Method for producing structure and adhesive film

Abstract

Provided are: a method for producing a structure that has excellent adhesive strength using a two-part curing adhesive; and an adhesive film. This method for producing a structure uses a two-part curing adhesive that includes a first agent and a second agent, the method comprising: an arrangement step for arranging, between a first component and a second component, a first resin layer and a second resin layer alternately in two or more layers, the first resin layer containing the first agent and having a thickness of not less than 1 μm and less than 5 μm, the second resin layer containing the second agent and having a thickness of not less than 1 μm and less than 5 μm; and a pressing step for pressing the first component and the second component. Consequently, a reaction between the first agent and the second agent is started in the vicinity of the first component and the second component at the time of pressing, and thus excellent adhesive strength can be achieved.

Description

Method for manufacturing structure and adhesive film

[0001] The present technology relates to a method for manufacturing a structure in which a first component and a second component are bonded using a two-component curing adhesive, and an adhesive film. This application claims priority based on Japanese Patent Application No. 2023-122065, filed in Japan on July 26, 2023, which is incorporated herein by reference.

[0002] For example, in mounting electronic components, an adhesive film is sandwiched between opposing electronic components and hardened by heating and pressing with a tool (see, for example, Patent Document 1). In such mounting methods, lower temperatures are strongly desired because damage caused by heat is easily avoided as electronic components become smaller and thinner.

[0003] When using one-component curing adhesives that bond at low temperatures, they must be stored in a freezer, for example, and are difficult to handle.On the other hand, two-component curing adhesives can be stored for long periods of time while maintaining the ability to bond at low temperatures, because the reaction does not occur unless the two liquids are mixed.

[0004] However, when two-component curing adhesives are used in liquid form, they must be applied to the bonding area using a syringe or the like, which requires spreading or coating when used on a surface.Furthermore, two-component curing adhesives cannot achieve stable performance and it is difficult to obtain excellent adhesive strength unless the two liquid agents are mixed uniformly at a precise ratio.

[0005] JP 2016-056274 A

[0006] The present technology solves the above-mentioned problems and provides a method for manufacturing a structure and an adhesive film that can obtain excellent adhesive strength using a two-component curing adhesive.

[0007] As a result of extensive research into the above-mentioned problems, the present inventors have found that the above-mentioned problems can be solved by the following technology, and have thus completed the present technology.

[0008] [1] A method for manufacturing a structure using a two-component curing adhesive containing a first component and a second component, the method comprising: a disposing step of disposing two or more alternate layers of a first resin layer containing the first component and having a thickness of 1 μm or more but less than 5 μm and a second resin layer containing the second component and having a thickness of 1 μm or more but less than 5 μm between a first component and a second component; and a pressing step of pressing the first component and the second component together. [2] A method for manufacturing a structure according to [1], in the disposing step, an adhesive film is prepared by laminating two or more alternate layers of the first resin layer and the second resin layer, and then disposing the adhesive film between the first component and the second component. [3] A method for manufacturing a structure according to [1], in the disposing step, the first resin layer or the second resin layer is attached to at least one of the first component and the second component, and then the first resin layer and the second resin layer are arranged alternately so as to form two or more layers. [4] The method for manufacturing a structure according to any one of [1] to [3], wherein the first resin layer and the second resin layer are alternately arranged in three or more layers in the disposing step. [5] The method for manufacturing a structure according to any one of [1] to [3], wherein the first agent is a silane-based compound that reacts with an aluminum chelate compound to generate aluminum chelate-silanol active species, the second agent is an aluminum chelate compound that reacts with a silane-based compound to generate aluminum chelate-silanol active species, the first resin layer further contains a cationically polymerizable compound, and the second resin layer further contains a cationically polymerizable compound. [6] The method for manufacturing a structure according to any one of [1] to [3], wherein at least one of the first resin layer and the second resin layer contains conductive particles. [7] The method for manufacturing a structure according to any one of [1] to [3], wherein the first resin layer and the second resin layer are arranged at a temperature of 40°C or less in the disposing step. [8] The method for manufacturing a structure according to any one of [1] to [3], wherein in the pressing step, the first component and the second component are pressed together at a temperature of 40° C. or less. [9] The method for manufacturing a structure according to any one of [1] to [3], further comprising a storage step of storing the first resin layer and the second resin layer at room temperature, respectively, before the placement step.

[10] The method for producing a structure according to [5], wherein the aluminum chelate compound contains aluminum monoacetylacetonate bis(ethylacetoacetate), and the silane compound contains tris(tert-pentoxy)silanol and tris(tert-butoxy)silanol.

[11] An adhesive film using a two-component curing adhesive containing a first part and a second part, the adhesive film containing the first part and having a thickness of 1 μm or more and less than 5 μm.

[12] The adhesive film according to

[11] , wherein the first part is a silane-based compound that reacts with the aluminum chelate compound to generate aluminum chelate-silanol active species, and further contains a cationic polymerizable compound.

[13] An adhesive film using a two-component curing adhesive containing a first part and a second part, the adhesive film containing the second part and having a thickness of 1 μm or more and less than 5 μm.

[14] The adhesive film according to

[13] , wherein the second agent is an aluminum chelate compound that reacts with a silane compound to generate aluminum chelate-silanol active species, and further contains a cationic polymerizable compound.

[15] A member provided with individual pieces of the adhesive film according to

[11] or

[12] .

[16] A member provided with individual pieces of the adhesive film according to

[13] or

[14] .

[17] A member provided with individual pieces of the adhesive film according to

[11] or

[12] and individual pieces of the adhesive film according to

[13] or

[14] separately.

