KR20220068267A - Conductive material - Google Patents

Abstract

An electrically-conductive material from which the conduction|electrical_connection reliability outstanding with respect to an oxide layer is obtained is provided. The conductive material includes a resin core particle 10 , a plurality of insulating particles 20 disposed on the surface of the resin core particle 10 to form the projection 30a, the resin core particle 10 and the insulating particle 20 . The conductive layer 30 arrange|positioned on the surface of ) is provided, and the Mohs' Hardness of the insulating particle 20 contains the larger electroconductive particle than 7. Thereby, electroconductive particle penetrates through the oxide layer on the surface of an electrode, and fully penetrates, and the outstanding conduction|electrical_connection reliability is acquired.

Description

conductive material {CONDUCTIVE MATERIAL}

This invention relates to the electrically-conductive material which electrically connects circuit members. This application claims priority on the basis of Japanese Patent Application No. 2014-220448 for which it applied in Japan on October 29, 2014, and Japanese Patent Application No. 2015-201767 for which it applied on October 13, 2015, The application is incorporated herein by reference.

In recent years, IZO (Indium Zinc Oxide) is used as wiring of a circuit member instead of ITO (Indium Tin Oxide) with high production cost. The IZO wiring has a smooth surface, and an oxide layer (passivation) is formed on the surface. Moreover, in aluminum wiring, for example, in order to prevent corrosion, the protective layer _of oxide layers, such as TiO2, may be formed in the surface.

However, since an oxide layer is hard, in the conventional electrically-conductive material, electroconductive particle did not penetrate fully through an oxide layer, but sufficient conduction|electrical_connection reliability was not acquired in some cases.

Japanese Patent Laid-Open No. 2013-149613

The present invention has been proposed in view of such a conventional situation, and provides an electrically conductive material having excellent conduction reliability with respect to an oxide layer.

As a result of this inventor earnestly examining, it discovered that the outstanding conduction resistance was obtained by making Mohs' Hardness of the insulating particle which forms the processus|protrusion of electroconductive particle larger than a predetermined value.

That is, the conductive material according to the present invention comprises a resin core particle, a plurality of insulating particles disposed on the surface of the resin core particle to form projections, and a conductive layer disposed on the surface of the resin core particle and the insulating particle. It is provided, and the Mohs' Hardness of the said insulating particle contains larger than 7 electroconductive particle, It is characterized by the above-mentioned.

Further, the bonded structure according to the present invention comprises a resin core particle, a plurality of insulating particles disposed on the surface of the resin core particle to form a projection, and a conductive layer disposed on the surface of the resin core particle and the insulating particle. It is provided, and the terminal of a 1st circuit member and the terminal of a 2nd circuit member are connected by the electroconductive particle whose Mohs' Hardness of the said insulating particle is larger than 7, It is characterized by the above-mentioned.

Further, in the method for manufacturing a bonded structure according to the present invention, a resin core particle, a plurality of insulating particles disposed on the surface of the resin core particle to form a projection, and the resin core particle and the insulating particle disposed on the surface of the insulating particle It is characterized by crimping|bonding the terminal of a 1st circuit member and the terminal of a 2nd circuit member through the electrically-conductive material which provided a conductive layer and contains the electroconductive particle whose Mohs' Hardness of the said insulating particle is larger than 7.

ADVANTAGE OF THE INVENTION According to this invention, since the Mohs' Hardness of the insulating particle which forms a processus|protrusion is large, electroconductive particle penetrates through the oxide layer of an electrode surface sufficiently, and the outstanding conduction|electrical_connection reliability is acquired.

BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which shows the outline of the 1st structural example of electroconductive particle.
It is sectional drawing which shows the outline of the 2nd structural example of electroconductive particle.
3 : is sectional drawing which shows the outline of the 3rd structural example of electroconductive particle.
It is sectional drawing which shows the outline of the electroconductive particle at the time of crimping|bonding.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described in detail in the following order, referring drawings.

1. Conductive Particles

2. conductive material

3. Manufacturing method of bonded structure

4. Examples

<1. Electroconductive particle>

The conductive particles according to the present embodiment include a resin core particle, a plurality of insulating particles disposed on the surface of the resin core particle to form a projection, and a conductive layer disposed on the surface of the resin core particle and the insulating particle, Mohs' Hardness of insulating particle is larger than 7. Thereby, electroconductive particle penetrates through the oxide layer on the surface of an electrode, and fully penetrates, and the outstanding conduction|electrical_connection reliability is acquired. In particular, when the circuit member as an adherend is a low elastic modulus plastic substrate such as a PET (Poly Ethylene Terephthalate) substrate, it is possible to realize low resistance by reducing the effect of deformation of the substrate without increasing the pressure during compression. Valid.

[First configuration example]

BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which shows the outline of the 1st structural example of electroconductive particle. The electroconductive particle of a 1st structural example is the resin core particle 10, the insulating particle 20 which adheres to the surface of the resin core particle 10, and becomes the core material of the processus|protrusion 30a, The resin core particle 10 and a conductive layer (30) covering the insulating particles (20).

Examples of the resin core particles 10 include benzoguanamine resins, acrylic resins, styrene resins, silicone resins, polybutadiene resins, and the like, and at least two or more types of repeating units based on monomers constituting these resins The copolymer which has the combined structure is mentioned. Among these, it is preferable to use the copolymer obtained by combining divinylbenzene, tetramethylolmethane tetraacrylate, and styrene.

