive layer and a cured product derived from the 2 nd adhesive layer.
Examples of the connection structure include a flexible organic electroluminescent color display (organic EL display) in which a plastic substrate on which organic EL elements are regularly arranged is connected to a driving circuit element as an image display driver, and a touch panel in which a plastic substrate on which organic EL elements are regularly arranged is connected to an input element such as a touch panel. The connection structure can be applied to various monitors such as smart phones, tablet computers, televisions, navigation systems of vehicles, wearable terminals and the like; furniture; household appliances; daily necessities, and the like.
Fig. 12 is a schematic cross-sectional view showing an embodiment of a method for manufacturing the connection structure 100. Fig. 12 (a) and 12 (b) are schematic cross-sectional views showing the respective steps. As shown in fig. 12, the method for manufacturing the connection structure 100 includes the steps of: the adhesive film 10A for circuit connection is disposed between the surface of the 1 st circuit member 23 on which the 1 st electrode 22 is provided and the surface of the 2 nd circuit member 26 on which the 2 nd electrode 25 is provided; and heating the laminate including the 1 st circuit member 23, the circuit-connecting adhesive film 10A, and the 2 nd circuit member 26 in a state of being pressed in the thickness direction of the laminate, thereby electrically connecting the 1 st electrode 22 and the 2 nd electrode 25 to each other via the conductive particles 4 (or a melt-solidified product of the conductive particles 4) and bonding the 1 st circuit member 23 and the 2 nd circuit member 26.
Specifically, first, a 1 st circuit component 23 including the 1 st circuit board 21 and the 1 st electrode 22 formed on the main surface 21a of the 1 st circuit board 21 and a 2 nd circuit component 26 including the 2 nd circuit board 24 and the 2 nd electrode 25 formed on the main surface 24a of the 2 nd circuit board 24 are prepared.
Next, the 1 st circuit member 23 and the 2 nd circuit member 26 are arranged so that the 1 st electrode 22 and the 2 nd electrode 25 face each other, and the adhesive film 10A for circuit connection is arranged between the 1 st circuit member 23 and the 2 nd circuit member 26. For example, as shown in fig. 12 (a), the 1 st adhesive layer 1 side is opposed to the main surface 21a of the 1 st circuit board 21, and the circuit-connecting adhesive film 10A is laminated on the 1 st circuit member 23. Next, the 2 nd circuit member 26 is disposed on the 1 st circuit member 23 on which the circuit connecting adhesive film 10A is laminated so that the 1 st electrode 22 on the 1 st circuit substrate 21 and the 2 nd electrode 25 on the 2 nd circuit substrate 24 face each other.
As shown in fig. 12 (b), the laminated body formed by laminating the 1 st circuit member 23, the circuit connecting adhesive film 10A, and the 2 nd circuit member 26 in this order is heated in a state of being pressed in the thickness direction of the laminated body, and the 1 st circuit member 23 and the 2 nd circuit member 26 are thermally pressed against each other. At this time, as shown by arrows in fig. 12 b, the flowable uncured thermosetting component contained in the 1 st adhesive layer 1 and the 2 nd adhesive layer 2 flows to fill the gaps of the electrodes adjacent to each other (the gaps between the 1 st electrode 22 and the gaps between the 2 nd electrode 25), and is cured by the above-mentioned heating. Thus, the 1 st electrode 22 and the 2 nd electrode 25 are electrically connected to each other via the conductive particles 4, and the 1 st circuit member 23 and the 2 nd circuit member 26 are bonded to each other, whereby the connection structure 100 shown in fig. 11 can be obtained.
In the method for manufacturing the connection structure 100, since a part of the 1 st adhesive layer 1 is cured by light irradiation, the flow of the conductive particles in the 1 st adhesive layer 1 is suppressed, and therefore the conductive particles can be efficiently and effectively captured between the opposing electrodes. Further, since the thermosetting component contained in the 1 st adhesive layer 1 and the 2 nd adhesive layer 2 flows at the time of thermocompression bonding, the resin is less likely to be interposed between the conductive particles 4 and the electrodes (1 st electrode and 2 nd electrode) after the connection, and the connection resistance between the 1 st electrode 22 and the 2 nd electrode 25 facing each other can be reduced.
