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

Abstract

This adhesive agent film for circuit connection includes: an amide that has a lactam ring; a cationically polymerizable compound; a thermal polymerization initiator; and conductive particles. This connection structure comprises: a first circuit member that has a first electrode; a second circuit member that has a second electrode; and a connection section that is positioned between the first circuit member and the second circuit member, and electrically connects the first electrode and the second electrode to one another, wherein the connection section includes a cured product of the adhesive agent film for circuit connection.

Description

[Technical Field]

[0001] The present disclosure relates to an adhesive film for circuit connection, a connection structure, and a method for manufacturing the connection structure. [Background technology]

[0002] Circuit connection materials, which electrically connect electrodes in the direction of pressure by heating and pressurizing opposing circuits, such as circuit connection adhesive films (anisotropic conductive films) made of epoxy or acrylic adhesives with conductive particles dispersed in them, are widely used to electrically connect TCPs (Tape Carrier Packages) or COFs (Chip On Flex) that contain semiconductors that drive liquid crystal displays (LCDs) to LCD panels, or between TCPs or COFs and printed wiring boards.

[0003] Recently, even when semiconductors are directly mounted face-down on LCD panels or printed wiring boards, flip-chip mounting, which is advantageous for thin film and narrow pitch connections, is being adopted instead of the conventional wire bonding method, and here too adhesive films for circuit connection are used as the circuit connection material (see, for example, Patent Documents 1 to 4). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 59-120436 [Patent Document 2] Japanese Unexamined Patent Publication No. 60-191228 [Patent Document 3] Japanese Patent Application Publication No. 1-251787 [Patent Document 4] Japanese Patent Application Publication No. 7-90237 Summary of the Invention [Problem to be solved by the invention]

[0005] However, when an adhesive film for circuit connection is stored in a state where it is exposed to air, its adhesive strength decreases and it no longer has sufficient adhesion to circuit components.

[0006] Furthermore, adhesive films for circuit connection are required to suppress peeling from the electrode parts and to exhibit excellent resistance values ​​(connection resistance values) even when the circuit connection structure is exposed to a high-temperature, high-humidity environment (e.g., 85°C, 85% RH) for a long period of time (e.g., 250 hours) after the circuit components are connected.

[0007] Therefore, the present disclosure aims to provide an adhesive film for circuit connection that has excellent adhesion to circuit components even when stored in an air-exposed state, and that can ensure connection reliability between opposing electrodes even when the circuit connection structure is exposed to a high-temperature, high-humidity environment (e.g., 85°C, 85% RH) for a long period of time after connecting the circuit components, as well as a connection structure and a method for manufacturing the connection structure that uses the adhesive film for circuit connection. [Means for solving the problem]

[0008] One aspect of the present disclosure relates to an adhesive film for circuit connection, which contains an amide having a lactam ring, a cationically polymerizable compound, a thermal polymerization initiator, and conductive particles.

[0009] According to the above-mentioned adhesive film for circuit connection, which is one aspect of the present disclosure, the above-mentioned configuration allows, when the adhesive film for circuit connection is attached to a circuit component, sufficient adhesion between the circuit component and the adhesive film for circuit connection can be achieved, while also sufficiently reducing the connection resistance between opposing electrodes. In particular, by containing an amide having a lactam ring in the adhesive film for circuit connection, the adhesive film for circuit connection has excellent adhesion to circuit components even when stored in contact with air, and can ensure connection reliability between opposing electrodes even when the circuit connection structure is exposed to a high-temperature, high-humidity environment (e.g., 85°C, 85% RH) for an extended period of time after connecting the circuit components. The reason why the adhesive film for circuit connection contains an amide having a lactam ring and achieves the above-mentioned effect is presumably because the inclusion of an amide having a lactam ring in the adhesive film for circuit connection suppresses deterioration of the film surface, maintaining the state of the resin on the film surface in a state similar to that of the resin inside the film.

[0010] In the adhesive film for circuit connection, the lactam ring of the amide may have 3 to 12 carbon atoms.

[0011] In the above-mentioned adhesive film for circuit connection, the above-mentioned amide may include ε-caprolactam.

[0012] In the adhesive film for circuit connection, the cationically polymerizable compound may include at least one selected from the group consisting of oxetane compounds and alicyclic epoxy compounds.

[0013] In the adhesive film for circuit connection, the content of the amide by mass is A W The mass-based content of the thermal polymerization initiator is B W When A W / B W may be 0.001 to 0.2.

[0014] The adhesive film for circuit connection may comprise a first adhesive layer and a second adhesive layer laminated on the first adhesive layer, and the first adhesive layer may contain the amide, the cationic polymerizable compound, the thermal polymerization initiator, and the conductive particles.

[0015] Another aspect of the present disclosure relates to a connection structure comprising: a first circuit member having a first electrode; a second circuit member having a second electrode; and a connection portion disposed between the first circuit member and the second circuit member and electrically connecting the first electrode and the second electrode to each other, wherein the connection portion includes a cured product of the adhesive film for circuit connection.

[0016] Another aspect of the present disclosure relates to a method for manufacturing a connection structure, comprising the steps of interposing the above-mentioned adhesive film for circuit connection between a first circuit member having a first electrode and a second circuit member having a second electrode, and thermocompressing the first circuit member and the second circuit member to electrically connect the first electrode and the second electrode to each other. [Effects of the Invention]

[0017] According to the present disclosure, it is possible to provide an adhesive film for circuit connection that, when connecting circuit components together, has excellent adhesion to circuit components even when stored in an air-exposed state, and can ensure connection reliability between opposing electrodes even when the circuit connection structure is exposed to a high-temperature, high-humidity environment (e.g., 85°C, 85% RH) for a long period of time after connecting the circuit components together, as well as a connection structure and a method for manufacturing the connection structure using the adhesive film for circuit connection. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a schematic cross-sectional view showing one embodiment of an adhesive film for circuit connection. [Figure 2] 1 is a schematic cross-sectional view showing one embodiment of an adhesive film for circuit connection. [Figure 3] 1 is a schematic cross-sectional view showing one embodiment of a connection structure. [Figure 4] 4A to 4C are schematic cross-sectional views showing a method for manufacturing the connection structure of FIG. 3. DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, embodiments of the present disclosure will be described in detail, with reference to the drawings as needed. Note that the present disclosure is not limited to the following embodiments. Note that in this specification, a numerical range indicated using "to" indicates a range that includes the numerical values ​​before and after "to" as the minimum and maximum values, respectively. Furthermore, individually stated upper and lower limit values ​​can be arbitrarily combined. Furthermore, in this specification, "(meth)acrylate" means at least one of acrylate and its corresponding methacrylate. The same applies to other similar expressions such as "(meth)acryloyl." Furthermore, "(poly)" means both cases with and without the prefix "poly."