Moreover, it is preferable that the compressive elastic modulus (20% K value) when the resin core particle 10 is compressed 20% is 500-20000 N/mm<2>. When the 20% K value of the resin core particle 10 is within the above range, as a result, the projections can penetrate the oxide layer on the electrode surface. For this reason, an electrode and the conductive layer of electroconductive particle fully contact and can reduce the connection resistance between electrodes.

The compressive elastic modulus (20% K value) of the resin core particle 10 can be measured as follows. Electroconductive particles are compressed under the conditions of a compression rate of 2.6 mN/sec and a maximum test load of 10 gf in a smooth indenter cross section of a circumference (50 µm in diameter, made of diamond) using a micro compression tester. At this time, the load value (N) and the compression displacement (mm) are measured. From the obtained measured value, the compressive elastic modulus (20% K value) can be calculated|required by the following formula. Moreover, as a micro compression tester, "Fischer Scope H-100" by a Fisher company, etc. are used, for example.

K value (N/㎟) = (3/2 ^1/2 ) F S ^-3/2 R ^-1/2

F: Load value (N) when the conductive particles are compressed by 20%

S: Compressive displacement (mm) when conductive particles are compressed by 20%

R: Radius of conductive particles (mm)

It is preferable that the average particle diameter of the resin core particle 10 is 2-10 micrometers. In this specification, the average particle diameter means the particle diameter (D50) at 50% of the integrated value in the particle size distribution calculated|required by the laser diffraction/scattering method.

The insulating particle 20 adheres to the surface of the resin core particle 10 in multiple numbers, and becomes the core material of the processus|protrusion 30a for piercing|piercing the oxide layer of the electrode surface. As for the insulating particle 20, Mohs' Hardness is larger than 7, and it is preferable that it is 9 or more. When the hardness of the insulating particle 20 is high, the projection 30a can penetrate the oxide on the electrode surface. Moreover, when the core material of the processus|protrusion 30a is the insulating particle 20, compared with the time of using electroconductive particle, the factor of migration decreases.

Examples of the insulating particles 20 include zirconia (Mohs hardness 8 to 9), alumina (Mohs hardness 9), tungsten carbide (Mohs hardness 9) and diamond (Mohs hardness 10), and these may be used alone, You may use it in combination of 2 or more types. Among these, it is preferable to use alumina from a viewpoint of economical efficiency.

Moreover, the average particle diameter of the insulating particle 20 becomes like this. Preferably they are 50 nm or more and 250 nm or less, More preferably, they are 100 nm or more and 200 nm or less. Moreover, the number of the processus|protrusions formed on the surface of the resin core particle 20 becomes like this. Preferably it is 1-500, More preferably, it is 30-200. By forming a predetermined number of projections 30a on the surface of the resin core particle 20 using the insulating particles 20 having such an average particle diameter, the projections 30a penetrate the oxide on the electrode surface, and the connection resistance between the electrodes can be effectively lowered.

The conductive layer 30 coats the resin core particles 10 and the insulating particles 20 , and has projections 30a raised by the plurality of insulating particles 20 . The conductive layer 30 is preferably nickel or a nickel alloy. Ni-W-B, Ni-W-P, Ni-W, Ni-B, Ni-P etc. are mentioned as a nickel alloy. Among these, it is preferable to use low resistance Ni-W-B.

Moreover, the thickness of the conductive layer 30 becomes like this. Preferably they are 50 nm or more and 250 nm or less, More preferably, they are 80 nm or more and 150 nm or less. When the thickness of the conductive layer 30 is too small, it will become difficult to make it function as electroconductive particle, and when thickness is too big|large, the height of the processus|protrusion 30a will disappear.

The electroconductive particle of a 1st structural example can be obtained with the method of forming the conductive layer 30, after making the insulating particle 20 adhere to the surface of the resin core particle 10. Moreover, as a method of making the insulating particle 20 adhere on the surface of the resin core particle 10, for example, in the dispersion liquid of the resin core particle 10, the insulating particle 20 is added, and the resin core particle In the surface of (10), for example, making the insulating particle 20 accumulate|stacking by van der Waals force, making it adhere, etc. are mentioned. Moreover, as a method of forming a conductive layer, the method by electroless plating, the method by electroplating, the method by physical vapor deposition, etc. are mentioned, for example. Among these, the method by electroless-plating which formation of a conductive layer is simple is preferable.

[Second configuration example]

It is sectional drawing which shows the outline of the 2nd structural example of electroconductive particle. The electroconductive particle of a 2nd structural example is the resin core particle 10, the insulating particle 20 which adheres to the surface of the resin core particle 10, and becomes the core material of the protrusion 32a, The resin core particle 10 And the 1st conductive layer 31 which coat|covers the surface of the insulating particle 20, and the 2nd conductive layer 32 which coat|covers the conductive layer 31 are provided. That is, in the second structural example, the conductive layer 30 of the first structural example has a two-layer structure. By making a conductive layer into a two-layer structure, the adhesiveness of the 2nd conductive layer 32 which comprises outermost can be improved and conduction resistance can be reduced.

Since the resin core particle 10 and the insulating particle 20 are the same as that of a 1st structural example, description is abbreviate|omitted here.

The 1st conductive layer 31 coat|covers the surface of the resin core particle 10 and the insulating particle 20, and becomes the foundation|substrate of the 2nd conductive layer 32. As shown in FIG. It will not specifically limit as the 1st conductive layer 31, if the adhesiveness of the 2nd conductive layer 32 improves, For example, nickel, a nickel alloy, copper, silver, etc. are mentioned.

