Method for manufacturing a roll of adhesive film for circuit connection and roll of adhesive film for circuit connection

Abstract

A method for manufacturing a roll of an adhesive film for circuit connection is a method for manufacturing a roll of an adhesive film for circuit connection having a base material and a first adhesive layer provided on the base material and containing a thermosetting composition and a second adhesive layer containing electrically conductive particles and a thermosetting composition, the method including: Step S1, preparing a roll-shaped raw material of a roll laminate having a first base material, a first adhesive layer containing a thermosetting composition, a second adhesive layer containing electrically conductive particles and a thermosetting composition, and a second base material in this order; and Step S2, after the laminate rolled out from the roll-shaped raw material is subjected to a process including a step of cutting to a prescribed width and a step of peeling one of the first base material and the second base material, winding the laminate on which one of the first base material and the second base material is peeled on a core, thereby obtaining a roll of an adhesive film for circuit connection, in Step S2, the step of winding the laminate from which one of the first base material and the second base material is peeled is provided only once.

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 Technology

[0002] In the past, various adhesive materials have been used for circuit connections. For example, as an adhesive material for connecting liquid crystal displays to tape packages (TCP), flexible printed circuit boards (FPCs) to TCPs, or FPCs to printed circuit boards, anisotropic conductive adhesive films with conductive particles dispersed in the adhesive are used for circuit connections.

[0003] In recent years, the field of precision electronic equipment has seen continuous development towards higher circuit density, resulting in extremely narrow electrode widths and spacing. When connecting such circuits using adhesive films for circuit connections, it is essential to ensure insulation between adjacent circuit electrodes and to trap more conductive particles between opposing circuit electrodes to reduce connection resistance.

[0004] Techniques for improving the conductive particle trapping ability of adhesive films containing conductive particles have been studied to date. For example, adhesive films for circuit connection having two layers, a conductive adhesive layer containing conductive particles and an insulating adhesive layer, have been proposed (for example, see Patent Document 1 below).

[0005] Previous technical documents

[0006] Patent documents

[0007] Patent Document 1: International Publication No. 2019-050012 Summary of the Invention

[0008] The technical problem to be solved by the invention

[0009] Adhesive films for circuit connections are typically used in such a way that a laminate of a substrate such as polyethylene terephthalate (PET) film, on which an adhesive layer is provided, is cut into strips (or tapes) of a width suitable for the application. These adhesive films for circuit connections are supplied as a wound body (e.g., a spool) wound onto a core.

[0010] The aforementioned adhesive film for circuit connection with multiple adhesive layers is also supplied and used as a winding body. However, through the research of the inventors, it has been found that the conductive particle trapping property of the adhesive film for circuit connection varies depending on the manufacturing process of the winding body.

[0011] Therefore, the main objective of this invention is to provide a wound body of an adhesive film for circuit connection having the desired conductive particle trapping properties and a method for manufacturing the same.

[0012] means for solving technical problems

[0013] The present invention provides the invention described in [1] to [8] below.

[0014] [1] A method for manufacturing a wound body of an adhesive film for circuit connection, comprising: step S1, preparing a roll of raw material formed by winding a laminate, the laminate having a first substrate, a first adhesive layer containing a thermosetting composition disposed on the substrate, a second adhesive layer containing conductive particles and a thermosetting composition, and a second substrate in sequence; and step S2, after the laminate wound from the roll of raw material is processed including a step of cutting to a predetermined width and a step of peeling off one of the first substrate and the second substrate, the laminate is wound onto a core to obtain the wound body of the adhesive film for circuit connection, wherein in step S2, only one step of winding the laminate after peeling off one of the first substrate and the second substrate is performed.

[0015] [2] The method for manufacturing a winding of an adhesive film for circuit connection according to [1], wherein the second substrate is peeled off in step S2.

[0016] [3] The method for manufacturing a winding of an adhesive film for circuit connection according to [1] or [2], wherein step S2 includes the step of cutting the laminate, from which one of the first substrate and the second substrate has been peeled off, into a width of 0.5 to 3 mm.

[0017] [4] A winding body for an adhesive film for circuit connection, wherein the winding body is a winding body having a substrate and an adhesive layer disposed on the substrate wound on a core, wherein the adhesive layer includes a first adhesive layer comprising a thermosetting composition and a second adhesive layer comprising conductive particles and a thermosetting composition, and when the adhesive film for circuit connection is wound out from the winding body, the root mean square height of the surface of the adhesive layer opposite to the substrate side is 0.005 to 0.1 μm.

[0018] [5] According to the winding body described in [4], when the adhesive film for circuit connection is wound out from the winding body, the kurtosis of the surface of the adhesive layer opposite to the substrate side is 2.8 to 4.

[0019] [6] The winding according to [4] or [5], wherein the second adhesive layer further contains a cured product of a photocurable resin component.

[0020] [7] The winding body according to any one of [4] to [6], wherein the adhesive film for circuit connection has the substrate, the first adhesive layer and the second adhesive layer in sequence.

[0021] [8] A raw material for forming an adhesive film for circuit connection, comprising a winding body for winding a laminate onto a core, the laminate having in sequence a first substrate, a first adhesive layer comprising a thermosetting composition, a second adhesive layer comprising conductive particles and a thermosetting composition, and a second substrate.

[0022] According to the manufacturing method described in [1], it is possible to manufacture a roll of adhesive film for circuit connection with the desired conductive particle trapping properties. The reason for this effect is as follows: In the process from preparing the roll of raw material to obtaining the roll of adhesive film for circuit connection, by performing the step of taking the laminate after peeling off one of the first substrate and the second substrate only at the end of step S2, it is possible to prevent the surface of the adhesive layer on the side opposite to the substrate side of the bonding surface of the circuit component from becoming too rough when the adhesive film for circuit connection is rolled out from the roll, thereby preventing a decrease in the trapping properties of conductive particles. In addition, in step S2, if one or more of the following processes are performed on the laminate, such as cutting to a specified width, foreign object inspection, and light irradiation, these processes can be performed on the laminate rolled out with the adhesive layer disposed between the two substrates, or on the laminate after peeling off one of the first substrate and the second substrate.

[0023] The winding of the adhesive film for circuit connection according to [4] has the aforementioned specific root mean square height on the surface of the adhesive layer that becomes the attachment surface of the circuit component opposite to the substrate side, thus enabling it to have the desired conductive particle trapping properties.

[0024] Invention Effects

[0025] According to the present invention, it is possible to provide a winding of an adhesive film for circuit connection having desired conductive particle trapping properties and a method thereof. Attached Figure Description

[0026] Figure 1 This is a schematic cross-sectional view showing one embodiment of a wound body of adhesive film for circuit connection.

[0027] Figure 2 This is an enlarged schematic cross-sectional view showing one embodiment of the adhesive film used for circuit connection.

[0028] Figure 3 This is an enlarged schematic cross-sectional view showing another embodiment of the adhesive film for circuit connection.

[0029] Figure 4This is a perspective view of an example of step S1 in one embodiment of a method for manufacturing a wound body of an adhesive film for circuit connection.

[0030] Figure 5 It is used for explanation Figure 4 An enlarged schematic cross-sectional view of process S1 shown.

[0031] Figure 6 This is a perspective view of an example of step S2 in one embodiment of a method for manufacturing a wound body of an adhesive film for circuit connection.

[0032] Figure 7 This is a perspective view of an example of step S2 in one embodiment of a method for manufacturing a wound body of an adhesive film for circuit connection.

[0033] Figure 8 It is used for explanation Figure 7 An enlarged schematic cross-sectional view of an example of process S2 shown. Detailed Implementation

[0034] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, the same or equivalent parts are labeled with the same symbols, and repeated descriptions are omitted. The present invention is not limited to the following embodiments.

[0035] In this specification, the numerical range indicated by "~" represents a range encompassing the minimum and maximum values ​​recorded before and after the "~". Within the numerical range described in stages in this specification, the upper or lower limit of a certain stage's numerical range can be replaced by the upper or lower limit of other stages' numerical ranges. Furthermore, within the numerical range described in this specification, the upper or lower limit of the numerical range can also be replaced by the values ​​shown in the embodiments. Moreover, the individually described upper and lower limits can be arbitrarily combined. In expressions such as "A~B" for numerical ranges, the values ​​A and B at both ends are included within the numerical range as the lower and upper limits, respectively. In this specification, expressions such as "10 or more" refer to "10" and "values ​​exceeding 10," even if the values ​​differ. Similarly, expressions such as "10 or less" refer to "10" and "values ​​less than 10," even if the values ​​differ. Furthermore, in this specification, "(meth)acrylate" refers to at least one of acrylates and their corresponding methacrylates. The same applies to other similar expressions such as "(meth)acryloyl" and "(meth)acrylic acid". Furthermore, "A or B" can include either A or B, or both. Moreover, unless otherwise specified, the materials exemplified below can be used alone or in combination of two or more. When multiple substances constituting components are present in the composition, unless otherwise specified, the content of each component in the composition refers to the total amount of those multiple substances present in the composition.

[0036] <Wrapped body of adhesive film for circuit connection>

[0037] The circuit connection adhesive film of this embodiment is a winding body in which a circuit connection adhesive film having a substrate and an adhesive layer disposed on the substrate is wound on a core. The adhesive layer includes a first adhesive layer comprising a thermosetting composition and a second adhesive layer comprising conductive particles and a thermosetting composition. The circuit connection adhesive film can be wound on the core with the substrate on the outer side or with the substrate on the inner side.

