KR20180006872A - Electroconductive pressure-sensitive adhesive material, and electroconductive pressure-sensitive adhesive material with electroconductive substrate - Google Patents

Abstract

Provided is a conductive adhesive material capable of sufficiently raising the electromagnetic shielding function even if the surface of the adherend has irregularities. The conductive adhesive material according to the present invention comprises a plurality of metal particles, a plurality of conductive particles, and an adhesive component, wherein the conductive particles comprise base particles excluding metal particles and conductive parts disposed on the surface of the base particles And the conductive particles have a plurality of protrusions on the outer surface of the conductive portion.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a conductive adhesive material and a conductive adhesive material with an electrically conductive substrate,

TECHNICAL FIELD The present invention relates to a conductive adhesive material, and more particularly to a conductive adhesive material suitably used for shielding electromagnetic waves. The present invention also relates to a conductive adhesive material with a conductive base using the conductive adhesive.

2. Description of the Related Art Conventionally, in electric or electronic equipment, an electromagnetic wave shielding material is used to protect circuits and electronic component devices.

Generally, as an electromagnetic shielding material, a pressure-sensitive adhesive sheet containing metal particles is used. Further, the pressure-sensitive adhesive sheet may be laminated on a conductive base material.

In addition, Patent Document 1 below discloses the use of a conductive resin composition containing conductive particles and a resin as an electromagnetic wave shielding material. In Patent Document 1, the conductive particles include a core including a conductive material and a coating layer covering the core. The coating layer is formed of a conductive material different from that of the core, and at least a part of the coating layer constitutes an outermost layer.

WO2013 / 132831A1

In the conventional electromagnetic shielding material as in Patent Document 1, the electromagnetic shielding function may not be sufficiently exhibited. In particular, when the surface of the adherend to which the electromagnetic shielding material is applied has irregularities, there is a problem that the electromagnetic shielding function tends to be lowered.

An object of the present invention is to provide a conductive adhesive material capable of sufficiently enhancing an electromagnetic wave shielding function even if there is unevenness on the surface of an adherend. It is also an object of the present invention to provide a conductive adhesive material with a conductive base using the conductive adhesive.

According to a broad aspect of the present invention, there is provided a conductive particle comprising a plurality of metal particles, a plurality of conductive particles, and an adhesive component, wherein the conductive particles comprise base particles excluding metal particles and conductive parts disposed on the surface of the base particles Wherein the conductive particles have a plurality of protrusions on the outer surface of the conductive portion.

In a specific aspect of the conductive adhesive material according to the present invention, the content of the conductive particles in the conductive adhesive agent is from 1 wt% to 30 wt%.

In a specific aspect of the conductive adhesive material according to the present invention, the particle diameter of the conductive particles is 3 탆 or more and 40 탆 or less.

In a specific aspect of the conductive adhesive according to the present invention, the volume resistivity of the conductive particles is 0.001? · Cm or less.

In a specific aspect of the conductive adhesive according to the present invention, the ratio of the particle diameter of the conductive particles to the particle diameter of the metal particles is 0.7 or more and 5,000 or less.

In a specific aspect of the conductive adhesive material according to the present invention, the average height of the projections is 30 nm or more and 1000 nm or less.

In a specific aspect of the conductive pressure-sensitive adhesive according to the present invention, the surface area of the projected portion is 0.1% or more out of 100% of the total surface area of the outer surface of the conductive portion.

In a specific aspect of the conductive adhesive material according to the present invention, the conductive particles comprise a plurality of core materials which rupture the outer surface of the conductive portion.

In a specific aspect of the conductive adhesive according to the present invention, the core material has a material Mohs hardness of 5 or more.

In a specific aspect of the conductive adhesive material according to the present invention, the thickness of the conductive adhesive material is 5 占 퐉 or more and 40 占 퐉 or less.

According to a broad aspect of the present invention, there is provided a conductive adhesive material with a conductive base material, which has the conductive adhesive material and the conductive base material and the conductive adhesive material is disposed on the surface of the conductive base material.

In a specific aspect of the conductive adhesive material with conductive base according to the present invention, the conductive base is a copper foil.

The conductive adhesive material according to the present invention comprises a plurality of metal particles, a plurality of conductive particles, and an adhesive component, wherein the conductive particles comprise base particles excluding metal particles and conductive parts disposed on the surface of the base particles Since the conductive particles have a plurality of projections on the outer surface of the conductive portion, the electromagnetic shielding function can be sufficiently enhanced even if there is irregularity on the surface of the adherend.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a cross-sectional view showing a conductive adhesive material with a conductive base according to an embodiment of the present invention. Fig.
2 is a cross-sectional view showing conductive particles used in the conductive adhesive material with conductive base according to one embodiment of the present invention.
3 is a cross-sectional view showing a first modification of the conductive particle.
4 is a cross-sectional view showing a second modification of the conductive particles.
5 is a cross-sectional view showing a third modification of the conductive particles.
6 is a diagram for explaining a method of evaluating connection resistance.

Hereinafter, the present invention will be described in detail.

The conductive adhesive material according to the present invention is suitably used particularly for shielding electromagnetic waves. The conductive adhesive material according to the present invention is suitably used particularly as an electromagnetic wave shielding material. The conductive adhesive material according to the present invention has an electromagnetic wave shielding function. Further, the conductive adhesive material according to the present invention may be disposed on the surface of the heat-generating component, or may be used as the heat-radiating member.

The conductive adhesive material according to the present invention is an adhesive layer. The conductive adhesive material according to the present invention is suitably used for obtaining the conductive adhesive material with conductive base material comprising the conductive adhesive material (adhesive layer) and the conductive base material. The conductive adhesive material (adhesive layer) may be disposed on the surface of the conductive base material.

The conductive adhesive material according to the present invention includes a plurality of metal particles, a plurality of conductive particles, and an adhesive component.

In the conductive adhesive material according to the present invention, the conductive particles are conductive particles having base particles excluding metal particles and conductive parts disposed on the surface of the base particles.

In the conductive adhesive material according to the present invention, the conductive particles have a plurality of protrusions on the outer surface of the conductive portion.