The 2nd conductive layer 32 coat|covers the 1st conductive layer 31, and has the protrusion 32a protruded by the some insulating particle 20. It is preferable that the 2nd conductive layer 32 is nickel or a nickel alloy similarly to a 1st structural example. Ni-W-B, Ni-W-P, Ni-W, Ni-B, Ni-P etc. are mentioned as a nickel alloy. Among these, it is preferable to use Ni-W-B which is low resistance.

The total thickness of the first conductive layer 31 and the second conductive layer 32 is the same as that of the conductive layer 30 of the first structural example, preferably 50 nm or more and 250 nm or less, more preferably 80 nm or more and 150 nm or less. When total thickness is too small, it will become difficult to make it function as electroconductive particle, and when total thickness is too big|large, the height of the processus|protrusion 32a will disappear.

Method of forming the 2nd conductive layer 32, after the electroconductive particle of a 2nd structural example makes the insulating particle 20 adhere to the surface of the resin core particle 10, and forms the 1st conductive layer 31 can be obtained by Moreover, as a method of making the insulating particle 20 adhere on the surface of the resin core particle 10, for example, the insulating particle 20 is added to the dispersion liquid of the resin core particle 10, and the resin core particle ( 10), for example, making the insulating particle 20 accumulate|stacking by van der Waals force, making it adhere to the surface, etc. are mentioned. Moreover, as a method of forming the 1st conductive layer 31 and the 2nd conductive layer 32, the method by electroless plating, the method by electroplating, the method by physical vapor deposition, etc. are mentioned, for example. have. Among these, the method by electroless-plating which formation of a conductive layer is simple is preferable.

[Third configuration example]

3 : is sectional drawing which shows the outline of the 3rd structural example of electroconductive particle. The conductive particles of the third structural example are adhered to the resin core particle 10, the first conductive layer 33 covering the surface of the resin core particle 10, and the surface of the first conductive layer 33, The insulating particle 20 used as the core material of the projection 34a, and the 1st conductive layer 33 and the 2nd conductive layer 34 which coat|cover the surface of the insulating particle 20 are provided. That is, in the 3rd structural example, the insulating particle 20 was made to adhere to the surface of the 1st conductive layer 33, and the 2nd conductive layer 34 was further formed. This prevents the insulating particles 20 from penetrating into the resin core particles 10 at the time of compression, so that the projections can easily penetrate the oxide layer on the electrode surface.

Since the resin core particle 10 and the insulating particle 20 are the same as that of a 1st structural example, description is abbreviate|omitted here.

The 1st conductive layer 33 coat|covers the surface of the resin core particle 10, and serves as the attachment surface of the insulating particle 20, and the foundation|substrate of the 2nd conductive layer 34. As shown in FIG. It will not specifically limit as the 1st conductive layer 33, if the adhesiveness of the 2nd conductive layer 34 improves, For example, nickel, a nickel alloy, copper, silver, etc. are mentioned.

Moreover, the thickness of the 1st conductive layer 33 becomes like this. Preferably they are 10 nm or more and 200 nm or less, More preferably, they are 50 nm or more and 150 nm or less. Since the effect of elasticity of the resin core particle 10 will fall when thickness is too large, conduction|electrical_connection reliability will fall.

The 2nd conductive layer 34 coat|covers the insulating particle 20 and the 1st conductive layer 33, and has the protrusion 34a protruded by the some insulating particle 20. As shown in FIG. It is preferable that the 2nd conductive layer 34 is nickel or a nickel alloy similarly to a 1st structural example. Ni-W-B, Ni-W-P, Ni-W, Ni-B, Ni-P etc. are mentioned as a nickel alloy. Among these, it is preferable to use Ni-W-B which is low resistance.

Moreover, the thickness of the 2nd conductive layer 34 becomes like the conductive layer 30 of 1st structural example, Preferably they are 50 nm or more and 250 nm or less, More preferably, they are 80 nm or more and 150 nm or less. When total thickness is too small, it will become difficult to make it function as electroconductive particle, and when total thickness is too big|large, the height of the processus|protrusion 34a will disappear.

The electroconductive particle of a 3rd structural example forms the 1st conductive layer 33 on the surface of the resin core particle 10, After making the insulating particle 20 adhere, the method of forming the 2nd conductive layer 34 can be obtained by Moreover, as a method of making the insulating particle 20 adhere on the surface of the 1st conductive layer 33, for example, in the dispersion liquid of the resin core particle 10 in which the 1st conductive layer 33 was formed, insulating particle|grains (20) is added, the insulating particle 20 is accumulated on the surface of the 1st conductive layer 33 by van der Waals force, for example, and making it adhere, etc. are mentioned. Moreover, as a method of forming the 1st conductive layer 33 and the 2nd conductive layer 34, the method by electroless plating, the method by electroplating, the method by physical vapor deposition, etc. are mentioned, for example. have. Among these, the method by electroless-plating which formation of a conductive layer is simple is preferable.

<2. Conductive material>

The electrically-conductive material which concerns on this embodiment is provided with a resin core particle, the insulating particle which is arrange|positioned on the surface of a resin core particle in plurality and forms a projection, and a conductive layer arranged on the surface of the resin core particle and the insulating particle, and has insulating properties. The Mohs' Hardness of particle|grains contains the larger electroconductive particle than 7. As an electrically-conductive material, shapes, such as a film form and a paste form, are mentioned, For example, an anisotropic conductive film (ACF:Anisotropic Conductive Film), an anisotropic electrically conductive paste (ACP:Anisotropic Conductive Paste), etc. are mentioned. Moreover, as a hardening type of an electrically-conductive material, a thermosetting type, a photocuring type, a light-heat combined curing type, etc. are mentioned.

