JP2015191823A - Anisotropically conductive film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To arrange a photo-curable anisotropically conductive film in a monolayer form, and to increase the curing rate of portions of such a film in contact with center portions of wiring lines and connection terminals on a transparent substrate in a plane direction thereof, thereby reducing the resistance against conduction.SOLUTION: An anisotropically conductive film comprises: a binder composition including a photocurable compound and a photocuring agent; and conductive particles dispersed therein. In the anisotropically conductive film, each conductive particle has a surface at least partially covered with a light-diffusing filler. The total light reflectance of the anisotropically conductive film according to JIS K7375 is 25% or larger.

Description

  The present invention relates to an anisotropic conductive film useful when an electronic component such as an IC chip is mounted on a transparent substrate such as a glass substrate.

  Conventionally, an anisotropic conductive film in which conductive particles are dispersed in a photocurable binder composition is disposed between an electronic component such as an FPC or an IC chip and a transparent substrate on which wiring and connection terminals are formed. However, anisotropically conductive connection between the electronic component and the transparent substrate is performed by irradiating ultraviolet rays from the transparent substrate side and photocuring the anisotropic conductive film while pressing.

  When such an anisotropic conductive connection is performed, the anisotropic conductive film in the portion in contact with the wiring of the transparent substrate and the connection terminal is shielded from ultraviolet rays by the wiring and the connection terminal. There has been a problem that the curing rate at the center in the width direction is relatively lowered, and the conduction resistance between the transparent substrate and the electronic component is increased.

  Therefore, the anisotropic conductive film is constituted by laminating a photocurable conductive particle-containing layer and a photocurable insulating resin layer, and further, light scattering fine particles are formed on at least one of these layers. It is proposed to contain (Patent Document 1). According to this anisotropic conductive film, the light-scattering fine particles scatter ultraviolet rays also in the plane direction (edge direction) of the film, and irradiate the anisotropic conductive film in a portion in contact with the wiring or connection terminal of the transparent substrate. It can be expected that the amount of ultraviolet rays to be increased is increased and the curing rate of the part is increased.

International publication 2013/073563

  However, since the photocurable anisotropic conductive film of Patent Document 1 has a two-layer structure, there is a problem that the manufacturing cost increases. Moreover, there is a problem that the curing rate of the anisotropic conductive film in contact with the central portion of the transparent substrate wiring and terminals in the planar direction does not increase as expected and exceeds the intended conduction resistance value.

  An object of the present invention is to solve the problems of the prior art, a single layer of a photo-curing anisotropic conductive film, and in contact with the central portion in the planar direction of wiring and connection terminals of a transparent substrate. It is to provide an anisotropic conductive film capable of improving the curing rate of a part and reducing conduction resistance.

  The present inventor has inferred that when a light diffusable filler is blended into a single layered anisotropic conductive film, the curing rate can be improved by making it unevenly distributed rather than being dispersed throughout the film. Below, when at least a part of the surface of the conductive particles is coated with a light diffusing filler so that the total light reflectance of the anisotropic conductive film according to JIS K7375 is 25% or more, the above-mentioned object can be achieved. The headline and the present invention have been completed.

  That is, the present invention is an anisotropic conductive film comprising a binder composition containing a photocurable compound and a photocuring agent, and conductive particles dispersed therein, and at least the surface of the conductive particles. Provided is an anisotropic conductive film that is partially coated with a light diffusing filler and has a total light reflectance of 25% or more according to JIS K7375.

  Moreover, this invention provides the connection body by which the connection terminal of the transparent substrate and the electrode of the electronic component are anisotropically conductive-connected through the above-mentioned anisotropic conductive film.

  Furthermore, the present invention is a method for producing this connection body, wherein an anisotropic conductive film is disposed on a connection terminal of a transparent substrate, and an electrode of an electronic component is connected to the transparent substrate via the anisotropic conductive film. Provided is a manufacturing method for joining a transparent substrate and an electronic component by aligning with a terminal and pressing from the electronic component side and then irradiating ultraviolet rays from the transparent substrate side.

  In the photocurable anisotropic conductive film of the present invention, at least a part of the surface of the conductive particles is coated with a light diffusing filler, and the total light reflectance according to JIS K7375 is 25% or more. For this reason, when creating a connection body by anisotropically connecting the connection terminal of the transparent substrate and the electrode of the electronic component through this anisotropic conductive film, a part of the ultraviolet rays irradiated from the transparent substrate side is The light diffusing filler diffuses in the plane direction of the film inside the film without being emitted outside the anisotropic conductive film. As a result, the ultraviolet rays can be propagated to a portion of the transparent substrate wiring or connection terminal that is in contact with the central portion in the width direction, that is, a portion where the ultraviolet rays are difficult to reach, thereby improving the curing rate of the portion and reducing the conduction resistance. Can be made.

