JP6151412B2 - Anisotropic conductive film, method for manufacturing anisotropic conductive film, method for manufacturing connected body, and connection method - Google Patents

Description

  The present invention relates to an anisotropic conductive film for anisotropically conductively connecting electronic components, and in particular, an anisotropic conductive film having improved connection reliability by eliminating warping of the substrate after the electronic components are connected, and anisotropy The present invention relates to a method for manufacturing a conductive film, a method for manufacturing a connection body, and a connection method.

  Conventionally, liquid crystal display devices are often used as various display means such as televisions, PC monitors, mobile phones, tablet PCs, portable game machines, and in-vehicle monitors. In recent years, in such liquid crystal display devices, so-called COG (chip on glass) in which a liquid crystal driving IC is directly mounted on a substrate of a liquid crystal display panel or a liquid crystal driving circuit from the viewpoints of fine pitch, light weight, and thinning. A so-called FOG (film on glass) that directly mounts the flexible substrate on which the substrate is formed on the substrate of the liquid crystal display panel is employed.

  For example, as shown in FIG. 10, a liquid crystal display device 100 employing a COG mounting system has a liquid crystal display panel 104 that performs a main function for liquid crystal display. The liquid crystal display panel 104 is a glass substrate or the like. And two transparent substrates 102 and 103 facing each other. In the liquid crystal display panel 104, the transparent substrates 102 and 103 are bonded to each other by a frame-shaped seal 105, and the liquid crystal 106 is sealed in a space surrounded by the transparent substrates 102 and 103 and the seal 105. A panel display unit 107 is provided.

  The transparent substrates 102 and 103 have a pair of striped transparent electrodes 108 and 109 made of ITO (indium tin oxide) or the like on both inner surfaces facing each other so as to intersect each other. The transparent substrates 102 and 103 are configured such that a pixel as a minimum unit of liquid crystal display is constituted by the intersection of the transparent electrodes 108 and 109.

  Of the two transparent substrates 102 and 103, one transparent substrate 103 is formed to have a larger planar dimension than the other transparent substrate 102, and the transparent electrode 109 is formed on the edge 103a of the transparent substrate 103 formed to be large. Terminal portion 109a is formed. Further, alignment films 111 and 112 subjected to a predetermined rubbing process are formed on both transparent electrodes 108 and 109, and the initial alignment of liquid crystal molecules is regulated by the alignment films 111 and 112. ing. Further, a pair of polarizing plates 118 and 119 are disposed outside both the transparent substrates 108 and 109, and the vibration direction of transmitted light from the light source 120 such as a backlight is regulated by both the polarizing plates 118 and 119. It has come to be.

  On the terminal portion 109a, a liquid crystal driving IC 115 is thermocompression bonded via an anisotropic conductive film 114. The anisotropic conductive film 114 is a film formed by mixing conductive particles in a thermosetting binder resin, and heat conduction is performed between the two conductors so that the electrical conduction between the conductors is achieved by the conductive particles. And the mechanical connection between the conductors is maintained by the binder resin. The liquid crystal driving IC 115 can perform predetermined liquid crystal display by selectively changing the alignment of the liquid crystal by selectively applying a liquid crystal driving voltage to the pixels. In addition, as the adhesive constituting the anisotropic conductive film 114, the most reliable thermosetting adhesive is usually used.

  When the liquid crystal driving IC 115 is connected to the terminal portion 109a through such an anisotropic conductive film 114, first, the anisotropic conductive film 114 is attached to the terminal portion 109a of the transparent electrode 109 by a temporary crimping means (not shown). Temporarily crimp. Subsequently, after the liquid crystal driving IC 115 is placed on the anisotropic conductive film 114, the liquid crystal driving IC 115 is connected to the terminal together with the anisotropic conductive film 114 by the thermocompression bonding means 121 such as a thermocompression bonding head as shown in FIG. The thermocompression bonding means 121 is caused to generate heat while being pressed toward the portion 109a. Due to the heat generated by the thermocompression bonding means 121, the anisotropic conductive film 114 undergoes a thermosetting reaction, whereby the liquid crystal driving IC 115 is bonded onto the terminal portion 109a via the anisotropic conductive film 114.

JP 2003-195335 A

  By the way, recently, with the trend of thinning and lightening of the display device, the transparent substrates 102 and 103 such as glass substrates are required to be thinned as the liquid crystal display device 100 itself becomes smaller and lighter.

  Here, when the liquid crystal driving IC 115 is COG-mounted on the transparent substrate 103 used for the liquid crystal display panel 104, the mounting region of the edge portion 103a of the transparent substrate 103 is narrowed or the transparent substrate 103 is thinned, so The transparent substrate 103 is likely to warp. When the transparent substrate 103 is warped, color unevenness is generated on the liquid crystal screen around the COG mounting area.

  Since the warpage of the transparent substrate 103 is caused by the generation of stress accompanying the curing shrinkage of the adhesive component of the anisotropic conductive film 114, the warpage is caused by adding a stress relaxation agent such as a rubber component to the adhesive component. A method for reducing the above is also conceivable. However, the addition of the stress relaxation agent reduces the cohesive force of the adhesive component, which may lead to a decrease in connection reliability and an increase in conduction resistance.

  In addition, even when reducing warping by changing the type and amount of adhesive components, mounting conditions, etc., maintaining connection reliability, shortening tact time, and mitigating thermal shock to electronic components such as LCD 115 for liquid crystal drive It is difficult to find the optimum conditions with various factors added.

  Therefore, the present invention provides an anisotropic conductive film that can easily reduce warping after connection in a connection step of an electronic component using the anisotropic conductive film, a method for manufacturing an anisotropic conductive film, and a connection It aims at providing the manufacturing method of a body, and the connection method.

  In order to solve the above-described problems, an anisotropic conductive film according to the present invention has a first insulating adhesive layer and a conductive particle-containing layer in which conductive particles are contained in the insulating adhesive. In addition, bubbles are contained between the conductive particle-containing layer and the first insulating adhesive layer, the conductive particles are regularly arranged, and the bubbles are regularly included. It is.