Hereinafter, a thermosetting anisotropic conductive film having a two-layer structure in which an ACF layer containing conductive particles and an NCF (Non Conductive Film) layer not containing conductive particles is laminated will be described as an example. Moreover, as a thermosetting type anisotropic conductive film, although a cation hardening type, an anion hardening type, a radical hardening type, or these can be used together, for example, An anion hardening type anisotropic conductive film is demonstrated here.

As for the anion-curable anisotropic conductive film, an ACF layer and an NCF layer contain a film-forming resin, an epoxy resin, and an anionic polymerization initiator as a binder.

Film-forming resin corresponds to high molecular weight resin with an average molecular weight of 10000 or more, for example, It is preferable from a viewpoint of film formation that it is an average molecular weight of about 10000-80000. Various resins, such as a phenoxy resin, a polyester resin, a polyurethane resin, a polyester urethane resin, an acrylic resin, a polyimide resin, a butyral resin, are mentioned as a film-forming resin, These may be used independently, You may use it in combination of 2 or more types. Among these, it is preferable to use a phenoxy resin suitably from viewpoints, such as a film-forming state and connection reliability.

The epoxy resin forms a three-dimensional network structure and provides favorable heat resistance and adhesiveness, and it is preferable to use a solid epoxy resin and a liquid epoxy resin together. Here, a solid epoxy resin means the epoxy resin which is solid at normal temperature. In addition, a liquid epoxy resin means a liquid epoxy resin at normal temperature. In addition, normal temperature means the temperature range of 5-35 degreeC prescribed|regulated by JISZ8703.

The solid epoxy resin is not particularly limited as long as it is compatible with the liquid epoxy resin and is in a solid state at room temperature, and bisphenol A epoxy resin, bisphenol F epoxy resin, polyfunctional epoxy resin, dicyclopentadiene epoxy resin, novolac phenol A type epoxy resin, a biphenyl type epoxy resin, a naphthalene type epoxy resin, etc. are mentioned, Among these, 1 type can be used individually or in combination of 2 or more type. Among these, it is preferable to use a bisphenol A epoxy resin. As a specific example available in the market, the brand name "YD-014" of Shin-Nitetsu Sumikin Chemical Co., Ltd. etc. is mentioned.

The liquid epoxy resin is not particularly limited as long as it is liquid at room temperature, and bisphenol A type epoxy resin, bisphenol F type epoxy resin, novolac phenol type epoxy resin, naphthalene type epoxy resin, etc. or in combination of two or more. In particular, it is preferable to use a bisphenol A epoxy resin from the viewpoints of film tackiness, flexibility, and the like. Specific examples available on the market include Mitsubishi Chemical Co., Ltd. trade name "EP828".

As an anionic polymerization initiator, a well-known hardening|curing agent used normally can be used. For example, organic acid dihydrazide, dicyandiamide, amine compound, polyamideamine compound, cyanate ester compound, phenol resin, acid anhydride, carboxylic acid, tertiary amine compound, imidazole, Lewis acid, breth A ted acid salt, a polymercaptan type hardening|curing agent, a urea resin, a melamine resin, an isocyanate compound, a blocked isocyanate compound, etc. are mentioned, Among these, 1 type can be used individually or in combination of 2 or more types. Among these, it is preferable to use a microcapsule-type latent curing agent formed by using an imidazole-modified product as a nucleus and coating the surface with polyurethane. As a specific example available in the market, the brand name of Asahi Kasei Materials Co., Ltd. "Novacure 3941HP", etc. are mentioned.

Moreover, as a binder, you may mix|blend a stress reliever, a silane coupling agent, an inorganic filler, etc. as needed. Examples of the stress reliever include a hydrogenated styrene-butadiene block copolymer and a hydrogenated styrene-isoprene block copolymer. Moreover, as a silane coupling agent, an epoxy type, methacryloxy type, an amino type, a vinyl type, a mercapto sulfide type, a ureide type, etc. are mentioned. Moreover, as an inorganic filler, a silica, a talc, a titanium oxide, a calcium carbonate, magnesium oxide, etc. are mentioned.

<3. Manufacturing method of bonded structure>

A method for manufacturing a bonded structure according to the present embodiment includes a resin core particle, a plurality of insulating particles disposed on the surface of the resin core particle to form projections, and a conductive layer disposed on the surface of the resin core particle and the insulating particle And the terminal of a 1st circuit member and the terminal of a 2nd circuit member are crimped|bonded through the electrically-conductive material containing the electroconductive particle whose Mohs' Hardness of insulating particle|grains is larger than 7. Thereby, the bonded structure by which the terminal of a 1st circuit member and the terminal of a 2nd circuit member are connected with the electroconductive particle mentioned above can be obtained.

There is no restriction|limiting in particular for a 1st circuit member and a 2nd circuit member, According to the objective, it can select suitably. As a 1st circuit member, plastic substrates, such as an LCD (Liquid Crystal Display) panel use, a plasma display panel (PDP) use, a glass substrate, a printed wiring board (PWB), etc. are mentioned, for example. Moreover, as a 2nd circuit member, flexible boards (FPC:Flexible Printed Circuits), such as IC (Integrated Circuit) and COF (Chip On Film), a tape carrier package (TCP) board|substrate, etc. are mentioned, for example.