[0009] According to this technology, for the first and second agents that begin a curing reaction upon contact, a resin layer of a predetermined thickness containing the first agent and a resin layer of a predetermined thickness containing the second agent are formed in advance, and these are arranged alternately in two or more layers to form an adhesive film when pressed.This allows the reaction between the first agent and the second agent to begin near the first part and the second part when pressed, thereby obtaining excellent adhesive strength.

[0010] Fig. 1 is a cross-sectional view showing an example of the configuration of an adhesive film according to an embodiment of the present technology. Fig. 2 is a cross-sectional view showing a state in which a first resin layer is provided on a terminal of a first electronic component and a second resin layer is provided on a terminal of a second electronic component. Fig. 3 is a cross-sectional view showing a state in which a third resin layer is provided on the first resin layer.

[0011] Hereinafter, embodiments of the present technology will be described in detail with reference to the drawings in the following order: 1. Method for manufacturing a structure and adhesive film 2. First embodiment 3. Second embodiment 4. Examples

[0012] 1. Method for Manufacturing a Structure and Adhesive Film [Method for Manufacturing a Structure] A method for manufacturing a structure according to the present technology uses a two-component curing adhesive containing a first agent and a second agent. The method includes an arrangement step of alternately arranging two or more first resin layers containing the first agent and having a thickness of 1 μm or more but less than 5 μm and second resin layers containing the second agent and having a thickness of 1 μm or more but less than 5 μm between a first component and a second component, and a pressing step of pressing the first component and the second component together. This initiates a reaction between the first agent and the second agent near the first component and the second component during pressing, thereby achieving excellent adhesive strength. Furthermore, the present technology allows the first and second agents, which initiate a curing reaction upon contact, to function as an adhesive with a uniform thickness over a planar area by preforming a resin layer containing the first agent and a resin layer containing the second agent. This technology is also effective when used in areas or installation locations where conventional liquid two-component curing adhesives are difficult to work with.

[0013] Two-component curing adhesives are adhesives that cure through a chemical reaction, such as epoxy resin-based, acrylic resin-based, and silicone rubber-based adhesives, and are generally liquid adhesives in which a first component as a base agent and a second component as a curing agent are measured and mixed immediately before use. Among these, two-component curing epoxy adhesives, when combined with a curing agent and additives, can produce a cured product that has excellent adhesion, electrical insulation, heat resistance, chemical resistance, etc.

[0014] Examples of epoxy compounds include glycidyl ether type, glycidyl ester type, glycidyl amine type, and oxide type. Examples of epoxy curing agents include aliphatic polyamines, aromatic polyamines, polyamidoamines, acid anhydride curing agents, phenolic resin curing agents, polymercaptan curing agents, and catalyst curing agents.

[0015] Among these, it is preferable to use an aluminum complex-silanol compound composite catalyst, with the first agent being a silane compound and the second agent being an aluminum chelate compound, which allows a cationically polymerizable compound such as an epoxy compound to be blended into both the first and second resin layers, and allows the first and second agents to be mixed uniformly at a precise blending ratio.

[0016] Aluminum chelate compounds are complex compounds in which three β-ketoenolate anions are coordinated to aluminum, and when used with silanol compounds, they form Brønsted acids that can rapidly cure cationic polymerizable compounds at low temperatures. Brønsted acids are highly active, allowing cationic polymerizable compounds to rapidly cure at room temperature.

[0017] In the arrangement step, examples of configurations in which two or more first resin layers and second resin layers are arranged alternately include two layers of the first resin layer and the second resin layer, three layers in which the first resin layer, the second resin layer, and the first resin layer are arranged in this order, three layers in which the second resin layer, the first resin layer, and the second resin layer are arranged in this order, four layers in which the first resin layer, the second resin layer, the first resin layer, and the second resin layer are arranged in this order, and five layers in which the first resin layer, the second resin layer, the first resin layer, the second resin layer, and the first resin layer are arranged in this order.

[0018] In the disposing step, it is preferable that the main pressure bonding is started within 60 seconds after the surfaces of the first resin layer and the second resin layer first come into contact with each other in an environment at a temperature of 23° C. or less, thereby suppressing the effect of the adhesive strength on the reaction at the interface between the first resin layer and the second resin layer.

[0019] The thickness of the first resin layer and the second resin layer is less than 5 μm, preferably 4 μm or less, more preferably 3 μm or less, and even more preferably 2 μm or less. Furthermore, the lower limit of the thickness of the first resin layer and the second resin layer is not particularly limited as long as they can be formed into films, but from the viewpoint of ease of handling, it is preferably 1.0 μm or more, more preferably 1.2 μm or more, and even more preferably 1.5 μm or more. If the thickness is less than 1.0 μm, there is a risk of problems such as uneven film thickness, but it may be used as long as there are no problems in use. The first resin layer or the second resin layer may be formed by laminating first resin layers or second resin layers together. In this case, the thickness of the first resin layers or second resin layers may be within the same range as the thickness of the first resin layer and the second resin layer described above. The thickness of the resin layer can be measured using a known micrometer or digital thickness gauge (e.g., Mitutoyo Corporation: MDE-25M, minimum display 0.0001 mm). The thickness of the resin layer may be determined by measuring at 10 or more locations and averaging the measured values.