When solder particles are used as the conductive particles, the solder particles are melted and accumulated between the 1 st electrode 22 and the 2 nd electrode 25 to form a solder layer, and then the solder layer is cooled, whereby the solder layer is fixed between the 1 st electrode 22 and the 2 nd electrode 25, and the 1 st electrode 22 and the 2 nd electrode 25 are electrically connected to each other.
The heating temperature at the time of connection can be set appropriately, but may be, for example, 50 to 190 ℃. When solder particles are used as the conductive particles, the temperature at which the solder particles can be melted (for example, a temperature higher than the melting point of the solder particles) may be, for example, 130 to 260 ℃. The pressurization is not particularly limited as long as it does not damage the adherend, but in the case of COP mounting, for example, the area conversion pressure on the bump electrode may be 0.1 to 50MPa, 40MPa or less, or 0.1 to 40MPa. In the case of COG mounting, for example, the area conversion pressure on the bump electrode may be 10 to 100MPa. These heating and pressurizing times may be in the range of 0.5 to 120 seconds.
Examples
Hereinafter, the present invention will be described in more detail with reference to examples and comparative examples, but the present invention is not limited to the following examples.
In examples and comparative examples, the materials shown below were used as the (B1) component, (B2) component, (C1) component, (C2) component, (C3) component, (C4) component, (D) component, (E) component and (F) component.
(B1) The components are as follows: radical polymerizable compound
NK Ester A-BPEF (9, 9-bis [4- (2-acryloyloxyethoxy) phenyl ] fluorene, SHIN-NAKAMURA CHEMICAL CO, LTD. Manufactured)
RIPOXY VR-90 (bisphenol A epoxy methacrylate, manufactured by SHOWA DENKO K.K.)
CYCLOMER M100 (3, 4-epoxycyclohexylmethyl methacrylate, manufactured by Daicel Corporation)
A-1000 (polyethylene glycol diacrylate, SHIN-NAKAMURA CHEMICAL CO, LTD.)
A9300-1CL (caprolactone-modified tris- (2-acryloyloxyethyl) isocyanurate, SHIN-NAKAMURA CHEMICAL CO, LTD.)
(B2) The components are as follows: photo radical polymerization initiator
Irgacure OXE-02 (1- [ 9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl ] -ethanone 1- (O-acetyl oxime), manufactured by BASF Japan Ltd.)
Omnirad907 (2-methyl-1- [4- (methylthio) phenyl ] -2-oral terminal propan-1-one, manufactured by IGM RESINS B.V. Co., ltd.)
(C1) The components are as follows: cationically polymerizable compound
ETERNACOLL OXBP (4, 4' -bis [ (3-ethyl-3-oxetanyl) methoxymethyl ] biphenyl, manufactured by UBE INDUSTRIES, LTD.)
CELLOXIDE8010 (bis-7-oxabicyclo [4.1.0] heptane, manufactured by Daicel Corporation)
jER1010 (bisphenol A type epoxy resin manufactured by Mitsubishi Chemical Corporation)
YL983U (bisphenol F type epoxy resin manufactured by Mitsubishi Chemical Corporation)
(C2) The components are as follows: thermal cationic polymerization initiator (thermal latent cationic initiator)
CXC-1821 (quaternary ammonium salt type thermal acid initiator, manufactured by King Industries Co., ltd.),
SI-60L (aromatic sulfonium salt type thermal acid initiator, SANSHIN CHEMICAL INDUSTRY CO., LTD.,
(C3) The components are as follows: anionically polymerizable compounds
HP-4032D (1, 6-bis (oxiranylmethoxy) naphthalene, DIC CORPORATION)
(C4) The components are as follows: thermal anionic polymerization initiator (thermal latent anionic initiator)
HX-3941HP (microcapsule type imidazole curing accelerator manufactured by Asahi Kasei Corporation)
(D) The components are as follows: thermoplastic resin
P-1: fluorene type phenoxy resin synthesized by the method described later
YP-70 (bisphenol A/bisphenol F copolymerized phenoxy resin, NIPPON STEEL Chemical & Material Co., ltd.)
(E) The components are as follows: coupling agent
KBM-403 (gamma-glycidoxypropyl trimethoxysilane, shin-Etsu Chemical Co., ltd.)
