JP2012248531A - Conductive particulate and anisotropic conductive material using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a conductive particulate which has a low initial connection resistance value when applied to an electrical connection, and also allows suppression of increase in the resistance value with time, thereby maintaining superior connection reliability over a long term.SOLUTION: The conductive particulate includes: a base material made of resin particles; and at least one conductive metal layer formed on a surface of the base material. A mean particle diameter of the resin particles is 12.5-50 μm, and a compressive deformation recovery rate thereof after applying a load of a compression load value 49 mN is 5-65%.

Description

  The present invention relates to conductive fine particles having a relatively large particle diameter, and particularly relates to conductive fine particles that can suppress an increase in resistance value over time and maintain good connection reliability over a long period of time.

  2. Description of the Related Art Conventionally, in assembling electronic devices, a connection method using an anisotropic conductive material has been adopted to make electrical connection between a large number of opposing electrodes and wirings. An anisotropic conductive material is a material in which conductive fine particles are mixed with a binder resin, for example, anisotropic conductive paste (ACP), anisotropic conductive film (ACF), anisotropic conductive ink, anisotropic conductive. There are sheets. Here, as the conductive fine particles used for the anisotropic conductive material, those obtained by coating the surfaces of the metal particles and the resin particles as the base material with a conductive metal layer are used.

  By the way, in recent years, electronic devices have been increasingly reduced in size and functionality. Along with this, electronic components mounted on electronic devices are becoming smaller and more densely mounted, and the connection resistance value is low and the resistance value is low from the viewpoint of reducing heat generation (Joule heat) due to connection resistance. A maintained anisotropic conductive connection is required.

  As the conductive fine particles used for anisotropic conductive connection, generally, a resin particle is used as a core material, and a conductive layer such as nickel is formed on the surface of the core material, because it is excellent in compressive deformability. Various particles having different particle diameters are used depending on the application. Furthermore, in order to obtain an anisotropic conductive material excellent in terms of connection stability, particles having high flexibility and a high recovery rate have been demanded.

  For example, for the purpose of providing conductive particles capable of reducing connection resistance and increasing connection reliability when electrodes are connected, resin particles made of a predetermined acrylic monomer and a conductive layer covering the resin particles and the surface thereof are used. The electroconductive particle which becomes is disclosed (patent document 1). Patent Document 1 discloses a resin particle having a compression deformation recovery rate of 80% or more as a preferred form of the resin particles, and in the examples, resin particles having an average particle diameter of about 5 μm and a compression deformation recovery rate of 80% or more.

  In addition, for the purpose of providing polymer particles with improved flexibility and recoverability after compression deformation, it has a predetermined composition, 10% compression modulus is 0.5 to 2.2 GPa, and recovery rate after compression deformation is A polymer particle of 70 to 100% has been proposed (Patent Document 2). In Patent Document 2, as one of the effects of the invention, when the average particle diameter is in the range of 10 to 200 μm and the CV value is in the range of 10% or less, for example, a liquid crystal display device spacer, an EL display device spacer, a touch panel spacer In addition, as a spacer for maintaining a uniform distance between substrates of various substrates, a core material of conductive particles, etc., it is described that flexibility and recoverability after compression deformation can be sufficiently exhibited (paragraph Further, in the examples, polymer particles having an average particle diameter of 39.4 μm and a compression deformation recovery rate of 88.8% are disclosed.

  Furthermore, the present invention provides a conductive fine particle and a connection structure that have flexibility and deformation recovery properties, relieve stress generated at a connection portion between electrodes of an electric circuit due to a temperature change or the like, and have high connection reliability. For the purpose of the above, a conductive fine particle using a base particle having a compression elastic modulus of 100 to 1000 MPa, a compression deformation recovery rate of 80 to 100% and a particle diameter of 50 μm or more when 10% of the particle diameter is displaced is proposed. (Patent Document 3). In the examples of Patent Document 3, the average particle size obtained by suspension polymerization using 50% by weight of 1,6-hexanediol diacrylate and 50% by weight of divinylbenzene was displaced by 10% of the particle size. A conductive fine particle is disclosed in which a conductive layer is formed on a substrate fine particle having a compression elastic modulus of 500 MPa and a compression deformation recovery rate of 95%.

JP 2010-159328 A JP 2010-90213 A JP 2005-294044 A

  However, when conductive fine particles based on resin particles having a high compression deformation recovery rate of, for example, 80% or more are used for electrical connection as in the past, the initial connection resistance value immediately after mounting is sufficiently low. However, the resistance value may increase over time, and connection reliability may not be maintained for a long time.

  Therefore, the present invention provides not only a low initial connection resistance value, but also an increase in resistance value over time when subjected to electrical connection, and conductivity that can maintain good connection reliability over a long period of time. An object is to provide fine particles and an anisotropic conductive material using the same.

  As a result of detailed investigations on the relationship between the compression elastic characteristics (particularly compression deformation recovery rate) and the stability of connection resistance over time, the present inventor has found that there is a particle size dependency between the recovery rate and the resistance stability over time. It was found that the range of the appropriate recovery rate for maintaining the resistance value stability with time varies depending on the particle diameter. In other words, when the particle diameter is small (eg, less than 12.5 μm) as in the case of conductive fine particles that are usually used for anisotropic conductive materials, the resistance stability over time can be improved by increasing the compression deformation recovery rate (eg, 65% or more). However, when the particle size is large, it has been found that, on the contrary, reducing the compression deformation recovery rate is important in terms of the stability of the resistance value with time.

That is, the conductive fine particles according to the present invention are conductive fine particles having a base material composed of resin particles and at least one conductive metal layer formed on the surface of the base material, and the average of the resin particles The particle diameter is 12.5 μm to 50 μm, and the compression deformation recovery rate after applying a compression load value of 49 mN is 5 to 65%. In the conductive particles of such present invention, the compression modulus when the diameter is displaced 20% of the resin particles (20% K value) is 1000 N / mm ² or more, it is preferable that 14000N / mm ² or less.
The anisotropic conductive material according to the present invention is characterized in that the conductive fine particles of the present invention are dispersed in a binder resin.

  According to the present invention, since the compression deformation recovery rate of the resin particles as the base material is controlled within an appropriate range set in accordance with the particle diameter, the initial connection resistance value when subjected to electrical connection In addition to being low, an increase in resistance value with time is also suppressed, and good connection reliability can be maintained over a long period of time. Since such conductive fine particles have a relatively large particle size, they can be suitably used for electrical connection in semiconductor mounting used in, for example, touch panels and LEDs.

  The conductive fine particles of the present invention are composed of resin particles as a base material and at least one conductive metal layer formed on the surface of the base material.

1. Resin particles (base material)
The average particle diameter of the resin particles is a number-based average dispersed particle diameter of 12.5 μm or more, preferably 13 μm or more, more preferably 15 μm or more, still more preferably 17 μm or more, 50 μm or less, preferably 45 μm or less. More preferably, it is 40 micrometers or less, More preferably, it is 35 micrometers or less. If the average particle diameter of the resin particles (base material) is within the above range, it can be suitably used for electrical connection of electrodes and wiring in semiconductor mounting used for touch panels, LEDs and the like.

The number-based variation coefficient (CV value) of the resin particles is preferably 10.0% or less, more preferably 8.0% or less, still more preferably 5.0% or less, and still more preferably. It is 4.0% or less, particularly preferably 3.0% or less. As described above, the resin particles having a small variation coefficient of the particle diameter not only have the same primary particle diameter, but also have a very high monodispersibility of the primary particle diameter. Therefore, by using such resin particles as a base material, conductive fine particles having a uniform particle diameter and suppressed aggregation can be obtained. The lower limit of the CV value of the resin particles is usually 0.5% or more. In the present invention, even if the coefficient of variation is controlled to a relatively low range as described above, the particle diameter is large, so the difference in particle diameter between the particles itself becomes large. As the difference in particle diameter increases, the resistance value after connection tends to increase with time only by reducing the CV value. Therefore, even when the CV value is reduced, it is important to set the compression deformation recovery rate to 65% or less as in the present invention.
The average particle diameter based on the number of resin particles and the coefficient of variation of the particle diameter in the present invention are values measured by a Coulter counter, and the measurement method will be described later in Examples.

It is important that the resin particles have a compression deformation recovery rate (sometimes referred to simply as “recovery rate” in the present specification) of 5 to 65% after applying a compression load value of 49 mN. As a result, moderate resilience is maintained, the resistance value at the initial stage of connection can be sufficiently reduced, and the increase in resistance value over time after connection can be efficiently suppressed. The compression deformation recovery rate is preferably 10% or more, more preferably 20% or more, and further preferably 25% or more. On the other hand, the upper limit is preferably 50% or less, more preferably 40% or less. When the recovery rate of the resin particles is less than 5%, when the conductive fine particles based on the resin particles are used for the anisotropic conductive material, the repulsive force in the connected state is too small, and the slight amount in the use environment is small. When the distance between connections varies due to a temperature change or the like, it cannot follow, and as a result, the resistance value increases. On the other hand, when the recovery rate of the resin particles exceeds 65%, when conductive fine particles based on the resin particles are used as the anisotropic conductive material, the connection resistance value gradually increases. The cause of this is not clear, but is considered as follows. That is, the particle diameter always varies, and even if the coefficient of variation is controlled to be small, resin particles having a large particle diameter (for example, an average particle diameter of 12.5 μm or more) are fine (for example, an average particle diameter of 12). Compared to resin particles (less than .5 μm), the difference in particle size itself is large. In this way, if the particle size difference is large and the resin particles have a large repulsive force such that the recovery rate exceeds 65%, the distance between connections gradually changes after connection, and an insufficiently connected part is likely to occur. It is thought that it will become.
In particular, when the recovery rate of the resin particles is 30% or more and 65% or less, the recovery rate is relatively high and the binder removal property at the time of mounting becomes high, so that the initial resistance value can be kept low. On the other hand, when the recovery rate of the resin particles is 5% or more and less than 30%, the initial resistance value is higher than particles having a recovery rate of 30% or more and 65% or less. Increase in resistance can be suppressed.