[0020] <Adhesive film for circuit connection> One embodiment of the present disclosure is an adhesive film for circuit connection that contains (a) an amide having a lactam ring, (b) a cationically polymerizable compound, (c) a thermal polymerization initiator, and (d) conductive particles. That is, one embodiment of the present disclosure is an adhesive film for circuit connection that contains an adhesive component that includes components (a) to (c) and conductive particles dispersed in the adhesive component.

[0021] (a) Amides with lactam rings By containing an amide having a lactam ring, the adhesive film for circuit connection can easily achieve excellent adhesion to circuit components when connecting circuit components together, even when stored in an air-exposed state, and can also easily ensure connection reliability between opposing electrodes even when the circuit connection structure is exposed to a high-temperature, high-humidity environment (e.g., 85°C, 85% RH) for a long period of time after connecting the circuit components together.

[0022] The lactam ring-containing amide may have 3 to 12 carbon atoms constituting the lactam ring. The number of carbon atoms constituting the lactam ring may be 3 to 10, 3 to 8, 3 to 7, or 3 to 6, from the viewpoint of more easily ensuring connection reliability between opposing electrodes even when the circuit connection structure is exposed to a high-temperature, high-humidity environment (e.g., 85°C, 85% RH) for a long period of time.

[0023] The amide having a lactam ring may have a functional group bonded to the lactam ring, such as a carboxy group, a carboxylate group, a hydroxy group, an alkoxy group, an alkyl group, an ester group, a sulfo group, a sulfonate group, a carbonyl group, an amino group, an amide group, a carboxamide group, a nitro group, a cyano group, or a halogen atom.

[0024] The amide having a lactam ring may comprise at least one member selected from the group consisting of 2-azetidinone, 2-pyrrolidinone (2-pyrrolidone), 2-piperidinone, ε-caprolactam, caprylolactam, and laurolactam (ω-laurinlactam), and may comprise ε-caprolactam, from the viewpoint of easily achieving excellent adhesion to circuit components even when stored in an air-exposed state when connecting circuit components together, and easily ensuring connection reliability between opposing electrodes even when the circuit connection structure is exposed to a high-temperature, high-humidity environment (e.g., 85°C, 85% RH) for an extended period of time after connecting the circuit components together. The content of ε-caprolactam may be 80% by mass or more, 90% by mass or more, or 95% by mass or more, or even 100% by mass, based on the total mass of the amide having a lactam ring.

[0025] The content of the amide having a lactam ring may be 0.001% by mass or more, 0.003% by mass or more, or 0.005% by mass or more, based on the total mass of the adhesive film for circuit connection, from the viewpoints of easily achieving excellent adhesion to circuit components even when stored in an air-exposed state when connecting circuit components, and easily ensuring connection reliability between opposing electrodes even when the circuit connection structure is exposed to a high-temperature, high-humidity environment (e.g., 85°C, 85% RH) for an extended period of time after connecting the circuit components. From the same viewpoint, the content of the amide having a lactam ring may be 2.0% by mass or less, 1.0% by mass or less, or 0.8% by mass or less, based on the total mass of the adhesive film for circuit connection. From these viewpoints, the content of the amide having a lactam ring may be 0.001 to 2.0% by mass, 0.003 to 1.0% by mass, or 0.005 to 0.8% by mass, based on the total mass of the adhesive film for circuit connection.

[0026] The content of the amide having a lactam ring may be 0.003% by mass or more, 0.006% by mass or more, or 0.009% by mass or more, based on the total mass of the adhesive film for circuit connection excluding conductive particles, from the viewpoints of easily achieving excellent adhesion to circuit components even when stored in an air-exposed state when connecting circuit components, and easily ensuring connection reliability between opposing electrodes even when the circuit connection structure is exposed to a high-temperature, high-humidity environment (e.g., 85°C, 85% RH) for an extended period of time after connecting the circuit components. From the same viewpoint, the content of the amide having a lactam ring may be 3.0% by mass or less, 2.0% by mass or less, or 1.0% by mass or less, based on the total mass of the adhesive film for circuit connection excluding conductive particles. From these viewpoints, the content of the amide having a lactam ring may be 0.003 to 3.0% by mass, 0.006 to 2.0% by mass, or 0.009 to 1.0% by mass, based on the total mass of the adhesive film for circuit connection excluding conductive particles.

[0027] The content of the amide having a lactam ring may be 0.005% by mass or more, 0.008% by mass or more, or 0.01% by mass or more, based on the total mass of the adhesive film for circuit connection excluding conductive particles and fillers, from the viewpoints of easily achieving excellent adhesion to circuit components even when stored in an air-exposed state when connecting circuit components, and easily ensuring connection reliability between opposing electrodes even when the circuit connection structure is exposed to a high-temperature, high-humidity environment (e.g., 85°C, 85% RH) for an extended period of time after connecting the circuit components. From the same viewpoint, the content of the amide having a lactam ring may be 4.0% by mass or less, 3.0% by mass or less, or 2.0% by mass or less, based on the total mass of the adhesive film for circuit connection excluding conductive particles and fillers. From these viewpoints, the content of the amide having a lactam ring may be 0.005 to 4.0% by mass, 0.008 to 3.0% by mass, or 0.01 to 2.0% by mass, based on the total mass of the adhesive film for circuit connection excluding conductive particles and fillers.

[0028] (b) Cationic polymerizable compound The cationically polymerizable compound is, for example, a compound that crosslinks by reacting with a thermal polymerization initiator due to heat. From the viewpoint of low-temperature fast curing (low-temperature short-time curing), the cationically polymerizable compound may contain at least one selected from the group consisting of an oxetane compound and an alicyclic epoxy compound, or may contain an oxetane compound and an alicyclic epoxy compound. One type of cationically polymerizable compound may be used alone, or two or more types may be used in combination.

