Adhesive film for circuit connection, adhesive composition for circuit connection, circuit connection structure, and method for manufacturing the same

Abstract

The adhesive film for circuit connection contains conductive particles and includes a region A containing a cationic polymerizable compound, a thermal cationic polymerization initiator, and an ion scavenger in the thickness direction of the film. The cationic polymerizable compound contains an epoxy compound, the thermal cationic polymerization initiator contains an anilinium salt, and the ion scavenger contains at least one metal compound selected from the group consisting of aluminum hydroxide, aluminum oxide, magnesium hydroxide, magnesium oxide, zirconium hydroxide, zirconium oxide, bismuth hydroxide, bismuth oxide, calcium hydroxide, calcium oxide, tin hydroxide, tin oxide, manganese hydroxide, manganese oxide, antimony hydroxide, antimony oxide, silicon hydroxide, silicon oxide, titanium hydroxide, and titanium oxide.

Description

Technical Field

[0001] The present invention relates to an adhesive film for circuit connection, an adhesive composition for circuit connection, a circuit connection structure, and a method for manufacturing the same. Background Art

[0002] In recent years, in the display industry, in the module of a display unit, a mode shift has occurred from a liquid crystal display to an organic LED (Light Emitting Diode), and accordingly, the constituent materials of the panel have changed.

[0003] In an existing liquid crystal display, a glass substrate is used as a substrate, and as a circuit material formed on the glass substrate, metals such as aluminum are used in the circuit of the base layer, and ITO (Indium Tin Oxide) etc. are used in the electrodes of the surface layer. On the other hand, in an organic LED, a flexible plastic substrate such as a polyimide substrate is used as a substrate, and Ti is mainly used as a circuit material formed on the plastic substrate. And, in order to impart flexibility, a pressure-sensitive adhesive layer and a flexible member such as a polyethylene terephthalate (PET) substrate are usually disposed on the lower surface of the polyimide substrate (for example, refer to Patent Document 1).

[0004] In a liquid crystal display, from the viewpoints of fine pitch, light weight and thinness, etc., a so-called COG (chip on glass) packaging in which various electronic parts such as a driving IC are directly packaged on the glass substrate of the panel is adopted. And, as a COG packaging method, for example, the following method is used: An anisotropic conductive adhesive film for circuit connection in which conductive particles are dispersed in an adhesive is used to thermocompression-bond a liquid crystal driving IC to a glass substrate, thereby obtaining a circuit connection structure.

[0005] Prior Art Documents

[0006] Patent Documents

[0007] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2016-054288 Summary of the Invention

[0008] Technical Problem to be Solved by the Invention

[0009] In organic light-emitting diodes (OLEDs), chip-on-plastic (COP) packaging, in which driving ICs and the like are directly packaged on a plastic substrate, is also being adopted. However, if excessive pressure is applied to the plastic substrate, problems such as deformation, cracking, and disconnection of the Ti circuit provided on the polyimide substrate may occur as defects accompanying the deformation of the plastic substrate. Therefore, in the COG packaging using an adhesive film for circuit connection, the pressure converted to the area of the bump electrodes of the IC chip is usually 50 to 100 MPa, but in the COP packaging of organic LEDs, in order to prevent disconnection of the circuit, packaging using a low pressure of, for example, 40 MPa or less is preferred. In the package manufactured under such low-pressure conditions, the connection resistance between the opposing electrodes tends to be high, and it is difficult to obtain sufficient conduction characteristics.

[0010] On the other hand, the high density of bumps in the IC chip is developing, and high insulation is required to be ensured between adjacent circuits. However, through the research by the inventors, it has been found that in a package manufactured using an adhesive film for circuit connection containing conductive particles, for example, when the curing system of the adhesive is a cation-epoxy curing system or the like, the insulation resistance between adjacent circuits tends to decrease after a high-temperature and high-humidity test.

[0011] The main object of the present invention is to provide an adhesive film for circuit connection that can sufficiently ensure conduction between opposing electrodes of a circuit connection structure even when circuit components are connected at a low pressure and can sufficiently maintain insulation between adjacent circuits.

[0012] Means for Solving the Technical Problem

[0013] To solve the above problems, an aspect of the present invention provides an adhesive film for circuit connection containing conductive particles. In the thickness direction of the film, the adhesive film includes a region A containing a cationic polymerizable compound, a thermal cationic polymerization initiator, and an ion scavenger. The cationic polymerizable compound includes a compound having one or more ring-opening polymerizable cyclic ether groups in the molecule. The thermal cationic polymerization initiator includes anilinium salt. The ion scavenger includes at least one metal compound selected from the group consisting of aluminum hydroxide, aluminum oxide, magnesium hydroxide, magnesium oxide, zirconium hydroxide, zirconium oxide, bismuth hydroxide, bismuth oxide, calcium hydroxide, calcium oxide, tin hydroxide, tin oxide, manganese hydroxide, manganese oxide, antimony hydroxide, antimony oxide, silicon hydroxide, silicon oxide, titanium hydroxide, and titanium oxide.

[0014] According to the adhesive film for circuit connection, even when circuit components are connected to each other at a low voltage, conduction between the opposing electrodes of the circuit connection structure can be sufficiently ensured, and insulation between adjacent circuits can be sufficiently maintained. The reason for obtaining such an effect is not necessarily clear, but the present inventors presume as follows. It is considered that the adhesive film for circuit connection according to the present invention has a cationic polymerization system region (including a compound having one or more ring-opening polymerizable cyclic ether groups in the molecule), and can obtain an exclusivity that easily excludes the adhesive component between the opposing electrodes and near the conductive particles. Moreover, by combining with the above-mentioned specific thermal cationic polymerization initiator, compared with other thermal cationic polymerization initiators such as sulfonium salts, it can exhibit curing characteristics with excellent curing inhibition resistance, and by suppressing the flow of conductive particles between the opposing electrodes, conduction characteristics can be sufficiently ensured. Further, it is considered that by having region A containing the above-mentioned specific ion scavenger in the adhesive film for circuit connection, even when chloride ions or the like that deteriorate the insulation are generated from conductive particles or the like in the circuit connection structure, the ions can be captured, and insulation between adjacent circuits can be sufficiently maintained.

[0015] The conductive particles may have palladium plating. The adhesive film for circuit connection containing such conductive particles is likely to exhibit a low resistance to a circuit having a Ti surface.

[0016] From the viewpoint of the pot life, the anilinium salt may be an anilinium salt having an anion containing boron as a constituent element.

[0017] The conductive particles may be concentrated on one side of the film. At this time, it is easy to improve the capture efficiency of the conductive particles during circuit connection.

[0018] Region A may include region P which is a cured product further containing a photocurable resin component in the thickness direction of the film, and conductive particles are dispersed in region P. At this time, the flow of the conductive particles during circuit connection can be suppressed, the bridging of the flowed conductive particles between adjacent circuits to deteriorate the insulation can be prevented, and the capture efficiency of the conductive particles can be further improved.

[0019] Another aspect of the present invention provides an adhesive film for circuit connection, which includes: a first adhesive layer containing conductive particles, a cured product of a photocurable resin component, and a first thermosetting resin component; and a second adhesive layer provided on the first adhesive layer and containing a second thermosetting resin component. In this adhesive film for circuit connection, one or both of the first adhesive layer and the second adhesive layer further contain an ion scavenger, and one or both of the first thermosetting resin component and the second thermosetting resin component contain a cationically polymerizable compound and a thermal cationic polymerization initiator. The cationically polymerizable compound includes a compound having one or more ring-opening polymerizable cyclic ether groups in the molecule, the thermal cationic polymerization initiator includes an anilinium salt, and the ion scavenger includes at least one metal compound selected from the group consisting of aluminum hydroxide, alumina, magnesium hydroxide, magnesia, zirconium hydroxide, zirconia, bismuth hydroxide, bismuth oxide, calcium hydroxide, calcium oxide, tin hydroxide, tin oxide, manganese hydroxide, manganese oxide, antimony hydroxide, antimony oxide, silicon hydroxide, silica, titanium hydroxide, and titanium oxide.

[0020] According to this adhesive film for circuit connection, even when circuit components are connected to each other at a low voltage, conduction between the opposing electrodes of the circuit connection structure can be sufficiently ensured, and insulation between adjacent circuits can be sufficiently maintained. In addition, since the first adhesive layer containing conductive particles contains a cured product of a photocurable resin component, the flow of conductive particles during circuit connection can be suppressed, the conductive particles that flow can be prevented from bridging between adjacent circuits to deteriorate the insulation, and the capture efficiency of the conductive particles can be further improved.

[0021] The conductive particles may have palladium plating. The adhesive film for circuit connection containing such conductive particles is likely to exhibit low resistance to a circuit having a Ti surface.

[0022] From the viewpoint of pot life, the anilinium salt may be an anilinium salt having an anion containing boron as a constituent element.

[0023] Another aspect of the present invention provides an adhesive composition for circuit connection, which contains a cationically polymerizable compound, a thermal cationic polymerization initiator, and an ion scavenger. In this adhesive composition for circuit connection, the cationically polymerizable compound includes a compound having one or more ring-opening polymerizable cyclic ether groups in the molecule, the thermal cationic polymerization initiator includes an anilinium salt, and the ion scavenger includes at least one metal compound selected from the group consisting of aluminum hydroxide, alumina, magnesium hydroxide, magnesia, zirconium hydroxide, zirconia, bismuth hydroxide, bismuth oxide, calcium hydroxide, calcium oxide, tin hydroxide, tin oxide, manganese hydroxide, manganese oxide, antimony hydroxide, antimony oxide, silicon hydroxide, silica, titanium hydroxide, and titanium oxide.

[0024] According to the adhesive composition for circuit connection, the region A or the first adhesive layer and / or the second adhesive layer in the above-described adhesive film for circuit connection can be formed.

[0025] From the viewpoint of the pot life, the anilinium salt can be an anilinium salt having an anion containing boron as a constituent element.

[0026] The adhesive composition for circuit connection can further contain conductive particles and can further contain a photocurable resin component. Such an adhesive composition for circuit connection can form the region P or the first adhesive layer in the above-described adhesive film for circuit connection.

[0027] The conductive particles can have palladium plating.

[0028] Another aspect of the present invention provides a method for manufacturing a circuit connection structure, which includes the following steps: interposing the above-described adhesive film for circuit connection between a first circuit component having a first electrode and a second circuit component having a second electrode, and performing thermocompression bonding on the first circuit component and the second circuit component to electrically connect the first electrode and the second electrode to each other.

[0029] One of the first circuit component and the second circuit component can be an IC chip, and the other can be a plastic substrate having an electrode containing Ti.

[0030] Another aspect of the present invention provides a circuit connection structure, which includes: a first circuit component having a first electrode; a second circuit component having a second electrode; and a circuit connection portion disposed between the first circuit component and the second circuit component to electrically connect the first electrode and the second electrode to each other, wherein the circuit connection portion includes a cured product of the above-described adhesive film for circuit connection.