FIG. 1 is an explanatory diagram when light is irradiated from the transparent substrate side when a transparent substrate and an electronic component are bonded via an anisotropic conductive film.

<Anisotropic conductive film>
The anisotropic conductive film of the present invention is composed of a binder composition containing a photocurable compound and a photocuring agent, and conductive particles dispersed therein, and the characteristics thereof are as conductive particles. The surface is coated with a light-diffusing filler (light-diffusing filler-coated conductive particles), and the total light reflectance according to JIS K7375 of the anisotropic conductive film is 25% or more. That is.

(Light diffusing filler coated conductive particles)
The light diffusing filler-coated conductive particles are literally those in which at least a part of the surface of the conductive particles is coated with the light diffusing filler.

"Conductive particles"
As the conductive particles, conductive particles that have been conventionally applied to anisotropic conductive films can be employed. For example, particles of metal such as nickel, silver, gold and palladium; particles of alloy such as solder; particles of resin (resin core particles) such as styrene-divinylbenzene copolymer, benzoguanamine resin, cross-linked polystyrene resin and acrylic resin Examples thereof include metal-coated resin particles whose surfaces are coated with a metal thin film such as a nickel thin film or a nickel / gold thin film by an electroless plating method, a sputtering method, or the like. These conductive particles can be insulated with a thin resin film as required.

  The average particle size of such conductive particles varies depending on the wiring pitch of the transparent substrate to which the anisotropic conductive film is applied, the bump diameter of the electronic component, etc., but is usually 2 μm or more and 15 μm or less, preferably 2 μm or more and 10 μm or less, more Preferably they are 2 micrometers or more and 5 micrometers or less. The average particle size of the conductive particles can be measured with a general particle size distribution measuring device (for example, FPAR-1000, manufactured by Otsuka Electronics Co., Ltd.).

  In addition, the content of the conductive particles in the anisotropic conductive film is preferably 5% by mass or more from the viewpoint of preventing occurrence of short-circuits in anisotropic conductive connection, reducing conduction resistance, ensuring conduction reliability, and the like. It is 50 mass% or less, More preferably, it is 5 mass% or more and 30 mass% or less.

"Light diffusing filler"
The light diffusing filler is capable of diffusing ultraviolet rays incident on the anisotropic conductive film as a result in the plane direction (edge direction) of the anisotropic conductive film. Here, the diffusion means that the ultraviolet rays reflected or transmitted by the filler surface are refracted and emitted. As the light diffusing filler, inorganic fine particles and organic fine particles can be used, and can be appropriately selected according to the purpose of use of the anisotropic conductive film. Examples of the inorganic fine particles include aluminum oxide fine particles, magnesium oxide fine particles, titanium oxide fine particles, zinc oxide fine particles, and silica fine particles. As the organic fine particles, resin fine particles having a refractive index larger than that of the cured product of the photocurable resin constituting the anisotropic conductive film can be used.

  The average particle diameter of the light diffusing filler is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 50 nm or more and 800 nm or less from the viewpoint of facilitating the penetration of irradiation light to the non-transmissive region on the wiring. More preferably, it is 100 nm or more and 500 nm or less. Further, assuming that the average particle diameter of the light diffusing filler is in the above-mentioned range, from the viewpoint of stable anisotropic connection, the average particle diameter of the conductive particles is preferably 0.4 to 40, more preferably 0.5 to 40, and even more preferably 6 to 25. The average particle size of the light diffusing filler is preferably set to a size close to ½ of the wavelength of the irradiation light used for anisotropic conductive connection. The average particle size of the light diffusing filler can be measured by a general particle size distribution measuring device (for example, FPAR-1000, manufactured by Otsuka Electronics Co., Ltd.).

  The coverage ratio of the surface of the conductive particles by the diffusive filler as described above (the ratio of the area covered with the light diffusing filler of the light diffusing filler coated conductive particles to the total surface area of the conductive particles) is the effect of the invention. In order to fully realize, it is at least 15% or more, preferably 30% or more. This coverage can be measured with an electron microscope (SEM) and can usually be defined as the average value of 50 samples.

