TW202113877A - Composition for electromagnetic wave shielding, sheet for electromagnetic wave shielding, sintered body for electromagnetic wave shielding, and electronic component device - Google Patents

Abstract

A composition for electromagnetic wave shielding includes a metal particle A, a metal particle B having a lower melting point than the metal particle A, and a resin, in which transient liquid phase sintering between the metal particle A and the metal particle B is possible.

Description

Electromagnetic wave shielding composition, electromagnetic wave shielding sheet, electromagnetic wave shielding sintered body, and electronic component device

The present disclosure relates to an electromagnetic wave shielding composition, an electromagnetic wave shielding sheet, a sintered body for electromagnetic wave shielding, and an electronic component device.

If unnecessary electromagnetic waves enter electronic equipment from the outside, malfunctions may occur. Therefore, electronic equipment uses electromagnetic wave shielding materials that shield unnecessary electromagnetic waves from the outside.

Many electromagnetic wave shielding materials contain metal, which shields electronic equipment from electromagnetic waves by reflecting electromagnetic waves.

Examples of conventional electromagnetic wave shielding materials include metal plating, metal frame, and metal paint. However, metal plating tends to take a long time to process and high prices. In addition, with the miniaturization of electronic devices, it is necessary to reduce the size of the metal frame, and the processing of the metal frame tends to become difficult.

On the other hand, the metal coating contains metal particles, resin, and solvent, and conduction is obtained by the contact of the metal particles. The lower the volume resistivity of the coating film formed of the metallic paint, the more the electromagnetic wave shielding properties of the coating film tend to improve. Therefore, it is desirable to increase the contact points between the metal particles by using flat metal particles to reduce the volume resistivity of the coating film (for example, refer to Patent Document 1). [Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2002-150837

[The problem to be solved by the invention] However, even if flat metal particles are used, there is a limit in reducing the volume resistivity of the coating film. As another method of reducing the volume resistivity of the coating film, a method of increasing the amount of metal particles added to increase the contact points between the metal particles can be considered. However, the amount of metal particles added also has a limit, and sometimes it is difficult to exhibit the required characteristics. The present disclosure is made in view of the above-mentioned existing situation, and its object is to provide an electromagnetic wave shielding composition capable of forming a sintered body for electromagnetic wave shielding with excellent electromagnetic wave shielding effect, and an electromagnetic wave shielding sheet and electromagnetic wave shielding sheet using the electromagnetic wave shielding composition Sintered body for shielding and electronic component device.

[Means for Solving the Problem] The specific means for achieving the above-mentioned problem are as follows. <1> An electromagnetic wave shielding composition containing metal particles A, metal particles B having a lower melting point than the metal particles A, and resin, and capable of performing a transient state between the metal particles A and the metal particles B Liquid phase sintering. <2> The electromagnetic wave shielding composition according to <1>, wherein the melting point of the metal particles B is 300°C or less. <3> The electromagnetic wave shielding composition according to <1> or <2>, wherein the metal particles A include Cu, and the metal particles B include Sn. <4> The electromagnetic wave shielding composition according to <3>, wherein the content ratio of Cu in the whole of the metal particles A and the metal particles B and Sn in the metal particles on a mass basis The ratio of the content ratio (Cu content ratio/Sn content ratio) occupied by the whole of A and the metal particles B is 0.6-21. <5> The electromagnetic wave shielding composition according to <3>, wherein the content ratio of Cu in the whole of the metal particles A and the metal particles B and the content of Sn in the metal particles on a mass basis The ratio of the content ratio (Cu content ratio/Sn content ratio) occupied by the whole of A and the metal particles B is 1.6 to 64. <6> The electromagnetic wave shielding composition according to any one of <3> to <5>, wherein the metal particle B further contains Bi, and Cu is contained in the metal particle A and the metal particle A on a mass basis. The ratio (Cu content/Bi content) of the content ratio of the entire metal particle B to the content ratio of Bi in the entire metal particle A and the metal particle B (Cu content/Bi content) is 1.1 to 44. <7> The electromagnetic wave shielding composition according to any one of <1> to <6>, wherein the total ratio of the metal particles A and the metal particles B in the total solid content is 96% by mass the following. <8> The electromagnetic wave shielding composition according to any one of <1> to <7>, wherein the resin contains a thermosetting resin. <9> The electromagnetic wave shielding composition as described in <8> further contains a curing agent. <10> The electromagnetic wave shielding composition as described in <8> or <9> further contains a hardening accelerator. <11> The composition for electromagnetic wave shielding as described in any one of <1> to <10> further contains a flux component. <12> The electromagnetic wave shielding composition according to <11>, wherein the flux component contains at least one of rosin and an activator. <13> The electromagnetic wave shielding composition according to <12>, wherein the rosin contains 2,2-bis(hydroxymethyl)propionic acid, and the active agent contains triethanolamine. <14> The electromagnetic wave shielding composition according to <11>, wherein the temperature at which the flux component undergoes a phase change is α (°C), and the melting point of the metal particles B is β (°C) At this time, the flux composition satisfies β-20≦α≦β+20. <15> The electromagnetic wave shielding composition according to <14>, wherein the temperature at which the flux component undergoes a phase change is 130°C to 160°C. <16> The composition for electromagnetic wave shielding as described in <14> or <15>, wherein the flux component is selected from propionic acid, 4-aminosalicylic acid and 3-(benzylamino)propionic acid At least one of the group consisting of ethyl esters. <17> The electromagnetic wave shielding composition as described in any one of <1> to <16> further contains a solvent. <18> An electromagnetic wave shielding sheet having a resin composition layer containing the electromagnetic wave shielding composition according to any one of <1> to <17>. <19> A sintered body for electromagnetic wave shielding, which is a sintered body of the electromagnetic wave shielding composition described in any one of <1> to <17> or the electromagnetic wave shielding sheet described in <18>. <20> The sintered body for electromagnetic wave shielding as described in <19>, wherein the volume resistivity is 3×10 ^-4 Ω·cm or less. <21> An electronic component device having an area covered by the sintered body for electromagnetic wave shielding as described in <19> or <20>.

[Effects of the invention] According to the present disclosure, it is possible to provide an electromagnetic wave shielding composition capable of forming an electromagnetic wave shielding sintered body with excellent electromagnetic wave shielding effect, and an electromagnetic wave shielding sheet, an electromagnetic wave shielding sintered body, and an electronic component device using the electromagnetic wave shielding composition.

Hereinafter, a mode for implementing the present disclosure will be described in detail. However, this disclosure is not limited to the following embodiments. In the following embodiments, the constituent elements (including element steps, etc.) are not essential unless otherwise specified. The same is true for the numerical value and its range, which does not limit the present disclosure.

In the present disclosure, the term "step" includes a step that is independent of other steps, even if it cannot be clearly distinguished from other steps, as long as the purpose of the step is achieved, the step is also included. In the present disclosure, the numerical range indicated by "～" includes the numerical values described before and after "～" as the minimum value and the maximum value, respectively. In the numerical ranges described stepwise in this disclosure, the upper limit or lower limit described in one numerical range may be replaced with the upper limit or lower limit of another numerical range described stepwise. In addition, in the numerical range described in the present disclosure, the upper limit or lower limit of the numerical range can be replaced with the values shown in the examples. In the present disclosure, each component may also contain multiple equivalent substances. When there are multiple types of substances corresponding to each component in the composition, the content rate of each component refers to the total content rate of the multiple types of substances present in the composition, unless otherwise specified. In the present disclosure, a plurality of particles may be included in the particles corresponding to each component. When there are multiple types of particles corresponding to each component in the composition, unless otherwise specified, the particle diameter of each component refers to a value related to the mixture of the multiple types of particles present in the composition. In the present disclosure, the term "layer" or "film" when observing the area in which the layer or film exists, in addition to the case where the entirety is formed in the area, it also includes only a part of the area. Happening. In this disclosure, the average thickness of a layer or film is measured at 5 points of the target layer or film, and is set to a value given as an arithmetic average value thereof. The thickness of the layer or film can be measured using a micrometer or the like. In the present disclosure, when the thickness of the layer or the film can be directly measured, the measurement is performed using a micrometer. On the other hand, in the case of measuring the thickness of one layer or the total thickness of a plurality of layers, the measurement can also be carried out by observing the cross section of the measurement target using an electron microscope. In the present disclosure, the "solid content" refers to the remaining part after removing the solvent component from the electromagnetic wave shielding composition. The solvent content in the electromagnetic wave shielding composition can be determined by applying an analysis method such as Gas Chromatography/Mass Spectrometry (GC/MS) to the volatile components of the electromagnetic wave shielding composition. Furthermore, when the composition of the electromagnetic wave shielding composition is ascertained, the content of the solvent can also be determined from the composition of the electromagnetic wave shielding composition. The ratio of the remaining part of the electromagnetic wave shielding composition is obtained by multiplying the solvent content rate by the mass of the electromagnetic wave shielding composition.