  In the method for producing an anisotropic conductive film according to the present invention, the conductive particles are arranged in the opening of the mold having the opening, and the adhesive layer is peeled on the surface on which the conductive particles of the mold are arranged. Laminating the adhesive layer of the adhesive film supported by the base material, pressing the adhesive layer from the upper surface of the release base material to the mold, pressing the adhesive layer into the opening, A conductive particle-containing layer in which the conductive particles are peeled off from the mold and regularly adhered to the surface of the adhesive layer by partially exposing the conductive particles from the surface, and the uneven shape corresponding to the mold is molded. Forming, laminating a first insulating adhesive layer on the surface of the conductive particle-containing layer, and regularly forming bubbles between the conductive particle-containing layer and the first insulating adhesive layer. Contain.

  Moreover, the connection body which concerns on this invention uses the said anisotropic conductive film, and the terminal of the 1st electronic component and the terminal of the 2nd electronic component were anisotropically conductive-connected.

  Moreover, the manufacturing method of the connection body which concerns on this invention is the connection body in which the terminal of the 1st electronic component and the terminal of the 2nd electronic component were anisotropically conductive-connected using the said anisotropic conductive film. In the manufacturing method, the first electronic component and the second electronic component are joined to each other by heat pressing or light irradiation through the anisotropic conductive film.

  Further, the connection method according to the present invention is the connection method in which the first electronic component terminal and the second electronic component terminal are anisotropically conductively connected using the anisotropic conductive film. The electronic component and the second electronic component are joined to each other by heat pressing or light irradiation through the anisotropic conductive film.

  According to the present invention, the anisotropic conductive film generates stress as the adhesive component of each layer is cured and contracted, but is contained between the conductive particle-containing layer and the first insulating adhesive layer. The warping of the electronic component can be suppressed by the stress relaxation action by the bubbles.

It is sectional drawing which shows the liquid crystal display device with which one Embodiment of the anisotropic conductive film to which this invention was applied was used. It is sectional drawing which shows one Embodiment of the anisotropic conductive film to which this invention was applied. It is sectional drawing which shows other embodiment of the anisotropic conductive film to which this invention was applied. It is sectional drawing which shows the metal mold | die with which electroconductive particle was arranged in single layer in opening. It is sectional drawing which shows the state by which the adhesive bond layer was laminated on the metal mold | die. It is sectional drawing which shows the electroconductive particle content layer supported by the peeling base material. It is sectional drawing which shows the state by which the 1st insulating adhesive bond layer was laminated on the electroconductive particle content layer. It is sectional drawing which shows the connection state of the electronic component using one Embodiment of the anisotropic conductive film to which this invention was applied. It is a top view which shows the metal mold | die with which electroconductive particle was arranged in opening. It is sectional drawing which shows the conventional liquid crystal display panel. It is sectional drawing which shows the COG mounting process of the conventional liquid crystal display panel.

  Hereinafter, an embodiment of an anisotropic conductive film, a method for manufacturing an anisotropic conductive film, a method for manufacturing a connection body, and a connection method according to the present invention, applied to the manufacture of a liquid crystal display device, is taken as an example. Will be described in detail with reference to FIG. It should be noted that the present invention is not limited to the following embodiments, and various modifications can be made without departing from the scope of the present invention. Further, the drawings are schematic, and the ratio of each dimension may be different from the actual one. Specific dimensions should be determined in consideration of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

[Liquid Crystal Display]
A liquid crystal display device, which is a connection body manufactured using an embodiment of the anisotropic conductive film according to the present invention, has a liquid crystal driving IC directly on a substrate of a liquid crystal display panel by so-called COG (chip on glass) mounting. A flexible substrate on which a liquid crystal driving circuit is formed is mounted directly on the substrate of the liquid crystal display panel by so-called FOG (film on glass) mounting.

  As shown in FIG. 1, the liquid crystal display device includes a liquid crystal display panel 10 that performs a main function for liquid crystal display. In the liquid crystal display panel 10, similarly to the liquid crystal display panel 104, two transparent substrates 11 and 12 made of a glass substrate or the like are disposed to face each other, and the transparent substrates 11 and 12 are bonded to each other by a frame-shaped seal 13. ing. In the liquid crystal display panel 10, the liquid crystal 14 is sealed in a space surrounded by the transparent substrates 11 and 12 to form a panel display unit 15.

  The transparent substrates 11 and 12 have a pair of striped transparent electrodes 16 and 17 made of ITO (indium tin oxide) or the like on both inner surfaces facing each other so as to intersect each other. The transparent substrates 16 and 17 are configured such that a pixel as a minimum unit of liquid crystal display is constituted by the intersection of the transparent electrodes 16 and 17.

  Of the transparent substrates 11 and 12, one transparent substrate 12 is formed to have a larger planar dimension than the other transparent substrate 11, and a liquid crystal driving edge is formed on the edge 12a of the formed transparent substrate 12. A COG mounting unit 20 on which an electronic component 18 such as an IC is mounted is provided, and an FOG mounting unit 22 on which a flexible substrate 21 on which a liquid crystal driving circuit is formed is mounted near the outside of the COG mounting unit 20. ing.

  Note that the liquid crystal driving IC and the liquid crystal driving circuit can perform predetermined liquid crystal display by selectively changing the alignment of the liquid crystal by selectively applying the liquid crystal driving voltage to the pixels. ing.

  In each of the mounting portions 20 and 22, a terminal portion 17a of the transparent electrode 17 is formed. On the terminal portion 17a, an electronic component 18 such as a liquid crystal driving IC and a flexible substrate 21 are thermocompression bonded via an anisotropic conductive film 23. The anisotropic conductive film 23 contains conductive particles, and the electrode of the electronic component 18 or the flexible substrate 21 and the terminal portion 17a of the transparent electrode 17 formed on the edge portion 12a of the transparent substrate 12 are electrically conductive. Electrical connection is made through particles. The anisotropic conductive film 23 is a thermosetting adhesive, and by way of example, the anisotropic conductive film 23 is cured in a state where the conductive particles are crushed by being thermocompression-bonded by a heating and pressing head 3 to be described later. Are connected to the electronic component 18 and the flexible substrate 21.

  Further, an alignment film 24 subjected to a predetermined rubbing process is formed on both the transparent electrodes 16 and 17, and the initial alignment of liquid crystal molecules is regulated by the alignment film 24. In addition, a pair of polarizing plates 25 and 26 are disposed outside the transparent substrates 11 and 12, and these polarizing plates 25 and 26 allow transmitted light from a light source (not shown) such as a backlight to be transmitted. The vibration direction is regulated.