In the present invention, the compression deformation recovery rate is first constant in, for example, a compression test in which a load is applied in the center direction of particles using a known micro-compression tester (for example, “MCT-W500” manufactured by Shimadzu Corporation). The maximum load when the load is reduced to the minimum load at the same load load speed as the maximum load L1, and then the maximum load when the load is reduced to the minimum load at the same load removal speed as the above load load speed. Is a value calculated based on the following equation, with the amount of displacement between the first load and the minimum load being determined as the recovery displacement amount L2. Specifically, as described in the examples to be described later, the load load speed (unloading load speed) is about 2.23 mN / sec, the maximum load is about 49 mN, and the minimum load is about 0.49 mN. it can.
Compression deformation recovery rate (%) = (L2 / L1) × 100

The resin particles preferably have a compression elastic modulus (20% K value) of 1,000 N / mm ² or more and 14,000 N / mm ² or less when the diameter of the resin particles is displaced by 20%. If the 20% K value of the resin particles exceeds 14,000 N / mm ² , it is necessary to increase the pressure at the time of connection in order to increase the amount of deformation of the particles. There is a possibility that the resistance value at the initial stage of connection becomes high. On the other hand, if the 20% K value of the resin particles is less than 1,000 N / mm ² , the resistance of the binder at the time of connection is lowered and the resistance value at the initial stage of connection may be increased. By setting the 20% K value in the above-described range, a connection with a sufficiently low initial resistance is possible even with a low-voltage connection, and a good connection can be obtained even when a thin glass or resin film is used as a connected medium. be able to. The 20% K value of the resin particles is preferably 10,000 N / mm ² or less, more preferably 8,000 N / mm ² or less, further preferably 6,000 N / mm ² or less, and most preferably 4,000 N / mm ^2. Or less, preferably 1,500 N / mm ² or more, more preferably 2,000 N / mm ² or more.

  The 20% K value of the resin particles can be measured by a compression test using a known fine compression tester, for example, a known fine compression tester (for example, “MCT-W500” manufactured by Shimadzu Corporation). In a compression test in which a load is applied at room temperature at a load loading speed of 19.37 mN / sec at room temperature, the compression load (N) and the compression displacement when the particle is deformed until the particle diameter is displaced by 20% (Mm) can be measured and determined based on the following formula.

（ここで、Ｅ：圧縮弾性率（Ｎ／ｍｍ²）、Ｆ：圧縮荷重（Ｎ）、Ｓ：圧縮変位（ｍｍ）、Ｒ：粒子の半径（ｍｍ）である。）

(Here, E: compression elastic modulus (N / mm ² ), F: compression load (N), S: compression displacement (mm), R: radius of particle (mm))

  In the present invention, the 20% K value of the resin particles is an important index for estimating the influence in actual connection. This is because the resin particles in the present invention have an average particle size of 12.5 μm or more, but in such a large particle size, even if the coefficient of variation of the particle size, which is a general measure of particle size distribution, is small, The difference in particle size between particles increases. Therefore, when it is used for electrical connection, at least about 20% of deformation is required so that the influence of particle size distribution in the connected state is reduced. Therefore, in estimating the influence in actual connection, it is considered useful to see the state when the resin particles are deformed by 20%.

The resin particles also its compression modulus when the diameter was allowed to 10% displacement (10% K value) of 2000N / mm ² or more, that is 15000 N / mm ² or less, it is easy to achieve a low initial resistance value This is preferable. 10% K value of the resin particles, more preferably 3000N / mm ² or more, more preferably 3500 N / mm ² or more, more preferably 4000 N / mm ² or more, more preferably 10000 N / mm ² or less, more preferably 8000 N / mm ² or less. The 10% K value of the resin particles can be obtained in the same manner as the 20% K value described above.

  In the resin particles, the ratio of the 10% K value to the 20% K value (10% K value / 20% K value) is 1.5 or more in order to obtain conductive fine particles suitable for low-pressure connection. More preferably, it is 1.6 or more, More preferably, it is 1.7 or more. The upper limit of the ratio of the 10% K value to the 20% K value is not particularly limited, but is usually 3.0 or less, and preferably 2.5 or less.

In the compression test, the resin particles are also subjected to a compression test until 50% of the particle diameter when the particles are not destroyed even if the particles are deformed until the particles are broken or until the particle diameter is displaced by 50%. When the particle is displaced and the value of the compression elastic modulus (K value) at each displacement amount is plotted on the vertical axis and the displacement amount is plotted on the horizontal axis, the value at which the K value is minimized (K value minimal value) is 100 N / mm ² or more, preferably 2800N / mm ² or less. When the K value minimum value is within this range, it becomes easy to ensure a large contact area with respect to the connected body such as an electrode. K value minimum value of the resin particles is preferably 2600N / mm ² or less, more preferably 2400 N / mm ² or less, more preferably 2200N / mm ² or less, and most preferably less 2000N / mm ^2, preferably 500 N / mm ² or more, more preferably 1000 N / mm ² or more.
In addition, each value (K value) of the compression elastic modulus in each displacement amount performs the compression test similar to the 20% K value and the 10% K value described above, and measures the compression load (N) and the compression displacement (mm). It can be calculated from the result.

The resin particles also use a displacement amount (displacement amount with respect to the diameter at the K value minimum value) obtained when the K value minimum value is obtained as described above, and the following formula K Compression ratio (%) indicating minimum value = [average value of displacement with respect to diameter at minimum K value (μm) / number average particle diameter (μm)] × 100
The compression ratio (the ratio of the displacement amount to the particle diameter (%)) indicating the minimum value of K calculated by the formula (1) is 10% or more and 50% or less, which is a large contact with the connected body such as an electrode. This is preferable in that the area can be easily secured. The compression ratio showing the K value minimum value is more preferably 20% or more, further preferably 30% or more, more preferably 40% or less, and further preferably 35% or less.

  Hereinafter, the components of the resin particles will be described. First, the resin particles may be particles composed only of an organic material such as a vinyl polymer, or an organic material such as a material (a composite material or the like) including a vinyl polymer and a polysiloxane skeleton. The particle | grains comprised with an inorganic composite material may be sufficient. For example, a resin particle composed of a material containing a vinyl polymer has an organic skeleton formed by polymerizing vinyl groups, and is excellent in elastic deformation during pressure connection. On the other hand, resin particles made of a material containing a polysiloxane skeleton are excellent in contact pressure with respect to the connected body during pressure connection. Therefore, resin particles composed of a material in which a polysiloxane skeleton and a vinyl polymer are combined are excellent in elastic deformation and contact pressure, and the connection reliability of the obtained conductive fine particles is further improved.

  As the monomer component constituting the resin particles, a vinyl monomer may be used to form an organic skeleton, and a silane monomer may be used to form a polysiloxane skeleton. Here, vinyl monomers are classified into vinyl crosslinkable monomers and vinyl noncrosslinkable monomers, and silane monomers are silane crosslinkable monomers and silane noncrosslinkable monomers. Divided into masses.

  The vinyl-based crosslinkable monomer has a vinyl group and can form a crosslinked structure, and specifically, a monomer (monomer having two or more vinyl groups in one molecule). (1)), or a monomer having one vinyl group and a functional group other than a vinyl group in one molecule (such as a carboxyl group, a protonic hydrogen-containing group such as a hydroxy group, or a terminal functional group such as an alkoxy group). (Monomer (2)). However, in the case of the monomer (2), in order to form a crosslinked structure as a vinyl-based crosslinkable monomer, the reaction (bonding) of the carboxyl group, hydroxy group, alkoxy group, etc. of the monomer (2) The partner group must be present in the other monomer.

  In the present invention, the “vinyl group” means not only a carbon-carbon double bond but also a polymerizable carbon-like (meth) acryloyl group, allyl group, isopropenyl group, vinylphenyl group, isopropenylphenyl group. A substituent having a carbon double bond is also included. In the present specification, “(meth) acryloyl group”, “(meth) acrylate” and “(meth) acryl” are “acryloyl group and / or methacryloyl group”, “acrylate and / or methacrylate” and “acryl and "/ Or methacryl".