[0031] One of the first circuit component and the second circuit component can be an IC chip, and the other can be a plastic substrate having an electrode containing Ti.

[0032] Advantages of the Invention

[0033] According to the present invention, it is possible to provide an adhesive film for circuit connection that can sufficiently ensure conduction between opposing electrodes of a circuit connection structure even when circuit components are connected to each other at a low voltage and can sufficiently maintain insulation between adjacent circuits. Such an adhesive film for circuit connection can be applied to COP packaging. Further, according to the present invention, it is possible to provide an adhesive composition for circuit connection suitable for forming such an adhesive film for circuit connection. In addition, according to the present invention, it is possible to provide a circuit connection structure using the above-described adhesive film for circuit connection and a manufacturing method thereof. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a schematic cross-sectional view showing an embodiment of an adhesive film for circuit connection.

[0035] Figure 2 It is a schematic cross-sectional view showing an embodiment of a circuit connection structure.

[0036] Figure 3 It is a schematic cross-sectional view showing an embodiment of a manufacturing method of a circuit connection structure. Figure 3 (a) and Figure 3 (b) are schematic cross-sectional views showing each process. Detailed Embodiment

[0037] Hereinafter, with reference to the accompanying drawings, embodiments of the present invention will be described in detail. In the following description, the same or corresponding parts are denoted by the same reference numerals, and repeated descriptions are omitted. In addition, the present invention is not limited to the following embodiments. In this specification, (meth)acryloyl means acryloyl or methacryloyl, and the same applies to other similar expressions such as (meth)acrylate. Within the numerical ranges described in this specification, the upper limit value or the lower limit value of the numerical range can be replaced with the values shown in the examples. Also, the lower limit value and the upper limit value of the numerical range can be arbitrarily combined with the lower limit value or the upper limit value of other numerical ranges. In the notation of the numerical range "A to B", the numerical values A and B at both ends are included in the numerical range as the lower limit value and the upper limit value, respectively. In this specification, for example, the description "10 or more" means 10 and values exceeding 10, and the same applies in the case of different numerical values. Also, for example, the description "10 or less" means 10 and values less than 10, and the same applies in the case of different numerical values. Also, each component and material exemplified in this specification can be used alone or in combination of two or more as long as there is no particular description. In this specification, when there are multiple substances corresponding to each component in the composition, unless otherwise specified, the content of each component in the composition refers to the total amount of the multiple substances present in the composition.

[0038] [Adhesive Film for Circuit Connection]

[0039] The adhesive film for circuit connection of this embodiment contains conductive particles, and includes a region A containing a cationic polymerizable compound, a thermal cationic polymerization initiator, and an ion scavenger in the thickness direction of the film. The conductive particles may be biased to one side of the film, and the region A may include a region P containing a cured product of a photocurable resin component further in the thickness direction of the film, and conductive particles are dispersed in the region P. And the region A may include a region S containing a cationic polymerizable compound, a thermal cationic polymerization initiator, and an ion scavenger in the thickness direction of the film, and not containing a cured product of a photocurable resin component.

[0040] Figure 1 is a schematic cross-sectional view showing an embodiment of the adhesive film for circuit connection according to the present embodiment. Figure 1 The adhesive film 10 for circuit connection shown in Figure 1 (hereinafter, sometimes simply referred to as "adhesive film 10".) includes: a first adhesive layer 1 containing conductive particles 4, and an adhesive component 5 containing a cured product of a photocurable resin component and a (first) thermosetting resin component; and a second adhesive layer 2 provided on the first adhesive layer 1 and containing a (second) thermosetting resin component.

[0041] Hereinafter, with reference to Figure 1 the adhesive film for circuit connection of the present embodiment will be described.

[0042] In the adhesive film 10, the conductive particles 4 are dispersed in the first adhesive layer 1. Therefore, the adhesive film 10 can be an adhesive film for circuit connection having anisotropic conductivity (anisotropic conductive adhesive film). The adhesive film 10 can be interposed between a first circuit component having a first electrode and a second circuit component having a second electrode, and is used for thermocompression bonding the first circuit component and the second circuit component to electrically connect the first electrode and the second electrode to each other.

[0043] <First Adhesive Layer>

[0044] The first adhesive layer 1 contains conductive particles 4 (hereinafter, sometimes referred to as "(A) component".), a cured product of a photocurable resin component (hereinafter, sometimes referred to as "(B) component".), and a thermosetting resin component (hereinafter, sometimes referred to as "(C) component".). The first adhesive layer 1 can be obtained, for example, by irradiating a composition layer formed from a composition containing (A) component, (B) component, and (C) component with light energy to polymerize the components contained in (B) component and cure (B) component. The first adhesive layer 1 contains (A) component, and an adhesive component 5 containing a cured product of (B) component and (C) component. The cured product of (B) component can be a cured product obtained by completely curing (B) component, or a cured product obtained by partially curing (B) component. (C) component is a component that can flow during circuit connection, and is, for example, an uncured curable resin component.

[0045] (A) Component: Conductive Particles

[0046] Regarding the component (A), as long as it is a particle having conductivity, there is no particular limitation, and it can be metal particles composed of metals such as Au, Ag, Pd, Ni, Cu, solder, etc., conductive carbon particles composed of conductive carbon, etc. The component (A) can be a coated conductive particle having a core (including non-conductive glass, ceramics, plastics (such as polystyrene), etc.) and a coating layer (including the above-mentioned metal or conductive carbon and coating the core). Among them, the component (A) is preferably a coated conductive particle having a core (including metal particles or plastics formed by a heat-fusible metal) and a coating layer (including a metal or conductive carbon and coating the core). Such a coated conductive particle can easily deform the cured product of the thermosetting resin component by heating or pressurization. Therefore, when electrically connecting electrodes to each other, the contact area between the electrode and the component (A) can be increased, and the conductivity between the electrodes can be further improved.

[0047] In terms of the view that it is easy to exhibit low resistance to a circuit having a Ti surface, conductive particles capable of using conductive particles having a palladium plating can be used. At this time, a palladium plating can be provided on the outermost surface of the conductive particles. Specifically, conductive particles obtained by subjecting the surface of a plastic core body to a Ni plating and then subjecting the outermost surface to a replacement plating with Pd can be used. In terms of the view of preventing short circuits between conductive particles, conductive particles having insulating fine particles supported on the surface of such conductive particles can be used. In terms of the view that it is easy to further exhibit low resistance to a circuit having a Ti surface, during the Ni plating process, a ceramic core material of 100 nm to 200 nm can be incorporated into the plating, and then Pd plating can be performed, and insulating fine particles can be supported thereon as needed.

[0048] (A) component can be an insulating coated conductive particle having the above-mentioned metal particles, conductive carbon particles or coated conductive particles and an insulating layer containing an insulating material such as resin and coating the surface of the particle. If the (A) component is an insulating coated conductive particle, even when the content of the (A) component is large, since an insulating layer is provided on the surface of the particle, the occurrence of a short circuit caused by the contact between the (A) components can be suppressed, and the insulation between adjacent electrode circuits can also be improved. The (A) component can be used alone one of the above various conductive particles or a combination of two or more kinds.

[0049] (A) The maximum particle size of the component needs to be smaller than the minimum interval of the electrodes (the shortest distance between adjacent electrodes). From the viewpoints of excellent dispersibility and conductivity, the maximum particle size of the (A) component can be 1.0 μm or more, 2.0 μm or more, or 2.5 μm or more. From the viewpoints of excellent dispersibility and conductivity, the maximum particle size of the (A) component can be 20 μm or less, 10 μm or less, or 5 μm or less. In this specification, for any 300 (pcs) conductive particles, the particle size is measured by observation using a scanning electron microscope (SEM), and the obtained maximum value is taken as the maximum particle size of the (A) component. In addition, in the case where the (A) component has protrusions, etc., and the (A) component is not spherical, the particle size of the (A) component is the diameter of the circle circumscribing the conductive particle in the SEM image.

[0050] From the viewpoints of excellent dispersibility and conductivity, the average particle size of the (A) component can be 1.0 μm or more, 2.0 μm or more, or 2.5 μm or more. From the viewpoints of excellent dispersibility and conductivity, the average particle size of the (A) component can be 20 μm or less, 10 μm or less, or 5 μm or less. In this specification, for any 300 (pcs) conductive particles, the particle size is measured by observation using a scanning electron microscope (SEM), and the average value of the obtained particle sizes is taken as the average particle size.

[0051] In the first adhesive layer 1, the (A) component is preferably uniformly dispersed. From the viewpoint of obtaining a stable connection resistance, the particle density of the (A) component in the adhesive film 10 can be 100 particles / mm 2 or more, 1000 particles / mm 2 or more, 3000 particles / mm 2 or more, or 5000 particles / mm 2 or more. From the viewpoint of improving the insulation between adjacent electrodes, the particle density of the (A) component in the adhesive film 10 can be 100000 particles / mm 2 or less, 70000 particles / mm 2 or less, 50000 particles / mm 2 or less, or 30000 particles / mm 2 or less.

[0052] From the viewpoint of being able to further improve conductivity, based on the total mass of the first adhesive layer

[0053] The content of the component (A) may be 1% by mass or more, 5% by mass or more, or 10% by mass or more. From the viewpoint of easily suppressing short circuits, based on the total mass of the first adhesive layer, the content of the component (A) may be 60% by mass or less, 50% by mass or less, or 40% by mass or less. If the content of the component (A) is within the above range, the effects of the present invention tend to be significantly exhibited. In addition, the content of the component (A) in the composition or the composition layer (based on the total mass of the composition or the composition layer) may be the same as the above range.

[0054] Component (B): A photocurable resin component

[0055] Regarding the component (B), as long as it is a resin component that is cured by light irradiation, there is no particular limitation. However, from the viewpoint of more excellent connection resistance, it may be a resin component having radical curability. The component (B) may include, for example, a radically polymerizable compound (hereinafter, sometimes referred to as “component (B1)”) and a photo radical polymerization initiator (hereinafter, sometimes referred to as “component (B2)”). The component (C) may be a component composed of the component (C1) and the component (C2).

[0056] Component (B1): A radically polymerizable compound

[0057] The component (B1) is a compound that is radically polymerized by the radicals generated from the component (B2) by irradiating light (for example, ultraviolet light). The component (B1) may be either a monomer or a polymer (or oligomer) formed by polymerizing one or more monomers. The component (B1) may be used alone or in combination of multiple kinds.

[0058] The component (B1) is a compound having a radical polymerizable group that reacts by radicals. As the radical polymerizable group, for example, (meth)acryloyl group, vinyl group, allyl group, styryl group, alkenyl group, alkenylene group, maleimide group, etc. may be cited. From the viewpoint of easily obtaining the desired melt viscosity after polymerization, further improving the effect of reducing the connection resistance, and more excellent connection reliability, the number of radical polymerizable groups (functional group numbers) possessed by the component (B1) may be 2 or more, and from the viewpoint of suppressing the curing shrinkage during polymerization, it may be 10 or less. And, in order to maintain the balance between the crosslinking density and the curing shrinkage, in addition to the compounds having the number of radical polymerizable groups within the above range, compounds having the number of radical polymerizable groups outside the above range may also be used.