It is sectional drawing which shows the outline of the electroconductive particle at the time of crimping|bonding. In FIG. 4, a conductive layer is abbreviate|omitted. The conductive particles 40 have an oxide layer formed on the terminals 51 of the first circuit member 50 ( 52) becomes possible. The oxide layer 52 functions as a protective layer which prevents corrosion _of wiring, for example, TiO2, SnO2 _, SiO2 _, etc. are mentioned.

In this embodiment, since the Mohs' Hardness of the insulating particle 41 is larger than 7, the oxide layer 52 can be penetrated without raising the pressure at the time of crimping|compression-bonding, and generation|occurrence|production of a wiring crack can be suppressed. In particular, when the first circuit member 50 is a low elastic modulus plastic substrate such as a PET (Poly Ethylene Terephthalate) substrate, it is possible to realize low resistance by reducing the effect of deformation of the substrate without increasing the pressure during compression. Therefore, it is very effective. In addition, the elastic modulus of a plastic substrate can be calculated|required in consideration of factors, such as the relationship between the flexibility requested|required of a connection body, flexibility, and the connection strength with electronic components, such as the drive circuit element 3 mentioned later, although it is generally It becomes 2000 Mpa - 4100 Mpa.

In crimping of the terminal of the first circuit member and the terminal of the second circuit member, on the second circuit member, the crimping tool heated to a predetermined temperature is used for a predetermined pressure and for a predetermined time, and is heat-pressed to perform main crimping. Here, it is preferable that predetermined pressure is 10 MPa or more and 80 MPa or less from a viewpoint of preventing the wiring crack of a circuit member. Moreover, predetermined temperature is the temperature of the anisotropic conductive film at the time of crimping|bonding, and it is preferable that they are 80 degreeC or more and 230 degrees C or less.

There is no restriction|limiting in particular as a crimping tool, It can select suitably according to the objective, You may pressurize once using the pressurizing member larger area than the press object, Moreover, how many pressurizations are carried out using the pressurization member smaller in area than the press object. You may divide and carry out it sequentially. There is no restriction|limiting in particular as a front-end|tip shape of a crimping|compression-bonding tool, According to the objective, it can select suitably, For example, a flat shape, a curved shape, etc. are mentioned. Moreover, when the tip shape is curved, it is preferable to press along the curved shape.

Moreover, you may attach and thermocompression-bonding between a crimping|compression-bonding tool and a 2nd circuit member via a cushioning material. By attaching via a cushioning material, while being able to reduce a pressurization deviation, it can prevent that a crimping|compression-bonding tool is contaminated. The cushioning material consists of a sheet-like elastic material or a calcined body, for example, silicone rubber or polytetrafluoroethylene is used.

According to the manufacturing method of such a bonded structure, since the Mohs' Hardness of an insulating particle is large, an oxide layer can be penetrated without increasing the pressure at the time of crimping|compression-bonding, and generation|occurrence|production of a wiring crack can be suppressed. Moreover, when the conductive layer is made of a material having a high hardness such as Ni-W-B, the oxide layer can be easily penetrated without increasing the pressure at the time of crimping, and the occurrence of wiring cracks can be further suppressed.

Example

<3. Example>

Hereinafter, an embodiment of the present invention will be described. In the present Example, the electroconductive particle which has processus|protrusion was manufactured, and the bonded structure was manufactured using the anisotropic conductive film containing this. And the conduction resistance of the bonded structure and the incidence rate of wiring cracks were evaluated. In addition, the present invention is not limited to these examples.

Manufacture of an anisotropic conductive film, manufacture of a bonded structure, the measurement of conduction resistance, and calculation of the incidence rate of a wiring crack were performed as follows.

[Production of anisotropic conductive film]

An anisotropic conductive film having a two-layer structure in which an ACF layer and an NCF layer were laminated was prepared. First, 20 parts by mass of phenoxy resin (YP50, Shin-Nitetsu Chemical Co., Ltd.), 30 parts by mass of liquid epoxy resin (EP828, Mitsubishi Chemical Co., Ltd.), 30 parts by mass of solid epoxy resin (YD-014, Shin-Nitetsu Chemical Co., Ltd.) 10 mass parts, 30 mass parts of microcapsule-type latent hardening|curing agents (Novacure 3941H, Asahi Kasei Materials), 10 mass parts of electroconductive particles were mix|blended, and the 6-micrometer-thick ACF layer was obtained. Next, 20 parts by mass of a phenoxy resin (YP50, Shin-Nitetsu Chemical Co., Ltd.), 30 parts by mass of a liquid epoxy resin (EP828, Mitsubishi Chemical Co., Ltd.), 30 parts by mass of a solid epoxy resin (YD-014, Shin-Nitetsu Chemical Co., Ltd.) ) 10 parts by mass and 30 parts by mass of a microcapsule latent curing agent (Novacure 3941H, Asahi Kasei Materials) were blended to obtain an NCF layer having a thickness of 12 µm. And the ACF layer and the NCF layer were bonded together, and the anisotropic conductive film of the 18 micrometer-thick 2-layer structure was obtained.

[Manufacture of bonded structure]

As the evaluation substrate, TiO ₂ /Al coated glass substrate (0.3 mmt, TiO ₂ thickness: 50 nm, Al thickness: 300 nm), TiO ₂ /Al coated PET (Poly Ethylene Terephthalate) substrate (0.3 mmt, TiO ₂ thickness) : 50 nm, Al thickness: 300 nm), and IC (1.8 mm × 20 mm, T: 0.3 mm, Au-plated bump: 30 μm × 85 μm, h=15 μm) were prepared. In addition, crimping|compression-bonding conditions were 190 degreeC - 60 MPa-5 sec, or 190 degreeC - 100 MPa-5 sec.