＜Composition for electromagnetic wave shielding＞ The electromagnetic wave shielding composition of the present disclosure contains metal particles A, metal particles B having a lower melting point than the metal particles A, and resin, and is capable of undergoing a transient liquid phase between the metal particles A and the metal particles B. sintering. The electromagnetic wave shielding composition may contain components other than the above-mentioned components. According to the electromagnetic wave shielding composition of the present disclosure, the transient liquid phase sintering generated between the metal particle A and the metal particle B can be used to form a sintered body of the metal particle A and the metal particle B by heating. Compared with the case where metal particles are in contact with each other, the formed sintered body tends to have low interface resistance and excellent conductivity. As a result, it is estimated that the sintered body for electromagnetic wave shielding formed using the electromagnetic wave shielding composition of the present disclosure has low volume resistivity and excellent electromagnetic wave shielding effect.

Hereinafter, the components constituting the electromagnetic wave shielding composition of the present disclosure will be described in detail.

(Metal particles) The electromagnetic wave shielding composition of the present disclosure contains metal particles A and metal particles B having a lower melting point than metal particles A. Between the metal particles A and the metal particles B, transient liquid phase sintering can be performed. The “transient liquid phase sintering” in this disclosure is also called Transient Liquid Phase Sintering (TLPS), which refers to the following phenomenon: the metal with different melting points (low melting point metal) in the particle interface The transition to the liquid phase caused by heating and the reactive diffusion of a metal with a relatively high melting point (a high melting point metal) into the liquid phase progresses the formation (alloying) of a metal compound based on the two metals. Utilizing this phenomenon, a sintered body that can be sintered at a low temperature and has a high melting point after sintering can be obtained. In addition, in the "transient liquid phase sintering" in the present disclosure, as long as at least a part of the metal components contained in the metal particles A and the metal particles B can be sintered, it is not necessary that all the metal components can be sintered. For example, the metal particles B may contain a metal component that does not contribute to the reaction at the time of sintering, such as Bi.

As a metal component capable of transient liquid phase sintering, a combination of metals with different melting points capable of transient liquid phase sintering (combination of a low melting point metal and a high melting point metal) can be cited. The combination of metals that can be subjected to transient liquid phase sintering is not particularly limited. Examples include: low-melting-point metals and high-melting-point metals: a combination of Sn and Cu, a combination of Zn and Cu, and a combination of In and Au. , Respectively are the combination of Sn and Co, and respectively are the combination of Sn and Ni. The combination of metals capable of transient liquid phase sintering may be a combination of two metals, or a combination of three or more metals.

From the viewpoint of the adhesive strength after sintering, the melting point of the metal particles A is preferably higher than 300°C, more preferably 500°C or higher, and still more preferably 800°C or higher. The electromagnetic wave shielding composition of the present disclosure may include two or more kinds of metal particles A, for example, may include two or more kinds of metal particles A each having a melting point higher than 300°C. From the viewpoint of promoting the transition to the liquid phase during sintering, the melting point of the metal particles B is preferably 300°C or lower, more preferably 250°C or lower, still more preferably 200°C or lower, and particularly preferably 150°C or lower. The electromagnetic wave shielding composition of the present disclosure may also include two or more kinds of metal particles B, for example, two or more kinds of metal particles B having a melting point of 300° C. or less.

The specific embodiment of the metal particle A and the metal particle B is not specifically limited. In a certain embodiment, the metal particle A and the metal particle B may be in a state where the metal particle A and the metal particle B are a simple metal, respectively, or one or both of the metal particle A and the metal particle B may be in an alloy state. As a preferred embodiment, the metal particle A is in the state of a simple metal, and the metal particle B is in the state of an alloy.

In addition, in a certain embodiment, each of the metal particles A and the metal particles B may include only one type of metal, or may include two or more types of metals. When the metal particle A or the metal particle B contains two or more metals, the metal particle may be a combination (mixture) of metal particles containing two or more metals, or two or more metals may be contained in the same In the metal particles of, it can also be a combination of these.

The structure of the metal particles containing two or more kinds of metals in the same metal particle is not particularly limited. For example, it may be a metal particle composed of an alloy of two or more metals, or a metal particle composed of a simple substance of two or more metals. Metal particles composed of simple substances of two or more metals can be obtained, for example, by forming a layer including another metal on the surface of a metal particle including one metal by plating, vapor deposition, or the like. In addition, the following method can also be used to dryly apply impact force on the surface of metal particles containing one metal in a high-speed airflow to particles containing another metal and combine the two Method to obtain metal particles containing two or more metals in the same metal particles.

As the metal particle A, it is preferable to include at least one metal particle selected from the group consisting of Cu, Au, Ag, Co, Ni and Fe, more preferably one of Cu, Au, Ag, Co, Ni or Fe particle. The metal particles B are preferably metal particles containing Sn, Zn, or In, and more preferably alloy particles containing Sn, Zn, or In, and a metal component X described later.

Examples of combinations of metal particles A and metal particles B having a lower melting point than metal particles A (metal particles A, metal particles B) include: (metal particles containing Cu, metal particles containing Sn), (metal particles containing Cu Particles, metal particles containing Zn), (metal particles containing Au, metal particles containing In), (metal particles containing Co, metal particles containing Sn), and (metal particles containing Ni, metal particles containing Sn) . In the case where the combination of metal particles A and metal particles B is a combination of metal particles containing Cu and metal particles containing Sn, at least one of the metal particles containing Cu and the metal particles containing Sn contains Ag and Ni. At least one of them has a tendency to suppress the increase in the grain size of the copper-tin alloy.

From the viewpoint of lowering the temperature at which transient liquid phase sintering can be performed, the metal particles B preferably include at least one metal component X selected from the group consisting of Bi, In, Zn, Cd, Pb, Ag, and Cu It is more preferable to include Sn and the metal component X. Furthermore, when the metal particles B include Zn, the metal component X preferably includes at least one selected from the group consisting of Bi, In, Cd, Pb, Ag, and Cu. Where the metal particles B include In In this case, the metal component X preferably includes at least one selected from the group consisting of Bi, Zn, Cd, Pb, Ag, and Cu.

The metal component X more preferably contains at least one selected from the group consisting of Bi, In, Zn, Cd, Ag, and Cu, and from the viewpoint of further lowering the temperature at which transient liquid phase sintering can be performed, it is still more preferable Contains at least one selected from the group consisting of Bi, In, Zn, and Cd.

Regarding the metal particles B, from the viewpoint of lowering the temperature at which transient liquid phase sintering is possible and the viewpoint of suitably reducing the volume resistivity of the sintered body for electromagnetic wave shielding, the ratio of the metal component X to the whole of the metal particles B is relatively high. It is preferably 3% by mass to 80% by mass, more preferably 5% by mass to 15% by mass, 20% by mass to 30% by mass, or 50% by mass to 60% by mass.

Examples of the case where the metal particles B are in an alloy state containing Sn include SnBi alloy, SnIn alloy, SnZn alloy, SnPb alloy, SnCd alloy, and the like. Among them, from the viewpoint of lowering the temperature at which transient liquid phase sintering can be performed, a SnBi alloy is preferable.

In an embodiment, it is preferable that the metal particle A contains Cu (melting point: 1085°C), and the metal particle B contains Sn (melting point: 232°C), and it is preferable that the metal particle A contains Cu (melting point: 1085°C) and metal particles. B is an alloy containing Sn (melting point: less than 232°C, for example, 138°C). Cu and Sn are sintered to produce a copper-tin metal compound (Cu ₆ Sn ₅ ). Since this formation reaction proceeds at around 150°C, it can be sintered using general equipment such as a reflow furnace.

In a certain embodiment, Cu particles can be used as the metal particles A, and alloy particles containing Su can be used as the metal particles B. As an example when Sn is in an alloy state, an alloy containing Su, Ag, and Cu (SAC), an alloy containing Sn and Bi (SnBi), and the like can be cited. The composition of the SnBi alloy is not particularly limited, and for example, Sn-Bi58 can be cited. In the present disclosure, the alloy represented by Sn-XA means that the Sn-containing alloy contains A by mass% of the element X. The melting point (liquid phase transition temperature) of the alloy represented by Sn-Bi58 is about 138°C.

When the metal particle A contains Cu and the metal particle B contains Sn, in a certain embodiment, on a mass basis, the content ratio of Cu in the whole of the metal particle A and the metal particle B is the same as that of Sn in the metal particle A. It is preferable that it is 0.6-21, More preferably, it is 0.8-9.5, and, as for the ratio (Cu content/Sn content) which occupies the content rate in the whole metal particle B, it is further more preferable that it is 1.0-5.6.