[0059] In terms of the view of suppressing the flow of conductive particles, for example, the component (B1) may include a polyfunctional (having two or more functional groups) (meth)acrylate. The polyfunctional (having two or more functional groups) (meth)acrylate may be a bifunctional (meth)acrylate, and the bifunctional (meth)acrylate may be a bifunctional aromatic (meth)acrylate.

[0060] As polyfunctional (meth)acrylates, for example, there may be mentioned aliphatic (meth)acrylates such as 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, neopentyl glycol di(meth)acrylate, 3-methyl-1,5-pentanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 2-butyl-2-ethyl-1,3-propanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, glycerol di(meth)acrylate, tricyclodecane dimethanol (meth)acrylate, ethoxylated 2-methyl-1,3-propanediol di(meth)acrylate; aromatic (meth)acrylates such as ethoxylated bisphenol A type di(meth)acrylate, propoxylated bisphenol A type di(meth)acrylate, ethoxylated propoxylated bisphenol A type di(meth)acrylate, ethoxylated bisphenol F type di(meth)acrylate, propoxylated bisphenol F type di(meth)acrylate, ethoxylated propoxylated bisphenol F type di(meth)acrylate, ethoxylated fluorene type di(meth)acrylate, propoxylated fluorene type di(meth)acrylate, ethoxylated propoxylated fluorene type di(meth)acrylate, trimethylolpropane tri(meth)acrylate, 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 tetraacrylate, dipentaerythritol hexa(meth)acrylate and other aliphatic (meth)acrylates; aromatic epoxy (meth)acrylates such as bisphenol type epoxy (meth)acrylate, novolac type epoxy (meth)acrylate, cresol novolac type epoxy (meth)acrylate, etc.

[0061] In terms of achieving both a reduction effect on the connection resistance and suppressing the flow of particles, based on the total mass of the component (B1), the content of a polyfunctional (two or more functional groups) (meth)acrylate may be, for example, 40 to 100% by mass, 50 to 100% by mass, or 60 to 100% by mass.

[0062] In addition to the polyfunctional (two or more functional groups) (meth)acrylate, the component (B1) may further contain a monofunctional (meth)acrylate. Examples of the monofunctional (meth)acrylate include (meth)acrylic acid; (meth)acrylic acid methyl ester, (meth)acrylic acid ethyl ester, (meth)acrylic acid butyl ester, (meth)acrylic acid isobutyl ester, (meth)acrylic acid tert-butyl ester, (meth)acrylic acid butoxyethyl ester, (meth)acrylic acid isoamyl ester, (meth)acrylic acid hexyl ester, (meth)acrylic acid 2-ethylhexyl ester, (meth)acrylic acid heptyl ester, (meth)acrylic acid octylheptyl ester, (meth)acrylic acid nonyl ester, (meth)acrylic acid decyl ester, (meth)acrylic acid 2-hydroxyethyl ester, (meth)acrylic acid 2-hydroxypropyl ester, 3-chloro-2-hydroxypropyl (meth)acrylate, (meth)acrylic acid 2-hydroxybutyl ester, methoxypolyethylene glycol (meth)acrylate, ethoxypolyethylene glycol (meth)acrylate, methoxypolypropylene glycol (meth)acrylate, ethoxypolypropylene glycol (meth)acrylate, mono(2-(meth)acryloyloxyethyl) succinate and other aliphatic (meth)acrylates; (meth)acrylic acid benzyl ester, (meth)acrylic acid phenyl ester, (meth)acrylic acid o-biphenyl ester, (meth)acrylic acid 1-naphthyl ester, (meth)acrylic acid 2-naphthyl ester, (meth)acrylic acid phenoxyethyl ester, p-cumylphenoxyethyl (meth)acrylate, o-phenylphenoxyethyl (meth)acrylate, 1-naphthyloxyethyl (meth)acrylate, 2-naphthyloxyethyl (meth)acrylate, phenoxypolyethylene glycol (meth)acrylate, nonylphenoxypolyethylene glycol (meth)acrylate, phenoxypolypropylene glycol (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, 2-hydroxy-3-(o-phenylphenoxy)propyl (meth)acrylate, 2-hydroxy-3-(1-naphthyloxy)propyl (meth)acrylate, 2-hydroxy-3-(2-naphthyloxy)propyl (meth)acrylate and other aromatic (meth)acrylates; (meth)acrylic acid glycidyl ester and other (meth)acrylates having an epoxy group, 3,4-epoxycyclohexylmethyl (meth)acrylate and other (meth)acrylates having an alicyclic epoxy group, (3-ethyloxetane-3-yl)methyl (meth)acrylate and other (meth)acrylates having an oxetanyl group, etc.

[0063] Based on the total mass of the component (B1), the content of the monofunctional (meth)acrylate may be, for example, 0 to 60% by mass, 0 to 50% by mass, or 0 to 40% by mass.

[0064] The cured product of the component (B) can, for example, have a polymerizable group that reacts other than by free radicals. The polymerizable group that reacts other than by free radicals can, for example, be a cationic polymerizable group that reacts by cations. Examples of the cationic polymerizable group include epoxy groups such as glycidyl groups, alicyclic epoxy groups such as epoxycyclohexylmethyl groups, and oxetanyl groups such as ethyloxetanylmethyl groups. The cured product of the component (B) having a polymerizable group that reacts other than by free radicals can be introduced, for example, by using a (meth)acrylate having an epoxy group, a (meth)acrylate having an alicyclic epoxy group, a (meth)acrylate having an oxetanyl group, etc., which are (meth)acrylates having a polymerizable group that reacts other than by free radicals, as the component (B). From the viewpoint of improving reliability, the mass ratio of the (meth)acrylate having a polymerizable group that reacts other than by free radicals to the total mass of the component (B1) (mass (loading amount) of the (meth)acrylate having a polymerizable group that reacts other than by free radicals / total mass (loading amount) of the component (B1)) can be, for example, 0 to 0.7, 0 to 0.5, or 0 to 0.3.

[0065] In addition to polyfunctional (bifunctional or higher) and monofunctional (meth)acrylates, the component (B1) can also contain other free-radical polymerizable compounds. Examples of the other free-radical polymerizable compounds include maleimide compounds, vinyl ether compounds, allyl compounds, styrene derivatives, acrylamide derivatives, nadimide derivatives, etc. Based on the total mass of the component (B1), the content of the other free-radical polymerizable compounds can be, for example, 0 to 40% by mass.

[0066] Component (B2): Photo radical polymerization initiator

[0067] The component (B2) is a photo polymerization initiator that generates free radicals by irradiating light having a wavelength in the range of 150 to 750 nm, preferably in the range of 254 to 405 nm, and more preferably having a wavelength of 365 nm (for example, ultraviolet light). The component (B2) can be used alone or in combination of multiple kinds.

[0068] (B2) component decomposes by light and generates free radicals. That is, the (B2) component is a compound that generates free radicals by applying light energy from the outside. The (B2) component can be a compound having a structure such as an oxime ester structure, a bisimidazole structure, an acridine structure, an α-aminoalkylbenzophenone structure, an aminobenzophenone structure, an N-phenylglycine structure, an acylphosphine oxide structure, a benzyldimethyl ketal structure, an α-hydroxyalkylbenzophenone structure, etc. The (B2) component can be used alone or in combination of multiple kinds. From the viewpoints of easily obtaining the desired melt viscosity and more excellent reduction effect of the connection resistance, the (B2) component can be a compound having at least one structure selected from the group consisting of an oxime ester structure, an α-aminoalkylbenzophenone structure, and an acylphosphine oxide structure.

[0069] 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-methoxycarbonyl)oxime, 1-phenyl-1,2-propanedione-2-(o-ethoxycarbonyl)oxime, 1-phenyl-1,2-propanedione-2-o-benzoyl oxime, 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), acetone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-, 1-(o-acetyl oxime), etc.

[0070] Specific examples of the compound having an α-aminoalkylbenzophenone structure include 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1-(morpholinophenyl)-butan-1-one, etc.

[0071] Specific examples of the compound having an acylphosphine oxide structure include bis(2,6-dimethoxybenzoyl)-2,4,4-trimethyl-pentylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, etc.

[0072] From the viewpoint of suppressing the flow of conductive particles, the content of the (B2) component can 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 (B1) component.

[0073] From the viewpoint of suppressing the flow of conductive particles, based on the total mass of the first adhesive layer, the content of the cured product of the (B) component can be 1% by mass or more, 5% by mass or more, or 10% by mass or more. From the viewpoint of showing low resistance in low-pressure encapsulation, based on the total mass of the first adhesive layer,

[0074] The content of the cured product of component (B) may be 50% by mass or less, 40% by mass or less, or 30% by mass or less. If the content of the cured product of component (B) is within the above range, the effects of the present invention tend to be significantly exhibited. In addition, the content of component (B) in the composition or the composition layer (based on the total mass of the composition or the composition layer) may be the same as the above range.

[0075] Component (C): Thermosetting resin component

[0076] Component (C) may contain, for example, a cationically polymerizable compound (hereinafter, sometimes referred to as “component (C1)”) and a thermal cationic polymerization initiator (hereinafter, sometimes referred to as “component (C2)”). Component (C) may be a component composed of component (C1) and component (C2). In addition, the first thermosetting resin component and the second thermosetting resin component refer to the thermosetting resin components contained in the first adhesive layer and the second adhesive layer, respectively. The types, combinations, and contents of the components (for example, component (C1), component (C2), etc.) contained in the first thermosetting resin component and the second thermosetting resin component may be the same as or different from each other.

[0077] Component (C1): Cationically polymerizable compound

[0078] Component (C1) is a compound that crosslinks by reacting with component (C2) by heat. In addition, component (C1) is a compound that does not have a radically polymerizable group that reacts by radicals, and component (C1) is not included in component (B1). From the viewpoint of further improving the effect of reducing the connection resistance and more excellent connection reliability, component (C1) may be a compound having one or more ring-opening polymerizable cyclic ether groups in the molecule. Component (C1) may be used alone or in combination of multiple types. As the compound having one or more ring-opening polymerizable cyclic ether groups in the molecule, for example, it may be at least one selected from the group consisting of oxetane compounds and alicyclic epoxy compounds. From the viewpoint of easily obtaining the desired melt viscosity, component (C1) preferably contains both at least one oxetane compound and at least one alicyclic epoxy compound.

[0079] As the oxetane compound of the (C1) component, as long as it is a compound having an oxetanyl group and not having a radically polymerizable group, it can be used without particular limitation. As commercially available products of the oxetane compound, for example, ETERNACOLL OXBP (trade name, manufactured by UBE Corporation), OXSQ, OXT-121, OXT-221, OXT-101, OXT-212 (trade name, manufactured by TOAGOSEI CO., LTD.) and the like can be cited. These can be used alone, or multiple compounds can be used in combination.