  Moreover, the light diffusable filler may be disperse | distributed independently in an anisotropic conductive film as an aspect which does not coat | cover the electrically-conductive particle. In this case, from the viewpoint of reliability after connection, the ratio of the light diffusing filler not coated with the conductive particles to the total light diffusing filler in the anisotropic conductive film is preferably 4% by mass or more and 15% by mass or less. More preferably, it is 6 mass% or more and 12 mass% or less.

(Curable compound)
There is no restriction | limiting in particular as a photocurable compound which comprises a binder composition, According to the intended purpose of an anisotropic conductive film, it can select suitably, For example, a photocationic curable compound, a photoradical curable compound, etc. Is mentioned.

  As the photocationic curable compound, those obtained by photocationic polymerization of a photocationic polymerizable compound (monomer or oligomer) used in known anisotropic conductive films can be used. Examples thereof include bisphenol A type epoxy compounds, bisphenol F type epoxy compounds, novolac type epoxy compounds, oxetane compounds, alicyclic epoxy compounds, and acrylic, urethane, or carboxylic acid modified epoxy compounds. These may be used individually by 1 type and may use 2 or more types together.

  As the photoradical curable compound, a radically polymerized photoradical polymerizable compound (monomer or oligomer) used in a known anisotropic conductive film can be used. Examples of such photo-radically polymerizable monomers include monofunctional (meth) acrylates such as methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, isobutyl (meth) acrylate, and ethylene glycol di (meth) acrylate. , Diethylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, dimethylol tricyclodecane di (meth) acrylate, tetramethylene glycol tetra (meth) acrylate, 2-hydroxy-1,3-di (meth) acryl Roxypropane, 2,2-bis [4-((meth) acryloxymethoxy) phenyl] propane, 2,2-bis [4-((meth) acryloxyethoxy) phenyl] propane, dicyclopentenyl (meth) acrylate The Examples include polyfunctional (meth) acrylates such as licyclodecanyl (meth) acrylate and tris ((meth) acryloxyethyl) isocyanurate, epoxy (meth) acrylate, urethane (meth) acrylate, and (meth) acrylate oligomers. These may be used individually by 1 type and may use 2 or more types together. Here, the term “(meth) acrylate” is a term including acrylate and methacrylate.

  The content of the photocurable compound in the anisotropic conductive film is preferably 5% by mass or more and 50% by mass or less, more preferably 5% by mass or more and 30% by mass, from the viewpoint of retention and stability after the conductive particles are pressed. It is as follows.

(Photocuring agent)
There is no restriction | limiting in particular as a photocuring agent, According to the objective, it can select suitably, It is possible to use the well-known photocationic curing agent or photoradical curing agent which generate | occur | produces an active cation seed | species or active radical seed | species from an ultraviolet-ray. it can. Examples of the photo cation curing agent include sulfonium salts and onium salts. Examples of the photo radical curing agent include alkylphenone photopolymerization initiators, acylphosphine oxide photopolymerization initiators, and titanocene photopolymerization. Examples thereof include initiators and oxime ester photopolymerization initiators.

  The content of the photocuring agent in the anisotropic conductive film is preferably 3 parts by mass with respect to 100 parts by mass of the photocationically polymerizable compound in the case of the photocationic curing agent from the viewpoint of the curing rate and the curing rate. The amount is 15 parts by mass or less, more preferably 5 parts by mass or more and 10 parts by mass or less. Moreover, in the case of a radical photocuring agent, it is preferably 3 parts by mass or more and 15 parts by mass or less, more preferably 5 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the photoradical polymerizable compound.

(Other ingredients)
The binder composition can contain a film-forming resin, a silane coupling agent, a solvent, and the like as long as they do not impair the effects of the invention. Examples of the film-forming resin include phenoxy resin, unsaturated polyester resin, saturated polyester resin, urethane resin, butadiene resin, polyimide resin, polyamide resin, polyolefin resin, and the like, and preferably 50 with respect to 100 parts by mass of the photocurable compound. More than 100 parts by mass and more preferably 60 parts by mass to 90 parts by mass. Examples of the silane coupling agent include an epoxy silane coupling agent, an acrylic silane coupling agent, a thiol silane coupling agent, an amine silane coupling agent, and the like. The total amount is 100 parts by mass, preferably 2 parts by mass or more and 25 parts by mass or less, more preferably 2 parts by mass or more and 10 parts by mass or less.

