Manufacturing method of wound body of glue film for circuit connection and wound body of glue film for circuit connection

Abstract

To provide a wound body of a glue film for circuit connection having desired conductive particle capturing properties and a manufacturing method thereof.SOLUTION: There is provided a manufacturing method of a wound body of a glue film for circuit connection including a substrate, a first adhesive layer disposed on the substrate and containing a thermo-curable composition and a second adhesive layer containing a conductive particle and the thermo-curable composition. The method includes: a step S1 of preparing a rolled web obtained by rolling up a laminate including a first substrate, the first adhesive layer containing the thermo-curable composition, the second adhesive layer containing the conductive particle and the thermo-curable composition, and a second substrate in this order; and a step S2 of obtaining a wound body of a glue film for circuit connection through winding up to a core after a treatment including cutting the laminate rolled out from the rolled web in a prescribed width and removing one of the first substrate and the second substrate. In the step S2, just one time is allocated for winding up the laminate with one of the first substrate and the second substrate removed.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a wound body of an adhesive film for circuit connection and a wound body of an adhesive film for circuit connection.

Background Art

[0002] Conventionally, various adhesive materials have been used for circuit connection. For example, as an adhesive material for connecting a liquid crystal display and a tape carrier package (TCP), connecting a flexible printed wiring board (FPC) and a TCP, or connecting an FPC and a printed wiring board, an anisotropic conductive adhesive film in which conductive particles are dispersed in an adhesive is used.

[0003] In recent years, in the field of precision electronic devices, the density of circuits has been increasing, and the electrode width and the electrode interval have become extremely narrow. When connecting such a circuit with an adhesive film for circuit connection, it is required to reduce the connection resistance by capturing more conductive particles between opposing circuit electrodes while ensuring the insulation between adjacent circuit electrodes.

[0004] Regarding techniques for improving the conductive particle capturing property of an adhesive film containing conductive particles, studies have been made so far. For example, an adhesive film for circuit connection having two layers, a conductive adhesive layer containing conductive particles and an insulating adhesive layer, has been proposed (see, for example, Patent Document 1 below).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] By the way, the circuit connection adhesive film is usually used in a form obtained by cutting a laminate having an adhesive layer provided on a base material such as a polyethylene terephthalate (PET) film into a strip (or tape) shape so as to have a width suitable for the intended use. Such a circuit connection adhesive film is supplied as a wound body (for example, a reel body) wound around a winding core.

[0007] Although the circuit connection adhesive film having the above-described multilayer adhesive layer is also supplied and used as a wound body, it has been clarified by the study of the present inventors that a difference occurs in the conductive particle capturing property of the circuit connection adhesive film due to the difference in the process of manufacturing the wound body.

[0008] Therefore, the main object of the present invention is to provide a wound body of a circuit connection adhesive film having a desired conductive particle capturing property and a method for manufacturing the same.

Means for Solving the Problems

[0009] The present invention provides the inventions described in the following [1] to [8]. [1] A method for manufacturing a wound body of a circuit connection adhesive film having a base material, a first adhesive layer containing a thermosetting composition, and a second adhesive layer containing conductive particles and a thermosetting composition provided on the base material, the method comprising: a step S1 of preparing a roll-shaped raw web obtained by winding a laminate having, in this order, a first base material, a first adhesive layer containing a thermosetting composition, a second adhesive layer containing conductive particles and a thermosetting composition, and a second base material; and a step S2 of obtaining the wound body of the circuit connection adhesive film by winding the laminate unwound from the roll-shaped raw web through a process including cutting the laminate to a predetermined width and peeling one of the first base material and the second base material, and then winding it around a winding core, wherein in the step S2, winding of the laminate from which one of the first base material and the second base material has been peeled is provided only once. A method for manufacturing a wound body of a circuit connection adhesive film. [2] The method for manufacturing a wound body of a circuit connection adhesive film according to [1], wherein the second base material is peeled in the step S2. [3] The method for manufacturing a wound body of an adhesive film for circuit connection according to [1] or [2], wherein the step S2 includes cutting the laminate from which one of the first base material and the second base material has been peeled off to a width of 0.5 to 3 mm. [4] A wound body in which an adhesive film for circuit connection having a base material and an adhesive layer provided on the base material is wound around a winding core, wherein the adhesive layer includes a first adhesive layer containing a thermosetting composition and a second adhesive layer containing conductive particles and a thermosetting composition, and when the adhesive film for circuit connection is unwound from the wound body, the root mean square height of the surface of the adhesive layer on the side opposite to the base material side is 0.005 to 0.1 μm. [5] The wound body according to [4], wherein when the adhesive film for circuit connection is unwound from the wound body, the kurtosis of the surface of the adhesive layer on the side opposite to the base material side is 2.8 to 4. [6] The wound body according to [4] or [5], wherein the second adhesive layer further contains a cured product of a photocurable resin component. [7] The wound body according to any one of [4] to [6], wherein the adhesive film for circuit connection has the base material, the first adhesive layer, and the second adhesive layer in this order. [8] A raw material web for forming an adhesive film for circuit connection, comprising a wound body in which a laminate having a first base material, a first adhesive layer containing a thermosetting composition, a second adhesive layer containing conductive particles and a thermosetting composition, and a second base material in this order is wound around a winding core.

[0010] According to the manufacturing method described in [1], a wound body of an adhesive film for circuit connection having desired conductive particle capturing properties can be manufactured. The reason for such an effect is that in the process from preparing the roll-shaped web to obtaining the wound body of the adhesive film for circuit connection, by performing the winding of the laminate in which one of the first base material and the second base material is peeled off only at the end of step S2, when the adhesive film for circuit connection is unwound from the wound body, it is possible to suppress the surface state on the side opposite to the base material side of the adhesive layer, which is the sticking surface to the circuit member, from becoming too rough. Thus, it is considered that it was possible to prevent the decrease in the capturing property of the conductive particles. In step S2, for example, when performing one or two or more processes such as cutting the laminate to a predetermined width, inspection such as foreign matter inspection, and treatment such as light irradiation, these processes may be performed on the laminate unwound with the adhesive layer disposed between the two base materials, or may be performed on the laminate in which one of the first base material and the second base material is peeled off.

[0011] According to the wound body of the adhesive film for circuit connection described in [4], since the surface on the side opposite to the base material side of the adhesive layer, which is the sticking surface to the circuit member, has the above specific root mean square height, it can have desired conductive particle capturing properties.

Advantages of the Invention

[0012] According to the present invention, it is possible to provide a wound body of an adhesive film for circuit connection having desired conductive particle capturing properties and a method for manufacturing the same.

Brief Description of the Drawings

[0013]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following description, the same or corresponding parts are denoted by the same reference numerals, and redundant descriptions are omitted. Note that the present invention is not limited to the following embodiments.

[0015] In this specification, a numerical range indicated by "~" indicates a range that includes the numerical values described before and after "~" as the minimum value and the maximum value, respectively. In the numerical ranges described step by step in this specification, the upper limit value or the lower limit value of a numerical range at a certain step may be replaced with the upper limit value or the lower limit value of a numerical range at another step. Also, in the numerical ranges described in this specification, the upper limit value or the lower limit value of the numerical range may be replaced with the value shown in the examples. Further, the individually described upper limit value and lower limit value can be arbitrarily combined. In the notation of the numerical range "A~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 "numerical values exceeding 10", and the same applies when the numerical values are different. Also, for example, the description "10 or less" means "10" and "numerical values less than 10", and the same applies when the numerical values are different. Also, in this specification, "(meth)acrylate" means at least one of acrylate and the corresponding methacrylate. The same applies to other similar expressions such as "(meth)acryloyl" and "(meth)acrylic acid". Also, "A or B" means that either A or B may be included, or both may be included. Also, the materials exemplified below may be used alone or in combination of two or more, unless otherwise specified. The content of each component in the composition means the total amount of the plurality of substances corresponding to each component present in the composition, unless otherwise specified, when there are a plurality of substances corresponding to each component in the composition.

[0016] <Wound body of adhesive film for circuit connection> The wound body of the adhesive film for circuit connection of the present embodiment is a wound body in which an adhesive film for circuit connection having a base material and an adhesive layer provided on the base material is wound around a winding core, and the adhesive layer includes a first adhesive layer containing a thermosetting composition and a second adhesive layer containing conductive particles and a thermosetting composition. The above adhesive film for circuit connection may be wound around the winding core so that the above base material is on the outside, or may be wound around the winding core so that the above base material is on the inside.

[0017] The wound body of the adhesive film for circuit connection of the present embodiment can be used, for example, in the following method for manufacturing a circuit connection structure. The method for manufacturing a circuit connection structure includes interposing an adhesive layer in the adhesive film for circuit connection unwound from the wound body between a first circuit member having a first electrode (circuit electrode) and a second circuit member having a second electrode (circuit 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. In this case, the adhesive layer of the adhesive film for circuit connection functions as an anisotropic conductive adhesive layer.