First, on a TiO ₂ /Al-coated glass substrate or TiO ₂ /Al-coated PET substrate, an anisotropic conductive film slit to a width of 1.5 mm is temporarily adhered using a press, and the peeled PET film is peeled off, and then the IC is pressed by a press. It was used and crimped|bonded under predetermined crimping|compression-bonding conditions, and the bonded structure was obtained.

[Measurement of continuity resistance]

The conduction resistance (Ω) of the initial bonding structure was measured using the digital multimeter (Brand name: Digital multimeter 7561, the Yokogawa Electric company make). Moreover, after leaving the bonded structure to stand for 500 hours in 85 degreeC and the high-temperature, high-humidity environment of 85 %RH and performing a reliability test, the conduction resistance (Ω) of the bonded structure was measured.

[Rate of wiring cracks]

Arbitrary 20 points|pieces of the wiring by the side of the board|substrate of the bonded structure were observed with the metallurgical microscope, the wiring crack was counted, and the incidence rate was computed.

[Total judgment]

The case where the difference between the initial conduction resistance and the conduction resistance after the reliability test was 0.3 Ω or less and the occurrence rate of wiring cracks was 0% was evaluated as "OK", and the others were evaluated as "NG".

<Example 1>

As the resin core particles, divinylbenzene-based resin particles were prepared as follows. Benzoyl peroxide as a polymerization initiator was added to a solution in which the mixing ratio of divinylbenzene, styrene, and butyl methacrylate was adjusted, heated while uniformly stirring at high speed, and polymerization was carried out to obtain a fine particle dispersion. The fine particle dispersion liquid was filtered and the block body which is an aggregate of fine particles was obtained by drying under reduced pressure. And divinylbenzene-type resin particle|grains with an average particle diameter of 3.0 micrometers were obtained by grind|pulverizing a block body. The compressive elastic modulus (20% K value) of this resin core particle|grains when it compressed 20% was 12000 N/mm<2>.

Moreover, _the alumina (Al2O3) whose _average particle diameter is 150 nm was used as insulating particle|grains. Further, as the plating solution for the conductive layer, a nickel plating solution containing a nickel plating solution (pH8.5) containing 0.23 mol/L of nickel sulfate, 0.25 mol/L of dimethylamine borane, and 0.5 mol/L of sodium citrate was used.

First, with respect to 100 parts by mass of an alkali solution containing 5 wt% of a palladium catalyst solution, 10 parts by mass of the resin core particles were dispersed by an ultrasonic disperser, and then the solution was filtered to take out the resin core particles. Next, 10 parts by mass of the resin core particles were added to 100 parts by mass of a 1 wt% solution of dimethylamine borane to activate the surface of the resin core particles. And the dispersion liquid containing the resin core particle to which palladium adhered was obtained by adding and disperse|distributing the resin core particle to 500 mass parts of distilled water after fully washing with water.

Next, 1 g of insulating particles were added to the dispersion over 3 minutes to obtain a slurry containing particles to which insulating particles adhered. And stirring the slurry at 60 degreeC, the nickel plating liquid was gradually dripped in the slurry, and electroless nickel plating was performed. After confirming that foaming of hydrogen stopped, it vacuum-dried after filtering particle|grains, washing with water, and alcohol substitution, and obtained the electroconductive particle which has the processus|protrusion formed from alumina, and the conductive layer of Ni-B plating. As a result of observing this electroconductive particle with a scanning electron microscope (SEM), the average particle diameter was 3-4 micrometers, the number of processus|protrusions per particle was about 70, and the thickness of the conductive layer was about 100 nm.

As shown in Table 1, using the anisotropic conductive film to which this electroconductive particle was added, the TiO2/Al _- coated glass substrate and IC were crimped|bonded under the crimping|compression-bonding conditions of 190 degreeC-60 Mpa-5 sec, and bonded structure was obtained. The initial resistance value of the bonded structure was 0.6 Ω, the resistance value after the reliability test was 0.9 Ω, and the rate of occurrence of wiring cracks was 0%, and overall judgment was OK.

<Example 2>

As shown in Table 1, using the anisotropic conductive film to which the same conductive particles as in Example 1 were added, the TiO ₂ /Al-coated PET substrate and the IC were pressed under the compression conditions of 190 ° C.-60 MPa-5 sec, and connected. struct was obtained. The initial resistance value of the bonded structure was 0.7 Ω, the resistance value after the reliability test was 1.0 Ω, and the occurrence rate of wiring cracks was 0%, and overall judgment was OK.

<Example 3>

As the plating solution for the conductive layer, a Ni-W-B plating solution (pH8.5) containing 0.23 mol/L of nickel sulfate, 0.25 mol/L of dimethylamine borane, 0.5 mol/L of sodium citrate, and 0.35 mol/L of sodium tungstate was used. . Except this, it carried out similarly to Example 1, and obtained the electroconductive particle which has the processus|protrusion formed from alumina, and the conductive layer of Ni-W-B plating. As a result of observing this electroconductive particle with the metallographic microscope, the average particle diameter was 3-4 micrometers, the number of processus|protrusions per particle was about 70, and the thickness of the conductive layer was about 100 nm.