[0038] The winding body of the adhesive film for circuit connection according to this embodiment can be used, for example, in a method for manufacturing a circuit connection structure. The method for manufacturing a circuit connection structure includes the following steps: placing an adhesive layer from the adhesive film for circuit connection wound from the winding body between a first circuit component having a first electrode (circuit electrode) and a second circuit component having a second electrode (circuit electrode); and then thermally pressing the first circuit component and the second circuit component together 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.

[0039] The above method may include: a lamination process, in which an adhesive film for circuit connections, wound from a winding body, is laminated onto the first circuit component in a substrate state and in a manner where the adhesive layer is in contact with the first circuit component; a peeling process, in which the substrate is peeled off from the adhesive film for circuit connections attached to the first circuit component; and a heating and pressurizing process, in which a second circuit component is disposed on the first circuit component with the laminated adhesive layer in a manner where the first electrode and the second electrode are facing each other, the adhesive layer is heated, and the first circuit component and the second circuit component are pressurized in the direction where the first electrode and the second electrode are facing each other. Furthermore, the lamination process and the peeling process may be modified to be a process in which the lamination is performed after or simultaneously with the peeling of the substrate, in a manner that ensures a tight seal between the adhesive layer and the first circuit component.

[0040] There are no particular restrictions on the lamination method; roller laminators, diaphragm laminators, vacuum roller laminators, and vacuum diaphragm laminators can be used. Temporary lamination can be followed by heat pressing to achieve proper bonding.

[0041] As a heating mechanism, a known hot pressing device can be used. As a pressurizing mechanism, a known hot pressing device can be used.

[0042] Figure 1 This is a cross-sectional view showing an example of a wound body of an adhesive film for circuit connection according to this embodiment. Figure 1 The wound body 100 shown has the following structure: an adhesive film 60 for circuit connection, having a substrate 101 and an adhesive layer 102 disposed on the substrate 101, is wound around the outer surface F1 of the core 110. The adhesive film 60 for circuit connection is wound such that the adhesive layer 102 faces the core 110 and the substrate 101 faces outward. In the wound body 100, the inner surface S2 of the adhesive layer 102 contacts the outer surface F1 of the core 110 or the outer surface S1 of the substrate 101.

[0043] As the substrate 101, for example, a substrate (e.g., a film) composed of polyolefins such as stretched polypropylene (OPP), polyethylene terephthalate (PET), polyethylene naphthalate, polyethylene terephthalate, polyethylene terephthalate, polybutylene terephthalate, polyethylene, polypropylene, polyacetate, polycarbonate, polyphenylene sulfide, polyamide, polyimide, cellulose, ethylene-vinyl acetate copolymer, polyvinyl chloride, polyvinylidene chloride, synthetic rubber, and liquid crystal polymers can be used. The substrate can contain any filler material. Examples of fillers include oxides such as titanium dioxide. Furthermore, a release treatment or plasma treatment can be performed on the surface of the substrate.

[0044] The winding body 100 of the adhesive film for circuit connection can be used as a spool. The structure of the spool is not particularly limited, and a known structure can be used. For example, it can include: a core 110; a pair of side plates disposed opposite each other at both ends of the core; and the winding body 100 of the adhesive film for circuit connection according to this embodiment, wound around the core. Furthermore, in Figure 1 In this case, the adhesive film 60 for circuit connection (i.e., the adhesive films 56 and 58 for circuit connection) is wound around the core 110 with the substrate 101 facing outward. However, when the adhesive film 60 for circuit connection is wound around the core 110 with the substrate 101 facing inward, the wound body of the adhesive film for circuit connection can also be used as a spool body.

[0045] The thickness of the adhesive film used for circuit connections (in) Figure 1 The total thickness of the substrate 101 and the adhesive layer 102 can 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, or less than 100.0 μm, less than 80.0 μm, less than 70.0 μm, less than 60.0 μm, or less than 40.0 μm.

[0046] The thickness of the adhesive layer in the adhesive film for circuit connection (in) Figure 1 The thickness of the adhesive layer 102 can be, for example, 2.0 μm or more, 5.0 μm or more, 6.0 μm or more, or 7.0 μm or more, or less than 40.0 μm, less than 20.0 μm, less than 10.0 μm, or less than 3.0 μm.

[0047] From the viewpoint of easily capturing conductive particles between electrodes, when the adhesive film for circuit connection is wound off the winding body, the surface of the adhesive layer opposite to the substrate side (in...) Figure 1The root mean square height (Sq) of the adhesive layer 102 (S2 surface) can be 0.005 to 0.1 μm. Furthermore, from the viewpoint of easily winding the adhesive film for circuit connection from the winding body, Sq can be 0.005 μm or more, or 0.001 μm or more; from the viewpoint of easily capturing conductive particles between electrodes, it can be 0.1 μm or less, or 0.05 μm or less. Moreover, by satisfying the above-mentioned upper limit value for Sq, the ease of peeling the adhesive film from the substrate after hot-pressing the adhesive film for circuit connection to circuit components, etc., without peeling off the substrate (hereinafter sometimes referred to as "substrate reworkability") can be improved.

[0048] Circuit connection structures obtained using adhesive films for circuit connections sometimes require the characteristic that the connection resistance between the connected electrodes does not easily increase even after reliability testing under high temperature and high humidity conditions (e.g., temperature 85°C and humidity 85%) (hereinafter sometimes referred to as "connection reliability"). From the viewpoint of connection reliability and conductive particle trapping, when the roll of the adhesive film for circuit connections is wound off, the surface of the adhesive layer opposite to the substrate side (in...) Figure 1 The ku value of the S2 surface of the adhesive layer 102 can be 2.8 to 4 or 2.9 to 3.5.

[0049] From the perspective of connection reliability and conductive particle trapping, when the adhesive film for circuit connection is wound off from the winding body, the surface of the adhesive layer opposite to the substrate side (in...) Figure 1 The arithmetic mean height (Sa) of the S2 surface of the adhesive layer 102 can be 0.005–0.1 μm, 0.005–0.05 μm, or 0.005–0.03 μm.

[0050] From the perspective of connection reliability and conductive particle trapping, when the adhesive film for circuit connection is wound off from the winding body, the surface of the adhesive layer opposite to the substrate side (in...) Figure 1 The skewness (Ssk) of the S2 surface of the adhesive layer 102 can be -0.9 to 0, -0.8 to 0, or -0.7 to 0.

[0051] In addition, Figure 1 In the circuit connection adhesive film 60, the substrate 101 is wound on the core 110 with the adhesive film 60 wound on the core 110 with the adhesive film 60 wound on the core 110 with the substrate 101 facing inward. However, when the adhesive film 60 is wound on the core 110 with the adhesive film 60 wound on the core 110 with the adhesive film 60, the values ​​of Sq, Sku, Sa and Skk on the surface of the adhesive film can be the same as the values ​​mentioned above.

[0052] Sq, Sku, Sa, and Ssk can be determined, for example, by the methods described in the embodiments. Specifically, the surface of the adhesive film for circuit connections rolled out of the winding body, opposite to the substrate side of the adhesive layer, can be photographed using a laser microscope OLS4100 (manufactured by Olympus Corporation), and the surface roughness parameters can be calculated using the accompanying surface analysis software. Furthermore, the image can be taken at 100x magnification using an objective lens, and in the accompanying surface analysis software, the cutoff wavelength λs can be set to 25 μm, or λc and λf can be left unset.

[0053] In the winding body of the adhesive film for circuit connection in this embodiment, from the viewpoint of easily obtaining connection reliability and conductive particle trapping, when the adhesive film for circuit connection is wound out of the winding body, the surface of the substrate opposite to the adhesive layer side (in) Figure 1 The root mean square height (Sq) of the S1 surface of the substrate 101 can be 0.005–0.3 μm, 0.005–0.1 μm, or 0.005–0.01 μm. Furthermore, by making Sq meet the above ranges, the reworkability of the substrate can be easily obtained.

[0054] In the winding body of the adhesive film for circuit connection in this embodiment, from the viewpoint of easily obtaining connection reliability and conductive particle trapping, when the adhesive film for circuit connection is wound out of the winding body, the surface of the substrate opposite to the adhesive layer side (in) Figure 1 The arithmetic mean height (Sa) of the S1 surface of the substrate 101 can be 0.005–0.2 μm, 0.005–0.1 μm, or 0.005–0.01 μm. Furthermore, by making Sa meet the above ranges, the reworkability of the substrate can be easily obtained.

[0055] In addition, Figure 1 In the circuit connection adhesive film 60, the substrate 101 is wound on the core 110 in such a way that the adhesive film 60 is wound on the core 110 in such a way that the substrate 101 is wound on the core 110, but when the adhesive film 60 is wound on the core 110 in such a way that the substrate 101 is wound on the core, the Sq and Sa of the above-mentioned surface of the substrate can also be the same as the above-mentioned numerical range.

[0056] Hereinafter, the adhesive film for circuit connection of this embodiment will be described in further detail with reference to the accompanying drawings.