[0029] The oxetane compound may be, for example, 2-ethylhexyloxetane, 3-hydroxymethyl-3-methyloxetane, 3-hydroxymethyl-3-ethyloxetane, 3-hydroxymethyl-3-propyloxetane, 3-hydroxymethyl-3-normal butyloxetane, 3-hydroxymethyl-3-phenyloxetane, 3-hydroxymethyl-3-benzyloxetane, 3-hydroxyethyl-3-methyloxetane, 3-hydroxyethyl-3-ethyloxetane, 3-hydroxyethyl-3-propyloxetane, 3-hydroxyethyl-3-phenyloxetane, 3-hydroxypropyl-3-methyloxetane, 3-hydroxypropyl-3-ethyloxetane, 3-hydroxypropyl-3-propyloxetane, 3-hydroxypropyl-3-phenyloxetane, 3-hydroxybutyl-3-methyloxetane, or 4,4'-bis[(3-ethyl-3-oxetanyl)methoxymethyl]biphenyl.

[0030] Examples of the alicyclic epoxy compound as the cationically polymerizable compound include 3',4'-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate (bi-7-oxabicyclo[4,1,0]heptane), 3,4-epoxycyclohexylmethyl (meth)acrylate, (3,3',4,4'-diepoxy)bicyclohexyl, hydrogenated bisphenol A epoxy resin, and hydrogenated bisphenol F epoxy resin.

[0031] The content of the cationically polymerizable compound may be 10% by mass or more, 15% by mass or more, or 20% by mass or more, based on the total mass of the adhesive film for circuit connection, from the viewpoint of ensuring the curability of the adhesive film for circuit connection. The content of the cationically polymerizable compound may be 50% by mass or less, 40% by mass or less, or 30% by mass or less, based on the total mass of the adhesive film for circuit connection, from the viewpoint of ensuring the formability of the adhesive film for circuit connection. From these viewpoints, the content of the cationically polymerizable compound may be 10 to 50% by mass, 15 to 40% by mass, or 20 to 30% by mass, based on the total mass of the adhesive film for circuit connection.

[0032] When the cationically polymerizable compound contains an oxetane compound and an alicyclic epoxy compound, the ratio of the mass-based content of the oxetane compound to the mass-based content of the alicyclic epoxy compound (mass-based content of oxetane compound / mass-based content of alicyclic epoxy compound) may be 0.2 to 5.0, 0.5 to 4.0, 1.0 to 3.0, or 1.5 to 2.5, from the viewpoint of improving the reactivity of the oxetane compound.

[0033] (c) Thermal polymerization initiator The thermal polymerization initiator is a compound that generates an acid or the like when heated to initiate polymerization, and may be a compound composed of a cation and an anion. Examples of the thermal polymerization initiator include SbF6 - , PF6 - , P.F. X (CF3) 6-X - (where X is an integer between 1 and 5), BF4 - , B(C6F5)4 - , RSO3 - (wherein R is an alkyl group having 1 to 3 carbon atoms, or a substituted or unsubstituted aryl group), C(SO2CF3)3 - and onium salts such as sulfonium salts, phosphonium salts, ammonium salts, diazonium salts, iodonium salts, and anilinium salts having anions such as those listed above. These may be used alone or in combination of two or more.

[0034] From the viewpoints of low-temperature curing property and storage stability, the onium salt as the thermal polymerization initiator may include an anilinium salt, and may include at least one selected from the group consisting of N-alkylanilinium salts, N-benzylanilinium salts, N,N-dialkylanilinium salts, and N,N,N-trialkylanilinium salts. In these anilinium salts, the hydrocarbon group bonded to the nitrogen atom may have a substituent.

[0035] Examples of the anilinium salt include N-benzyl-N,N-dimethylanilinium tetrakispentafluorophenylborate, N-(4-nitrobenzyl)-N,N-dimethylanilinium tetrakispentafluorophenylborate, N-(4-methoxybenzyl)-N,N-dimethylanilinium tetrakispentafluorophenylborate, N-(α-phenylbenzyl)-N,N-dimethylanilinium tetrakispentafluorophenylborate, N-(α-methylbenzyl)-N,N-dimethylanilinium tetrakispentafluorophenylborate, N-(1-naphthylmethyl)-N,N-dimethylanilinium tetrakispentafluorophenylborate, and N-cinnamyl-N,N-dimethylanilinium tetrakispentafluorophenylborate.

[0036] The anilinium salt as the thermal polymerization initiator may have an N-benzylanilinium derivative structure represented by the following formula (1), from the viewpoint that the polymerization initiation temperature can be set with a high degree of freedom by selecting the thermal polymerization initiator. [ka] [In formula (1), R 1 , R 2 , R 3 , R 8 , R 9 and R 10 each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, a nitro group, an amino group, an alkylamino group, a cyano group, an alkoxycarbonyl group, or a carbonyl group; R 4 and R 5 each independently represents a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or a halogen atom; R 6 and R 7 each independently represents a halogen atom or an alkyl group having 1 to 3 carbon atoms; X - is SbF6 - , PF6 - , P.F. X (CF3) 6-X - (where X is an integer between 1 and 5), BF4- , B(C6F5)4 - , RSO3 - (R represents an alkyl group or aryl group having 1 to 3 carbon atoms, which may have a substituent), C(SO2CF3)3 - ]

[0037] Commercially available anilinium salts that satisfy the above formula (1) include, for example, K-PURE CXC-1612, K-PURE CXC-1733, K-PURE CXC-1738, K-PURE TAG-2678, K-PURE CXC-1614, K-PURE TAG-2689, K-PURE TAG-2690, K-PURE TAG-2700, K-PURE CXC-1802-60, and K-PURE CXC-1821 (manufactured by King Industries).

[0038] The content of the thermal polymerization initiator may be 0.5% by mass or more, 1.0% by mass or more, or 3.0% by mass or more, based on the total mass of the adhesive film for circuit connection, from the viewpoint of sufficiently promoting the curing reaction. The content of the thermal polymerization initiator may be 20% by mass or less, 15% by mass or less, or 10% by mass or less, based on the total mass of the adhesive film for circuit connection, from the viewpoint of improving the physical properties of the cured product. From these viewpoints, the content of the thermal polymerization initiator may be 0.5 to 20% by mass, 1.0 to 15% by mass, or 3.0 to 10% by mass, based on the total mass of the adhesive film for circuit connection.