[0018] The above method may include a laminating step of laminating the adhesive film for circuit connection unwound from the wound body on the first circuit member in a state having a base material so that the adhesive layer contacts the first circuit member, a peeling step of peeling the base material from the adhesive film for circuit connection attached to the first circuit member, and a heating and pressing step of arranging the second circuit member on the first circuit member laminated with the adhesive layer so that the first electrode and the second electrode face each other, and pressing the first circuit member and the second circuit member in the direction in which the first electrode and the second electrode face each other while heating the adhesive layer. Further, the laminating step and the peeling step may be changed to a step of laminating the adhesive layer in close contact with the first circuit member after or while peeling the base material.

[0019] The laminating method is not particularly limited, and a roll laminator, a diaphragm laminator, a vacuum roll laminator, or a vacuum diaphragm laminator can be adopted. After provisional lamination, pressure bonding may be performed using a thermocompression bonding device.

[0020] As the heating means, a known thermocompression bonding device can be used. As the pressing means, a known thermocompression bonding device can be used.

[0021] FIG. 1 is a cross-sectional view showing an example of a wound body of an adhesive film for circuit connection according to the present embodiment. The wound body 100 shown in FIG. 1 has a configuration in which an adhesive film 60 for circuit connection having a base material 101 and an adhesive layer 102 provided on the base material 101 is wound around the outer surface F1 of a winding core 110. The adhesive film 60 for circuit connection is wound such that the adhesive layer 102 faces the winding core 110 side and the base material 101 faces the outside. In the wound body 100, the inner surface S2 of the adhesive layer 102 is in contact with the outer surface F1 of the winding core 110 or the outer surface S1 of the base material 101.

[0022] As the base material 101, for example, a base material (for example, a film) made of polyolefin such as stretched polypropylene (OPP), polyethylene terephthalate (PET), polyethylene naphthalate, polyethylene isophthalate, polybutylene terephthalate, polyethylene, polypropylene, 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. An arbitrary filler may be contained in the base material. Examples of the filler include oxides such as titanium oxide. Further, the surface of the base material may be subjected to a release treatment or a plasma treatment or the like.

[0023] The wound body 100 of the adhesive film for circuit connection may be used as a reel body. The configuration of the reel body is not particularly limited, and a known configuration can be adopted. For example, it may include a winding core 110, a pair of side plates provided at both ends of the winding core so as to face each other, and the wound body 100 of the adhesive film for circuit connection according to the present embodiment wound around the winding core. In FIG. 1, the adhesive film 60 for circuit connection (that is, the adhesive films 56 and 58 for circuit connection) is wound around the winding core 110 such that the base material 101 faces the outside, but even when the adhesive film 60 for circuit connection is wound around the winding core 110 such that the base material 101 faces the inside, the wound body of the adhesive film for circuit connection may be used as a reel body in the same manner.

[0024] The thickness of the adhesive film for circuit connection (in FIG. 1, the total thickness of the base material 101 and the adhesive layer 102) may be, for example, 5.0 μm or more, 8.0 μm or more, 10.0 μm or more, 25.0 μm or more, 35.0 μm or more, or 45.0 μm or more, and may be 100.0 μm or less, 80.0 μm or less, 70.0 μm or less, 60.0 μm or less, or 40.0 μm or less.

[0025] The thickness of the adhesive layer in the adhesive film for circuit connection (in FIG. 1, the thickness of the adhesive layer 102) may be, for example, 2.0 μm or more, 5.0 μm or more, 6.0 μm or more, or 7.0 μm or more, and may be 40.0 μm or less, 20.0 μm or less, 10.0 μm or less, or 3.0 μm or less.

[0026] From the viewpoint of facilitating the capture of conductive particles between electrodes, when the adhesive film for circuit connection is unwound from the wound body, the root mean square height (Sq) of the surface on the side opposite to the base material side of the adhesive layer (S2 surface of the adhesive layer 102 in FIG. 1) may be 0.005 to 0.1 μm. Further, from the viewpoint of facilitating the unwinding of the adhesive film for circuit connection from the wound body, Sq may be 0.005 μm or more, or 0.001 μm or more, and from the viewpoint of facilitating the capture of conductive particles between electrodes, Sq may be 0.1 μm or less, or 0.05 μm or less. Also, by satisfying the above upper limit value of Sq, the ease of peeling the base material from the adhesive film for circuit connection after thermocompression bonding the adhesive film for circuit connection to a circuit member or the like without peeling the base material (hereinafter sometimes referred to as "reworkability of the base material") can be improved.

[0027] The circuit connection structure obtained using the circuit connection adhesive film has the characteristic that the connection resistance between the connected electrodes is less likely to increase even after a reliability test under high temperature and high humidity conditions (for example, a temperature of 85 °C and a humidity of 85%) (hereinafter, may be referred to as "connection reliability"). In some cases, it is required to have such a characteristic. From the viewpoints of connection reliability and conductive particle capturing property, when the circuit connection adhesive film is unwound from the wound body, the kurtosis (Sku) of the surface on the side opposite to the base material side of the adhesive layer (the S2 surface of the adhesive layer 102 in FIG. 1) may be 2.8 to 4, or may be 2.9 to 3.5.

[0028] From the viewpoints of connection reliability and conductive particle capturing property, when the circuit connection adhesive film is unwound from the wound body, the arithmetic mean height (Sa) of the surface on the side opposite to the base material side of the adhesive layer (the S2 surface of the adhesive layer 102 in FIG. 1) may be 0.005 to 0.1 μm, may be 0.005 to 0.05 μm, or may be 0.005 to 0.03 μm.

[0029] From the viewpoints of connection reliability and conductive particle capturing property, when the circuit connection adhesive film is unwound from the wound body, the skewness (Ssk) of the surface on the side opposite to the base material side of the adhesive layer (the S2 surface of the adhesive layer 102 in FIG. 1) may be -0.9 to 0, may be -0.8 to 0, or may be -0.7 to 0.

[0030] In FIG. 1, the circuit connection adhesive film 60 is wound around the winding core 110 with the base material 101 facing outward. However, even when the circuit connection adhesive film 60 is wound around the winding core 110 with the base material 101 facing inward, the Sq, Sku, Sa, and Ssk of the above surface of the circuit connection adhesive film may be the same as the above numerical ranges.

[0031] Sq, Sku, Sa, and Ssk can be obtained, for example, by the method described in the examples. Specifically, using a laser microscope OLS4100 (manufactured by Olympus), photograph the surface on the side opposite to the base material side of the adhesive layer of the circuit connection adhesive film unwound from the reel, and the parameters of the surface roughness can be calculated using the attached surface analysis software. The photographing can be performed at a magnification of 100 times with an objective lens. In the attached surface analysis software, regarding the cut-off wavelength during analysis, λs may be 25 μm, and λc and λf do not necessarily need to be set.

[0032] In the reel of the circuit connection adhesive film of this embodiment, from the viewpoint of easily obtaining connection reliability and conductive particle capturing property, when the circuit connection adhesive film is unwound from the reel, the root mean square height (Sq) of the surface on the side opposite to the adhesive layer side of the base material (S1 surface of the base material 101 in FIG. 1) may be 0.005 to 0.3 μm, 0.005 to 0.1 μm, or 0.005 to 0.01 μm. Also, by having Sq satisfy the above range, the reworkability of the base material is easily obtained.

[0033] In the reel of the circuit connection adhesive film of this embodiment, from the viewpoint of easily obtaining connection reliability and conductive particle capturing property, when the circuit connection adhesive film is unwound from the reel, the arithmetic mean height (Sa) of the surface on the side opposite to the adhesive layer side of the base material (S1 surface of the base material 101 in FIG. 1) may be 0.005 to 0.2 μm, 0.005 to 0.1 μm, or 0.005 to 0.01 μm. Also, by having Sa satisfy the above range, the reworkability of the base material is easily obtained.

[0034] In FIG. 1, the circuit connection adhesive film 60 is wound around the reel core 110 with the base material 101 facing outward. However, even when the circuit connection adhesive film 60 is wound around the reel core 110 with the base material 101 facing inward, Sq and Sa of the above surface of the base material may be the same as the above numerical ranges.

[0035] The circuit connection adhesive film according to this embodiment will be further described in detail below with reference to the drawings.

[0036] FIG. 2 is an enlarged cross-sectional view showing an example of an adhesive film for circuit connection. The circuit connection adhesive film 56 shown in FIG. 2 includes a base material 11, a first adhesive layer 12 containing a thermosetting composition provided on one surface of the base material 11, and an adhesive layer 102a including, in this order from the base material 11 side, a second adhesive layer 22 containing a plurality of conductive particles 1 and an adhesive component 2 containing a thermosetting composition. In the circuit connection adhesive film 56 shown in FIG. 2, a part of the conductive particles 1 is exposed from the surface of the second adhesive layer 22 (for example, protruding toward the first adhesive layer 12 side), but the entire conductive particles 1 may be embedded in the second adhesive layer 22 so that the conductive particles 1 are not exposed from the surface of the second adhesive layer 22. In the circuit connection adhesive film 56, the base material 11 is peeled off during use.