(Thickness of anisotropic conductive film)
The thickness of the anisotropic conductive film can be appropriately selected depending on the conductive particle diameter, the conductive particle content, the type of the photocurable compound, the purpose of use of the anisotropic conductive film, and is usually 10 μm or more and 30 μm or less. Preferably, it is 10 μm or more and 25 μm or less, and more preferably 10 μm or more and 20 μm or less.

(Total light reflectance of anisotropic conductive film)
The anisotropic conductive film of the present invention is a transparent substrate wiring or connection terminal that is difficult to reach the irradiation light when the connection body is made by anisotropic conductive connection between the connection terminal of the transparent substrate and the electrode of the electronic component. In order to improve the curing rate of the portion in contact with the central portion in the width direction and reduce the conduction resistance, the total light reflectance according to JIS K7375 is 25% or more, preferably 35 to 60%.

  The adjustment of the total light reflectance of the anisotropic conductive film is carried out by adjusting the kind of the light diffusing filler, the light diffusing filler coverage of the conductive particles, and the anisotropic conductive film of the light diffusing filler not coated with the conductive particles. This can be done by selecting and adjusting the abundance. Specifically, when increasing the total light reflectance, for example, it can be performed by increasing the light diffusable filler coverage of the conductive particles, and conversely, when reducing the total light reflectance. Can be performed by reducing the light-diffusing filler coverage of the conductive particles.

<Manufacture of anisotropic conductive film>
The anisotropic conductive film of the present invention is prepared by attaching a light diffusable filler to the surface of a conductive particle with a high-speed stirrer or the like to prepare a light diffusable filler-coated conductive particle. In a binder composition containing a functional compound, a photo-curing agent, and other components such as a solvent and a film-forming resin that are blended as necessary, it is uniformly dispersed by a conventional method to obtain a desired thickness. After film formation, it can be produced by drying at 50 ° C. or higher and 100 ° C. or lower as necessary.

<Connected body>
A connection body is obtained by anisotropic conductive connection between the connection terminal of the transparent substrate and the electrode of the electronic component through the anisotropic conductive film of the present invention, and this connection body is also a part of the present invention. . As the transparent substrate, an ultraviolet light transmissive glass substrate or a plastic substrate can be used, and the materials, width, pitch, etc., used for the conventional transparent substrate can be used for the connection terminals and wiring. . Further, the electronic component is a target of anisotropic conductive connection, and includes an FPC, an IC chip, a liquid crystal panel, and the like.

<Method for manufacturing connected body>
As shown in FIG. 1, the connection body of the present invention has an anisotropic conductive film 3 disposed on a connection terminal 2 of a transparent substrate 1, and an electrode 5 of an electronic component 4 is disposed through the anisotropic conductive film 3. After aligning with the connection terminal 2 of the transparent substrate 1 and pressing from the electronic component 4 side, the transparent substrate 1 is irradiated with ultraviolet rays (arrows in the figure) from the transparent substrate 1 side while preferably maintaining the pressing. It can be manufactured by joining the electronic component 4. In this ultraviolet irradiation, the ultraviolet rays applied to the conductive particles 7 covered with the light diffusing filler 6 in the anisotropic conductive film 3 are directed toward the edge of the anisotropic conductive film 3 by the light diffusing filler 6. Can be diffused, and the curing rate of the photocurable binder composition sandwiched between the connection terminal 2 and the electrode 5 can be improved.

  In addition, as preferable pressing conditions when manufacturing the connection body of the present invention, a pressure of 50 MPa or more and 90 MPa or less, a pressing temperature of 100 ° C. or more and 120 ° C. or less, a pressing time of 3 seconds or more, and preferably 5 seconds or more can be exemplified. . The reason why the ultraviolet rays are irradiated after the pressing is that when the ultraviolet rays are irradiated simultaneously with the pressing, the conductive particles are not sufficiently pushed in and the conduction resistance tends to increase. Thereby, the hardening rate of the anisotropic conductive film of the site | part which contact | connected the wiring direction of the transparent substrate and the width direction center part of the connecting terminal can be improved, and conduction | electrical_connection resistance can be reduced. In addition, the ultraviolet light source and the ultraviolet irradiation conditions in the conventional method for manufacturing a connection body can also be applied to the ultraviolet light source and the ultraviolet irradiation conditions.

  Hereinafter, the present invention will be described with more specific experimental examples.