[0080] As the alicyclic epoxy compound of the (C1) component, as long as it is a compound having an alicyclic epoxy group (for example, epoxycyclohexyl) and not having a radically polymerizable group, it can be used without particular limitation. As commercially available products of the alicyclic epoxy compound, for example, EHPE3150, EHPE3150CE, CEL8010, CEL2021P, CEL2081 (trade name, manufactured by Daicel Corporation) and the like can be cited. These can be used alone, or multiple compounds can be used in combination.

[0081] (C2) component: Thermal cationic polymerization initiator

[0082] (C2) component is a thermal polymerization initiator that initiates polymerization by generating an acid or the like by heating. The (C2) component can be a salt compound composed of a cation and an anion. Regarding the (C2) component, for example, those having BF4 - , BR4 - (R represents a phenyl group substituted by two or more fluorine atoms or two or more trifluoromethyl groups.), PF6 - , SbF6 - , AsF6 - and other anions such as sulfonium salts, phosphonium salts, ammonium salts, diazonium salts, iodonium salts, anilinium salts and other onium salts can be cited. These can be used alone, or multiple ones can be used in combination.

[0083] From the viewpoint of storage stability, the (C2) component can be, for example, a salt compound having an anion containing boron as a constituent element, that is, BF4 - or BR4 - (R represents a phenyl group substituted by two or more fluorine atoms or two or more trifluoromethyl groups.). The anion containing boron as a constituent element can be BR4 - , and more specifically, it can be tetrakis(pentafluorophenyl)borate.

[0084] Since it has resistance to substances that can hinder curing relative to cationic curing, the onium salt as the component (C2) can be, for example, an anilinium salt. As anilinium salt compounds, for example, N,N-dialkylanilinium salts such as N,N-dimethylanilinium salt and N,N-diethylanilinium salt can be mentioned.

[0085] (C2) component can be an anilinium salt having an anion containing boron as a constituent element. As commercially available products of such salt compounds, for example, CXC-1821 (trade name, manufactured by King Industries, Inc.) etc. can be mentioned.

[0086] From the viewpoint of ensuring the formability and curability of the adhesive film for forming the first adhesive layer, the content of the component (C2) can be, for example, 0.1 to 25 parts by mass, 1 to 20 parts by mass, 3 to 18 parts by mass, or 5 to 15 parts by mass with respect to 100 parts by mass of the component (C1).

[0087] From the viewpoint of ensuring the curability of the adhesive film for forming the first adhesive layer, based on the total mass of the first adhesive layer, the content of the component (C) can be 5% by mass or more, 10% by mass or more, 15% by mass or more, or 20% by mass or more. From the viewpoint of ensuring the formability of the adhesive film for forming the first adhesive layer, based on the total mass of the first adhesive layer, the content of the component (C) can be 70% by mass or less, 60% by mass or less, 50% by mass or less, or 40% by mass or less. If the content of the component (C) is within the above range, the effects of the present invention tend to be significantly exhibited. In addition, the content of the component (C) in the composition or the composition layer (based on the total mass of the composition or the composition layer) can be the same as the above range.

[0088] [Other components]

[0089] The first adhesive layer 1 can further contain other components in addition to the cured products of the components (A) and (B) and the component (C). As other components, for example, thermoplastic resins (hereinafter sometimes referred to as “component (D)”), coupling agents (hereinafter sometimes referred to as “component (E)”), fillers (hereinafter sometimes referred to as “component (F)”), ion scavengers (hereinafter sometimes referred to as “component G”) etc. can be mentioned.

[0090] As the component (D), for example, phenoxy resin, polyester resin, polyamide resin, polyurethane resin, polyester polyurethane resin, acrylate rubber, epoxy resin (solid at 25°C), etc. can be cited. These can be used alone or in combination of multiple kinds. By the composition containing the components (A), (B) and (C) further containing the component (D), a composition layer (further the first adhesive layer 1) can be easily formed from the composition. Among these, the component (D) can be, for example, phenoxy resin.

[0091] From the viewpoint of resin excludability during encapsulation, the weight-average molecular weight (Mw) of the component (D) can be, for example, 5000 to 200000, 10000 to 100000, 20000 to 80000 or 40000 to 60000. In addition, Mw refers to the value measured by gel permeation chromatography (GPC) and converted using a calibration curve based on standard polystyrene.

[0092] Based on the total mass of the first adhesive layer, the content of the component (D) can be 1% by mass or more, 5% by mass or more, 10% by mass or more or 20% by mass or more, and can also be 70% by mass or less, 60% by mass or less, 50% by mass or less or 40% by mass or less. In addition, the content of the component (D) in the composition or the composition layer (based on the total mass of the composition or the composition layer) can be the same as the above range.

[0093] As the component (E), for example, silane coupling agents having organic functional groups such as (meth)acryloyl group, mercapto group, amino group, imidazolyl group, epoxy group, etc., silane compounds such as tetraalkoxysilane, tetraalkoxy titanate derivatives, polydialkyl titanate derivatives, etc. can be cited. These can be used alone or in combination of multiple kinds. By the first adhesive layer 1 containing the component (E), the adhesiveness can be further improved. The component (E) can be, for example, a silane coupling agent. Based on the total mass of the first adhesive layer, the content of the component (E) can be 0.1 to 10% by mass. In addition, the content of the component (E) in the composition or the composition layer (based on the total mass of the composition or the composition layer) can be the same as the above range.

[0094] As the component (F), for example, non-conductive fillers (e.g., non-conductive particles) can be cited. The component (F) can be either an inorganic filler or an organic filler. As the inorganic filler, for example, metal oxide fine particles such as silica fine particles, alumina fine particles, silica-alumina fine particles, titanium dioxide fine particles, zirconium dioxide fine particles, etc.; inorganic fine particles such as metal nitride fine particles. As the organic filler, for example, organic fine particles such as silicone fine particles, methacrylate / butadiene / styrene fine particles, acrylic / silicone fine particles, polyamide fine particles, polyimide fine particles, etc. These can be used alone as one kind, or a plurality of them can be used in combination. The component (F) can be, for example, silica fine particles. Based on the total mass of the first adhesive layer, the content of the component (F) can be 0.1 to 10% by mass. In addition, the content of the component (F) in the composition or the composition layer (based on the total mass of the composition or the composition layer) can be the same as the above range.

[0095] As the component (G), metal hydroxides or metal oxides can be cited. The component (G) can, for example, contain at least one metal compound selected from the group consisting of aluminum hydroxide, alumina, magnesium hydroxide, magnesia, zirconium hydroxide, zirconia, bismuth hydroxide, bismuth oxide, calcium hydroxide, calcia, tin hydroxide, stannic oxide, manganese hydroxide, manganic oxide, antimony hydroxide, antimony oxide, silicon hydroxide, silica, titanium hydroxide, and titania. From the viewpoint of improving the dispersibility in an organic solvent, these metal compounds can be compounds that have been subjected to surface treatment.

[0096] From the viewpoint of insulation maintenance, the component (G) can contain at least one selected from the group consisting of aluminum hydroxide, magnesium hydroxide, and calcium hydroxide. From the viewpoint of obtaining more excellent insulation maintenance, the metal oxide is preferably at least one selected from the group consisting of silica, alumina, magnesia, antimony oxide, stannic oxide, titania, manganic oxide, and zirconia. The component (G) can be used alone as one kind, or two or more kinds can be used in combination.

[0097] As commercially available products of the ion scavenger, for example, "IXEPLAS-A1", "IXEPLAS-A2", "IXEPLAS-A3" (trade names, manufactured by TOAGOSEI CO., LTD.), "DHT-4A-2" (trade name, manufactured by Kyowa Chemical Industry Co., Ltd.), "DHT-4A" (trade name, manufactured by Kyowa Chemical Industry Co., Ltd.) can be cited.

[0098] (G) component may be particles containing the above metal compound. The primary particle size of (G) component may be 10 nm or more, may be 20 nm or more, may be 1000 nm or less, and may be 600 nm or less. The average primary particle size of (G) component can be measured, for example, using a scanning electron microscope.

[0099] Commercially available ion scavengers can be used after removing aggregates, etc., to be suitable for coating of thin films. For example, by performing air classification or micronization treatment, the D95 of the particle size distribution after solvent dispersion can be made less than 5 μm. If D95 is less than 5 μm, it is easy to disperse the particles of the ion scavenger well, and the insulation maintenance between adjacent circuits can be further improved. In addition, D95 can also be made less than 3 μm, and the above-mentioned effect can be further improved.

[0100] Based on the total mass of the first adhesive layer (excluding conductive particles and inorganic fillers), the content of (G) component can be 0.1 to 10% by mass, and can also be 0.3 to 5% by mass. If the content of (G) component is 0.1% by mass or more, it is easy to ensure the insulation maintenance between adjacent circuits. If it is 10% by mass or less, it is difficult for the connection resistance between the opposing electrodes to increase.

[0101] [Other additives]

[0102] The first adhesive layer 1 may further contain other additives such as softeners, accelerators, anti-degradants, colorants, flame retardants, thixotropic agents, etc. Based on the total mass of the first adhesive layer, the content of other additives can be, for example, 0.1 to 10% by mass. In addition, the content of other additives in the composition or composition layer (based on the total mass of the composition or composition layer) can be the same as the above range.

[0103] The thickness d1 of the first adhesive layer 1 can be, for example, 5 μm or less. The thickness d1 of the first adhesive layer 1 can be 4.5 μm or less, or 4.0 μm or less. Since the thickness d1 of the first adhesive layer 1 is 5 μm or less, conductive particles during circuit connection can be captured more effectively. The thickness d1 of the first adhesive layer 1 can be, for example, 0.1 μm or more, 0.5 μm or more, or 0.7 μm or more. In addition, the thickness d1 of the first adhesive layer 1 can be obtained, for example, by sandwiching an adhesive film with two glasses (thickness: about 1 mm), casting a resin composition composed of 100 g of bisphenol A type epoxy resin (trade name: JER811, manufactured by Mitsubishi Chemical Corporation) and 10 g of a curing agent (trade name: Epomount curing agent, manufactured by Refine Tec Ltd.), grinding the cross-section using a grinding machine, and measuring using a scanning electron microscope (SEM, trade name: SE-8020, manufactured by Hitachi High-Tech Science Corporation). And, as Figure 1 shown, when a part of the conductive particle 4 exposes from the surface of the first adhesive layer 1 (for example, protrudes toward the second adhesive layer 2 side), the distance from the surface 2a on the side opposite to the second adhesive layer 2 side in the first adhesive layer 1 to the boundary S between the first adhesive layer 1 and the second adhesive layer 2 at the separated part of the adjacent conductive particles 4, 4 (the distance represented by d1 in Figure 1 ) is the thickness of the first adhesive layer 1, and the exposed part of the conductive particle 4 is not included in the thickness of the first adhesive layer 1. The length of the exposed part of the conductive particle 4 can be, for example, 0.1 μm or more and can also be 5 μm or less.

