JP6654954B2 - Anisotropic conductive connection structure - Google Patents

Description

  The present invention relates to an anisotropic conductive connection structure.

  For example, as disclosed in Patent Documents 1 to 3, a touch panel is widely used as an input device for performing an input operation on an image displayed on a display. The touch panel is divided into an input operation area where an input operation is performed by a user and a peripheral area of the input operation area. An electrode group in which a plurality of electrodes are wired in a predetermined wiring pattern is arranged in the input operation area. Then, a plurality of electrode terminals are extracted from the electrode group. The electrode terminals are arranged in the peripheral area. Further, the electrode terminals are connected to terminals of the electronic component. Specifically, the electrode terminals and the terminals of the electronic component are anisotropically conductively connected by sandwiching conductive particles contained in the anisotropic conductive adhesive.

  In such a touch panel, when the user touches any position on the touch panel, an electrical change (for example, a change in capacitance) occurs in the electrode group at that position. Then, position information on the position where the electrical change has occurred is input to the electronic circuit via the electrode group and the electrode terminal. The electronic circuit recognizes the position touched by the user based on the input position information.

JP 2006-344163 A JP 2012-203696 A JP 2015-34279 A

  By the way, since the input operation area is an area visually recognized by the user, the electrode group is required to have transparency. ITO is known as an electrode material having such transparency. However, ITO has a problem that the resistance value is very high. For this reason, ITO is often applied to a small touch panel that is relatively unaffected by the height of the resistance value.

  As a technique for solving the above problem, Patent Literatures 2 and 3 disclose a technique in which an electrode group is configured by metal nanowires and a binder. Since metal nanowires have a very low resistance value compared to ITO, they can also be applied to large touch panels. For this reason, metal nanowires have received a great deal of attention as a material for forming an electrode group of a touch panel.

  By the way, since the electrode terminals of the touch panel are arranged in a peripheral area that is hardly seen by the user, transparency is not always required. However, from the viewpoint of manufacturing cost and the like, in recent years, the number of cases where the electrode group and the electrode terminal are formed of the same electrode material has been increasing. Therefore, when the electrode group is composed of the metal nanowires and the binder, the electrode terminals are also composed of the metal nanowires and the binder.

  However, metal nanowires are very brittle materials. Therefore, when the anisotropic conductive adhesive is directly disposed on the electrode terminal including the metal nanowire, the conductive particles break the metal nanowire of the electrode terminal at the time of anisotropic conductive connection. That is, the conductive particles break the electrode terminals. As a result, conduction between the conductive particles and the electrode terminals becomes insufficient, and the resistance value of the anisotropic conductive connection portion becomes extremely large. For this reason, when the electrode terminal including the metal nanowires and the electrode terminal of the electronic component are directly anisotropically conductively connected, a product that can withstand practical use could not be manufactured. That is, the electrode terminal including the metal nanowire and the electrode terminal of the electronic component could not be directly anisotropically conductively connected.

  For this reason, conventionally, after laminating a metal film or a metal paste on the electrode terminal, the electrode terminal and the terminal of the electrode component are anisotropically conductively connected. However, this method has a problem that the cost for the anisotropic conductive connection becomes extremely large.

  In addition, ITO is a material having higher strength than metal nanowires and an aggregate (electrode terminal) formed by the metal nanowires. Therefore, when the electrode terminals are made of ITO, the electrode terminals are not easily broken by the conductive particles. However, as described above, there is a problem that ITO has a very high resistance value. Therefore, even if the electrode terminals are made of ITO, the above problem cannot be fundamentally solved.

  Further, electrode terminals including metal nanowires are expected to be used for various applications other than touch panels in the future. Accordingly, there has been a strong demand for a technique for stably and anisotropically connecting such an electrode terminal to another electrode terminal at low cost.

  Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to directly and anisotropically connect a first electrode terminal including a metal nanowire and a second electrode terminal. It is an object of the present invention to provide a new and improved anisotropic conductive connection structure.

  According to an aspect of the present invention, there is provided an electronic component including a substrate, a first electrode terminal formed on the substrate and including a metal nanowire, an electronic component including a second electrode terminal, Anisotropic conductive adhesive layer containing conductive particles that conduct between the electrode terminal and the second electrode terminal, the conductive particles cover the surface of the core particles containing the resin, the core particles, And a conductive coating layer, wherein a part of the lower end surface of the conductive particles is electrically connected to the first electrode terminal.

Here, the lower end surface of the conductive particles, a central area in contact with the substrate to break the first electrode terminal, are formed around the central region, the conductive region electrically connected to the first electrode terminal, the including.

  When the inter-terminal space of the first electrode terminal is less than 50 μm, the particle size of the conductive particles before anisotropic conductive connection is less than 5 μm, and the inter-terminal space of the first electrode terminal is 50 μm to 100 μm. If it is less than 5 μm, the particle size of the conductive particles before the anisotropic conductive connection is 5 μm or more and less than 10 μm, and if the space between the terminals of the first electrode terminal is 100 μm or more, the anisotropic conductive connection of the conductive particles The previous particle size may be 10 μm or more and less than the width of the first electrode terminal.

  The compression recovery rate of the conductive particles may be 10% or less.

  Further, the conductivity of the coating layer may be equal to or higher than the conductivity of gold.

  According to another aspect of the present invention, there is provided a touch panel including the above-described anisotropic conductive connection structure.

  According to another aspect of the present invention, there is provided an image display device including the above touch panel.

  As described above, according to the present invention, a part of the lower end surface of the conductive particles is electrically connected to the first electrode terminal, so that the first electrode terminal and the second electrode terminal are directly connected by anisotropic conductive connection. can do.

It is a top view showing an example of an electrode group and an electrode terminal concerning an embodiment of the present invention. It is a side sectional view showing the example of composition of the anisotropic conductive connection structure concerning the embodiment. FIG. 4 is a plan view illustrating a positional relationship between a central region and a peripheral region. It is a sectional side view for explaining the problem which the conventional anisotropic conductive adhesive has. It is a sectional side view for explaining the problem which the conventional anisotropic conductive adhesive has. It is a top view which shows typically the surface state of the electrode terminal containing a metal nanowire. It is a top view which shows typically the mode (surface state) in which the electrode terminal containing the metal nanowire was broken.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the specification and the drawings, components having substantially the same functional configuration are denoted by the same reference numerals, and redundant description is omitted.