[0057] Figure 2 This is an enlarged cross-sectional view showing an example of an adhesive film used for circuit connections. Figure 2The circuit connection adhesive film 56 shown includes: a substrate 11; and an adhesive layer 102a, comprising, sequentially from the substrate 11 side, a first adhesive layer 12 comprising a thermosetting composition disposed on one side of the substrate 11, and a second adhesive layer 22 comprising an adhesive component 2 containing a plurality of conductive particles 1 and a thermosetting composition. Additionally, in Figure 2 In the circuit connection adhesive film 56 shown, a portion of the conductive particles 1 protrudes from the surface of the second adhesive layer 22 (e.g., protruding towards the first adhesive layer 12), but the conductive particles 1 can also be entirely embedded in the second adhesive layer 22 so that the conductive particles 1 do not protrude from the surface of the second adhesive layer 22. In the circuit connection adhesive film 56, the substrate 11 is peeled off during use.

[0058] Figure 3 This is an enlarged cross-sectional view showing another example of an adhesive film used for circuit connections. Figure 3 The circuit connection adhesive film 58 shown includes: a substrate 21; and an adhesive layer 102b, comprising, sequentially from the substrate 21 side, a second adhesive layer 22 comprising an adhesive component 2 containing a plurality of conductive particles 1 and a thermosetting composition, and a first adhesive layer 12 comprising a thermosetting composition, disposed on one side of the substrate 21. Additionally, in Figure 3 In this process, a portion of the conductive particle 1 protrudes from the surface of the second adhesive layer 22 (e.g., protruding towards the first adhesive layer 12), but the conductive particle 1 can also be entirely embedded in the second adhesive layer 22 so that the conductive particle 1 does not protrude from the surface of the second adhesive layer 22. In the adhesive film 58 for circuit connection, the substrate 21 is peeled off during use.

[0059] In the above-described method for manufacturing the circuit connection structure, the circuit connection adhesive film 56 can be laminated onto the first circuit component in such a way that the second adhesive layer 22 contacts the first circuit component, and the circuit connection adhesive film 58 can be laminated onto the first circuit component in such a way that the first adhesive layer 12 contacts the first circuit component.

[0060] Substrate 11 and 21 can be the same substrate as described above. The values ​​Sq and Sa of the surfaces of substrate 11 and 21 opposite to the adhesive layer side can also be the same as those described above.

[0061] In the adhesive film 56 for circuit connection, the surface of the second adhesive layer 22 opposite to the substrate 11 can satisfy any one of the conditions Sq, Sku, Sa, and Ssk described above. In the adhesive film 58 for circuit connection, the surface of the first adhesive layer 12 opposite to the substrate 21 can satisfy any one of the conditions Sq, Sku, Sa, and Ssk described above.

[0062] Next, the components constituting the first adhesive layer 12 and the second adhesive layer 22 will be described.

[0063] (First adhesive layer)

[0064] 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 cured by heat in at least a portion and may contain a thermosetting resin component (hereinafter, sometimes referred to as "component (A)").

[0065] [(A) Ingredient: Thermosetting resin component]

[0066] (A) There are no particular restrictions as long as it is a resin component that is cured by heat. For example, it may contain a cationic polymerizable compound (hereinafter, sometimes referred to as "(A1) component") and a thermal cationic polymerization initiator (hereinafter, sometimes referred to as "(A2) component"). (A) component may be a component consisting of (A1) component and (A2) component.

[0067] (A1) Composition: Cationic polymeric compound

[0068] Component (A1) is a compound that crosslinks with component (A2) through a thermal reaction. Furthermore, component (A1) refers to a compound that does not have a free radical polymerizable group that reacts with a free radical, and component (A1) is not included in component (F1). Examples of components (A1) include oxetane compounds, epoxy compounds, and other compounds having cyclic ether groups. Component (A1) can be used alone or in combination. From the viewpoint of further improving the reduction effect of connection resistance and achieving better connection reliability, component (A1) may, for example, include at least one compound selected from the group consisting of oxetane compounds and alicyclic epoxy compounds. From the viewpoint of easily obtaining the desired melt viscosity, component (A1) may include both at least one oxetane compound and at least one alicyclic epoxy compound.

[0069] As a component of (A1), the oxetane compound can be used without particular restriction as long as it has an oxetyl group and does not have a free radical polymerizable group. Commercially available oxetane compounds include, for example, ETERNACOLL OXBP (trade name, 4,4'-bis[(3-ethyl-3-oxetyl)methoxymethyl]biphenyl, manufactured by UBECorporation), OXSQ, OXT-121, OXT-221, OXT-101, and OXT-212 (trade name, manufactured by TOAGOSEI CO., LTD.). These compounds can be used individually or in combination.

[0070] The alicyclic epoxy compound used as component (A1) can be used without particular restriction as long as it has an alicyclic epoxy group (e.g., epoxycyclohexyl) and does not have a free radical polymerizable group. Commercially available alicyclic epoxy compounds include, for example, EHPE3150, EHPE3150CE, CELLOXIDE8010, CELLOXIDE2021P, and CELLOXIDE2081 (trade name, manufactured by Daicel Corporation). These can be used individually or in combination.

[0071] (A2) Component: Thermal cationic polymerization initiator

[0072] (A2) is a thermal polymerization initiator that initiates polymerization by generating acids, etc., upon heating. (A2) can be a salt compound composed of cations and anions. Examples of (A2) components include those containing BF4. - BR4 - (R represents a phenyl group substituted with two or more fluorine atoms or two or more trifluoromethyl groups.) PF6 - SbF6 - AsF6 - Onion salts such as anionic sulfonium salts, phosphonium salts, ammonium salts, diazonium salts, iodine salts, aniline onion salts, and pyridinium onion salts are examples. These can be used individually or in combination.

[0073] From the perspective of preservation stability, component (A2) could be, for example, an anion containing boron as a constituent element, namely BF4. - Or BR4 - (R represents a phenyl group substituted with two or more fluorine atoms or two or more trifluoromethyl groups.) The anion containing boron as a constituent element can be BR4-, and more specifically, tetra(pentafluorophenyl)borate.

[0074] The onium salt as component (A2) has resistance to substances that may cause curing hindrance to cationic curing, and therefore can be, for example, an aniline onium salt. Examples of aniline onium salt compounds include N,N-dimethylaniline salt, N,N-diethylaniline salt, and N,N-dialkylaniline salt.

[0075] (A2) The component can be an aniline onium salt having an anion containing boron as a constituent element. Commercially available examples of such salt compounds include, for instance, CXC-1821 (trade name, manufactured by King Industries).

[0076] From the viewpoint of ensuring the formation and curing properties of the first adhesive layer, the content of component (A2) relative to 100 parts by mass of component (A1) can be, for example, 0.001 to 1 part by mass, 0.005 to 0.7 parts by mass, 0.01 to 0.5 parts by mass, or 0.03 to 0.3 parts by mass.

[0077] From the viewpoint of maintaining reliability, the content of component (A), based on the total mass of the first adhesive layer, can be 5% by mass or more, 10% by mass or more, 15% by mass or more, or 20% by mass or more. From the viewpoint of preventing poor resin seepage in the roll, which is one form of supply, the content of component (A), based on the total mass of the first adhesive layer, can be 80% by mass or less, 70% by mass or less, 60% by mass or less, or 50% by mass or less. When the content of component (A) is within the above ranges, it tends to significantly exert the effects of the present invention.

[0078] [Other ingredients]

[0079] The first adhesive layer may further contain other components. Examples of other components include, for instance, thermoplastic resins (hereinafter, sometimes referred to as "component (B)"), coupling agents (hereinafter, sometimes referred to as "component (C)"), and fillers (hereinafter, sometimes referred to as "component (D)").

[0080] Component (B) may include, for example, phenoxy resins, polyester resins, polyamide resins, polyurethane resins, polyester urethane resins, acrylic rubbers, and epoxy resins (which are solid at 25°C). These may be used individually or in combination. Among these, component (B) may be, for example, a phenoxy resin. The content of component (B), based on the total mass of the first adhesive layer, may be 1% or more by mass, 3% or more by mass, or 5% or more by mass, or it may be 60% or less by mass, 40% or less by mass, or 20% or less by mass.

[0081] Examples of component (C) include silane coupling agents having organic functional groups such as (meth)acryloyl, mercapto, amino, imidazole, and epoxy groups; silane compounds such as tetraalkoxysilanes; tetraalkoxytitanate derivatives; and polydialkyltitanate derivatives. These can be used individually or in combination. The presence of component (C) in the first adhesive layer further enhances adhesion. Component (C) can be, for example, a silane coupling agent. The content of component (C), based on the total mass of the first adhesive layer, can be 0.1 to 10% by mass.

[0082] As component (D), examples include non-conductive fillers (e.g., non-conductive particles). Component (D) can be either inorganic or organic fillers. Examples of inorganic fillers include metal oxide particles such as silica particles, alumina particles, silica-alumina particles, titanium dioxide particles, and zirconium dioxide particles; and inorganic particles such as metal nitride particles. Examples of organic fillers include silicone particles, methacrylate-butadiene-styrene particles, acrylic-silicone particles, polyamide particles, and polyimide particles. These can be used individually or in combination. Component (D) can be, for example, silica particles. The content of component (D), based on the total mass of the first adhesive layer, can be 1% or more by mass, 10% or more by mass, or 30% or more by mass, or 90% or less by mass, 70% or less by mass, or 50% or less by mass.