[0037] FIG. 3 is an enlarged cross-sectional view showing another example of an adhesive film for circuit connection. The circuit connection adhesive film 58 shown in FIG. 3 includes a base material 21, a second adhesive layer 22 containing a plurality of conductive particles 1 and an adhesive component 2 containing a thermosetting composition provided on one surface of the base material 21, and an adhesive layer 102b including, in this order from the base material 21 side, a first adhesive layer 12 containing a thermosetting composition. In FIG. 3, a part of the conductive particles 1 is exposed from the surface of the second adhesive layer 22 (for example, protruding toward the first adhesive layer 12 side), but the entire conductive particles 1 may be embedded in the second adhesive layer 22 so that the conductive particles 1 are not exposed from the surface of the second adhesive layer 22. In the circuit connection adhesive film 58, the base material 21 is peeled off during use.

[0038] In the manufacturing method of the circuit connection structure described above, the circuit connection adhesive film 56 can be laminated on the first circuit member so that the second adhesive layer 22 contacts the first circuit member, and the circuit connection adhesive film 58 can be laminated on the first circuit member so that the first adhesive layer 12 contacts the first circuit member.

[0039] As the base materials 11 and 21, the same materials as the above-described base materials can be used. The Sq and Sa of the surfaces of the base materials 11 and 21 on the side opposite to the adhesive layer side may be the same as the above numerical ranges.

[0040] In the circuit connection adhesive film 56, the surface of the second adhesive layer 22 on the side opposite to the base material 11 side may satisfy any of the above-described conditions of Sq, Sku, Sa, and Ssk. In the circuit connection adhesive film 58, the surface of the first adhesive layer 12 on the side opposite to the base material 21 side may satisfy any of the above-described conditions of Sq, Sku, Sa, and Ssk.

[0041] Next, each component constituting the first adhesive layer 12 and the second adhesive layer 22 will be described.

[0042] (First Adhesive Layer) The first adhesive layer may be an insulating adhesive layer composed of a non-conductive component (insulating resin component). The first adhesive layer contains a thermosetting composition. The thermosetting composition is a composition that is at least partially cured by heat and may contain a thermosetting resin component (hereinafter sometimes referred to as “component (A)”).

[0043] [Component (A): Thermosetting Resin Component] Component (A) is not particularly limited as long as it is a resin component that cures by heat. For example, it may contain a cationic polymerizable compound (hereinafter sometimes referred to as “component (A1)”) and a thermal cationic polymerization initiator (hereinafter sometimes referred to as “component (A2)”). Component (A) may be a component composed of component (A1) and component (A2).

[0044] (A1) Component: Cationic Polymerizable Compound (A1) component is a compound that crosslinks by reacting with (A2) component upon heating. Here, (A1) component means a compound having no radically polymerizable group that reacts with radicals, and (A1) component is not included in (F1) component. Examples of (A1) component include compounds having a cyclic ether group such as oxetane compounds and epoxy compounds. (A1) component may be used alone or in combination of multiple components. From the viewpoint of further improving the effect of reducing the connection resistance and being more excellent in connection reliability, (A1) component may include at least one selected from the group consisting of oxetane compounds and alicyclic epoxy compounds, for example. From the viewpoint of easily obtaining a desired melt viscosity, (A1) component may include both at least one oxetane compound and at least one alicyclic epoxy compound.

[0045] The oxetane compound as (A1) component can be used without particular limitation as long as it has an oxetanyl group and no radically polymerizable group. Commercially available oxetane compounds include, for example, ETERNACOLL OXBP (trade name, 4,4’-bis[(3-ethyl-3-oxetanyl)methoxymethyl]biphenyl, manufactured by Ube Industries, Ltd.), OXSQ, OXT-121, OXT-221, OXT-101, OXT-212 (trade name, manufactured by Toagosei Co., Ltd.), etc. These may be used alone or in combination of multiple compounds.

[0046] The alicyclic epoxy compound as (A1) component can be used without particular limitation as long as it has an alicyclic epoxy group (e.g., epoxycyclohexyl group) and no radically polymerizable group. Commercially available alicyclic epoxy compounds include, for example, EHPE3150, EHPE3150CE, Celoxide 8010, Celoxide 2021P, Celoxide 2081 (trade name, manufactured by Daicel Corporation), etc. These may be used alone or in combination of multiple compounds.

[0047] (A2) component: Thermal cationic polymerization initiator (Component (A2) is a thermal polymerization initiator that generates an acid or the like upon heating to initiate polymerization. Component (A2) may be a salt compound composed of a cation and an anion. Component (A2) is, for example, BF 4 - , BR 4 - (R represents a phenyl group substituted with two or more fluorine atoms or two or more trifluoromethyl groups), PF 6 - , SbF 6 - , AsF 6 - and the like, and examples include onium salts such as sulfonium salts, phosphonium salts, ammonium salts, diazonium salts, iodonium salts, anilinium salts, and pyridinium salts having anions. These may be used alone or in combination of two or more.

[0048] From the viewpoint of storage stability, component (A2) is, for example, an anion containing boron as a constituent element, i.e., BF 4 - or BR 4 - (R represents a phenyl group substituted with two or more fluorine atoms or two or more trifluoromethyl groups), and may be a salt compound. The anion containing boron as a constituent element may be BR 4 -, and more specifically, may be tetrakis(pentafluorophenyl)borate.

[0049] Since the onium salt as component (A2) has resistance to substances that can cause curing inhibition to cationic curing, it may be, for example, an anilinium salt. Examples of the anilinium salt compound include N,N-dialkylanilinium salts such as N,N-dimethylanilinium salt and N,N-diethylanilinium salt.

[0050] (A2) component may be anilinium salt having an anion containing boron as a constituent element. Examples of commercially available products of such salt compounds include CXC-1821 (trade name, manufactured by King Industries), etc.

[0051] From the viewpoint of ensuring the formability and curability of the first adhesive layer, the content of (A2) component may be, for example, 0.001 to 1 part by mass, 0.005 to 0.7 part by mass, 0.01 to 0.5 part by mass, or 0.03 to 0.3 part by mass with respect to 100 parts by mass of (A1) component.

[0052] From the viewpoint of maintaining reliability, the content of (A) component may be 5% by mass or more, 10% by mass or more, 15% by mass or more, or 20% by mass or more based on the total mass of the first adhesive layer. From the viewpoint of preventing resin bleeding defects in a reel which is one aspect of the supply form, the content of (A) component may be 80% by mass or less, 70% by mass or less, 60% by mass or less, or 50% by mass or less based on the total mass of the first adhesive layer. When the content of (A) component is within the above range, the effects of the present invention tend to be remarkably exhibited.

[0053] [Other components] The first adhesive layer may further contain other components. Examples of other components include, for example, a thermoplastic resin (hereinafter may be referred to as "(B) component"), a coupling agent (hereinafter may be referred to as "(C) component"), and a filler (hereinafter may be referred to as "(D) component"), etc.

[0054] Examples of component (B) 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 individually or in combination. Among these, component (B) may be, for example, phenoxy resin. The content of component (B) may be 1% by mass or more, 3% by mass or more, or 5% by mass or more, and may be 60% by mass or less, 40% by mass or less, or 20% by mass or less, based on the total mass of the first adhesive layer.

[0055] Examples of component (C) include silane coupling agents having organic functional groups such as (meth)acryloyl group, mercapto group, amino group, imidazole group, epoxy group, etc., silane compounds such as tetraalkoxysilane, tetraalkoxytitanate derivatives, polydialkyl titanate derivatives, etc. These may be used individually or in combination. By the first adhesive layer containing component (C), the adhesiveness can be further improved. Component (C) may be, for example, a silane coupling agent. The content of component (C) may be 0.1 to 10% by mass, based on the total mass of the first adhesive layer.

[0056] (D) components include, for example, non-conductive fillers (e.g., non-conductive particles). The (D) component may be either an inorganic filler or an organic filler. Examples of the inorganic filler include metal oxide fine particles such as silica fine particles, alumina fine particles, silica-alumina fine particles, titania fine particles, and zirconia fine particles; and inorganic fine particles such as metal nitride fine particles. Examples of the organic filler include organic fine particles such as silicone fine particles, methacrylate-butadiene-styrene fine particles, acrylic-silicone fine particles, polyamide fine particles, and polyimide fine particles. These may be used individually or in combination. The (D) component may be, for example, silica fine particles. The content of the (D) component may be 1% by mass or more, 10% by mass or more, or 30% by mass or more, and may be 90% by mass or less, 70% by mass or less, or 50% by mass or less, based on the total mass of the first adhesive layer.

[0057] [Other Additives] The first adhesive layer may further contain other additives such as plasticizers, accelerators, anti-degradants, colorants, flame retardants, and thixotropic agents. The content of the other additives may be, for example, 0.1 to 10% by mass based on the total mass of the first adhesive layer.