Example 1
(Preparation of light-diffusing filler-coated conductive particles)
By applying a coating treatment to 20 parts by mass of zinc oxide fine particles having an average particle diameter of 100 nm with respect to 100 parts by mass of conductive particles having an average particle diameter of about 4 μm (AUL704, manufactured by Sekisui Chemical Co., Ltd.), 20% by mass Light diffusing filler-coated conductive particles coated with zinc oxide fine particles were obtained. The coverage of the obtained 50 samples of the light diffusing filler-coated conductive particles with the zinc oxide fine particles was 15%.

(Preparation of anisotropic conductive film)
30 parts by mass of the obtained light-diffusing filler-coated conductive particles, 20 parts by mass of phenoxy resin (YP70, manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.), 30 parts by mass of liquid epoxy resin (EP828, manufactured by Mitsubishi Chemical Corporation), and solid An epoxy resin (YD014, manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.) 20 parts by mass and a photocationic curing agent (LW-S1, manufactured by San Apro Co., Ltd.) 5 parts by mass were mixed with a stirrer (Awatori Rentaro, manufactured by Shinky Corporation). ) To mix evenly. The obtained mixture was applied onto PET after the release treatment so that the average thickness after drying was 20 μm, and dried at 80 ° C. to obtain an anisotropic conductive film.

<Manufacture of joined body>
The following test FPC and glass substrate were used for the production of the joined body.

"Glass substrate"
Wiring material corresponding to bumps of the test IC chip: Al / Cr / Au wiring Wiring width: three types of 0.2 mm, 0.5 mm, and 1.0 mm Average wiring thickness: 0.5 μm
Substrate thickness: 0.7mm

An anisotropic conductive film slit to a width of 1.5 mm is placed on a glass substrate, temporarily attached at 0.5 MPa, 60 ° C., 2 seconds, and a test IC chip is placed thereon to temporarily fix it, Heat press using a buffer material (70 μm thick Teflon (registered trademark)) with a heat tool of 1.5 mm width and pressure bonding conditions of 120 ° C., 80 MPa, 10 seconds (tool speed 25 mm / second, stage temperature 30 ° C.) 5 seconds after the start, while maintaining the heating and pressurization, an LED lamp having a maximum emission wavelength of 360 nm from the glass substrate side (controller: ZUV-C20H, head unit: ZUV-H20MB, lens unit: ZUV-212L, OMRON) UV irradiation was performed for 5 seconds at 400 W / cm ² . Thereby, a joined body was obtained.

Example 2
A light-diffusing filler-coated conductive particle (coverage 20%) was produced in the same manner as in Example 1 except that aluminum oxide having an average particle diameter of 100 nm was used instead of zinc oxide, and anisotropy was obtained using it. A conductive film was produced, and a connection body was produced.

Example 3
Light diffusing filler-coated conductive particles (coverage 45%) were produced in the same manner as in Example 1 except that magnesium oxide having an average particle diameter of 100 nm was used instead of zinc oxide, and anisotropy was obtained using it. A conductive film was produced, and a connection body was produced.

Example 4
A light-diffusing filler-coated conductive particle (coverage 60%) was prepared in the same manner as in Example 1 except that 30 parts by mass of magnesium oxide having an average particle diameter of 100 nm was used instead of 20 parts by mass of zinc oxide. An anisotropic conductive film was prepared using a connector, and a connection body was further prepared.

Example 5
A light-diffusing filler-coated conductive particle (coverage 80%) was prepared in the same manner as in Example 1 except that 40 parts by mass of magnesium oxide having an average particle diameter of 100 nm was used instead of 20 parts by mass of zinc oxide. An anisotropic conductive film was prepared using a connector, and a connection body was further prepared.

Comparative Example 1
5 parts of conductive particles (AUL704, manufactured by Sekisui Chemical Co., Ltd.) having an average particle diameter of about 4 μm which are not coated with a light diffusing filler, 20 parts by mass of phenoxy resin (YP70, manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.), and a liquid epoxy 30 parts by mass of resin (EP828, manufactured by Mitsubishi Chemical Corporation), 20 parts by mass of solid epoxy resin (YD014, manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.), and 5 parts by mass of a cationic cationic curing agent (LW-S1, manufactured by San Apro Co., Ltd.) Were mixed uniformly using a stirrer (Ryotaro Awatori, manufactured by Shinky Co., Ltd.). The obtained mixture was applied onto PET after the release treatment so that the average thickness after drying was 20 μm, and dried at 80 ° C. to obtain an anisotropic conductive film. Moreover, the connection body was produced similarly to Example 1 using the obtained anisotropic conductive film.