Examples of the monomer (1) among the vinyl-based crosslinkable monomers include, for example, allyl (meth) acrylates such as allyl (meth) acrylate; ethylene glycol di (meth) acrylate, 1,4-butane Diol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, 1,10-decanediol di (meth) acrylate, 1,3-butylene di (meth) ) Alkanediol di (meth) acrylate such as acrylate; diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, decaethylene glycol di (Meta) Acrelay , Pentadecaethylene glycol di (meth) acrylate, pentacontactor ethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, polytetramethylene glycol di (meth) acrylate, etc. Di (meth) acrylates such as alkylene glycol di (meth) acrylate; Tri (meth) acrylates such as trimethylolpropane tri (meth) acrylate; Tetra (meth) acrylates such as pentaerythritol tetra (meth) acrylate; Hexa (meth) acrylates such as pentaerythritol hexa (meth) acrylate; aromatic hydrocarbon crosslinking agents such as divinylbenzene, divinylnaphthalene, and derivatives thereof (preferably Properly styrene polyfunctional monomers such as divinylbenzene); N, N-divinyl aniline, divinyl ether, divinyl sulfide, hetero atom-containing crosslinking agents such as divinyl sulfonic acid; and the like. Among these, (meth) acrylates (polyfunctional (meth) acrylate) and styrene polyfunctional monomers having two or more (meth) acryloyl groups in one molecule are preferable, and polyfunctional (meth) acrylate is more preferable. . Among the polyfunctional (meth) acrylates, (meth) acrylates having two or more (meth) acryloyl groups in one molecule are preferable, and among them, two (meth) acryloyl groups in one molecule are preferable. The di (meth) acrylate is preferably an alkanediol di (meth) acrylate.
Among the styrenic polyfunctional monomers, monomers having two vinyl groups in one molecule such as divinylbenzene are preferable. A monomer (1) may be used independently and may use 2 or more types together.

  Examples of the monomer (2) among the vinyl-based crosslinkable monomers include, for example, monomers having a carboxyl group such as (meth) acrylic acid; 2-hydroxyethyl (meth) acrylate, 2- Monomers having hydroxy groups such as hydroxy group-containing (meth) acrylates such as hydroxypropyl (meth) acrylate and 2-hydroxybutyl (meth) acrylate, hydroxy group-containing styrenes such as p-hydroxystyrene; 2-methoxy A single group having an alkoxy group such as an alkoxy group-containing (meth) acrylate such as ethyl (meth) acrylate, 3-methoxybutyl (meth) acrylate, 2-butoxyethyl (meth) acrylate, or an alkoxystyrene such as p-methoxystyrene. And the like. A monomer (2) may be used independently and may use 2 or more types together.

The vinyl non-crosslinkable monomer is a monomer having one vinyl group in one molecule (monomer (3)) or other than the vinyl group possessed by the monomer (2). The monomer (2) when the other monomer which has a group which reacts with a functional group does not exist in a monomer component is mentioned.
Examples of the monomer (3) among the vinyl non-crosslinkable monomers include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, and n-butyl (meth) acrylate. , Isobutyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate, stearyl Alkyl (meth) acrylates such as (meth) acrylate and 2-ethylhexyl (meth) acrylate; cyclopropyl (meth) acrylate, cyclopentyl (meth) acrylate, cyclohexyl (meth) acrylate, cyclooctyl (meth) acrylate Cycloalkyl (meth) acrylates such as rate, cycloundecyl (meth) acrylate, cyclododecyl (meth) acrylate, isobornyl (meth) acrylate, 4-t-butylcyclohexyl (meth) acrylate; phenyl (meth) acrylate, benzyl Aromatic ring-containing (meth) acrylates such as (meth) acrylate, tolyl (meth) acrylate, phenethyl (meth) acrylate; styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p Styrene monofunctional monomers such as alkyl styrenes such as -t-butylstyrene, halogen group-containing styrenes such as o-chlorostyrene, m-chlorostyrene, and p-chlorostyrene; Among these, it is preferable to use a methacrylate monofunctional monomer, and methyl methacrylate is more preferable. A monomer (3) may be used independently and may use 2 or more types together.

  The vinyl polymer preferably includes the vinyl crosslinkable monomer (1) as a constituent component. Among them, the vinyl noncrosslinkable monomer (3) and the vinyl crosslinkable monomer are preferable. The aspect containing (1) is preferable. Specifically, an embodiment containing a monomer having two or more (meth) acryloyl groups in one molecule as a constituent component is preferable, and a single component having one (meth) acryloyl group in one molecule is preferable. An embodiment including a monomer and a monomer having two or more (meth) acryloyl groups in one molecule is preferable.

  The polysiloxane skeleton is formed by hydrolyzing a silane monomer and generating a siloxane bond by a condensation reaction. In particular, when a silane crosslinkable monomer is used as a silane monomer, a crosslinked structure is formed. Can do. Examples of the crosslinked structure formed by the silane-based crosslinking monomer include those that crosslink an organic polymer skeleton (for example, a vinyl polymer skeleton) and an organic polymer skeleton (first form); a polysiloxane skeleton; One that crosslinks a polysiloxane skeleton (second form); one that crosslinks an organic polymer skeleton and a polysiloxane skeleton (third form).

  Examples of the silane-based crosslinkable monomer that can form the first form include dimethyldivinylsilane, methyltrivinylsilane, and tetravinylsilane. Examples of the silane crosslinkable monomer that can form the second form include tetrafunctional silane monomers such as tetramethoxysilane, tetraethoxysilane, tetraisopropoxysilane, and tetrabutoxysilane; methyltrimethoxy Examples thereof include trifunctional silane monomers such as silane, methyltriethoxysilane, ethyltrimethoxysilane, and ethyltriethoxysilane. Examples of silane-based crosslinkable monomers that can form the third form include 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, and 3-methacrylic monomer. Having a (meth) acryloyl group such as loxypropylmethyldimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-acryloxypropyltriethoxysilane, 3-methacryloxyethoxypropyltrimethoxysilane; vinyltrimethoxysilane, Those having a vinyl group such as vinyltriethoxysilane and p-styryltrimethoxysilane; 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 2- (3,4-epoxycyclohexyl) Those having an epoxy group such as trimethoxysilane; 3-aminopropyltrimethoxysilane, those having an amino group such as 3-aminopropyltriethoxysilane; and the like. These silane crosslinking monomers may be used alone or in combination of two or more.

Examples of the silane-based non-crosslinkable monomer include bifunctional silane-based monomers such as dimethyldimethoxysilane and dialkylsilane such as dimethyldiethoxysilane; and trialkylsilanes such as trimethylmethoxysilane and trimethylethoxysilane. And monofunctional silane-based monomers. These silane non-crosslinkable monomers may be used alone or in combination of two or more.
In particular, the polysiloxane skeleton is preferably a skeleton derived from a polymerizable polysiloxane having a radical-polymerizable carbon-carbon double bond (for example, a vinyl group such as a (meth) acryloyl group). That is, the polysiloxane skeleton has, as a constituent component, a silane-based crosslinkable monomer (preferably having a (meth) acryloyl group, more preferably 3-methacryloxy) capable of forming the crosslinked structure of the third form. A polysiloxane skeleton formed by hydrolysis and condensation of propyltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, and vinyltrimethoxysilane) is preferable.

  In addition to the organic materials and organic-inorganic composite materials described above, the resin particles include, for example, polyolefin-based vinyl polymers such as polyethylene, polypropylene, polyvinyl chloride, polytetrafluoroethylene, polyisobutylene, and polybutadiene; polyethylene terephthalate, Polyester such as polyethylene naphthalate; polycarbonate; polyamide; polyimide; phenol formaldehyde resin; melamine formaldehyde resin; melamine benzoguanamine formaldehyde resin; urea formaldehyde resin;

In order to control the recovery rate of the resin particles to be in the above-described range, for example, the monomer component constituting the resin particles is the above-described crosslinkable monomer (100% by mass) in the total amount of monomer components (100% by mass). The vinyl-based crosslinkable monomer and the silane-based crosslinkable monomer) are contained in an amount of 5% by mass to 60% by mass, and a monomer having no aromatic ring in 100% by mass of the total amount of monomer components. It is preferable to contain 5 mass% or more. The ratio of the crosslinkable monomer to the total amount of the monomer components of 100% by mass is more preferably 10% by mass or more, further preferably 15% by mass or more, and more preferably 55% by mass or less. Preferably it is 48 mass% or less, More preferably, it is 42 mass% or less. The ratio of the monomer having no aromatic ring to the total amount of the monomer components of 100% by mass is more preferably 10% by mass or more. When the monomer having no aromatic ring is less than 5% by mass (in other words, the monomer having an aromatic ring accounts for 95% by mass or more), the ratio of 10% K value / 20% K value is low. Therefore, there is a possibility that the contact area cannot be increased effectively.
The monomer having no aromatic ring may be a vinyl monomer or a silane monomer as long as it does not have an aromatic ring among the monomer components described above. May be. The monomer having no aromatic ring may be crosslinkable or non-crosslinkable, but is preferably crosslinkable.

Furthermore, in order to reliably control the compression deformation recovery rate of the resin particles within the above-described range, as the crosslinkable monomer, the following specific crosslinkable monomer (a) or the following specific crosslinkable monomer ( It is preferable that it contains at least one of b) (hereinafter sometimes simply referred to as “specific crosslinking monomer”).
Specific crosslinkable monomer (a): It has two vinyl groups in one molecule, and 14 or less atoms are connected between carbon-carbon double bonds (C = C) of both vinyl groups. A vinyl-based crosslinkable monomer in which a chain unit having a main chain portion is interposed.
Specific cross-linkable monomer (b): one molecule having one vinyl group and a silicon atom to which two condensable groups are bonded, and a carbon-carbon double bond (C = C) and a silane-based crosslinkable monomer in which a chain unit having a main chain part in which 14 or less atoms are connected is interposed between silicon atoms (Si).