[0020] Furthermore, because the thickness of each resin layer of the adhesive film is extremely thin, less than 5 μm, heat conducts easily even at low temperatures, making it easier to avoid damage caused by heat to electronic components. Furthermore, the extremely thin thickness of each resin layer is extremely effective in reducing the height of terminals. Furthermore, because multiple thin films are provided on electronic components, it is possible to accommodate cases where the terminal heights of electronic components vary. In recent years, multiple second electronic components are sometimes provided on a single first electronic component (e.g., a substrate). In this case, the outer shape, terminal height, and terminal layout (including electrode shape, L / S, etc.) of the second electronic component are not limited to one type, but may be multiple types. In other words, the outer shape and dimensions of the film may differ depending on the mounting location. In this case, if the outer dimensions are common, the same film can be cut and provided; if they are not common, it can be pre-cut into individual pieces. That is, individual pieces of adhesive film containing the first agent and individual pieces of adhesive film containing the second agent may be separately provided on one component, or individual pieces of adhesive film containing the first agent and individual pieces of adhesive film containing the second agent may be separately provided on one substrate. Furthermore, even if there are multiple types of electronic components, the storage life of each resin layer of the adhesive film is long enough before the placement process, making it easier to meet complex requirements during the manufacture of structures than conventional adhesive films. Furthermore, according to this technology, the combination of resin layers can be selected during the manufacture of the structure, which allows for minor specification changes to the manufacturing equipment of the structure, contributing to the manufacture of various structures and reducing the investment costs of the manufacturing equipment of the structure.

[0021] Furthermore, when the first component and the second component are electronic components, the upper limit of the total thickness of two or more alternating layers of first and second resin layers is preferably 1.5 times or less, more preferably 1.3 times or less, and even more preferably 1.1 times or less, the sum of the heights of the opposing bumps and electrodes. Alternatively, the upper limit of the total thickness of two or more alternating layers of first and second resin layers is preferably 5 μm or less plus the height of the opposing bumps and electrodes, more preferably 3 μm or less plus the height of the opposing bumps and electrodes, and even more preferably 2 μm or less plus the height of the opposing bumps and electrodes. Furthermore, the lower limit of the total thickness of two or more alternating layers of first and second resin layers is preferably 0.5 times or more the sum of the heights of the bumps and electrodes. Because a thinner total thickness facilitates repair, in practice, the lower limit of the total thickness is preferably 1 time or more the sum of the heights of the bumps and electrodes. This initiates a reaction between the first and second parts when pressed, accelerating curing and resulting in excellent adhesive strength (adhesion and adhesion).

[0022] If the thicknesses of the first and second resin layers are too large, the reaction between the first and second parts will not start near the first and second parts, which will tend to reduce adhesive strength and make it difficult to obtain high die shear strength.On the other hand, if the thicknesses of the first and second resin layers are too small, it will tend to make it difficult to form film-like resin layers.

[0023] The first and second components are not particularly limited, but examples thereof include materials used in electronic components, such as metal, plastic, and glass. Furthermore, when the first and second components are electronic components, examples of the first electronic component include plastic substrates, glass substrates, and printed wiring boards (PWBs) for LCD (Liquid Crystal Display) panel applications and organic light-emitting diode (OLED) panel applications. Examples of the second electronic component include flexible printed circuits (FPCs) such as integrated circuits (ICs) and chip-on-film (COFs), and tape carrier package (TCP) substrates. In addition to these, the present technology can also be applied to applications other than electronic components as long as the adhesive properties are met. Therefore, the first and second components may be made of, for example, metal, plastic (resin products), glass, ceramics, cement concrete, wood, or a combination thereof.

[0024] At least one of the first and second resin layers may contain conductive particles. The conductive particles may be dispersed in the resin layer, may have regularity, or may be arranged in a regular pattern such as a lattice or a staggered pattern in a planar view. Examples of lattice patterns include an oblique lattice, a hexagonal lattice, a square lattice, a rectangular lattice, and a parallelepiped lattice. This allows the surface density of the conductive particles to be uniform, thereby improving connection reliability.

[0025] The conductive particles may be any known conductive particles used in conductive films. Examples include particles of various metals or metal alloys such as nickel, iron, copper, aluminum, tin, lead, chromium, cobalt, silver, and gold; particles of metal oxides, carbon, graphite, glass, ceramics, and plastics coated with a metal; and particles that have been further insulated by coating the surface of an insulating thin film or by attaching insulating fine particles. Two or more of these may be mixed. In the case of resin particles coated with a metal, examples of the resin particles that can be used include particles of epoxy resin, phenolic resin, acrylic resin, acrylonitrile-styrene (AS) resin, benzoguanamine resin, divinylbenzene resin, and styrene resin.

[0026] From the viewpoint of forming a resin layer by coating, the thickness of the resin layer containing conductive particles is preferably 0.6 times or more, more preferably 0.8 times or more, the average particle size of the conductive particles. That is, the upper limit of the average particle size of the conductive particles is preferably 6.7 μm or less, more preferably 6 μm or less, and even more preferably 5 μm or less. In practical use, it is desirable that it be equal to or less than the thickness of the first resin layer and the second resin layer. Furthermore, the lower limit of the average particle size of the conductive particles is preferably 1 μm or more, more preferably 1.5 μm or more, and even more preferably 2 μm or more. The average particle size can be the particle size at 50% of the integrated value measured using an imaging particle size distribution meter (for example, FPIA-3000, manufactured by Malvern Instruments).

[0027] The resin layer containing conductive particles is preferably one layer, but may be two or more layers. From the viewpoint of capturing the conductive particles during connection, the resin layer containing conductive particles is preferably a first layer attached to the first electronic component or the second electronic component, or a second layer provided on the first layer.

[0028] The adhesive film consisting of the first resin layer or the second resin layer may be a piece of film processed into a predetermined shape by applying the method described in JP 2020-198422 A. Processing methods include punching out the film of the first resin layer or the second resin layer, laser processing in which unnecessary portions of the film of the first resin layer or the second resin layer formed on the release-treated film are removed with a laser, and printing in which the resin composition of the first resin layer or the second resin layer is uniformly applied to the release-treated film.