When the metal particle A contains Cu, the metal particle B contains Sn, and the average particle diameter of the metal particle A is 2 μm to 8 μm, the ratio (Cu content rate/Sn content rate) is preferably 1.5 to 64, more preferably It is 20-50, More preferably, it is 25-40. If the ratio (Cu content/Sn content) is in the range of 25 to 64, there is a tendency that a sintered body having excellent volume resistivity and temperature cycle resistance can be formed. On the other hand, when the metal particle A contains Cu, the metal particle B contains Sn, and the average particle diameter of the metal particle A is 0.1 μm to 0.5 μm, the ratio (Cu content/Sn content) is preferably 0.6 to 2.0, more preferably 0.9 to 1.8, still more preferably 1.2 to 1.6. If the ratio (Cu content/Sn content) is in the range of 1.5 to 1.7, there is a tendency that a sintered body having excellent volume resistivity and temperature cycle resistance can be formed.

In addition, in a certain embodiment, the ratio (Cu content/Sn content) is preferably 1.6 to 64, more preferably 1.7 to 40, and still more preferably 1.8 to 21. If the ratio (Cu content/Sn content) is in the range of 1.6 to 64, there is a tendency that a sintered body having excellent volume resistivity and temperature cycle resistance can be formed. The reason is not clear, but it is estimated as follows. It is estimated that if the ratio (Cu content/Sn content) is in the range of 1.6 to 64, the content ratio of Cu in the whole of metal particles A and B on a mass basis is higher than that of Sn in metal particles A and The content of the metal particles B as a whole is sufficiently high. Therefore, when transient liquid phase sintering occurs between the metal particles A and the metal particles B, unreacted Sn components are unlikely to remain in the sintered body. Here, if transient liquid phase sintering occurs between the metal particle A and the metal particle B, a copper-tin alloy is generated around the copper, so the grain boundary diameter of the copper-tin alloy depends on the copper particle diameter. Assuming that there are many unreacted Sn components in the sintered body, when the sintered body is subjected to the temperature cycle test, the unreacted Sn components and the copper-tin alloy will diffuse mutually, and the grain boundaries of the copper-tin alloy will be bonded to each other. The grain boundary diameter of the tin alloy gradually increases, whereby voids are generated in the sintered body, and the filling rate of the metal in the sintered body decreases, which may cause an increase in the volume resistivity. By setting the ratio (Cu content rate/Sn content rate) in the range of 1.6 to 64, the residual amount of Sn in the sintered body is reduced. Therefore, the decrease in the metal filling rate in the sintered body is suppressed and the volume can be formed. A sintered body with excellent resistance to temperature cycle characteristics in electrical resistivity.

When the metal particle A contains Cu and the metal particle B contains Sn and Bi, the content of Cu in the whole of the metal particle A and the metal particle B is the same as that of Bi in the metal particle A and the metal particle B on a mass basis The ratio of the content ratio (Cu content/Bi content) in the whole of the content is preferably 1.1-44, more preferably 2.3-44, still more preferably 3-20, and particularly preferably 5-10. If the ratio (Cu content/Bi content) is 1.1 to 44, there is a tendency that a sintered body having excellent volume resistivity and temperature cycle resistance can be formed.

The ratio of metal particle B to metal particle A (metal particle B/metal particle A) on a mass basis is preferably 10/90 to 90/10, more preferably 20/80 to 80/20, and still more preferably 30/70 ~70/30.

The average particle diameters of the metal particles A and the metal particles B are not particularly limited. For example, in a certain embodiment, the average particle diameter of the metal particles A and the metal particles B may be 0.1 μm-10 μm, respectively, may be 1 μm-5 μm, or may be 2 μm-3 μm. In addition, in a certain embodiment, the average particle diameter of the metal particles A is preferably 0.05 μm to 10 μm, more preferably 0.1 μm to 2 μm, and still more preferably 0.15 μm to 1 μm. In particular, since the average particle diameter of the metal particles A is 2 μm or less, after the transient liquid phase sintering, the amount of the metal particles A that have not undergone liquid phase sintering can be reduced. As a result, it is possible to suitably reduce the electromagnetic wave shielding effect. The tendency of the volume resistivity of the sintered body. In addition, in an embodiment, from the viewpoint of the metal filling rate in the electromagnetic wave shielding composition, the average particle diameter of the metal particles B is preferably 0.01 μm to 4 μm, more preferably 0.05 μm to 1 μm or 2 μm～3 μm.

Furthermore, in a certain embodiment, from the viewpoint of further reducing the volume resistivity of the sintered body for electromagnetic wave shielding described later, the average particle diameter of the metal particles A is preferably 0.2 μm or more, more preferably 0.8 μm or more, and still more preferably It is 2 μm or more. In addition, from the viewpoint of improving the surface smoothness of the sintered body for electromagnetic wave shielding described later, the average particle diameter of the metal particles A is preferably 2 μm or less, more preferably 1 μm or less, and still more preferably 0.8 μm or less.

The relationship between the sizes of the metal particles A and the metal particles B is not particularly limited. In order to easily form a sintered body of the metal particles A and the metal particles B, it is preferable to pack the metal particles A and the metal particles B as densely as possible before sintering. Therefore, for example, the value of the average particle diameter of the metal particle A/the average particle diameter of the metal particle B is preferably greater than 1, more preferably greater than 1.1, and still more preferably greater than 1.2. The upper limit of the value of the average particle diameter of the metal particle A/the average particle diameter of the metal particle B is not particularly limited, and for example, it may be 3 or less.

In addition, in a certain embodiment, the average particle diameter of metal particle A may be 10 μm-50 μm, the average particle diameter of metal particle B may be 5 μm-30 μm, and the average particle diameter of metal particle A/metal particle B The value of the average particle diameter exceeds 1 and is 10 or less. In addition, in a certain embodiment, the average particle diameter of metal particle A may be 0.01 μm-10 μm, the average particle diameter of metal particle B may be 5 μm-30 μm, and the average particle diameter of metal particle A/metal particle B may be The value of the average particle diameter is 0.002 or more and less than 1. In addition, in a certain embodiment, the average particle diameter of metal particle A may be 4 μm-10 μm, the average particle diameter of metal particle B may be 3 μm-10 μm, and the average particle diameter of metal particle A/metal particle B may be The value of the average particle diameter is 0.5-2. In addition, in an embodiment, the average particle diameter of metal particle A may be 0.01 μm-10 μm, the average particle diameter of metal particle B may be 0.01 μm-5 μm, and the average particle diameter of metal particle A/metal particle B The value of the average particle diameter is 0.05-2.

The average particle diameter of metal particles refers to a laser diffraction particle size distribution meter (for example, Beckman-Coulter Co., Ltd., LS 13 320 laser scattering diffraction method particle size distribution measuring device ) The measured volume average particle diameter. Specifically, in 125 g of a solvent (terpineol), metal particles are added in the range of 0.01% by mass to 0.3% by mass to prepare a dispersion. About 100 ml of this dispersion liquid is poured into a cell, and it measures at 25 degreeC. The particle size distribution is measured by setting the refractive index of the solvent to 1.48.

The total content of the metal particles A and the metal particles B in the electromagnetic wave shielding composition is not particularly limited. For example, the total ratio of the metal particles A and the metal particles B to the total solid content of the electromagnetic wave shielding composition on a mass basis is preferably 96% by mass or less, more preferably 95% by mass or less, and still more preferably 94 Less than mass%. In addition, the total ratio of the metal particles A and the metal particles B to the entire solid content of the electromagnetic wave shielding composition on a mass basis may be 65% by mass or more.

The total content of the metal particles A and the metal particles B in the electromagnetic wave shielding composition is not particularly limited. For example, the total ratio on a mass basis of the metal particles A and the metal particles B in the entire electromagnetic wave shielding composition is preferably 96% by mass or less, more preferably 95% by mass or less, and still more preferably 94% by mass or less . In addition, the total ratio of the metal particles A and the metal particles B in the entire electromagnetic wave shielding composition on a mass basis may be 65% by mass or more.

(Resin) The electromagnetic wave shielding composition of the present disclosure contains resin. When the electromagnetic wave shielding composition contains a resin, the voids in the sintered body of the metal particles A and the metal particles B are filled with the resin, and the stress relaxation properties and adhesiveness tend to be improved.

The resin contained in the electromagnetic wave shielding composition may be a thermoplastic resin, a thermosetting resin, or a combination of these. In addition, the resin may be in the state of a monomer having a functional group capable of generating a polymerization reaction by heating, or may be in the state of a polymer that has already been polymerized.

From the viewpoint of heat resistance, the electromagnetic wave shielding composition preferably contains a thermosetting resin as the resin. Examples of thermosetting resins include epoxy groups, acrylic groups, methacrylic groups, hydroxyl groups, vinyl groups, carboxyl groups, amino groups, maleimide groups, acid anhydride groups, thiol groups, and sulfinyl groups. Resins with functional groups such as groups.