As shown in Table 1, using the anisotropic conductive film to which this electroconductive particle was added, the TiO2/Al _- coated glass substrate and IC were crimped|bonded under the crimping|compression-bonding conditions of 190 degreeC-60 Mpa-5 sec, and bonded structure was obtained. The initial resistance value of the bonded structure was 0.3 Ω, the resistance value after the reliability test was 0.5 Ω, and the rate of occurrence of wiring cracks was 0%, and overall judgment was OK.

<Example 4>

As shown in Table 1, using the anisotropic conductive film to which the same conductive particles as in Example 3 were added, the TiO ₂ /Al-coated PET substrate and the IC were pressed under the compression conditions of 190° C.-60 MPa-5 sec, and connected. struct was obtained. The initial resistance value of the bonded structure was 0.6 Ω, the resistance value after the reliability test was 0.8 Ω, and the occurrence rate of wiring cracks was 0%, and overall judgment was OK.

<Comparative Example 1>

As the insulating particles, silica (SiO ₂ ) having an average particle diameter of 150 nm was used. Except this, it carried out similarly to Example 1, and obtained the electroconductive particle which has the processus|protrusion formed from silica, and the conductive layer of Ni-B plating. As a result of observing this electroconductive particle with the metallographic microscope, the average particle diameter was 3-4 micrometers, the number of processus|protrusions per particle was about 70, and the thickness of the conductive layer was about 100 nm.

As shown in Table 1, using the anisotropic conductive film to which this electroconductive particle was added, the TiO2/Al _- coated glass substrate and IC were crimped|bonded under the crimping|compression-bonding conditions of 190 degreeC-60 Mpa-5 sec, and bonded structure was obtained. The initial resistance value of the bonded structure was 1.5 Ω, the resistance value after the reliability test was 3.0 Ω, and the occurrence rate of wiring cracks was 0%, and the overall judgment was NG.

<Comparative Example 2>

As shown in Table 1, using the anisotropic conductive film to which the same conductive particles as in Comparative Example 1 were added, the TiO ₂ /Al-coated PET substrate and the IC were pressed under the compression conditions of 190 ° C.-60 MPa-5 sec, and connected. struct was obtained. The initial resistance value of the bonded structure was 3.0 Ω, the resistance value after the reliability test was 6.0 Ω, and the rate of occurrence of wiring cracks was 0%, and the overall judgment was NG.

<Comparative example 3>

As the insulating particles, silica (SiO ₂ ) having an average particle diameter of 150 nm was used. As the plating solution for the conductive layer, a Ni-WB plating solution (pH8.5) containing 0.23 mol/L of nickel sulfate, 0.25 mol/L of dimethylamine borane, 0.5 mol/L of sodium citrate, and 0.35 mol/L of sodium tungstate was used. was used. Except this, it carried out similarly to Example 1, and obtained the electroconductive particle which has the processus|protrusion formed from silica, and the conductive layer of Ni-WB plating. As a result of observing this electroconductive particle with the scanning electron microscope (SEM), the average particle diameter was 3-4 micrometers, the number of processus|protrusions per particle was about 70, and the thickness of the conductive layer was about 100 nm.

As shown in Table 1, using the anisotropic conductive film to which this electroconductive particle was added, the TiO2/Al _- coated glass substrate and IC were crimped|bonded under the crimping|compression-bonding conditions of 190 degreeC-60 Mpa-5 sec, and bonded structure was obtained. The initial resistance value of the bonded structure was 0.7 Ω, the resistance value after the reliability test was 1.1 Ω, the rate of occurrence of wiring cracks was 0%, and the overall judgment was NG.

<Comparative Example 4>

As shown in Table 1, using the anisotropic conductive film to which the same conductive particles as in Comparative Example 3 were added, the TiO ₂ /Al-coated PET substrate and the IC were pressed under the crimping conditions of 190° C.-60 MPa-5 sec to connect, struct was obtained. The initial resistance value of the bonded structure was 1.8 Ω, the resistance value after the reliability test was 3.6 Ω, and the occurrence rate of wiring cracks was 0%, and the overall judgment was NG.

<Comparative example 5>

As shown in Table 1, using the anisotropic conductive film to which the same conductive particles as in Comparative Example 3 were added, the TiO ₂ /Al-coated PET substrate and the IC were pressed under compression conditions of 190 ° C.-100 MPa-5 sec, and connected struct was obtained. The initial resistance value of the bonded structure was 0.7 Ω, the resistance value after the reliability test was 1.0 Ω, and the occurrence rate of wiring cracks was 25%, and the overall judgment was NG.

As in Comparative Example 1, when Ni-B was formed as the conductive layer and silica having a Mohs hardness of 7 was used as the insulating particle, the resistance after the reliability test was increased. Moreover, like the comparative example 2, when PET board|substrate was connected using the electroconductive particle of the comparative example 1, the resistance after a reliability test rose large. Moreover, like the comparative example 3, also when Ni-W-B was formed as a conductive layer and Mohs' Hardness 7 used silica as an insulating particle, the resistance after a reliability test rose. Moreover, like the comparative example 4, when PET board|substrate was connected using the electroconductive particle of the comparative example 2, the resistance after a reliability test rose largely. Moreover, when the pressure at the time of crimping|compression-bonding was made high like the comparative example 5 and PET board|substrate was connected, although the raise of the resistance after a reliability test could be suppressed, a crack has arisen.