<1. Overview of electrode group and electrode terminal>
In the present embodiment, the first electrode terminal 30 shown in FIG. 1 and a second electrode terminal 52 described later are anisotropically conductively connected. Here, the first electrode terminal 30 and the second electrode terminal 52 are some of the components of the touch panel. That is, the present embodiment is applied to a touch panel. The touch panel is provided on a display surface of various displays (image display devices), for example. Therefore, first, the first electrode terminal 30 and its peripheral structure will be described with reference to FIG. In the present embodiment, the electrode group 20 and the first electrode terminals 30 are wired on the substrate 15. The substrate 15 is divided into an input operation area A where an input operation is performed by a user and a peripheral area B around the input operation area A. The electrode group 20 is arranged in the input operation area A, and the first electrode terminals 30 are arranged in the peripheral area B. The electrode group 20 includes a plurality of electrodes 20a wired in a predetermined wiring pattern. This wiring pattern may be a lattice pattern or the like in addition to the parallel pattern shown in FIG. Then, the plurality of first electrode terminals 30 are drawn out of the electrode group 20. The width W of the first electrode terminal 30 is larger than the width of the electrode 20a. The first electrode terminals 30 extend in directions parallel to each other. The width W and the inter-terminal space P of the first electrode terminal 30 may be set appropriately according to the characteristics required for the touch panel. In the present embodiment, the first electrode terminal 30 and the second electrode terminal 52 of the electronic component 50 described later are anisotropically conductively connected. Of course, the wiring pattern of the electrode group 20 is not limited to the example of FIG.

  The substrate 15 is made of a material having transparency. Here, the material constituting the substrate 15 is not particularly limited as long as it has transparency. For example, the substrate 15 may be made of a material used as a substrate of a touch panel. Examples of the material forming the substrate 15 include transparent resins such as polycarbonate, acrylic, polyethylene terephthalate, and triacetyl cellulose. The substrate 15 may be made of a transparent glass or the like. However, the substrate 15 is preferably made of a transparent resin. In this case, the first electrode terminal 30 may be less likely to be broken during anisotropic conductive connection.

  Further, the substrate may be provided with an optical adhesive layer such as OCA (Optically Clear Adhesive) or a layer made of OCR (Optically Clear Resin). In the case where such a layer is provided, if the pressure is excessively large, a defect in appearance is likely to occur. Therefore, the thickness of such a layer is preferably 100 μm or less as an example.

  The electrode group 20 and the first electrode terminal 30 include a metal nanowire and a binder. That is, in the present embodiment, a conductive network is formed by the metal nanowires. The type of metal constituting the metal nanowire is not particularly limited, and any metal nanowire used for a conventional electrode can be suitably applied to the present embodiment. Examples of the metal constituting the metal nanowire include Ag, Au, Ni, Cu, Pd, Pt, Rh, Ir, Ru, Os, Fe, Co, and Sn. The metal nanowire may be composed of any one or more of these metals. For example, the metal nanowire may be composed of Ag. Further, the metal nanowires may be subjected to a treatment (for example, a dyeing or blackening treatment) for lowering the haze value (that is, lowering the visibility).

  The size of the metal nanowire is not particularly limited. For example, the dimensions of the metal nanowires may be comparable to the dimensions of metal nanowires used in conventional electrodes. For example, the average diameter of the metal nanowires may be 1-500 nm. When the average diameter of the metal nanowire is 1 nm or less, the conductivity of the metal nanowire may be deteriorated. If the average diameter of the metal nanowires is larger than 500 nm, the total light transmittance of the electrode group 20 may deteriorate, and the haze may increase. Here, the average diameter of the metal nanowires is, for example, an arithmetic average of the diameters of a plurality of metal nanowires. The shape of the metal nanowire can be measured by observing the metal nanowire with an SEM (scanning electron microscope) or the like.

  Further, the average length of the metal nanowires may be set according to the pitch, the size between the first electrode terminals 30, the space between the terminals, and the like. For example, when the pitch between the first electrode terminals 30 is 20 μm or more, the average length of the metal nanowires is 1.5 times or less, preferably 1.2 times or less the pitch between the first electrode terminals 30, It is more preferably at most 1 times, further preferably at most 0.5 times. The average length of the metal nanowire is preferably 5 to 50 μm. When the pitch between the first electrode terminals 30 is less than 20 μm, the average length of the metal nanowires may be 5 μm or more and 0.5 times or less the pitch between the first electrode terminals 30. preferable. When the above condition is satisfied, the visibility of the metal nanowire can be reduced (that is, difficult to see), and the occurrence of a short circuit between the first electrode terminals 30 can be suppressed. Further, a good conductive network can be formed by the metal nanowire.

  The type of the binder is not particularly limited, and any binder may be used as long as it is applied to an electrode using metal nanowires. The binder is made of, for example, a cured product of a photocurable resin. Examples of the photocurable resin include resins disclosed in Patent Documents 2 and 3. As an example, the binder may be a (meth) acryloyl compound or the like. Further, the binder may include a resin other than the photocurable resin (for example, an amide compound disclosed in Patent Document 2). In addition, an additive that can be added to the electrode using the metal nanowires may be added to the binder. In addition, the content of the metal nanowire may be appropriately adjusted according to the characteristics and the like required for the electrode group 20 and the first electrode terminal 30.

  Further, the thicknesses of the electrode group 20 and the first electrode terminal 30 are not particularly limited. However, these thicknesses may be adjusted according to the average diameter and the content of the metal nanowires. As a rough guide, the thickness is preferably not less than the average diameter of the metal nanowire and not more than 500 nm. However, it is preferable that the thickness of the electrode group 20 and the first electrode terminal 30 be as thin as possible within the above range. Thereby, the conductive network can be made denser.

<2. Configuration of anisotropic conductive connection structure>
Next, a configuration of the anisotropic conductive connection structure (hereinafter, also simply referred to as “connection structure”) 10 according to the present embodiment will be described with reference to FIGS. 2, the connection structure 10 includes a substrate 15, a first electrode terminal 30, an anisotropic conductive adhesive layer (hereinafter, also simply referred to as an "adhesive layer") 40, and an electronic component 50. And The electronic component 50 includes an electronic component main body 51 and a second electrode terminal 52.

  The adhesive layer 40 is obtained by curing an anisotropic conductive adhesive, and includes a cured resin layer 41 and conductive particles 42. Here, in the present embodiment, the adhesive layer 40 is provided directly on the first electrode terminal 30. That is, in the present embodiment, the first electrode terminal 30 and the second electrode terminal 52 are directly anisotropically conductively connected. The anisotropic conductive adhesive includes a curable resin and conductive particles 42. The curable resin contains a polymerizable compound and a curing initiator.