(F) The components are as follows: filler (B)
AEROSIL R805 (hydrolysis product of trimethoxyoctylsilane and silica (silica particles), manufactured by Evonik Industries AG, using a solvent diluted to 10% by mass of nonvolatile matter)
(Synthesis of P-1)
45g of 4,4'- (9-fluorenylidene) -diphenol (manufactured by Sigma-Aldrich Japan K.K.) and 50g of 3,3',5 '-tetramethyl bisphenol diglycidyl ether (manufactured by YX-4000H,Mitsubishi Chemical Corporation) were dissolved in 1000mL of N-methylpyrrolidone in a three-necked flask equipped with a Dyer's cooling tube, a calcium chloride tube, and a Teflon stirring bar ("Teflon" is a registered trademark) connected to a stirring motor, to prepare a reaction solution. 21g of potassium carbonate was added thereto, and the mixture was stirred while being heated to 110℃using a heating pack. After stirring for 3 hours, the reaction was added dropwise to a beaker containing 1000mL of methanol, and the resultant precipitate was filtered by suction filtration. The collected precipitate was further washed 3 times with 300mL of methanol to obtain 75g of phenoxy resin P-1.
Thereafter, the molecular weight of the phenoxy resin P-1 was measured by using a high performance liquid chromatograph GP8020 manufactured by TOSOH CORPORATION (chromatographic column: hitachi Chemical Company, gelpakGL-A150S and GLA160S manufactured by Ltd., eluent: tetrahydrofuran, flow rate: 1.0 ml/min). As a result, mn= 15769, mw= 38045, and Mw/mn=2.413 were calculated as polystyrene transforms.
Example 1 >
(step (a)) preparation step
[ step (a 1): preparation of matrix ]
A substrate (PET film, thickness: 55 μm) having a plurality of recesses on the surface thereof was prepared. The recess was formed in a conical trapezoid shape having an opening area enlarged toward the front surface side of the base (the center of the bottom portion is the same as the center of the opening portion when viewed from the top surface of the opening portion), the opening diameter was set to 4.3 μm phi, the bottom portion diameter was set to 4.0 μm phi, and the depth was set to 4.0 μm. Further, a plurality of concave portions were regularly formed at intervals of 6.2 μm (center-to-center distances of the respective bottoms) in a three-way arrangement so that 29,000 were formed every 1mm square.
[ step (a 2): configuration of conductive particles
As the component (a), conductive particles (average particle diameter: 3.3 μm, c.v. value of particle diameter: 2.8%, specific gravity: 2.9) in which a nickel layer having a thickness of 0.15 μm was formed on the surface of a core (particle) composed of a plastic (crosslinked polystyrene) were prepared, and the particles were arranged on the surface of the substrate on which the concave portion was formed. Then, the surface of the substrate on which the concave portion is formed is scraped with a micro-adhesive roller to remove the excessive conductive particles, and the conductive particles are disposed only in the concave portion. The average particle diameter and the c.v. value of the particle diameter of the conductive particles were measured by cutting the 1 st adhesive layer produced through the steps (b) and (c) described below into 10cm×10cm, performing Pt sputtering on the surface on which the conductive particles were disposed, and then subjecting 300 conductive particles to SEM observation.
(step (b)) transfer step
[ step (b 1): preparation of composition layer ]
The component (B1), the component (B2), the component (C1), the component (C2), the component (D), the component (E) and the component (F) shown in table 1 were mixed together with an organic solvent (2-butanone) in the blending amounts (unit: parts by mass, solid component amounts) shown in table 1, to obtain a resin solution. Then, the resin solution was applied to a 38 μm thick PET film subjected to silicone release treatment, and hot air drying was performed at 60℃for 3 minutes, whereby a 1.5 μm thick composition layer was produced on the PET film.
TABLE 1
[ step (b 2): transfer of conductive particles
The composition layer formed on the PET film produced in the step (b 1) is placed so as to face the substrate provided with the conductive particles in the recesses produced in the step (a), and the conductive particles are transferred to the composition layer.