[0058] The thickness of the first adhesive layer may be appropriately set according to the height of the electrodes of the circuit member to be adhered, etc. The thickness of the first adhesive layer may be 5.0 μm or more or 6.0 μm or more, and may be 30.0 μm or less, 20.0 μm or less, 15.0 μm or less, or 13.0 μm or less, from the viewpoint of sufficiently filling the space between the electrodes to seal the electrodes and obtaining better connection reliability. Note that, as shown in FIGS. 2 and 3, when a part of the conductive particles 1 contained in the second adhesive layer 22 is exposed from the surface of the second adhesive layer 22 (e.g., protruding toward the first adhesive layer 12 side), the distance from the surface of the first adhesive layer 12 on the side opposite to the second adhesive layer 22 side to the boundary between the second adhesive layer 22 and the first adhesive layer 12 located at the separation part between adjacent conductive particles 1 (the distance indicated by d2 in FIGS. 2 and 3) is the thickness of the first adhesive layer 12.

[0059] The thickness of the first adhesive layer can be determined, for example, by the method described in the examples. Specifically, two sheets of circuit connection adhesive film are sandwiched between two pieces of glass (thickness: about 1 mm), and after casting with 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 Tech Co., Ltd.), cross-section polishing is performed using a polishing machine, and it can be measured by using a scanning electron microscope (SEM, trade name: SE-8020, manufactured by Hitachi High-Technologies Corporation). Such an operation may be performed multiple times, and the average value may be taken as the thickness of the first adhesive layer.

[0060] (Second adhesive layer) The second adhesive layer contains conductive particles (hereinafter sometimes referred to as the "(E) component") and a thermosetting composition. The second adhesive layer may be a component having no conductivity (for example, an insulating resin component) other than the (E) component. The thermosetting composition is a composition that is at least partially cured by heat and may contain the above-described (A) component. The second adhesive layer may further contain a photocurable resin component (hereinafter sometimes referred to as the "(F) component"). When the second adhesive layer contains the (F) component, the second adhesive layer may contain a cured product of the (F) component. The cured product of the (F) component may be a cured product obtained by completely curing the (F) component, or a cured product obtained by partially curing the (F) component. The second adhesive layer can be obtained, for example, by irradiating a composition layer composed of a composition containing the (E) component, the thermosetting composition, and the (F) component with light energy to polymerize the components contained in the (F) component to form a cured product of the (F) component. The thermosetting composition is a component that is flowable during circuit connection.

[0061] [(E) component: Conductive particles] (Component (E) is not particularly limited as long as it is conductive particles, and may be metal particles composed of metals such as Au, Ag, Pd, Ni, Cu, solder, etc., or conductive carbon particles composed of conductive carbon. (Component (E) may be coated conductive particles including a core containing non-conductive glass, ceramic, plastic (such as polystyrene), etc. and a coating layer containing the above metal or the above conductive carbon and covering the core. (Component (E) may be used alone or in combination of a plurality of various conductive particles. (Component (E) may be coated conductive particles including a core containing plastic and a coating layer containing metal or conductive carbon and covering the core, or metal particles formed of a heat-melting metal.

[0062] (When component (E) is coated conductive particles, since the cured product of the thermosetting resin component can be easily deformed by heating or pressurization, when electrically connecting the electrodes, the contact area between the electrode and component (E) can be increased, and the conductivity between the electrodes can be further improved.

[0063] (When component (E) is metal particles formed of a heat-melting metal, the connection between the electrodes tends to be stronger. This tendency is remarkable when using solder particles as component (E).

[0064] The solder particles may contain at least one selected from the group consisting of tin, tin alloy, indium, and indium alloy from the viewpoint of achieving both connection strength and low melting point. Further, the solder particles may contain at least one selected from the group consisting of In - Bi alloy, In - Sn alloy, In - Sn - Ag alloy, Sn - Au alloy, Sn - Bi alloy, Sn - Bi - Ag alloy, Sn - Ag - Cu alloy, and Sn - Cu alloy from the viewpoint of obtaining higher reliability during the high temperature and high humidity test and the thermal shock test.

[0065] (E) component may be insulating-coated conductive particles including the above metal particles, the above conductive carbon particles, or the above coated conductive particles, and an insulating material such as resin, and having an insulating layer covering the surface of the particles. When the (E) component is insulating-coated conductive particles, even when the content of the (E) component is large, since the particles are provided with an insulating layer on their surfaces, generation of short circuits due to contact between the (E) components can be suppressed, and the insulation between adjacent electrode circuits can also be improved.

[0066] The maximum particle size of the (E) component needs to be smaller than the minimum electrode interval (the shortest distance between adjacent electrodes). From the viewpoint of excellent dispersibility and conductivity, the maximum particle size of the (E) component may be 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 maximum particle size of the (E) component may be 30.0 μm or less, 25.0 μm or less, 20.0 μm or less, 15.0 μm or less, 10.0 μm or less, or 5.0 μm or less. In this specification, for any 300 pieces (pcs) of the (E) component in the second adhesive layer, the particle size is measured by observation using a scanning electron microscope (SEM), and the largest value obtained is taken as the maximum particle size of the (E) component. When the (E) component has protrusions or the like and the (E) component is not spherical, the particle size of the (E) component is the diameter of a circle circumscribing the conductive particles in the SEM image.

[0067] From the viewpoint of excellent dispersibility and conductivity, the average particle size of the (E) component may be 1.0 μm or more, 2.0 μm or more, 2.5 μm or more, or 3.0 μm or more. From the viewpoint of excellent dispersibility and conductivity, the average particle size of the (E) component may be 20.0 μm or less, 10.0 μm or less, 7.0 μm or less, or 5.0 μm or less. In this specification, for any 300 pieces (pcs) of the (E) component in the second adhesive layer, 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.

[0068] In the second adhesive layer, the (E) component may be uniformly dispersed. The particle density of the (E) component in the circuit connection adhesive film is 100 pieces / mm from the viewpoint of obtaining a stable connection resistance. 21000 particles / mm or more 2 3000 particles / mm or more 2 5000 particles / mm or more 2 7000 particles / mm or more 2 10000 particles / mm or more 2 12000 particles / mm or more 2 The particle density of the (E) component in the circuit connection adhesive film may be 100000 particles / mm or less, 70000 particles / mm or less, 50000 particles / mm or less, 30000 particles / mm or less, or 20000 particles / mm or less from the viewpoint of improving the insulation between adjacent electrodes. 2 70000 particles / mm or less 2 50000 particles / mm or less 2 30000 particles / mm or less 2 20000 particles / mm or less 2 The content of the (E) component may be 1% by mass or more, 5% by mass or more, or 10% by mass or more based on the total mass of the second adhesive layer from the viewpoint of further improving conductivity. The content of the (E) component may be 60% by mass or less, 50% by mass or less, or 40% by mass or less based on the total mass of the second adhesive layer from the viewpoint of easily suppressing short circuits. When the content of the (E) component is within the above range, the effects of the present invention tend to be significantly exhibited. When the second adhesive layer contains the (F) component, the content of the (E) component in the composition or composition layer containing the (E) component, the thermosetting composition, and the (F) component (based on the total mass of the composition or composition layer) may be the same as the above range.

[0069] (E) component content, from the perspective of further improving conductivity, may be 1% by mass or more, 5% by mass or more, or 10% by mass or more based on the total mass of the second adhesive layer. (E) component content, from the perspective of easily suppressing short circuits, may be 60% by mass or less, 50% by mass or less, or 40% by mass or less based on the total mass of the second adhesive layer. When the content of the (E) component is within the above range, the effects of the present invention tend to be significantly demonstrated. When the second adhesive layer contains the (F) component, the content of the (E) component in the composition or composition layer containing the (E) component, the thermosetting composition, and the (F) component (based on the total mass of the composition or composition layer) may be the same as the above range.

[0070] [(A) component: Thermosetting resin component] The (A1) component and (A2) component used for the (A) component in the second adhesive layer are the same as those used for the (A) component in the first adhesive layer. The (A) component in the second adhesive layer may be the same as or different from the (A) component in the first adhesive layer.

[0071] The content of the (A) component may be 5% by mass or more, 10% by mass or more, 15% by mass or more, or 20% by mass or more based on the total mass of the second adhesive layer, from the viewpoint of ensuring the curability of the second adhesive layer. The content of the (A) component may be 70% by mass or less, 60% by mass or less, 50% by mass or less, or 40% by mass or less based on the total mass of the second adhesive layer, from the viewpoint of ensuring the formability of the second adhesive layer. When the content of the (A) component is within the above range, the effects of the present invention tend to be significantly exhibited. In addition, when the second adhesive layer contains the (F) component, the content of the (A) component in the composition or composition layer containing the (E) component, the thermosetting composition, and the (F) component (based on the total mass of the composition or composition layer) may be the same as the above range.

[0072] [(F) component: photocurable resin component] The (F) component is not particularly limited as long as it is a resin component that is cured by light irradiation, but when the (A) component is a resin component having cationic curability, the (F) component may be a resin component having radical curability from the viewpoint of better connection resistance. The (F) component may contain, for example, a radical polymerizable compound (hereinafter sometimes referred to as "(F1) component") and a photoradical polymerization initiator (hereinafter sometimes referred to as "(F2) component"). The (F) component may be a component consisting of the (F1) component and the (F2) component.