In the conductive adhesive material according to the present invention, since the above-described structure is employed, even if the surface of the adherend has irregularities, the electromagnetic shielding function can be sufficiently enhanced. Particularly, the use of the above-mentioned metal particles and the conductive particles in combination, the use of the conductive particles having the base particles excluding the metal particles and the conductive parts arranged on the surface of the base particles as the conductive particles, The combination of the constitution in which the particles have protrusions on the outer surface of the conductive portion greatly contributes to the improvement of the electromagnetic shielding function when the electromagnetic shielding material is applied to the roughened surface. In particular, the conductive particles have projections on the outer surface of the conductive portion, so that the conductive adhesive can be favorably followed to the surface of the projections and depressions. As a result, the electromagnetic shielding function is enhanced.

Further, in the conductive adhesive material according to the present invention, the application property is good at the time of forming the conductive adhesive material. In the conductive adhesive material, the dispersibility of the conductive particles is good, the distribution of the adhesive component in the application region is remarkably uniform, and the fluctuation of the adhesive strength can be reduced. By having the above-described configuration, the conductive adhesive material according to the present invention is capable of sufficiently increasing the durability and the heat resistance of the electromagnetic wave shield because the breakage of the conduction path due to the displacement of the adhesive portion due to heat, impact or the like is unlikely to occur. Further, since the conductive adhesive material according to the present invention has the above-described configuration, the heat dissipation property can be sufficiently enhanced when the conductive adhesive material is disposed on the surface of the heat-generating component. In the conductive adhesive according to the present invention, all of the adhesiveness, the connection resistance, the electromagnetic shielding property and the electromagnetic shielding durability can be improved.

In order to effectively enhance the electromagnetic shielding function, in the conductive adhesive according to the present invention, the content of the conductive particles is preferably 1 wt% or more and 30 wt% or less.

Best Mode for Carrying Out the Invention Hereinafter, the present invention will be made clear by describing the present invention in more detail with reference to specific embodiments of the present invention with reference to the drawings.

1 is a cross-sectional view of a conductive adhesive material with a conductive base according to an embodiment of the present invention. The conductive adhesive material with conductive base is provided with a conductive adhesive material.

The conductive adhesive material 51 with a conductive base shown in Fig. 1 has a conductive adhesive material 52 and a conductive base material 53. Fig. The conductive adhesive material 52 is disposed on the surface of the conductive base material 53. The conductive adhesive material 52 includes a plurality of metal particles 56, a plurality of conductive particles 1, and an adhesive component 57.

Hereinafter, the adhesive component included in the conductive base material, the conductive adhesive material, the metal particles contained in the conductive adhesive material, the conductive particles contained in the conductive adhesive material, and the conductive adhesive material will be described in more detail.

(Conductive substrate)

The conductive adhesive material of the present invention can be formed into a conductive adhesive sheet or conductive adhesive tape by disposing the conductive adhesive material on the conductive base material as described above. Examples of the electrically conductive substrate include metal foils, metal meshes, and metal substrates. Examples of the material of the conductive base material include copper and aluminum. Examples of the metal foil include copper foil and aluminum foil.

From the viewpoint of effectively enhancing the electromagnetic shielding function, the conductive base material is preferably a metal base, more preferably a metal foil, a metal mesh or a metal plate, and more preferably a metal foil. The material of the conductive base material is preferably copper or aluminum, more preferably copper. The conductive base material is more preferably a copper foil or an aluminum foil, more preferably a copper foil.

From the viewpoint of effectively enhancing the electromagnetic shielding function, the thickness of the conductive base material is preferably 5 占 퐉 or more, more preferably 10 占 퐉 or more, preferably 40 占 퐉 or less, more preferably 30 占 퐉 or less, Mu] m or less.

(Conductive adhesive material)

From the viewpoint of effectively enhancing the electromagnetic shielding function, the thickness of the conductive adhesive material is preferably 5 占 퐉 or more, more preferably 10 占 퐉 or more, preferably 40 占 퐉 or less, more preferably 30 占 퐉 or less, Mu] m or less.

In recent years, in the case of an adhesive tape, thinness is required. In conventional adhesive tapes using only metal particles, it is difficult to make the thickness of the conductive adhesive material to be 20 mu m or less by agglomeration of the metal particles. In the conductive adhesive material according to the present invention, since the content of the metal particles can be relatively reduced by using the conductive particles, aggregation of the metal particles can be suppressed. As a result, it is possible to make the thickness of the conductive adhesive material 20 mu m or less, and to achieve thinning of the adhesive tape. Further, the pressure-sensitive adhesive sheet and the pressure-sensitive adhesive film are included in the pressure-sensitive adhesive tape.

The ratio of the thickness of the conductive adhesive material to the particle diameter of the conductive adhesive material (the thickness of the conductive adhesive material / the particle diameter of the conductive particles) of the conductive adhesive material before bonding to the adherend is preferably 0.125 or more, more preferably 0.3 or more, Is not less than 0.5, preferably not more than 20, more preferably not more than 10, more preferably not more than 5, more preferably not more than 1.8. When the ratio is above the lower limit and below the upper limit, the electromagnetic shielding function is effectively enhanced.

(Metal particles)

The metal particles are metal particles in which both the central portion and the surface portion are formed of metal. The metal particles do not have base particles except the metal particles in the central portion. The metal species of the center portion and the surface portion may be the same or different.

The metal as the material of the metal particles is not particularly limited. Examples of metals that are the material of the metal particles include gold, silver, copper, palladium, ruthenium, rhodium, iridium, lithium, platinum, zinc, iron, tin, lead, aluminum, cobalt, indium, nickel, chromium, titanium, antimony, , Thallium, germanium, cadmium, silicon, tungsten, molybdenum and their alloys. Examples of the metal include indium tin oxide (ITO) and solder.

Nickel, palladium, silver, copper or gold is preferable, and nickel, palladium, copper or silver is more preferable, and nickel, palladium or copper is more preferable because the electromagnetic shielding function can be effectively increased. More preferably, the conductive portion includes nickel and phosphorus or boron. The material of the metal particles may be an alloy including phosphorus and boron. In the metal particles, nickel, tungsten or molybdenum may be alloyed.

The content of nickel, palladium, copper or silver in 100 wt% of the metal particles is preferably 10 wt% or more, more preferably 25 wt% or more, further preferably 40 wt% or more, preferably 100 wt% (Total amount) or less. The content of nickel in the metal particles is preferably not less than the lower limit and not more than the upper limit.