[Anisotropic conductive film]
Next, the anisotropic conductive film 23 will be described. As shown in FIG. 2, the anisotropic conductive film 23 includes a first insulating adhesive layer 30, a second insulating adhesive layer 31, a first insulating adhesive layer 30, and a second insulating adhesive layer 30. A conductive particle-containing layer 34 is sandwiched between the insulating adhesive layers 31 and the conductive particles 32 are contained in the insulating adhesive 33.

[First and second insulating adhesive layers]
Each of the first and second insulating adhesive layers 30 and 31 is a thermosetting adhesive, and an organic resin binder containing a film-forming resin, a thermosetting resin, and a curing agent is a release group. It is supported by the materials 35 and 36. Further, the first and second insulating adhesive layers 30 and 31 may be an adhesive including both thermosetting and photocuring properties, or may be only a photocurable adhesive. Even in this case, a known material can be used as the film-forming resin. The same applies to the release substrates 35 and 36.

  The film-forming resin corresponds to a high molecular weight resin having an average molecular weight of 10,000 or more, and preferably has an average molecular weight of about 10,000 to 80,000 from the viewpoint of film formation. Examples of the film-forming resin include various resins such as an epoxy resin, a phenoxy resin, a polyester urethane resin, a polyester resin, a polyurethane resin, an acrylic resin, a polyimide resin, and a butyral resin, and these may be used alone or 2 You may use combining more than a kind. Among these, phenoxy resin is preferably used from the viewpoints of film formation state, connection reliability, and the like.

  It does not specifically limit as a thermosetting resin, For example, the commercially available epoxy resin, the liquid epoxy resin which has fluidity at normal temperature, an acrylic resin etc. are mentioned.

  Examples of the epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, novolac type epoxy resin, various modified epoxy resins such as rubber and urethane, etc. These are used alone or in combination of two or more. May be. Liquid epoxy resins include bisphenol type epoxy resin, naphthalene type epoxy resin, biphenyl type epoxy resin, phenol novolac type epoxy resin, stilbene type epoxy resin, triphenolmethane type epoxy resin, phenol aralkyl type epoxy resin, naphthol type epoxy resin. Resin, dicyclopentadiene type epoxy resin, triphenylmethane type epoxy resin and the like can be used, and these may be used alone or in combination of two or more.

  There is no restriction | limiting in particular as an acrylic resin, According to the objective, an acrylic compound, liquid acrylate, etc. can be selected suitably. For example, methyl acrylate, ethyl acrylate, isopropyl acrylate, isobutyl acrylate, epoxy acrylate, ethylene glycol diacrylate, diethylene glycol diacrylate, trimethylolpropane triacrylate, dimethylol tricyclodecane diacrylate, tetramethylene glycol tetraacrylate, 2-hydroxy- 1,3-diacryloxypropane, 2,2-bis [4- (acryloxymethoxy) phenyl] propane, 2,2-bis [4- (acryloxyethoxy) phenyl] propane, dicyclopentenyl acrylate, tricyclo Examples include decanyl acrylate, tris (acryloxyethyl) isocyanurate, and urethane acrylate. In addition, what made acrylate the methacrylate can also be used. These may be used individually by 1 type and may use 2 or more types together.

  There is no restriction | limiting in particular in a hardening agent, According to the objective, it can select suitably, For example, the latent hardening agent activated with a heat | fever or light can be used. Examples of the latent curing agent include a cationic curing agent such as a sulfonium salt, an anionic curing agent such as polyamine and imidazole, and a radical curing agent such as an organic peroxide.

  As another additive composition, a silane coupling agent is preferably added. As the silane coupling agent, epoxy, amino, mercapto sulfide, ureido, and the like can be used. Among these, in this Embodiment, an epoxy-type silane coupling agent is used preferably. Thereby, the adhesiveness in the interface of an organic material and an inorganic material can be improved. Moreover, you may add an inorganic filler. As the inorganic filler, silica, talc, titanium oxide, calcium carbonate, magnesium oxide and the like can be used, and the kind of the inorganic filler is not particularly limited. Depending on the content of the inorganic filler, the fluidity can be controlled and the particle capture rate can be improved. A rubber component or the like can also be used as appropriate for the purpose of relaxing the stress of the bonded body.

  The first and second insulating adhesive layers 30 and 31 peel off the organic resin binder obtained by dissolving these film-forming resins, thermosetting resins, curing agents, and other additives with an organic solvent. It forms by apply | coating on the base materials 35 and 36 and volatilizing an organic solvent. In addition, when blending a film-forming resin, a thermosetting resin, a curing agent, and other additives, as an organic solvent for dissolving them, toluene, ethyl acetate, a mixed solvent thereof, and various other organic solvents are used. Can be used.

  As the peeling base materials 35 and 36, base materials, such as a polyethylene terephthalate film generally used in an anisotropic conductive film (ACF), can be used.

[Conductive particle-containing layer]
The first insulating adhesive layer 30 and the second insulating adhesive layer 31 sandwich the conductive particle-containing layer 34. The conductive particle-containing layer 34 is an ultraviolet curable adhesive and contains a film-forming resin, a thermosetting resin, a curing agent, and conductive particles 32.

  As the film-forming resin, thermosetting resin, curing agent, and other additives constituting the conductive particle-containing layer 34, the same materials as those for the first and second insulating adhesive layers 30 and 31 described above are used. be able to.

  Examples of the conductive particles 32 include any known conductive particles used in anisotropic conductive films. Examples of the conductive particles 32 include particles of various metals and metal alloys such as nickel, iron, copper, aluminum, tin, lead, chromium, cobalt, silver, gold, metal oxide, carbon, graphite, glass, ceramic, Examples thereof include those in which the surface of particles such as plastic is coated with metal, or those in which the surface of these particles is further coated with an insulating thin film. In the case where the surface of the resin particle is coated with metal, examples of the resin particle include an epoxy resin, a phenol resin, an acrylic resin, an acrylonitrile / styrene (AS) resin, a benzoguanamine resin, a divinylbenzene resin, a styrene resin, and the like. Can be mentioned.

  The conductive particle-containing layer 34 has a concavo-convex pattern 40 formed on one surface 34 a in contact with the first insulating adhesive layer 30 according to the pattern of the opening 51 of the mold 50 described later. Conductive particles 32 are disposed on the convex portions 40 a of the concave / convex pattern 40. That is, in the conductive particle-containing layer 34, the conductive particles 32 are regularly arranged in a single layer according to the uneven pattern 40. Further, the tops of the conductive particles 32 are exposed at the convex portions 40 a of the concave / convex pattern 40 and are in contact with the first insulating adhesive layer 30.