Specific examples of thermosetting resins include epoxy resins, oxazine resins, bismaleimide resins, phenol resins, unsaturated polyester resins, and silicone resins. Among these, epoxy resin is preferred.

Specific examples of epoxy resins include, for example, bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, phenol novolac type epoxy resins, and cresol novolac type epoxy resins. Oxygen resin, naphthalene type epoxy resin, biphenol type epoxy resin, biphenyl novolac type epoxy resin and cycloaliphatic epoxy resin. A resin component may be used individually by 1 type, and may use 2 or more types together.

The content of the resin in the electromagnetic wave shielding composition is not particularly limited. For example, the proportion of the resin in the total solid content of the electromagnetic wave shielding composition is preferably 0.1% by mass to 50% by mass, more preferably 0.5% by mass to 30% by mass, and still more preferably 1% by mass to 15% by mass . In addition, the proportion of the resin in the solid content of the electromagnetic wave shielding composition other than the metal particles A and the metal particles B is preferably 10% by mass to 90% by mass, more preferably 20% by mass to 80% by mass, and further Preferably, it is 30% by mass to 70% by mass.

The content of the resin in the electromagnetic wave shielding composition is not particularly limited. For example, the proportion of the resin in the entire electromagnetic wave shielding composition is preferably 0.1% by mass to 5% by mass, more preferably 0.2% by mass to 3% by mass, and still more preferably 0.3% by mass to 1% by mass. In addition, the proportion of the resin in the electromagnetic wave shielding composition other than the metal particles A and the metal particles B is preferably 0.5% by mass to 10% by mass, more preferably 0.8% by mass to 5% by mass, and still more preferably 1 Mass% to 3% by mass.

(hardener) When the resin is a thermosetting resin, the electromagnetic wave shielding composition may contain a curing agent that hardens the thermosetting resin. The kind of hardening agent is not specifically limited, According to the kind of thermosetting resin, it can select suitably.

When the thermosetting resin is an epoxy resin, examples of the curing agent include amine curing agents, phenol curing agents, acid anhydride curing agents, and the like. The curing agent may be a liquid curing agent or a solid curing agent. The hardener may be used singly, or two or more of them may be used in combination.

Examples of the amine-based curing agent include chain aliphatic amines, cyclic aliphatic amines, aliphatic aromatic amines, and aromatic amines. Specific examples of the amine curing agent include: m-phenylenediamine, 1,3-diaminotoluene, 1,4-diaminotoluene, 2,4-diaminotoluene, 3,5-diaminotoluene, and 3,5-diaminotoluene. Ethyl-2,4-diaminotoluene, 3,5-diethyl-2,6-diaminotoluene, 2,4-diaminoanisole and other aromatic amine hardening Agent; 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 4,4'-methylenebis(2-ethylaniline), 3,3'- Diethyl-4,4'-diaminodiphenylmethane, 3,3',5,5'-tetramethyl-4,4'-diaminodiphenylmethane, 3,3',5 ,5'-tetraethyl-4,4'-diaminodiphenylmethane and other aromatic amine hardeners with two aromatic rings; the hydrolysis condensate of aromatic amine hardeners; polyoxytetramethylene two -Polytetramethylene oxide di-p-amino benzoic acid ester, polytetramethylene oxide di-p-amino benzoate, etc. have polyethers Structured aromatic amine hardener; condensate of aromatic diamine and epichlorohydrin; reaction product of aromatic diamine and styrene, etc.

Examples of acid anhydride hardeners include phthalic anhydride, maleic anhydride, methylbicycloheptene dicarboxylic acid anhydride, bicycloheptene dicarboxylic acid anhydride, succinic anhydride, tetrahydrophthalic anhydride, and hexahydrophthalic anhydride. Dicarboxylic anhydride, chloro-bridged acid anhydride, methyltetrahydrophthalic anhydride, 3-methylhexahydrophthalic anhydride, 4-methylhexahydrophthalic anhydride, trialkyltetrahydrophthalic anhydride Formic anhydride maleic acid adduct, benzophenone tetracarboxylic anhydride, trimellitic anhydride, pyromellitic anhydride, hydrogenated methyl nadic anhydride, from maleic anhydride and diene compounds and through Diels- Various cyclic anhydrides such as trialkyltetrahydrophthalic anhydride and dodecenyl succinic anhydride, which are obtained by Diels-Alder reaction and have multiple alkyl groups.

Examples of phenolic hardeners include those selected from phenol compounds (for example, phenol, cresol, xylenol, resorcinol, catechol, bisphenol A and bisphenol F) and naphthol compounds (for example, At least one of the group consisting of α-naphthol, β-naphthol, and dihydroxy naphthalene, and aldehyde compounds (for example, formaldehyde, acetaldehyde, propionaldehyde, benzaldehyde, and salicylaldehyde) in an acid catalyst Novolac resin obtained by condensation or co-condensation; phenol-aralkyl resin; biphenyl-aralkyl resin; naphthol-aralkyl resin, etc.

It is preferable to combine the equivalent number of the functional group of the hardener (for example, an amine group in the case of an amine hardener, a phenolic hydroxyl group in the case of a phenolic hardener, and an acid anhydride group in the case of an acid anhydride hardener) with the epoxy resin The ratio of the number of equivalents (the number of equivalents of the curing agent/the number of equivalents of the epoxy resin) is set in the range of 0.6 to 1.4, more preferably in the range of 0.7 to 1.3, and still more preferably in the range of 0.8 to 1.2.

(Hardening accelerator) When the electromagnetic wave shielding composition contains a thermosetting resin, the electromagnetic wave shielding composition may contain a curing accelerator that promotes the curing reaction of the thermosetting resin or the curing reaction of the thermosetting resin and the curing agent. The kind of hardening accelerator is not specifically limited, According to the kind of thermosetting resin and hardening agent, it can select suitably.

Specific examples of the hardening accelerator include: 1,8-diaza-bicyclo[5.4.0]undecene-7, 1,5-diaza-bicyclo[4.3.0]nonene, 5 ,6-Dibutylamino-1,8-diaza-bicyclo[5.4.0]undecene-7 and other cyclic amidine compounds; p-cyclic amidine compounds add maleic anhydride, 1,4-benzoquinone, 2,5-methylbenzoquinone, 1,4-naphthoquinone, 2,3-dimethylbenzoquinone, 2,6-dimethylbenzoquinone, 2,3-dimethoxy-5-methyl-1, Quinone compounds such as 4-benzoquinone, 2,3-dimethoxy-1,4-benzoquinone, phenyl-1,4-benzoquinone, diazophenylmethane, phenol resins and other compounds with π bonds Compounds with intramolecular polarization; tertiary amine compounds such as benzyldimethylamine, triethanolamine, dimethylaminoethanol, tris(dimethylaminomethyl)phenol; derivatives of tertiary amine compounds ; Imidazole, 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole and other imidazole compounds; derivatives of imidazole compounds; tetraphenylphosphonium tetraphenyl borate, triphenylphosphonium tetra Tetraphenyl borate such as phenyl borate, 2-ethyl-4-methylimidazolium tetraphenyl borate, N-methylmorpholinium tetraphenyl borate; derivatives of tetraphenyl borate; Triphenylborane complexes such as triphenylphosphine-triphenylborane complexes, morpholine-triphenylborane complexes, etc. One type of hardening accelerator may be used alone, or two or more types may be used in combination.

The content of the curing accelerator is preferably 0.1% by mass to 15% by mass relative to the total amount of the thermosetting resin and the curing agent.

(Flux composition) The electromagnetic wave shielding composition of the present disclosure may also contain a flux component. In the present disclosure, the so-called flux component refers to an organic compound that can exert a fluxing effect (a removal effect of an oxide film), and the type thereof is not particularly limited. The flux component can also function as a curing agent for epoxy resin, which is a thermosetting resin. In the present disclosure, a component that functions both as a flux component and also as a hardening agent for epoxy resin is referred to as a flux component. Specific examples of flux components include rosin, activating agents, thixotropic agents, and antioxidants. One type of flux component may be used alone, or two or more types may be used in combination.

As the rosin, specifically, dehydropinpinic acid, dihydropinpinic acid, neopinpinic acid, dihydropimaric acid, pimaric acid, isopimaric acid, tetrahydropinpinic acid, palustric acid, 2,2-bis(hydroxymethyl)propionic acid (2,2-bis(hydroxymethyl)propionic acid, BHPA), etc. Specific examples of the active agent include: aminodecanoic acid, pentane-1,5-dicarboxylic acid, triethanolamine, diethanolamine, ethanolamine diphenylacetic acid, sebacic acid, phthalic acid, benzoic acid , Dibromosalicylic acid, anisic acid, iodosalicylic acid, picolinic acid, propionic acid, 4-aminosalicylic acid, 3-(benzylamino) ethyl propionate, etc. Specific examples of the thixotropic agent include: 12-hydroxystearic acid, 12-hydroxystearic acid triglyceride, ethylene distearate amide, hexamethylene bisoleate amide, N,N '-Distearyl adipamide and so on. Specific examples of the antioxidant include hindered phenol-based antioxidants, phosphorus-based antioxidants, and hydroxylamine-based antioxidants.