  The polymerizable compound is a resin that is cured by a curing initiator. The cured polymerizable compound, that is, the cured resin layer 41 adheres the first electrode terminal 30 and the second electrode terminal 52 in the adhesive layer 40 and holds the conductive particles 42 in the adhesive layer 40. I do. Examples of the polymerizable compound include an epoxy polymerizable compound and an acrylic polymerizable compound. The epoxy polymerizable compound is a monomer, oligomer, or prepolymer having one or more epoxy groups in a molecule. Examples of the epoxy polymerizable compound include various bisphenol type epoxy resins (bisphenol A type, F type, etc.), novolak type epoxy resin, various modified epoxy resins such as rubber and urethane, naphthalene type epoxy resin, biphenyl type epoxy resin, phenol novolak type Epoxy resins, stilbene-type epoxy resins, triphenolmethane-type epoxy resins, dicyclopentadiene-type epoxy resins, triphenylmethane-type epoxy resins, and prepolymers thereof are exemplified.

  The acrylic polymerizable compound is a monomer, oligomer, or prepolymer having one or more acrylic groups in a molecule. Examples of the acrylic polymerizable compound include methyl acrylate, ethyl acrylate, isopropyl acrylate, isobutyl acrylate, epoxy acrylate, ethylene glycol diacrylate, diethylene glycol diacrylate, trimethylolpropane triacrylate, dimethylol tricyclodecane diacrylate, and tetramethylene glycol. Tetraacrylate, 2-hydroxy-1,3-diacryloxypropane, 2,2-bis [4- (acryloxymethoxy) phenyl] propane, 2,2-bis [4- (acryloxyethoxy) phenyl] propane, Dicyclopentenyl acrylate, tricyclodecanyl acrylate, tris (acryloxyethyl) isocyanate, urethane acrylate and the like. That. In the present embodiment, any one of the above-listed polymerizable compounds may be used, or two or more thereof may be used in any combination.

  The curing initiator is, for example, a thermosetting initiator. The thermosetting initiator is a material that is cured together with the polymerizable compound by heat. The type of the thermosetting initiator is not particularly limited. Examples of the thermal curing initiator include a thermal anion or thermal cationic curing initiator for curing an epoxy polymerizable compound, and a thermal radical polymerization type curing agent for curing an acrylic polymerizable compound. In this embodiment, an appropriate thermosetting initiator may be selected depending on the polymerizable compound. In addition, as another example of the curing initiator, a photo-curing initiator may be mentioned. Examples of the photocuring initiator include a photoanion or photocationic curing initiator for curing an epoxy polymerizable compound, a photoradical polymerization type curing agent for curing an acrylic polymerizable compound, and the like. In this embodiment, an appropriate photocuring initiator may be selected depending on the polymerizable compound.

  The curable resin is preferably an epoxy-based curable resin. That is, the curable resin used in the present embodiment preferably contains an epoxy-based polymerizable compound. This is because the epoxy-based cured resin layer 41 is more excellent in shape retention after curing than the acrylic-based cured resin layer 41, so that the connection between opposing electronic components is stabilized. That is, in the present embodiment, when the conductive particles 42 are unlikely to repel, if the distance between the first electrode terminal 30 and the second electrode terminal 52 increases, the conductive particles 42 are separated from the second electrode terminal 52. Could be done. In this case, the connection resistance between the conductive particles 42 and the second electrode terminals 52 becomes extremely large.

  In addition, the anisotropic conductive adhesive may contain a film-forming resin, various additives, and the like in addition to the above components. The film-forming resin is added to the anisotropic conductive adhesive when it is desired to form the film into a film in order to make the anisotropic conductive adhesive easy to handle. As the film-forming resin, for example, 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 can be used. In the present embodiment, only one of these film-forming resins can be used, or two or more of them can be used in any combination. The film-forming resin is preferably a phenoxy resin from the viewpoint of improving film-forming properties and adhesion reliability. When the anisotropic conductive adhesive has a film shape, the thickness of the film (that is, the anisotropic conductive film) is not particularly limited. However, if the film is too thick, the amount of unnecessary resin becomes too large, and there is a problem in fluidity and the like. Therefore, it is preferably 100 μm or less, more preferably 40 μm or less. If it is too thin, it becomes difficult to handle, so it is preferably at least 5 μm, more preferably at least 12 μm.

  Examples of additives that can be added to the anisotropic conductive adhesive include a silane coupling agent, an inorganic filler, a coloring agent, an antioxidant, and a rust inhibitor. The type of the silane coupling agent is not particularly limited. Examples of the silane coupling agent include epoxy-based, amino-based, mercapto sulfide-based, and ureide-based silane coupling agents. When these silane coupling agents are added to the anisotropic conductive adhesive, the adhesiveness to an inorganic substrate such as a glass substrate can be improved.

  Further, the inorganic filler is an additive for adjusting the fluidity and the film strength of the anisotropic conductive adhesive, particularly the minimum melt viscosity described later. The type of the inorganic filler is not particularly limited. Examples of the inorganic filler include silica, talc, titanium oxide, calcium carbonate, and magnesium oxide.

The conductive particles 42 are a material for anisotropically conductively connecting the first electrode terminal 30 and the second electrode terminal 52 in the adhesive layer 40. Specifically, the conductive particles 42 sandwiched between the first electrode terminal 30 and the second electrode terminal 52 in the adhesive layer 40 connect the first electrode terminal 30 and the second electrode terminal 52 to each other. Make it conductive. On the other hand, the other conductive particles 42 (for example, the conductive particles 42 that have entered the gap between the first electrode terminals 30 and the conductive particles 42 that have entered the gap between the second electrode terminals 52, etc.) No electrical connection is made between the terminals (that is, a short circuit in which the conductive particles 42 are connected between the first electrode terminals 30 and a short circuit in which the conductive particles 42 are connected between the second electrode terminals 52 are not generated). .
Therefore, the conductive particles 42 maintain the insulating property between the first electrode terminals 30 and between the second electrode terminals 52 in the adhesive layer 40 while maintaining the insulating property between the first electrode terminals 30 and the second electrode terminals 52. Can be conducted. That is, the conductive particles 42 conduct between the first electrode terminal 30 and the second electrode terminal 52 by being held between the first electrode terminal 30 and the second electrode terminal 52 in the adhesive layer 40, thereby making anisotropic conductive connection. The conductive particles 42 may be dispersed to such an extent that they do not cause a short circuit, or may be individually arranged in the anisotropic conductive film. This arrangement is appropriately set according to the size of each electrode terminal, the distance in the arrangement direction of the electrode terminals, and the like, but may be regular.

  Here, the conductive particles 42 break the first electrode terminal 30 and are electrically connected to a part of the first electrode terminal 30. Specifically, as shown in FIGS. 2 and 3, the lower end surface (the surface facing the substrate 15) of the conductive particles 42 has a central region 43 where the first electrode terminal 30 is broken, A conductive region formed around the conductive region and electrically connected to the first electrode terminal; Therefore, the conductive particles 42 are in conduction with the first electrode terminal 30 in the conduction region 44. On the other hand, the central region 43 is in contact with, for example, the substrate 15.