(step (c) light irradiation step)
For the composition layer of the transferred conductive particles, a metal halide lamp was used to irradiate a cumulative light amount of 1700mJ/cm from the side of the transferred conductive particles with a UV curing oven (manufactured by Ushio Inc.. Manufactured by UVC-2534/1MNLC3-XJ 01) 2 Ultraviolet rays (wavelength: 365 nm), which activate the component (B2) and polymerize the component (B1). Thus, the photocurable component ((B1) component and (B2) component) in the composition layer is cured, and the 1 st adhesive layer is formed.
(step (d) lamination step)
[ step (d 1): production of the 2 nd adhesive layer
The component (C1), the component (C2), the component (D), the component (E) and the component (F) shown in Table 2 were mixed together with the organic solvent (2-butanone) in the blending amounts (unit: parts by mass, solid component amount) shown in Table 2, to obtain a resin solution. Subsequently, the resin solution was applied to a 50 μm thick PET film subjected to silicone release treatment, and hot air drying was performed at 60℃for 3 minutes, whereby a 2 nd adhesive layer having a thickness of 12.5 μm was produced on the PET film.
TABLE 2
[ step (d 2): lamination of the 2 nd adhesive layer
Bonding the 1 st adhesive layer produced in the step (c) and the 2 nd adhesive layer produced in the step (d 1) while applying a temperature of 50 ℃. Thus, a bilayer structure anisotropic conductive adhesive film (thickness: 14 μm) was obtained.
Example 2 >
An anisotropic conductive adhesive film was produced in the same manner as in example 1, except that the following step (e) was performed in addition to the steps (a) to (d).
(step (e) 2. Th lamination step)
[ step (e 1): production of the 3 rd adhesive layer ]
The component (C1), the component (C2), the component (D), the component (E) and the component (F) shown in Table 3 were mixed together with the organic solvent (2-butanone) in the blending amounts (unit: parts by mass, solid component amount) shown in Table 3, to obtain a resin solution. Subsequently, the resin solution was applied to a 50 μm thick PET film subjected to silicone release treatment, and hot air drying was performed at 60℃for 3 minutes, whereby a 3 rd adhesive layer having a thickness of 2.0 μm was produced on the PET film.
TABLE 3
[ step (e 2): lamination of the 3 rd adhesive layer
The 1 st adhesive layer exposed by peeling the PET film on the 1 st adhesive layer side of the anisotropic conductive adhesive film produced in the step (d 2) was bonded to the 3 rd adhesive layer produced in the step (e 1) while applying a temperature of 50 ℃. Thus, an anisotropic conductive adhesive film (thickness: 16 μm) of a three-layer structure was obtained.
Example 3 to example 10, comparative example 1 >
In the same manner as in example 2 except that the kind and/or blending amount of the blended components were changed as shown in table 4 in the step (b 1), an anisotropic conductive adhesive film having a three-layer structure was produced.
TABLE 4
Example 11 >
In the step (c), the cumulative light amount of the irradiated light was changed to 2000mJ/cm 2 Except for this, in the same manner as in example 10, a catalyst was producedAn anisotropic conductive adhesive film of three-layer structure.
Example 12 >
In the step (c), the cumulative light quantity of the irradiated light was changed to 2300mJ/cm 2 Except for this, in the same manner as in example 10, an anisotropic conductive adhesive film of a three-layer structure was produced.
Example 13 >
In the step (B1), 1.0 parts by mass of Omnirad907 was used as the component (B2) in place of Irgacure OXE-02; changing the cumulative light quantity of the light to 2000mJ/cm 2 Except for this, in the same manner as in example 2, an anisotropic conductive adhesive film of a three-layer structure was produced.
Example 14 >
In the step (b 1) and the step (d 1), as the component (C1), 40 parts by mass of YL983U was used instead of ETERNACOLL OXBP and CELLOXIDE8010; and an anisotropic conductive adhesive film having a double-layer structure was produced in the same manner as in example 1, except that 7 parts by mass of SI-60L was used as the (C2) component in place of CXC-1821.
Example 15 >
In the step (b 1) and the step (D1), 10 parts by mass of HP-4032D as the component (C3) was used in place of the component (C1); and an anisotropic conductive adhesive film having a double-layer structure was produced in the same manner as in example 1, except that 40 parts by mass of HX-3941HP as the (C4) component was used instead of the (C2) component.