[Curing degree]
Further, as will be described later, the conductive particle-containing layer 34 is irradiated with ultraviolet rays in advance on one surface 34a after the conductive particles 32 are transferred, and then the first insulating adhesive layer 30 is laminated. . Therefore, the conductive particle-containing layer 34 undergoes a curing reaction on the one surface 34a side. In addition, the conductive particle-containing layer 34 has a degree of cure on the lower side of the conductive particles 32 where the ultraviolet light is blocked, that is, on the other surface 34b side contacting the second insulating adhesive layer 31 from the conductive particles 32. It is lower than the degree of cure of the part.

[Bubble]
Bubbles 41 are contained between the conductive particle-containing layer 34 and the first insulating adhesive layer 30. The bubbles 41 relieve internal stress in the anisotropic conductive film 23 after connection of the electronic component 18 using the anisotropic conductive film 23, thereby preventing the transparent substrate 12 from warping. That is, in the anisotropic conductive film 23, stress is generated as the adhesive components of the layers 30, 31, and 34 are cured and contracted, but between the conductive particle-containing layer 34 and the first insulating adhesive layer 30. The warping of the transparent substrate 12 can be suppressed by the stress relaxation effect of the bubbles 41 contained in the.

  At this time, it is desirable that the position of the bubble 41 is in the vicinity of the conductive particle 32 and is not in contact with the conductive particle 32. This is related to the fact that stress tends to concentrate on the conductive particles 32 during connection. When the bubbles 41 are too close to the conductive particles 32, there is a concern that the stress change may be steep, so that it is relatively preferable that the bubbles 41 are provided with an appropriate distance. This distance is preferably greater than 0.2 times the particle diameter of the closest conductive particles 32, more preferably greater than 0.3 times. In this case, the upper limit of the distance between the bubbles 41 and the conductive particles 32 is not provided because the conductive particles 32 are arranged, and the upper limit varies depending on the interparticle distance. Note that the distance between the bubble 41 and the conductive particle 32 referred to here indicates the shortest distance between the end of the bubble 41 and the end of the conductive particle 32.

  Further, when the distance between the adjacent conductive particles 32 is more than twice the particle diameter, it is desirable that the distance between the conductive particles 32 and the bubbles 41 be in an intermediate region. . Even in this case, the bubbles 41 are preferably separated from the one conductive particle 32 by 0.2 times the particle diameter, more preferably more than 0.3 times. Further, the bubble 41 is preferably present in the central region between the particles of the conductive particles 32 within a range of 0.4 times or more, more preferably within 0.3 times the distance between the intermediate points. It is preferable that it exists in the range. Note that the existence range of the bubbles 41 in this case is 0.5 times at the maximum because the intermediate point is the base point.

  The bubbles 41 are formed on the one surface 34a of the concavo-convex pattern 40 by curing one surface 34a of the conductive particle-containing layer 34 by ultraviolet irradiation and then laminating the first insulating adhesive layer 30. It is contained between the recess 40 b and the first insulating adhesive layer 30. Further, the bubbles 41 are regularly included between the conductive particle-containing layer 34 and the first insulating adhesive layer 30 according to the arrangement of the concave portions 40 b of the concave-convex pattern 40. At this time, a plurality of bubbles 41 and conductive particles 32 are mixed, but the distances between the bubbles 41 and the conductive particles 32 do not necessarily have to be equal. The group of bubbles 41 may exist in a straight line shape or a curved shape, or may have a lattice shape in which such lines intersect. Further, the interval in the bubble group may not be constant, and may be intermittent.

  Note that the bubbles 41 include minute bubbles having a minute size whose maximum length is less than 1 μm. That is, the bubbles 41 are, for example, fine bubbles having a maximum length of less than 1 μm due to the diffusion of bubbles having a size of 1 μm or more by an external force when laminated or stretched in the process of manufacturing the anisotropic conductive film 23. It may be a thing. Thus, even if the bubbles 41 contained in the anisotropic conductive film 23 occupy most of the fine bubbles as described above, the effect of the present invention by the bubbles 41 is not impaired. In addition, if the maximum length of the bubble 41 is larger than 5 μm, it may lead to factors such as entrainment due to resin flow at the time of connection and the generation of voids after the connection, and therefore the maximum length of the bubble 41 should be less than 5 μm. Is desirable.

  Moreover, when the bubble 41 which became the fine bubble is arrange | positioned in the vicinity of the electroconductive particle 32, the effect of the stress relaxation by the bubble 41 is expressed according to it. For example, when the bubbles 41 are unevenly distributed at four locations in the vicinity of the conductive particles 32, the internal stress of the anisotropic conductive film 23 is relaxed while being dispersed at the four locations. For this reason, the curvature of a connection body can be suppressed. As described above, the bubbles 41 include those which are diffused by lamination or stretching in the manufacturing process of the anisotropic conductive film 23 to become fine bubbles, and therefore the shape thereof is not particularly limited.

  Furthermore, as another embodiment of the anisotropic conductive film 123 of the present invention, in order to ensure the independence of the conductive particles 132 and prevent the occurrence of a short circuit, as shown in FIG. The liquid composition 142 may be provided between the insulating adhesive 133 and the conductive particles 132 included in the structure. As the liquid composition 142, known resins and solvents are applied. For example, when a material that contributes to curing at the time of connection is used as the liquid composition 142, a low molecular weight epoxy resin, preferably a monofunctional or bifunctional one, or a low molecular weight acrylic monomer is used. On the other hand, when a material that does not contribute to curing at the time of connection is used as the liquid composition 142, a diluted low molecular weight rubber or phenoxy resin, a tackifier having a molecular weight of several hundred to several thousand, a solvent having a boiling point of 200 ° C. or higher, a level A ring agent etc. are mentioned.

  When a material that contributes to curing is used as the liquid composition 142, the liquid composition 142 is cured at the time of connection, so that the conductive particles 132 are less likely to move in the width direction of the anisotropic conductive film 123 shown in FIG. Independence of the conductive particles 132 after connection is promoted. That is, it contributes to prevention of connection of the conductive particles 132. On the other hand, when a material that does not contribute to curing is used as the liquid composition 142, the fluidity in the thickness direction of the anisotropic conductive film 123 shown in FIG. It will be. For this reason, the movement to the surface (horizontal) direction (width direction of the anisotropic conductive film 123 shown in FIG. 3) of the electroconductive particle 132 is suppressed relatively. That is, regardless of whether or not the liquid composition 142 contributes to curing, it contributes to the improvement of the conduction performance of the connection structure.