[0104] <Second Adhesive Layer>

[0105] The second adhesive layer 2 contains the (C) component. The (C1) component and the (C2) component used in the (C) component (i.e., the second thermosetting resin component) in the second adhesive layer 2 are the same as the (C1) component and the (C2) component used in the (C) component (i.e., the first thermosetting resin component) in the first adhesive layer 1, so detailed description is omitted here. The second thermosetting resin component can be the same as or different from the first thermosetting resin component.

[0106] From the perspective of maintaining reliability, based on the total mass of the second adhesive layer, the content of component (C) can be 5% by mass or more, 10% by mass or more, 15% by mass or more, or 20% by mass or more. From the perspective of preventing resin bleeding defects on the reel, which is a type of supply method, based on the total mass of the second adhesive layer, the content of component (C) can be 70% by mass or less, 60% by mass or less, 50% by mass or less, or 40% by mass or less.

[0107] The second adhesive layer 2 may further contain other components and other additives in the first adhesive layer 1. The preferred modes of other components and other additives are the same as those of the first adhesive layer 1.

[0108] Based on the total mass of the second adhesive layer, the content of component (D) can be 1% by mass or more, 5% by mass or more, or 10% by mass or more, and can also be 80% by mass or less, 60% by mass or less, or 40% by mass or less.

[0109] Based on the total mass of the second adhesive layer, the content of component (E) can be 0.1 to 10% by mass.

[0110] Based on the total mass of the second adhesive layer, the content of component (F) can be 1% by mass or more, 5% by mass or more, or 10% by mass or more, and can also be 70% by mass or less, 50% by mass or less, or 30% by mass or less.

[0111] Based on the total mass of the second adhesive layer (excluding conductive particles and inorganic fillers), the content of component (G) can be 0.1 to 10% by mass, and can also be 0.3 to 5% by mass. If the content of component (G) is 0.1% by mass or more, it is easy to ensure the insulation maintenance between adjacent circuits. If it is 10% by mass or less, it is difficult to increase the connection resistance between opposing electrodes.

[0112] Based on the total mass of the second adhesive layer, the content of other additives can be, for example, 0.1 to 10% by mass.

[0113] The thickness d2 of the second adhesive layer 2 can be appropriately set according to the height of the electrodes of the circuit components to be bonded, etc. From the viewpoint of being able to sufficiently fill the space between the electrodes to seal the electrodes and obtain better connection reliability, the thickness d2 of the second adhesive layer 2 can be 5 μm or more, or 7 μm or more, and can also be 15 μm or less, or 11 μm or less. In addition, the thickness d2 of the second adhesive layer 2 can be obtained, for example, by the same method as the measurement method of the thickness d1 of the first adhesive layer 1. And, when a part of the conductive particles 4 protrudes from the surface of the first adhesive layer 1 (for example, protrudes toward the second adhesive layer 2), the distance from the surface 3a on the side opposite to the first adhesive layer 1 side in the second adhesive layer 2 to the boundary S between the first adhesive layer 1 and the second adhesive layer 2 located at the separated part of the adjacent conductive particles 4, 4 (the distance represented by d2 in Figure 1 is the thickness of the second adhesive layer 2.

[0114] The thickness of the adhesive film 10 (the total thickness of all the layers constituting the adhesive film 10, in Figure 1 is the sum of the thickness d1 of the first adhesive layer 1 and the thickness d2 of the second adhesive layer 2) can be, for example, 5 μm or more, or 8 μm or more, and can also be 30 μm or less, or 20 μm or less.

[0115] The adhesive film for circuit connection of the present embodiment may contain conductive particles and include a region A containing a component (C1), a component (C2), and a component (G). In this region A, the component (C1) contains a compound having one or more ring-opening polymerizable cyclic ether groups in the molecule, the component (C2) contains an anilinium salt, and the component (G) contains at least one metal compound selected from the group consisting of aluminum hydroxide, alumina, magnesium hydroxide, magnesia, zirconium hydroxide, zirconia, bismuth hydroxide, bismuth oxide, calcium hydroxide, calcium oxide, tin hydroxide, tin oxide, manganese hydroxide, manganese oxide, antimony hydroxide, antimony oxide, silicon hydroxide, silica, titanium hydroxide, and titanium oxide. According to the adhesive film for circuit connection having such a region A, conduction between the opposing electrodes of the circuit connection structure can be sufficiently ensured, and insulation between adjacent circuits can be sufficiently maintained. In the adhesive film 10, for example, the first adhesive layer and the second adhesive layer may be the above-mentioned region A, or one of the first adhesive layer and the second adhesive layer may be the above-mentioned region A.

[0116] When the first adhesive layer and the second adhesive layer are the region A, the range in the thickness direction of the film of the region A can be made the same as the total value of the thickness d1 of the first adhesive layer 1 and the thickness d2 of the second adhesive layer 2 described above.

[0117] Further, in the case where region A includes region P in which a cured product containing component (B) further in the thickness direction of the thin film is provided, the first adhesive layer may be region P. At this time, conductive particles may be dispersed in region P. Further, the range in the thickness direction of the thin film of region P can be set in the same manner as the thickness of the above-described first adhesive layer. The content of each component in region P can also be set in the same manner as the first adhesive layer.

[0118] In addition, in the case where region A includes region S in which a cured product containing the above-described specific component (C1), the above-described specific component (C2), and the above-described specific component (G) and not containing component (B) is provided in the thickness direction of the thin film, the second adhesive layer may be region S. At this time, the range in the thickness direction of the thin film of region S can be set in the same manner as the thickness of the above-described second adhesive layer. The content of each component in region S can also be set in the same manner as the second adhesive layer.

[0119] The minimum melt viscosity of the adhesive film 10 is 450 to 1600 Pa·s. The minimum melt viscosity of the adhesive film 10 may be 500 Pa·s or more, 600 Pa·s or more, 700 Pa·s or more, or 800 Pa·s or more. If the minimum melt viscosity of the adhesive film 10 is 450 Pa·s or more, deformation of the plastic substrate during thermocompression bonding can be suppressed and occurrence of circuit disconnection can be prevented. The minimum melt viscosity of the adhesive film 10 may be 1500 Pa·s or less, 1400 Pa·s or less, 1300 Pa·s or less, 1200 Pa·s or less, 1100 Pa·s or less, or 1000 Pa·s or less. If the minimum melt viscosity of the adhesive film 10 is 1600 Pa·s or less, a decrease in the exudability of the resin during circuit connection can be suppressed, and thus the connection resistance between the opposing electrodes of the circuit connection structure can be reduced and good conduction characteristics can be ensured. In addition, the minimum melt viscosity of the adhesive film can be obtained, for example, by the following method.

[0120] [Method for Measuring Minimum Melt Viscosity]

[0121] Laminated bodies are formed by laminating the respective adhesive films using a laminator so that the thickness thereof reaches 500 μm or more. The PET that has been subjected to a release treatment is peeled off from the obtained laminated body, and cut into 10.0 mm × 10.0 mm to obtain measurement specimens. The minimum melt viscosity of the obtained measurement specimens (trade name: ARES-G2, manufactured by TA Instruments, heating rate: 10°C / minute) is measured using a viscoelasticity measuring device.

[0122] In the adhesive film 10, the second adhesive layer 2 is generally thicker than the first adhesive layer 1. Therefore, the minimum melt viscosity of the adhesive film 10 tends to vary according to the second adhesive layer 2. Regarding the adjustment of the minimum melt viscosity of the adhesive film 10, for example, it can be carried out by adjusting the type, content, etc. of the constituent components (especially, component (D)) contained in the second adhesive layer 2. Also, the minimum melt viscosity of the adhesive film 10 can be adjusted, for example, by using a component with a small particle size as component (F). By using a component with a small particle size as component (F), the minimum melt viscosity of the adhesive film 10 tends to increase.

[0123] In the adhesive film 10, the conductive particles 4 are dispersed in the first adhesive layer 1. Therefore, the adhesive film 10 is an anisotropic conductive adhesive film having anisotropic conductivity. The adhesive film 10 is interposed between a first circuit component having a first electrode and a second circuit component having a second electrode, and is used for thermocompression bonding the first circuit component and the second circuit component to electrically connect the first electrode and the second electrode to each other.

[0124] According to the adhesive film 10, even when connecting circuit components to each other at a low pressure, conduction between the opposing electrodes of the circuit connection structure can be sufficiently ensured, and insulation between adjacent circuits can be sufficiently maintained. Such an adhesive film for circuit connection can be applied to COP packaging. More specifically, it can be applied to the connection between a plastic substrate formed with circuit electrodes in an organic EL display and an IC chip such as a driving IC.

[0125] The above has described the adhesive film of the present embodiment, but the present invention is not limited to the above embodiment.

[0126] The adhesive film can be composed of, for example, two layers, namely the first adhesive layer and the second adhesive layer, or can be composed of three or more layers including the first adhesive layer and the second adhesive layer. The adhesive film can have, for example, a structure further including a third adhesive layer provided on the side of the first adhesive layer opposite to the second adhesive layer.

[0127] The third adhesive layer contains component (C). The component (C1) and component (C2) used in the component (C) (i.e., the third thermosetting resin component) in the third adhesive layer are the same as the component (C1) and component (C2) used in the component (C) (i.e., the first thermosetting resin component) in the first adhesive layer 1, so detailed description is omitted here. The third thermosetting resin component can be the same as or different from the first thermosetting resin component. The third thermosetting resin component can be the same as or different from the second thermosetting resin component.

[0128] In terms of imparting good transferability and peel resistance, based on the total mass of the third adhesive layer, the content of component (C) can be 5% by mass or more, 10% by mass or more, 15% by mass or more, or 20% by mass or more. In terms of imparting good semi-cutability and anti-sticking property (inhibiting resin bleeding on the reel), based on the total mass of the third adhesive layer, the content of component (C) can be 70% by mass or less, 60% by mass or less, 50% by mass or less, or 40% by mass or less.

[0129] The third adhesive layer may further contain other components and other additives in the first adhesive layer 1. In terms of taking into account both the conduction characteristics between the opposing electrodes and the insulation maintenance between adjacent circuits, the third adhesive layer may have the structure of region A described above, or may have the structure of region S. The preferred modes of other components and other additives are the same as those of the first adhesive layer 1.

[0130] Based on the total mass of the third adhesive layer, the content of component (D) can be 10% by mass or more, 20% by mass or more, or 30% by mass or more, and can also be 80% by mass or less, 70% by mass or less, or 60% by mass or less.

[0131] Based on the total mass of the third adhesive layer, the content of component (E) can be 0.1 to 10% by mass.

[0132] Based on the total mass of the third adhesive layer, the content of component (F) can be 1% by mass or more, 3% by mass or more, or 5% by mass or more, and can also be 50% by mass or less, 40% by mass or less, or 30% by mass or less.

[0133] Based on the total mass of the third adhesive layer (excluding conductive particles and inorganic fillers), the content of component (G) can be 0.1 to 10% by mass, or can also be 0.3 to 5% by mass. If the content of component (G) is 0.1% by mass or more, it is easy to ensure the insulation maintenance between adjacent circuits, and if it is 10% by mass or less, it is difficult to increase the connection resistance between the opposing electrodes.

