CN108140450B

CN108140450B - Metal-containing particle, connecting material, connection structure, and method for producing connection structure

Info

Publication number: CN108140450B
Application number: CN201780003651.8A
Authority: CN
Inventors: 笹平昌男; 土桥悠人
Original assignee: Sekisui Chemical Co Ltd
Current assignee: Sekisui Chemical Co Ltd
Priority date: 2016-03-15
Filing date: 2017-03-14
Publication date: 2021-08-03
Anticipated expiration: 2037-03-14
Also published as: JP7131908B2; KR20210154865A; JP2018009253A; JPWO2017159694A1; CN108140450A; KR20180120667A; WO2017159694A1; TW201800223A

Abstract

The invention provides a metal-containing particle, which can melt the front end of the protrusion of the metal part of the metal-containing particle at a lower temperature, solidify the metal-containing particle after melting and join with other particles or other components, and can improve the connection reliability. The metal-containing particle of the present invention comprises a base particle and a metal part disposed on the surface of the base particle, wherein the metal part has a plurality of protrusions on the outer surface, and the tips of the protrusions of the metal part can be melted at 400 ℃ or lower.

Description

Metal-containing particle, connecting material, connection structure, and method for producing connection structure

Technical Field

The present invention relates to a metal-containing particle including a base particle and a metal portion disposed on a surface of the base particle, the metal portion having a protrusion on an outer surface. The present invention also relates to a connecting material using the metal-containing particles, a connecting structure, and a method for producing a connecting structure.

Background

In electronic components and the like, a connecting material containing metal particles is sometimes used in order to form a connecting portion for connecting two members to be connected.

It is known that when the particle diameter of the metal particles is small to a size of 100nm or less and the number of constituent atoms is small, the surface area ratio to the volume of the particles increases rapidly, and the melting point or sintering temperature is greatly lowered as compared with the bulk state. A method is known in which metal particles having a particle diameter of 100nm or less are used as a connecting material by utilizing the low-temperature sintering performance, and the metal particles are sintered by heating to connect them. In this connection method, the metal particles after connection are changed into bulk metal, and connection by metal bonding is obtained at the connection interface, so that heat resistance, connection reliability, and heat radiation property are extremely high.

A connecting material for performing such connection is disclosed in, for example, patent document 1 below.

The connecting material described in patent document 1 includes composite silver particles of nanometer size, and a resin. The composite silver particles are particles in which an organic coating layer is formed around a silver core, which is an aggregate of silver atoms. The organic coating layer is formed of one or more alcohol components selected from the group consisting of a residue of an alcohol molecule having 10 or 12 carbon atoms, a derivative of an alcohol molecule (the derivative of an alcohol molecule is limited to a carboxylic acid and/or an aldehyde) and/or an alcohol molecule.

Patent document 2 discloses a connecting material containing nanosized metal-containing particles and conductive particles.

Documents of the prior art

Patent document

Patent document 1: japanese patent No. 5256281

Patent document 2: japanese laid-open patent publication No. 2013-55046

Disclosure of Invention

Technical problem to be solved by the invention

Metal particles such as nano-sized silver particles are fused and joined by heat treatment at the time of connection to form a mass. When the block is formed, the melting point is increased, and therefore, there is a problem that the heating temperature is increased. In addition, gaps are generated between the nano-sized particles in the formed bulk. As a result, the connection reliability becomes low.

In addition, in patent document 1, since the composite silver particles have an alcohol component on the surface, voids at the connecting portion derived from the alcohol component are easily generated. As a result, the connection reliability becomes low.

The purpose of the present invention is to provide metal-containing particles that can be joined to other particles or other members by melting the tips of metal protrusions of the metal-containing particles at a relatively low temperature and solidifying the melted metal protrusions, thereby improving the connection reliability. Another object of the present invention is to provide a connecting material using the metal-containing particles, a connecting structure, and a method for producing a connecting structure.

Technical solution for solving technical problem

According to a broad aspect of the present invention, there is provided a metal-containing particle comprising: the metal part has a plurality of protrusions on an outer surface thereof, and a tip of the protrusion of the metal part is capable of melting at 400 ℃ or lower.

In a specific aspect of the metal-containing particle of the present invention, the metal part has a plurality of convex portions on an outer surface, and the metal part has the protrusions on the outer surface of the convex portions.

In a specific aspect of the metal-containing particle of the present invention, a ratio of an average height of the convex portion to an average height of the protrusion is 5 or more and 1000 or less.

In a specific aspect of the metal-containing particle of the present invention, the average diameter of the base of the convex portion is 3nm or more and 5000nm or less.