When the composition for electromagnetic wave shielding contains a flux component, in a certain embodiment, as a flux component, it is preferable to contain at least one of rosin and an activating agent. In this case, it is preferable that the rosin contains BHPA and the active agent contains triethanolamine. As the flux component, it is more preferable to use BHPA and triethanolamine in combination.

When the electromagnetic wave shielding composition contains a flux component, in a certain embodiment, it is preferable to set the temperature at which the flux component changes phase to α (°C) and the melting point of the metal particles B to β ( ℃), it contains a flux component (specific flux component) that satisfies β-20≦α≦β+20. By using an electromagnetic wave shielding composition containing a specific flux component, there is a tendency that oxidation of the sintered body surface during sintering at a low temperature in an atmospheric environment can be suppressed.

The reason why the oxidation of the surface of the sintered body during sintering in an atmospheric environment can be suppressed by using a specific flux component as the flux component is not clear, but it is estimated as follows. It is presumed that the reason is that when transient liquid phase sintering occurs between the metal particle A and the metal particle B, the specific flux component becomes an active state near the melting point of the metal particle B. Therefore, the oxidation of the surface of the sintered body can be efficiently suppressed at a temperature at which transient liquid phase sintering can be performed, and the oxidation of the surface of the sintered body can be suppressed. In addition, in the present disclosure, "the temperature at which the flux component undergoes a phase change" refers to the temperature at which the flux component changes from a liquid to a gas, from a solid to a liquid, or the like. For example, "the temperature at which the flux component undergoes a phase change" may be the melting point of the flux component or the boiling point of the flux component.

Furthermore, when reliability tests such as high-temperature and high-humidity tests are performed on a sintered body obtained by using an electromagnetic wave shielding composition containing a specific flux component, it is possible to suppress deterioration of characteristics such as increase in volume resistivity, etc. The tendency of deterioration of appearance.

Since the specific flux composition satisfies α≦β+20, the temperature at which the specific flux composition undergoes phase transition does not become too high relative to the melting point of the metal particles B. When transient liquid phase sintering is performed at a low temperature, the specific auxiliary flux The flux becomes active, and there is a tendency to efficiently suppress oxidation on the surface of the sintered body.

In addition, since the specific flux component satisfies β-20≦α, the temperature at which the specific flux component undergoes phase transition does not become too low relative to the melting point of the metal particle B, and the electromagnetic wave shielding composition has excellent storage properties and can be While suppressing adverse effects on the production of the sintered body, the tendency of the surface of the sintered body to be oxidized during sintering in an air environment can be appropriately suppressed.

The specific flux composition can satisfy α≦β+15 or α≦β+10. The specific flux composition can satisfy β-10≦α, or β≦α.

As a specific flux component, specifically, the component which satisfies β-20≦α≦β+20 among rosin, activator, thixotropic agent, and antioxidant. A specific flux component may be used individually by 1 type, and may use 2 or more types together. For example, as the specific flux component, it may be appropriately selected from rosin, activator, thixotropic agent, antioxidant, etc., based on the relationship between the melting point of the metal particles B and the temperature at which the specific flux component undergoes phase change.

The temperature at which the phase transition of the specific flux component occurs is preferably 130°C to 160°C, and more preferably 135°C to 155°C, for example.

The specific flux component is preferably at least one selected from the group consisting of propionic acid, 4-aminosalicylic acid, and ethyl 3-(benzylamino)propionate.

When the electromagnetic wave shielding composition contains a flux component, the ratio of the flux component to the entire solid content of the electromagnetic wave shielding composition is preferably, for example, 0.1% by mass to 50% by mass, more preferably 0.5% by mass ~40% by mass, more preferably 1% by mass to 30% by mass. The ratio of the flux component to the solid content of the electromagnetic wave shielding composition other than the metal particles A and the metal particles B is preferably 5 mass% to 60 mass%, more preferably 10 mass% to 50 mass%, and further It is preferably 15% by mass to 40% by mass.

When the electromagnetic wave shielding composition contains a specific flux component, the ratio of the specific flux component to the entire electromagnetic wave shielding composition is preferably, for example, 1% by mass to 20% by mass, and more preferably 3% by mass to 15% by mass, more preferably 4% by mass to 10% by mass. When the electromagnetic wave shielding composition contains a specific flux component, the ratio of the specific flux component in the electromagnetic wave shielding composition excluding metal particles A and metal particles B is preferably 5 mass% to 70 mass% , More preferably 10% by mass to 50% by mass, and still more preferably 15% by mass to 30% by mass.

When the electromagnetic wave shielding composition contains a specific flux component, the electromagnetic wave shielding composition may contain the specific flux component and at the same time include a flux component that does not satisfy β-20≦α≦β+20 (hereinafter, also referred to as It is "other flux components"), and other flux components may not be included.

Other flux components are determined by the relationship with the melting point of the metal particles B, and specifically, can be selected from the specific examples of rosin, activator, thixotropic agent, and antioxidant.

When the electromagnetic wave shielding composition contains a specific flux component, in the electromagnetic wave shielding composition, the ratio of other flux components in the total of the specific flux component and other flux components may be 80% by mass or less. It can be 50% by mass or less.

(Solvent) The electromagnetic wave shielding composition of the present disclosure may also contain a solvent. From the viewpoint of sufficiently dissolving the resin, the solvent is preferably a polar solvent, and from the viewpoint of suppressing drying of the electromagnetic wave shielding composition in the step of providing the electromagnetic wave shielding composition, it is preferably one having a boiling point of 200° C. or higher The solvent is more preferably a solvent having a boiling point of 300°C or less from the viewpoint of suppressing the generation of voids during sintering.

Examples of solvents include: terpineol, stearyl alcohol, tripropylene glycol methyl ether, diethylene glycol, diethylene glycol monoethyl ether (alias, ethoxyethoxyethanol), diethylene glycol mono Hexyl ether (alias: hexyl carbitol), diethylene glycol monomethyl ether, dipropylene glycol-n-propyl ether, dipropylene glycol-n-butyl ether, tripropylene glycol-n-butyl ether, 1,3-butanediol, 1, Alcohols such as 4-butanediol, propylene glycol phenyl ether, 2-(2-butoxyethoxy) ethanol; tributyl citrate, 4-methyl-1,3-dioxolane- 2-ketone, γ-butyrolactone, diethylene glycol monoethyl ether acetate, dipropylene glycol methyl ether acetate, diethylene glycol monobutyl ether acetate, glycerol triacetate and other esters; isophores Ketones such as ketone; N-methyl-2-pyrrolidone and other internal amines; nitriles such as phenylacetonitrile, etc. One type of solvent may be used alone, or two or more types may be used in combination.

The ratio of the solvent in the electromagnetic wave shielding composition is preferably such that the electromagnetic wave shielding composition has a viscosity suitable for imparting methods such as a screen printing method and a spray coating method. Regarding the ratio of the solvent in the electromagnetic wave shielding composition, in a certain embodiment, relative to the entire electromagnetic wave shielding composition, for example, it is preferably 0.1% by mass to 50% by mass, and more preferably 0.5% by mass to 30% by mass. , More preferably 1% by mass to 10% by mass. Regarding the ratio of the solvent in the electromagnetic wave shielding composition, in a certain embodiment, with respect to the entire electromagnetic wave shielding composition, for example, it is preferably 0.1% by mass to 25% by mass, and more preferably 0.2% by mass to 20% by mass. , More preferably 0.3% by mass to 15% by mass.

(Method of manufacturing electromagnetic wave shielding composition) The manufacturing method of the electromagnetic wave shielding composition of this indication is not specifically limited. It can be obtained by mixing the components constituting the electromagnetic wave shielding composition, and then performing processing such as stirring, dissolving, and dispersing. The device used for these mixing, stirring, dispersing, etc. is not particularly limited, and three roll mills, planetary mixers, planetary mixers, rotation and rotation mixers, crushers, twin-shaft kneaders, etc. can be used. Thin-layer shearing and dispersing machine, etc. In addition, these devices may be appropriately combined and used. During the treatment, heating may be performed as needed. After the treatment, the maximum particle diameter of the electromagnetic wave shielding composition can also be adjusted by filtering. Filtration can be performed using a filtration device. As a filter for filtration, a metal mesh, a metal filter, and a nylon mesh are mentioned, for example.