[0029] Furthermore, the adhesive film consisting of the first resin layer or the second resin layer is preferably provided on a release-treated substrate film, regardless of whether it is an individual piece or not, and the adhesive film and the substrate film may be wound around a reel to form a wound body. The lower limit of the substrate film thickness is preferably 12 μm or more, and the upper limit of the substrate film thickness is preferably 100 μm or less. In this technology, the thickness of the adhesive film is thinner than the thickness of the substrate film, so even when wound into a wound body (wound around a roll), the effects of blocking and protrusion are extremely reduced. This avoids defects during manufacturing and contributes greatly to productivity. Due to factors such as shipping, handling, and installation in manufacturing equipment, the wound body is preferably 5 m or more long. Furthermore, since handling is difficult if the length of the wound body is too long, the upper limit is 5,000 m or less, preferably 1,000 m or less.

[0030] The shape of the film piece is not particularly limited, and may be, for example, matched to the shapes of the first and second components, or, if the first and second components are electronic components, matched to the shape of the terminal rows of the electronic components. Specific examples include a rectangular shape corresponding to the terminal rows, a shape with an opening surrounding the periphery of the components, etc.

[0031] The individual film of the first resin layer or the second resin layer formed on the release-treated film may be transferred onto the first component or the second component using a laser lift-off (LLO) device, or may be transferred onto the individual film and laminated. Alternatively, lamination may be performed using a stamp material. This can improve the productivity of the structure.

[0032] [Adhesive Film] Next, the resin compositions constituting each resin layer of the adhesive film will be described. The resin composition constituting the first resin layer comprises a cationically polymerizable compound, a silane-based compound as a first agent, and a film-forming resin. The resin composition constituting the second resin layer comprises a cationically polymerizable compound, an aluminum chelate compound as a second agent, and a film-forming resin.

[0033] (Cationically Polymerizable Compound) As the cationically polymerizable compound, at least one compound selected from epoxy compounds and oxetane compounds can be used.

[0034] It is preferable to use an epoxy compound having five or fewer functionalities. Examples of epoxy compounds having five or fewer functionalities include glycidyl ether-type epoxy compounds, glycidyl ester-type epoxy compounds, alicyclic epoxy compounds, bisphenol A-type epoxy compounds, bisphenol F-type epoxy compounds, dicyclopentadiene-type epoxy compounds, novolac phenol-type epoxy compounds, biphenyl-type epoxy compounds, and naphthalene-type epoxy compounds. One of these can be used alone, or two or more can be used in combination. A specific example of a commercially available alicyclic epoxy resin is "Celloxide 8000" manufactured by Daicel Corporation.

[0035] Examples of oxetane compounds include biphenyl-type oxetane compounds, xylylene-type oxetane compounds, silsesquioxane-type oxetane compounds, ether-type oxetane compounds, phenol novolac-type oxetane compounds, and silicate-type oxetane compounds, and these can be used alone or in combination of two or more. A specific example of a commercially available biphenyl-type oxetane compound is "OXBP" available from UBE Corporation.

[0036] The content of the cationically polymerizable compound is preferably 10 to 70 wt %, more preferably 20 to 50 wt %. If the content of the cationically polymerizable compound is too high, the curing shrinkage tends to increase.

[0037] (Aluminum chelate compounds) Examples of aluminum chelate compounds include aluminum tris(acetylacetonate), aluminum tris(ethylacetoacetate), aluminum monoacetylacetonate bis(ethylacetoacetate), aluminum monoacetylacetonate bisoleylacetoacetate, ethylacetoacetate aluminum diisopropylate, alkylacetoacetate aluminum diisopropylate, etc. A specific example of commercially available aluminum monoacetylacetonate bis(ethylacetoacetate) is "Aluminum Chelate D" available from Kawaken Fine Chemicals Co., Ltd.

[0038] The content of the aluminum chelate compound is preferably 1 to 50 wt %, more preferably 1 to 20 wt %, and even more preferably 1 to 5 wt %. The content of the aluminum chelate compound is preferably 2 to 4 parts by mass per 100 parts by mass of the total resin composition constituting the resin layer excluding the aluminum chelate compound. If the content of the aluminum chelate compound is too low, the resin will not cure sufficiently, whereas if the content is too high, the resin properties (e.g., flexibility) of the cured product of the composition will tend to decrease.

[0039] (Silane Compound) The silane compound can cooperate with the aluminum chelate compound to initiate cationic polymerization and promote curing. Examples of the silane compound include a highly sterically hindered silanol compound and a silane coupling agent having one to three lower alkoxy groups in the molecule.

[0040] Specific examples of silanol compounds include tris(tert-pentoxy)silanol, tris(tert-butoxy)silanol, bis(tert-butoxy)(isopropoxy)silanol, etc. Specific examples of silane coupling agents include vinyltris(β-methoxyethoxy)silane, vinyltriethoxysilane, vinyltrimethoxysilane, γ-styryltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, etc.

[0041] The content of the silane compound is preferably 1 to 50 wt %, more preferably 1 to 20 wt %, and even more preferably 3 to 10 wt %. The content of the silane compound is preferably 4 to 8 parts by mass per 100 parts by mass of the total resin composition constituting the resin layer excluding the silane compound. If the content of the silane compound is too low, insufficient curing will occur, and if the content is too high, the resin properties after curing tend to deteriorate.

[0042] (Film-forming resin) The resin composition preferably contains a film-forming resin. The film-forming resin corresponds to a high-molecular-weight resin, for example, having an average molecular weight of 10,000 or more, and from the viewpoint of film-forming properties, the average molecular weight is preferably about 10,000 to 80,000. Examples of film-forming resins include various resins such as phenoxy resin, epoxy resin, polyester resin, polyurethane resin, polyester urethane resin, acrylic resin, polyimide resin, and butyral resin. These may be used alone or in combination of two or more. Among these, phenoxy resin is preferably used from the viewpoint of film formation state, connection reliability, etc. The content of the film-forming resin is preferably 20 to 80 wt %, more preferably 30 to 60 wt %.