[0083] [Other Additives]

[0084] The first adhesive layer may further contain other additives such as softeners, accelerators, degradation inhibitors, colorants, flame retardants, and thixotropic agents. The content of other additives is based on the total mass of the first adhesive layer, for example, it may be 0.1 to 10% by mass.

[0085] The thickness of the first adhesive layer can be appropriately set according to the height of the electrodes of the circuit components being bonded. From the viewpoint of fully filling the space between the electrodes to seal them and obtaining better connection reliability, the thickness of the first adhesive layer can be 5.0 μm or more, or 6.0 μm or more, or 30.0 μm or less, 20.0 μm or less, 15.0 μm or less, or 13.0 μm or less. Additionally, as... Figure 2 and Figure 3 As shown, when a portion of the conductive particles 1 contained in the second adhesive layer 22 protrudes from the surface of the second adhesive layer 22 (e.g., protruding toward the first adhesive layer 12), the distance from the surface of the first adhesive layer 12 opposite to the side of the second adhesive layer 22 to the boundary between the second adhesive layer 22 and the first adhesive layer 12 at the separated portion of the adjacent conductive particles 1 (in... Figure 2 and Figure 3 The distance represented by d2 is the thickness of the first adhesive layer 12.

[0086] The thickness of the first adhesive layer can be determined, for example, by the method described in the examples. Specifically, it can be determined by the following method: The adhesive film for circuit connection is held between two pieces of glass (thickness: approximately 1 mm). After molding 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 curing agent (trade name: Epomount curing agent, manufactured by Refine Tec Ltd.), the cross-section is ground using a grinding machine, and the thickness is determined using a scanning electron microscope (SEM, trade name: SE-8020, manufactured by Hitachi High-TechScience Corporation). This operation can be performed multiple times, and the average value is taken as the thickness of the first adhesive layer.

[0087] (Second adhesive layer)

[0088] The second adhesive layer contains conductive particles (hereinafter, sometimes referred to as "component (E)") and a thermosetting composition. In addition to component (E), the second adhesive layer may contain non-conductive components (e.g., insulating resin components). The thermosetting composition is a composition that is cured by heat in at least a portion and may contain component (A) as described above. The second adhesive layer may further contain a light-curing resin component (hereinafter, sometimes referred to as "component (F)"). When the second adhesive layer contains component (F), the second adhesive layer may contain a cured product of component (F). The cured product of component (F) may be a cured product formed by completely curing component (F) or a cured product formed by partially curing component (F). The second adhesive layer can be obtained, for example, by irradiating a composition layer consisting of a composition containing component (E), a thermosetting composition, and component (F) with light energy, causing the components contained in component (F) to polymerize, thereby producing a cured product of component (F). The thermosetting composition is a component that can flow during circuit connection.

[0089] [(E) Component: Conductive particles]

[0090] (E) Components are not particularly limited as long as they are conductive particles, and can be metal particles composed of metals such as Au, Ag, Pd, Ni, Cu, and solder, or conductive carbon particles composed of conductive carbon. (E) Components can be coated conductive particles having a core and a coating layer. The core may include non-conductive glass, ceramics, plastics (such as polystyrene), etc., and the coating layer may contain the aforementioned metals or conductive carbon and coat the core. (E) Components can use one type of conductive particle alone, or multiple conductive particles can be used in combination. (E) Components can be coated conductive particles having a core containing plastic and a coating layer containing metal or conductive carbon and coating the core, or metal particles formed from molten metal.

[0091] When component (E) is coated with conductive particles, the cured thermosetting resin component can be easily deformed by heating or pressurizing. Therefore, when the electrodes are electrically connected to each other, the contact area between the electrodes and component (E) can be increased, further improving the conductivity between the electrodes.

[0092] When component (E) is metal particles formed from molten metal, there is a tendency for the connection between electrodes to become stronger. This tendency is significant when solder particles are used as component (E).

[0093] From the viewpoint of balancing connection strength and low melting point, the solder particles may contain at least one element selected from the group consisting of tin, tin alloys, indium, and indium alloys. Furthermore, from the viewpoint of achieving higher reliability during high-temperature and high-humidity testing and thermal shock testing, the solder particles may contain at least one element selected from the group consisting of In-Bi alloys, In-Sn alloys, In-Sn-Ag alloys, Sn-Au alloys, Sn-Bi alloys, Sn-Bi-Ag alloys, Sn-Ag-Cu alloys, and Sn-Cu alloys.

[0094] Component (E) can be an insulating coated conductive particle having the aforementioned metal particles, the aforementioned conductive carbon particles, or the aforementioned coated conductive particles, and an insulating layer containing an insulating material such as resin covering the surface of the particle. When component (E) is an insulating coated conductive particle, even when the content of component (E) is high, since an insulating layer is present on the particle surface, short circuits caused by contact between components (E) can be suppressed, and the insulation between adjacent electrode circuits can also be improved.

[0095] The maximum particle size of component (E) needs to be smaller than the minimum spacing between electrodes (the shortest distance between adjacent electrodes). From the viewpoint of excellent dispersibility and conductivity, the maximum particle size of component (E) can 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 component (E) can 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 (pcs) of component (E) in the second adhesive layer, the particle size is determined by observation using a scanning electron microscope (SEM), and the largest value obtained is taken as the maximum particle size of component (E). In addition, in cases where component (E) is not spherical, such as having protrusions, the particle size of component (E) is set to the diameter of the circle tangent to the conductive particles in the SEM image.

[0096] From the viewpoint of excellent dispersibility and conductivity, the average particle size of component (E) can 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 component (E) can 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, the particle size of any 300 (pcs) of component (E) in the second adhesive layer is determined by observation using a scanning electron microscope (SEM), and the average value of the obtained particle size is taken as the average particle size.

[0097] In the second adhesive layer, component (E) can be uniformly dispersed. From the viewpoint of obtaining stable connection resistance, the particle density of component (E) in the adhesive film for circuit connection can be 100 particles / mm². 2 Above, 1000 pieces / mm 2 Above, 3000 pieces / mm 2 Above, 5000 pieces / mm 2 Above, 7000 pieces / mm 2 Above, 10,000 pieces / mm 2 More than or 12,000 pieces / mm 2 That's all. From the viewpoint of improving the insulation between adjacent electrodes, the particle density of the (E) component in the adhesive film for circuit connections can be 100,000 particles / mm². 2 Below, 70,000 pieces / mm 2 Below, 50,000 pieces / mm 2 Below, 30,000 pieces / mm 2 Below or 20,000 pieces / mm 2 the following.

[0098] From the viewpoint of further improving conductivity, the content of component (E), based on the total mass of the second adhesive layer, can be 1% or more, 5% or more, or 10% or more by mass. From the viewpoint of easily suppressing short circuits, the content of component (E), based on the total mass of the second adhesive layer, can be 60% or less, 50% or less, or 40% or less by mass. When the content of component (E) is within the above range, it tends to significantly exert the effects of the present invention. In addition, when the second adhesive layer contains component (F), the content of component (E) 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) can be the same as the above range.

[0099] [(A) Ingredient: Thermosetting resin component]

[0100] The components (A1) and (A2) used in component (A) of the second adhesive layer are the same as those used in component (A1) of the first adhesive layer. Component (A) of the second adhesive layer may be the same as or different from component (A) of the first adhesive layer.

[0101] From the viewpoint of ensuring the curability of the second adhesive layer, the content of component (A), based on the total mass of the second adhesive layer, can be 5% by mass or more, 10% by mass or more, 15% by mass or more, or 20% by mass or more. From the viewpoint of ensuring the formability of the second adhesive layer, the content of component (A), based on the total mass of the second adhesive layer, can be 70% by mass or less, 60% by mass or less, 50% by mass or less, or 40% by mass or less. When the content of component (A) is within the above range, it tends to significantly exert the effects of the present invention. In addition, when the second adhesive layer contains component (F), the content of component (A) 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) can be the same as the above range.

[0102] [(F) Component: Light-curable resin component]

[0103] Component (F) is not particularly limited as long as it is a resin component that is cured by light irradiation. However, if component (A) is a resin component with cationic curing properties, from the viewpoint of superior connection resistance, component (F) can be a resin component with free radical curing properties. Component (F) may, for example, include a free radical polymerizable compound (hereinafter sometimes referred to as "component (F1)") and a photoradical polymerization initiator (hereinafter sometimes referred to as "component (F2)"). Component (F) can be a composition consisting of components (F1) and (F2).

[0104] (F1) Composition: Free radical polymeric compound

[0105] Component (F1) is a compound polymerized by free radicals generated from component (F2) through irradiation with light (e.g., ultraviolet light). Component (F1) can be any of a monomer or a polymer (or oligomer) formed by polymerizing one or more monomers. Component (F1) can be used alone or in combination.

[0106] Component (F1) is a compound having a free radical polymerizable group that reacts via a free radical. Examples of free radical polymerizable groups include (meth)acryloyl, vinyl, allyl, styrene, alkenyl, alkenylene group, and maleimide group. From the viewpoint of easily obtaining the desired melt viscosity and achieving better bonding reliability after polymerization, the number of free radical polymerizable groups (functional groups) in component (F1) can be 2 or more. From the viewpoint of further improving the reduction effect on bonding resistance and suppressing curing shrinkage during polymerization, the number of free radical polymerizable groups (functional groups) in component (F1) can be 10 or less, 6 or less, or 4 or less. Furthermore, in order to achieve a balance between crosslinking density and curing shrinkage, in addition to compounds with the number of free radical polymerizable groups within the above range, compounds with the number of free radical polymerizable groups outside the above range can also be used.