[0039] The mass content of amide having a lactam ring is A W The mass-based content of the thermal polymerization initiator is B W (A W When the units are the same as those of A W and B W Ratio to (A W / B W ) may be 0.001 or more, 0.01 or more, or 0.05 or more, from the viewpoint of easily obtaining superior adhesion to circuit components. W and B W Ratio to (A W / B W) may be 0.2 or less, 0.15 or less, or 0.1 or less, from the viewpoint of suppressing an increase in the mounting temperature. W and B W Ratio to (A W / B W ) may be 0.001 to 0.2, 0.01 to 0.15, or 0.05 to 0.1.

[0040] (d) Conductive particles The conductive particles are not particularly limited as long as they are conductive particles, and may be metal particles made of metals such as gold, silver, palladium, nickel, copper, or solder, or conductive carbon particles made of conductive carbon. The conductive particles may also be coated conductive particles having a core containing non-conductive glass, ceramic, plastic (e.g., polystyrene), or the like, and a coating layer containing the above metal or conductive carbon that coats the core. Among these, the conductive particles may include at least one selected from the group consisting of metal particles and coated conductive particles formed of heat-fusible metals, and may include coated conductive particles. Coated conductive particles are easily deformed by heating and / or pressure, and therefore, when electrodes are electrically connected, the contact area between the electrodes and the conductive particles can be increased, thereby further improving the conductivity between the electrodes.

[0041] The conductive particles may have an average particle size of 1.0 μm or more, 2.0 μm or more, or 2.5 μm or more, from the viewpoint of excellent dispersibility and conductivity. The conductive particles may have an average particle size of 6.0 μm or less, 5.5 μm or less, or 5.0 μm or less, from the viewpoint of ensuring insulation between adjacent electrodes. From these viewpoints, the conductive particles may have an average particle size of 1.0 to 6.0 μm, 2.0 to 5.5 μm, or 2.5 to 5.0 μm.

[0042] The average particle size of the conductive particles is determined by measuring the particle size of 300 conductive particles contained in the adhesive film for circuit connection by observation with a scanning electron microscope (SEM), and taking the average value of the particle sizes of 300 conductive particles. If the conductive particles are not spherical, the particle size of the conductive particles is taken to be the diameter of the circle circumscribing the conductive particles in the SEM observation image.

[0043] The conductive particles may be uniformly dispersed in the adhesive film for circuit connection. From the viewpoint of obtaining a stable connection resistance, the particle density of the conductive particles in the adhesive film for circuit connection is set to 100 particles / mm 2 More than 1000 pieces / mm 2 or more than 3000 pieces / mm 2 The particle density of the conductive particles in the adhesive film for circuit connection may be 100,000 particles / mm or more from the viewpoint of ensuring insulation between adjacent electrodes. 2 Below, 50000 pieces / mm 2 or less than 30,000 pieces / mm 2 From these viewpoints, the particle density of the conductive particles in the adhesive film for circuit connection may be 100 to 100,000 particles / mm 2 , 1000~50000 pieces / mm 2 , or 3000 to 30,000 pieces / mm 2 It may be.

[0044] The content of the conductive particles may be 10% by mass or more, 20% by mass or more, or 30% by mass or more, based on the total mass of the adhesive film for circuit connection, and 60% by mass or less, 50% by mass or less, or 40% by mass or less, based on the total mass of the adhesive film for circuit connection.

[0045] (Other ingredients) The adhesive film for circuit connection may further contain other components in addition to the above components (a) to (d), such as (e) a thermoplastic resin, (f) a coupling agent, and (g) a filler.

[0046] (e) Thermoplastic resin By including a thermoplastic resin, the adhesive film for circuit connection can be easily formed into a film. Examples of thermoplastic resins include phenoxy resin, polyester resin, polyamide resin, polyurethane resin, polyester urethane resin, acrylic rubber, epoxy resin (solid at 25° C.), etc. These may be used alone or in combination of two or more.

[0047] The weight average molecular weight (Mw) of the thermoplastic resin may be, for example, 5,000 to 200,000, 10,000 to 100,000, 20,000 to 80,000, or 40,000 to 60,000. The weight average molecular weight of the thermoplastic resin refers to a value measured by gel permeation chromatography (GPC) and converted using a calibration curve based on standard polystyrene.

[0048] The content of the thermoplastic resin may be 1.0% by mass or more, 5.0% by mass or more, 10% by mass or more, or 15% by mass or more, based on the total mass of the adhesive film for circuit connection. The content of the thermoplastic resin may be 50% by mass or less, 40% by mass or less, 30% by mass or less, or 20% by mass or less, based on the total mass of the adhesive film for circuit connection. The content of the thermoplastic resin may be 1.0 to 50% by mass, 5.0 to 40% by mass, 10 to 30% by mass, or 15 to 20% by mass, based on the total mass of the adhesive film for circuit connection.

[0049] (f) Coupling agent The adhesive film for circuit connection can further improve its adhesiveness by containing a coupling agent. The coupling agent may be, for example, a silane coupling agent. Examples of coupling agents include vinyltrimethoxysilane, vinyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-(meth)acryloxypropylmethyldimethoxysilane, 3-(meth)acryloxypropyltrimethoxysilane, 3-(meth)acryloxypropylmethyldiethoxysilane, 3-(meth)acryloxypropyltriethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, and condensates thereof. These may be used alone or in combination of two or more.

[0050] The content of the coupling agent may be 0.1% by mass or more, 0.5% by mass or more, 1.0% by mass or more, or 1.5% by mass or more, based on the total mass of the adhesive film for circuit connection. The content of the coupling agent may be 10% by mass or less, 8.0% by mass or less, 5.0% by mass or less, or 3.0% by mass or less, based on the total mass of the adhesive film for circuit connection. The content of the coupling agent may be 0.1 to 10% by mass, 0.5 to 8.0% by mass, 1.0 to 5.0% by mass, or 1.5 to 3.0% by mass, based on the total mass of the adhesive film for circuit connection.

[0051] (g) Filling material The adhesive film for circuit connection can further improve connection reliability by containing a filler. Examples of the filler include non-conductive fillers (e.g., non-conductive particles). The filler may be either an inorganic filler or an organic filler.

[0052] Examples of inorganic fillers include metal oxide particles such as silica particles, alumina particles, silica-alumina particles, titania particles, and zirconia particles; metal nitride particles, etc. These may be used alone or in combination of two or more.

[0053] Examples of organic fillers include silicone particles, methacrylate-butadiene-styrene particles, acrylic-silicone particles, polyamide particles, polyimide particles, etc. These may be used alone or in combination of two or more.