[0043] (Other Additives) The resin composition may also contain an inorganic filler. Examples of inorganic fillers that can be used include silica, talc, titanium oxide, calcium carbonate, and magnesium oxide. The inorganic filler may be used alone or in combination of two or more types. The content of the inorganic filler is preferably 1 to 50 wt %, and more preferably 3 to 20 wt %. The thermal cationic polymerization resin composition may also contain pigments, antistatic agents, and the like, as necessary.

[0044] In an adhesive film including such a first resin layer and a second resin layer, the layer containing the aluminum chelate compound and the layer containing the silane compound are separated, so that the film can have excellent storage stability. Furthermore, the reaction between the aluminum chelate compound and the silane compound is initiated when the adhesive film is pressed, so that the film can have excellent adhesive strength even at low temperatures.

[0045] Furthermore, the minimum melt viscosity of the first resin layer or the second resin layer is preferably 100 Pa s or more. This minimum melt viscosity can be determined, for example, using a rotational rheometer (manufactured by TA Instrument) with a measurement pressure of 5 g maintained constant and a measurement plate with a diameter of 8 mm. More specifically, it can be determined at a temperature range of 30 to 200 ° C, a heating rate of 10 ° C / min, a measurement frequency of 10 Hz, and a load fluctuation of 5 g on the measurement plate. When conductive particles are sandwiched during connection, the conductive particle-containing layer containing the conductive particles is designed to have lower fluidity than the layers other than the conductive particle-containing layer in order to suppress unnecessary resin flow. In this technology, when multiple resin layers are laminated, the fluidity of only the layer directly above the conductive particle-containing layer can be set low, minimizing the effect of capture due to resin flow (for example, since a layer similar to that in JP 2023-051504 A can be provided, unnecessary movement of the conductive particles is expected to be suppressed to a similar extent). This reduces the resistance of the resin when sandwiching the conductive particles, eliminating the need to heat the conductive particle-containing layer to a predetermined temperature or higher to impart fluidity to the resin during connection. Furthermore, since the thickness of the resin layer, not just the conductive particle-containing layer, is thin relative to the substrate, problems such as overflow and blocking are less likely to occur, and productivity in the production of connection structures can be improved.

[0046] Furthermore, because the resin layer reacts upon contact between the first and second components, there is no need to calculate the lifespan of the film during production, resulting in excellent storage stability. This is also an advantage during the connection process. Since the storage period for each film is up to the stage prior to the connection process, the lack of contact and reaction reduces the labor required for component management during the connection process. While this sophisticated design of the resin layer was previously performed during film manufacturing, this technology allows it to be performed during the film placement process, which precedes the connection process. In other words, unlike the conventional method of setting the resin layer configuration in advance during film manufacturing, this technology allows for multiple combinations of film layer configurations to be selected during the placement process. Furthermore, this technology allows for minor specification changes (e.g., increasing or decreasing thickness based on external conditions such as tool temperature or environmental temperature) to be made during the process, enabling the creation of a stable production system for connection structures.

[0047] Hereinafter, the first and second embodiments will be described using an aluminum complex-silanol compound composite catalyst as an example, in which a first resin layer contains a silane compound as a first agent, and a second resin layer contains an aluminum chelate compound as a second agent.

[0048] 2. First Embodiment A method for manufacturing a structure according to a first embodiment includes a placement step of preparing an adhesive film in which two or more layers of first resin layers and second resin layers are alternately laminated, and then placing the adhesive film between a first component and a second component, and a pressing step of pressing the first component and the second component together. That is, in the placement step in the first embodiment, an adhesive film in which the first resin layer and the second resin layer are laminated in advance is prepared, and the adhesive film is attached to the first component or the second component.

[0049] In the disposing step, the first resin layer and the second resin layer are preferably disposed at a temperature of 40° C. or lower. Specifically, the temperature of the temporary attachment tool or the laminator used for lamination is preferably 40° C. or lower. By laminating the first resin layer and the second resin layer at a low temperature, the cationic polymerization reaction caused by the aluminum chelate-silanol active species can be limited to the interface between the first resin layer and the second resin layer.

[0050] It is also preferable to further include a storage step of storing the first resin layer and the second resin layer at room temperature before the placement step. By storing the first resin layer and the second resin layer at room temperature in advance, the lamination of the first resin layer and the second resin layer in the placement step can be considered as the initiation of a cationic polymerization reaction caused by the aluminum chelate-silanol active species, and the time until the first component and the second component are pressed together can be easily calculated. Here, room temperature refers to the temperature range of 5 to 35°C specified in JIS Z 8703, which relates to the standard conditions of the test location. The first resin layer and the second resin layer require minimal equipment for storage, which offers overall economic and environmental advantages.

[0051] In the pressing step, the first and second components are pressed together at a temperature of preferably 230° C. or less, more preferably 180° C. or less, and even more preferably 130° C. or less. Pressing the first and second components together at a low temperature can prevent damage to the first and second components due to heat.

[0052] 1 is a cross-sectional view showing an example of the configuration of an adhesive film according to an embodiment of the present technology. As shown in Fig. 1, the adhesive film includes resin layers A1 and A2 as outermost layers, and a resin layer B3 laminated between the resin layers A1 and A2.

[0053] In a first configuration example of the adhesive film, the resin layer A1 and the resin layer A2 contain a cationically polymerizable compound and an aluminum chelate compound, and the resin layer B3 contains a cationically polymerizable compound and a silane-based compound. That is, in the first configuration example, the resin layer A1 and the resin layer A2 are the first resin layer described above, and the resin layer B3 is the second resin layer described above.