[0107] From the viewpoint of suppressing the flow of conductive particles, the (F1) component can contain polyfunctional (2 or more functional) (meth)acrylates. The polyfunctional (2 or more functional) (meth)acrylates can be difunctional or trifunctional (meth)acrylates, or they can be difunctional (meth)acrylates. The difunctional (meth)acrylates can be difunctional aromatic (meth)acrylates.

[0108] Examples of multifunctional (meth)acrylates include ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, tetrapropylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, ethoxylated polypropylene glycol di(meth)acrylate, 1,3-butanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 3 Aliphatic (meth)acrylates include methyl-1,5-pentanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 2-butyl-2-ethyl-1,3-propanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, glycerol di(meth)acrylate, tricyclodecanediethanol (meth)acrylate, and ethoxylated 2-methyl-1,3-propanediol di(meth)acrylate; ethoxylated bisphenol A type di(meth)acrylate, propoxylated bisphenol A type di(meth)acrylate, ethoxylated propoxylated bisphenol A type di(meth)acrylate, and ethyl... Oxylated bisphenol F di(meth)acrylate, propoxylated bisphenol F di(meth)acrylate, ethoxylated propoxylated bisphenol F di(meth)acrylate, ethoxylated fluorene di(meth)acrylate, propoxylated fluorene di(meth)acrylate, ethoxylated propoxylated fluorene di(meth)acrylate, etc., aromatic (meth)acrylates, 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, etc. Aliphatic (meth) acrylates, such as methacrylates, propoxylated pentaerythritol tri(meth)acrylates, ethoxylated propoxylated pentaerythritol tri(meth)acrylates, pentaerythritol tetra(meth)acrylates, ethoxylated pentaerythritol tetra(meth)acrylates, propoxylated pentaerythritol tetra(meth)acrylates, ethoxylated propoxylated pentaerythritol tetra(meth)acrylates, di(trimethylolpropane)tetraacrylate, dipentaerythritol hexa(meth)acrylates; and aromatic epoxy (meth) acrylates, such as bisphenol type epoxy (meth)acrylates, phenolic varnish type epoxy (meth)acrylates, and cresol phenolic varnish type epoxy (meth)acrylates.

[0109] From the perspective of balancing the reduction of connection resistance and the suppression of particle flow, the content of multifunctional (2 or more functional) (meth)acrylate is based on the total mass of (F1) component, for example, it can be 50-100% by mass, 70-100% by mass, or 90-100% by mass, or 100% by mass.

[0110] In addition to containing polyfunctional (2 or more functional) meth)acrylates, (F1) ingredients may further contain monofunctional (meth)acrylates. Examples of monofunctional (meth)acrylates include: methacrylic acid; methyl methacrylate, ethyl methacrylate, butyl methacrylate, isobutyl methacrylate, tert-butyl methacrylate, butoxyethyl methacrylate, isoamyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, heptyl methacrylate, octylheptyl methacrylate, nonyl methacrylate, decyl methacrylate, and 2-ethylhexyl methacrylate. Hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 3-chloro-2-hydroxypropyl acrylate, 2-hydroxybutyl acrylate, methoxy polyethylene glycol (meth)acrylate, ethoxy polyethylene glycol (meth)acrylate, methoxy polypropylene glycol (meth)acrylate, ethoxy polypropylene glycol (meth)acrylate, mono(2-(meth)acryloyloxyethyl)succinate, and other aliphatic (meth)acrylates; benzyl acrylate, phenyl acrylate, o-phenyl acrylate, and (methyl) 1-Naphthyl acrylate, 2-naphthyl (meth)acrylate, phenoxyethyl (meth)acrylate, p-isopropylphenoxyethyl (meth)acrylate, o-phenylphenoxyethyl (meth)acrylate, 1-naphthyl (meth)acrylate, 2-naphthyl (meth)acrylate, phenoxy polyethylene glycol (meth)acrylate, nonylphenoxy polyethylene glycol (meth)acrylate, phenoxy polypropylene glycol (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, 2-hydroxy-3-meth)acrylate Aromatic (meth)acrylates such as propyl (o-phenylphenoxy)acrylate, 2-hydroxy-3-(1-naphthoxy)propyl (meth)acrylate, and 2-hydroxy-3-(2-naphthoxy)propyl (meth)acrylate; epoxy-containing (meth)acrylates such as glycidyl (meth)acrylate; alicyclic epoxy-containing (meth)acrylates such as 3,4-epoxycyclohexyl methyl (meth)acrylate; and oxetyl (meth)acrylates such as (3-ethyloxetane-3-yl)methyl (meth)acrylate.

[0111] The content of monofunctional (meth)acrylate is based on the total mass of (F1) component, for example, it can be 0-50% by mass, 0-30% by mass, or 0-10% by mass, or it can be 0% by mass.

[0112] The cured product of component (F) may, for example, have polymerizable groups that react via groups other than free radicals. Regarding polymerizable groups that react via groups other than free radicals, for example, it may be a cationic polymerizable group that reacts via a cation. Examples of cationic polymerizable groups include epoxy groups such as glycidyl, alicyclic epoxy groups such as cyclohexylmethyl, and oxetyl groups such as ethyloxetylmethyl. Regarding the cured product of component (F) having polymerizable groups that react via groups other than free radicals, for example, it is possible to introduce (meth)acrylates having epoxy groups, alicyclic epoxy groups, oxetyl groups, etc., which have polymerizable groups that react via groups other than free radicals, as component (F). From the perspective of improving reliability, the mass ratio of (meth)acrylate with polymerizable groups that react through groups other than free radicals to the total mass of (F1) component (mass of (meth)acrylate with polymerizable groups that react through groups other than free radicals (amount added) / total mass of (F1) component (amount added)) can be, for example, 0 to 0.7, 0 to 0.5 or 0 to 0.3.

[0113] In addition to polyfunctional (2 or more functional) and monofunctional (meth)acrylates, component (F1) may also contain other free radical polymerizable compounds. Examples of other free radical polymerizable compounds include maleimide compounds, vinyl ether compounds, allyl compounds, styrene derivatives, acrylamide derivatives, and nadimide derivatives. The content of other free radical polymerizable compounds is based on the total mass of component (F1), and may range from 0 to 40% by mass.

[0114] (F2) Component: Photoradical polymerization initiator

[0115] (F2) is a photopolymerization initiator that generates free radicals by irradiation with light containing wavelengths in the range of 150–750 nm, light containing wavelengths in the range of 254–405 nm, or light containing wavelengths in the range of 365 nm (e.g., ultraviolet light). (F2) can be used alone or in combination.

[0116] (F2) component generates free radicals through photodecomposition. That is, (F2) component is a compound that generates free radicals by receiving light energy from the outside. (F2) component can be a compound having structures such as oxime ester, diimidazole, acridine, α-aminoalkylphenyl ketone, aminobenzophenone, N-phenylglycine, acylphosphine oxide, benzyl dimethyl ketal, or α-hydroxyalkylphenyl ketone. (F2) component can be used alone or in combination. From the viewpoint of easily obtaining the desired melt viscosity and achieving a better reduction in connection resistance, (F2) component can be a compound having at least one structure selected from the group consisting of oxime ester, α-aminoalkylphenyl ketone, and acylphosphine oxide.

[0117] Specific examples of compounds having an oxime ester structure include 1-phenyl-1,2-butanedione-2-(o-methoxycarbonyl)oxime, 1-phenyl-1,2-propanedione-2-(o-methoxycarbonyl)oxime, 1-phenyl-1,2-propanedione-2-(o-ethoxycarbonyl)oxime, 1-phenyl-1,2-propanedione-2-o-benzoyl oxime, 1,3-diphenyltrione-2-(o-ethoxycarbonyl)oxime, 1-phenyl-3-ethoxytrione-2-(o-benzoyl)oxime, 1,2-octanedione, 1-[4-(phenylthio)phenyl-,2-(o-benzoyl oxime)], ethyl ketone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]-, 1-(o-acetyl oxime), etc.

[0118] Specific examples of compounds having the α-aminoalkylphenyl ketone structure include 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinylpropane-1-one, 2-benzyl-2-dimethylamino-1-morpholinylphenyl)-butanone-1, etc.

[0119] Specific examples of compounds having an acylphosphine oxide structure include bis(2,6-dimethoxybenzoyl)-2,4,4-trimethyl-pentylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, and 2,4,6-trimethylbenzoyl-diphenylphosphine oxide.

[0120] From the viewpoint of suppressing the flow of conductive particles, the content of component (F2) relative to component (F1) is, for example, 0.1 to 10 parts by mass, 0.3 to 7 parts by mass, or 0.5 to 5 parts by mass.

[0121] From the viewpoint of suppressing the flow of conductive particles, the content of the cured (F) component, based on the total mass of the second adhesive layer, can be 1% or more by mass, 5% or more by mass, or 10% or more by mass. From the viewpoint of exhibiting low resistance in low-voltage packaging, the content of the cured (F) component, based on the total mass of the second adhesive layer, can be 50% or less by mass, 40% or less by mass, or 30% or less by mass. When the content of the cured (F) component is within the above range, it tends to significantly exert the effects of the present invention. Furthermore, the content of the (F) component in the composition or composition layer (based on the total mass of the composition or composition layer) can be the same as the above range.