Such a specific crosslinkable monomer has 14 or less atoms between the crosslinking points such as vinyl groups (also referred to as the number of atoms between the crosslinking points). If it exceeds 14, the resin particles tend to be too soft and the 20% K value tends to be too small. In the specific crosslinkable monomer, the number of atoms between crosslink points (that is, the number of atoms constituting the main chain part) is preferably 12 or less, and the lower limit thereof is preferably 4 or more, and 6 or more. Is more preferable. Note that the number of atoms constituting the main chain portion does not count the carbon atom of the carbon-carbon double bond (C = C) itself and the silicon atom itself.
In addition, other branched chains may be bonded to the main chain portion in which 14 or less atoms are connected (in other words, no ring is formed). Preferably, the main chain portion is a carbon atom and / Alternatively, the oxygen atoms are connected to each other.

  As the specific crosslinkable monomer (a), di (meth) acrylates exemplified as the monomer (1) among the vinyl-based crosslinkable monomers described above are preferable, and among them, alkanediol di ( (Meth) acrylate (for example, ethylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, 1,10-decanediol di (meth) acrylate, 1,3-butylene di (meth) acrylate, etc.) and polyalkylene glycol di (meth) acrylate (for example, diethylene glycol di (meth) acrylate, triethylene glycol di (meth)) Acrylate, tetraethylene glycol di (meth) acrylate, Polypropylene glycol di (meth) acrylate) are preferable, alkanediol di (meth) acrylate. Preferable specific examples include ethylene glycol di (meth) acrylate having 6 inter-crosslinking atoms and 1,10-decanediol di (meth) acrylate having 14 inter-crosslinking atoms. .

  As the specific crosslinkable monomer (b), 3-methacryloxypropylmethyldimethoxy exemplified as the silane crosslinkable monomer capable of forming the third form among the silane crosslinkable monomers described above. Preferable examples include 3-methacryloxypropylalkyldialkoxysilane such as silane and 3-methacryloxypropylmethyldiethoxysilane.

  Therefore, as a preferable form of the monomer component constituting the resin particle, the crosslinkable monomer is contained in an amount of 5% by mass or more and 60% by mass or less in the total amount of the monomer component of 100% by mass. Includes the specific crosslinkable monomer (a) and / or the specific crosslinkable monomer (b) as an essential component, and at least all of the monomer components are not monomers having an aromatic ring, Even if the monomer which has an aromatic ring is contained, it is a form which is less than 95 mass% in 100 mass% of monomer component total amount.

Further, when the resin particles have a polysiloxane skeleton derived from inorganic particles (organic-inorganic composite material), in order to reliably control the compression deformation recovery rate of the resin particles within the above range, silicon in the resin particles is used. The content is preferably 20% by mass or less when expressed in terms of Si relative to 100% by mass of the resin particles. More preferably, it is 15 mass% or less, More preferably, it is 10 mass% or less, More preferably, it is 6 mass% or less, Most preferably, it is 3 mass% or less. If the silicon content exceeds 20% by mass, the recovery rate of the resin particles becomes too high, and the connection reliability may be lowered. Incidentally, the silicon content, the resin particles were calculated mass corresponding in an oxidizing atmosphere such as air, from the ash mass when fired at 1000 ° C. (which is referred to as SiO ₂ amount) in Si content, the Si It can be determined by dividing the amount by the mass of the resin particles subjected to the firing treatment. The mass corresponding to the Si content can be calculated from the ash mass by multiplying the ash mass by 0.4672 (Si atomic weight / SiO ₂ formula weight).

  The shape of the resin particles (base material) is not particularly limited, and may be any of a spherical shape, a spheroid shape, a confetti shape, a thin plate shape, a needle shape, an eyebrow shape, etc., and a spherical shape is preferable. A true spherical shape is particularly preferable.

2. Conductive fine particles In the conductive fine particles of the present invention, at least one conductive metal layer is formed on the surface of the substrate (resin particles). The metal constituting the conductive metal layer is not particularly limited. For example, gold, silver, copper, platinum, iron, lead, aluminum, chromium, palladium, nickel, rhodium, ruthenium, antimony, bismuth, germanium, tin, cobalt Indium, nickel-phosphorous, nickel-boron and other metals and metal compounds, and alloys thereof. Among these, gold, nickel, palladium, silver, copper, and tin are preferable because they become conductive fine particles having excellent conductivity. Further, in terms of inexpensiveness, nickel, nickel alloy (Ni-Au, Ni-Pd, Ni-Pd-Au, Ni-Ag, Ni-P, Ni-B, Ni-Zn, Ni-Sn, Ni-W, Ni—Co, Ni—W, Ni—Ti); copper, copper alloy (Cu and Fe, Co, Ni, Zn, Sn, In, Ga, Tl, Zr, W, Mo, Rh, Ru, Ir, Ag, Alloy with at least one metal element selected from the group consisting of Au, Bi, Al, Mn, Mg, P, B, preferably an alloy with Ag, Ni, Sn, Zn); Silver, silver alloy (Ag And Fe, Co, Ni, Zn, Sn, In, Ga, Tl, Zr, W, Mo, Rh, Ru, Ir, Au, Bi, Al, Mn, Mg, P, B Alloy with one metal element, preferably Ag-Ni, Ag-Sn, Ag-Z ); Tin, tin alloy (for example, Sn—Ag, Sn—Cu, Sn—Cu—Ag, Sn—Zn, Sn—Sb, Sn—Bi—Ag, Sn—Bi—In, Sn—Au, Sn—Pb, etc.) Etc.) are preferred. Of these, nickel and nickel alloys are preferred. The conductive metal layer may be a single layer or multiple layers. In the case of multiple layers, for example, a combination of nickel-gold, nickel-palladium, nickel-palladium-gold, nickel-silver, etc. Is preferred.

The thickness of the conductive metal layer is preferably 0.010 μm or more, more preferably 0.030 μm or more, still more preferably 0.050 μm or more, preferably 0.30 μm or less, more preferably 0.25 μm or less, More preferably, it is 0.20 micrometer or less, More preferably, it is 0.15 micrometer or less. In the conductive fine particles of the present invention in which the resin particles as the base material have a fine particle diameter, when the conductive metal layer has a thickness within the above range, the conductive fine particles are used as an anisotropic conductive material. Stable electrical connection can be maintained.
The conductive metal layer only needs to cover at least a part of the surface of the resin particles, but the surface of the conductive metal layer has no substantial cracks or conductive metal layer. Is preferably absent. Here, “substantially cracked or a surface on which no conductive metal layer is formed” means that when the surface of any 10,000 conductive fine particles is observed using an electron microscope (magnification 1000 times), It means that the crack of the conductive metal layer and the exposure on the surface of the resin particles are not substantially visually observed.

The number average particle diameter of the conductive fine particles of the present invention is preferably 13.5 μm or more, more preferably 14 μm or more, further preferably 15 μm or more, particularly preferably 16 μm or more, preferably 51 μm or less, more preferably 46 μm or less. More preferably, it is 41 μm or less, and more preferably 36 μm or less. If the number average particle diameter is within this range, it can be suitably used for electrical connection of miniaturized and narrowed electrodes and wirings.
The number average particle size of the conductive fine particles was determined using a flow type particle image analyzer (“FPIA (registered trademark) -3000” manufactured by Sysmex Corporation), and was based on the number average particle size of 3000 particles. Is preferably adopted.

  The conductive fine particles of the present invention preferably have a compression deformation recovery rate of 5 to 65% after applying a compression load value of 49 mN. As a result, moderate resilience is maintained, the resistance value at the initial stage of connection can be sufficiently reduced, and the increase in resistance value over time after connection can be efficiently suppressed. The compression deformation recovery rate is preferably 10% or more, more preferably 20% or more, and further preferably 30% or more. On the other hand, the upper limit is preferably 50% or less, more preferably 40% or less.

Conductive fine particles of the present invention, the compression modulus when the diameter was 20% displacement (20% K value) of 1,000 N / mm ² or more, it is preferable that the 15,000N / mm ² or less. If the 20% K value of the conductive fine particles exceeds 15,000 N / mm ² , it is necessary to increase the pressure at the time of connection in order to increase the amount of deformation of the particles. The resistance value at the initial stage of connection tends to be high. On the other hand, if the 20% K value of the resin particles is less than 1,000 N / mm ² , the resistance of the binder at the time of connection is lowered and the resistance value at the initial stage of connection may be increased. By setting the 20% K value in the above-described range, it is possible to connect with a low initial resistance value even with a low-voltage connection, and it is possible to connect with a low resistance even to a connected medium such as a thin glass or resin film. Become.