＜Sheet for electromagnetic wave shielding＞ The electromagnetic wave shielding sheet of the present disclosure has a resin composition layer containing the electromagnetic wave shielding composition of the present disclosure. If necessary, the electromagnetic wave shielding sheet of this disclosure may further include a mold release film, and may be comprised.

The resin composition layer can be produced, for example, by applying a varnish-like electromagnetic wave shielding composition (hereinafter, also referred to as "resin varnish") prepared by adding a solvent to the electromagnetic wave shielding composition of the present disclosure. Polyethylene terephthalate film, polyimide film and other release films, and dried.

The application of the resin varnish can be implemented by a known method. Specifically, methods such as chipping wheel coating, die coating, die lip coating, gravure coating, stencil coating, spray coating, etc.; methods using an applicator, etc. can be cited. As a method of applying the resin varnish for forming the resin composition layer with a predetermined thickness, there can be mentioned: a cut-off wheel coating method in which the object to be coated passes through a gap, and die coating of a resin varnish with a flow rate adjusted from a nozzle. Bufa and so on. When the thickness of the resin composition layer before drying is 50 μm to 500 μm, it is preferable to use the chamfered wheel coating method.

The drying method is not particularly limited as long as at least a part of the solvent contained in the resin varnish can be removed, and it can be appropriately selected from drying methods generally used. The drying method may use drying by standing at room temperature (for example, 25° C.), heat drying, or reduced pressure drying. Heating drying or decompression drying can use heating plate, warm air dryer, warm air heating furnace, nitrogen dryer, infrared dryer, infrared heating furnace, far infrared heating furnace, microwave heating device, laser heating device, electromagnetic heating device , Heater heating device, steam heating furnace, etc. The temperature and time for drying can be appropriately adjusted according to the type and amount of the solvent used. For example, drying is preferably at 40°C to 180°C for 1 minute to 120 minutes.

The average thickness of the resin composition layer is preferably 3 μm to 300 μm, more preferably 5 μm to 100 μm, and still more preferably 10 μm to 50 μm.

＜Sintered body for electromagnetic wave shielding＞ The sintered body for electromagnetic wave shielding of this disclosure is a sintered body of the electromagnetic wave shielding composition of this disclosure or the electromagnetic wave shielding sheet of this disclosure. The shape of the sintered body for electromagnetic wave shielding is not particularly limited, and may be in the form of a layer provided on the support member, or may be in the form of a sheet.

The sintered body for electromagnetic wave shielding of the present disclosure can be manufactured by heating the electromagnetic wave shielding composition of the present disclosure or the electromagnetic wave shielding sheet of the present disclosure, so that the metal particles A and the metal contained in the electromagnetic wave shielding composition are heated. Particle B undergoes transient liquid phase sintering. Transient liquid phase sintering may be performed by heat treatment, or may be performed by heat and pressure treatment. Heating treatment can use heating plate, warm air dryer, warm air heating furnace, nitrogen dryer, infrared dryer, infrared heating furnace, far infrared heating furnace, microwave heating device, laser heating device, electromagnetic heating device, heater heating Equipment, steam heating furnace, etc. In addition, a hot plate pressing device or the like may be used for the heat and pressure treatment, or the heat treatment may be performed while applying pressure. The heating temperature in transient liquid phase sintering depends on the type of metal particles, and is preferably 140°C or higher, more preferably 190°C or higher, and still more preferably 220°C or higher. The upper limit of this heating temperature is not specifically limited, For example, it is 300 degrees C or less. The heating time in transient liquid phase sintering depends on the type of metal particles, and is preferably 5 seconds to 10 hours, more preferably 1 minute to 30 minutes, and still more preferably 3 minutes to 10 minutes. The transient liquid phase sintering is preferably performed in an environment with a low oxygen concentration. The term "low oxygen concentration environment" refers to a state where the volume-based oxygen concentration is 1000 ppm or less, preferably 500 ppm or less. In the case where the electromagnetic wave shielding composition contains a specific flux component as the flux component, the transient liquid phase sintering can be performed in a low oxygen concentration environment or in an atmospheric environment. By using the electromagnetic wave shielding composition of the present disclosure or the electromagnetic wave shielding sheet of the present disclosure containing a specific flux component to form the electromagnetic wave shielding sintered body of the present disclosure, there are those that perform transient liquid phase sintering even in an atmospheric environment In this case, the tendency of surface oxidation can also be suppressed.

The volume resistivity of the sintered body for electromagnetic wave shielding is preferably 3×10 ^-4 Ω·cm or less, more preferably 9×10 ^-5 Ω·cm or less, and still more ^{preferably 8×10 -5} Ω·cm or less, particularly preferably It is 7×10 ^-5 Ω·cm or less. The volume resistivity of the sintered body for electromagnetic wave shielding may be 1×10 ^-5 Ω·cm or more. In this disclosure, the volume resistivity refers to the value measured by the following method. Cut out a regular quadrilateral plate sample with a length of 15 mm on one side from the sheet-shaped sintered body for electromagnetic wave shielding, and press the high-precision resistivity meter Loresta-GP (Nitto Seiko analysis technology) on the center of the plate-shaped sample. (Manufactured by Nittoseiko analytech) Co., Ltd.) 4 probes. The volume resistivity ρ (Ω·cm) is obtained from the obtained surface resistivity and film thickness. In this disclosure, five plate-shaped samples are measured, and the average value thereof is used as the volume resistivity of the sintered body for electromagnetic wave shielding.

When the sintered body for electromagnetic wave shielding is layered or sheet-like, the average thickness of the sintered body for electromagnetic wave shielding is preferably 3 μm-30 μm, more preferably 4 μm-20 μm, and still more preferably 5 μm-10 μm .

＜Electronic component device＞ The electronic component device of the present disclosure has an area covered by the sintered body for electromagnetic wave shielding of the present disclosure. Examples of electronic component devices include: lead frames, wiring-completed tape carriers, wiring boards, glass, silicon wafers, and other supporting members, mounted with semiconductor chips, transistors, diodes, thyristors, and other active components, capacitors , Resistors, resistor arrays, coils, switches and other passive components and other electronic components. By using the electromagnetic wave shielding sintered body of the present disclosure to cover the locations where electromagnetic waves are generated or the locations that are susceptible to electromagnetic waves in the electronic component and the supporting member, the electronic component device of the present disclosure can be obtained. As a method of covering an electronic component or a supporting member with a sintered body for electromagnetic wave shielding, a method of applying a varnish-like electromagnetic wave shielding composition to a site to be covered with the sintered body for electromagnetic wave shielding, drying and heating is exemplified. As an application method, a screen printing method, a spray coating method, etc. are mentioned. The drying conditions and the drying method are the same as those at the time of manufacturing the electromagnetic wave shielding sheet. In addition, the heating conditions and the heating method are the same as those when the sintered body for electromagnetic wave shielding is manufactured. In addition, a method of arranging the electromagnetic wave shielding sheet of the present disclosure on a site to be covered with the sintered body for electromagnetic wave shielding, and heating it. The heating conditions and heating method of the electromagnetic wave shielding sheet are the same as the conditions and methods when the sintered body for electromagnetic wave shielding is manufactured.

The electronic component device of the present disclosure may also include: a support member, an electronic component arranged on the support member, a hardened material of a sealing material that seals the electronic component, and the electromagnetic wave shielding sintering of the present disclosure arranged on the surface of the hardened material of the sealing material body. When the sintered body for electromagnetic wave shielding is arranged on the surface of the hardened material of the sealing material, the sintered body for electromagnetic wave shielding can be formed on the surface of the hardened material of the sealing material after the sealing material is hardened. An electromagnetic wave shielding composition or an electromagnetic wave shielding sheet is arranged on the surface, and the sealing material is cured and the electromagnetic wave shielding sintered body is formed together.

The electronic component device may further include a frame for accommodating the electronic component and the supporting member. When the electronic component and the supporting member are contained in the housing, the electronic component device of the present disclosure can be obtained by covering at least one of the inner surface and the outer surface of the housing with the sintered body for electromagnetic wave shielding of the present disclosure. The method of covering the inner or outer surface of the frame with the sintered body for electromagnetic wave shielding is the same as the method of covering the electronic parts or supporting members with the sintered body for electromagnetic wave shielding.

In the area covered by the electromagnetic wave shielding sintered body of the electronic component device, from the standpoint of adhesive strength, it is preferable to use electronic parts, support members, frames, etc., which are covered by the electromagnetic wave shielding sintered body (coating member) No voids such as voids are generated in the interface with the sintered body for electromagnetic wave shielding. In the present disclosure, in the area covered by the sintered body for electromagnetic wave shielding, when the interface between the covering member and the sintered body for electromagnetic wave shielding is observed, the length of the portion where the covering member and the sintered body for electromagnetic wave shielding are not adhered is greater than that in the observation area The ratio of the length of the interface (hereinafter, referred to as porosity) is preferably 5% or less, more preferably 3% or less, and still more preferably 1% or less. The length of the interface in the observation area, and the length of the interface between the covering member and the sintered body for electromagnetic wave shielding that are not bonded to the sintered body for electromagnetic wave shielding occupies the following image, that is, using a scanning electron microscope (Scanning Electron Microscope, SEM) The image obtained by photographing the cross section of the area covered by the sintered body for electromagnetic wave shielding under the condition of 3000 times. [Example]

Hereinafter, the present disclosure will be explained in more detail through examples, but the present disclosure is not limited to the following examples.