  In addition, the liquid composition 142 exhibits the same effect as the bubbles 141 by being diffused by an external force when connected by lamination, stretching, or anisotropic conductive film 123. That is, the internal stress of the anisotropic conductive film 123 is relieved in the foam considered to be made of a liquid composition in the same manner as the above-described bubble 141. In other words, the bubbles are not limited to the bubbles 141, and include those generated from the liquid composition 142. In the case of the foam composed of the liquid composition 142, there is a high probability of contact with the conductive particles 132 due to the manufacturing process. However, since the bubbles made of the liquid composition 142 are liquid unlike the bubbles 141, it is assumed that the above-mentioned steep stress change is unlikely to occur. In this case, the contact state between the bubbles and the conductive particles 132 is not considered. There is no particular restriction.

  In addition, the site | part in which the liquid composition 142 is provided is not necessarily limited between the insulating adhesive 133 and the electroconductive particle 132 on account of the manufacturing method. For example, it may be provided at any location between the first insulating adhesive layer 130 and the conductive particles 132 or between the second insulating adhesive layer 131 and the conductive particles 132. Even when the liquid composition 142 is included in the bubbles 141 when the liquid composition 142 is provided, the same effects as described above can be obtained. This is because it is difficult to specify the position of the main part of the composition because the highly viscous resin occupies the mobility of the foam containing the liquid composition 142 relatively high.

[Manufacturing process of anisotropic conductive film]
Subsequently, the manufacturing method of the anisotropic conductive film 23 which concerns on one Embodiment of this invention is demonstrated. First, a mold for arranging conductive particles is prepared. As shown in FIG. 4, for example, a mold 50 in which openings 51 filled with conductive particles are regularly formed is used. The mold 50 is filled with the conductive particles 32 using a squeegee or the like. Thus, the conductive particles 32 are arranged on the surface of the mold 50 in a pattern corresponding to the pattern of the openings 51.

  In the mold 50, an interval a between the openings 51 is set to 3 to 6 μm, for example. As will be described later, the size of the bubbles 41 contained between the conductive particle-containing layer 34 and the first insulating adhesive layer 30 is controlled according to the interval a of the openings 51, and the interval is 3 1-5 μm depending on the opening 51 of ˜6 μm. As described above, the size of the bubbles 41 is such that bubbles having a size of 1 μm or more are diffused by an external force when laminated or stretched in the process of manufacturing the anisotropic conductive film 23 and the maximum length is less than 1 μm. It may become a fine bubble. Further, by adjusting the interval a and the shape of the openings 51 of the mold 50, the size of the bubbles 41, that is, the maximum length can be made 1 μm or less.

  Further, the mold 50 is formed with the openings 51 regularly arranged, the opening diameter of each opening 51 is slightly larger than the diameter of the conductive particles 32, and the depth is substantially the same as the diameter of the conductive particles 32. Has been. Thereby, the metal mold | die 50 can arrange the electroconductive particle 32 in a single layer regularly when the electroconductive particle 32 is filled.

  As shown in FIG. 5, in the mold 50, a photocurable adhesive layer 55 is laminated on the surface in which the opening 51 is filled with the conductive particles 32. The adhesive layer 55 is made of an organic resin binder mixed with a film-forming resin, a thermosetting resin, a curing agent, and other additives constituting the conductive particle-containing layer 34 described later, and is supported on the peeling substrate 56. Has been. As the peeling base material 56, a base material such as a polyethylene terephthalate film generally used in an anisotropic conductive film (ACF) can be used.

  The adhesive layer 55 is pressed from the peeling substrate 56 side by a heating and pressing head, laminated on one surface of the mold 50 where the opening 51 is formed, and pressed into the opening 51. Thereby, the adhesive layer 55 is formed with the concave / convex pattern 40 corresponding to the pattern of the opening 51, and the conductive particles 32 filled in the opening 51 are transferred to the convex portions 40 a of the concave / convex pattern 40.

  Next, the adhesive layer 55 is peeled from the mold 50 together with the peeling substrate 56. Thereby, as shown in FIG. 6, the uncured electroconductive particle content layer 34 supported by the peeling base material 56 is formed. In the conductive particle-containing layer 34, a concavo-convex pattern 40 is formed on the one surface 34 a opposite to the surface supported by the peeling substrate 56 according to the pattern of the openings 51.

  As for the uneven | corrugated pattern 40, the electroconductive particle 32 is fixed to the convex part 40a. As for the electroconductive particle 32, a part 32a is exposed outside from the upper surface of the convex part 40a. Further, the concave / convex pattern 40 has concave portions 40 b formed in accordance with the intervals of the openings 51.

  Next, the conductive particle-containing layer 34 is cured by being irradiated with ultraviolet rays from the side 34a on which the concave / convex pattern 40 is formed. Here, since the conductive particle-containing layer 34 is insufficiently irradiated with ultraviolet rays on the back side of the conductive particles 32 of the convex portion 40a, the conductive particle-containing layer 34 is lower than the conductive particles 32, that is, other than the conductive particles 32. The surface 34b side is uncured.

  Next, as shown in FIG. 7, the conductive particle-containing layer 34 is laminated on one surface 34 a with the first insulating adhesive layer 30 supported by the peeling substrate 35. At this time, since the conductive particle-containing layer 34 is cured by ultraviolet irradiation, when the first insulating adhesive layer 30 is laminated, the concave portions 40b of the concave / convex pattern 40 and the first insulating adhesive layer 30 are laminated. The bubble 41 can be included between the two. In addition, the conductive particle-containing layer 34 can bring the first insulating adhesive layer 30 into contact with a part 32 a of the conductive particle 32 exposed from the convex portion 40 a of the concavo-convex pattern 40.