The metal particles preferably include nickel as a main metal. The metal particles preferably have a content of nickel of 50 wt% or more in 100 wt% of the whole. The content of nickel in the metal particles is preferably at least 65% by weight, more preferably at least 80% by weight, and even more preferably at least 90% by weight, based on 100% by weight of the metal particles. When the content of nickel is less than the lower limit described above, the electromagnetic shielding function is effectively enhanced.

The content of the metal particles in 100 wt% of the conductive adhesive material is preferably 1 wt% or more, more preferably 5 wt% or more, preferably 25 wt% or less, more preferably 15 wt% or less. When the content of the metal particles is not less than the lower limit and not higher than the upper limit, the electromagnetic shielding function is effectively enhanced. In the present invention, since the conductive particles are also used in addition to the metal particles, the content of the metal particles can sufficiently enhance the electromagnetic shielding function.

(Conductive particles)

2 is a cross-sectional view showing conductive particles used in a conductive adhesive material in the conductive adhesive material with conductive base according to an embodiment of the present invention.

The conductive particles 1 shown in Fig. 2 include base particles 2, a conductive portion 3, and a core material 4.

The conductive part 3 is disposed on the surface of the base particle 2. The conductive particles (1) are coated particles in which the surface of the base particles (2) is covered with the conductive parts (3). The conductive portion 3 is a continuous coating.

The conductive particles (1) have a plurality of projections on the conductive surface. The conductive portion 3 has a plurality of projections 3a on its outer surface.

A plurality of core materials (4) are disposed on the surface of the base particles (2). The plurality of core materials 4 are disposed inside the conductive part 3 and are embedded in the conductive part 3. [ The conductive portion 3 covers a plurality of core materials 4. The outer surface of the conductive portion 3 is protruded by the plurality of core materials 4 and the protrusion 3a is formed. The conductive particle 1 has a core material 4 which rises the outer surface of the conductive portion 3 so as to form the projection 3a.

3 is a cross-sectional view showing a first modification of the conductive particle.

The conductive particles 1A shown in Fig. 3 include base particles 2 and conductive portions 3A.

The conductive portion 3A is disposed on the surface of the base particle 2. The conductive particles 1A have a plurality of projections on the conductive surface. The conductive portion 3A has a plurality of projections 3Aa on its outer surface.

The conductive particles 1A do not have a core material. The conductive portion 3A has a first portion and a second portion that is thicker than the first portion. The portion excluding the plurality of projections 3Aa is the first portion of the conductive portion 3A. The plurality of protrusions 3Aa are the second portions in which the conductive portions 3A are thick.

In order to form protrusions like the conductive particles 1A, the core material may not necessarily be used.

4 is a cross-sectional view showing a second modification of the conductive particles.

The conductive particles 1B shown in Fig. 4 include base particles 2, a conductive portion 3B, and a core material 4.

The conductive particles 1B have a plurality of projections on the conductive surface. The conductive portion 3B has a plurality of projections 3Ba on its outer surface.

The positions of the conductive particles (1) and the conductive particles (1B) are different from those of the core material. In the conductive particle 1, a conductive portion 3 having a single-layer structure is formed, whereas in the conductive particle 1B, a conductive portion 3B having multiple layers (two layers) is formed.

The conductive portion 3B has a first conductive portion 3BA and a second conductive portion 3BB. The first and second conductive portions 3BA and 3BB are disposed on the surface of the base particle 2. A first conductive portion 3BA is disposed between the base particle 2 and the second conductive portion 3BB. Therefore, the first conductive portion 3BA is disposed on the surface of the substrate particle 2, and the second conductive portion 3BB is disposed on the surface of the first conductive portion 3BA. The outer shape of the first conductive portion 3BA is spherical. The first conductive portion 3BA does not have a projection on the outer surface. The second conductive portion 3BB has a plurality of projections 3BBa on its outer surface.

A plurality of core materials 4 are arranged on the surface of the first conductive portion 3BA. The plurality of core materials 4 are disposed inside the second conductive portion 3BB and embedded in the second conductive portion 3BB. The second conductive portion 3BB covers a plurality of core materials 4. The outer surface of the conductive portion 3B is protruded by the plurality of core materials 4, and the protrusion 3Ba is formed. The outer surface of the second conductive portion 3BB is raised by the plurality of core materials 4 and the protrusion 3BBa is formed.

Like the conductive particles 1B, the conductive portion may not be a single layer, or may be a multiple layer.

5 is a cross-sectional view showing a third modification of the conductive particles.

The conductive particles 1C shown in Fig. 5 include base particles 2, a conductive portion 3C, and a core material 4.

The conductive particles 1C have a plurality of projections on the conductive surface. The conductive portion 3C has a plurality of projections 3Ca on its outer surface.

The conductive particles (1B) and the conductive particles (1C) differ only in the conductive portions because the positions of the core materials are different.

The conductive portion 3C has a first conductive portion 3CA and a second conductive portion 3CB. The first and second conductive portions 3CA and 3CB are disposed on the surface of the base particle 2. A first conductive portion 3CA is disposed between the base particle 2 and the second conductive portion 3CB. Therefore, the first conductive portion 3CA is disposed on the surface of the base particle 2, and the second conductive portion 3CB is disposed on the surface of the first conductive portion 3CA. The first conductive portion 3CA has a plurality of projections 3CAa on its outer surface. The second conductive portion 3CB has a plurality of projections 3CBa on its outer surface.

A plurality of core materials (4) are disposed on the surface of the base particles (2). The plurality of core materials 4 are disposed inside the conductive portion 3C and embedded in the conductive portion 3C. The plurality of core materials 4 are disposed inside the first conductive portion 3CA and embedded in the first conductive portion 3CA. The conductive portion 3C covers a plurality of core materials 4. [ The outer surface of the conductive portion 3C is protruded by the plurality of core materials 4 and the protrusion 3Ca is formed. The first conductive portion 3CA covers a plurality of core materials 4. The outer surface of the first conductive portion 3CA is raised by the plurality of core materials 4 and the projections 3CAa are formed and the projections 3CBa are formed.

From the viewpoint of effectively enhancing the electromagnetic shielding function, the volume resistivity of the conductive particles is preferably 0.1? 占 ㎝ m or less, more preferably 0.02? 占 이하 m or less, and still more preferably 0.001? 占 ㎝ m or less. The volume resistivity was measured by using a powder resistance meter (MCP-PD51 type, manufactured by Mitsubishi Kaku Arunatech Co., Ltd.) or the like and using 2.5 g of powder, Measured with GXMCP-T700.