[0073] Component (F1): radical polymerizable compound The component (F1) is a compound that is polymerized by radicals generated from the component (F2) upon irradiation with light (e.g., ultraviolet light). The component (F1) may be either a monomer or a polymer (or oligomer) obtained by polymerizing one or more types of monomers. The component (F1) may be used alone or in combination.

[0074] (F1) component is a compound having a radically polymerizable group that reacts with radicals. Examples of the radically polymerizable group include, for example, (meth)acryloyl group, vinyl group, allyl group, styryl group, alkenyl group, alkenylene group, maleimide group, etc. The number of radically polymerizable groups (functional group numbers) possessed by the (F1) component may be 2 or more from the viewpoint that it is easy to obtain a desired melt viscosity after polymerization and it is excellent in connection reliability, and the effect of reducing connection resistance is further improved. From the viewpoint of suppressing the curing shrinkage during polymerization, it may be 10 or less, 6 or less, or 4 or less. Further, in order to balance the crosslinking density and the curing shrinkage, in addition to the compound in which the number of radically polymerizable groups is within the above range, a compound in which the number of radically polymerizable groups is outside the above range may be used.

[0075] (F1) component may contain a polyfunctional (bifunctional or more) (meth)acrylate from the viewpoint of suppressing the flow of conductive particles. The polyfunctional (bifunctional or more) (meth)acrylate may be a bifunctional or trifunctional (meth)acrylate, or may be a bifunctional (meth)acrylate. The bifunctional (meth)acrylate may be a bifunctional aromatic (meth)acrylate.

[0076] Examples of the polyfunctional (meth)acrylate include 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, glycerin di(meth)acrylate, tricyclodecane dimethanol (meth)acrylate, and 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; aliphatic (meth)acrylates such as 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; aromatic epoxy (meth)acrylates such as bisphenol type epoxy (meth)acrylate, phenol novolak type epoxy (meth)acrylate, cresol novolak type epoxy (meth)acrylate and the like can be mentioned.;

[0077] From the perspective of achieving both the effect of reducing connection resistance and suppressing particle flow, the content of polyfunctional (two or more functional groups) (meth)acrylate may be, for example, 50 to 100% by mass, 70 to 100% by mass, or 90 to 100% by mass based on the total mass of the (F1) component, and may be 100% by mass.

[0078] (Component (F1) may further contain a monofunctional (meth)acrylate in addition to a polyfunctional (meth)acrylate having two or more functional groups. Examples of the monofunctional (meth)acrylate include (meth)acrylic acid; aliphatic (meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, butoxyethyl (meth)acrylate, isoamyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, heptyl (meth)acrylate, octylheptyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-chloro-2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, ethoxypolyethylene glycol (meth)acrylate, methoxypolypropylene glycol (meth)acrylate, ethoxypolypropylene glycol (meth)acrylate, mono(2-(meth)acryloyloxyethyl) succinate; aromatic (meth)acrylates such as benzyl (meth)acrylate, phenyl (meth)acrylate, o-biphenyl (meth)acrylate, 1-naphthyl (meth)acrylate, 2-naphthyl (meth)acrylate, phenoxyethyl (meth)acrylate, p-cumylphenoxyethyl (meth)acrylate, o-phenylphenoxyethyl (meth)acrylate, 1-naphthoxyethyl (meth)acrylate, 2-naphthoxyethyl (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-naphthoxy)propyl (meth)acrylate, 2-hydroxy-3-(2-naphthoxy)propyl (meth)acrylate;Examples include (meth)acrylates having an epoxy group such as glycidyl (meth)acrylate, (meth)acrylates having an alicyclic epoxy group such as 3,4-epoxycyclohexylmethyl (meth)acrylate, and (meth)acrylates having an oxetanyl group such as (3-ethyloxetan-3-yl)methyl (meth)acrylate.;

[0079] The content of the monofunctional (meth)acrylate may be, for example, 0 to 50% by mass, 0 to 30% by mass, or 0 to 10% by mass based on the total mass of the component (F1), and may be 0% by mass.

[0080] The cured product of the component (F) may have a polymerizable group that reacts by means other than radicals, for example. The polymerizable group that reacts by means other than radicals may be, for example, a cationic polymerizable group that reacts by a cation. Examples of the cationic polymerizable group include an epoxy group such as a glycidyl group, an alicyclic epoxy group such as an epoxycyclohexylmethyl group, and an oxetanyl group such as an ethyloxetanylmethyl group. The cured product of the component (F) having a polymerizable group that reacts by means other than radicals can be introduced, for example, by using a (meth)acrylate having a polymerizable group that reacts by means other than radicals such as a (meth)acrylate having an epoxy group, a (meth)acrylate having an alicyclic epoxy group, or a (meth)acrylate having an oxetanyl group as the component (F). The mass ratio of the (meth)acrylate having a polymerizable group that reacts by means other than radicals to the total mass of the component (F1) (mass of the (meth)acrylate having a polymerizable group that reacts by means other than radicals (charged amount) / total mass of the component (F1) (charged amount)) may be, for example, 0 to 0.7, 0 to 0.5, or 0 to 0.3 from the viewpoint of improving reliability.

[0081] (F1) component may contain other radical polymerizable compounds in addition to polyfunctional (bi- or higher functionality) and monofunctional (meth)acrylates. Examples of other radical polymerizable compounds include maleimide compounds, vinyl ether compounds, allyl compounds, styrene derivatives, acrylamide derivatives, nadimide derivatives, and the like. The content of other radical polymerizable compounds may be, for example, 0 to 40% by mass based on the total mass of the (F1) component.

[0082] (F2) component: Photo radical polymerization initiator (F2) component is a photopolymerization initiator that generates radicals upon irradiation with light having wavelengths in the range of 150 to 750 nm, light having wavelengths in the range of 254 to 405 nm, or light having a wavelength of 365 nm (e.g., ultraviolet light). The (F2) component may be used alone or in combination of multiple components.

[0083] (F2) component decomposes upon exposure to light to generate free radicals. That is, the (F2) component is a compound that generates radicals upon the application of external light energy. The (F2) component may be a compound having a structure such as an oxime ester structure, a bisimidazole structure, an acridine structure, an α-aminoalkylphenone structure, an aminobenzophenone structure, an N-phenylglycine structure, an acylphosphine oxide structure, a benzyldimethylketal structure, an α-hydroxyalkylphenone structure, and the like. The (F2) component may be used alone or in combination of multiple components. The (F2) component may be a compound having at least one structure selected from the group consisting of an oxime ester structure, an α-aminoalkylphenone structure, and an acylphosphine oxide structure from the viewpoints of easily obtaining a desired melt viscosity and excellent reduction effect on connection resistance.

[0084] 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-benzoyloxime, 1,3-diphenylpropanetrione-2-(o-ethoxycarbonyl)oxime, 1-phenyl-3-ethoxypropanetrione-2-(o-benzoyl)oxime, 1,2-octanedione, 1-[4-(phenylthio)phenyl]-, 2-(o-benzoyloxime), ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]-, 1-(o-acetoxyoxime), and the like.

[0085] Specific examples of the compound having an α-aminoalkylphenone structure include 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1-morpholino(phenyl)-butanone-1, and the like.

[0086] 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, and the like.

[0087] (F2) component content may be, for example, 0.1 to 10 parts by mass, 0.3 to 7 parts by mass, or 0.5 to 5 parts by mass with respect to 100 parts by mass of the (F1) component, from the viewpoint of suppressing the flow of conductive particles.

[0088] The content of the cured product of component (F) may be 1% by mass or more, 5% by mass or more, or 10% by mass or more based on the total mass of the second adhesive layer, from the viewpoint of suppressing the flow of conductive particles. The content of the cured product of component (F) 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 second adhesive layer, from the viewpoint of exhibiting low resistance in low-pressure mounting. When the content of the cured product of component (F) is within the above range, the effects of the present invention tend to be remarkably exhibited. Note that the content of component (F) in the composition or composition layer (based on the total mass of the composition or composition layer) may be the same as the above range.

[0089] [Other components] The second adhesive layer may further contain other components. Examples of the other components include component (B), component (C), etc. Note that the component (B), component (C), and their aspects in the second adhesive layer are the same as those of component (B), component (C), and their aspects in the first adhesive layer.

[0090] The content of component (B) may be 1% by mass or more, 5% by mass or more, or 10% by mass or more based on the total mass of the second adhesive layer, and may be 70% by mass or less, 50% by mass or less, or 30% by mass or less. When the second adhesive layer contains component (F), the content of component (B) in the composition or composition layer containing component (E), the thermosetting composition, and component (F) (based on the total mass of the composition or composition layer) may be the same as the above range.

[0091] The content of component (C) may be 0.1 to 10% by mass based on the total mass of the second adhesive layer. When the second adhesive layer contains component (F), the content of component (C) in the composition or composition layer containing component (E), the thermosetting composition, and component (F) (based on the total mass of the composition or composition layer) may be the same as the above range.

[0092] [Other additives] The second adhesive layer may further contain other additives in the first adhesive layer. The aspects of the other additives are the same as those of the first adhesive layer.