Comparative Example 2
An anisotropic conductive film was obtained in the same manner as in Comparative Example 1 except that 6 parts by mass of zinc oxide fine particles having an average particle diameter of 100 nm were further added to the formulation of Comparative Example 1. Moreover, the connection body was produced similarly to Example 1 using the obtained anisotropic conductive film.

Comparative Example 3
An anisotropic conductive film was obtained in the same manner as in Comparative Example 1 except that 12 parts by mass of zinc oxide fine particles having an average particle diameter of 100 nm were further added to the formulation of Comparative Example 1. Moreover, the connection body was produced similarly to Example 1 using the obtained anisotropic conductive film.

<Evaluation>
About the connection body obtained by the Example and the comparative example, "conduction resistance", "hardening rate (%) of wiring center", and "total light reflectance (%)" were tested and evaluated as described below. . The obtained results are shown in Table 1.

"Conduction resistance"
About the connection body, resistance value ((ohm)) of 30 places was measured on conditions of 1 mA of electric currents using the 4 terminal method. Practically, it is desirable that it is 1Ω or less.

"Curing rate of wiring center (%)"
The curing rate of the anisotropic conductive film after photocuring in contact with the center in the planar direction of the wiring of the joined body was examined by a change in the infrared absorption intensity of 914 cm ⁻¹ of the epoxy group. When the infrared absorption intensity before curing is 100 and the infrared absorption intensity after curing is x, the curing rate (%) is obtained as 100-x. In addition, the hardening rate of the anisotropic conductive film which has not overlapped with wiring was 93%.

"Total light reflectance (%)"
The total light reflectivity (%) of the anisotropic conductive film was determined using a total light reflectometer (Hitachi spectrophotometer U-3300, manufactured by Hitachi High-Tech Fielding Co., Ltd.) based on JIS K7375.

  As can be seen from Table 1, the anisotropic conductive films of Examples 1 to 5 containing conductive particles coated with a light diffusing filler exhibited a conduction resistance value of 1Ω or less and no practical problem. . The curing rate is 0.5 mm in width compared not only to Comparative Example 1 in which no light diffusing filler is used, but also to Comparative Examples 2 and 3 in which the conductive particles are uniformly dispersed throughout the film. Compared to the curing rate of the anisotropic conductive film at the center in the plane direction of the wiring having a width of 1 mm, it was greatly improved.

  In the anisotropic conductive film of the present invention, at least a part of the surface of the conductive particles to be used is coated with a light diffusing filler, and the total light reflectance according to JIS K7375 is 25% or more. For this reason, when creating a connection body by anisotropically connecting the connection terminal of the transparent substrate and the electrode of the electronic component through this anisotropic conductive film, the width direction of the wiring of the transparent substrate and the connection terminal Since the hardening rate of the site | part which contact | connected the center part can be improved and connection resistance can be reduced, it is useful when mounting electronic components, such as an IC chip, on a transparent substrate.

DESCRIPTION OF SYMBOLS 1 Transparent substrate 2 Terminal for connection 3 Anisotropic conductive film 4 Electronic component 5 Electrode 6 Light diffusing filler 7 Conductive particle

Claims (6)

  An anisotropic conductive film comprising a binder composition containing a photocurable compound and a photocuring agent and conductive particles dispersed therein, wherein at least a part of the surface of the conductive particles is light diffusive An anisotropic conductive film which is covered with filler and has a JIS K7375 total light reflectance of 25% or more.   The anisotropic conductive film according to claim 1, wherein 15% or more of the surface of the conductive particles is coated with a light diffusing filler.   The anisotropic conductive film according to claim 1 or 2, wherein a ratio of the light diffusing filler not covering the conductive particles to the total light diffusing filler in the anisotropic conductive film is 4 to 15% by mass.   The anisotropic conductive film according to claim 1, wherein the light diffusing filler is an inorganic oxide.   The connection body by which the connection terminal of the transparent substrate and the electrode of the electronic component are anisotropically conductive-connected through the anisotropic conductive film in any one of Claims 1-4.   6. The method of manufacturing a connection body according to claim 5, wherein an anisotropic conductive film is arranged on the connection terminal of the transparent substrate, and the electrode of the electronic component is connected to the connection terminal of the transparent substrate through the anisotropic conductive film. A manufacturing method for joining a transparent substrate and an electronic component by aligning and pressing from the electronic component side and then irradiating ultraviolet rays from the transparent substrate side.

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