[0054] The filler may contain an inorganic filler or silica particles from the viewpoint of improving film formability and reliability of the connection structure. The silica particles may be crystalline silica particles or amorphous silica particles, and these silica particles may be synthetic products. The silica may be synthesized by a dry method or a wet method. The silica particles may contain at least one type selected from the group consisting of fumed silica particles and sol-gel silica particles.

[0055] The silica particles may be surface-treated silica particles from the viewpoint of excellent dispersibility in the adhesive component. The surface-treated silica particles may be, for example, silica particles surface-treated with a silane compound such as an alkoxysilane compound, a disilazane compound, or a siloxane compound, or may be silica particles surface-treated with a silane coupling agent. The surface-treated silica particles are, for example, silica particles whose surface hydroxyl groups are hydrophobized with a silane compound or a silane coupling agent.

[0056] Examples of the alkoxysilane compound include methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, dimethoxydiphenylsilane, tetraethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, octyltriethoxysilane, decyltrimethoxysilane, 1,6-bis(trimethoxysilyl)hexane, and 3,3,3-trifluoropropyltrimethoxysilane.

[0057] Examples of the disilazane compound include 1,1,1,3,3,3-hexamethyldisilazane, 1,3-diphenyltetramethyldisilazane, 1,3-bis(3,3,3-trifluoropropyl)-1,1,3,3-tetramethyldisilazane, and 1,3-divinyl-1,1,3,3-tetramethyldisilazane.

[0058] Examples of siloxane compounds include tetradecamethylcycloheptasiloxane, decamethylcyclopentasiloxane, hexaphenylcyclosiloxane, octadecamethylcyclononasiloxane, hexadecamethylcyclooctasiloxane, dodecamethylcyclohexasiloxane, octaphenylcyclotetrasiloxane, hexamethylcyclotrisiloxane, heptaphenyldisiloxane, tetradecamethylhexasiloxane, dodecamethylpentasiloxane, hexamethyicyclohex ... Tyldisiloxane, decamethyltetrasiloxane, hexamethoxydisiloxane, octamethyltrisiloxane, octamethylcyclotetrasiloxane, 1,3-vinyltetramethyldisiloxane, 2,4,6-trimethyl-2,4,6-trivinylcyclotrisiloxane, 1,3-dimethoxy-1,1,3,3-tetraphenyldisiloxane, 1,1,3,3-tetramethyl-1,3-diphenyldisiloxane, 1,3-dimethyl-1,3-diphenyl-1,3- Divinyldisiloxane, 2,4,6,8-tetramethyl-2,4,6,8-tetravinylcyclotetrasiloxane, 1,1,1,3,5,5,5-heptamethyl-3-(3-glycidyloxypropyl)trisiloxane, 1,3,5-tris(3,3,3-trifluoropropyl)-1,3,5-trimethylcyclotrisiloxane, 1,1,1,3,5,5,5-heptamethyl-3-[(trimethylsilyl)oxy]trisiloxane, 1,3-bis[2-(7 -oxabicyclo[4.1.0]heptan-3-yl)ethyl]-1,1,3,3-tetramethyldisiloxane, 1,1,1,5,5,5-hexamethyl-3-[(trimethylsilyl)oxy]-3-vinyltrisiloxane, 3-[[dimethyl(vinyl)silyl]oxy]-1,1,5,5-tetramethyl-3-phenyl-1,5-vinyltrisiloxane, octavinyloctasilsesquioxane, and octaphenyloctasilasilsesquioxane.

[0059] Silane coupling agents include vinyltrimethoxysilane, vinyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, N-2-(amino)-2-(methyl ... N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N-(1,3-dimethyl-butylidene)propylamine, N-phenyl-3-aminopropyltrimethoxysilane, tris-(trimethoxysilylpropyl)isocyanurate, 3-ureidopropyltrialkoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, 3-trimethoxysilylpropylsuccinic anhydride, and the like.

[0060] Silica particles that have been surface-treated with a silane compound or a silane coupling agent may be further surface-treated with a silane compound such as 3-methacryloxypropyltrimethoxysilane, vinyltrimethoxysilane, or trimethoxyphenylsilane to further hydrophobize the hydroxyl group residues on the surface of the silica particles.

[0061] From the viewpoint of easily controlling the fluidity when the circuit connection adhesive film is pressed, and of improving the mechanical properties and water resistance of the connection structure after pressing, the surface-treated silica particles may contain at least one selected from the group consisting of a reaction product (hydrolysis product) of silica and trimethoxyoctylsilane, a reaction product of silica and dimethylsiloxane, a reaction product of silicon dioxide or silica and dichloro(dimethyl)silane, a reaction product (hydrolysis product) of silica and bis(trimethylsilyl)amine, and a reaction product of silica and hexamethyldisilazane, or may contain at least one selected from the group consisting of a reaction product of silica and trimethoxyoctylsilane, and a reaction product of silica and bis(trimethylsilyl)amine.

[0062] The filler content may be 0.1% by mass or more, 1.0% by mass or more, 5.0% by mass or more, or 10% by mass or more, based on the total mass of the adhesive film for circuit connection. The filler content may be 50% by mass or less, 40% by mass or less, 30% by mass or less, or 20% by mass or less, based on the total mass of the adhesive film for circuit connection. The filler content may be 0.1 to 50% by mass, 1.0 to 40% by mass, 5.0 to 30% by mass, or 10 to 20% by mass, based on the total mass of the adhesive film for circuit connection.

[0063] An adhesive film for circuit connection according to one embodiment comprises a layer (first adhesive layer) made of an adhesive composition containing an adhesive component comprising at least the above-described components (a) to (c) and conductive particles (d) dispersed in the adhesive component. The adhesive film for circuit connection may have a single-layer structure made of the first adhesive layer, or may have a multilayer structure comprising the first adhesive layer and a layer other than the first adhesive layer. When the adhesive film for circuit connection has a multilayer structure, the contents of the above-described components (a) to (g) may be within the ranges mentioned above, based on the total mass of each layer.

[0064] The adhesive film for circuit connection may be provided on a substrate (e.g., a PET film) etc. The adhesive film for circuit connection with a substrate can be produced, for example, by applying an adhesive composition containing at least the above-mentioned (a) to (d) onto the substrate using a knife coater, roll coater, applicator, comma coater, die coater or the like.