[0122] [Other ingredients]

[0123] The second adhesive layer may further contain other components. Examples of other components include, for example, component (B), component (C), etc. Furthermore, components (B) and (C) in the second adhesive layer and their manner are the same as those in the first adhesive layer.

[0124] The content of component (B) can be 1% or more, 5% or more, or 10% or more by mass, based on the total mass of the second adhesive layer, and can be 70% or less, 50% or less, or 30% or less by mass. Furthermore, if 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) can be the same as described above.

[0125] The content of component (C) can be 0.1% to 10% by mass, based on the total mass of the second adhesive layer. In addition, if the second adhesive layer contains component (F), the content of component (C) in the composition or composition layer containing component (E), thermosetting composition and component (F) (based on the total mass of the composition or composition layer) can be the same as the above range.

[0126] [Other Additives]

[0127] The second adhesive layer may further contain other additives found in the first adhesive layer. These other additives are in the same form as those in the first adhesive layer.

[0128] The thickness of the second adhesive layer can be, for example, 30.0 μm or less, or 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 using a second adhesive layer thickness of 30.0 μm or less, the resin content between the opposing circuits is reduced, which can suppress the increase in connection resistance between the opposing circuits. This tendency is more pronounced when the thickness of the second adhesive layer is 5.0 μm or less. The thickness of the second adhesive layer can, for example, be 0.1 μm or more, or 0.7 μm or more. Furthermore, as... Figure 2 and Figure 3 As shown, when a portion of the conductive particle 1 protrudes from the surface of the second adhesive layer 22 (e.g., protruding towards the first adhesive layer 12), the distance from the surface of the second adhesive layer 22 opposite to the side of the first adhesive layer 12 to the boundary between the second adhesive layer 22 and the first adhesive layer 12 at the separated portion of the adjacent conductive particles 1, 1 (in Figure 2 and Figure 3 The distance represented by d1 is the thickness of the second adhesive layer 22, and the exposed portion of the conductive particle 1 is not included in the thickness of the second adhesive layer 22. The length of the exposed portion of the conductive particle 1 can be, for example, more than 0.1 μm or less than 5.0 μm.

[0129] The thickness of the second adhesive layer can be determined, for example, in the same way as the method used to determine the thickness of the first adhesive layer.

[0130] From the viewpoint that conductive particles can be easily captured between opposing electrodes and the connection resistance can be further reduced, the ratio of the thickness of the second adhesive layer to the average particle size of the conductive particles (thickness of the second adhesive layer / average particle size of the conductive particles) can be 0.1 or more, 0.3 or more, or 0.5 or more. For example, the ratio can be 2.0 or less, 1.5 or less, 1.2 or less, or 1.0 or less.

[0131] According to the winding body of the adhesive film for circuit connection according to this embodiment, the adhesion between the adhesive film for circuit connection rolled out of the winding body and circuit electrodes during heat pressing can be improved. Furthermore, the heating temperature during heat pressing between the adhesive film for circuit connection rolled out of the winding body and circuit electrodes can be reduced.

[0132] <Method for manufacturing a wound body of adhesive film for circuit connection>

[0133] The method for manufacturing a wound body of an adhesive film for circuit connection according to this embodiment is a method for manufacturing a wound body of an adhesive film for circuit connection having a substrate and a first adhesive layer containing a thermosetting composition disposed on the substrate and a second adhesive layer containing conductive particles and a thermosetting composition. The method includes: step S1, preparing a roll of raw material formed by winding a laminate, the laminate sequentially having a first substrate, a first adhesive layer containing a thermosetting composition, a second adhesive layer containing conductive particles and a thermosetting composition, and a second substrate; and step S2, after processing the laminate rolled from the roll of raw material including a step of cutting to a predetermined width and a step of peeling off one of the first substrate and the second substrate, winding it onto a core, thereby obtaining the wound body of the adhesive film for circuit connection. Furthermore, in step S2, only one winding of the laminate after peeling off one of the first substrate and the second substrate is performed.

[0134] In the method for manufacturing the winding body of the adhesive film for circuit connection, the first substrate, the second substrate, the first adhesive layer, and the second adhesive layer can be the same materials as those in the winding body of the adhesive film for circuit connection of this embodiment described above.

[0135] <Process S1>

[0136] In step S1, a roll of raw material is prepared by winding a laminate (sometimes referred to as laminate A) having a first substrate, a first adhesive layer, a second adhesive layer, and a second substrate sequentially onto a core. The roll of raw material can be formed by winding laminate A onto the core with the first substrate facing outwards, or by winding laminate A onto the core with the second substrate facing outwards. The width of the roll of raw material is not particularly limited and can be 25–60 cm.

[0137] Step S1 may include: a step of preparing a laminate having a first adhesive layer formed on a first substrate (first preparation step); a step of preparing a laminate having a second adhesive layer formed on a second substrate (second preparation step); a step of preparing a laminate A by bonding the laminate having the first adhesive layer formed on the first substrate and the laminate having the second adhesive layer formed on the second substrate in a manner where the first adhesive layer and the second adhesive layer are facing each other (lamination step); and a step of preparing a roll of raw material formed by winding the laminate A onto a core (winding step). In step S1, a pre-made roll of raw material may also be prepared. Figure 4 This is a perspective view illustrating an example of the lamination and winding processes. Figure 5 It is used for explanation Figure 4 An enlarged schematic cross-sectional view of the process shown.

[0138] [First Preparation Step]

[0139] In the first preparation step, for example, a first adhesive layer is formed on a first substrate. Specifically, for example, components (A), (B), (C), and (D), as well as other components to be added as needed, are added to a solvent (organic solvent), and dissolved or dispersed by stirring, mixing, kneading, etc., thereby preparing a composition for the first adhesive layer. Then, the adjusted composition for the first adhesive layer is applied to the first substrate using a doctor blade coater, roller coater, applicator, comma coater, die coater, etc., and the solvent is evaporated by heating, thus forming the first adhesive layer on the first substrate. As a result, a laminate with a first adhesive layer formed on the first substrate can be prepared.

[0140] As a solvent for preparing the composition for the first adhesive layer, a solvent with the property of uniformly dissolving or dispersing the components can be used. Examples of such solvents include toluene, acetone, methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate, propyl acetate, and butyl acetate. These solvents can be used alone or in combination of two or more. The mixing and kneading of the varnish composition can be performed using a mixer, grinder, three-roll mill, ball mill, bead mill, or homogenizing disperser.

[0141] The heating conditions under which the solvent evaporates from the first adhesive layer coated on the first substrate can be conditions that allow the solvent to evaporate sufficiently. For example, the heating conditions can be set to 40°C or higher and 120°C or lower, and for 0.1 minutes or higher and 10 minutes or lower.

[0142] In the first adhesive layer, a portion of the solvent may remain without being removed. The solvent content in this layer is based on the total mass of the first adhesive layer, and may be, for example, less than 10% by mass.

[0143] [Second Preparation Step]

[0144] In the second preparation step, for example, a second adhesive layer is formed on the second substrate. Specifically, for example, components (E), (F), (A), (B), and (C), and other components added as needed are used. Otherwise, similar to the first preparation step, the second adhesive layer is formed on the second substrate, thereby enabling the preparation of a laminate with the second adhesive layer formed on the second substrate.

[0145] A portion of the solvent may remain in the second adhesive layer. The solvent content in the second adhesive layer is based on the total mass of the second adhesive layer, and may be, for example, less than 10% by mass.

[0146] [Lamination process]

[0147] In the stacking process, for example, as Figure 4 and Figure 5As shown, the laminate 10 and the laminate 20 can be laminated with the surface of the first adhesive layer 12 (opposite to the first substrate 11) in the laminate 10 having a first substrate 11 and a first adhesive layer 12 disposed thereon facing each other, and the surface of the second adhesive layer 22 (opposite to the second substrate 21) in the laminate 20 having a second substrate 21 and a second adhesive layer 22 disposed thereon facing each other. The lamination temperature can be, for example, 0 to 80°C. The lamination pressure (crimping pressure) can be, for example, 0.5 to 1.5 MPa. The lamination time (crimping time) can be, for example, 0.5 to 1.5 seconds.

[0148] [Winding process]

[0149] In the winding process, laminate A can be wound onto the core with the first substrate facing outwards using known methods, or it can be wound onto the core with the second substrate facing outwards. In the winding process, the winding tension of laminate A can, for example, be 10–50 N / m. Figure 4 and Figure 5 In the process, the laminate A52 is wound onto the core with the first substrate 11 as the outer side, thereby obtaining a roll of raw material 40.

[0150] <Process S2>

[0151] In step S2, the laminated body rolled from the aforementioned roll of raw material undergoes a process including cutting it to a predetermined width and peeling off one of the first substrate and the second substrate, and is then wound into a core to obtain the aforementioned roll of adhesive film for circuit connection. The process of cutting to a predetermined width may include a process of subdividing the roll of raw material to obtain a roll A with a smaller width (blocking process) and a slitting process of cutting to the width of the adhesive film for circuit connection.

[0152] Other than the above-mentioned processes include inspection procedures such as foreign object inspection and visual inspection, and light irradiation procedures. These processes can be performed before one of the first substrate and the second substrate is peeled off.