[0093] The thickness of the second adhesive layer may be, for example, 30.0 μm or less, may be 20.0 μm or less, 15.0 μm or less, 10.0 μm or less, 8.0 μm or less, 5.0 μm or less, 4.5 μm or less, 4.0 μm or less, 3.5 μm or less, or 3.0 μm or less. By the thickness of the second adhesive layer being 30.0 μm or less, the resin content between the opposing circuits can be reduced, and an increase in the connection resistance between the opposing circuits can be suppressed. Such a tendency is more remarkable when the thickness of the second adhesive layer is 5.0 μm or less. The thickness of the second adhesive layer may be, for example, 0.1 μm or more, or 0.7 μm or more. As shown in FIGS. 2 and 3, when a part of the conductive particles 1 is exposed from the surface of the second adhesive layer 22 (for example, protruding toward the first adhesive layer 12 side), from the surface of the second adhesive layer 22 on the side opposite to the first adhesive layer 12 side, the distance (the distance indicated by d1 in FIGS. 2 and 3) from the second adhesive layer 22 located in the separated portion between the adjacent conductive particles 1, 1 to the boundary between the second adhesive layer 22 and the first adhesive layer 12 is the thickness of the second adhesive layer 22, and the exposed portion of the conductive particles 1 is not included in the thickness of the second adhesive layer 22. The length of the exposed portion of the conductive particles 1 may be, for example, 0.1 μm or more and may be 5.0 μm or less.

[0094] The thickness of the second adhesive layer can be obtained, for example, in the same manner as the measurement method of the thickness of the first adhesive layer described above.

[0095] From the viewpoint that the ratio of the thickness of the second adhesive layer to the average particle diameter of the conductive particles (thickness of the second adhesive layer / average particle diameter of the conductive particles) makes it easier for the conductive particles to be captured between the electrodes facing each other and can further reduce the connection resistance, it may be 0.1 or more, 0.3 or more, or 0.5 or more. The above ratio may be, for example, 2.0 or less, 1.5 or less, 1.2 or less, or 1.0 or less.

[0096] According to the wound body of the adhesive film for circuit connection according to the present embodiment, the adhesion between the adhesive film for circuit connection unwound from the wound body and circuit electrodes or the like can be improved when thermocompression bonding them. Further, the heating temperature in the thermocompression bonding between the adhesive film for circuit connection unwound from the wound body and circuit electrodes or the like can be reduced.

[0097] <Manufacturing method of wound body of adhesive film for circuit connection> The method for manufacturing the wound body of the adhesive film for circuit connection according to the present embodiment is a method for manufacturing a wound body of an adhesive film for circuit connection having a base material, a first adhesive layer containing a thermosetting composition provided on the base material, and a second adhesive layer containing conductive particles and a thermosetting composition, and includes a step S1 of preparing a roll-shaped raw material obtained by winding a laminate having a first base material, a first adhesive layer containing a thermosetting composition, a second adhesive layer containing conductive particles and a thermosetting composition, and a second base material in this order; and a step S2 of winding the laminate unwound from the roll-shaped raw material around a winding core through a process including cutting the laminate to a predetermined width and peeling one of the first base material and the second base material to obtain the wound body of the adhesive film for circuit connection. Further, in step S2, winding the laminate from which one of the first base material and the second base material has been peeled is provided only once.

[0098] In the manufacturing method of the wound body of the adhesive film for circuit connection, the first base material, the second base material, the first adhesive layer, and the second adhesive layer may be the same as those in the wound body of the adhesive film for circuit connection of the present embodiment described above.

[0099] <Step S1> In step S1, a roll-shaped raw material in which a laminate (sometimes referred to as laminate A) having a first base material, a first adhesive layer, a second adhesive layer, and a second base material in this order is wound around a winding core is prepared. The roll-shaped raw material may be one in which the laminate A is wound around the winding core with the first base material on the outside, or one in which the second base material is wound around the winding core on the outside. The width of the roll-shaped raw material is not particularly limited, but may be 25 to 60 cm.

[0100] Step S1 may include a step of preparing a laminate having a first adhesive layer formed on a first base material (first preparation step), a step of preparing a laminate having a second adhesive layer formed on a second base material (second preparation step), and a step of preparing a laminate A by bonding the laminate having the first adhesive layer formed on the first base material and the laminate having the second adhesive layer formed on the second base material so that the first adhesive layer and the second adhesive layer face each other (lamination step), and a step of winding the laminate A around a winding core to prepare a roll-shaped raw fabric (winding step). In step S1, a roll-shaped raw fabric prepared in advance may be used. Fig. 4 is a perspective view showing an example of the lamination step and the winding step, and Fig. 5 is an enlarged schematic cross-sectional view for explaining the steps shown in Fig. 4.

[0101] [First Preparation Step] In the first preparation step, for example, a first adhesive layer is formed on a first base material. Specifically, for example, components (A), (B), (C), and (D), and other components added as necessary are added into a solvent (organic solvent), and are dissolved or dispersed by stirring, mixing, kneading, etc. to prepare a composition for the first adhesive layer. Then, the adjusted composition for the first adhesive layer is applied onto the above-mentioned first base material using a knife coater, roll coater, applicator, comma coater, die coater, etc., and then the solvent is volatilized by heating to form a first adhesive layer on the first base material. Thereby, a laminate having a first adhesive layer formed on the first base material can be prepared.

[0102] As the solvent used for preparing the composition for the first adhesive layer, a solvent having the property of being able to uniformly dissolve or disperse each component may be used. Examples of such solvents include toluene, acetone, methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate, propyl acetate, butyl acetate and the like. These solvents can be used alone or in combination of two or more. Stirring, mixing and kneading during the preparation of the varnish composition can be carried out using, for example, a stirrer, a kneader, a three-roll mill, a ball mill, a bead mill or a homodisper.

[0103] The heating conditions when volatilizing the solvent from the composition for the first adhesive layer applied to the first substrate may be conditions under which the solvent is sufficiently volatilized. The heating conditions may be, for example, 40 °C or higher and 120 °C or lower for 0.1 minute or longer and 10 minutes or shorter.

[0104] A part of the solvent may remain without being removed in the first adhesive layer. The content of the solvent in such a layer may be, for example, 10% by mass or less based on the total mass of the first adhesive layer.

[0105] [Second Preparation Step] In the second preparation step, for example, a second adhesive layer is formed on the second substrate. Specifically, for example, a second adhesive layer is formed on the second substrate in the same manner as in the first preparation step except for using the components (E), (F), (A), (B), and (C) and other components added as necessary, whereby a laminate having the second adhesive layer formed on the second substrate can be prepared.

[0106] A part of the solvent may remain without being removed in the second adhesive layer. The content of the solvent in the second adhesive layer may be, for example, 10% by mass or less based on the total mass of the second adhesive layer.

[0107] [Lamination Step] In the lamination process, for example, as shown in FIGS. 4 and 5, on the surface of the first adhesive layer 12 on the side opposite to the first base material 11 in the laminate 10 having the first base material 11 and the first adhesive layer 12 provided thereon, and the second base material 21 and the second adhesive layer 22 provided thereon. The laminate 10 and the laminate 20 can be laminated such that the surfaces of the second adhesive layer 22 on the side opposite to the second base material 21 in the laminate 20 face each other. The temperature during lamination may be, for example, 0 to 80°C. The pressure (crimping pressure) during lamination may be, for example, 0.5 to 1.5 MPa. The lamination time (crimping time) may be, for example, 0.5 to 1.5 seconds.

[0108] [Rewinding process] In the rewinding process, the laminate A may be wound around a core such that the first base material is on the outside, or the second base material may be wound around the core such that it is on the outside, by a known method. In the rewinding process, the rewinding tension of the laminate A may be, for example, 10 to 50 N / m. In FIGS. 4 and 5, the laminate A52 is wound around the core such that the first base material 11 is on the outside, and a roll-shaped web 40 is obtained.

[0109] <Process S2> In process S2, the laminate unwound from the above roll-shaped web is cut to a predetermined width, and one of the first base material and the second base material is peeled off, and after undergoing the included treatment, it is wound around a core to obtain a wound body of the adhesive film for circuit connection. The process of cutting to a predetermined width may include a process of subdividing the roll-shaped web to obtain a wound body A with a smaller width (blocking process) and a slitting process of cutting to the width of the adhesive film for circuit connection.

[0110] Other processes include an inspection process for performing inspections such as foreign object inspection and appearance inspection, and a light irradiation process for performing light irradiation. These processes can be performed before peeling off one of the first base material and the second base material.

[0111] [Blocking process] In the blocking process, for example, as shown in FIG. 6, by a roll-to-roll method, the laminate A52 is unwound from the roll-shaped web 40, and the laminate A52 is cut into a predetermined width by a slit blade 92 to obtain a laminate A54, and the laminate A54 can be wound around a winding core to form a wound body A42. The unwinding tension of the laminate A and the winding tension of the laminate A may be, for example, 5 to 30 N / m. The blocking process may be performed multiple times. The cutting may be performed by a known method other than the slit blade.

[0112] In the blocking process, for example, with the laminate A52 having the first base material 11 and the second base material 21, the laminate A52 may be cut into a width of 10 to 30 mm, or 10 to 25 mm, and wound around a winding core to form a wound body A42.