[0065] Fig. 1 is a schematic cross-sectional view showing an adhesive film for circuit connection according to one embodiment. As shown in Fig. 1, in one embodiment, the adhesive film for circuit connection 1 is composed of a single layer made of an adhesive component 2 and conductive particles 3 dispersed in the adhesive component 2. In one embodiment, the adhesive component 2 contains at least the above-mentioned components (a) to (c), and the conductive particles 3 may be the above-mentioned component (d). The adhesive film for circuit connection 1 may be in an uncured state or in a partially cured state.

[0066] The thickness of the adhesive film for circuit connection 1 may be, for example, 5 μm or more or 10 μm or more, and may be 30 μm or less or 20 μm or less. The thickness of the adhesive film for circuit connection 1 may be 5 to 30 μm or 10 to 20 μm.

[0067] In one embodiment, the adhesive film for circuit connection may have a multilayer structure having two or more layers. For example, as shown in FIG. 2, the adhesive film for circuit connection 1 may have a two-layer structure including a layer 1A containing conductive particles 3A (a first adhesive layer consisting of adhesive component 2A and conductive particles 3A dispersed in adhesive component 2A) and a layer 1B not containing conductive particles (a second adhesive layer consisting of adhesive component 2B). In this case, the first adhesive layer 1A may be a layer consisting of an adhesive composition (first adhesive composition) containing an adhesive component containing at least the above-described components (a) to (c) and the above-described conductive particles (d), and the second adhesive layer 1B may be a layer consisting of an adhesive composition (second adhesive composition) containing the above-described components (a) to (c) and (e) to (g). The types, contents, etc. of the components contained in the second adhesive layer 1B may be the same as or different from those in the first adhesive layer 1A. The first adhesive layer 1A and the second adhesive layer 1B of the adhesive film for circuit connection 1 may each be in an uncured state or in a partially cured state.

[0068] The thickness of the first adhesive layer 1A may be, for example, 3 μm or more or 5 μm or more, and 15 μm or less or 10 μm or less. The thickness of the first adhesive layer 1A may be 3 to 15 μm or 5 to 10 μm. The thickness of the second adhesive layer 1B may be, for example, 5 μm or more or 10 μm or more, and 20 μm or less or 15 μm or less. The thickness of the second adhesive layer 1B may be 5 to 20 μm or 10 to 15 μm. The ratio of the thickness of the first adhesive layer 1A to the thickness of the second adhesive layer 1B (thickness of the first adhesive layer 1A / thickness of the second adhesive layer 1B) may be 0.1 or more or 0.3 or more, and 1.0 or less or 0.5 or less. The ratio of the thickness of the first adhesive layer 1A to the thickness of the second adhesive layer 1B (thickness of the first adhesive layer 1A / thickness of the second adhesive layer 1B) may be 0.1 to 1.0 or 0.3 to 0.5.

[0069] The adhesive film for circuit connection according to one embodiment may have anisotropic conductivity. That is, the adhesive film for circuit connection may be an anisotropic conductive film. The adhesive film for circuit connection may also be a conductive adhesive film that does not have anisotropic conductivity.

[0070] <Connection structure> Another embodiment of the present disclosure is a connection structure comprising: a first circuit member having a first electrode; a second circuit member having a second electrode; and a connection portion disposed between the first circuit member and the second circuit member and electrically connecting the first electrode and the second electrode to each other, wherein the connection portion comprises a cured product of the adhesive film for circuit connection.

[0071] Fig. 3 is a schematic cross-sectional view showing one embodiment of a connection structure. As shown in Fig. 3, a structure 10 includes a first circuit member 4 and a second circuit member 5 facing each other, and a connection portion 6 between the first circuit member 4 and the second circuit member 5, connecting the first circuit member 4 and the second circuit member 5.

[0072] The first circuit member 4 includes a first circuit board 41 and a first electrode 42 formed on a main surface 41a of the first circuit board 41. The second circuit member 5 includes a second circuit board 51 and a second electrode 52 formed on a main surface 51a of the second circuit board 51.

[0073] There are no particular limitations on the first circuit member 4 and the second circuit member 5, as long as they are members on which electrodes that require electrical connection are formed. Examples of members on which electrodes are formed (circuit members, etc.) include inorganic substrates such as semiconductors, glass, and ceramics; polyimide substrates such as TCP, FPC, and COF; substrates on which electrodes are formed on films such as polycarbonate, polyester, and polyethersulfone; and printed wiring boards, and a combination of these may also be used.

[0074] The connecting portion 6 includes a cured product of the adhesive film for circuit connection 1, and contains an insulating material 7 that is a cured product of the adhesive component 2, and conductive particles 3. The conductive particles 3 may be disposed not only between the opposing first electrode 42 and second electrode 52, but also between the main surface 41 a of the first circuit board 41 and the main surface 51 a of the second circuit board 51. In the structure 30, the first electrode 42 and the second electrode 52 are electrically connected via the conductive particles 3. That is, the conductive particles 3 are in contact with both the first electrode 42 and the second electrode 52.

[0075] In the structure 10, as described above, the opposing first electrode 42 and second electrode 52 are electrically connected via the conductive particles 3. This sufficiently reduces the connection resistance between the first electrode 42 and the second electrode 52. This allows the current to flow smoothly between the first electrode 42 and the second electrode 52, allowing the first circuit member 4 and the second circuit member 5 to fully exhibit their functions.

[0076] <Method of manufacturing the connection structure> Another embodiment of the present disclosure is a method for manufacturing a connection structure, comprising the steps of interposing the above-mentioned adhesive film for circuit connection between a first circuit member having a first electrode and a second circuit member having a second electrode, and thermocompression bonding the first circuit member and the second circuit member to electrically connect the first electrode and the second electrode to each other.

[0077] 4 is a schematic cross-sectional view showing one embodiment of a method for producing a connection structure. As shown in FIG. 4(a), first, a first circuit member 4 and an adhesive film for circuit connection 1 are prepared. Next, the adhesive film for circuit connection 1 is placed on the main surface 41a of the first circuit member 4. When the adhesive film for circuit connection 1 is laminated on a substrate (not shown), the laminate is placed on the first circuit member 4 with the adhesive film for circuit connection 1 side of the substrate facing the first circuit member 4. When the adhesive film for circuit connection 1 has a first adhesive layer 1A and a second adhesive layer 1B as shown in FIG. 2, the first adhesive layer side may be placed in contact with the main surface 41a of the first circuit member 4 to increase the number of conductive particles captured between the opposing electrodes.