The particle diameter of the conductive particles is preferably at least 3 mu m, more preferably at least 5 mu m, even more preferably at least 10 mu m, particularly preferably at least 15 mu m, preferably at most 40 mu m, Is not more than 35 mu m, more preferably not more than 30 mu m, particularly preferably not more than 25 mu m. When the particle diameter of the conductive particles is not lower than the lower limit described above, the thickness of the conductive adhesive material can be sufficiently secured and the contact area between the conductive particles and the adherend is increased, thereby further enhancing the electromagnetic shielding function.

The ratio of the particle diameter of the conductive particles to the particle diameter of the metal particles (the particle diameter of the conductive particles / the particle diameter of the metal particles) is preferably 0.7 or more, more preferably 1 or more, more preferably 15 or more, Particularly preferably 20 or more, preferably 5000 or less, more preferably 4000 or less, further preferably 500 or less. When the ratio is above the lower limit and below the upper limit, the electromagnetic shielding function is effectively enhanced.

The particle diameter per one of the conductive particles and the metal particles indicates the diameter when the conductive particles and the metal particles are in the sphincter shape and the maximum diameter when the conductive particles and the metal particles are not in the spheric shape.

The average height of the protrusions is preferably 30 nm or more, more preferably 100 nm or more, still more preferably 500 nm or more, and preferably 1000 nm or less. When the average height of the protrusions is not less than the lower limit, the contact by the protrusions and the electromagnetic shielding function are further enhanced. When the average height of the projections is less than the upper limit, the projections are hardly broken.

The average height of the projections is an average height of the projections included in one conductive particle. The heights of the protrusions are set so that the imaginary line (the broken line L2 shown in Fig. 2) on the assumption that there is no protrusion on the line connecting the center of the conductive particle and the tip of the protrusion (broken line L1 shown in Fig. 2) ) Phase (on the outer surface of the spherical conductive particle when no projection is assumed) to the tip of the projection. 2, the distance from the intersection of the broken line L1 to the broken line L2 to the tip of the projection is shown.

The surface area of the projected portion is preferably 0.1% or more, more preferably 10% or more of the entire surface area of the outer surface of the conductive portion, from the viewpoint of effectively enhancing the contact with the projections and the electromagnetic shielding function , And more preferably 30% or more. The upper limit of the ratio of the surface area of the protruding portion to the protruding portion out of the total surface area of 100% of the outer surface of the conductive portion is not particularly limited. The surface area of the projected portion may be 99% or less, or 95% or less of the entire surface area of the outer surface of the conductive portion.

The ratio of the surface area of the projected portion can be measured by observing the conductive particles with a scanning electron microscope (SEM) and calculating the projected area ratio of the projected portion to the projected area of the particle diameter of the conductive particles.

The content of the conductive particles in 100 wt% of the conductive adhesive agent is preferably 1 wt% or more, more preferably 5 wt% or more, preferably 30 wt% or less, more preferably 25 wt% Preferably not more than 20% by weight. When the content of the conductive particles is not less than the lower limit and not higher than the upper limit, the electromagnetic shielding function is effectively enhanced.

[Substrate Particle]

The base particles are base particles excluding metal particles. Examples of the base particles include resin particles, inorganic particles other than metal particles, and organic-inorganic hybrid particles. The base particles are preferably resin particles, inorganic particles other than metal particles, or organic-inorganic hybrid particles. The base particles may have a core and a shell disposed on the surface of the core, or may be core shell particles. The core may be an organic core, and the shell may be an inorganic shell.

The base particles are more preferably resin particles or organic-inorganic hybrid particles, and may be resin particles or organic-inorganic hybrid particles. By using these preferable base particles, more suitable conductive particles can be obtained in the electromagnetic wave shielding material.

When the electromagnetic shield member is bonded to the adherend, the electromagnetic shield member is pressed against the adherend. When the base particles are resin particles or organic-inorganic hybrid particles, the conductive particles are easily deformed at the time of pressing, and the contact area between the conductive particles and the adherend becomes large. As a result, the electromagnetic shielding function is further enhanced.

As the resin for forming the resin particles, various organic materials are suitably used. Examples of the resin for forming the resin particles include polyolefin resins such as polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyvinylidene chloride, polyisobutylene, and polybutadiene; Acrylic resins such as polymethyl methacrylate and polymethyl acrylate; Phenol resin, melamine resin, urea resin, benzoguanamine formaldehyde resin, urea formaldehyde resin, phenol resin, melamine resin, benzoguanamine resin, urea resin, urea resin, Various polymerizable monomers having an epoxy resin, an unsaturated polyester resin, a saturated polyester resin, a polysulfone, a polyphenylene oxide, a polyacetal, a polyimide, a polyamideimide, a polyetheretherketone, a polyether sulfone and an ethylenic unsaturated group And polymers obtained by polymerization of one kind or two or more kinds. It is possible to design and synthesize resin particles having physical properties at the time of compression suitable for the electromagnetic wave shielding material and to control the hardness of the base particles to a suitable range easily. Therefore, the resin for forming the resin particles is preferably ethylene It is preferable that the polymer is a polymer obtained by polymerizing one or more polymerizable monomers having unsaturated groups.

When the resin particle is obtained by polymerizing a polymerizable monomer having an ethylenic unsaturated group, examples of the polymerizable monomer having an ethylenic unsaturated group include a monomer that is incompatible with the monomer and a monomer that is crosslinkable.

Examples of the non-crosslinkable monomer include styrene-based monomers such as styrene and? -Methylstyrene; (Meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl Alkyl (meth) acrylates such as methacrylate, lauryl (meth) acrylate, cetyl (meth) acrylate, stearyl (meth) acrylate, cyclohexyl (meth) acrylate and isobornyl Acrylate compounds; (Meth) acrylate compounds such as 2-hydroxyethyl (meth) acrylate, glycerol (meth) acrylate, polyoxyethylene (meth) acrylate and glycidyl (meth) acrylate; Nitrile-containing monomers such as (meth) acrylonitrile; Vinyl ether compounds such as methyl vinyl ether, ethyl vinyl ether and propyl vinyl ether; Acid vinyl ester compounds such as vinyl acetate, vinyl butyrate, vinyl laurate and vinyl stearate; Unsaturated hydrocarbons such as ethylene, propylene, isoprene and butadiene; Halogen-containing monomers such as trifluoromethyl (meth) acrylate, pentafluoroethyl (meth) acrylate, vinyl chloride, vinyl fluoride and chlorostyrene.