The conductive fine particles of the present invention have a compressive modulus (20% K value of the conductive fine particles) when the diameter is displaced by 20%, preferably 11,000 N / mm ² or less, more preferably 9,000 N / mm ² or less, more preferably 7,000 N / mm ² or less, most preferably 5,000 N / mm ² or less, preferably 1,500 N / mm ² or more, more preferably 2,000 N / mm ² or more. .
Further, the conductive fine particles of the present invention have a ratio of the compressive modulus (10% K value of the conductive fine particles) when the diameter is displaced by 10% to the 20% K value of the conductive fine particles described above (conductive fine particles). 10% K value / 20% K value of conductive fine particles) is preferably 1.5 or more. By being 1.5 or more, it becomes the electroconductive fine particle suitable for a low voltage | pressure connection, and also the effect that the contact area with respect to a to-be-connected body can be enlarged effectively is acquired. The ratio is more preferably 1.6 or more, and even more preferably 1.7 or more, and the upper limit is not particularly limited, but is usually 3.0 or less, and preferably 2.5 or less.

  The compression deformation recovery rate, 20% K value, and 10% K value of the conductive fine particles can be measured in the same manner as the resin particle recovery rate, 20% K value, and 10% K value.

The conductive fine particles of the present invention may have an insulating resin layer on at least a part of the surface. That is, the aspect which provided the insulating resin layer further on the surface of the said electroconductive metal layer may be sufficient. When the insulating resin layer is further laminated on the conductive metal layer on the surface in this way, it is possible to prevent the lateral conduction that is likely to occur when a high-density circuit is formed or when a terminal is connected.
The insulating resin layer is not particularly limited as long as the insulating property between the particles of the conductive fine particles can be secured, and the insulating resin layer can be easily collapsed or peeled off by a certain pressure and / or heating. For example, polyolefins such as polyethylene; (meth) acrylate polymers and copolymers such as polymethyl (meth) acrylate; thermoplastic resins such as polystyrene; and cross-linked products thereof; epoxy resins, phenol resins, amino resins (melamine resins, etc.) And the like; and water-soluble resins such as polyvinyl alcohol and mixtures thereof. However, when the insulating resin layer is too hard compared to the base particle, the base particle itself may be destroyed before the insulating resin layer is destroyed. Therefore, it is preferable to use an uncrosslinked or relatively low degree of crosslinking resin for the insulating resin layer.

  The insulating resin layer may be a single layer or a plurality of layers. For example, a single or a plurality of film-like layers may be formed, or a layer in which particles having insulating, granular, spherical, lump, scale or other shapes are attached to the surface of the conductive metal layer. Further, it may be a layer formed by chemically modifying the surface of the conductive metal layer, or a combination thereof. The thickness of the insulating resin layer is preferably 0.01 μm to 1 μm, more preferably 0.02 μm to 0.5 μm, still more preferably 0.03 μm to 0.4 μm. When the thickness of the insulating resin layer is within the above range, the electrical insulation between the particles becomes good while maintaining the conduction characteristics by the conductive particles.

3. Manufacturing method First, the manufacturing method of the said resin particle used as a base material is demonstrated.
The method for producing the resin particles is not particularly limited as long as the above-described monomer component is polymerized, and is not particularly limited, but emulsion polymerization, suspension polymerization, dispersion polymerization, seed polymerization, sol-gel seed polymerization method, etc. Is mentioned. In order to set the particle diameter of the resin particles within the predetermined range described above, for example, a method of classifying the resin particles after being synthesized by a seed polymerization method is preferably employed. By employing a seed polymerization method for the synthesis of resin particles, resin particles having a small particle size distribution can be obtained. Furthermore, the average particle diameter can be adjusted to a desired range by classifying the synthesized resin particles and removing coarse particles.

The seed polymerization method is a method of obtaining resin particles through a seed particle preparation step, an absorption step in which the seed particle absorbs the monomer component, and a polymerization step in which the monomer component absorbed in the seed particle is polymerized. The method and conditions in each step are not particularly limited as long as a known seed polymerization method is appropriately employed. For example, the following methods are preferably employed. The specific crosslinkable monomer ((a), (b)), which is a suitable monomer component for constituting the resin particle, is absorbed as a component constituting the seed particle and / or in the seed particle. The monomer component to be used is preferably used in the preferred composition range described above.
In the seed particle preparation step, when synthesizing resin particles composed only of an organic material, the seed particles are prepared by a method such as soap-free emulsion polymerization or dispersion polymerization using the vinyl monomer. Good. In this case, it is preferable to use a styrene monofunctional monomer such as styrene as the vinyl monomer. On the other hand, when synthesizing particles composed of an organic material and a material having a polysiloxane skeleton, a solvent containing water (for example, alcohols, ketones, esters, ( The seed particles (polysiloxane particles) may be prepared by hydrolysis and condensation polymerization in a mixed solvent of an organic solvent such as cyclo) paraffins and aromatic hydrocarbons and water. In this case, it is preferable to use a silane crosslinkable monomer having a radical polymerizable group as the silane monomer to form polymerizable polysiloxane particles. Moreover, it is preferable to use the specific crosslinkable monomer (b) mentioned above as a silane monomer. In the hydrolysis and polycondensation, basic catalysts such as ammonia, urea, ethanolamine, tetramethylammonium hydroxide, alkali metal hydroxide, and alkaline earth metal hydroxide can be preferably used as the catalyst. If necessary, an anionic, cationic or nonionic surfactant or a polymer dispersant such as polyvinyl alcohol or polyvinylpyrrolidone can be used in combination.

  The method for absorbing the monomer component in the seed particles in the absorption step is not particularly limited. For example, the monomer component may be added to a seed particle dispersion in which the seed particles are previously dispersed in a solvent. The seed particles may be added to the solvent containing the monomer component. In particular, in the former method, the reaction solution obtained by polymerization, hydrolysis, or condensation may be used as a seed particle dispersion as it is. From the viewpoint of simplification and productivity. The monomer component may be added alone, or may be added as a solution dissolved in a solvent, but in order to efficiently absorb the seed particles, water or an aqueous medium ( For example, it is preferable to add as an emulsified liquid by emulsifying and dispersing in a water-soluble organic solvent such as alcohols, ketones and esters, or a mixed solvent of these with water). It is preferable to use at least the above-mentioned specific crosslinkable monomer (a) as a monomer component to be absorbed.

When emulsifying and dispersing the monomer component with an emulsifier, examples of the emulsifier include anionic surfactants, polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene fatty acid esters, sorbitan fatty acid esters. , Dispersion state of seed particles after nonionic surfactant such as polyoxysorbitan fatty acid ester, polyoxyethylene alkylamine, glycerin fatty acid ester, oxyethylene-oxypropylene block polymer absorbs monomer component Is preferably used in that it can be stabilized. In addition, the amount of water or aqueous medium used for emulsification and dispersion is usually 0.3 to 10 times the mass of the monomer component.
In the absorption process, for determining whether the monomer component has been absorbed by the seed particles, for example, before adding the monomer component and after completion of the absorption step, observe the particles with a microscope and absorb the monomer component. It can be easily determined by confirming that the particle size is increased. In addition, in order to obtain the resin particle in this invention, although the absorption rate shown by a following formula is not specifically limited, It is preferable that it is 1.0 to 50 times.
Absorption magnification = (total mass of monomer components to be absorbed) / (mass of seed particles)

  The polymerization method employed in the polymerization step is not particularly limited, and for example, a known method such as a method using a radical polymerization initiator (for example, a peroxide-based initiator, an azo-based initiator, etc.) can be used. The reaction temperature at the time of performing radical polymerization is preferably 40 ° C or higher, more preferably 50 ° C or higher, preferably 100 ° C or lower, more preferably 80 ° C or lower. If the reaction temperature is too low, the degree of polymerization does not increase sufficiently and the mechanical properties of the composite particles tend to be insufficient. On the other hand, if the reaction temperature is too high, aggregation between particles tends to occur during the polymerization. There is. The reaction time for performing radical polymerization may be appropriately changed according to the type of polymerization initiator to be used, but is usually preferably 5 minutes or more, more preferably 10 minutes or more, and preferably 600 minutes or less. More preferably, it is 300 minutes or less. If the reaction time is too short, the degree of polymerization may not be sufficiently increased, and if the reaction time is too long, aggregation tends to occur between particles. In such a polymerization step, when the seed particles are polymerizable polysiloxane particles, in the polymerization step, the absorbed monomer component and the radical polymerizable group of the polymerizable polysiloxane skeleton are polymerized, A polysiloxane skeleton and a vinyl polymer are combined.

  The resin particles synthesized as described above are preferably subjected to classification so as to have a predetermined particle diameter. The classification method is not particularly limited, for example, sieving with an electroforming sieve, etc .; filtration using a filter such as a membrane filter, a pleat filter, a ceramic membrane filter, etc .; a known apparatus for classification by the interaction of mass difference and fluid resistance difference ( Gravity classifier based on the principle of gravity difference such as particle fall velocity, (half) free vortex centrifugal classification based on the balance of centrifugal force and air drag by free vortex or semi-free vortex, rotating classification blade (rotor) Classification using a centrifugal classification with rotating blades based on the balance between the centrifugal force generated by the generated rotating flow and the drag force caused by air. Among these, classification using an electric sieve is preferable from the viewpoint of classification accuracy and productivity.

After the synthesis, the resin particles classified as necessary are usually dried and optionally subjected to firing. Although drying temperature is not specifically limited, Usually, it is the range of 50 to 250 degreeC.
As described above, the resin particles are prepared so as to satisfy the above-described ranges with respect to the average particle size, the variation coefficient of the particle size, and the like.