[0078] Then, the adhesive film for circuit connection 1 is pressed in the directions of arrows A and B in Figure 4(a) to temporarily connect the adhesive film for circuit connection 1 to the first circuit member 4 (see Figure 4(b)). At this time, heating may be performed together with the pressing.

[0079] 4(c), a second circuit member 5 is further placed on the adhesive film 1 for circuit connection placed on the first circuit member 4, with the second electrode 52 facing the first circuit member 4 (i.e., the first electrode 42 and the second electrode 52 are placed opposite each other, with the adhesive film 1 for circuit connection interposed between the first circuit member 4 and the second circuit member 5). If the adhesive film 1 for circuit connection is laminated on a substrate (not shown), the substrate is peeled off and then the second circuit member 5 is placed on the adhesive film 1 for circuit connection.

[0080] The adhesive film 1 for circuit connection is then thermocompressed in the directions of arrows A and B in Figure 4(c). This hardens the adhesive film 1 for circuit connection, and completes the electrical connection between the first electrode 42 and the second electrode 52. As a result, a structure 10 as shown in Figure 3 is obtained.

[0081] In the structure 10 obtained as described above, it is possible to bring the conductive particles 3 into contact with both the opposing first electrode 42 and second electrode 52, and the connection resistance between the first electrode 42 and the second electrode 52 can be sufficiently reduced.

[0082] By applying pressure to the adhesive film for circuit connection 1 while heating it, the adhesive component 2 hardens to form an insulating material 7 while the distance between the first electrode 42 and the second electrode 52 is kept sufficiently small, and the first circuit member 4 and the second circuit member 5 are firmly connected via the connecting portion 6. Furthermore, in the structure 10, the adhesive strength remains sufficiently high for a long period of time. Therefore, in the structure 10, changes in the distance between the first electrode 42 and the second electrode 52 over time are sufficiently suppressed, and the long-term reliability of the electrical properties between the first electrode 42 and the second electrode 52 is excellent. [Example]

[0083] The present disclosure will be specifically described below with reference to examples, but the present disclosure is not limited to the following examples.

[0084] <Preparation of conductive particles> A nickel layer was formed on the surface of cross-linked polystyrene particles to a thickness of 0.15 μm, yielding conductive particles with an average particle size of 3.3 μm, a maximum particle size of 3.5 μm, and a specific gravity of 2.7.

[0085] <Preparation of adhesive film for circuit connection> A first adhesive composition for forming a first adhesive layer and a second adhesive composition for forming a second adhesive layer were prepared by mixing the components in the amounts (unit: parts by mass) shown in Tables 1 and 2. Details of each component in Tables 1 and 2 are as follows, and the amount of each component in the tables represents the amount of non-volatile content. Cationic polymerizable compounds B1: Bi-7-oxabicyclo[4,1,0]heptane (trade name: Celloxide 8010, manufactured by Daicel Chemical Industries, Ltd.) B2: 4,4'-Bis[(3-ethyl-3-oxetanyl)methyl]biphenyl (trade name: OXBP, manufactured by Ube Industries, Ltd.) · Thermal polymerization initiator C1: Quaternary ammonium salt (trade name: K-PURE CXC-1821, manufactured by King Industries) · Conductive particles D1: Conductive particles prepared as described above · Thermoplastic resin E1: P-1 (fluorene-type phenoxy resin) E2: Bisphenol A solid epoxy resin (trade name: jER1010, manufactured by Mitsubishi Chemical Corporation) · Coupling agent F1: γ-Glycidoxypropyltrimethoxysilane (trade name: KBM-403, manufactured by Shin-Etsu Chemical Co., Ltd.) · Filler G1: Surface-treated silica particles (hydrolysis product of silica and bis(trimethylsilyl)amine) G2: Surface-treated silica fine particles (hydrolysis product of trimethoxyoctylsilane and silica, trade name: Aerosil R805, manufactured by Evonik Industries AG, diluted with an organic solvent to a non-volatile content of 10% by mass)

[0086] <Synthesis of P-1> In a 3000 mL three-neck flask equipped with a Dimroth condenser, a calcium chloride tube, and a Teflon stir bar connected to a stirring motor, 45 g of 4,4'-(9-fluorenylidene)-diphenol (Sigma-Aldrich Japan Co., Ltd.) and 50 g of 3,3',5,5'-tetramethylbiphenol diglycidyl ether (YX-4000H, Mitsubishi Chemical Corporation) were dissolved in 1000 mL of N-methylpyrrolidone to form a reaction solution. 21 g of potassium carbonate was added to the reaction solution, and the mixture was stirred for 3 hours while heated to 110°C using a mantle heater. The stirred reaction solution was added dropwise to a beaker containing 1000 mL of methanol, and the resulting precipitate was collected by suction filtration. The collected precipitate was washed three times with 300 mL of methanol to obtain 75 g of phenoxy resin P-1. The molecular weight of the obtained phenoxy resin P-1 was measured using a high-performance liquid chromatograph (Tosoh Corporation, GP8020, column: Hitachi Chemical Co., Ltd., Gelpack GL-A150S and GLA160S, eluent: tetrahydrofuran, flow rate: 1.0 mL / min), and the polystyrene equivalent values ​​were Mn=15769, Mw=38045, and Mw / Mn=2.413.

[0087] The second adhesive composition was applied onto a substrate (PET film) to form a second adhesive layer on the substrate. Furthermore, the first adhesive composition was applied onto the second adhesive layer to form a first adhesive layer, thereby producing an adhesive film for circuit connection in which the first adhesive layer, second adhesive layer, and substrate were laminated in this order. The thickness of the first adhesive layer in each of the adhesive films for circuit connection in Examples 1 to 13 and Comparative Examples 1 and 2 was 7 μm, and the thickness of the second adhesive layer was 11 μm.