Examples of the crosslinkable monomer include tetramethylolmethane tetra (meth) acrylate, tetramethylol methane tri (meth) acrylate, tetramethylol methane di (meth) acrylate, trimethylolpropane tri (meth) (Meth) acrylate, dipentaerythritol penta (meth) acrylate, glycerol tri (meth) acrylate, glycerol di (meth) acrylate, (poly) ethylene glycol di Polyfunctional (meth) acrylate compounds such as (meth) acrylate, (poly) propylene glycol di (meth) acrylate, (poly) tetramethylene glycol di (meth) acrylate and 1,4-butanediol di (meth) acrylate; (Meth) acryloxypropyltrimethoxysilane, trimethoxysilylstyrene, trimethylolpropane trimethoxysilane, triallyl trimellitate, divinyl benzene, diallyl phthalate, diallyl acrylamide, diallyl ether, , Silane-containing monomers such as vinyltrimethoxysilane, and the like.

The above-mentioned resin particles can be obtained by polymerizing the above-mentioned polymerizable monomer having an ethylenic unsaturated group by a known method. This method includes, for example, suspension polymerization in the presence of a radical polymerization initiator and polymerization by swelling the monomer together with radical polymerization initiator using uncrosslinked seed particles.

When the base particles are inorganic particles other than metal particles or organic-inorganic hybrid particles, examples of inorganic materials for forming the base particles include silica, alumina, barium titanate, zirconia, and carbon black. The inorganic material is preferably not a metal. The particles formed by the silica are not particularly limited. For example, particles obtained by hydrolyzing a silicon compound having two or more hydrolyzable alkoxysilyl groups to form crosslinked polymer particles, and then firing if necessary, . Examples of the organic-inorganic hybrid particles include organic-inorganic hybrid particles formed of a crosslinked alkoxysilyl polymer and an acrylic resin.

The organic-inorganic hybrid particles are preferably core-shell type organic-inorganic hybrid particles having a core and a shell disposed on the surface of the core. The core is preferably an organic core. Preferably, the shell is an inorganic shell. From the viewpoint of effectively enhancing the electromagnetic shielding function, the base particles are preferably organic-inorganic hybrid particles having an organic core and an inorganic shell disposed on the surface of the organic core.

Examples of the material for forming the organic core include a resin for forming the above-mentioned resin particles.

Examples of the material for forming the inorganic shell include inorganic materials for forming the base particles described above. The material for forming the inorganic shell is preferably silica. It is preferable that the inorganic shell is formed on the surface of the core by making the metal alkoxide into a shell shape by a sol-gel method and sintering the shell shape. The metal alkoxide is preferably a silane alkoxide. The inorganic shell is preferably formed by silane alkoxide.

The thickness of the shell is preferably 100 nm or more, more preferably 200 nm or more, preferably 5 占 퐉 or less, and more preferably 3 占 퐉 or less. When the thickness of the shell is not less than the lower limit and not more than the upper limit, electroconductive particles more suitable for the electromagnetic shielding material are obtained. The thickness of the shell is an average thickness per base particle. By controlling the sol-gel method, the thickness of the shell can be controlled.

The conductive portion is preferably a conductive layer. The metal as the material of the conductive portion is not particularly limited. Examples of the metal as the material of the conductive portion include gold, silver, copper, palladium, ruthenium, rhodium, iridium, lithium, platinum, zinc, iron, tin, lead, aluminum, cobalt, indium, nickel, chromium, titanium, antimony, bismuth, Thallium, germanium, cadmium, silicon, tungsten, molybdenum and their alloys. Examples of the metal include indium tin oxide (ITO) and solder.

Nickel, palladium, silver, copper or gold is preferable, and nickel, palladium, copper or silver is more preferable, and nickel, palladium or copper is more preferable because the electromagnetic shielding function can be effectively increased. More preferably, the conductive portion includes nickel and phosphorus or boron. The material of the conductive portion may be an alloy including phosphorus and boron. In the conductive portion, nickel, tungsten or molybdenum may be alloyed.

The content of nickel, palladium, copper or silver in the conductive part is preferably 10 wt% or more, more preferably 25 wt% or more, still more preferably 40 wt% or more, and preferably 100 wt% (Total amount) or less. It is preferable that the content of nickel in the conductive portion is not less than the lower limit and not more than the upper limit.

It is preferable that the conductive portion includes nickel as a main metal. It is preferable that the content of nickel is 50% by weight or more in 100% by weight of the entire conductive portion including nickel. In 100 wt% of the conductive part including nickel, the content of nickel is preferably 65 wt% or more, more preferably 80 wt% or more, and even more preferably 90 wt% or more. When the content of nickel is less than the lower limit described above, the electromagnetic shielding function is effectively enhanced.

The method for measuring the content of the metal contained in the conductive portion can be various known analytical methods and is not particularly limited. As the measuring method, an absorption analysis method or a spectrum analysis method can be mentioned. In the above absorption spectrophotometry, a frame absorption spectrophotometer, an electric heating spectrophotometer, or the like can be used. Examples of the spectrum analysis method include a plasma luminescence analysis method and a plasma ion mass spectrometry method.

When measuring the content of the metal contained in the conductive portion, it is preferable to use an ICP emission spectrometer. Commercially available products of the ICP emission spectrometer include ICP emission spectrometers manufactured by HORIBA.

The conductive portion preferably includes phosphorus or boron, and the conductive portion including nickel preferably includes phosphorus or boron. In the case where the conductive portion contains phosphorus or boron, the content of the phosphorus and boron in the total of 100 wt% of the conductive portion containing phosphorus or boron is preferably 0.1 wt% or more, more preferably 1 wt% or more , More preferably not less than 3 wt%, and preferably not more than 10 wt%. If the content of phosphorus and boron is less than the upper limit, the resistance of the conductive portion is further lowered, and the electromagnetic shielding function is effectively increased.