Next, conductive fine particles are obtained by forming a conductive metal layer on the resin particles (base material) obtained as described above and further forming an insulating resin layer as necessary.
The formation method of the conductive metal layer and the formation method of the insulating resin layer are not particularly limited. For example, the conductive metal layer is plated on the substrate surface by an electroless plating method, an electrolytic plating method, or the like; Or a method of forming a conductive metal layer by a physical vapor deposition method such as vacuum vapor deposition, ion plating, or ion sputtering; Among these, the electroless plating method is particularly preferable in that a conductive metal layer can be easily formed without requiring a large-scale apparatus.

4). Anisotropic conductive material The anisotropic conductive material of the present invention comprises the conductive fine particles of the present invention dispersed in a binder resin. The form of the anisotropic conductive material is not particularly limited, and examples thereof include various forms such as an anisotropic conductive film, an anisotropic conductive paste, an anisotropic conductive adhesive, and an anisotropic conductive ink. By providing these anisotropic conductive materials between opposing substrates or between electrode terminals, good electrical connection can be achieved. The anisotropic conductive material using the conductive fine particles of the present invention includes a conductive material for a liquid crystal display element (conductive spacer and composition thereof). Suitable applications of the anisotropic conductive material include touch panel input, LED, and the like, and particularly suitable for LED mounting.

The binder resin is not particularly limited as long as it is an insulating resin. For example, thermoplastic resins such as acrylic resins, ethylene-vinyl acetate resins, styrene-butadiene block copolymers; monomers and oligomers having a glycidyl group; Examples thereof include a curable resin composition that is cured by a reaction with a curing agent such as isocyanate; a curable resin composition that is cured by light or heat;
The anisotropic conductive material of the present invention can be obtained by dispersing the conductive fine particles of the present invention in the binder resin to obtain a desired form. For example, the binder resin and the conductive fine particles are separately provided. You may connect by making electroconductive fine particles exist with a binder resin between the base material to be used and connecting between electrode terminals.

  In the anisotropic conductive material of the present invention, the content of the conductive fine particles may be appropriately determined according to the use. For example, the volume of the anisotropic conductive material is preferably 1% by volume or more, more preferably Is 2% by volume or more, more preferably 5% by volume or more, preferably 50% by volume or less, more preferably 30% by volume or less, and still more preferably 20% by volume or less. If the content of the conductive fine particles is too small, it may be difficult to obtain sufficient electrical continuity. On the other hand, if the content of the conductive fine particles is too large, the conductive fine particles are in contact with each other, and anisotropy is caused. The function as a conductive material may be difficult to be exhibited.

  About the film thickness in the anisotropic conductive material of the present invention, the coating thickness of the paste or adhesive, the printed film thickness, etc., the particle diameter of the conductive fine particles of the present invention to be used and the specifications of the electrode to be connected In consideration of the above, it is preferable to appropriately set so that the conductive fine particles are sandwiched between the electrodes to be connected and the gap between the bonding substrates on which the electrodes to be connected are formed is sufficiently filled with the binder resin layer. .

  The present invention will be described more specifically with reference to the following examples. However, the present invention is not limited to the following examples, and may be appropriately modified and implemented within a range that can meet the purpose described above and below. All of which are within the scope of the present invention. In the following, “part” means “part by mass” and “%” means “mass%” unless otherwise specified.

1. Physical property measurement method Various physical properties were measured by the following methods.
<Average particle diameter and coefficient of variation (CV value) of seed particles and resin particles>
In the case of resin particles, 0.1% of resin particles are added to 1% of polyoxyethylene alkyl ether sulfate ammonium salt (“Hitenol (registered trademark) N-08” manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) as an emulsifier. A dispersion obtained by adding 20 parts of an aqueous solution and ultrasonically dispersing for 10 minutes is used as a measurement sample. In the case of seed particles, a dispersion obtained by hydrolysis and condensation reaction is added to a polyoxyethylene alkyl ether sulfate ammonium salt ( Using a sample diluted with a 1% aqueous solution of “Hitenol (registered trademark) N-08” manufactured by Daiichi Kogyo Seiyaku Co., Ltd. as a measurement sample, using a particle size distribution analyzer (“Coulter Multisizer Type III” manufactured by Beckman Coulter, Inc.) The particle diameter (μm) of 30000 particles was measured, and the number-based average dispersed particle diameter was determined. For the resin particles, the standard deviation of the particle diameter on the basis of the number is obtained together with the average dispersed particle diameter, and the coefficient of variation (CV value) of the particle diameter is calculated according to the following formula.
Particle variation coefficient (%) = 100 × (standard deviation of particle diameter / average dispersed particle diameter)

<Film thickness of conductive metal layer>
Using a flow type particle image analyzer (“FPIA (registered trademark) -3000” manufactured by Sysmex Corporation), the number average particle diameter X (μm) of 3000 base particles (resin particles) and the number of 3000 conductive fine particles The average particle size Y (μm) was measured. The measurement was performed by adding 17.5 parts of a 1.4% aqueous solution of polyoxyethylene oleyl ether (“Emulgen (registered trademark) 430” manufactured by Kao Corporation) as an emulsifier to 0.25 parts of the particles, After dispersing for 10 minutes. And the film thickness of the electroconductive metal layer was computed according to the following formula.
Conductive metal layer thickness (μm) = (Y−X) / 2

<10% K value and 20% K value of resin particles>
Using a micro-compression tester (“MCT-W500” manufactured by Shimadzu Corporation), a circular flat plate indenter with a diameter of 50 μm is used for one particle dispersed on a sample stage (material: SKS flat plate) at room temperature (25 ° C.). Using (material: diamond) and applying a load at a constant load speed (19.37 mN / sec) toward the center of the particle in the “standard surface detection” mode, and the compression displacement becomes 10% of the particle diameter The load value (mN) and the displacement amount (μm) at that time, and the load (mN) when the compression displacement becomes 20% of the particle diameter and the displacement amount (μm) at that time were measured. In addition, the measurement was performed on 10 different particles for each sample, and the average value was used as the measurement value. Then, the obtained load value (mN) is converted into a compressive load (N), the obtained displacement amount (μm) is converted into a compressive displacement (mm), and the average particle diameter (μm) of the resin particles is used to calculate the particle size. The radius (mm) was calculated and calculated based on the following formula using these.

（ここで、Ｅ：圧縮弾性率（Ｎ／ｍｍ²）、Ｆ：圧縮荷重（Ｎ）、Ｓ：圧縮変位（ｍｍ）、Ｒ：粒子の半径（ｍｍ）である。）
また、得られた１０％Ｋ値、２０％Ｋ値より、比率（１０％Ｋ値／２０％Ｋ値）を算出した。

(Here, E: compression elastic modulus (N / mm ² ), F: compression load (N), S: compression displacement (mm), R: radius of particle (mm))
Further, a ratio (10% K value / 20% K value) was calculated from the obtained 10% K value and 20% K value.

<Compression ratio indicating K value minimum value and K value minimum value of resin particles>
In a compression test similar to the measurement of 10% K value and 20% K value of resin particles, when the particles are not broken even if they are deformed until the particles are broken or until the diameter of the particles is displaced by 50%. The particles are displaced until the compression displacement reaches 50% of the particle diameter, and the K value is minimal when the compression modulus value (K value) at each displacement amount is plotted on the vertical axis and the displacement amount is plotted on the horizontal axis. (Ie, K value minimum value; N / mm ² ) and the amount of displacement when showing the K value minimum value (that is, the amount of displacement relative to the diameter at the K value minimum value; μm). The measurement was performed on 10 different particles for each sample, and the average value of the K value minimum value and the displacement amount with respect to the diameter at the K value minimum value was used as the measurement value of the sample. Then, using the displacement amount (μm) with respect to the diameter at the K value minimum value, the compression rate (%) indicating the K value minimum value was calculated based on the following formula.
Compression rate (%) indicating K value minimum value = [average value of displacement with respect to diameter at minimum K value (μm) / number average particle diameter (μm)] × 100
In addition, the value (K value) of the compression elastic modulus in each displacement amount was obtained in the same manner as the 10% K value and the 20% K value.

<Compression deformation recovery rate of resin particles>
Using a micro-compression tester (“MCT-W500” manufactured by Shimadzu Corporation), a circular flat plate indenter with a diameter of 50 μm is used for one particle dispersed on a sample stage (material: SKS flat plate) at room temperature (25 ° C.). Using (material: diamond), in the “soft surface detection” mode, compress to the maximum load (49 mN) at a constant load speed (2.23 mN / sec) toward the center of the particle, and the amount of displacement (μm) at that time Was measured, and this was taken as the maximum displacement L1. Next, the displacement (μm) between the maximum load and the minimum load when the load is reduced to the minimum load (0.49 mN) at a constant unloading speed (2.23 mN / sec) is measured. Was the recovery displacement L2. In addition, the measurement was performed on 10 different particles for each sample, and the average value was used as the measurement value.
Compression deformation recovery rate (%) = (L2 / L1) × 100

2. 2. Production of conductive fine particles 2-1. Production of substrate (resin particles) (Production Example 1)
In a four-necked flask equipped with a condenser, a thermometer, and a dripping port, 250 parts of ion-exchanged water and 0.5 part of 25% ammonia water are added and the monomer component (seed forming monomer) is added from the dripping port with stirring. ), 40 parts of 3-methacryloxypropyltrimethoxysilane and 150 parts of methanol are added, and hydrolysis and condensation reaction of 3-methacryloxypropyltrimethoxysilane is performed to obtain polymerizable polysiloxane particles having a methacryloyl group (seed Particles) was prepared. The number-based average particle diameter of the polysiloxane particles was 10.00 μm.