  Note that the position of the bubbles 41 depends on the position of the convex portions 40 of the concave / convex pattern 40 of the mold 50, so that the bubbles 41 are arranged between the conductive particles 32. For this reason, although the bubble 41 is arrange | positioned near the electroconductive particle 32, it does not become the arrangement | positioning which touches the electroconductive particle 32 directly. Specifically, most of the bubbles 41 are located outside the conductive particles 32 through a distance of about 0.2 to 0.3 times the outer diameter of the conductive particles 32. This is considered to be due to contact and peeling with the insulating adhesive 33 included in the conductive particle-containing layer 34 at the end of the opening 51 of the mold 50. For this reason, the bubbles 41 are less likely to be adjacent to the conductive particles 32, and the number of bubbles 41 located in the vicinity of the conductive particles 32 is reduced. That is, the ratio of the bubbles 41 existing between the conductive particles 32 increases. However, if the liquid composition 142 shown in FIG. 3 described above includes a vacuole, the vacuole comes into contact with the conductive particles 132 due to the characteristics of the manufacturing method.

  Next, the conductive substrate-containing layer 34 is peeled off from the peeling base material 56, and the second insulating adhesive layer 31 supported by the peeling base material 36 is laminated on the exposed other surface 34 b. Thereby, as shown in FIG. 2, the anisotropic conductive film 23 is formed.

  In order to secure the independence of the conductive particles 132 and prevent the occurrence of a short circuit, when manufacturing the anisotropic conductive film 123 of another embodiment according to the present invention shown in FIG. The liquid composition 142 is applied or sprayed between at least one of the conductive layer 132 and the first insulating adhesive layer 130 or between the conductive particles 132 and the insulating adhesive 133 of the conductive particle-containing layer 134. To do. In the case where the liquid composition 142 is applied or sprayed between the conductive particles 132 and the first insulating adhesive layer 130, the conductive particles 132 are filled in the mold 50 (see FIG. 4), and then the insulating property is increased. Before laminating with the adhesive layer 130, a very small amount of the liquid composition 142 that does not reach the bottom surface of the mold 50 is applied or sprayed. Contact with the first insulating adhesive layer 130 and the insulating adhesive 133 at the end of the opening 51 of the mold 50 can be relaxed.

  Moreover, when the liquid composition 142 contributes to hardening, in order to promote the independence of the electroconductive particle 132 at the time of hardening, it contributes to the connection prevention of the electroconductive particle 132 at the time of connection. On the other hand, when the liquid composition 142 does not contribute to curing, it contributes to the pushing of the conductive particles 132 at the time of connection. Therefore, the fluidity in the thickness direction of the anisotropic conductive film 123 is promoted, and the surface (lateral) direction is increased. Is relatively restrained from moving. That is, regardless of whether or not the liquid composition 142 contributes to curing, it contributes to the improvement of the conduction performance of the connection structure.

[Connection process using anisotropic conductive film]
Subsequently, the connection process using the anisotropic conductive film 23 which concerns on one Embodiment of this invention is demonstrated. When the electronic component 18 is connected to the terminal portion 17a via the anisotropic conductive film 23, first, the peeling substrate 35 is peeled off, and the exposed first insulating adhesive layer 30 is removed from the terminal portion of the transparent electrode 17. The anisotropic conductive film 23 is placed on 17a and temporarily pressure-bonded from above the peeling substrate 36 by a temporary pressure-bonding means (not shown).

  Then, after peeling the peeling base material 36 and placing the electronic component 18 on the anisotropic conductive film 23, the electronic component 18 and the anisotropic conductive film 23 are put together with the anisotropic conductive film 23 by the heating press head 3 serving as a thermocompression bonding means. The heating and pressing head 3 generates heat while pressing toward the 17a side. The first and second insulating adhesive layers 30 and 31 show fluidity in the anisotropic conductive film 23 by the heat and pressure applied by the heating and pressing head 3, and the terminal portion 17 a of the transparent substrate 12 and the electronic component 18. It flows out from between the connection terminals 18a.

  Here, since the conductive particles 32 are exposed from the protrusions 40a and are in contact with the first insulating adhesive layer 30 in the conductive particle-containing layer 34, the first insulating adhesive layer 30 flows out. As a result, the conductive particles 32 come into contact with the terminal portions 17a. In addition, since the conductive particle-containing layer 34 is in an uncured state because the back side of the conductive particles 32 is not sufficiently irradiated with ultraviolet rays, the second insulating adhesive layer 31 is heated by the heat pressing head 3. The conductive particles 32 come into contact with the connection terminals 18a of the electronic component 18 by being discharged together.

  Therefore, as shown in FIG. 8, in the anisotropic conductive film 23, the conductive particles 32 are sandwiched between the terminal portions 17a of the transparent substrate 12 and the connection terminals 18a of the electronic component 18, and are thermally cured in this state. As a result, the electronic component 18 is electrically and mechanically connected to the terminal portion 17a via the anisotropic conductive film 23. Note that the electrical and mechanical connection between the terminal portion 17a of the transparent substrate 12 and the connection terminal 18a of the electronic component 18 is not limited to heating and pressing. That is, it may be cured and bonded by the combined use of heat pressing and light irradiation, or may be bonded only by light irradiation. In addition, there is no particular problem even if provisional pressure bonding or curing with light heat or light irradiation is used.

  At this time, the anisotropic conductive film 23 regularly contains bubbles 41 between the conductive particle-containing layer 34 and the first insulating adhesive layer 30 according to the arrangement of the recesses 40b. Even when an internal stress due to curing shrinkage occurs between the electronic component 18 and the terminal portion 17a, the warping of the transparent substrate 12 after connection can be reduced by the stress relaxation action of the bubbles 41. Therefore, even in the liquid crystal display panel 10 using the transparent substrate 12 that has been reduced in thickness, it is possible to suppress the occurrence of warping and thereby reduce color unevenness.

  In addition, the anisotropic conductive film 23 is a conventional anisotropic conductive film in which the conductive particles 32 are irregularly mixed because the conductive particles 32 are regularly arranged in a single layer according to the concavo-convex pattern 40. Compared to the above, unnecessary conductive particles not involved in the electrical connection between the electronic component 18 and the terminal portion 17a can be reduced as much as possible. Furthermore, stress relaxation occurs locally in the peripheral region of the conductive particles 32 due to the bubbles arranged in the vicinity of the conductive particles 32, but since the conductive particles 32 themselves are regularly arranged, Due to the regularity, the expression of the effect extends uniformly over the whole, and this can be controlled.

  Next, examples of the anisotropic conductive film according to one embodiment of the present invention will be described. In this example, a plurality of anisotropic conductive film samples (Examples 1 to 10) in which the bubble size and the curing system of the insulating adhesive layer were changed, and the anisotropic conductive film containing no bubbles were used. Samples (Comparative Examples 1 and 2) were prepared, and the amount of warpage and conduction resistance of the glass substrate when the IC chip was mounted on the glass substrate were measured.