[0134] Based on the total mass of the third adhesive layer, the content of other additives can be, for example, 0.1 to 10% by mass.

[0135] The thickness of the third adhesive layer can be appropriately set according to the minimum melt viscosity of the adhesive film, the height of the electrodes of the circuit components to be bonded, etc. The thickness of the third adhesive layer is preferably smaller than the thickness d2 of the second adhesive layer 2. From the viewpoint of being able to sufficiently fill the space between the electrodes to seal the electrodes and obtaining better connection reliability, the thickness of the third adhesive layer can be 0.2 μm or more and can also be 3.0 μm or less. In addition, the thickness of the third adhesive layer can be obtained, for example, by the same method as the method for measuring the thickness d1 of the first adhesive layer 1.

[0136] When the first adhesive layer, the second adhesive layer, and the third adhesive layer are in region A, the range in the thickness direction of the film in region A can be made the same as the total value of the thickness of the first adhesive layer, the thickness of the second adhesive layer, and the thickness of the third adhesive layer. And when the third adhesive layer is in region S, the range in the thickness direction of the region S can be made the same as the thickness of the third adhesive layer.

[0137] The adhesive film for circuit connection of the above embodiment can be a conductive adhesive film that does not have anisotropic conductivity.

[0138] <Manufacturing method of adhesive film for circuit connection>

[0139] A manufacturing method of an adhesive film for circuit connection according to an embodiment can include, for example: a step (the first step) of irradiating a light on a composition layer formed of a composition containing component (A), component (B), and component (C) (the first thermosetting resin component) and optionally containing component (G) to form the first adhesive layer; and a step (the second step) of laminating a second adhesive layer containing component (C) (the second thermosetting resin component) and optionally containing component (G) on the first adhesive layer. This manufacturing method can further include the following step (the third step): laminating a third adhesive layer containing component (C) (the third thermosetting resin component) and optionally containing component (G) on the layer of the first adhesive layer on the side opposite to the second adhesive layer. At this time, the second step can be carried out first, or the third step can be carried out first. When the third step is carried out first, the third adhesive layer is laminated on the side of the first adhesive layer opposite to the side where the second adhesive layer is to be laminated.

[0140] In the first step, for example, first, a composition containing component (A), component (B), component (C), and other components and other additives such as component (G) added as needed is stirred, mixed, kneaded, etc. in an organic solvent to dissolve or disperse it, thereby preparing a varnish composition (varnish-like first adhesive composition). Thereafter, using a knife coater, a roll coater, an applicator, a beveled wheel coater, a die coater, etc., the varnish composition is coated on a substrate that has been subjected to a release treatment, and then the organic solvent is volatilized by heating to form a composition layer formed by the composition on the substrate. At this time, by adjusting the coating amount of the varnish composition, the thickness of the finally obtained first adhesive layer (first adhesive film) can be adjusted. Next, light is irradiated on the composition layer formed by the composition to cure component (B) in the composition layer, and a first adhesive layer is formed on the substrate. The first adhesive layer can be referred to as a first adhesive film.

[0141] Regarding the organic solvent used in the preparation of the varnish composition, there is no particular limitation as long as it has the property of uniformly dissolving or dispersing each component. As such an organic solvent, for example, toluene, acetone, methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate, propyl acetate, butyl acetate, etc. can be cited. These organic solvents can be used alone or in combination of two or more. Stirring, mixing, or kneading during the preparation of the varnish composition can be carried out, for example, using a stirrer, a mortar machine, a three-roll mill, a ball mill, a bead mill, a homogenizing disperser, etc.

[0142] Regarding the substrate, there is no particular limitation as long as it has heat resistance capable of withstanding the heating conditions during the volatilization of the organic solvent. As such a substrate, for example, a substrate (such as a film) made of 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, synthetic rubber-based, liquid crystal polymer, etc. can be used.

[0143] The heating conditions for volatilizing the organic solvent from the varnish composition coated on the substrate can be appropriately set according to the organic solvent used, etc. The heating conditions can be, for example, 40 to 120 °C and 0.1 to 10 minutes.

[0144] In the first adhesive layer, a part of the solvent can remain without being removed. Based on the total mass of the first adhesive layer, the content of the solvent in the first adhesive layer can be, for example, 10% by mass or less.

[0145] In the light irradiation in the curing process, it is preferable to use irradiation light having a wavelength in the range of 150 to 750 nm (for example, ultraviolet light). Regarding the light irradiation, for example, a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a xenon lamp, a metal halide lamp, an LED light source, etc. can be used. The cumulative light amount of the light irradiation can be appropriately set, for example, it can be 500 to 3000 mJ / cm 2 .

[0146] The second step is a step of laminating a second adhesive layer on the first adhesive layer. In the second step, for example, first, using the component (C) and other components such as the component (G) added as needed, other additives, and without performing light irradiation, in the same manner as in the first step, a second adhesive layer is formed on the substrate to obtain a second adhesive film. Then, by laminating the first adhesive film and the second adhesive film, the second adhesive layer can be laminated on the first adhesive layer. Also, in the second step, for example, a varnish composition (varnish-like second adhesive composition) obtained by using the component (C) and other components such as the component (G) added as needed is coated on the first adhesive layer, and the organic solvent is volatilized, whereby the second adhesive layer can also be laminated on the first adhesive layer.

[0147] As a method of laminating the first adhesive film and the second adhesive film, for example, methods such as hot pressing, roll lamination, and vacuum lamination can be cited. Regarding the lamination, for example, it can be carried out under temperature conditions of 0 to 80°C.

[0148] In the second adhesive layer, a part of the solvent may remain without being removed. Based on the total mass of the second adhesive layer, the content of the solvent in the second adhesive layer can be, for example, 10% by mass or less.

[0149] The third step is a step of laminating a third adhesive layer on the layer of the first adhesive layer on the side opposite to the second adhesive layer. In the third step, for example, first, in the same manner as in the second step, a third adhesive layer is formed on the substrate to obtain a third adhesive film. Then, the third adhesive film is laminated on the side of the first adhesive film opposite to the second adhesive film, whereby the third adhesive layer can be laminated on the layer of the first adhesive layer on the side opposite to the second adhesive layer. Also, in the third step, for example, in the same manner as in the second step, a varnish composition (varnish-like third adhesive composition) is coated on the layer of the first adhesive layer on the side opposite to the second adhesive layer, and the organic solvent is volatilized, whereby the third adhesive layer can also be laminated on the first adhesive layer. The lamination method and its conditions are the same as those in the second step.

[0150] In the third adhesive layer, a part of the solvent may remain without being removed. Based on the total mass of the third adhesive layer, the content of the solvent in the third adhesive layer may be, for example, 10% by mass or less.

[0151] <Circuit connection adhesive composition>

[0152] The circuit connection adhesive composition of the present embodiment contains a cationically polymerizable compound, a thermal cationic polymerization initiator, and an ion scavenger. The cationically polymerizable compound includes a compound having one or more ring-opening polymerizable cyclic ether groups in the molecule. The thermal cationic polymerization initiator includes anilinium salt, and the ion scavenger includes at least one metal compound selected from the group consisting of aluminum hydroxide, alumina, magnesium hydroxide, magnesia, zirconium hydroxide, zirconia, bismuth hydroxide, bismuth oxide, calcium hydroxide, calcium oxide, tin hydroxide, tin oxide, manganese hydroxide, manganese oxide, antimony hydroxide, antimony oxide, silicon hydroxide, silica, titanium hydroxide, and titanium oxide.

[0153] According to the circuit connection adhesive composition of the present embodiment, regions A, P, S, the first adhesive layer, the second adhesive layer, the third adhesive layer, etc. in the above-mentioned circuit connection adhesive film can be formed.

[0154] The circuit connection adhesive composition of the present embodiment can further contain conductive particles and can further contain a photocurable resin component. Such a circuit connection adhesive composition can form region P or the first adhesive layer in the above-mentioned circuit connection adhesive film.

[0155] The composition of the circuit connection adhesive composition of the present embodiment can be set in the same manner as the composition in the above-mentioned first adhesive layer, second adhesive layer, or third adhesive layer.

[0156] <Circuit connection structure and its manufacturing method>

[0157] Hereinafter, a circuit connection structure using the above-mentioned circuit connection adhesive film 10 as a circuit connection material and its manufacturing method will be described.

[0158] Figure 2 is a schematic cross-sectional view showing an embodiment of the circuit connection structure. As Figure 2 shown, the circuit connection structure 20 includes: a first circuit component 13 having a first electrode 12 formed on a first circuit board 11 and a main surface 11a of the first circuit board 11; a second circuit component 16 having a second electrode 15 formed on a second circuit board 14 and a main surface 14a of the second circuit board 14; and a circuit connection portion 17 disposed between the first circuit component 13 and the second circuit component 16 to electrically connect the first electrode 12 and the second electrode 15 to each other.

[0159] The first circuit component 13 and the second circuit component 16 may be the same as or different from each other. The first circuit component 13 and the second circuit component 16 may be a glass substrate or a plastic substrate formed with circuit electrodes; a printed circuit board; a ceramic circuit board; a flexible circuit board; an IC chip such as a driving IC, etc. The first circuit substrate 11 and the second circuit substrate 14 may be formed of inorganic substances such as semiconductors, glass, and ceramics, organic substances such as polyimide and polycarbonate, composites such as glass / epoxy, etc. The first circuit substrate 11 may be a plastic substrate. The first circuit component 13 may be, for example, a plastic substrate formed with circuit electrodes (a plastic substrate made of organic substances such as polyimide, polycarbonate, polyethylene terephthalate, and cycloolefin polymer), and the second circuit component 16 may be, for example, an IC chip such as a driving IC. The plastic substrate formed with electrodes may also be a substrate on which, for example, a pixel driving circuit such as an organic TFT or a plurality of organic EL elements R, G, and B are regularly arranged in a matrix to form a display area.

[0160] The first electrode 12 and the second electrode 15 may be electrodes containing metals such as gold, silver, tin, ruthenium, rhodium, palladium, osmium, iridium, platinum, copper, aluminum, molybdenum, titanium, etc., oxides such as indium tin oxide (ITO), indium zinc oxide (IZO), indium gallium zinc oxide (IGZO), etc. The first electrode 12 and the second electrode 15 may be electrodes formed by laminating two or more of these metals, oxides, etc. The electrode formed by laminating two or more may be two or more layers, or may be three or more layers. When the first circuit component 13 is a plastic substrate, the first electrode 12 may be an electrode having a titanium layer on the outermost surface. The first electrode 12 and the second electrode 15 may be circuit electrodes or bump electrodes. At least one of the first electrode 12 and the second electrode 15 may be a bump electrode. In Figure 2 it is a mode in which the first electrode 12 is a circuit electrode and the second electrode 15 is a bump electrode.