Examples of the method for controlling the content of nickel, boron, and phosphorus in the conductive portion include a method of controlling the pH of the nickel plating solution when forming the conductive portion by electroless nickel plating, a method of controlling the pH of the nickel plating solution by electroless nickel plating A method of adjusting the concentration of the boron-containing reducing agent when forming the conductive portion, a method of adjusting the concentration of the phosphorus-containing reducing agent when forming the conductive portion by electroless nickel plating, a method of adjusting the nickel concentration in the nickel plating solution, .

The conductive portion may be formed by one layer or may be formed by a plurality of layers (multilayer). That is, the conductive portion may be a single layer or may have a laminated structure of two or more layers. When the conductive portion is a multilayer conductive portion, the conductive portion located on the outermost side of the conductive portion has a plurality of projections on the outer surface. When the conductive part is formed by a plurality of layers, the outermost layer is preferably an alloy layer including a gold layer, a nickel layer, a palladium layer, a copper layer, or tin and silver, more preferably a gold layer or a palladium layer , And gold layer are particularly preferable. When the outermost layer is a preferable conductive part of these, the electromagnetic shielding function is effectively enhanced. Further, when the outermost layer is a gold layer, the corrosion resistance is further increased.

The method of forming the conductive portion on the surface of the particles is not particularly limited. Examples of the method for forming the conductive part include a method by electroless plating, a method by electroplating, a method by physical vapor deposition, a method of coating a paste containing metal powder or metal powder and a binder on the surface of particles And the like. Since the formation of the conductive part is simple, a method by electroless plating is preferable. Examples of the physical deposition method include vacuum deposition, ion plating and ion sputtering.

The thickness of the conductive portion (the thickness of the entire conductive portion) is preferably 0.005 탆 or more, more preferably 0.01 탆 or more, preferably 10 탆 or less, more preferably 1 탆 or less, still more preferably 0.5 탆 Or less, particularly preferably 0.3 m or less. The thickness of the conductive portion is the total thickness of the conductive layer when the conductive portion has multiple layers. When the thickness of the conductive portion is not less than the lower limit and not more than the upper limit, the electromagnetic shielding function is effectively increased.

When the conductive portion is formed by a plurality of layers, the thickness of the conductive layer in the outermost layer is preferably 0.001 탆 or more, more preferably 0.01 탆 or more, preferably 0.5 탆 or less, more preferably 0.1 Mu m or less. When the thickness of the conductive layer in the outermost layer is not less than the lower limit and not more than the upper limit, the coating of the outermost conductive layer becomes uniform, and the electromagnetic shielding function is effectively enhanced. Further, when the outermost layer is a gold layer, the thinner the thickness of the gold layer, the lower the cost.

The thickness of the conductive portion can be measured by observing the cross section of the conductive particles using, for example, an electric field type scanning electron microscope (FE-SEM).

The obtained conductive particles are added to " Technobit 4000 " manufactured by Kulzer Co., Ltd. so that the content thereof becomes 30% by weight and dispersed to prepare a buried resin for conductive particle inspection. The cross section of the conductive particles is cut out by using an ion milling apparatus ("IM4000" manufactured by Hitachi High Technologies) so as to pass near the center of the conductive particles dispersed in the inscribed buried resin for inspection.

Then, it is preferable to set an image magnification of 50,000 times using a field emission scanning electron microscope (FE-SEM), randomly select 50 conductive particles, and observe the conductive portions of the respective conductive particles. It is preferable to measure the thickness of the conductive portion in the obtained conductive particles and to calculate the thickness of the conductive portion by arithmetic averaging thereof.

[Core material]

Since the core material is embedded in the conductive portion, it is easy for the conductive portion to have a plurality of protrusions on the outer surface.

Examples of the method for forming the protrusions include a method in which a core material is attached to the surface of base particles and then a conductive portion is formed by electroless plating; a method in which a conductive portion is formed on the surface of base particles by electroless plating, A method of forming a conductive part by electroless plating, and the like. As another method of forming the projections, there are a method of forming a first conductive portion on the surface of base particles, then disposing a core material on the first conductive portion, and then forming a second conductive portion, A method of adding a core material in the middle step of forming a conductive portion (such as a first conductive portion or a second conductive portion) on the surface of the substrate. Further, in order to form the projections, after the conductive parts are formed on the base particles by electroless plating without using the core material, the plating is deposited on the surfaces of the conductive parts in the form of protrusions, A method of forming a portion may be used.

As a method for disposing the core material on the outer surface of the base particle or the conductive part, for example, a core material is added to a dispersion of the particles, and a core material is coated on the surface of the particle, for example, by a van der Waals force A method in which a core material is added to a container containing particles and a core material is adhered to the surface of the particles by a mechanical action by rotating the container or the like. Among them, a method of integrating and adhering the core material on the surface of the base particles in the dispersion is preferable because it is easy to control the amount of the core material to be adhered.

The material of the core material is not particularly limited. It is preferable that the core material has a high Moh hardness.

Specific examples of the material of the core material include barium titanate (Mohs hardness of 4.5), nickel (Mohs hardness of 5), silica (silicon dioxide, Mohs hardness of 6 to 7), titanium oxide (Mohs hardness of 7), zirconia 9), alumina (Mohs hardness 9), tungsten carbide (Mohs hardness 9), and diamond (Mohs hardness 10). The material of the core material is preferably nickel, silica, titanium oxide, zirconia, alumina, tungsten carbide or diamond, more preferably silica, titanium oxide, zirconia, alumina, tungsten carbide or diamond, , Alumina, tungsten carbide, or diamond, and particularly preferably zirconia, alumina, tungsten carbide, or diamond. From the viewpoint of effectively enhancing the electromagnetic shielding function, the material Mohs hardness of the core material is preferably 4 or more, more preferably 5 or more, still more preferably 6 or more, further preferably 7 or more, particularly preferably 7.5 Or more.

The shape of the core material is not particularly limited. The shape of the core material is preferably massive. As the core material, for example, there may be mentioned a lump in the form of a particle, a coagulated mass in which a plurality of small particles are aggregated, and a lump of an indeterminate form.

The average diameter (average particle diameter) of the core material is preferably 0.001 탆 or more, more preferably 0.05 탆 or more, preferably 0.9 탆 or less, and more preferably 0.2 탆 or less. When the average diameter of the core material is above the lower limit and below the upper limit, the electromagnetic shielding function is effectively enhanced.