[0113] [Inspection process] As the inspection process, for example, it may include unwinding the laminate from the roll-shaped web or the wound body A, performing foreign matter inspection on the laminate, and then winding the laminate around a winding core. Examples of the method for the foreign matter inspection include a method of visually observing foreign matters and a method of inspecting foreign matters with an appearance inspection machine.

[0114] [Light irradiation process] When the second adhesive layer contains the component (F), in step S1, a laminate having the second adhesive layer irradiated with light on the second base material before step S1 may be prepared, the second adhesive layer may be irradiated with light in step S1, and step S2 may include a light irradiation process. In the light irradiation process, by irradiating the second adhesive layer with light, a cured product of the component (F) is obtained from the component (F) contained in the second adhesive layer.

[0115] For the light irradiation, irradiation light (for example, ultraviolet light) including wavelengths in the range of 150 to 750 nm may be used. The light irradiation can be performed, for example, using 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. The integrated light amount of the irradiated light can be set as appropriate, but for example, it may be 500 to 3000 mJ / cm 2 and may be.

[0116] The light irradiation may be performed on the laminate in which the second adhesive layer is formed on the second base material in step S1, may be performed on the laminate unwound from the roll-shaped web in step S2, or may be performed on the adhesive film for circuit connection according to the present embodiment in step S2. The light irradiation may be directly applied to the second adhesive layer, may be performed through the second base material from the second base material side when the second base material transmits light, may be performed through the first adhesive layer from the first adhesive layer side when the first adhesive layer transmits light, or may be performed through the first base material and the first adhesive layer from the first base material side when the first base material and the first adhesive layer transmit light.

[0117] In step S2, a step of peeling one of the first base material and the second base material (peeling step) may be performed simultaneously with or before the slitting process. FIG. 7 is a perspective view showing an example of step S2. FIG. 8 is an enlarged schematic cross-sectional view for explaining the process shown in FIG. 7. In step S2 shown in FIGS. 7 and 8, the second base material 21 is peeled from the laminate 54 unwound from the wound body A42 obtained in the blocking step, and the adhesive film 55 for circuit connection from which the second base material 21 has been peeled is slit to a predetermined width by the rotary blade 94 to obtain a wound body 100 of the adhesive film 56 for circuit connection. The slitting process may be performed by a known method other than the rotary blade.

[0118] The unwinding tension and the winding tension when peeling one of the first base material and the second base material may be, for example, 5 to 30 N / m. The slitting process may be performed by a known method.

[0119] In the slitting process, the laminate may be cut so that the width of the adhesive film for circuit connection is 0.5 to 3 mm, 0.8 to 2.0 mm, or 1.0 to 1.5 mm.

[0120] In FIGS. 7 and 8, after peeling the second base material 21 from the laminate A54, the adhesive film 55 for circuit connection is slit to obtain the adhesive film 56 for circuit connection. However, after slitting the laminate A54, the second base material 21 may be peeled off to obtain the adhesive film 56 for circuit connection.

[0121] In FIGS. 7 and 8, the adhesive film 56 for circuit connection is wound around the winding core 110 so that the first base material 11 is on the outside. However, the adhesive film 56 for circuit connection may be wound around the winding core so that the first base material 11 is on the inside. Also, in FIGS. 7 and 8, the second base material 21 is peeled off from the laminate A54. However, instead of peeling off the second base material 21, the first base material 11 may be peeled off to use as the adhesive film for circuit connection. In this case, the adhesive film for circuit connection may be wound around the winding core so that the second base material 21 is on the outside, or may be wound around the winding core so that the second base material 21 is on the inside.

[0122] When the laminate before peeling one of the first base material and the second base material is cut to the width of the adhesive film for circuit connection, one of the first base material and the second base material may be peeled off from the laminate and wound around the winding core.

[0123] According to the method for manufacturing the wound body of the adhesive film for circuit connection according to the present embodiment, in step S2, since only one peeling of the laminate from which one of the first base material and the second base material has been peeled off is provided, in the process from preparing the roll-shaped raw material in step S1 to obtaining the wound body of the adhesive film for circuit connection, it is possible to suppress the state on the side opposite to the base material side of the adhesive layer from becoming too rough. Thereby, it is possible to prevent the capturing property of the conductive particles from deteriorating, and it is possible to obtain a wound body of the adhesive film for circuit connection having a desired conductive particle capturing property. When peeling the second base material in step S2, it is possible to more effectively prevent the capturing property of the conductive particles from deteriorating. Also, when peeling the first base material in step S2, if the thickness of the adhesive layer is 3 μm or less, it is possible to more effectively prevent the capturing property of the conductive particles from deteriorating.

Example

[0124] Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the examples.

[0125] <Production of Conductive Particles> Ni plating was applied to the surface of the plastic core, and replacement plating with Pd was applied to the outermost surface to obtain conductive particles (average particle size: 3.2 μm).

[0126] <Preparation of Thermosetting Compositions for the First Adhesive Layer and the Second Adhesive Layer> The components shown below were mixed in the blending amounts (parts by mass) shown in Table 1 to prepare a composition for the first adhesive layer and compositions (1) and (2) for the second adhesive layer.

[0127] (A) Component: Thermosetting resin component (A1) Component: Cationic polymerizable compound A1-1: ETERNACOLL OXBP (oxetane compound, manufactured by Ube Industries, Ltd.) A1-2: EHPE3150 (alicyclic epoxy compound, manufactured by Daicel Corporation) A1-3: CEL2021P (alicyclic epoxy compound, manufactured by Daicel Corporation) A1-4: JER1007 (epoxy compound, manufactured by Mitsubishi Chemical Corporation) (A2) Component: At the start of thermal cationic polymerization A2: CXC-1821 (N-(p-methoxybenzyl)-N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate, manufactured by King Industries) (B) Component: Thermoplastic resin B1: FX-293 (phenoxy resin, manufactured by Nippon Steel Chemical & Material Co., Ltd.) B2: YP-70 (phenoxy resin, manufactured by Nippon Steel Chemical & Material Co., Ltd.) (C) Component: Coupling agent C1: SH-6040 (3-glycidoxypropyltrimethoxysilane, manufactured by Toray Dow Corning Co., Ltd.) (D) Component: Filler D1: Admafin SE2050 (silica fine particles, manufactured by Admatechs Co., Ltd.) D2: Aerosil R805 (silica fine particles, manufactured by Evonik Industries AG) (Component (E): Conductive particles E1: Conductive particles prepared as described above (Component (F): Photo-curable resin component (Component (F1): Radical polymerizable compound F1-1: VR-90 (bisphenol A type epoxy (meth)acrylate (bifunctional) (vinyl ester resin), manufactured by Showa Denko K.K.) F1-2: A-1000 (polyethylene glycol diacrylate (bifunctional), manufactured by Shin-Nakamura Chemical Co., Ltd.) (Component (F2): Photo-radical polymerization initiator F2: Irgacure907 (compound having an α-aminoalkylphenone structure, manufactured by BASF)

[0128]

Table 1

[0129] <Preparation of substrates> Substrate A (thickness: 50 μm, material: white PET) and substrate B (thickness: 50 μm, material: PET) having the arithmetic mean height (Sa) and root mean square height (Sq) of the surfaces on the adhesive layer side and the back side shown in Table 2 were prepared respectively.

[0130]

Table 2

[0131] [Preparation of roll-shaped raw fabric A1] <Preparation of laminate (1) (first substrate and first adhesive layer provided thereon)> The composition for the first adhesive layer was applied onto the adhesive layer side surface of the base material A using a coating device, and then hot air drying was carried out at 60°C for 3 minutes to form a first adhesive layer (a layer composed of the composition for the first adhesive layer) with a thickness of 6 μm. Here, the thickness was measured by the method for measuring the thickness of the adhesive layer described later. Through the above operations, a laminate (1) having a first adhesive layer on a first base material was obtained.

[0132] <Production of laminate (2) (a second base material and a second adhesive layer provided thereon)> The composition (1) for the second adhesive layer was applied onto the adhesive layer side surface of the base material B using a coating device. Next, hot air drying was carried out at 60°C for 3 minutes to form a layer composed of the composition (1) for the second adhesive layer with a thickness (thickness after drying) of 3 μm on the second base material. Here, the thickness was measured by the method for measuring the thickness of the adhesive layer described later. Next, the layer composed of the composition (1) for the second adhesive layer was subjected to UV irradiation using a metal halide lamp so that the integrated light quantity became 1000 mJ / cm 2 to polymerize the component (F1). Thereby, the composition (1) for the second adhesive layer was cured to form a second adhesive layer. Through the above operations, a laminate (2) having a second adhesive layer on a second base material was obtained. The conductive particle density at this time was about 18000 particles (pcs) / mm 2 was.

[0133] The laminate (1) and the laminate (2) were arranged such that their respective adhesive layers faced each other, and while heating at 40°C together with their respective base materials, they were laminated using a roll laminator. Thereby, a laminate A having a first base material, a first adhesive layer, a second adhesive layer, and a second base material in this order was produced. The obtained laminate A1 was wound around a winding core such that the first base material was on the outside to obtain a roll stock A1 with a width of 300 mm.