On the other hand, as in Examples 1 to 4, when alumina having a Mohs hardness of 9 is used as the insulating particle, the increase in resistance after the reliability test can be suppressed without increasing the pressure at the time of compression, and the occurrence of cracks is prevented. Could. Also, as in Examples 2 and 4, low resistance was realized even in the connection of PET substrates. Further, as in Example 4, by forming Ni-W-B as the conductive layer, it was possible to realize further low resistance in the connection of the PET substrate. Since the hardness of insulating particle|grains is large, even if it did not raise the pressure at the time of crimping|compression-bonding, it is thought that these are because the oxide layer of the wiring surface was penetrated and the contact point of wiring and electroconductive particle increased.

10 resin core particles
20 insulating particles
30, 31, 32, 33, 34 conductive layer
40 conductive particles
41 resin core particles
42 insulating particles
50 first circuit member
51 terminal
52 oxide layer

Claims (18)

A resin core particle, a plurality of insulating particles attached to the surface of the resin core particle to form projections, and a conductive layer disposed on the surface of the resin core particle and the insulating particle, wherein the Mohs' Hardness of the insulating particle is It is larger than 7 and the compressive elastic modulus at the time of being compressed by 20% of the said resin core particle is 500-20000 N/mm<2> through the electrically-conductive material containing the electroconductive particle,
A method of manufacturing a connection structure for crimping a terminal of a first circuit member and a terminal of a second circuit member, which is a plastic substrate having an elastic modulus of 2000 MPa to 4100 MPa, comprising:
The manufacturing method of the bonded structure by which an oxide layer is formed on the terminal of the said 1st circuit member. The method of claim 1,
The manufacturing method of the bonded structure whose conductive layer of the said electroconductive particle is nickel or a nickel alloy. 3. The method of claim 1 or 2,
The manufacturing method of the bonded structure whose insulating particle|grains of the said electroconductive particle are at least 1 type or more in a zirconia, an alumina, a tungsten carbide, and a diamond. 3. The method of claim 1 or 2,
The average particle diameter of the insulating particle of the said electroconductive particle is 100-200 nm,
The number of projections formed on the surface of the resin core particles of the conductive particles is 1 to 500,
The manufacturing method of the bonded structure whose thickness of the conductive layer of the said electroconductive particle is 80-150 nm. 3. The method of claim 1 or 2,
The manufacturing method of the bonded structure formed by pressurizing from the said 2nd circuit member side. 3. The method of claim 1 or 2,
The manufacturing method of the bonded structure which crimps|bonds the terminal of the said 1st circuit member and the terminal of the said 2nd circuit member with the pressure of 10-80 MPa. 3. The method of claim 1 or 2,
The manufacturing method of the bonded structure by which _a TiO2 layer is formed on the terminal of the said 1st circuit member. A resin core particle, a plurality of insulating particles attached to the surface of the resin core particle to form a projection, and a conductive layer disposed on the surface of the resin core particle and the insulating particle, wherein the Mohs' Hardness of the insulating particle is By the electroconductive particle which is larger than 7 and whose compressive elastic modulus when 20% of the said resin core particle is compressed is 500-20000 N/mm<2>,
The terminal of the first circuit member, which is a plastic substrate having an elastic modulus of 2000 MPa to 4100 MPa, and the terminal of the second circuit member are connected,
A connection structure in which an oxide layer is formed on a terminal of the first circuit member. 9. The method of claim 8,
The bonded structure whose conductive layer of the said electroconductive particle is nickel or a nickel alloy. 10. The method according to claim 8 or 9,
The bonded structure in which the insulating particle of the said electroconductive particle is at least 1 type or more in a zirconia, an alumina, a tungsten carbide, and a diamond. 10. The method according to claim 8 or 9,
The average particle diameter of the insulating particle of the said electroconductive particle is 100-200 nm,
The number of projections formed on the surface of the resin core particles of the conductive particles is 1 to 500,
The bonded structure whose thickness of the conductive layer of the said electroconductive particle is 80-150 nm. 10. The method according to claim 8 or 9,
A connection structure in which a TiO ₂ layer is formed on a terminal of the first circuit member. A resin core particle, a plurality of insulating particles attached to the surface of the resin core particle to form a projection, and a conductive layer disposed on the surface of the resin core particle and the insulating particle, wherein the Mohs' Hardness of the insulating particle is It is larger than 7 and contains the conductive particles having a compressive elastic modulus of 500 to 20000 N/mm 2 when compressed by 20% of the resin core particles,
A conductive material for connecting a terminal of a first circuit member that is a plastic substrate having an elastic modulus of 2000 MPa to 4100 MPa and a terminal of a second circuit member,
The conductive material in which an oxide layer is formed on the terminal of the said 1st circuit member. 14. The method of claim 13,
The electrically-conductive material whose conductive layer of the said electroconductive particle is nickel or a nickel alloy. 14. The method of claim 13,
The electrically-conductive material whose insulating particle|grains of the said electroconductive particle are at least 1 type or more in a zirconia, an alumina, a tungsten carbide, and a diamond. 14. The method of claim 13,
The average particle diameter of the insulating particle of the said electroconductive particle is 100-200 nm,
The number of projections formed on the surface of the resin core particles of the conductive particles is 1 to 500,
The electrically-conductive material whose thickness of the conductive layer of the said electroconductive particle is 80-150 nm. 14. The method of claim 13,
A conductive material in which a TiO ₂ layer is formed on a terminal of the first circuit member. The conductive film in which the electrically-conductive material in any one of Claims 13-17 was formed in the film form.

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