In a specific aspect of the metal-containing particle of the present invention, the surface area of a portion where the convex portion is present is 10% or more of the total surface area 100% of the outer surface of the metal portion.

In a specific aspect of the metal-containing particle of the present invention, the shape of the convex portion is a needle shape or a shape of a part of a sphere.

In a specific aspect of the metal-containing particle of the present invention, the average value of the apex angle of the protrusions is 10 ° or more and 60 ° or less.

In a specific aspect of the metal-containing particle of the present invention, the average height of the protrusions is 3nm or more and 5000nm or less.

In a specific aspect of the metal-containing particle of the present invention, the average diameter of the base of the protrusion is 3nm or more and 1000nm or less.

In a specific aspect of the metal-containing particle of the present invention, a ratio of an average height of the protrusions to an average diameter of bases of the protrusions is 0.5 or more and 10 or less.

In a particular aspect of the metal-containing particle of the present invention, the protrusions are in the shape of needles or in the shape of a portion of a sphere.

In a particular aspect of the metal-containing particles of the invention, the material of the protrusions comprises silver, copper, gold, palladium, tin, indium or zinc.

In a specific aspect of the metal-containing particle of the present invention, the material of the metal portion is not solder.

In a specific aspect of the metal-containing particle of the present invention, the material of the metal part contains silver, copper, gold, palladium, tin, indium, zinc, nickel, cobalt, iron, tungsten, molybdenum, ruthenium, platinum, rhodium, iridium, phosphorus, or boron.

In a specific aspect of the metal-containing particle of the present invention, the tip of the protrusion of the metal part is preferably meltable at 350 ℃ or lower, more preferably at 300 ℃ or lower, even more preferably at 250 ℃ or lower, and particularly preferably at 200 ℃ or lower.

In a specific aspect of the metal-containing particle of the present invention, the compression modulus of elasticity at 10% compression is 100N/mm²Above 25000N/mm²The following.

In a particular aspect of the metal-containing particles of the present invention, the substrate particles are polysiloxane particles.

According to a broad aspect of the present invention, there is provided a connecting material comprising the metal-containing particles described above and a resin.

According to a broad aspect of the present invention, there is provided a connection structure comprising: a first connection target member, a second connection target member, and a connection portion for connecting the first connection target member and the second connection target member together, wherein a material of the connection portion is the metal-containing particle or the connection material containing the metal-containing particle and a resin.

According to a broad aspect of the present invention, there is provided a method of manufacturing a connection structure, comprising: disposing the metal-containing particles or the connecting material containing the metal-containing particles and the resin between the first connection target member and the second connection target member; and a step of heating the metal-containing particles to melt and solidify the tips of the protrusions of the metal part, and forming a connection portion for connecting the first connection target member and the second connection target member together using the metal-containing particles or the connection material.

ADVANTAGEOUS EFFECTS OF INVENTION

The metal-containing particle of the present invention comprises a base particle and a metal part disposed on the surface of the base particle, wherein the metal part has a plurality of protrusions on the outer surface, and the tips of the protrusions of the metal part can be melted at 400 ℃ or lower, so that the tips of the protrusions of the metal part of the metal-containing particle can be melted at a relatively low temperature and then solidified to be joined to other particles or other members, thereby improving the connection reliability.

Drawings

FIG. 1 is a cross-sectional view schematically illustrating a metal-containing particle according to a first embodiment of the present invention;

FIG. 2 is a cross-sectional view schematically illustrating a metal-containing particle according to a second embodiment of the present invention;

FIG. 3 is a cross-sectional view schematically illustrating a metal-containing particle according to a third embodiment of the present invention;

FIG. 4 is a cross-sectional view schematically illustrating a metal-containing particle according to a fourth embodiment of the present invention;

FIG. 5 is a cross-sectional view schematically illustrating a metal-containing particle according to a fifth embodiment of the present invention;

FIG. 6 is a cross-sectional view schematically illustrating a metal-containing particle according to a sixth embodiment of the present invention;

FIG. 7 is a cross-sectional view schematically showing a metal-containing particle according to a seventh embodiment of the present invention;

FIG. 8 is a cross-sectional view schematically showing a metal-containing particle according to an eighth embodiment of the present invention;

fig. 9 is a cross-sectional view schematically showing a connection structure using metal-containing particles according to a first embodiment of the present invention;

fig. 10 is a cross-sectional view schematically showing a modification of the connection structure using the metal-containing particles according to the first embodiment of the present invention;