The " average diameter (average particle diameter) " of the core material indicates a number average diameter (number average particle diameter). The average diameter of the core material is obtained by observing 50 pieces of any core material with an electron microscope or an optical microscope and calculating an average value.

The number of the projections per one conductive particle is preferably 3 or more, and more preferably 5 or more. The upper limit of the number of the projections is not particularly limited. The upper limit of the number of the projections can be appropriately selected in consideration of the particle diameter of the conductive particles and the like.

(Adhesive component)

The conductive adhesive material of the present invention has an adhesive component and is disposed on the conductive base material as described above, whereby the conductive adhesive sheet and the conductive adhesive tape can be formed. Examples of the adhesive component include a rubber-based pressure-sensitive adhesive, an acrylic pressure-sensitive adhesive, a silicone pressure-sensitive adhesive and a polyurethane pressure-sensitive adhesive. The adhesive component may be used alone or in combination of two or more.

The content of the adhesive component is preferably 5% by weight or more, more preferably 15% by weight or more, preferably 60% by weight or less, and still more preferably 35% by weight or less in 100% by weight of the conductive adhesive material. When the content of the adhesive component is not less than the lower limit and not more than the upper limit, the electromagnetic shielding function is effectively increased.

Hereinafter, the present invention will be described in more detail based on concrete examples. The present invention is not limited to the following examples.

In the following examples, a powder resistivity meter ("MCP-PD51 type" manufactured by Mitsubishi Chemical Corporation) was used, and 2.5 g of powder was used, and a pressure of 20 kN, Loresta GXMCP -T700, the conductive particles having a volume resistivity of 0.001? · Cm or less were used.

(Example 1)

(1) Preparation of a solution of a conductive adhesive material for forming a conductive adhesive material

40 parts by weight of 2-phenoxyethyl methacrylate, 58 parts by weight of n-butyl methacrylate, and 2 parts by weight of methacrylic acid were added to a solution prepared by dissolving 40 parts by weight of azobisisobutyronitrile as an initiator, (Solid content concentration: 45% by weight) of a polymer having a weight average molecular weight of about 400,000 was obtained by polymerizing by a solution polymerization method (60 DEG C for 4 hours and 85 DEG C for 1 hour). To 100 parts by weight of the solid content of the acrylic polymer solution, 40 parts by weight of polymerized rosin pentaerythritol ester (" Harieste S ", manufactured by Harima Chemicals, Inc.) as a tackifier resin was blended to prepare an acrylic resin composition solution.

7 parts by weight of nickel powder ("NFP201X / XD200 nm" manufactured by JFE Minerals Co., Ltd.) as metal particles, 7 parts by weight of conductive particles (NIEZB-020-S manufactured by Sekisui Chemical Co., Ltd., 8 parts by weight of plated metal species: nickel), 100 parts by weight of ethyl acetate and 2 parts by weight of an isocyanate crosslinking agent (Coronate L, manufactured by Nippon Polyurethane Industry Co., Ltd.) were mixed with a stirrer for 10 minutes to prepare a solution of a conductive adhesive Pressure-sensitive adhesive solution). The average height of the projections in the conductive particles was 500 nm. The ratio of the surface area of the protruding portion of the conductive particles measured by the above-described method (coating ratio by protrusions) was 30%.

(2) Production of conductive adhesive material with conductive base material

A copper foil having a thickness of 12 탆 was prepared. A conductive adhesive material (pressure-sensitive adhesive layer) was formed on the copper foil so as to have a thickness of 20 占 퐉 using a solution of the conductive adhesive material and aged at 50 占 폚 for one day to form a conductive adhesive layer Thereby obtaining a conductive adhesive material. In the obtained conductive adhesive, the content of the conductive particles was 8 wt% and the content of the metal particles was 7 wt%.

(Example 2-3)

A conductive adhesive material with a conductive base material was obtained in the same manner as in Example 1 except that the particle diameter of the conductive particles was changed as shown in Table 1.

(Example 4)

A conductive adhesive material with a conductive base material was obtained in the same manner as in Example 1 except that the particle diameter of the conductive particles and the particle diameter of the metal particles were changed as shown in Table 1.

(Examples 5-8)

A conductive adhesive material with a conductive base material was obtained in the same manner as in Example 1, except that the particle diameter of the metal particles was changed as shown in Table 1.

(Example 9)

A conductive adhesive material with a conductive base material was obtained in the same manner as in Example 1, except that the particle diameter of the metal particles and the thickness of the conductive adhesive material were changed as shown in Table 1.

(Example 10)

A conductive adhesive material with conductive base material was obtained in the same manner as in Example 1, except that the thickness of the conductive adhesive material was changed as shown in Table 1.

(Examples 11-12)

A conductive adhesive material with a conductive base material was obtained in the same manner as in Example 1, except that the particle diameter of the metal particles and the thickness of the conductive adhesive material were changed as shown in Table 1.

(Examples 13-14)

A conductive adhesive material with a conductive base material was obtained in the same manner as in Example 1, except that the average height of protrusions of the conductive particles was changed as shown in Table 1.

(Examples 15-18)

A conductive adhesive material with a conductive base material was obtained in the same manner as in Example 1, except that the plating metal species of the conductive portion of the conductive particles was changed as shown in Table 1.

(Examples 19-23)

A conductive adhesive material with a conductive base material was obtained in the same manner as in Example 1 except that the content of the conductive particles and the content of the metal particles in the conductive adhesive material obtained were changed as shown in Table 2.

(Examples 24-25)

A conductive adhesive material with a conductive base material was obtained in the same manner as in Example 1 except that the particle diameter of the conductive particles was changed as shown in Table 2.

(Examples 26-27)

A conductive adhesive material with a conductive base material was obtained in the same manner as in Example 1, except that the average height of protrusions of the conductive particles was changed as shown in Table 2.

(Example 28)

A conductive adhesive material with a conductive base material was obtained in the same manner as in Example 1, except that the thickness of the conductive adhesive material was changed as shown in Table 2.

(Example 29)

A conductive adhesive material with conductive base material was obtained in the same manner as in Example 1, except that the particle diameter of the conductive particles and the thickness of the conductive adhesive material were changed as shown in Table 2.

(Example 30)

A conductive adhesive material with a conductive base material was obtained in the same manner as in Example 1, except that the particle diameter of the metal particles was changed as shown in Table 2.