  FIG. 6 is a plan view schematically illustrating a surface state of the first electrode terminal 30 where conduction by the conductive particles 42 is not performed. According to FIG. 6, it can be seen that the metal nanowires 31 are dispersed in the first electrode terminals 30 and that they form a conductive network. FIG. 7 is a plan view illustrating a surface state of the first electrode terminal 30 broken by the conductive particles 42. A region 32 in FIG. 7 indicates a region broken by the conductive particles 42. The surface state in FIG. 7 can be confirmed by the following steps. That is, the repair process is performed after the first electrode terminal 30 and the second electrode terminal 52 are anisotropically conductively connected. Here, the repair processing means that the electronic component 50 is peeled off from the substrate 15. Next, the surface of the first electrode terminal 30 is observed by SEM.

  The conductive particles 42 include a core particle 42a and a coating layer 42b that covers the core particle 42a. The core particles 42a are preferably particles made of a plastic material having excellent compression deformation. Examples of the material constituting the core particles 42a include (meth) acrylate-based resin, polystyrene-based resin, styrene- (meth) acrylic copolymer resin, urethane-based resin, epoxy-based resin, phenolic resin, and acrylonitrile-styrene (AS) Resins, benzoguanamine resins, divinylbenzene resins, styrene resins, polyester resins, and the like. For example, when the core particles 42a are formed of a (meth) acrylate resin, the (meth) acrylic resin has a (meth) acrylic acid ester and, if necessary, a reactive double bond copolymerizable therewith. It is preferred that the copolymer is a copolymer of a compound having the compound and a bifunctional or polyfunctional monomer.

  The coating layer 42b is made of a conductive material. Examples of the material forming the coating layer 42b include silver, gold, nickel, copper, and palladium. The coating layer 42b may be composed of any one or more of these. A projection may be formed on the coating layer 42b. The projection is made of, for example, the same material as the coating layer 42b. The length of the projection is not particularly limited, but may be 10 to 500 nm or 10% or less of the particle diameter of the conductive particles 42. The particle size of the conductive particles 42, the presence or absence of protrusions, and the length can be confirmed by observing the conductive particles 42 with, for example, an SEM.

  Further, the particle size of the conductive particles 42 is not particularly limited, but is preferably 1/80 or more, more preferably 1/20 or more of the width of the first electrode terminal 30, and 1/10 to 1/10. / 5 is even more preferred.

  The electronic component 50 includes the electronic component main body 51 and the second electrode terminal 52 as described above. The type of the electronic component body 51 is not particularly limited. For example, the electronic component body 51 may be a flexible substrate. A flexible substrate is a substrate formed of a material having high flexibility and flexibility. The material forming the flexible substrate is not particularly limited, and a material applied to a known flexible substrate is also applicable to the present embodiment. Examples of the material forming the flexible substrate include a resin such as polyethylene terephthalate, polyethylene naphthalate, polyethersulfone, polyethylene, polycarbonate, polyimide, and acrylic resin, and a thin metal or glass.

  A plurality of second electrode terminals 52 are provided on the electronic component body 51. The second electrode terminals 52 are parallel to each other. The width and the space between the terminals of the second electrode terminals 52 may be the same as those of the first electrode terminals 30. Each of the second electrode terminals 52 is anisotropically conductively connected to the first electrode terminal 30. The material forming the second electrode terminal 52 is not particularly limited. Examples of the material forming the second electrode terminal 52 include metals such as aluminum, silver, nickel, copper, and gold, indium tin oxide (ITO), indium zinc oxide (IZO), indium oxide, and conductive tin oxide. , Antimony tin oxide (ATO), and conductive metal oxides such as conductive zinc oxide, and conductive polymers such as polyaniline, polypyrrole, and polythiophene. The metal constituting the second electrode terminal 52 may be plated with various metals (for example, gold, tin, and the like). The second electrode terminal 52 may be made of the same electrode material as the first electrode terminal 30.

<3. Preferred Conditions for Adhesive Layer>
Particularly preferred conditions for the adhesive layer are as follows.
(Condition 1) When the curable resin is an acrylic curable resin, the adhesive layer 40 preferably has a minimum melt viscosity of 8000 to 12000 Pa · s. In this case, the viscosity of the acrylic curable resin decreases, so that the acrylic curable resin easily flows. Therefore, a load is easily transmitted to the conductive particles 42 at the time of thermocompression bonding between the first electrode terminal 30 and the second electrode terminal 52. That is, the conductive particles 42 are easily crushed. As a result, the surface area of the conductive particles 42 increases, and the contact area with the metal nanowires increases. Therefore, the connection resistance decreases. Note that when the curable resin is an epoxy-based curable resin, this requirement does not necessarily have to be satisfied. This is because the epoxy-based curable resin is more excellent in shape retention after curing than the acrylic-based cured resin, so that the connection between opposing electronic components is stabilized.

  (Condition 2) The glass transition point of the curable resin is preferably as high as possible, for example, preferably 150 ° C. or higher. In this case, since the cured resin layer 41 can firmly hold the conductive particles 42, repulsion of the conductive particles 42 can be suppressed for a long period of time. As a result, for example, the connection resistance after a reliability evaluation test described below decreases.

(Condition 3)
When the inter-terminal space of the first electrode terminal 30 is less than 50 μm, it is preferable that the particle size of the conductive particles 42 before anisotropic conductive connection (that is, the diameter at the time of a sphere) is less than 5 μm. When the inter-terminal space of the first electrode terminal 30 is 50 μm or more and less than 100 μm, the particle diameter of the conductive particles 42 before the anisotropic conductive connection is preferably 5 μm or more and less than 10 μm. When the inter-terminal space of the first electrode terminal 30 is 100 μm or more, it is preferable that the particle size of the conductive particles 42 before the anisotropic conductive connection is 10 μm or more and less than the width of the first electrode terminal. In this case, a short circuit between the first electrode terminals 30 or between the second electrode terminals 52 can be suppressed, so that the first electrode terminals 30 and the second electrode terminals 52 can be more stably anisotropically. Conductive connection can be made. The particle size of the conductive particles 42 can be confirmed by, for example, SEM.

(Condition 4)
It is preferable that the material constituting the covering layer 42b has as high a conductivity as possible. Of the materials listed above, gold is preferred, and silver is more preferred. That is, the conductivity of the coating layer 42b is preferably equal to or higher than the conductivity of gold. This is because the higher the conductivity of the coating layer 42b, the better the conductivity with the first electrode terminal 30.