Example 16 >
An anisotropic conductive adhesive film having a two-layer structure was produced in the same manner as in example 1, except that the following step (a 2 ') was performed instead of step (a 2), and the substrate obtained in the following step (a 2') was used as the substrate in which the conductive particles were disposed in the recesses used in step (b 2).
[ step (a 2'): solder particle production and arrangement
100g of Sn-Bi solder particles (manufactured by 5N Plus Inc. having a melting point of 138 ℃ C., type 8) were immersed in distilled water, and after ultrasonic dispersion, leveling was performed, whereby solder particles floating in the supernatant liquid were recovered. This operation was repeated, and 10g of solder particles were recovered. The obtained solder particles had an average particle diameter of 1.0 μm and a c.v. value of 42%. Next, the obtained solder particles (average particle diameter: 1.0 μm, C.V. value of particle diameter: 42%) were disposed on the surface of the substrate prepared in step (a 1) on which the recesses were formed. Then, the surface of the substrate on which the concave portion is formed is scraped with a micro-adhesive roller to remove the excessive solder particles, and the solder particles are disposed only in the concave portion. Next, the substrate having the solder particles disposed in the concave portions was put into a hydrogen radical reduction furnace (SHINKO SEIKI co., ltd. Manufactured by ltd.) and then, after vacuum-pumping, hydrogen gas was introduced into the furnace to fill the furnace with hydrogen gas. Thereafter, the temperature in the furnace was adjusted to 120℃and the hydrogen radicals were irradiated for 5 minutes. Thereafter, the hydrogen gas in the furnace was removed by vacuum evacuation, and after heating to 145 ℃, the nitrogen gas was introduced into the furnace to return to atmospheric pressure, and then the temperature in the furnace was lowered to room temperature, whereby solder particles were formed. Thus, a substrate having conductive particles (solder particles) disposed in the recesses is prepared for use in the step (b 2).
In addition, solder particles were produced by the same operation, and the obtained solder particles were recovered from the concave portion by striking the back side of the concave portion of the base. It was confirmed that a part of the surface of the solder particle had a flat surface portion, and the ratio (B/a) of the diameter B of the flat surface portion to the diameter a of the solder particle was 0.15. When a quadrangle circumscribed with the projected image of the solder particles was formed from two pairs of parallel lines, it was confirmed that when the distance between the opposing sides was X and Y (where Y < X), Y/X was 0.93. When the average particle diameter and the c.v. value of the particle diameter of the solder particles were measured, the average particle diameter was 3.8 μm, and the c.v. value of the particle diameter was 7.9%. The average particle diameter of the solder particles and B/A, Y/X were measured by cutting the 1 st adhesive layer produced in the steps (B) and (c) into 10cm×10cm, pt sputtering the surface on which the solder particles were disposed, and SEM observation of 300 solder particles.
Example 17 >
An anisotropic conductive adhesive film having a three-layer structure was produced in the same manner as in example 2, except that the step (a 2') was performed instead of the step (a 2).
Comparative example 2 >
An anisotropic conductive adhesive film having a three-layer structure was produced in the same manner as in example 2, except that the step (c) was not performed.
< evaluation >
(evaluation of transfer Rate of conductive particles)
The anisotropic conductive adhesive films of examples 1 to 17 and comparative examples 1 to 2 were measured at 20 sites with a microscope and image analysis software (ImagePro, hakuto co., ltd.: at 25,000 μm) 2 The average value of the conductive particles is converted into each 1mm 2 The number of conductive particles was divided by the number of recesses formed in the substrate, and the transfer rate of the conductive particles was measured (see the following formula). The conductive particles were evaluated as "S" in the case where the transfer rate of the conductive particles was 95% or more, the conductive particles were evaluated as "a" in the case where the transfer rate of the conductive particles was 90% or more and less than 95%, the conductive particles were evaluated as "B" in the case where the transfer rate of the conductive particles was 80% or more and less than 90%, and the conductive particles were evaluated as "C" in the case where the transfer rate of the conductive particles was less than 80%. The results are shown in tables 5 to 7.