  Next, 5.0 parts of a 20% aqueous solution of polyoxyethylene styrenated ammonium sulfate ester ammonium salt (“HITENOL (registered trademark) NF-08” manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) as an emulsifier is dissolved in 200 parts of ion-exchanged water. In this solution, 140 parts of methyl methacrylate and 60 parts of ethylene glycol dimethacrylate as monomer components (absorbing monomers) and 2,2′-azobis (2,4-dimethylvaleronitrile) (“V” manufactured by Wako Pure Chemical Industries, Ltd.) -65 ") 5 parts dissolved solution was added and emulsified and dispersed to prepare an emulsion of monomer component (absorbing monomer). Two hours after the start of emulsification dispersion, the obtained emulsion was added to a dispersion of polysiloxane particles (seed particles), and further stirred. One hour after the addition of the emulsified liquid, the mixed liquid was sampled and observed with a microscope. As a result, it was confirmed that the polysiloxane particles were absorbed and absorbed.

  Next, 50.0 parts of a 10% aqueous solution of polyvinyl alcohol was added, the reaction solution was heated to 65 ° C. under a nitrogen atmosphere, and held at 65 ° C. for 3 hours to perform radical polymerization of the monomer component. The emulsion after radical polymerization was subjected to solid-liquid separation, and the obtained cake was washed with ion-exchanged water and methanol, and then vacuum-dried at 120 ° C. for 2 hours in a nitrogen atmosphere to obtain resin particles (1). Compression showing average particle diameter, CV value, 10% K value, 20% K value, 10% K value / 20% K value, compression deformation recovery rate, K value minimum value, K value minimum value of the obtained resin particles The rates were as shown in Table 1.

(Production Example 2)
Resin particles (2) were obtained in the same manner as in Production Example 1 except that the amount of the absorbing monomer used in Production Example 1 was changed to 180 parts methyl methacrylate and 20 parts ethylene glycol dimethacrylate. Compression showing average particle diameter, CV value, 10% K value, 20% K value, 10% K value / 20% K value, compression deformation recovery rate, K value minimum value, K value minimum value of the obtained resin particles The rates were as shown in Table 1.

(Production Example 3)
In Production Example 2, the preparation of the dispersion of polysiloxane particles (seed particles) was the same as Production Example 2 except that the amount of ion exchange water was changed to 350 parts and the amount of methanol used was changed to 210 parts. Thus, a dispersion of polymerizable polysiloxane particles (seed particles) having a methacryloyl group was prepared. The number average particle diameter of the polysiloxane particles was 7.46 μm. Further, in the same manner as in Production Example 2, absorption of the absorbing monomer into the seed particles and radical polymerization were performed to obtain resin particles (3). Compression showing average particle diameter, CV value, 10% K value, 20% K value, 10% K value / 20% K value, compression deformation recovery rate, K value minimum value, K value minimum value of the obtained resin particles The rates were as shown in Table 1.

(Production Example 4)
In Production Example 1, the type and amount used of the absorbing monomer was changed to 200 parts of methyl methacrylate, and the drying was performed by vacuum drying at 80 ° C. for 12 hours in a nitrogen atmosphere, as in Production Example 1. Resin particles (4) were obtained. Compression showing average particle diameter, CV value, 10% K value, 20% K value, 10% K value / 20% K value, compression deformation recovery rate, K value minimum value, K value minimum value of the obtained resin particles The rates were as shown in Table 1.

(Production Example 5)
Resin particles (5) were obtained in the same manner as in Production Example 1 except that the type and amount of the absorbing monomer were changed to 180 parts of methyl methacrylate and 20 parts of tetraethylene glycol dimethacrylate in Production Example 1. Compression showing average particle diameter, CV value, 10% K value, 20% K value, 10% K value / 20% K value, compression deformation recovery rate, K value minimum value, K value minimum value of the obtained resin particles The rates were as shown in Table 1.

(Production Example 6)
In Production Example 1, resin particles (6) were obtained in the same manner as in Production Example 1, except that the type and amount of the absorbing monomer were changed to 180 parts methyl methacrylate and 20 parts 1,6-hexanediol dimethacrylate. It was. Compression showing average particle diameter, CV value, 10% K value, 20% K value, 10% K value / 20% K value, compression deformation recovery rate, K value minimum value, K value minimum value of the obtained resin particles The rates were as shown in Table 1.

(Production Example 7)
In Production Example 1, in preparing a dispersion of polysiloxane particles (seed particles), the same as Production Example 1 except that the amount of ion-exchanged water used was changed to 450 parts and the amount of methanol used was changed to 270 parts. Thus, a dispersion of polymerizable polysiloxane particles (seed particles) having a methacryloyl group was prepared. The number-based average particle diameter of the polysiloxane particles was 6.70 μm. Further, by absorbing the absorption monomer into the seed particles and performing radical polymerization in the same manner as in Production Example 1, except that the type and amount of the absorption monomer were changed to 540 parts of methyl methacrylate and 60 parts of ethylene glycol dimethacrylate. Resin particles (7) were obtained. Compression showing average particle diameter, CV value, 10% K value, 20% K value, 10% K value / 20% K value, compression deformation recovery rate, K value minimum value, K value minimum value of the obtained resin particles The rates were as shown in Table 1.

(Production Example 8)
In Production Example 7, resin particles (8) were obtained in the same manner as in Production Example 7, except that the type and amount of the absorbing monomer were changed to 900 parts methyl methacrylate and 300 parts ethylene glycol dimethacrylate. Compression showing average particle diameter, CV value, 10% K value, 20% K value, 10% K value / 20% K value, compression deformation recovery rate, K value minimum value, K value minimum value of the obtained resin particles The rates were as shown in Table 1.

As a result of measuring the silicon content in the resin particles (1) to (8) obtained in the above Production Examples 1 to 8, each resin particle was 3% by mass or less in terms of Si. The silicon content is calculated by calculating the mass corresponding to the Si content from the mass of ash when 1 g of the resin particles are fired at 1000 ° C. in an air atmosphere (this is the SiO ₂ content), and the Si content is calcined. It was obtained by dividing by the mass of the resin particles subjected to 1. The mass corresponding to the Si content from the ash mass was determined by multiplying the ash mass by 0.4672 (Si atomic weight / SiO ₂ formula weight).

(Production Example 9)
In Production Example 1, resin particles (9) were obtained in the same manner as in Production Example 1 except that the type and amount of the absorbing monomer were changed to 200 parts of ethylene glycol dimethacrylate. Compression showing average particle diameter, CV value, 10% K value, 20% K value, 10% K value / 20% K value, compression deformation recovery rate, K value minimum value, K value minimum value of the obtained resin particles The rates were as shown in Table 2.

(Production Example 10)
In Production Example 1, the type and amount of the absorption monomer were 50 parts methyl methacrylate, 50 parts ethylene glycol dimethacrylate, and “DVB960” manufactured by Nippon Steel Chemical Co., Ltd. (divinylbenzene 96%, vinyl non-crosslinkable monomer (ethyl Resin particles (10) were obtained in the same manner as in Production Example 1 except that the content was changed to 100 parts of vinylbenzene or the like) 4% -containing product). Compression showing average particle diameter, CV value, 10% K value, 20% K value, 10% K value / 20% K value, compression deformation recovery rate, K value minimum value, K value minimum value of the obtained resin particles The rates were as shown in Table 2.

(Production Example 11)
Into a four-necked flask equipped with a condenser, a thermometer, and a dripping port, put 300 parts of ion-exchanged water and 0.3 part of 25% ammonia water, and stir the monomer component (seed forming monomer) from the dripping port. ), 30 parts of phenyltrimethoxysilane and 60 parts of methanol were added, and a hydrolysis and condensation reaction of phenyltrimethoxysilane was performed to prepare a dispersion of polysiloxane particles (seed particles). The number-based average particle size of the polysiloxane particles was 8.20 μm.

  Next, a solution obtained by dissolving 21 parts of a 20% aqueous solution of polyoxyethylene styrenated phenyl ether sulfate ammonium salt (“HITENOL (registered trademark) NF-08” manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) as an emulsifier in 900 parts of ion-exchanged water. In addition, as a monomer component (absorbing monomer), 900 parts of “DVB960” manufactured by Nippon Steel Chemical Co., Ltd. (containing 96% divinylbenzene and 4% vinyl-based non-crosslinkable monomer (such as ethylvinylbenzene)), 2 parts , 2'-azobis (2,4-dimethylvaleronitrile) ("V-65" manufactured by Wako Pure Chemical Industries, Ltd.) 9 parts was added and emulsified to disperse the monomer component (absorbing monomer). An emulsion was prepared. Two hours after the start of emulsification dispersion, the obtained emulsion was added to a dispersion of polysiloxane particles (seed particles), and further stirred. After 80 hours from the addition of the emulsified liquid, the mixed liquid was sampled and observed with a microscope. As a result, it was confirmed that the polysiloxane particles were absorbed and absorbed.