(Condition 5)
The coating layer 42b is preferably formed with protrusions. In this case, the projections increase the contact area between the coating layer 42b and the first electrode terminals 30.

(Condition 6)
The compression recovery rate of the conductive particles 42 is preferably 10% or less. In this case, since the conductive particles 42 are easily compressed and deformed, the contact area with the first electrode terminal 30 (that is, the area of the peripheral region 44) is increased, and the first electrode terminal 30 is not easily broken. Become. Further, the repulsion of the conductive particles 42 is less likely to occur. Here, the compression recovery rate is measured by, for example, the following method. First, a load (reversal load value) is applied at a temperature of 25 ° C. toward the center of the conductive particles 42 until the conductive particles 42 are compressed and deformed by 30%, that is, until the diameter is reduced by 30%. Thereafter, unloading is performed up to the load value for the origin (0.40 mN). The load-compression displacement during this time is measured, and the compression recovery rate can be obtained from the following equation. The load speed is 0.33 mN / sec.
Compression recovery rate (%) = [(L1−L2) / L1] × 100
L1: Compressive displacement from load value for origin to reverse load value when load is applied L2: Unload displacement from reverse load value to load value for origin when release load is released The displacement of the particles 42 can be measured by an SEM or the like.

  When at least one of the above conditions 1 to 6 is satisfied, the first electrode terminal 30 and the second electrode terminal 52 can be stably anisotropically conductively connected. Specifically, the connection resistance between the conductive particles 42 and the first electrode terminals 30 decreases. Further, since the conductive particles 42 are in direct contact with the first electrode terminals 30, the connection structure 10 can be manufactured at low cost.

<4. About the effect of particle repulsion>
As described above, one of the factors that increases the connection resistance between the conductive particles 42 and the first electrode terminals 30 is the repulsion of the conductive particles 42. Therefore, the repulsion of the conductive particles 42 will be described with reference to FIGS.

  FIG. 4 shows a state immediately after the first electrode terminal 30 and the second electrode terminal 52 are anisotropically conductively connected with an anisotropic conductive adhesive that does not satisfy any of the above-mentioned conditions 1 to 7. In FIG. 4, the first electrode terminal 30 and the second electrode terminal 52 are anisotropically conductively connected by the adhesive layer 140. The adhesive layer 140 includes a cured resin layer 141 and conductive particles 142. As shown in FIG. 4, immediately after the anisotropic conductive connection, the conductivity between the conductive particles 142 and the first electrode terminal 30 is maintained. However, thereafter, as shown in FIG. 5, the conductive particles 142 repel. That is, the conductive particles 142 try to return to the original shape. The repulsion of the conductive particles 42 occurs due to, for example, deterioration of the cured resin layer 41 or the like. As a result, the conductive particles 142 and the first electrode terminal 30 are separated. If the two are separated from each other, their connection resistances will increase significantly.

  In the conventional anisotropic conductive adhesive, the repulsion of the conductive particles 142 was rather preferable in some cases. That is, when the first electrode terminal 30 is made of a strong material such as ITO, even if the conductive particles 142 are repelled, at least both can be kept in contact with each other. On the other hand, when the cured resin layer 141 deteriorates, the distance between the first electrode terminal 30 and the second electrode terminal 52 increases. However, if the conductive particles 142 are repelled, the conductive particles 142 can conduct between the first electrode terminal 30 and the second electrode terminal 52.

  However, in the present embodiment, it can be said that repulsion of the conductive particles 42 is rather undesirable. Therefore, it can be said that the present embodiment has been made based on completely new knowledge that was not present in the conventional anisotropic conductive adhesive. Incidentally, in the present embodiment, since the conductive particles 42 are unlikely to repel, if the distance between the first electrode terminal 30 and the second electrode terminal 52 is increased, the conductive particles 42 are separated from the second electrode terminal 52. It may be separated. For this reason, as described above, the curable resin is preferably an epoxy-based curable resin that is hardly deteriorated.

<5. Manufacturing method of connection structure>
The method for manufacturing the connection structure 10 is not particularly limited. That is, the connection structure 10 can be manufactured by a normal pressure bonding method using an anisotropic conductive adhesive. That is, the substrate 15 on which the first electrode terminals 30 are formed, the anisotropic conductive adhesive, and the electronic component 50 are sequentially laminated. Here, the electronic component 50 is aligned so that the positions of the first electrode terminal 30 and the second electrode terminal 52 are aligned. Next, a heat tool is pressed onto the electronic component 50 via a cushioning material or the like. Next, the first electrode terminal 30 and the second electrode terminal 52 are thermocompression bonded using a heat tool. Through the above steps, the connection structure 10 is manufactured.

<1. Example 1>
(1-1. Preparation of First Electrode Terminal)
According to the method disclosed in Example 1 of Patent Document 3, a plurality of first electrode terminals 30 were formed on a substrate 15 made of polyethylene terephthalate. Here, the inter-terminal space P and the width W of the first electrode terminal 30 were both 400 μm. That is, L / S = 1/1. The thickness of the first electrode terminal 30 was 300 nm. The metal nanowires constituting the first electrode terminals 30 were silver nanowires, and the average length of the silver nanowires was adjusted to 500 nm or less.

(1-2. Preparation of flexible substrate)
A flexible substrate (electronic component body 51) was produced by applying a Ni / Au plating having a thickness of 18 μm to a polyimide substrate having a thickness of 25 μm (SC18-25-00CE manufactured by Nippon Steel Chemical Co., Ltd.). Next, a plurality of second electrode terminals 52 made of Cu were arranged on the flexible substrate. Here, the inter-terminal space of the second electrode terminal 52 was 400 μm, and the thickness was 18 μm. L / S was set to 1/1.

(1-3. Preparation of anisotropic conductive film)
30 parts by mass of phenoxy resin (product name: YP50, manufactured by Nippon Steel Chemical Co., Ltd.), 20 parts by mass of polybutadiene powder (product name: XER-91, manufactured by JSR), 10 parts by mass of filler (product name: R202, manufactured by Nippon Aerosil Co., Ltd.), epoxy An adhesive composition was prepared by mixing 40 parts by mass of a compound (product name: Novacure (registered trademark) HXA3932HP, manufactured by Asahi Kasei E-materials Co., Ltd.) and conductive particles (manufactured by Nippon Chemical Co., Ltd.). Here, the compounding amount of the conductive particles was adjusted such that the number density in the anisotropic conductive film was 3000 to 7000 particles / mm ² . That is, although the number density varied in each in-plane region of the anisotropic conductive film, the number density was adjusted so that the number density in each region was in the range of 3000 to 7000 / mm ² . The same applies to other examples and comparative examples below. Then, an adhesive composition was applied to a 38-μm-thick release-treated PET film by a bar coater and dried to obtain an 18-μm-thick anisotropic conductive film. Therefore, the curable resin of Example 1 is an epoxy curable resin.