(Examples 31-32)

A conductive adhesive material with a conductive base material was obtained in the same manner as in Example 4, except that the covering ratio of the conductive particles with the projections was changed as shown in Table 2.

(Example 33)

A conductive adhesive material with conductive base material was obtained in the same manner as in Example 4, except that the plating metal species (layer configuration, outermost layer Ag / inner layer Cu) of the conductive part of the conductive particles was changed as shown in Table 2.

(Comparative Example 1)

As shown in Table 2, the conductive adhesive material with conductive base material was obtained in the same manner as in Example 1, except that the content of the conductive particles in the conductive adhesive material was changed and no metal particles were used in the conductive adhesive material.

(Comparative Example 2)

As shown in Table 2, the conductive adhesive material with conductive base material was obtained in the same manner as in Example 1, except that the content of the metal particles in the conductive adhesive material was changed and the conductive particles were not used as the conductive adhesive material.

(Comparative Example 3)

A conductive adhesive material with conductive base material was obtained in the same manner as in Example 1, except that the conductive particles having no projections (average height of projections: 0 nm) were used as shown in Table 2.

(Example 34)

A conductive adhesive material with a conductive base material was obtained in the same manner as in Example 4, except that the covering ratio of the conductive particles with the projections was changed as shown in Table 2.

(evaluation)

(1) Tackiness

A test piece (conductive adhesive material with conductive base material) was bonded to the stainless steel plate from the side of the conductive adhesive material, and the force required to peel the test piece from the test plate in the 180 ° direction was evaluated. The tensile speed was 30 mm / min and the tape width was 25 mm. From the force required to detach, the stickiness was judged by the following criteria.

[Judgment criteria of stickiness]

OOX: 15N / ㎟ or more

○○: 10N / ㎟ or more and less than 15N / ㎟

?: Less than 4N / mm2 and less than 10N / mm2

?: 1 N / mm 2 or more and less than 4 N / mm 2

×: less than 1 N / mm 2

(2) Connection resistance

The conductive adhesive material 61 with a conductive base material was adhered to the lower pure copper electrode 62 (25 mm x 25 mm) from the adhesive side and placed between the upper pure copper electrode 63 as shown in Fig. 6, The connection resistance was measured using the four-terminal method. The planar area of the conductive adhesive material with conductive base was 10 x 10 mm. The connection resistance was judged according to the following criteria.

[Criteria for judging connection resistance]

X: Less than 2 Ω

○○: 2Ω or more and less than 5Ω

○: 5Ω or more and less than 10Ω

?: 10? Or more and less than 30?

×: 30Ω or more

(3) Electromagnetic wave shielding property

The electromagnetic shielding property of the conductive adhesive material with conductive base material was evaluated using the KEC method (magnetic field) of KEC Kansai Industrial Promotion Center development. The shielding effect for 1 GHz high frequency was used as a comparison standard, and the electromagnetic shielding property was evaluated from the value of the obtained shielding effect.

[Judgment criteria of electromagnetic wave shielding property]

○○○: 90dB or more

○○: Less than 75dB and less than 90dB

○: 60 dB or more and less than 75 dB

△: Less than 40 dB and less than 60 dB

×: Less than 40 dB

(4) Durability of electromagnetic wave shield

The conductive adhesive material with conductive base material was subjected to a heat cycle test under the following heat cycle conditions, and the shielding property was evaluated by the KEC method. The shielding effect for 1 GHz high frequency was taken as a comparison standard, and the electromagnetic wave shield durability was evaluated from the value of the obtained shielding effect.

Heat cycle conditions: low temperature side: -10 占 폚 / 30 min, high temperature side: 120 占 폚 / 30 min, total 250 cycles.

[Judgment criteria of electromagnetic wave shielding durability]

○○○: Over 80dB

○○: Less than 65dB and less than 80dB

○: Less than 50 dB and less than 65 dB

?: 40 dB or more and less than 50 dB

×: Less than 40 dB

The details of the conductive adhesive material with conductive base and the evaluation results are shown in Tables 1 to 3 below.

1, 1A, 1B, 1C: conductive particles
2: Base particles
3, 3A, 3B, 3C:
3a, 3Aa, 3Ba, 3Ca:
3BA, 3CA: first conductive part
3CAa: projection
3BB, 3CB: second conductive portion
3BBa, 3CBa: projection
4: core material
51: Conductive adhesive material with conductive base material
52: conductive adhesive material
53: conductive substrate
56: metal particles
57: Adhesive component

Claims (12)

A plurality of metal particles, a plurality of conductive particles, and an adhesive component,
Wherein the conductive particles are conductive particles having a base particle excluding metal particles and a conductive portion disposed on a surface of the base particle,
Wherein the conductive particles have a plurality of protrusions on the outer surface of the conductive portion. The conductive adhesive material according to claim 1, wherein the content of the conductive particles in the conductive adhesive material is 1 wt% or more and 30 wt% or less. The conductive adhesive material according to claim 1 or 2, wherein the conductive particles have a particle diameter of 3 탆 or more and 40 탆 or less. The conductive adhesive material according to any one of claims 1 to 3, wherein the conductive particles have a volume resistivity of 0.001? · Cm or less. The conductive adhesive material according to any one of claims 1 to 4, wherein the ratio of the particle diameter of the conductive particles to the particle diameter of the metal particles is 0.7 to 5,000. The conductive adhesive material according to any one of claims 1 to 5, wherein the average height of the projections is 30 nm or more and 1000 nm or less. The conductive adhesive material according to any one of claims 1 to 6, wherein a surface area of the projected portion is 0.1% or more out of 100% of the total surface area of the outer surface of the conductive portion. The conductive adhesive material according to any one of claims 1 to 7, wherein the conductive particles comprise a plurality of core materials which rid the outer surface of the conductive portion. The conductive adhesive material according to claim 8, wherein the material of the core material has a Mohs hardness of 5 or more. The conductive adhesive material according to any one of claims 1 to 9, wherein the thickness is not less than 5 占 퐉 and not more than 40 占 퐉. A conductive adhesive material according to any one of claims 1 to 10,
And a conductive substrate,
Wherein the conductive adhesive material is disposed on a surface of the conductive base material. The conductive adhesive material according to claim 11, wherein the conductive base material is a copper foil.

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