[0054] In a second configuration example of the adhesive film, the resin layer A1 and the resin layer A2 contain a cationically polymerizable compound and a silane-based compound, and the resin layer B3 contains a cationically polymerizable compound and an aluminum chelate compound. That is, in the second configuration example, the resin layer A1 and the resin layer A2 are the second resin layer described above, and the resin layer B3 is the first resin layer described above.

[0055] The thicknesses of the resin layers A1, A2, and B3 are less than 5 μm, preferably 4 μm or less, more preferably 3 μm or less, and even more preferably 2 μm or less, similar to the thicknesses of the first and second resin layers described above. The lower limit of the thicknesses of the resin layers A1, A2, and B3 is preferably 1.0 μm or more, more preferably 1.2 μm or more, and even more preferably 1.5 μm or more, similar to the thicknesses of the first and second resin layers described above.

[0056] As a result, when the adhesive film is pressed, the outermost resin layers A1 and A2, which are located near the adherend, and B3 mix together, initiating a reaction between the aluminum chelate compound and the silane compound, thereby improving the adhesive strength.

[0057] 3. Second Embodiment A method for manufacturing a structure according to a second embodiment includes an arrangement step in which a first resin layer or a second resin layer is attached to at least one of a first component and a second component, and then the first resin layer and the second resin layer are alternately arranged to form two or more layers, and a pressing step in which the first component and the second component are pressed together. That is, in the arrangement step according to the second embodiment, the first resin layer or the second resin layer is first attached to at least one of the first component and the second component, and in the case of three or more layers, a first resin layer or a second resin layer is further laminated. For example, in the case of two layers, a first resin layer and a second resin layer, the first resin layer may be attached to the first component and the second resin layer may be attached to the second component, or the first resin layer may be attached to the first component and the second resin layer may be laminated on the first resin layer. Also, for example, in the case of three layers, a first resin layer may be attached to a first component, a first resin layer may be attached to a second component, and a second resin layer may be laminated on top of the first resin layer.

[0058] In the disposing step, the first resin layer and the second resin layer are preferably disposed at a temperature of 40° C. or less. Specifically, the temperature of the temporary attachment tool or the laminator used for lamination is preferably 40° C. or less. By disposing the first resin layer and the second resin layer at a low temperature, the cationic polymerization reaction caused by the aluminum chelate-silanol active species can be limited to the interface between the first resin layer and the second resin layer.

[0059] Preferably, the method further includes a storage step of storing the first and second resin layers at room temperature before the placement step. By storing the first and second resin layers at room temperature in advance, the placement of the first and second resin layers in the placement step can be considered as the initiation of a cationic polymerization reaction caused by the aluminum chelate-silanol active species, allowing for a simple back-calculation of the time required to press the first and second components together. Here, room temperature refers to the temperature range of 5 to 35°C as defined in JIS Z 8703, which is related to the standard conditions at the test location.

[0060] In addition, in the pressing step, it is preferable to press the first component and the second component together at a temperature of 40° C. or less. Pressing the first component and the second component together at a low temperature can prevent damage to the first component and the second component due to heat.

[0061] The forming step (A) of forming the resin layer A and the resin layer B, and the pressing step (B) of pressing the first electronic component and the second electronic component together will be described below with reference to Fig. 2 and Fig. 3. Fig. 2 is a cross-sectional view schematically showing a state in which a resin layer A21 is provided on the terminal of the first electronic component and a resin layer A22 is provided on the terminal of the second electronic component, and Fig. 3 is a cross-sectional view schematically showing a state in which a resin layer B23 is provided on the resin layer A21.

[0062] Resin layer A21, resin layer A22, and resin layer B23 are similar to the resin layer A1, resin layer A2, and resin layer B3 described above, respectively, and therefore will not be described here. That is, in the first configuration example, resin layer A21 and resin layer A22 are the first resin layer described above, and resin layer B23 is the second resin layer described above, and in the second configuration example, resin layer A21 and resin layer A22 are the second resin layer described above, and resin layer B23 is the first resin layer described above.

[0063] [Forming Step (A)] As shown in FIG. 2 , in the forming step (A), a resin layer A21 is provided on the terminals of the first electronic component 11, and a resin layer A22 is provided on the terminals of the second electronic component 12. The forming step (A) may be a step of forming a film of the resin composition constituting the resin layer A21 and the resin composition constituting the resin layer B22 on the first electronic component 11 and the second electronic component 12, respectively, before connection. Alternatively, the forming step (A) may be a temporary attachment step of attaching the aforementioned resin layer A1 film and resin layer A2 film to the first electronic component 11 and the second electronic component 12, respectively, at low temperature and low pressure. Alternatively, the forming step (A) may be a lamination step of laminating the resin layer A21 film and resin layer A22 film on the first electronic component 11 and the second electronic component 12, respectively. Among these, the temporary bonding process can provide a resin layer A21 and a resin layer A22 on the first electronic component 11 and the second electronic component 12, respectively, under known conditions of use, and requires only minimal changes, such as changing the tools, from the previous equipment, thereby achieving economic benefits.

[0064] The thickness of the resin layer A21 and the resin layer A22 is less than 5 μm, preferably 4 μm or less, more preferably 3 μm or less, and even more preferably 2 μm or less, similar to the thickness of the first resin layer and the second resin layer described above. The lower limit of the thickness of the resin layer A21 and the resin layer A22 is preferably 1.0 μm or more, more preferably 1.2 μm or more, and even more preferably 1.5 μm or more, similar to the thickness of the first resin layer and the second resin layer described above.