Transfer rate (%) = (average density of conductive particles in anisotropic conductive adhesive film/density of recesses formed on substrate) ×100 of conductive particles
(evaluation of the capturing Rate of conductive particles and evaluation of connection resistance)
[ preparation of Circuit Components ]
As the 1 st circuit component (a), a wiring pattern (pattern width: 19 μm, inter-electrode space: 5 μm) in which AlNd (100 nm)/Mo (50 nm)/ITO (100 nm) was formed on the surface of an alkali-free glass substrate (OA-11,Nippon Electric Glass Co, ltd., external shape: 38 mm. Times.28 mm, thickness: 0.3 mm) was prepared. As the 1 st circuit component (b), a wiring pattern (pattern width: 19 μm, inter-electrode space: 5 μm) of Cr (20 nm)/Au (200 nm) was formed on the surface of an alkali-free glass substrate (manufactured by OA-11,Nippon Electric Glass Co, ltd., external shape: 38 mm. Times.28 mm, thickness: 0.3 mm). As the 2 nd circuit member, IC chips (outer shape: 0.9 mm. Times.20.3 mm, thickness: 0.3mm, bump electrode size: 70. Mu.m.times.12 μm, inter-bump electrode space: 12 μm, bump electrode thickness: 8 μm) were prepared in which bump electrodes were arranged in 2 rows in a staggered manner.
[ production of connection Structure (a) ]
The anisotropic conductive adhesive films of examples 1 to 13 and comparative examples 1 to 2 were used to produce connection structures (a). The anisotropic conductive adhesive film is disposed on the 1 st circuit member (a) so that the 1 st adhesive layer or the 3 rd adhesive layer is in contact with the 1 st circuit member (a). A thermocompression bonding apparatus (BS-17U,OHASHI ENGINEERING Co, manufactured by Ltd.) composed of a stage including a ceramic heater and a tool (8 mm. Times.50 mm) was used at 70℃and 0.98MPa (10 kgf/cm) 2 ) The anisotropic conductive adhesive film was bonded to the 1 st circuit member (a) under heating and pressure for 2 seconds, and the release film on the opposite side of the anisotropic conductive adhesive film from the 1 st circuit member (a) was peeled off. Next, after the bump electrode of the 1 st circuit member (a) and the circuit electrode of the 2 nd circuit member were aligned, the 2 nd adhesive layer of the anisotropic conductive adhesive film was bonded to the 2 nd circuit member at 130 ℃ for 5 seconds under heating/pressing at 40MPa, thereby producing a connection structure (a). The temperature represents the highest measured temperature of the anisotropic conductive adhesive film, and the pressure represents a value calculated for the total area of the surfaces of the bump electrode of the 2 nd circuit member and the 1 st circuit member (a).
[ production of connection Structure (b) ]
The anisotropic conductive adhesive film of example 14 was used as the anisotropic conductive adhesive film; and a connection structure (b) was produced in the same manner as the connection structure (a) except that the connection structure was heated/pressurized at 140℃for 5 seconds under 60 MPa.
[ production of connection Structure (c) ]
The anisotropic conductive adhesive film of example 15 was used as the anisotropic conductive adhesive film; and a connection structure (c) was produced in the same manner as the connection structure (a) except that the connection structure was heated/pressurized at 230℃for 5 seconds under 60 MPa.
[ production of connection Structure (d) ]
The anisotropic conductive adhesive films of examples 16 to 17 were used as the anisotropic conductive adhesive films, respectively; the 1 st circuit part (b) is used instead of the 1 st circuit part (a); and a connection structure (d) was produced in the same manner as the connection structure (a) except that the connection structure was heated/pressurized at 160℃for 5 seconds under 30 MPa.
[ evaluation of the capturing Rate of conductive particles ]
In the production of the connection structures (a) to (d)) using the anisotropic conductive adhesive films of examples 1 to 17 and comparative examples 1 to 2, the capturing rate of the conductive particles between the bump electrode and the circuit electrode was evaluated. The capture ratio of the conductive particles is a ratio of the density of the conductive particles on the bump electrode to the density of the conductive particles in the anisotropic conductive adhesive film, and is calculated according to the following formula. The average number of conductive particles on the bump electrodes was obtained by measuring the number of conductive particles trapped per 1 bump by observing the mounted circuit component from the glass substrate side using a differential interference microscope. The case where the capturing rate of the conductive particles is 90% or more is evaluated as "S" determination, the case where the capturing rate of the conductive particles is 80% or more and less than 90% is evaluated as "a" determination, the case where the capturing rate of the conductive particles is 70% or more and less than 80% is evaluated as "B" determination, and the case where the capturing rate of the conductive particles is less than 70% is evaluated as "C" determination. The results are shown in tables 5 to 7.