  Here, the glass transition point of the anisotropic conductive film, that is, the curable resin was 130 ° C., and the minimum melt viscosity was 13000 Pa · s. The glass transition point was measured by a tensile test measuring device (RHEOVIBRON manufactured by A & D), and the minimum melt viscosity was measured by the following steps. First, a laminated sheet having a thickness of 300 μm was prepared by laminating anisotropic conductive films. Next, the laminated sheet was set on a melt viscometer (manufactured by Thermo Fisher Scientific). Then, by driving the melt viscometer under the conditions of a heating rate of 10 ° C./min, a frequency of 1 Hz, a pressure of 1 N, and a measurement temperature range of 30 to 180 ° C., the lowest melt viscosity of the anisotropic conductive film, that is, the curability The minimum melt viscosity of the resin was measured.

  The particle diameter of the conductive particles 42 before the anisotropic conductive connection was 5 μm, and the coating layer 42b was gold. The coating layer 42b had no protrusion, and the compression recovery was 10%. The compression recovery rate was measured with a micro compression tester manufactured by Shimadzu Corporation.

(1-4. Production of Connection Structure)
The substrate 15 on which the first electrode terminals 30 were formed, the anisotropic conductive film, and the electronic component 50 were sequentially laminated. Here, the electronic component 50 was aligned so that the positions of the first electrode terminal 30 and the second electrode terminal 52 were aligned. Next, a heat tool was pressed onto the electronic component 50 via a cushioning material or the like. Next, the first electrode terminal 30 and the second electrode terminal 52 were thermocompression bonded using a heat tool. Through the above steps, the connection structure 10 was manufactured. Here, the condition of the thermocompression bonding was 160 ° C.-4 MPa-5 sec. That is, the first electrode terminal 30 and the second electrode terminal 52 are thermocompressed for 5 seconds at a pressure of 4 MPa while the temperature of the heat tool is raised so that the temperature of the heat tool becomes 160 ° C. in 5 seconds from the start of the crimping. did. Therefore, the first embodiment satisfies the conditions 4 and 6 described above.

(1-5. Evaluation of initial connection resistance)
The connection resistance of the connection structure 10 was measured using a digital multimeter (trade name: Digital Multimeter 7561, manufactured by Yokogawa Electric Corporation). When the connection resistance was less than 100Ω, the evaluation was “A”. When the connection resistance was 100Ω or more and less than 300Ω, the evaluation was “B”. When the connection resistance was 300Ω or more, the evaluation was “C”.

(1-6. Evaluation of connection resistance after reliability test)
A reliability test was performed by leaving the connection structure 10 in an environment at a temperature of 60 ° C. and a relative humidity of 95% for 100 hours. Then, 1-5. The connection resistance of the connection structure 10 was measured in the same manner as described above. When the connection resistance was less than 300Ω, the evaluation was “A”. When the connection resistance was 300Ω or more and less than 1000Ω, the evaluation was “B”. When the connection resistance was 1000Ω or more, the evaluation was “C”.

(1-7. Evaluation of peel strength)
The peel strength of the connection structure 10 was measured before and after the reliability evaluation test. The peel strength before the reliability evaluation test is the initial peel strength. The peel strength was measured using a tensile tester (trade name: Tensilon, manufactured by A & D Corporation). Specifically, the connection structure 10 was cut into a width of 1 cm. Next, the cut connection structure 10 was placed horizontally. Next, a tensile test was performed on the connection structure 10 at an angle of 90 degrees. At this time, the peel strength, that is, the adhesive strength was measured. When the adhesive strength was 10 N / cm or more, the evaluation was “A”, and when it was less than 10 N / cm, the evaluation was “B”.

<2. Example 2>
The same processing as in Example 1 was performed, except that the conductive particles 42 were changed to conductive particles (manufactured by Nippon Chemical Co., Ltd.) having a compression recovery rate of 30%. The particle size of the conductive particles 42 before the anisotropic conductive connection was 5 μm, and the coating layer 42b was gold. Also, there were no protrusions on the coating layer 42b. In the second embodiment, Condition 4 described above is satisfied.

<3. Example 3>
The same processing as in Example 1 was performed, except that the conductive particles 42 were changed to conductive particles (manufactured by Nippon Chemical Co., Ltd.) having a compression recovery rate of 30%. The particle size of the conductive particles 42 before the anisotropic conductive connection was 5 μm, and the coating layer 42b was nickel. In addition, there were protrusions on the coating layer 42b. When the length of the protrusion was measured for the plurality of conductive particles 42, the length of the protrusion was in the range of 0.05 to 0.3 μm. In addition, the length of the protrusion of the conductive particle 42 was measured by the following steps. That is, 50 conductive particles 42 not contributing to the connection were arbitrarily selected. Then, the length of the projections of each conductive particle 42 was measured by observing each conductive particle 42 from the substrate 15 side by SEM (scanning electron microscope). The particle size of the conductive particles 42 was 5 μm. In addition, the particle size of the conductive particles 42 was set to a size excluding the size of the protrusion. The same applies to the following embodiments. The projections are formed by the same metal particles as the coating layer 42b. Projections were formed in a region of 80% or more of the total surface area of the conductive particles. Therefore, the projections covered almost the entire surface of the conductive particles. In the third embodiment, Condition 5 described above is satisfied.

<4. Example 4>
The conductive particles 42 were changed to conductive particles having a compression recovery rate of 30% (manufactured by Nippon Chemical Co., Ltd.), and the number density in the anisotropic conductive film was adjusted to 100 to 1000 particles / mm ^2. The same processing as in Example 1 was performed except that the thickness of the anisotropic conductive film was changed to 23 μm. The particle size of the conductive particles 42 before the anisotropic conductive connection was 20 μm, and the coating layer 42b was nickel. In addition, there were protrusions on the coating layer 42b. When the length of the protrusion was measured by the same process as in Example 3, it was in the range of 0.05 to 0.3 μm. Further, the projections were formed in an area of 80% or more of the total surface area of the conductive particles. In the fourth embodiment, the above conditions 3 and 5 are satisfied.