[Example 1A] 61 parts by mass of Cu particles (product name: 1400YM, Mitsui Metals Mining Co., Ltd., average particle diameter: 4 μm) as metal particles A, and Sn-Bi58 particles (product name: STC-3, Mitsui Metals Mining) as metal particles B Co., Ltd., average particle size: 3 μm) 30 parts by mass, 4 parts by mass of epoxy resin as resin, 0.7 parts by mass of BHPA as rosin, 1.8 parts by mass of triethanolamine as activator, and 0.2 parts by mass of imidazole as hardening accelerator Parts by mass and 2.3 parts by mass of hexylcarbitol as a solvent were mixed to prepare resin varnish 1A. The resin varnish 1A was coated on the polyimide film using an applicator whose gap was set to 50 μm to produce a coating film. Thereafter, it was dried at 100°C for 30 minutes, and heat-treated at 150°C for 10 minutes in a reflow furnace in a nitrogen atmosphere to obtain a sintered body. The average thickness of the sintered body is 15 μm. A part of this sintered body was joined to a ground to form a test piece.

[Example 2A] 30 parts by mass of Cu particles (product name: CH-0200, Mitsui Metal Mining Co., Ltd., average particle diameter: 0.2 μm) as metal particles A and Sn-Bi58 particles (product name: STC-3, Mitsui Metal Mining Co., Ltd., average particle diameter: 3 μm) 60 parts by mass, 4 parts by mass of epoxy resin as resin, 0.7 parts by mass of BHPA as rosin, 2.8 parts by mass of triethanolamine as activator, and hardening accelerator 0.2 parts by mass of imidazole and 2.3 parts by mass of hexylcarbitol as a solvent were mixed to prepare resin varnish 2A. The resin varnish 2A was coated on the polyimide film with an applicator whose gap was set to 10 μm to produce a coating film. Thereafter, it was dried at 100°C for 30 minutes, and heat-treated at 150°C for 10 minutes in a reflow furnace in a nitrogen atmosphere to obtain a sintered body. The average thickness of the sintered body was 9 μm. A part of this sintered body was joined to the base to form a test piece.

[Example 3A] 21 parts by mass of Cu particles (product name: CH-0200, Mitsui Metal Mining Co., Ltd., average particle diameter: 0.2 μm) as the metal particle A, and Sn particles (product name: Sn100, STC-3) as the first metal particle B , Mitsui Metal Mining Co., Ltd., average particle diameter: 3 μm) 34 parts by mass, Sn-Bi58 particles as the second metal particle B (product name: SnBi58, STC-3, Mitsui Metal Mining Co., Ltd., average particle diameter: 3 μm) 34 parts by mass, 1.1 parts by mass of epoxy resin as resin, 2.0 parts by mass of BHPA as rosin, 7.5 parts by mass of triethanolamine as activator, 0.1 parts by mass of imidazole as hardening accelerator, and hexyl card as solvent 0.3 parts by mass of ethanol was mixed to prepare resin varnish 3A. The resin varnish 3A was coated on the polyimide film using an applicator whose gap was set to 50 μm to produce a coating film. Thereafter, it was dried at 100°C for 30 minutes, and heat-treated at 150°C for 10 minutes in a reflow furnace in a nitrogen atmosphere to obtain a sintered body. The average thickness of the sintered body was 15 μm. A part of this sintered body was joined to the base to form a test piece.

[Comparative Example 1] 61 parts by mass of silver-coated copper powder (product name: 1400YP, Mitsui Metals Mining Co., Ltd., average particle diameter: 10 μm) as metal particles, 32 parts by mass of epoxy resin as resin, and imidazole 4 as hardening accelerator Parts by mass and 230 parts by mass of butyl acetate as a solvent were mixed to prepare resin varnish 3. The resin varnish 3 was coated on the polyimide film using an applicator whose gap was set to 200 μm to produce a coating film. Then, it dried at 50 degreeC for 1 hour, and heat-processed at 150 degreeC for 1 hour, and obtained the sintered compact. The average thickness of the sintered body is 15 μm. A part of this sintered body was joined to the base to form a test piece.

＜Evaluation＞ (Measurement of electromagnetic wave shielding effect) The electromagnetic wave shielding effect was evaluated by the KEC method shown below. The obtained test piece was set in the measurement section of the electromagnetic wave shielding effect measuring device (KEC Kansai Electronics Industry Promotion Center), and the test piece was clamped and fixed from above and below. The device can generate both electromagnetic waves with large electric field components and electromagnetic waves with large magnetic field components. The electromagnetic wave shielding effect is evaluated based on the ratio of the intensity of the received electromagnetic wave when there is no test piece to the intensity of the received electromagnetic wave when the test piece is installed.

(Volume resistivity) With respect to the obtained sintered body, the volume resistivity was measured by the method described above in an environment of 25°C. The volume resistivity of the sintered body of Example 1A was 6×10 ^-5 Ω·cm, the volume resistivity of the sintered body of Example 2A was 9×10 ^-5 Ω·cm, and the volume resistivity of the sintered body of Example 3A It was 9×10 ^-5 Ω·cm, and the volume resistivity of the sintered body of Comparative Example 1 was 6×10 ^-4 Ω·cm.

FIG. 1 shows the measurement results of the electromagnetic wave shielding effect of the sintered bodies produced in Example 1A, Example 2A, and Comparative Example 1. As shown in FIG. It is found that the sintered body of the example in which the metal particles are sintered by TLPS can obtain a high electromagnetic wave shielding effect compared with the sintered body of Comparative Example 1.

[Example 1B] 19.5 parts by mass of Cu particles (product name: 1400YM, Mitsui Metal Mining Co., Ltd., average particle diameter: 4 μm) as metal particles A, and Sn-Bi58 particles (product name: STC-3, Mitsui Metals Mining) as metal particles B Co., Ltd., average particle diameter: 3 μm, melting point: 138°C) 54.3 parts by mass, epoxy resin 0.4 parts by mass as resin, and propionic acid (boiling point: 141°C) as flux component 4.4 parts by mass, as activator 9.0 parts by mass of triethanolamine (melting point: 20.5°C, boiling point: 335°C, (208°C at 20 hPa)), 0.1 parts by mass of imidazole as a hardening accelerator, and 12.3 parts by mass of hexyl carbitol as a solvent are mixed to produce Resin varnish 1B. The resin varnish 1B was coated on the polyimide film with an applicator whose gap was set to 50 μm to produce a coating film. Thereafter, it was dried at 100°C for 30 minutes, and heat-treated at 150°C for 10 minutes in a reflow furnace in an atmospheric environment to obtain a sintered body. The average thickness of the sintered body was 15 μm. A part of this sintered body was joined to the base to form a test piece. Furthermore, in Example 1B, since α (°C) is 141°C and β (°C) is 138°C, β-20≦α≦β+20 is satisfied.

[Example 2B] In Example 1B, except that the flux component was changed from propionic acid to 4-aminosalicylic acid (melting point: 150°C), a resin varnish 2B was produced in the same manner as in Example 1B, and then resin varnish 2B was used Obtain a sintered body and a test piece. Furthermore, in Example 2B, since α (°C) is 150°C and β (°C) is 138°C, β-20≦α≦β+20 is satisfied.

[Example 3B] In Example 1B, except that the flux component was changed from propionic acid to 2,2-bis(hydroxymethyl)propionic acid (BHPA, melting point: 185°C), a resin varnish 3B was produced in the same manner as in Example 1B. Then, the resin varnish 3B was used to obtain a sintered body and a test piece. Furthermore, in Example 3B, since α (°C) is 185°C and β (°C) is 138°C, β-20≦α≦β+20 is not satisfied.

(Appearance evaluation) The appearance of the obtained sintered body was visually confirmed. In the sintered bodies of Example 1B and Example 2B, the surface was gray, and oxidation of the surface was suppressed. On the other hand, in the sintered body of Example 3B, the surface was reddish brown, and compared with Example 1B and Example 2B, the surface was further oxidized.

(Measurement of volume resistivity) With respect to the obtained sintered body, the volume resistivity was measured by the method described above in an environment of 25°C. The results are shown in Table 1.