Capture ratio (%) = (average of number of conductive particles on bump electrode/(bump electrode area×density of conductive particles in anisotropic conductive adhesive film)) ×100 of conductive particles
[ evaluation of connection resistance ]
Immediately after the production of the connection structure and after the high temperature and high humidity test, the connection resistance at 14 was measured by the four-terminal measurement method, and the connection resistances of examples 1 to 17 and comparative examples 1 to 2 were evaluated using the maximum value of the measured connection resistance values. The high temperature and high humidity test was performed by treating the connection structure in a high temperature and high humidity tank having a temperature of 85 ℃ and a humidity of 85% rh for 500 hours. A digital multimeter (manufactured by MLR21, kusumoto Chemicals, ltd) was used for measuring the connection resistance. The connection resistance value is evaluated as "S" determination, the connection resistance value is 1.0Ω or more and less than 2.5Ω is evaluated as "a" determination, the connection resistance value is 2.5Ω or more and less than 5.0Ω is evaluated as "B" determination, the connection resistance value is 5.0Ω or more and less than 10.0Ω is evaluated as "C" determination, and the connection resistance value is 10.0Ω or more is evaluated as "D" determination. The results are shown in tables 5 to 7.
TABLE 5
TABLE 6
TABLE 7
Symbol description
1-1 st adhesive film, 2-2 nd adhesive layer, 3-adhesive component, 4-conductive particles, 5-3 rd adhesive layer, 6-base, 7-recess, 9-composition layer, 10A, 10B-adhesive film for circuit connection, 21-1 st circuit substrate, 22-1 st electrode (circuit electrode), 23-1 st circuit member, 24-2 nd circuit substrate, 25-2 nd electrode (bump electrode), 26-2 nd circuit member, 27-connection part, 100-connection structure.

Claims (18)

1. A method for manufacturing an adhesive film for circuit connection, comprising the steps of:
preparing a substrate having a plurality of recesses on a surface thereof and conductive particles disposed in at least a part of the plurality of recesses;
transferring the conductive particles to a composition layer containing a photocurable component and a 1 st thermosetting component by providing the composition layer on the surface of the substrate;
forming a 1 st adhesive layer containing a plurality of the conductive particles, a cured product of the photocurable component, and the 1 st thermosetting component by irradiating the composition layer with light; a kind of electronic device with high-pressure air-conditioning system
A2 nd adhesive layer containing a 2 nd thermosetting component is provided on one face of the 1 st adhesive layer.
2. The method for producing an adhesive film for circuit connection according to claim 1, wherein,
The photocurable component comprises a radical polymerizable compound and a radical photopolymerization initiator,
the 1 st thermosetting component comprises a cationically polymerizable compound and a thermal cationic polymerization initiator.
3. The method for producing an adhesive film for circuit connection according to claim 2, wherein,
the 1 st thermosetting component contains a compound having a cyclic ether group as the cationically polymerizable compound.
4. The method for producing an adhesive film for circuit connection according to claim 3, wherein,
the 1 st thermosetting component contains at least 1 selected from the group consisting of oxetane compounds and alicyclic epoxy compounds as the cationically polymerizable compound.
5. The method for producing an adhesive film for circuit connection according to any one of claims 2 to 4, wherein,
the photocurable component contains a compound represented by the following formula (1) as the radical polymerizable compound,
in the formula (1), R 1 Represents a hydrogen atom or a methyl group, and X represents an alkanediyl group having 1 to 3 carbon atoms.
6. The method for producing an adhesive film for circuit connection according to any one of claims 2 to 5, wherein,
the photocurable component contains a compound represented by the following formula (I) as the photo radical polymerization initiator,
In the formula (I), R 2 、R 3 R is R 4 Each independently represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an organic group containing an aromatic hydrocarbon group.