  The samples of Examples and Comparative Examples are anisotropic conductive films in which conductive particle-containing layers are sandwiched between first and second insulating adhesive layers, and each conductive particle-containing layer is a first conductive film. A concavo-convex pattern is formed on one side in contact with the insulating adhesive layer, and conductive particles are regularly arranged in a single layer in the recess. However, in the sample according to each example, bubbles are included between the conductive particle-containing layer and the first insulating adhesive layer, and in the sample according to the comparative example, bubbles are not included.

[Creation of conductive particle-containing layer]
For the conductive particle-containing layer, an organic resin binder (solid content 50%) having the composition shown in Tables 1 and 2 below is applied to a PET film with a bar coater, dried in hot air at 70 ° C. for 5 minutes, and a thickness of 5 μm. An adhesive layer film was prepared.

  In addition, as shown in FIG. 9, the molds according to the example and the comparative example are regularly formed with openings having a hole diameter of 5 μm square and a hole depth of 3 μm, and the opening interval a is 3 μm (Example 1). And Example 6) Three types of 4 μm (Examples 2, 4, 5, 7, 9, 10, Comparative Examples 1 and 2) and 6 μm (Examples 3 and 8) were prepared. As the conductive particles filled in the openings of the respective molds, Au-203A (average particle diameter: 3 μm) manufactured by Sekisui Chemical Co., Ltd. was used and filled with a squeegee.

  And the adhesive layer film created previously was laminated | stacked with the laminator whose roll surface temperature is 45 degreeC to the metal mold | die with which electroconductive particle was filled, and it peeled from the metal mold | die after that. Thereby, while the uneven | corrugated pattern according to the opening pattern of a metal mold | die was formed in the adhesive layer film on one surface, the electroconductive particle was transferred by the convex part. The conductive particles are regularly arranged in a single layer, and a part of the conductive particles is exposed outward from the convex portion.

This adhesive layer film was irradiated with UV light having a wavelength of 365 nm and an integrated light amount of 4000 mJ / cm ² from one surface side where the uneven pattern was formed, to form a conductive particle-containing layer. The conductive particle-containing layer is UV-cured on one side where the uneven pattern is formed, but the back side of the conductive particles has a low UV irradiation amount and is in an uncured state.

[Creation of insulating adhesive layer]
For the insulating adhesive layer, an organic resin binder composed of the composition shown in Table 1 and Table 2 below is applied to a PET film with a bar coater and dried with hot air at 80 ° C. for 3 minutes to produce an adhesive layer film having a thickness of 5 μm did.

  Thereby, the 1st, 2nd insulating adhesive layer supported by PET film was created.

[Lamination process of conductive particle-containing layer and insulating adhesive layer]
Next, the conductive particle-containing layer and the insulating adhesive layer were laminated to prepare a sample of an anisotropic conductive film. First, the 1st insulating adhesive layer was laminated with the laminator whose roll surface temperature is 45 degreeC on the one surface side in which the uneven | corrugated pattern of the electroconductive particle content layer was formed.

  At this time, in Examples 1 to 5, bubbles were included in the concave portions of the concave / convex pattern. On the other hand, in Comparative Examples 1 and 2, lamination was performed so that bubbles were not mixed. In Examples 6 to 10, lamination was similarly performed so that fine bubbles of less than 1 μm were included.

  Next, the PET film was peeled from the other surface opposite to the one surface on which the uneven pattern of the conductive particle-containing layer was formed, and the second insulating adhesive layer was laminated with a laminator having a roll surface temperature of 45 ° C.

  Thereby, an anisotropic conductive film having a total thickness of 20 μm according to each example and comparative example was prepared.

[Characteristic evaluation]
As an evaluation element,
Outline: 1.8mm x 20mm
Thickness: 0.5mm
Au-plated bump outline; 30 μm × 85 μm
Au-plated bump height; 15 μm
IC for evaluation was used.

  An ITO coating glass having a glass thickness of 0.7 mm was used as an evaluation substrate to which the evaluation IC was connected.

  A connected body sample in which an IC for evaluation was connected to the ITO coated glass by heat and pressure through anisotropic conductive films (35 mm × 24 mm) according to Examples and Comparative Examples was formed. The mounting conditions according to each example and comparative example are as follows.

  In Examples 1 to 3, Examples 6 to 8 and Comparative Examples 1 and 2 (cationic curing system), the temperature is 180 ° C.-70 MPa-5 seconds, and the thickness is as a buffer material between the heating press head and the evaluation IC. 50 μm Teflon (registered trademark) was interposed.

  In Example 4 and Example 9 (anionic curing system), the temperature is 200 ° C.-70 MPa-5 seconds, and a Teflon (registered trademark) having a thickness of 50 μm is interposed as a cushioning material between the heating press head and the evaluation IC. It was.

  In Example 5 and Example 10 (radical curing system), the temperature is 160 ° C.-70 MPa-5 seconds, and a Teflon (registered trademark) having a thickness of 50 μm is interposed as a buffer material between the heat-pressing head and the evaluation IC. It was.

  About each connection body sample of the above Examples and Comparative Examples, the connection resistance when a current of 2 mA was passed by a four-terminal method using a digital multimeter was measured at the beginning of connection and after TCT (80 ° C., 85%, 250 H). did. Moreover, about each connection body sample, it scanned from the ITO coating glass lower surface of the evaluation base material using a stylus type surface roughness meter (CL-830: manufactured by Kosaka Laboratory Ltd.), and ITO before and after connection of the evaluation IC The amount of warpage (μm) of the coating glass was measured and the difference was determined. The measurement results are shown in Tables 1 and 2.

  As shown in Table 1, according to this example, since all the bubbles are included in the concave portions of the concave / convex pattern of the conductive particle-containing layer, the internal stress generated in the connection portion after connection of the evaluation IC is alleviated. We were able to. Therefore, the amount of warpage at the initial stage of connection and after TCT can be suppressed, and the conduction resistance after TCT can be suppressed to a maximum of 6.0Ω or less, and a good conduction resistance can be realized.