[0134] [Production of roll stock A2] Using the composition (2) for the second adhesive layer instead of the composition (1) for the second adhesive layer, and instead of performing UV irradiation at 1000 mJ / cm 2 performing it at 2000 mJ / cm2 The roll-like base web A2 was produced in the same manner as the production of the roll-like base web A1, except that it was carried out by

[0135] [Production of a wound body of an adhesive film for circuit connection] (Example 1) The laminate A1 was unwound from the roll-like base web A1 and cut by roll-to-roll slitting equipment so as to have a width of about 20 mm, and then wound around a winding core with the first base material on the outside to obtain a wound body A. After the obtained wound body A was unwound and the second base material was peeled off, it was cut by roll-to-roll slitting equipment so as to have a width of about 2 mm. After cutting, it was wound around a winding core with the first base material on the outside to obtain a wound body of an adhesive film for circuit connection.

[0136] (Example 2) A wound body of an adhesive film for circuit connection was obtained in the same manner as in Example 1, except that the roll-like base web A2 was used instead of the roll-like base web A1.

[0137] (Comparative Example 1) The laminate A1 was unwound from the roll-like base web A1, and after the second base material was peeled off, it was wound around a winding core with the first base material on the outside to obtain a wound body. Next, this wound body was unwound and cut by roll-to-roll slitting equipment so as to have a width of about 20 mm, and then wound around a winding core with the first base material on the outside to obtain a wound body. The obtained wound body was unwound and cut by roll-to-roll slitting equipment so as to have a width of about 2 mm. After cutting, it was wound around a winding core with the first base material on the outside to obtain a wound body of an adhesive film for circuit connection.

[0138] (Comparative Example 2) A wound body of an adhesive film for circuit connection was obtained in the same manner as in Comparative Example 1, except that the roll-like base web A2 was used instead of the roll-like base web A1.

[0139] The following evaluations were carried out on the adhesive films for circuit connection unwound from the wound bodies obtained in Example 1 and 2, and Comparative Example 1 and 2.

[0140] [Measurement of the Thickness of the Adhesive Layer] Two sheets of circuit connection adhesive film were sandwiched between two pieces of glass (thickness: about 1 mm), and after casting with a resin composition consisting 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 Tech Co., Ltd.), cross-section polishing was performed using a polishing machine, and the thicknesses of the first adhesive layer and the second adhesive layers (1) and (2) were measured using a scanning electron microscope (SEM, trade name: SE-8020, manufactured by Hitachi High-Technologies Corporation).

[0141] [Evaluation of Particle Capturing Property] An IC chip with bump electrodes arranged (outer dimensions 2 mm × 20 mm, thickness 0.3 mm, area of bump electrodes 840 μm 2 (length 70 μm × width 12 μm), space between bump electrodes 12 μm, height of bump electrodes 8 μm), and a glass substrate (thickness 0.3 mm) provided with a SiN / Al film were prepared. After aligning the bump electrodes of the IC chip with the circuit electrodes of the glass substrate, the first base material was peeled off from the circuit connection adhesive film, and the IC chip and the circuit electrodes were sandwiched with the second adhesive layer facing the circuit board, and heated and pressurized for 5 seconds under the conditions of a measured maximum reachable temperature of 210 °C and a pressure in terms of area conversion at the bump electrodes of 27 MPa to obtain a circuit connection structure. Sixty bumps of the electrodes of the above circuit connection body were selected, and the number of indentations observed with a microscope was measured. From the average (Ave) and standard deviation (σ) of the measured number of indentations, the number of captures (pieces / 840 μm 2 ) was calculated according to the following formula. Number of captures = Ave - 3σ … (formula)

[0142] [Evaluation of Connection Characteristics] For the circuit connection structures immediately after fabrication and after the reliability test obtained in the same manner as the evaluation of the above-described particle capture number, the resistance values between the opposing electrodes (between the bump electrode and the circuit electrode) of each circuit connection structure were measured by the four-terminal measurement method using a multimeter MLR21 (manufactured by Kusumoto Chemical Co., Ltd.), and the connection resistance was evaluated by comparing the average values of the measurement values at 14 locations. The resistance value obtained immediately after fabrication was defined as the initial resistance value, and the resistance value after the reliability test was defined as the post-reliability resistance value. The reliability test was performed by storing the circuit connection structure at a temperature of 110°C and a humidity of 85% RH for 64 hours.

[0143] [Evaluation of the Surface Shape of the Second Adhesive Layer of the Circuit Connection Adhesive Film] Using a laser microscope OLS4100 (manufactured by Olympus), the second adhesive layer side of the circuit connection adhesive film was photographed, and the parameters of the surface roughness of the second adhesive layer were calculated using the attached surface analysis software. As the parameters of the surface roughness, the arithmetic mean height (Sa), the root mean square height (Sq), the skewness (Ssk), and the kurtosis (Sku) were calculated. The photographing was performed at a magnification of 100 times with an objective lens. Also, in the attached surface analysis software, regarding the cut-off wavelength during analysis, λs was set to 25 μm, and λc and λf were not set.

[0144]

Table 3

[0145] As shown in Table 3, when comparing the circuit connection adhesive films unwound from the wound bodies obtained in Examples 1 and 2 and Comparative Examples 1 and 2, since the number of captured particles in Examples 1 and 2 was large, it was shown that the circuit connection adhesive films unwound from the wound bodies obtained in Examples 1 and 2 were excellent in particle capture performance. Also, since the initial resistance values and the post-reliability resistance values in Examples 1 and 2 were small, it was shown that the circuit connection adhesive films unwound from the wound bodies obtained in Examples 1 and 2 were excellent in connection characteristics. Further, it was also confirmed that the circuit connection adhesive films of Examples 1 and 2, in which Sq on the surface of the second adhesive layer was in the range of 0.005 to 0.1 μm, were excellent in particle capture performance as compared with the circuit connection adhesive films of Comparative Examples 1 and 2, in which Sq on the surface of the second adhesive layer exceeded 0.1 μm.

Explanation of Reference Numerals

[0146] 1…Conductive particle, 2…Adhesive component, 10…Laminate having a first base material and a first adhesive layer provided thereon, 11…First base material, 12…First adhesive layer, 20…Laminate having a second base material and a second adhesive layer provided thereon, 21…Second base material, 22…Second adhesive layer, 40…Rolled raw material, 42…Wound body A, 52, 54…Laminate A, 55, 56, 58, 60…Circuit connection adhesive film, 92…Slitting blade, 94…Rotating blade, 100…Wound body of circuit connection adhesive film, 101…Base material, 102, 102a, 102b…Adhesive layer, 110…Winding core.

Claims

1. A method for manufacturing a wound body of an adhesive film for circuit connection, comprising a base material, a first adhesive layer containing a thermosetting composition provided on the base material, and a second adhesive layer containing conductive particles and a thermosetting composition, a step S1 of preparing a roll-shaped raw web obtained by winding a laminate having a first base material, a first adhesive layer containing a thermosetting composition, a second adhesive layer containing conductive particles and a thermosetting composition, and a second base material in this order; a step S2 of obtaining a wound body of the adhesive film for circuit connection by winding the laminate unwound from the roll-shaped raw web through a process including cutting the laminate to a predetermined width and peeling one of the first base material and the second base material, and then winding it around a winding core, The method for manufacturing a wound body of an adhesive film for circuit connection, wherein in the step S2, winding the laminate from which one of the first base material and the second base material has been peeled is provided only once.

2. The method for manufacturing a wound body of an adhesive film for circuit connection according to claim 1, wherein in the step S2, the second base material is peeled off.

3. The method for manufacturing a wound body of an adhesive film for circuit connection according to claim 1, wherein the step S2 includes cutting the laminate from which one of the first base material and the second base material has been peeled to a width of 0.5 to 3 mm.

4. A wound body in which an adhesive film for circuit connection having a base material and an adhesive layer provided on the base material is wound around a winding core, wherein the adhesive layer includes a first adhesive layer containing a thermosetting composition and a second adhesive layer containing conductive particles and a thermosetting composition, The wound body of the adhesive film for circuit connection, wherein when the adhesive film for circuit connection is unwound from the wound body, the root mean square height of the surface of the adhesive layer on the side opposite to the base material side is 0.005 to 0.1 μm.

5. The wound body according to claim 4, wherein when the adhesive film for circuit connection is unwound from the wound body, the kurtosis of the surface of the adhesive layer on the side opposite to the base material side is 2.8 to 4.

6. The wound body according to claim 4 or 5, wherein the second adhesive layer further contains a cured product of a photocurable resin component.

7. The wound body according to claim 4 or 5, wherein the adhesive film for circuit connection has the base material, the first adhesive layer, and the second adhesive layer in this order.

8. An original web for forming an adhesive film for circuit connection, comprising a wound body obtained by winding a laminate having, in this order, a first base material, a first adhesive layer containing a thermosetting composition, a second adhesive layer containing conductive particles and a thermosetting composition, and a second base material, around a winding core.

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