(Measurement of volume resistivity after high temperature and high humidity test) Cut out a 15 mm square plate-shaped sample from the sheet-shaped sintered body for electromagnetic wave shielding. Put the plate-shaped sample into a constant temperature and humidity bath at 85°C and 85%RH (relative humidity) and let it stand still. 100 hours. After that, the volume resistivity after the high-temperature and high-humidity test was measured in the same manner as described above (Measurement of Volume Resistivity). The results are shown in Table 1.

[Table 1] Example 1B Example 2B Example 3B Exterior gray gray Reddish brown Volume resistivity (Ω·cm) 5.7×10 ^-5 5.4×10 ^-5 5.6×10 ^-5 Volume resistivity after high temperature and high humidity test (Ω·cm) 5.7×10 ^-5 5.4×10 ^-5 1.8×10 ^-4 Appearance after high temperature and high humidity test gray gray Green cyan

As shown in Table 1, compared with the sintered body produced in Example 3B, the sintered bodies produced in Example 1B and Example 2B have suppressed surface oxidation. Furthermore, the volume resistivity of the sintered body produced in Example 1B and Example 2B and the sintered body produced in Example 3B were about the same when the high-temperature and high-humidity test was not performed. On the other hand, regarding the volume resistivity after the high-temperature and high-humidity test, the sintered body produced in Example 1B and Example 2B has a lower volume resistivity value than the sintered body produced in Example 3B, and the characteristics are Decrease is suppressed. Furthermore, when the electromagnetic wave shielding composition of Example 1B, Example 2B, and Example 3B was used for sintering treatment in a nitrogen atmosphere in the same manner as Example 1A, the products produced in Example 1B and Example 2B The sintered body has the same volume resistivity as the sintered body produced in Example 3B when the high-temperature and high-humidity test is not performed. Furthermore, the sintered body produced in Example 3B was the same as the sintered body produced in Example 1B and Example 2B, and oxidation of the surface was suppressed.

[Example 1C] 82.2 parts by mass of Cu particles (product name: 1400YM, Mitsui Metal Mining Co., Ltd., average particle diameter: 4 μm) as metal particle A, and Sn-Bi58 particles (product name: STC-3, Mitsui Metal Mining Co., Ltd.) as metal particle B Co., Ltd., average particle size: 3 μm) 17.8 parts by mass, 4 parts by mass of epoxy resin as resin, 0.7 parts by mass of BHPA as rosin, 2.8 parts by mass of triethanolamine as activator, and 0.2 parts by mass of imidazole as hardening accelerator Parts by mass and 2.3 parts by mass of hexylcarbitol as a solvent were mixed to prepare resin varnish 1C. The resin varnish 1C was coated on the polyimide film with an applicator whose gap was set to 50 μm to produce a coating film. Thereafter, it was dried at 100°C for 30 minutes, and heat-treated at 150°C for 10 minutes in a reflow furnace in a nitrogen atmosphere to obtain a sintered body. The average thickness of the sintered body was 15 μm. A part of this sintered body was joined to the base to form a test piece.

[Example 2C] 30 parts by mass of Cu particles (product name: 1400YM, Mitsui Metals Mining Co., Ltd., average particle diameter: 4 μm) as metal particles A, and Sn-Bi58 particles (product name: STC-3, Mitsui Metals Mining) as metal particles B Co., Ltd., average particle size: 3 μm) 60 parts by mass, 4 parts by mass of epoxy resin as resin, 0.3 parts by mass of BHPA as rosin, 2.8 parts by mass of triethanolamine as activator, and 0.2 parts by mass of imidazole as hardening accelerator Parts by mass and 2.3 parts by mass of hexylcarbitol as a solvent were mixed to prepare resin varnish 2C. The resin varnish 2C was coated on the polyimide film with an applicator whose gap was set to 50 μm to produce a coating film. Thereafter, it was dried at 100°C for 30 minutes, and heat-treated at 150°C for 10 minutes in a reflow furnace in a nitrogen atmosphere to obtain a sintered body. The average thickness of the sintered body is 15 μm. A part of this sintered body was joined to the base to form a test piece.

＜Evaluation＞ (Temperature cycle test) The prepared test piece was treated with a thermal cycle of -45°C to 125°C for 15 minutes each for 1000 cycles, and the method was used to determine the thermal cycle test before treatment (0 cycles), after 500 cycles, and 750 Volume resistivity at the time point after the cycle and after 1000 cycles. The obtained results are shown in Table 2.

[Table 2] 0 cycles After 500 cycles After 750 cycles After 1000 cycles Example 1C 2.5×10 ^-4 2.6×10 ^-4 2.5×10 ^-4 2.4×10 ^-4 Example 2C 1.3×10 ^-4 1.8×10 ^-4 3.0×10 ^-4 7.8×10 ^-4 The unit is Ω·cm

As is clear from Table 2, compared with the sintered body produced in Example 2C, the sintered body produced in Example 1C has an increase in volume resistivity due to an increase in the number of cycles of the temperature cycle test, and the volume resistivity is suppressed. The resistivity is excellent in temperature cycle resistance.

Regarding the disclosure of Japanese Patent Application No. 2019-177659 filed on September 27, 2019, and Japanese Patent Application No. 2020-101849 filed on June 11, 2020, the entirety is incorporated herein by reference. In the manual. Regarding all documents, patent applications, and technical specifications described in this specification, they are cited and incorporated to the same extent as the cases where each document, patent application, and technical specifications are specifically and individually described and incorporated by reference. Into this manual.

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Fig. 1 is a graph showing the measurement result of the electromagnetic wave shielding effect of the sintered body.

Claims (21)

An electromagnetic wave shielding composition containing metal particles A, metal particles B having a lower melting point than the metal particles A, and resin, and Between the metal particles A and the metal particles B, transient liquid phase sintering can be performed. The electromagnetic wave shielding composition according to claim 1, wherein the melting point of the metal particles B is 300°C or less. The electromagnetic wave shielding composition according to claim 1 or 2, wherein the metal particles A include Cu, and the metal particles B include Sn. The electromagnetic wave shielding composition according to claim 3, wherein the content ratio of Cu in the whole of the metal particles A and the metal particles B and the content of Sn in the metal particles A and the metal particles A on a mass basis The ratio (Cu content/Sn content) of the content ratio (Cu content ratio/Sn content ratio) occupied by the whole of the metal particles B is 0.6-21. The electromagnetic wave shielding composition according to claim 3, wherein the content ratio of Cu in the whole of the metal particles A and the metal particles B and the content of Sn in the metal particles A and the metal particles A on a mass basis The ratio of the content rate (Cu content rate/Sn content rate) occupied by the whole of the metal particles B is 1.6 to 64. The electromagnetic wave shielding composition according to any one of claims 3 to 5, wherein the metal particles B further include Bi, and On a mass basis, the ratio of the content rate of Cu in the entirety of the metal particles A and the metal particles B to the content rate of Bi in the entirety of the metal particles A and the metal particles B (Cu content rate/Bi content rate) is 1.1-44. The electromagnetic wave shielding composition according to any one of claims 1 to 6, wherein the total proportion of the metal particles A and the metal particles B in the entire solid content is 96% by mass or less. The electromagnetic wave shielding composition according to any one of claims 1 to 7, wherein the resin includes a thermosetting resin. The electromagnetic wave shielding composition according to claim 8 further contains a curing agent. The electromagnetic wave shielding composition according to Claim 8 or Claim 9 further contains a hardening accelerator. The electromagnetic wave shielding composition according to any one of claims 1 to 10 further contains a flux component. The electromagnetic wave shielding composition according to claim 11, wherein the flux component contains at least one of rosin and an active agent. The electromagnetic wave shielding composition according to claim 12, wherein the rosin contains 2,2-bis(hydroxymethyl)propionic acid, and the active agent contains triethanolamine. The electromagnetic wave shielding composition according to claim 11, wherein when the temperature at which the flux component undergoes a phase change is α (°C) and the melting point of the metal particles B is β (°C), The flux composition satisfies β-20≦α≦β+20. The electromagnetic wave shielding composition according to claim 14, wherein the temperature at which the flux component undergoes a phase change is 130°C to 160°C. The electromagnetic wave shielding composition according to claim 14 or claim 15, wherein the flux component is selected from propionic acid, 4-aminosalicylic acid and ethyl 3-(benzylamino)propionate. At least one of the formed groups. The electromagnetic wave shielding composition according to any one of claims 1 to 16 further contains a solvent. An electromagnetic wave shielding sheet having a resin composition layer containing the electromagnetic wave shielding composition according to any one of claims 1 to 17. A sintered body for electromagnetic wave shielding, which is a sintered body of the electromagnetic wave shielding composition according to any one of claims 1 to 17 or the electromagnetic wave shielding sheet according to claim 18. The sintered body for electromagnetic wave shielding according to claim 19, wherein the volume resistivity is 3×10 ^-4 Ω·cm or less. An electronic component device having an area covered by the sintered body for electromagnetic wave shielding as described in claim 19 or claim 20.

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