[0161] The circuit connection portion 17 includes the cured product of the above-mentioned adhesive film 10. The circuit connection portion 17 may be made of the cured product of the above-mentioned adhesive film 10. The circuit connection portion 17 has, for example: a first region 18, located on the side of the first circuit component 13 in the direction in which the first circuit component 13 and the second circuit component 16 face each other (hereinafter referred to as the "opposing direction"), and made of the cured product of the (B) component other than the conductive particles 4 in the above-mentioned first adhesive layer and the cured product of the (C) component, etc.; a second region 19, located on the side of the second circuit component 16 in the opposing direction, and made of the cured product of the (C) component, etc. in the above-mentioned second adhesive layer; and conductive particles 4, at least interposed between the first electrode 12 and the second electrode 15 to electrically connect the first electrode 12 and the second electrode 15 to each other. As Figure 2As shown, the circuit connection portion 17 may not have two distinct regions between the first region 18 and the second region 19, or may form one region by mixing the cured product from the first adhesive layer and the cured product from the second adhesive layer.

[0162] Examples of the circuit connection structure include: a flexible organic electroluminescent color display (organic EL display) in which organic EL elements are regularly arranged and connected to a drive circuit element as an image display driver, a touch panel in which an organic EL element is regularly arranged and connected to a position input element such as a touch panel, and the like. The circuit connection structure can be applied to various displays such as smartphones, tablet computers, televisions, vehicle navigation systems, wearable terminals, etc.; furniture; household appliances; daily necessities, etc.

[0163] Figure 3 It is a schematic cross-sectional view showing an embodiment of a method for manufacturing a circuit connection structure. Figure 3 (a) and Figure 3 (b) are schematic cross-sectional views showing each process. As Figure 3 shown, the manufacturing method of the circuit connection structure 20 includes the following steps: interposing the adhesive film 10 between the first circuit component 13 having the first electrode 12 and the second circuit component 16 having the second electrode 15, and thermocompression bonding the first circuit component 13 and the second circuit component 16 to electrically connect the first electrode 12 and the second electrode 15 to each other.

[0164] Specifically, as Figure 3 (a) shows, first, prepare the first circuit component 13 having the first electrode 12 formed on the first circuit board 11 and the main surface 11a of the first circuit board 11, and the second circuit component 16 having the second electrode 15 formed on the second circuit board 14 and the main surface 14a of the second circuit board 14.

[0165] Next, arrange the first circuit component 13 and the second circuit component 16 so that the first electrode 12 and the second electrode 15 face each other, and arrange the adhesive film 10 between the first circuit component 13 and the second circuit component 16. For example, as Figure 3 (a) shows, make the first adhesive layer 1 side face the main surface 11a of the first circuit board 11 and laminate the adhesive film 10 on the first circuit component 13. Next, arrange the second circuit component 16 on the first circuit component 13 laminated with the adhesive film 10 so that the first electrode 12 on the first circuit board 11 and the second electrode 15 on the second circuit board 14 face each other.

[0166] And, as Figure 3(As shown in (b)), while heating the first circuit component 13, the adhesive film 10, and the second circuit component 16, pressure is applied to the first circuit component 13 and the second circuit component 16 in the thickness direction, thereby thermocompression bonding the first circuit component 13 and the second circuit component 16 to each other. At this time, in Figure 3 (b), as shown by the arrow, the second adhesive layer 2 has an uncured thermosetting component that can flow. Therefore, it flows in a manner that fills the gaps between the second electrodes 15 and is cured by the above heating. As a result, the first electrode 12 and the second electrode 15 are electrically connected to each other via the conductive particles 4, and the first circuit component 13 and the second circuit component 16 are bonded to each other, thereby enabling the acquisition of Figure 2 the circuit connection structure 20 shown in. In the manufacturing method of the circuit connection structure 20 of the present embodiment, since a part of the first adhesive layer 1 is a layer cured by light irradiation, the conductive particles in the first adhesive layer 1 are suppressed from flowing, and the first adhesive layer 1 hardly flows during the above thermocompression bonding. The conductive particles are effectively captured between the opposing electrodes, so the connection resistance between the opposing first electrode 12 and the second electrode 15 can be reduced. And if the thickness of the first adhesive layer is 5 μm or less, it tends to be able to capture the conductive particles more effectively during circuit connection.

[0167] The heating temperature during thermocompression bonding can be appropriately set. For example, it can be 50 to 190 °C. Regarding the pressure, as long as it is within the range that does not damage the adherend, there is no particular limitation. In the case of COP packaging, for example, the area-converted pressure on the bump electrode can be 0.1 to 50 MPa, or it can be 40 MPa or less, or it can be 0.1 to 40 MPa. And in the case of COG packaging, for example, the area-converted pressure on the bump electrode can be 10 to 100 MPa. These heating and pressurization times can be within the range of 0.5 to 120 seconds.

[0168] Examples

[0169] Hereinafter, examples will be given to illustrate the present invention more specifically. However, the present invention is not limited to these examples.

[0170] [Production of the first adhesive layer and the second adhesive layer]

[0171] In the production of the first adhesive layer and the second adhesive layer, the following materials were used.

[0172] (A) Component: Conductive particles

[0173] A-1: Conductive particles with an average particle diameter of 3.2 μm were used. In these conductive particles, the surface of the plastic core was Ni-plated, and the outermost surface was Pd-displacement plated.

[0174] (B) Component: Photocurable resin component

[0175] (B1) Component: Free-radical polymerizable compound

[0176] B1-1: A-BPEF70T (Ethoxylated fluorene type bis(meth)acrylate (2-functional), manufactured by SHIN-NAKAMURA CHEMICAL CO,LTD.), using a substance diluted with toluene to a non-volatile component of 70% by mass

[0177] B1-2: Ripoxy VR-90 (Bisphenol A type epoxy (meth)acrylate (2-functional) (vinyl ester resin), manufactured by SHOWA DENKO K.K.)

[0178] (B2) Component: Photo radical polymerization initiator

[0179] B2-1: Irgacure907 (Compound having an α-aminoalkyl phenyl ketone structure, manufactured by BASF), using a substance diluted with MEK to a non-volatile component of 10% by mass

[0180] (C) Component: Thermosetting resin component

[0181] (C1) Component: Cationic polymerizable compound

[0182] C1-1: ETERNACOLL OXBP (3-Ethyl-3-hydroxymethyloxetane, manufactured by UBE Corporation)

[0183] C1-2: EHPE3150 (Adduct of 1,2-epoxy-4-(2-oxiranyl)cyclohexane with 2,2-bis(hydroxymethyl)-1-butanol, manufactured by Daicel Corporation)

[0184] C1-3: CELLOXIDE 8010 (Bis-7-oxabicyclo[4.1.0]heptane, manufactured by Daicel Corporation)

[0185] C1-4: OX-SQ TX-100 (Derivative of poly({3-[(3-ethyl-3-oxetanylmethoxy)propyl}silsesquioxane), manufactured by TOAGOSEI CO.,LTD.)

[0186] (C2) Component: Thermal cationic polymerization initiator

[0187] C2-1: CXC-1821 (manufactured by King Industries,Inc.)

[0188] (D) Component: Thermoplastic resin

[0189] D-1: Phenotohto YP-50S (Bisphenol A type phenoxy resin, weight-average molecular weight: 60,000, glass transition temperature: 84 °C, manufactured by NIPPON STEEL Chemical&Material Co.,Ltd.), use the substance diluted with MEK to a non-volatile component of 40 mass%

[0190] D-2: TOPR-300 (High Tg type epoxy resin, epoxy equivalent: 900 - 1,000, softening point: 120 °C, manufactured by NIPPONSTEEL Chemical&Material Co.,Ltd.), use the substance diluted with MEK to a non-volatile component of 60 mass%

[0191] D-3: Phenotohto ZX-1356-2 (Copolymer type phenoxy resin of bisphenol A type and bisphenol F type, weight-average molecular weight: 70000, glass transition temperature: 71 °C, manufactured by NIPPON STEEL Chemical&Mat erial Co.,Ltd.), use the substance diluted with MEK to a non-volatile component of 40 mass%

[0192] (E) Component: Coupling agent

[0193] E-1: SH-6040 (3-Glycidoxypropyltrimethoxysilane, manufactured by Dow Corning Toray Co.,Ltd.)

[0194] (F) Component: Filler

[0195] F-1: ADMAFINE SE2050 (Silica microparticles, manufactured by ADMATECHS COMPANY LIMITED)

[0196] (G) Component: Ion scavenger

[0197] G-1: IXEPLAS-A1 (Zr, Mg, Al-based ion scavenger, manufactured by TOAGOSEI CO.,LTD., primary particle size 500nm)

[0198] G-2: IXEPLAS-A2 (Zr, Mg, Al-based ion scavenger, manufactured by TOAGOSEI CO.,LTD., primary particle size 200nm)

[0199] G-3: IXEPLAS-A3 (Surface-treated type of IXEPLAS-Al, manufactured by TOAGOSEI CO.,LTD.)

[0200] G-4: DHT-4A-2 (an ion scavenger of Mg, Al series, manufactured by Kyowa Chemical Industry Co., Ltd.)

[0201] In addition, the above ion scavenger uses a material obtained by subjecting it to fine pulverization treatment to adjust D95 to less than 5 μm.

[0202] <Production of the first adhesive layer>

[0203] After obtaining a composition by mixing the materials shown in Table 1 at the composition ratios shown in Table 1 (the values in Table 1 refer to the amount of non-volatile components), while applying a magnetic field on a PET (polyethylene terephthalate) film that has been subjected to a release treatment, coating is carried out, and organic solvents, etc. are dried by hot air at 70 °C for 5 minutes, whereby composition layers formed from the compositions containing each component are obtained respectively. The composition layers are coated to have a thickness of 3 to 4 μm after drying. Thereafter, light is irradiated on the composition layers respectively (UV irradiation: metal halide lamp, cumulative light amount: 1800 - 2300 mJ / cm 2 ), whereby the first adhesive layer in which conductive particles are dispersed is produced. The thickness here was measured using a contact type thickness gauge.

[0204] In addition, when the thickness of the layer formed from the first adhesive composition or the adhesive layer is less than the thickness (diameter) of the conductive particles, if the thickness of the layer is measured using a contact type thickness gauge, the thickness of the region where the conductive particles are present can be measured, reflecting the thickness of the conductive particles. Therefore, after producing an adhesive film having a two-layer structure in which the first adhesive layer and the second adhesive layer are laminated, by the aforementioned method (paragraph 0083), the thickness of the first adhesive layer at the separated portion between adjacent conductive particles was measured using a scanning electron microscope.

[0205] [Table 1]

[0206]

[0207] <Production of the second adhesive layer>

[0208] After obtaining a composition by mixing the materials shown in Table 2 at the composition ratios shown in Table 2 (the values in Table 2 refer to the amount of non-volatile components), coating is carried out on a PET (polyethylene terephthalate) film that has been subjected to a release treatment, and organic solvents, etc. are dried by hot air at 70 °C for 5 minutes, whereby the second composition layers formed from the compositions containing each component are produced respectively. The composition layers are coated to have a thickness of 8 to 9 μm after drying. The thickness here was measured using a contact type thickness gauge.