[0153] [Blocking Process]

[0154] For example, such as Figure 6 As shown, the block forming process can roll out a laminate A52 from the roll of raw material 40 in a roll-to-roll manner, cut the laminate A52 to a specified width using a slitting blade 92 to form a laminate A54, and then wind the laminate A54 into a core to form a winding body A42. The roll-out tension and take-up tension of the laminate A can be, for example, 5 to 30 N / m. The block forming process can be performed multiple times. Cutting can be performed using known methods other than the slitting blade.

[0155] In the block forming process, for example, the laminate A52 can be cut into widths of 10-30 mm or 10-25 mm while having a first substrate 11 and a second substrate 21, and then wound into a core to form a winding body A42.

[0156] [Inspection Procedure]

[0157] As an inspection process, it may include, for example, the steps of winding the laminate from the rolled raw material or the wound body A and inspecting the laminate for foreign objects, and then winding the laminate into a core. Examples of methods for inspecting foreign objects include visually observing the foreign objects and inspecting the foreign objects using a visual inspection machine.

[0158] [Light irradiation process]

[0159] When the second adhesive layer contains component (F), a laminate having a second adhesive layer that has been light-irradiated on a second substrate can be prepared in step S1 prior to step S1. The second adhesive layer can be light-irradiated in step S1, or step S2 can include a light-irradiation step. In the light-irradiation step, a cured product of component (F) is obtained from the component (F) contained in the second adhesive layer by irradiating the second adhesive layer with light.

[0160] Irradiation can be performed using light with wavelengths ranging from 150 to 750 nm (e.g., ultraviolet light). Irradiation can be achieved using, for example, low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, xenon lamps, metal halide lamps, LED light sources, etc. The cumulative light intensity can be appropriately set, for example, from 500 to 3000 mJ / cm². 2 .

[0161] Light irradiation can be performed on a laminate in step S1 on which a second adhesive layer is formed on a second substrate, on a laminate rolled out from a roll of raw material in step S2, or on the adhesive film for circuit connection involved in this embodiment in step S2. Regarding light irradiation, the second adhesive layer can be irradiated directly; when the second substrate transmits light, irradiation can be performed by light passing through the second substrate side; when the first adhesive layer transmits light, irradiation can be performed by light passing through the first adhesive layer side; and when both the first substrate and the first adhesive layer transmit light, irradiation can be performed by light passing through both the first substrate side.

[0162] In process S2, the process of peeling off one of the first substrate and the second substrate (peeling process) can be performed at the same time as or before the slitting process. Figure 7 This is a three-dimensional diagram representing an example of process S2. Figure 8 It is used for explanation Figure 7 An enlarged schematic cross-sectional view of the process shown. Figure 7 and Figure 8 In step S2 shown, the second substrate 21 is peeled off from the laminate 54 rolled out from the roll A42 obtained in the block forming process, and the circuit connection adhesive film 55, from which the second substrate 21 has been peeled off, is slit to a specified width by a rotating blade 94, thereby obtaining the roll 100 of the circuit connection adhesive film 56. The slitting process can be performed using known methods other than the rotating blade.

[0163] The roll-out tension and roll-up tension when peeling off one of the first and second substrates can be, for example, 5 to 30 N / m. The slitting process can be performed using known methods.

[0164] In the slitting process, the laminate can be cut in such a way that the width of the adhesive film for circuit connection is 0.5-3 mm, 0.8-2.0 mm or 1.0-1.5 mm.

[0165] exist Figure 7 and Figure 8 In this process, after peeling the second substrate 21 from the laminate A54, the adhesive film 55 for circuit connection is slit to obtain the adhesive film 56 for circuit connection. Alternatively, the adhesive film 56 for circuit connection can be obtained by peeling the second substrate 21 after slitting the laminate A54.

[0166] exist Figure 7 and Figure 8 In this process, the adhesive film 56 for circuit connection is wound onto the core 110 with the first substrate 11 as the outer side, but it can also be wound onto the core with the first substrate 11 as the inner side. Furthermore, in... Figure 7 and Figure 8 In this process, the second substrate 21 is peeled off from the laminate A54, but the first substrate 11 can also be peeled off instead of the second substrate 21 to serve as an adhesive film for circuit connection. In this case, the adhesive film for circuit connection can be wound onto the core with the second substrate 21 on the outside or with the second substrate 21 on the inside.

[0167] If the laminate is cut to the width of the adhesive film for circuit connection before one of the first substrate and the second substrate is peeled off, one of the first substrate and the second substrate can be peeled off from the laminate and wound into a core.

[0168] According to the manufacturing method of the wound body of the adhesive film for circuit connection according to this embodiment, in step S2, only one of the first substrate and the second substrate is peeled off in a single winding. Therefore, from the preparation of the roll-shaped raw material in step S1 until the wound body of the adhesive film for circuit connection is obtained, the adhesive layer on the side opposite to the substrate side can be prevented from becoming too coarse. This prevents a decrease in the capture ability of conductive particles and allows for the acquisition of a wound body of the adhesive film for circuit connection with the desired conductive particle capture ability. When peeling off the second substrate in step S2, a decrease in the capture ability of conductive particles can be prevented more effectively. Furthermore, when peeling off the first substrate in step S2, if the thickness of the adhesive layer is 3 μm or less, a decrease in the capture ability of conductive particles can be prevented more effectively.

[0169] Example

[0170] The present invention will be described in more detail below through embodiments, but the present invention is not limited to the embodiments.

[0171] <The Production of Conductive Particles>

[0172] Ni plating was applied to the surface of the plastic core, and Pd was applied to the outermost surface for displacement plating, thereby obtaining conductive particles (average particle size: 3.2 μm).

[0173] <Preparation of thermosetting compositions for the first and second adhesive layers>

[0174] The following components were prepared by mixing the proportions (parts by mass) shown in Table 1 to prepare a composition for a first adhesive layer and a composition for a second adhesive layer (1) and (2).

[0175] (A) Composition: Thermosetting resin component

[0176] (A1) Composition: Cationic polymeric compound

[0177] A1-1: ETERNACOLL OXBP (oxetane compound, manufactured by UBE Corporation)

[0178] A1-2: EHPE3150 (Alicyclic epoxy compound, manufactured by Daicel Corporation)

[0179] A1-3: CEL2021P (Alicyclic epoxy compound, manufactured by Daicel Corporation)

[0180] A1-4: JER1007 (Epoxy compound, manufactured by Mitsubishi Chemical Corporation)

[0181] (A2) Composition: At the start of thermal cationic polymerization

[0182] A2: CXC-1821 (N-(p-methoxybenzyl)-N,N-dimethylaniline tetra(pentafluorophenyl)borate, manufactured by King Industries, Inc.)

[0183] (B) Composition: Thermoplastic resin

[0184] B1: FX-293 (Phenoxy resin, manufactured by NIPPON STEEL Chemical & Material Co., Ltd.)

[0185] B2: YP-70 (Phenoxy resin, manufactured by NIPPON STEEL Chemical & Material Co., Ltd.)

[0186] (C) Component: Coupling agent

[0187] C1: SH-6040 (3-Epoxypropoxypropyltrimethoxysilane, manufactured by Dow Corning Toray Co., Ltd.)

[0188] (D) Ingredients: Filler

[0189] D1: Admafine SE2050 (Silica microparticles, manufactured by Admatechs Co., Ltd.)

[0190] D2: AEROSIL R805 (Silica microparticles, manufactured by Evonik Industries AG)

[0191] (E) Composition: Conductive particles

[0192] E1: Conductive particles prepared as described above

[0193] (F) Composition: Light-curable resin components

[0194] (F1) Composition: Free radical polymeric compound

[0195] F1-1: VR-90 (Bisphenol A type epoxy (meth)acrylate (difunctional) (vinyl ester resin), manufactured by SHOWA DENKOK.K.)

[0196] F1-2: A-1000 (Polyethylene glycol diacrylate (difunctional), manufactured by Shin-Nakamura Chemical Co., Ltd.)

[0197] (F2) Component: Photoradical polymerization initiator

[0198] F2: Irgacure907 (a compound with an α-aminoalkylphenyl ketone structure, manufactured by BASF)

[0199] [Table 1]

[0200]

[0201] <Preparation of Substrate>

[0202] Substrate A (thickness: 50 μm, material: white PET) and substrate B (thickness: 50 μm, material: PET) were prepared with arithmetic mean height (Sa) and root mean square height (Sq) of the adhesive layer side and back side as shown in Table 2.

[0203] [Table 2]

[0204]

[0205] [Preparation of Rolled Raw Material A1]

[0206] <Fabrication of the laminate (1) (first substrate and first adhesive layer disposed thereon)>

[0207] The first adhesive layer composition described above was applied to the adhesive layer side surface of substrate A using a coating apparatus. Then, it was dried with hot air at 60°C for 3 minutes to form a first adhesive layer (a layer composed of the first adhesive layer composition) with a thickness of 6 μm. The thickness was measured using the adhesive layer thickness measurement method described later. Through the above operations, a laminate (1) having a first adhesive layer on a first substrate was obtained.