  On the other hand, in Comparative Example 1, since air bubbles were not included, the effect of relaxing the internal stress generated at the connection portion of the evaluation IC did not work, and the amount of warpage at the initial connection was as large as 15 μm. In Comparative Example 2, although a stress relaxation agent was added, the warping amount at the initial stage of connection was as large as 10 μm compared with Examples 1 to 5 in which bubbles were included, and the effect of reducing the warping was small. Further, in Comparative Example 2, by adding a stress relaxation agent, the cohesive force of the adhesive component was reduced, the connection reliability was lowered, and the conduction resistance after TCT was increased to 10Ω.

  In Example 4, the amount of warpage slightly decreased. This is probably because the curing system of Example 2 was changed from a cationic system to an anionic system, and the curing rate was slower than that of the cationic system. Further, in Example 5, when the curing system of Example 2 was changed from a cationic system to a radical system, the amount of warpage slightly increased although it was excellent in low-temperature rapid curability.

  Moreover, as shown in Table 2, according to Examples 6-10, all are the recessed part of the uneven | corrugated pattern of an electroconductive particle content layer, and a fine bubble between electroconductive particle and a 1st insulating adhesive layer. Therefore, the internal stress generated at the connection location after connection of the evaluation IC could be more relaxed than in Examples 1-5. In other words, it was found that the fine bubbles can reduce the amount of warp somewhat than the larger bubbles, and can relieve the internal stress generated at the connection location. This is presumed to be due to the fact that by making the bubbles fine bubbles, the effect of dispersing stress is further increased by the presence of a large number of bubbles that exert a relaxation effect on the internal stress.

  Similarly to Example 4, in Example 9, the amount of warpage slightly decreased in the same manner. This is probably because the curing system of Example 7 was changed from the cationic system to the anionic system, and the curing rate was slower than that of the cationic system. In Examples 5 and 10, when the curing system was changed from the cationic system of Examples 2 and 7 to the radical system, the amount of warpage slightly increased although it was excellent in low-temperature rapid curing.

DESCRIPTION OF SYMBOLS 1 Liquid crystal display device, 3 Heating press head, 10 Liquid crystal display panel, 11, 12 Transparent substrate, 12a Edge, 16, 17 Transparent electrode, 17a Terminal part, 18 Electronic component, 18a Connection terminal, 20 COG mounting part, 23, 123 anisotropic conductive film, 30, 130 first insulating adhesive layer, 31, 131 second insulating adhesive layer, 32, 132 conductive particles, 33, 133 insulating adhesive, 34, 134 conductive Conductive particle-containing layer, 34a, 134a One side, 34b, 134b Other side, 35, 36, 135, 136 Peeling substrate, 40, 140 Concave and convex pattern, 40a, 140a Convex part, 40b, 140b Concave part, 41, 141 Air bubble, 50 Mold, 51 opening, 55 adhesive layer, 56 release substrate, 142 liquid composition

Claims (17)

A first insulating adhesive layer;
A conductive particle-containing layer containing conductive particles contained in an insulating adhesive;
Air bubbles are contained between the conductive particle-containing layer and the first insulating adhesive layer,
An anisotropic conductive film in which the conductive particles are regularly arranged and the bubbles are regularly included.   The anisotropic conductive film according to claim 1, wherein the bubbles are included according to the regularity of the conductive particles.   The anisotropic particle according to claim 1, wherein the conductive particle-containing layer has the conductive particles arranged in a single layer and regularly, and the bubbles are present in an intermediate region between the adjacent conductive particles. Conductive film. Furthermore, it has a second insulating resin layer,
The anisotropic conductive film according to claim 1, wherein the conductive particles are sandwiched between the first insulating adhesive layer and the second insulating adhesive layer.   The anisotropic conductive film according to any one of 1 to 4, wherein the conductive particle-containing layer has a part of the conductive particles exposed at an interface with the first insulating adhesive layer.   The anisotropic conductive film according to any one of claims 1 to 5, wherein the curing system of the first insulating adhesive layer is any one of a cationic curing system, an anion curing system, and a radical curing system.   The anisotropic conductive film according to claim 1, wherein the size of the bubbles is less than 5 μm.   The anisotropic conductive film according to any one of claims 1 to 7, wherein the conductive particle-containing layer is thicker at a portion containing the conductive particles than a thickness between the conductive particles.   The anisotropic conductive film according to claim 8, wherein the bubbles are included in recesses formed between the conductive particles.   The anisotropic conductive film of any one of Claims 1-9 by which a liquid composition is provided in the site | part between the said 1st insulating adhesive layer and the said electroconductive particle.   The anisotropic conductive film according to claim 10, wherein the liquid composition is contained in the bubbles. Conductive particles are arranged in the opening of the mold having an opening, and the adhesive layer of the adhesive film supported by the release substrate is laminated on the surface on which the conductive particles of the mold are arranged. ,
Pressing the adhesive layer onto the mold from the top surface of the release substrate, pressing the adhesive layer into the opening,
The adhesive film is peeled off from the mold, and the conductive particles are regularly exposed on the surface of the adhesive layer so that the conductive particles are partially exposed from the surface and adhered, and an uneven shape corresponding to the mold is molded. Forming a particle-containing layer,
A first insulating adhesive layer is laminated on the surface of the conductive particle-containing layer, and bubbles are regularly contained between the conductive particle-containing layer and the first insulating adhesive layer. A method for producing an anisotropic conductive film.   The manufacturing method of the anisotropic conductive film of Claim 12 which laminates the said 1st insulating adhesive layer after hardening the surface in which the uneven | corrugated shape of the said electroconductive particle content layer was formed.   The method for producing an anisotropic conductive film according to claim 12 or 13, wherein a second insulating adhesive layer is laminated on the back surface opposite to the front surface of the conductive particle-containing layer.   The connection body by which the terminal of the 1st electronic component and the terminal of the 2nd electronic component were anisotropically conductive-connected using the anisotropic conductive film of any one of Claims 1-11. The manufacture of the connection body by which the terminal of the 1st electronic component and the terminal of the 2nd electronic component were anisotropically conductive-connected using the anisotropic conductive film of any one of Claims 1-11. In the method
The manufacturing method of the connection body which joins the said 1st electronic component and the said 2nd electronic component by the heat press or light irradiation through the said anisotropic conductive film. Using the anisotropic conductive film according to any one of claims 1 to 11, in a connection method for anisotropic conductive connection between a terminal of a first electronic component and a terminal of a second electronic component,
A connection method in which the first electronic component and the second electronic component are joined by heat pressing or light irradiation via the anisotropic conductive film.

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