[0209] [Table 2]

[0210]

[0211] (Examples 1 to 4 and Comparative Examples 1 to 2)

[0212] [Production of adhesive film]

[0213] The adhesive films having the structures shown in Table 3 were produced using the above-produced first adhesive layer and second adhesive layer. For example, in the adhesive film of Example 1, the first adhesive layer formed from Composition P-1 was laminated on the second adhesive layer formed from Composition S-1 while applying a temperature of 50 to 60°C to obtain the adhesive film of Example 1. For the adhesive films of Examples 2 to 4 and Comparative Examples 1 to 2, the adhesive films having the structures shown in Table 3 were produced in the same manner as in Example 1.

[0214] For the adhesive films obtained in Examples 1 to 4 and Comparative Examples 1 to 2, the projected particle density was measured, and the result was about 18,000 particles / mm 2 .

[0215] [Evaluation of circuit connection structure]

[0216] <Production of circuit connection structure-1>

[0217] As the first circuit component, an IC chip (0.9 mm × 20.3 mm, thickness: 0.3 mm, bump electrode size: 70 μm × 12 μm, bump electrode pitch: 12 μm, bump electrode thickness: 9 μm) in which bump electrodes were arranged in two rows in a staggered manner was prepared. And, as the second circuit component, a component having a wiring pattern of Ti: 50 nm / Al: 400 nm (pattern width: 17 μm, electrode pitch: 7 μm) formed on the surface of a polyimide substrate (manufactured by DU PONT-TORAY CO., LTD., 200H) (38 mm × 28 mm, thickness: 0.05 mm) was prepared.

[0218] The circuit connection structures were produced using the adhesive films of Examples 1 to 4 and Comparative Examples 1 to 2. The adhesive films were cut into a width of 2.0 mm, and the adhesive films were disposed on the first circuit component so that the first adhesive layer was in contact with the first circuit component. Using a thermocompression bonding apparatus (BS-17U, manufactured by OHASHI ENGINEERING Co., Ltd.) composed of a stage including a ceramic heater and a tool (8 mm × 50 mm), at 70°C and 0.98 MPa (10 kgf / cm 2Under the conditions of heating and pressurizing for 2 seconds, the adhesive film was attached to the first circuit component, and the release film on the side of the adhesive film opposite to the first circuit component was peeled off. Next, after aligning the bump electrodes of the first circuit component with the wiring pattern of the second circuit component, an 8 mm × 45 mm heating tool was used, and with a 50-μm-thick Teflon (registered trademark) as a buffer material, heating and pressurizing were performed for 5 seconds under the connection conditions of 170°C and a pressure of 30 MPa in terms of the area of the bump electrodes, and the second adhesive layer of the adhesive film was attached to the second circuit component, thereby fabricating a circuit connection structure-1 respectively.

[0219] <Fabrication of Circuit Connection Structure-2>

[0220] As the first circuit component, an IC chip (0.9 mm × 20.3 mm, thickness: 0.3 mm, size of bump electrodes: 70 μm × 12 μm, pitch of bump electrodes: 12 μm, thickness of bump electrodes: 9 μm) in which bump electrodes were arranged in two staggered rows was prepared. And as the second circuit component, a component having a wiring pattern (pattern width: 19 μm, electrode pitch: 5 μm) of ITO formed on the surface of a glass substrate (manufactured by Corning Incorporated, #1737, 38 mm × 28 mm, thickness: 0.05 mm) was prepared.

[0221] The circuit connection structures were fabricated using the respective adhesive films of Examples 1 to 4 and Comparative Examples 1 to 2. The adhesive film was cut to a width of 2.0 mm, and the adhesive film was placed on the first circuit component so that the first adhesive layer was in contact with the first circuit component. Using a thermocompression bonding apparatus (BS-17U, manufactured by OHASHI ENGINEERING Co., Ltd.) composed of a stage including a ceramic heater and a tool (8 mm × 50 mm), heating and pressurizing were performed for 2 seconds under the conditions of 70°C and 0.98 MPa (10 kgf / cm 2 ) to attach the adhesive film to the first circuit component, and the release film on the side of the adhesive film opposite to the first circuit component was peeled off. Next, after aligning the bump electrodes of the first circuit component with the wiring pattern of the second circuit component, an 8 mm × 45 mm heating tool was used, and with a 50-μm-thick Teflon (registered trademark) as a buffer material, heating and pressurizing were performed for 5 seconds under the connection conditions of 170°C and a pressure of 30 MPa in terms of the area of the bump electrodes, and the second adhesive layer of the adhesive film was attached to the second circuit component, thereby fabricating a circuit connection structure-2 respectively.

[0222] (Evaluation of Connection Resistance)

[0223] For the fabricated circuit connection structure - 1, the initial connection resistance (on - resistance) was measured by the four - terminal test method. During the measurement, a multimeter MLR21 manufactured by ETAC was used. The potential difference was measured at 14 arbitrary points, and its average value was obtained. The average value of the potential difference was converted into a connection resistance value and evaluated according to the following criteria. The results are shown in Table 3.

[0224] A: The connection resistance value is less than 1.0 Ω

[0225] B: The connection resistance value is 1.0 Ω or more

[0226] (Evaluation of insulation resistance)

[0227] For the fabricated circuit connection structure - 2, after the high - temperature and high - humidity test (stored for 500 hours under the conditions of a temperature of 85 °C and a humidity of 85% RH), a voltage of 50 V was applied to the wiring diagram, and the insulation resistance between the circuit electrodes was measured at a total of 1440 points. This measurement was performed on 20 samples, and in all 20 samples, the number of samples with an insulation resistance value of 10 9 Ω or more was confirmed. Based on the obtained number, the insulation resistance was evaluated according to the following criteria. The results are shown in Table 3.

[0228] A: 20 insulation resistance values are 10 9 Ω or more

[0229] B: 19 - 17 insulation resistance values are 10 9 Ω or more

[0230] C: 16 - 13 insulation resistance values are 10 9 Ω or more

[0231] [Table 3]

[0232]

[0233] As shown in Table 3, for the adhesive films of Examples 1 - 4 containing the above - described cationic polymerizable compound, thermal cationic polymerization initiator, and ion scavenger, both the connection resistance and the insulation resistance were judged as A. On the other hand, for the adhesive film of Comparative Example 1 that does not contain an ion scavenger, the connection resistance was judged as A, but the insulation resistance was judged as C. Also, for the adhesive film of Comparative Example 2 that does not contain an ion scavenger and has an increased blending amount of the acrylate component, the insulation resistance was judged as B, but the connection resistance became high and was judged as B.

[0234] Symbol description

[0235] 1 - First adhesive layer, 2 - Second adhesive layer, 4 - Conductive particles, 5 - Adhesive component, 10 - Adhesive film for circuit connection (adhesive film), 11 - First circuit board, 12 - First electrode (circuit electrode), 13 - First circuit component, 14 - Second circuit board, 15 - Second electrode (bump electrode), 16 - Second circuit component, 17 - Circuit connection part.

Claims

1. An adhesive film for circuit connection, which is an adhesive film for circuit connection containing conductive particles, wherein, the adhesive film includes, in the thickness direction of the film, a region A containing a cationic polymerizable compound, a thermal cationic polymerization initiator, and an ion scavenger; the cationic polymerizable compound includes a compound having one or more ring-opening polymerizable cyclic ether groups in the molecule; the thermal cationic polymerization initiator includes an anilinium salt; the ion scavenger includes at least one metal compound selected from the group consisting of aluminum hydroxide, aluminum oxide, magnesium hydroxide, magnesium oxide, zirconium hydroxide, zirconium oxide, bismuth hydroxide, bismuth oxide, calcium hydroxide, calcium oxide, tin hydroxide, tin oxide, manganese hydroxide, manganese oxide, antimony hydroxide, antimony oxide, silicon hydroxide, silicon oxide, titanium hydroxide, and titanium oxide; the region A includes, in the thickness direction of the film: a region P, which is a cured product containing a cationic polymerizable compound, a thermal cationic polymerization initiator, an ion scavenger, a thermoplastic resin, and a photocurable resin component; and a region S, which is a cured product containing a cationic polymerizable compound, a thermal cationic polymerization initiator, an ion scavenger, and a thermoplastic resin, and not containing a photocurable resin component; the conductive particles are dispersed in the region P.

2. The adhesive film for circuit connection according to claim 1, wherein, the conductive particles have palladium plating.

3. The adhesive film for circuit connection according to claim 1 or 2, wherein, the anilinium salt is an anilinium salt having an anion containing boron as a constituent element.

4. An adhesive film for circuit connection, which includes: a first adhesive layer containing conductive particles, a cured product of a photocurable resin component, a first thermosetting resin component, and a thermoplastic resin; and a second adhesive layer provided on the first adhesive layer and containing a second thermosetting resin component and a thermoplastic resin, and not containing a cured product of a photocurable resin component, both the first adhesive layer and the second adhesive layer further contain an ion scavenger; both the first thermosetting resin component and the second thermosetting resin component contain a cationic polymerizable compound and a thermal cationic polymerization initiator; the cationic polymerizable compound includes a compound having one or more ring-opening polymerizable cyclic ether groups in the molecule; the thermal cationic polymerization initiator includes an anilinium salt; the ion scavenger includes at least one metal compound selected from the group consisting of aluminum hydroxide, aluminum oxide, magnesium hydroxide, magnesium oxide, zirconium hydroxide, zirconium oxide, bismuth hydroxide, bismuth oxide, calcium hydroxide, calcium oxide, tin hydroxide, tin oxide, manganese hydroxide, manganese oxide, antimony hydroxide, antimony oxide, silicon hydroxide, silicon oxide, titanium hydroxide, and titanium oxide.

5. The adhesive film for circuit connection according to claim 4, wherein, the conductive particles have palladium plating.

6. The adhesive film for circuit connection according to claim 4 or 5, wherein, the anilinium salt is an anilinium salt having an anion containing boron as a constituent element.

7. A method for manufacturing a circuit connection structure, comprising the following steps: interposing the adhesive film for circuit connection according to any one of claims 1 to 6 between a first circuit component having a first electrode and a second circuit component having a second electrode, and thermocompression bonding the first circuit component and the second circuit component to electrically connect the first electrode and the second electrode to each other.

8. The method for manufacturing a circuit connection structure according to claim 7, wherein one of the first circuit component and the second circuit component is an IC chip, and the other is a plastic substrate having an electrode containing Ti.

9. A circuit connection structure, comprising: a first circuit component having a first electrode; a second circuit component having a second electrode; and a circuit connection portion disposed between the first circuit component and the second circuit component to electrically connect the first electrode and the second electrode to each other, the circuit connection portion containing a cured product of the adhesive film for circuit connection according to any one of claims 1 to 6.

10. The circuit connection structure according to claim 9, wherein one of the first circuit component and the second circuit component is an IC chip, and the other is a plastic substrate having an electrode containing Ti.

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