  Next, 372.0 parts of a 10% aqueous solution of polyvinyl alcohol was added, the reaction solution was heated to 65 ° C. under a nitrogen atmosphere, and held at 65 ° C. for 3 hours to perform radical polymerization of the monomer component. The emulsion after radical polymerization was subjected to solid-liquid separation, and the obtained cake was washed with ion-exchanged water and methanol, and then vacuum-dried at 120 ° C. for 2 hours in a nitrogen atmosphere to obtain resin particles (11). Compression showing average particle diameter, CV value, 10% K value, 20% K value, 10% K value / 20% K value, compression deformation recovery rate, K value minimum value, K value minimum value of the obtained resin particles The rates were as shown in Table 2.

(Production Example 12)
In Production Example 1, in preparing a dispersion of polysiloxane particles (seed particles), the same as Production Example 1 except that the amount of ion-exchanged water used was changed to 400 parts and the amount of methanol used was changed to 320 parts. Thus, a dispersion of polymerizable polysiloxane particles (seed particles) having a methacryloyl group was prepared. The number-based average particle size of the polysiloxane particles was 5.18 μm. Furthermore, the type and amount used of the absorbing monomer was changed to 200 parts “DVB960” manufactured by Nippon Steel Chemical Co., Ltd. (containing 96% divinylbenzene and 4% vinyl non-crosslinkable monomer (ethylvinylbenzene, etc.)). Except for the above, resin particles (12) were obtained by carrying out absorption of the absorbing monomer into the seed particles and radical polymerization in the same manner as in Production Example 1. Compression showing average particle diameter, CV value, 10% K value, 20% K value, 10% K value / 20% K value, compression deformation recovery rate, K value minimum value, K value minimum value of the obtained resin particles The rates were as shown in Table 2.

(Production Example 13)
In Production Example 1, in preparing a dispersion of polysiloxane particles (seed particles), the same as Production Example 1 except that the amount of ion-exchanged water used was changed to 480 parts and the amount of methanol used was changed to 300 parts. Thus, a dispersion of polymerizable polysiloxane particles (seed particles) having a methacryloyl group was prepared. The number-based average particle size of the polysiloxane particles was 6.30 μm. Furthermore, absorption of the absorbing monomer into the seed particles and radical polymerization are performed in the same manner as in Production Example 1, except that the type and amount of the absorbing monomer are changed to 720 parts of n-butyl methacrylate and 80 parts of ethylene glycol dimethacrylate. Thus, resin particles (13) were obtained. Compression showing average particle diameter, CV value, 10% K value, 20% K value, 10% K value / 20% K value, compression deformation recovery rate, K value minimum value, K value minimum value of the obtained resin particles The rates were as shown in Table 1.

(Production Example 14)
In Production Example 13, the resin particles (14) were obtained in the same manner as in Production Example 13, except that the type and amount of the absorbing monomer were changed to 720 parts of n-butyl methacrylate and 80 parts of triethylene glycol dimethacrylate. . Compression showing average particle diameter, CV value, 10% K value, 20% K value, 10% K value / 20% K value, compression deformation recovery rate, K value minimum value, K value minimum value of the obtained resin particles The rates were as shown in Table 1.

(Production Example 15)
In Production Example 13, resin particles (15) were obtained in the same manner as in Production Example 13, except that the type and amount of the absorbing monomer were changed to 720 parts of n-butyl methacrylate and 80 parts of tripropylene glycol dimethacrylate. . Compression showing average particle diameter, CV value, 10% K value, 20% K value, 10% K value / 20% K value, compression deformation recovery rate, K value minimum value, K value minimum value of the obtained resin particles The rates were as shown in Table 1.

  As a result of measuring the silicon content in the resin particles (13) to (15) obtained in the above Production Examples 13 to 15, each resin particle was 3% by mass or less, expressed in terms of Si. The silicon content was measured in the same manner as the resin particles (1) to (8).

2-2. Production of conductive fine particles (formation of conductive metal layer)
Example 1
The resin particles (1) used as a base material are subjected to etching treatment with sodium hydroxide, then sensitized by contacting with a tin dichloride solution, and then activated by immersing in a palladium dichloride solution. Palladium nuclei were formed by the method (sensitizing-activation method). Next, 2 parts of resin particles with palladium nuclei formed were added to 400 parts of ion-exchanged water, and after ultrasonic dispersion treatment, the resulting resin particle suspension was heated in a 70 ° C. hot bath. By adding 300 parts of electroless plating solution (“Schumer (registered trademark) S680” manufactured by Nippon Kanisen Co., Ltd.) separately heated to 70 ° C. with the suspension thus heated, electroless nickel is added. A plating reaction was caused. After confirming that the generation of hydrogen gas was completed, solid-liquid separation was performed, followed by washing with ion-exchanged water and methanol in that order, and vacuum drying at 100 ° C. for 2 hours to obtain nickel-plated particles. Next, the obtained nickel plating particles were added to a displacement gold plating solution containing potassium gold cyanide, and gold plating was further performed on the surface of the nickel layer to obtain conductive fine particles. The film thickness of the conductive metal layer in the obtained conductive fine particles was as shown in Table 1.

(Examples 2 to 11, Comparative Examples 1 to 3 and Reference Example 1)
Conductive fine particles were produced in the same manner as in Example 1 except that the resin particles shown in Table 1 were used as the substrate. The film thickness of the conductive metal layer in the obtained conductive fine particles was as shown in Table 1 and Table 2.

3. Preparation and Evaluation of Anisotropic Conductive Material Using conductive fine particles obtained in Examples, Comparative Examples and Reference Examples, an anisotropic conductive material (anisotropic conductive paste) was prepared by the following method, and its performance was evaluated. Evaluation was made by the following method. The evaluation results are shown in Tables 1 and 2.
That is, using three rolls, 100 parts of epoxy resin (Mitsubishi Chemical "JER828") as a binder resin and 1 part of conductive fine particles and a curing agent ("San-Aid (registered trademark) SI-" manufactured by Sanshin Chemical Co., Ltd.) 150 ") and 100 parts of toluene were stirred and dispersed for 10 minutes to obtain a conductive paste.
The obtained anisotropic conductive paste was sandwiched between an entire aluminum vapor-deposited glass substrate having resistance measurement lines and a polyimide film substrate having a copper pattern formed at a pitch of 100 μm, under pressure bonding conditions of 5 MPa and 150 ° C. A connection structure was obtained by thermocompression bonding and curing the binder resin.

  Then, the initial resistance value A between the electrodes of the obtained connection structure is measured. When the initial resistance value A is 3Ω or less, the connection resistance is “◎”. When the initial resistance value A is more than 3Ω and 4Ω or less, the connection resistance is “◯ The connection resistance was evaluated as “Δ” when 4Ω was exceeded and 5Ω or less, and the connection resistance was evaluated as “X” when exceeding 5Ω.

Further, after leaving the obtained connection structure in an atmosphere of 85 ° C. and 85% RH for 500 hours, similarly to the initial resistance value A, the resistance value B after standing for 500 hours was measured, and based on the following formula: When the calculated rate of increase in resistance (%) is 1% or less, the resistance stability with time is “◎”, when it exceeds 1% and 3% or less, “◯”, and when it exceeds 3%, “×”. evaluated.
Resistance value increase rate (%) = [(B−A) / A] × 100

As shown in Tables 1 and 2, in Examples 1 to 11, the recovery rate is lower than in Comparative Examples 1 to 3, and the structural change over time is small in the state after mounting, so that the increase in resistance value is suppressed to a low level. I understand that. Among Examples 1-11, since Example 1 has a high recovery rate and the binder removal property at the time of mounting becomes high, it turns out that initial resistance value is further suppressed low. In Examples 2 to 11, since the recovery rate is lower than that in Example 1, the initial resistance value is high. However, since the change with time after mounting is small, an increase in resistance value is suppressed. Note Example 11, since the 20% K value of the resin particles is less than 1000 N / mm ^2, the 20% K value of the resin particles compared to the other embodiments is 1000 N / mm ² or more, in particular initial resistance value Is high.
On the other hand, the conductive fine particles of Comparative Examples 1 to 3, which are based on resin particles having a recovery rate of more than 65% while having an average particle diameter of 12.5 μm or more, have no problem in the initial resistance value. It can be seen that the resistance value increases with time. The conductive fine particles of Reference Example 1 based on resin particles having an average particle diameter of less than 12.5 μm have a recovery rate exceeding 65%. However, since the particle diameter is small, the resistance value is changed over time. The rise is suppressed.

  The conductive fine particles of the present invention are suitably used for anisotropic conductive materials such as anisotropic conductive pastes, anisotropic conductive films, anisotropic conductive adhesives, anisotropic conductive inks, and the like. In particular, since the conductive fine particles of the present invention have a relatively large particle size, they are useful for anisotropic conductive pastes for LED mounting, for example.

Claims (3)

Conductive fine particles having a base material composed of resin particles and at least one conductive metal layer formed on the surface of the base material,
Conductive fine particles, wherein the resin particles have an average particle diameter of 12.5 μm to 50 μm and a compression deformation recovery rate of 5 to 65% after applying a compression load value of 49 mN. ^2. The conductive fine particle according to claim 1, wherein a compression elastic modulus (20% K value) when the diameter of the resin particle is displaced by 20% is 1000 N / mm ² or more and 14000 N / mm ² or less.   An anisotropic conductive material comprising the conductive fine particles according to claim 1 dispersed in a binder resin.