[0065] [Pressing Process (B)] In the pressing process (B), first, as shown in FIG. 3, a resin layer B23 is provided on the resin layer A21. The method for providing the resin layer B23 may be, as in the forming process (A), a process in which a resin composition constituting the resin layer B23 is formed into a film on the resin layer A21 before connection. Alternatively, the method may be a temporary attachment process in which a film of the resin layer B23 is attached to the resin layer A21 at low temperature and low pressure. Alternatively, the method may be a lamination process in which a film of the resin layer B23 is laminated on the resin layer A21. Among these, the temporary attachment process can provide an adhesive film on the resin layer A21 under known operating conditions, and requires only minimal changes from the previous equipment, such as changing tools or modifying the conveying mechanism, resulting in economic benefits.

[0066] Next, a pressure bonding tool heated to a predetermined temperature is used to apply a predetermined pressure and a predetermined time from above the second electronic component 12, thereby connecting the terminals of the first electronic component 11 and the terminals of the second electronic component 12. Furthermore, if at least one of the resin layers A21, A22, and B23 contains conductive particles, the conductive particles are sandwiched and crushed between the terminals of the first electronic component 11 and the terminals of the second electronic component 12, and the binder hardens in this state.

[0067] The predetermined pressure during the heat and pressure application is preferably 1 MPa or more and 150 MPa or less from the viewpoint of preventing wiring cracks in the electronic components. The predetermined temperature is preferably 230°C or less, more preferably 180°C or less, and even more preferably 130°C or less. Light irradiation such as UV may also be used in combination. In this embodiment, since the thickness of each resin layer is thin, the resin of each resin layer can be sufficiently melted even when pressure-bonded at a low temperature.

[0068] Alternatively, thermocompression bonding may be performed with a buffer material interposed between the crimping tool and the second electronic component. The buffer material can reduce variations in pressure and prevent the crimping tool from becoming dirty. The buffer material is a sheet-like elastic or plastic material, such as Teflon (trademark) or silicone rubber.

[0069] According to the method for manufacturing a structure of the second embodiment, the first resin layer and the second resin layer come into contact with each other in the pressing step (B), so that excellent adhesive strength can be obtained without having to consider the reaction at the interface when used as a connecting film.

[0070] The connection structure according to this embodiment comprises a first component, a second component, and a cured film formed by curing two or more layers of alternating first and second resin layers that bond the first and second components together, wherein the first resin layer contains a cationic polymerizable compound and a silane-based compound and has a thickness of 1 μm or more and less than 5 μm, and the second resin layer contains a cationic polymerizable compound and an aluminum chelate compound and has a thickness of 1 μm or more and less than 5 μm.

[0071] In the structure according to this embodiment, the first and second components are connected under low-temperature conditions and have excellent adhesive strength, so that excellent reliability can be obtained even when small or thin electronic components that are susceptible to thermal damage are mounted.

[0072] 3. Example In this example, an anisotropic conductive film was produced by alternately laminating two or more resin layers containing the first and second components using a two-component curing adhesive containing a first component and a second component. A connection structure was then produced using the anisotropic conductive film, and the conduction resistance, adhesive strength, and storage stability were evaluated.

[0073] [Fabrication of Connection Structure] The following evaluation IC and glass substrate were prepared. (Evaluation IC) Outer dimensions: 1.8×20.0 mm Thickness: 0.5 mm Bump specifications: Size: 30×85 μm, distance between bumps: 50 μm, bump heights: 5 μm, 7 μm, 12 μm

[0074] (Glass substrate) Glass material: Corning 1737F Dimensions: 30 x 50 mm Thickness: 0.5 mm Electrode: ITO wiring

[0075] The anisotropic conductive film was cut to an area sufficient for connection, sandwiched between the evaluation IC and the glass substrate, and pressed under pressure bonding conditions of a temperature of 130° C., a pressure of 70 MPa, and a time of 5 seconds to prepare a connection structure for evaluation.

[0076] [Evaluation of Conduction Resistance] The resistance value (Ω) of the connection structure for evaluation was measured when a current of 1 mA was passed using a four-terminal method using a digital multimeter (34401A, manufactured by Agilent Technologies Inc.). The evaluation of the conduction resistance was performed according to the following criteria: A: Maximum resistance value is less than 2Ω B: Maximum resistance value is 2Ω or more and 4Ω or less C: Maximum resistance value is more than 4Ω

[0077] [Evaluation of Adhesion Strength] The die shear strength of the evaluation IC was measured using a die shear tester (4000 series, Nordson Advanced Technologies Co., Ltd.) at a tool speed of 0.2 mm / sec for the evaluation connection structure. The die shear strength was evaluated according to the following criteria: AA: Die shear strength greater than 900 N A: Die shear strength of 600 N or more and 900 N or less B: Die shear strength of 300 N or more and 600 N or less C: Die shear strength less than 300 N

[0078] [Evaluation of storage stability] The resin layer before lamination was subjected to an aging treatment under environmental conditions of a temperature of 40°C for 8 hours. Then, the die shear strength was measured for a connection structure formed using an anisotropic conductive film produced using the aged resin layer. The storage stability was evaluated based on the die shear strength of a connection structure formed using an initial anisotropic conductive film that had not been aged, using the following criteria: AA: Decrease in die shear strength less than 10% A: Decrease in die shear strength 10% to 30% B: Decrease in die shear strength 30% to 50% C: Decrease in die shear strength more than 50%

[0079] [Examples and Comparative Examples] First, resin compositions A1 to A5 containing no conductive particles and resin compositions B1 to B5 containing conductive particles were prepared. Resin layers of predetermined thicknesses were then fabricated using the resin compositions A1 to A5 and B1 to B5. Using the resin layers of predetermined thicknesses, a two-layer anisotropic conductive film was fabricated by laminating a first resin layer and a second resin layer; a three-layer anisotropic conductive film was fabricated by laminating a first resin layer, a second resin layer, and a third resin layer in this order; or a five-layer anisotropic conductive film was fabricated by laminating a first resin layer, a second resin layer, a third resin layer, a fourth resin layer, and a fifth resin layer in this order. The anisotropic conductive film was then sandwiched between an evaluation IC and a glass substrate with the first resin layer facing the glass substrate, and pressed within 60 seconds of laminating the resin layers to fabricate a connection structure.