<5. Example 5>
The conductive particles 42 were changed to conductive particles having a compression recovery rate of 30% (manufactured by Nippon Chemical Co., Ltd.), and the number density in the anisotropic conductive film was adjusted to 100 to 1000 particles / mm ^2. The same processing as in Example 1 was performed except that the thickness of the anisotropic conductive film was changed to 23 μm. The particle size of the conductive particles 42 before the anisotropic conductive connection was 20 μm, and the coating layer 42b was silver. In addition, there were protrusions on the coating layer 42b. When the length of the protrusion was measured by the same process as in Example 3, it was in the range of 0.05 to 0.3 μm. Further, the projections were formed in an area of 80% or more of the total surface area of the conductive particles. In the fifth embodiment, the above-described conditions 3, 4, and 5 are satisfied.

<6. Example 6>
The conductive particles 42 were changed to conductive particles having a compression recovery rate of 30% (manufactured by Nippon Chemical Co., Ltd.), and the number density in the anisotropic conductive film was adjusted to 100 to 1000 particles / mm ^2. The same processing as in Example 1 was performed except that the thickness of the anisotropic conductive film was changed to 23 μm. The particle size of the conductive particles 42 before the anisotropic conductive connection was 20 μm, and the coating layer 42b was gold. In addition, there were protrusions on the coating layer 42b. When the length of the protrusion was measured by the same process as in Example 3, it was in the range of 0.05 to 0.3 μm. Further, the projections were formed in an area of 80% or more of the total surface area of the conductive particles. Therefore, in the sixth embodiment, the above-described conditions 3, 4, and 5 are satisfied.

<7. Example 7>
The conductive particles 42 were changed to conductive particles (manufactured by Nippon Chemical Co., Ltd.) having a compression recovery rate of 10%, and the number density in the anisotropic conductive film was adjusted to 100 to 1000 / mm ^2. The same processing as in Example 1 was performed except that the thickness of the anisotropic conductive film was changed to 23 μm. The particle size of the conductive particles 42 before the anisotropic conductive connection was 20 μm, and the coating layer 42b was gold. In addition, there were protrusions on the coating layer 42b. When the length of the protrusion was measured by the same process as in Example 3, it was in the range of 0.05 to 0.3 μm. Further, the projections were formed in an area of 80% or more of the total surface area of the conductive particles. Therefore, in the seventh embodiment, the above-described conditions 3, 4, 5, and 6 are satisfied.

<8. Example 8>
20 parts by mass of phenoxy resin (product name: FX-280S, manufactured by Nippon Steel Chemical Co., Ltd.), 10 parts by mass of phenoxy resin (product name: YP50, manufactured by Nippon Steel Chemical Co., Ltd.), polybutadiene powder (product name: XER-91, manufactured by JSR) 20 parts by mass, 10 parts by mass of filler (product name: R202, manufactured by Nippon Aerosil Co., Ltd.), 40 parts by mass of epoxy compound (product name: Novacure (registered trademark) HXA3932HP, manufactured by Asahi Kasei E-materials Co., Ltd.), and conductive particles 42 of Example 7 Was mixed to prepare an adhesive composition. In addition, the number density of the conductive particles 42 was adjusted to be 100 to 1000 particles / mm ² . Then, the adhesive composition was applied to a 38-μm-thick release-treated PET film by a bar coater and dried to obtain a 23-μm-thick anisotropic conductive film. Therefore, the curable resin of Example 8 is an epoxy-based curable resin. Other processes were performed in the same manner as in Example 1.

  Here, the glass transition point of the anisotropic conductive film, that is, the curable resin was 150 ° C., and the minimum melt viscosity was 15000 Pa · s. Therefore, in the eighth embodiment, the above-described conditions 2, 3, 4, 5, and 6 are satisfied.

<9. Example 9>
60 parts by mass of phenoxy resin (product name: YP50, manufactured by Nippon Steel Chemical Co., Ltd.), 30 parts by mass of polybutadiene powder (product name: XER-91, manufactured by JSR), 10 parts by mass of acrylic compound (product name: DCP, manufactured by Shin-Nakamura Chemical Co., Ltd.) An adhesive composition was prepared by mixing 2 parts by weight of a polymerization initiator (product name: Niiper BW, manufactured by NOF CORPORATION) and the conductive particles of Example 7. In addition, the number density of the conductive particles 42 was adjusted to be 100 to 1000 particles / mm ² . Then, the adhesive composition was applied to a 38-μm-thick release-treated PET film by a bar coater and dried to obtain a 23-μm-thick anisotropic conductive film. Therefore, the curable resin of Example 9 is an acrylic curable resin. Other processes were performed in the same manner as in Example 1.

  Here, the glass transition point of the anisotropic conductive film, ie, the curable resin, was 100 ° C., and the minimum melt viscosity was 10,000 Pa · s. Therefore, in the ninth embodiment, the above-described conditions 1, 3, 4, 5, and 6 are satisfied.

<10. Example 10>
The same processing as in Example 9 was performed except that the conductive particles 42 were changed to conductive particles (manufactured by Nippon Chemical Co., Ltd.) having a compression recovery rate of 10%. The particle size of the conductive particles 42 before the anisotropic conductive connection was 20 μm, and the coating layer 42b was gold. Also, there were no protrusions on the coating layer 42b. Therefore, in the tenth embodiment, the above-described conditions 1, 3, 4, and 6 are satisfied.

<11. Comparative Example 1>
The same processing as in Example 1 was performed, except that the conductive particles 42 were changed to conductive particles (manufactured by Nippon Chemical Co., Ltd.) having a compression recovery rate of 30%. The particle size of the conductive particles before the anisotropic conductive connection was 5 μm, and the coating layer was nickel. There were no protrusions on the coating layer. Therefore, Comparative Example 1 does not satisfy any of the above conditions.

<12. Comparative Example 2>
The same processing as in Comparative Example 1 was performed except that the conditions of the thermocompression bonding were set to 160 ° C., 4 MPa, and 5 seconds. Therefore, Comparative Example 2 does not satisfy any of the above-described conditions, but the conditions of thermocompression bonding are different from Comparative Example 1.

<13. Comparative Example 3>
10 parts by mass of phenoxy resin (product name: FX-280S, manufactured by Nippon Steel Chemical Co., Ltd.), 30 parts by mass of phenoxy resin (product name: YP50, manufactured by Nippon Steel Chemical Co., Ltd.), polybutadiene powder (product name: XER-91, manufactured by JSR) 30 parts by mass, 20 parts by mass of filler (product name: R202, manufactured by Nippon Aerosil Co., Ltd.), 10 parts by mass of acrylic compound (product name: DCP, manufactured by Shin-Nakamura Chemical Co., Ltd.), polymerization initiator (product name: Niiper BW, manufactured by NOF CORPORATION) By mixing 2 parts by mass of the conductive particles 42 of Comparative Example 1, an adhesive composition was prepared. The number density of the conductive particles 42 was the same as in Example 1. Then, an adhesive composition was applied to a 38-μm-thick release-treated PET film by a bar coater and dried to obtain an 18-μm-thick anisotropic conductive film. Therefore, the curable resin of Comparative Example 3 is an acrylic curable resin. Other processes were performed in the same manner as in Comparative Example 1.