[0088] <Evaluation of adhesiveness> An AlNd (100 nm) / Mo (50 nm) / ITO (100 nm) wiring pattern (pattern width: 19 μm, inter-electrode space: 5 μm) was formed on the surface of an alkali-free glass substrate (OA-11, manufactured by Nippon Electric Glass Co., Ltd., 38 mm × 28 mm, thickness: 0.3 mm) to prepare evaluation members. Each circuit-connecting adhesive film (1.5 mm × 25 mm) of Examples 1 to 13 and Comparative Examples 1 and 2 was placed on the evaluation member so that the first adhesive layer was in contact with the evaluation member. Using a thermocompression bonding device (BS-17U, manufactured by Ohashi Manufacturing Co., Ltd., a thermocompression bonding device equipped with a stage made of a ceramic heater and a tool (8 mm × 50 mm)), the evaluation members were heated at 70°C and 0.98 MPa (10 kgf / cm 2 ) for 2 seconds under conditions of 0.15°C and 0.25°C, and the circuit-connecting adhesive film was attached to the evaluation component. After the substrate was peeled from the circuit-connecting adhesive film, the interface between the evaluation component and the circuit-connecting adhesive film was observed using an FPD / LSI inspection microscope (Nikon Instech Corporation, ECLIPSE L300ND) from the side of the evaluation component where the circuit-connecting adhesive film was not attached, to confirm the adhesion of the circuit-connecting adhesive film. The circuit-connecting adhesive film attached to the evaluation component was either immediately after the circuit-connecting adhesive film was produced, or after the circuit-connecting adhesive film was produced, the substrate was peeled off, and the film was stored for 96 hours at 25°C, 60% RH, and under fluorescent lighting, with the first adhesive layer exposed to air. A rating of "○" was given for cases where no lifting was observed at the interface between the evaluation component and the circuit-connecting adhesive film, and a rating of "×" was given for cases where lifting was observed. The results are shown in Tables 1 and 2.

[0089] <Fabrication of connection structure> The first circuit component was an alkali-free glass substrate (OA-11, manufactured by Nippon Electric Glass Co., Ltd., dimensions: 38 mm × 28 mm, thickness: 0.3 mm) with a wiring pattern of AlNd (100 nm) / Mo (50 nm) / ITO (100 nm) (pattern width: 19 μm, inter-electrode spacing: 5 μm).The second circuit component was an IC chip (dimensions: 0.9 mm × 20.3 mm, thickness: 0.3 mm, bump electrode size: 70 μm × 12 μm, inter-electrode spacing: 12 μm, bump electrode thickness: 8 μm) with bump electrodes arranged in two staggered rows.

[0090] Connection structures were produced using the adhesive films for circuit connection of Examples 1 to 13 and Comparative Examples 1 and 2. The first adhesive layer of the adhesive film for circuit connection was placed on a first circuit member. Using a thermocompression bonding device (LD-06, manufactured by Ohashi Manufacturing Co., Ltd.) consisting of a stage made of a ceramic heater and a tool (8 mm x 50 mm), the connection structures were subjected to a pressure of 50°C and 0.98 MPa (10 kgf / cm 2 ) for 2 seconds to bond the adhesive film for circuit connection to the first circuit member. Next, the release film on the side of the adhesive film for circuit connection opposite the first circuit member was peeled off, and the bump electrodes of the first circuit member were aligned with the circuit electrodes of the second circuit member. Using an 8 mm x 45 mm heat tool, the adhesive film was heated and pressed at 60 MPa for 5 seconds at the mounting temperature shown in Tables 1 and 2 on a base heated to 80°C, via a 50 μm thick PTFE sheet as a buffer, to bond the second adhesive layer of the adhesive film for circuit connection to the second circuit member, thereby producing a connection structure. The temperature indicates the maximum temperature actually measured for the adhesive film for circuit connection, and the pressure indicates a value calculated relative to the total area of ​​the surface of the bump electrodes of the second circuit member facing the first circuit member.

[0091] <Evaluation of connection structures> After the high-temperature, high-humidity test of the connection structure, the connection resistance was measured at 14 locations using a four-terminal measurement method, and the maximum connection resistance value (maximum resistance value) was evaluated. The high-temperature, high-humidity test was performed by storing the connection structure in a high-temperature, high-humidity chamber at a temperature of 85°C and a humidity of 85% RH for 250 hours. A multimeter (MLR21, manufactured by ETAC) was used to measure the connection resistance. After the high-temperature, high-humidity test of the connection structure, the interface between the first circuit member and the circuit connection adhesive film was observed from the side opposite the adhesive surface of the first circuit member to the circuit connection adhesive film using an FPD / LSI inspection microscope (Nikon Instech Corporation, ECLIPSE L300ND) to evaluate adhesion. A score of "good" indicates that no peeling occurred at the interface between the first circuit member and the circuit connection adhesive film, and a score of "poor" indicates that peeling occurred. The evaluation results are shown in Tables 1 and 2.

[0092] [Table 1]

[0093] [Table 2] [Explanation of symbols]

[0094] 1...adhesive film for circuit connection, 1A...first adhesive layer, 1B...second adhesive layer, 2, 2A, 2B...adhesive component, 3, 3A...conductive particles, 4...first circuit member, 5...second circuit member, 6...connection portion, 7...insulating material, 10...structure, 41...first circuit board, 42...first electrode, 51...second circuit board, 52...second electrode.

Claims

1. An adhesive film for circuit connection, comprising an amide having a lactam ring, a cationic polymerizable compound, a thermal polymerization initiator, and conductive particles.

2. 2. The adhesive film for circuit connection according to claim 1, wherein the lactam ring of the amide has 3 to 12 carbon atoms.

3. 3. The adhesive film for circuit connection according to claim 1, wherein the amide comprises ε-caprolactam.

4. 4. The adhesive film for circuit connection according to claim 1, wherein the cationically polymerizable compound comprises at least one selected from the group consisting of oxetane compounds and alicyclic epoxy compounds.

5. The content of the amide by mass is A Ｗ The content of the thermal polymerization initiator by mass is B Ｗ When this is done, A Ｗ / B Ｗ The adhesive film for circuit connection according to any one of claims 1 to 4, wherein is 0.001 to 0.

2.

6. a first adhesive layer and a second adhesive layer laminated on the first adhesive layer; 6. The adhesive film for circuit connection according to claim 1, wherein the first adhesive layer contains the amide, the cationically polymerizable compound, the thermal polymerization initiator, and the conductive particles.

7. a first circuit member having a first electrode; a second circuit member having a second electrode; a connection portion disposed between the first circuit member and the second circuit member, electrically connecting the first electrode and the second electrode to each other; Equipped with A connection structure, wherein the connection portion comprises a cured product of the adhesive film for circuit connection according to any one of claims 1 to 6.

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

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