[0080] Table 1 shows the formulations of resin compositions A1 to A5 that do not contain conductive particles, and Table 2 shows the formulations of resin compositions B1 to B5 that contain conductive particles. Tables 3 to 5 also show the evaluation results of the conduction resistance, die shear strength, and storage stability of the connection structures prepared using the anisotropic conductive films of the Examples and Comparative Examples.

[0081] Phenoxy resin: YP50, Nippon Steel Chemical & Material Co., Ltd. Epoxy resin: YD-019, Nippon Steel Chemical & Material Co., Ltd. Silica filler: Aerosil 805, Nippon Aerosil Co., Ltd. Alicyclic epoxy resin: Celloxide 8000, Daicel Corporation Oxetane compound: OXBP, UBE Corporation Aluminum chelate compound: Aluminum Chelate D, Kawaken Fine Chemicals Co., Ltd. Silanol compound: Tris(tert-pentoxy)silanol (TPS) Conductive particles (resin core metal coated conductive particles): AUL704, Sekisui Chemical Co., Ltd., 4 μmφ

[0082]

[0083]

[0084]

[0085]

[0086]

[0087] In Comparative Example 1, the thickness of the first resin layer was large, so there were areas where the reaction did not proceed sufficiently, and as a result, excellent adhesive strength (adhesion and adhesion) was not obtained.In Comparative Example 2, because Formulation A5 of the first resin layer and Formulation B5 of the second resin layer contained both an aluminum chelate compound and a silanol compound, the curing reaction proceeded, and it was not possible to produce the first resin layer and the second resin layer.

[0088] On the other hand, in Examples 1 to 12, the thicknesses of the first to fifth resin layers were 1 μm or more and less than 5 μm, and the aluminum chelate compound and the silane compound were alternately blended in the resin layers, so that excellent adhesive strength could be obtained under low temperature conditions. Furthermore, it was found that stacking resin layers with thicknesses of 1 μm or more and less than 5 μm can accommodate various bump heights.

[0089] REFERENCE SIGNS LIST 1 Resin layer A, 2 Resin layer A, 3 Resin layer B, 11 First electronic component, 12 Second electronic component, 21 Resin layer A, 22 Resin layer A, 23 Resin layer B

Claims

1. A method for manufacturing a structure using a two-component curing adhesive containing a first agent and a second agent, the method comprising: an arrangement step of arranging two or more layers of a first resin layer containing the first agent and having a thickness of 1 μm or more and less than 5 μm and a second resin layer containing the second agent and having a thickness of 1 μm or more and less than 5 μm alternately between a first component and a second component; and a pressing step of pressing the first component and the second component together.

2. A method for manufacturing a structure as described in claim 1, wherein in the placement step, an adhesive film is prepared by alternately laminating two or more layers of the first resin layer and the second resin layer, and then the adhesive film is placed between the first part and the second part.

3. A method for manufacturing a structure as described in claim 1, wherein in the placement process, the first resin layer or the second resin layer is attached to at least one of the first part and the second part, and then the first resin layer and the second resin layer are alternately placed so as to form two or more layers.

4. A method for manufacturing a structure according to any one of claims 1 to 3, wherein in the arranging step, the first resin layers and the second resin layers are arranged alternately in three or more layers.

5. A method for manufacturing a structure described in any one of claims 1 to 3, wherein the first agent is a silane-based compound that reacts with an aluminum chelate compound to generate aluminum chelate-silanol active species, the second agent is an aluminum chelate compound that reacts with a silane-based compound to generate aluminum chelate-silanol active species, the first resin layer further contains a cationic polymerizable compound, and the second resin layer further contains a cationic polymerizable compound.

6. A method for producing the structure described in any one of claims 1 to 3, wherein at least one of the first resin layer and the second resin layer contains conductive particles.

7. A method for manufacturing a structure according to any one of claims 1 to 3, wherein in the placing step, the first resin layer and the second resin layer are placed at a temperature of 40°C or less.

8. A method for manufacturing a structure according to any one of claims 1 to 3, wherein in the pressing step, the first part and the second part are pressed together at a temperature of 40°C or less.

9. A method for manufacturing a structure according to any one of claims 1 to 3, further comprising a storage step of storing the first resin layer and the second resin layer at room temperature prior to the placement step.

10. The method for producing a structure according to claim 5, wherein the aluminum chelate compound includes aluminum monoacetylacetonate bis(ethylacetoacetate), and the silane compound includes tris(tert-pentoxy)silanol and tris(tert-butoxy)silanol.

11. An adhesive film using a two-component curing adhesive containing a first agent and a second agent, the adhesive film containing the first agent and having a thickness of 1 μm or more and less than 5 μm.

12. The adhesive film according to claim 11, wherein the first agent is a silane-based compound that reacts with an aluminum chelate compound to generate aluminum chelate-silanol active species, and further contains a cationic polymerizable compound.

13. An adhesive film using a two-component curing adhesive containing a first agent and a second agent, the adhesive film containing the second agent and having a thickness of 1 μm or more and less than 5 μm.

14. The adhesive film according to claim 13, wherein the second agent is an aluminum chelate compound that reacts with a silane compound to generate aluminum chelate-silanol active species, and further contains a cationic polymerizable compound.

15. A component provided with individual pieces of the adhesive film according to claim 11 or 12.

16. A component provided with individual pieces of the adhesive film according to claim 13 or 14.

17. A component comprising an individual piece of the adhesive film according to claim 11 or 12, and an individual piece of the adhesive film according to claim 13 or 14, which are separately provided.

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