  Here, the glass transition point of the anisotropic conductive film, that is, the curable resin was 110 ° C., and the minimum melt viscosity was 13000 Pa · s. Therefore, Comparative Example 3 does not satisfy any of the above-described conditions.

<14. Comparative Example 4>
The same processing as in Example 1 was performed except that the conductive particles 42 were changed to conductive particles (manufactured by Nippon Chemical Co., Ltd.) having a compression recovery rate of 100%. The particle diameter of the conductive particles before the anisotropic conductive connection was 5 μm. The conductive particles were so-called metal spheres, and the material was nickel. In addition, there were no protrusions on the conductive particles. Therefore, Comparative Example 4 does not satisfy any of the above conditions.

  Table 1 collectively shows the configurations and evaluation results of Examples 1 to 10 and Comparative Examples 1 to 4 described above. An underline in Table 1 indicates a parameter that satisfies any of the conditions 1 to 6. “60/95” indicates “after the reliability evaluation test”.

<15. Evaluation>
In Examples 1 to 10 satisfying any one or more of the conditions 1 to 6, the initial characteristics and the characteristics after the reliability evaluation test were all good. Therefore, in the connection structure 10 according to Examples 1 to 10, the first electrode terminal 30 and the second electrode terminal 52 can be stably anisotropically conductively connected. That is, in Examples 1 to 10, the conductive particles 42 are less likely to repel, and the conductive particles 42 and the first electrode terminals 30 are stably conducted.

  Specifically, in Examples 1, 7 to 10, since the compression recovery rate of the conductive particles 42 is low, it is difficult to repel. In Examples 2, 5 to 10, since the coating layer 42b is made of silver or gold, the conductivity between the conductive particles 42 and the first electrode terminals 30 is high. In Examples 3 to 9, since the protrusion is formed on the coating layer 42b, the contact area between the conductive particles 42 and the first electrode terminal 30 increases. In Examples 4 to 10, since the particle size of the conductive particles 42 is large, the anisotropic conductive connection is stabilized. In Example 8, since the glass transition point of the curable resin is large, the conductive particles 42 can be held more firmly. In Examples 9 and 10, since the minimum melt viscosity of the acrylic curable resin is 8000 to 12000 Pa · s, the acrylic curable resin easily flows. Therefore, a load is easily transmitted to the conductive particles 42 at the time of thermocompression bonding between the first electrode terminal 30 and the second electrode terminal 52. Comparative Example 1 does not satisfy any of the above-described conditions, and thus has a low connection resistance. In Comparative Example 1, it is considered that the repulsion of the conductive particles occurred, and the conductivity between the conductive particles and the first electrode terminal 30 became extremely low. In Comparative Example 2, since the thermocompression bonding was performed at a higher pressure than in Comparative Example 1, although the initial connection resistance was good to some extent, the connection resistance after the reliability evaluation test increased significantly. Comparative Example 3 also had the same results as Comparative Example 1. Comparative Example 4 is an example in which a metal sphere was used as the conductive particles. In Comparative Example 4, as in Comparative Example 2, although the initial connection resistance was somewhat good, the connection resistance after the reliability evaluation test increased significantly. Therefore, in Comparative Examples 1 to 4, the first electrode terminal 30 and the second electrode terminal 52 are not substantially anisotropically conductively connected.

  As described above, the preferred embodiments of the present invention have been described in detail with reference to the accompanying drawings, but the present invention is not limited to such examples. It is obvious that those skilled in the art to which the present invention pertains can conceive various changes or modifications within the scope of the technical idea described in the claims. It is understood that these also belong to the technical scope of the present invention.

  For example, in the above embodiment, the connection structure 10 is applied to the touch panel, but the present invention is not limited to such an example. That is, the connection structure 10 can be applied without particular limitation as long as it is an anisotropic conductive connection between an electrode terminal using a metal nanowire and another electrode terminal. For example, it may be used for functional devices in the medical and bio fields, and may be used for batteries, energy-related devices, and in-vehicle (car) -related devices.

Reference Signs List 10 anisotropic conductive connection structure 15 substrate 20 electrode group 30 first electrode terminal 40 anisotropic conductive adhesive layer 41 cured resin layer 42 conductive particles 42a resin core 42b coating layer 50 electronic component 51 electronic component main body 52 2 electrode terminals

Claims (9)

Board and
A first electrode terminal formed on the substrate and including a metal nanowire;
An electronic component including a second electrode terminal;
An anisotropic conductive adhesive layer containing conductive particles for electrically connecting the first electrode terminal and the second electrode terminal,
The conductive particles, core particles containing a resin, and covering the surface of the core particles, and comprising a coating layer having conductivity,
A part of the lower end surface of the conductive particles is electrically connected to the first electrode terminal ,
The lower end surface of the conductive particles includes a central region that breaks the first electrode terminal and comes into contact with the substrate, and a conduction region that is formed around the central region and conducts with the first electrode terminal. , Anisotropic conductive connection structure. The anisotropic conductive connection structure according to claim 1, wherein the substrate is provided with an OCA (Optically Clear Adhesive) layer or an OCR (Optically Clear Resin) layer. When the inter-terminal space of the first electrode terminal is less than 50 μm, the particle size of the conductive particles before anisotropic conductive connection is less than 5 μm,
When the inter-terminal space of the first electrode terminal is 50 μm or more and less than 100 μm, the particle size of the conductive particles before anisotropic conductive connection is 5 μm or more and less than 10 μm,
2. When the inter-terminal space of the first electrode terminal is 100 μm or more, the particle diameter of the conductive particles before anisotropic conductive connection is 10 μm or more and less than the width of the first electrode terminal. 3. The anisotropic conductive connection structure according to 2.   The anisotropic conductive connection structure according to any one of claims 1 to 3, wherein a compression recovery rate of the conductive particles is 10% or less.   The anisotropic conductive connection structure according to claim 1, wherein the conductivity of the coating layer is equal to or higher than the conductivity of gold. The anisotropic conductive connection structure according to any one of claims 1 to 5, wherein the substrate is made of a transparent resin or transparent glass. The anisotropic conductive connection according to any one of claims 1 to 6, wherein the central region on the lower end surface of the conductive particle breaks the metal nanowire included in the first electrode terminal and comes into contact with the substrate. Structure. Comprising an anisotropic conductive connection structure according to any one of claim 1 to 7 touch panel. An image display device comprising the touch panel according to claim 8 .

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