[0208] <Fabrication of the laminate (2) (second substrate and second adhesive layer disposed thereon)>

[0209] The second adhesive layer composition (1) was applied to the adhesive layer side surface of substrate B using a coating apparatus. Then, it was dried with hot air at 60°C for 3 minutes, forming a layer of the second adhesive layer composition (1) with a thickness (after drying) of 3 μm on the second substrate. The thickness was measured using the adhesive layer thickness measurement method described later. Next, the layer of the second adhesive layer composition (1) was UV irradiated using a metal halide lamp to achieve a cumulative light intensity of 1000 mJ / cm². 2The (F1) component is polymerized. This causes the second adhesive layer to cure with composition (1), forming the second adhesive layer. Through the above operations, a laminate (2) having a second adhesive layer on a second substrate is obtained. The conductive particle density at this time is approximately 18,000 particles / mm². 2 .

[0210] Laminate (1) and laminate (2) were arranged with their respective adhesive layers facing each other, and were laminated together with their respective substrates at 40°C using a roller laminator. This produced laminate A having a first substrate, a first adhesive layer, a second adhesive layer, and a second substrate in sequence. The obtained laminate A1 was wound onto a core with the first substrate facing outwards, resulting in a roll of raw material A1 with a width of 300 mm.

[0211] [Preparation of Rolled Raw Material A2]

[0212] The second adhesive layer composition (2) is used instead of the second adhesive layer composition (1), and 1000 mJ / cm is used instead. 2 With 2000 mJ / cm 2 UV irradiation was performed, and roll material A2 was produced using the same method as that used to produce roll material A1.

[0213] [Fabrication of the wound body for adhesive film for circuit connection]

[0214] (Example 1)

[0215] A laminate A1 is rolled out from a roll of raw material A1, cut to a width of approximately 20 mm using a roll-to-roll slitting device, and wound onto a core with the first substrate facing outwards, thus obtaining a wound body A. The obtained wound body A is then rolled out, the second substrate is peeled off, and cut to a width of approximately 2 mm using a roll-to-roll slitting device. After cutting, it is wound onto a core with the first substrate facing outwards, thus obtaining a wound body of adhesive film for circuit connection.

[0216] (Example 2)

[0217] The rolled material A2 was used instead of the rolled material A1. Otherwise, the wound body of the adhesive film for circuit connection was obtained in the same way as in Example 1.

[0218] (Comparative Example 1)

[0219] A laminate A1 is rolled out from a roll of raw material A1. After peeling off the second substrate, it is wound onto a core with the first substrate facing outwards, thus obtaining a wound body. Next, this wound body is rolled out and cut to a width of approximately 20 mm using a roll-to-roll slitting device, and then wound onto a core with the first substrate facing outwards, thus obtaining a wound body. The obtained wound body is rolled out and cut to a width of approximately 2 mm using a roll-to-roll slitting device. After cutting, it is wound onto a core with the first substrate facing outwards, thus obtaining a wound body of adhesive film for circuit connection.

[0220] (Comparative Example 2)

[0221] The rolled material A2 was used instead of the rolled material A1. Otherwise, the wound body of the adhesive film for circuit connection was obtained in the same way as in Comparative Example 1.

[0222] The following evaluation was conducted on the adhesive films for circuit connections rolled out from the winding bodies obtained in Examples 1 and 2, and Comparative Examples 1 and 2.

[0223] [Determination of adhesive layer thickness]

[0224] The adhesive film for circuit connection was held between two glass plates (thickness: about 1 mm). 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 curing agent (trade name: Epomount curing agent, manufactured by Refine Tec Ltd.), the cross section was ground using a grinder. The thickness of the first adhesive layer and the second adhesive layer (1) and (2) were measured using a scanning electron microscope (SEM, trade name: SE-8020, manufactured by Hitachi High-Tech Science Corporation).

[0225] [Evaluation of particle trapping capability]

[0226] An IC chip with bump electrodes (2mm × 20mm in size, 0.3mm in thickness, and 840μm area of ​​bump electrodes) was prepared. 2(70μm x 12μm), 12μm space between bump electrodes, 8μm height of bump electrodes), and a glass substrate (0.3mm thick) with a SiN / Al film. After aligning the bump electrodes of the IC chip with the circuit electrodes of the glass substrate, the first substrate was peeled off from the adhesive film for circuit connection. The IC chip and circuit electrodes were then clamped together with the second adhesive layer in contact with the circuit substrate. Heating and pressurizing were performed for 5 seconds at a measured maximum temperature of 210°C and an area-converted pressure of 27MPa on the bump electrodes to obtain the circuit connection structure. The number of indentations observed under a microscope was measured for 60 bumps of the electrodes in the circuit connection structure. Based on the mean (Ave) and standard deviation (σ) of the measured number of indentations, the capture count (number / 840μm) was calculated using the following formula. 2 ).

[0227] Capture count = Ave - 3σ… (formula)

[0228] [Evaluation of connectivity characteristics]

[0229] Regarding the circuit connection structures obtained in the same manner as the aforementioned particle capture number evaluation, both immediately after fabrication and after reliability testing, the resistance values ​​between opposing electrodes (between the bump electrode and the circuit electrode) of each circuit connection structure were measured using the four-terminal measurement method of a multimeter MLR21 (manufactured by Kusumoto Chemicals, Ltd.). The average value of the measured values ​​at 14 locations was compared to evaluate the connection resistance. The resistance value obtained immediately after fabrication was set as the initial resistance value, and the resistance value after the reliability test was set as the post-reliability resistance value. Furthermore, the reliability test was conducted by storing the circuit connection structures at a temperature of 110°C and a humidity of 85%RH for 64 hours.

[0230] [Evaluation of the surface shape of the second adhesive layer of the adhesive film for circuit connection]

[0231] Using an OLS4100 laser microscope (manufactured by Olympus Corporation), images were taken of the second adhesive layer side of the adhesive film used for circuit connections. The surface roughness parameters of the second adhesive layer were calculated using the included surface analysis software. The arithmetic mean height (Sa), root mean square height (Sq), skewness (Ssk), and kurtosis (Sku) were calculated as surface roughness parameters. Furthermore, images were taken at 100x magnification using an objective lens. In the included surface analysis software, the cutoff wavelength for analysis was set to 25 μm for λs; λc and λf were not set.

[0232] [Table 3]

[0233]

[0234] As shown in Table 3, comparing the adhesive films for circuit connections rolled from the winding bodies obtained in Examples 1 and 2 and Comparative Examples 1 and 2, the adhesive films for circuit connections rolled from the winding bodies obtained in Examples 1 and 2 exhibit superior particle trapping properties due to the large trapping number in Examples 1 and 2. Furthermore, the adhesive films for circuit connections rolled from the winding bodies obtained in Examples 1 and 2 exhibit superior connection characteristics due to the small initial resistance and post-reliability resistance values ​​in Examples 1 and 2. Moreover, it was confirmed that the adhesive films for circuit connections in Examples 1 and 2, whose surface Sq of the second adhesive layer is in the range of 0.005 to 0.1 μm, exhibit superior particle trapping properties compared to the adhesive films for circuit connections in Comparative Examples 1 and 2, whose surface Sq of the second adhesive layer exceeds 0.1 μm.

[0235] Symbol Explanation

[0236] 1-Conductive particle, 2-Adhesive component, 10-Laminated body having a first substrate and a first adhesive layer disposed thereon, 11-First substrate, 12-First adhesive layer, 20-Laminated body having a second substrate and a second adhesive layer disposed thereon, 21-Second substrate, 22-Second adhesive layer, 40-Rolled raw material, 42-Wound body A, 52, 54-Laminated body A, 55, 56, 58, 60-Adhesive film for circuit connection, 92-Slitting blade, 94-Rotating blade, 100-Wound body of adhesive film for circuit connection, 101-Substrate, 102, 102a, 102b-Adhesive layers, 110-Core.

Claims

1. A method for manufacturing a wound body of an adhesive film for circuit connection, comprising: a method for manufacturing a wound body of an adhesive film for circuit connection having a substrate and a first adhesive layer disposed on the substrate and comprising a thermosetting composition, and a second adhesive layer comprising conductive particles and a thermosetting composition, the method comprising: Step S1: Prepare a roll of raw material formed by winding a laminate, wherein the laminate sequentially comprises a first substrate, a first adhesive layer containing a thermosetting composition, a second adhesive layer containing conductive particles and a thermosetting composition, and a second substrate; and In step S2, after the laminated body rolled from the roll of raw material has undergone a process including cutting it to a specified width and peeling off one of the first substrate and the second substrate, it is wound onto a core to obtain the wound body of the adhesive film for circuit connection. In the process S2, only one step is performed to take the laminate after one of the first substrate and the second substrate has been peeled off.

2. The method for manufacturing a wound body of an adhesive film for circuit connection according to claim 1, wherein, In process S2, the second substrate is peeled off.

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

4. A wound body of an adhesive film for circuit connection, comprising a wound body having an adhesive film for circuit connection having a substrate and an adhesive layer disposed on the substrate wound on a core, wherein, The adhesive layer includes a first adhesive layer comprising a thermosetting composition and a second adhesive layer comprising conductive particles and a thermosetting composition. When the adhesive film for circuit connection is wound out from the winding body, the root mean square height of the surface of the adhesive layer opposite to the substrate 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 wound out from the winding body, the kurtosis of the surface of the adhesive layer opposite to the substrate 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, in sequence, the substrate, the first adhesive layer, and the second adhesive layer.

8. A raw material for forming an adhesive film for circuit connection, comprising a winding body for winding a laminate onto a core, the laminate having sequentially a first substrate, a first adhesive layer comprising a thermosetting composition, a second adhesive layer comprising conductive particles and a thermosetting composition, and a second substrate.

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