7. The method for producing an adhesive film for circuit connection according to any one of claims 2 to 6, wherein,
the 1 st thermosetting component contains a salt compound having a cation represented by the following formula (II) or the following formula (III) as the thermal cationic polymerization initiator,
in the formula (II), R 5 R is R 6 Each independently represents 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 7 Representing the carbon numberAn alkyl group of 1 to 6,
in the formula (III), R 8 R is R 9 Each independently represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an organic group containing a substituted or unsubstituted aromatic hydrocarbon group, R 10 R is R 11 Each independently represents an alkyl group having 1 to 6 carbon atoms.
8. The method for producing an adhesive film for circuit connection according to any one of claims 1 to 7, wherein,
the conductive particles have an average particle diameter of 1 to 30 μm,
the conductive particles have a particle diameter C.V. value of 20% or less.
9. The method for producing an adhesive film for circuit connection according to any one of claims 1 to 8, wherein,
The conductive particles are solder particles.
10. The method for producing an adhesive film for circuit connection according to claim 9, wherein,
the solder particles include at least one selected from the group consisting of tin, tin alloy, indium, and indium alloy.
11. The method for producing an adhesive film for circuit connection according to claim 10, wherein,
the solder particles include at least one selected from the group consisting of an In-Bi alloy, an In-Sn-Ag alloy, an Sn-Au alloy, an Sn-Bi-Ag alloy, an Sn-Ag-Cu alloy, and an Sn-Cu alloy.
12. The method for producing an adhesive film for circuit connection according to any one of claims 9 to 11, wherein,
a part of the surface of the solder particles has a planar portion.
13. The method for producing an adhesive film for circuit connection according to claim 12, wherein,
the ratio B/A of the diameter B of the flat surface portion to the diameter A of the solder particle satisfies the following formula,
0.01＜B/A＜1.0。
14. the method for producing an adhesive film for circuit connection according to any one of claims 1 to 13, wherein,
in the case of forming a quadrangle circumscribed with the projected image of the conductive particles from two pairs of parallel lines, when the distance between the opposing sides is X and Y, and Y < X, X and Y satisfy the following formula,
0.8＜Y/X≤1.0。
15. The method for producing an adhesive film for circuit connection according to any one of claims 1 to 14, wherein,
the plurality of recesses are formed in a predetermined pattern.
16. An adhesive film for circuit connection containing conductive particles, comprising:
a 1 st adhesive layer containing a plurality of the conductive particles, a cured product of a photocurable component, and a 1 st thermosetting component; and a 2 nd adhesive layer disposed on the 1 st adhesive layer and containing a 2 nd thermosetting component,
at least a part of the plurality of conductive particles are arranged in a predetermined pattern when the circuit connection adhesive film is viewed in plan, and are arranged laterally in a state in which adjacent conductive particles are separated from each other in a longitudinal section of the circuit connection adhesive film.
17. A connection structure is provided with:
a 1 st circuit part having a 1 st electrode;
a 2 nd circuit part having a 2 nd electrode; a kind of electronic device with high-pressure air-conditioning system
A connecting portion comprising the cured body of the adhesive film for circuit connection according to claim 16, electrically connecting the 1 st electrode and the 2 nd electrode to each other via the conductive particles, and bonding the 1 st circuit member and the 2 nd circuit member.
18. A method of manufacturing a connection structure, comprising the steps of:
disposing the adhesive film for circuit connection according to claim 16 between a surface of a 1 st circuit member having a 1 st electrode provided with the 1 st electrode and a surface of a 2 nd circuit member having a 2 nd electrode provided with the 2 nd electrode; a kind of electronic device with high-pressure air-conditioning system
And heating a laminate including the 1 st circuit member, the adhesive film for circuit connection, and the 2 nd circuit member in a state of being pressed in a thickness direction of the laminate, thereby electrically connecting the 1 st electrode and the 2 nd electrode to each other via the conductive particles and bonding the 1 st circuit member and the 2 nd circuit member.
CN202180089778.2A 2020-11-12 2021-11-10 Adhesive film for circuit connection, method for producing same, connection structure, and method for producing same Pending CN116685652A (en)

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