FIG. 11 is a diagram showing an image of manufactured metal-containing particles;

FIG. 12 is a diagram showing an image of manufactured metal-containing particles;

FIG. 13 is a diagram showing an image of manufactured metal-containing particles;

FIG. 14 is a diagram showing an image of manufactured metal-containing particles;

FIG. 15 is a view showing an image of a particle obtained by melting and solidifying the distal ends of projections of a metal part of a metal-containing particle to be produced;

FIG. 16 is a view showing an image of a particle obtained by melting and solidifying the tip of a protrusion of a metal part of a metal-containing particle to be produced;

FIG. 17 is a view showing an image of a particle obtained by melting and solidifying the tip of a protrusion of a metal part of the produced metal-containing particle;

FIG. 18 is a view showing an image of a particle obtained by melting and solidifying the distal ends of the projections of the metal part of the produced metal-containing particle;

FIGS. 19(a) and (b) are a plan view and a cross-sectional view showing an example of a conduction check member;

fig. 20(a) to (c) are diagrams schematically showing a state in which the electrical characteristics of the electronic circuit device are inspected by the continuity inspecting member.

Description of the marks

1. 1A, 1B, 1C, 1D, 1E, 1F, 1G … Metal-containing particles

1a, 1Aa, 1Ba, 1Ca, 1Da, 1Ea, 1Fa, 1Ga … protrusions

2 … substrate particles

3. 3A, 3B, 3C, 3D, 3E, 3F, 3G … metal part (metal layer)

3a, 3Aa, 3Ba, 3Ca, 3Da, 3Ea, 3Fa, 3Ga … protrusions

3BX … Metal particles

3CA, 3GA … first metal part

3CB, 3GB … second metal part

3Da, 3Ea, 3Fa, 3Ga … convex parts

3Db, 3Eb, 3Fb, 3Gb … protrusions

4E … core material

11 … conduction check member

12 … matrix

12a … through hole

13 … conductive part

21 … conduction check member

22 … matrix

22a … through hole

23 … conductive part

31 … BGA substrate

31A … multilayer substrate

31B … solder ball

32 … current meter

51 … connection structure

52 … first connection object part

52a … first electrode

53 … second connection object part

53a … second electrode

54 … connection part

61 … connection structure

62 … first connection object part

63. 64 … second connection object part

65. 66 … connection part

67 … other Metal-containing particles

68. 69 … heat sink

Detailed Description

The details of the present invention will be described below.

(Metal-containing particles)

The metal-containing particle of the present invention includes a base particle and a metal portion. The metal portion is disposed on the surface of the base particle. In the metal-containing particle of the present invention, the metal portion has a plurality of protrusions on an outer surface thereof. In the metal-containing particle of the present invention, the tip of the protrusion of the metal part can be melted at 400 ℃ or lower.

In the present invention, the above-described technical features are provided, and therefore, the distal ends of the protrusions of the metal part can be melted at a relatively low temperature. Therefore, the tips of the protrusions of the metal part in the metal-containing particles can be melted at a relatively low temperature, and after the melting, the metal part can be solidified to be joined to other particles or other members. In addition, a plurality of metal-containing particles may be fusion-bonded. Further, the metal-containing particles can be fusion-bonded to the member to be connected. Further, the metal-containing particles can be fusion bonded to the electrode.

It is known that when the particle diameter of the metal particles is reduced to a size of 100nm or less and the number of constituent atoms is reduced, the ratio of the surface area to the particle volume is rapidly increased, and the melting point or sintering temperature is greatly reduced as compared with the bulk state. The inventors of the present invention found that: by reducing the diameter of the tip of the protrusion of the metal portion, the melting temperature of the tip of the protrusion of the metal portion can be reduced, as in the case of using nano-sized metal particles.

In order to lower the melting temperature of the tip of the protrusion of the metal part, the protrusion may be formed in a sharp needle shape. In order to lower the melting temperature of the tip of the protrusion of the metal part, a plurality of small protrusions may be formed on the outer surface of the metal part. In order to lower the melting temperature of the tip of the protrusion of the metal part, in the metal-containing particle of the present invention, it is preferable that the metal part has a plurality of convex parts (first protrusions) on the outer surface, and the metal part has the protrusion (second protrusion) on the outer surface of the convex parts. The convex portion is preferably larger than the projection. The connection reliability is further improved by the presence of the convex portion, which is larger than the projection, and which is different from the projection. The convex portion and the projection may be integrated, or the projection may be attached to the convex portion. The protrusions may be formed of particles. In the present specification, a projection portion formed on the outer surface of the projection is referred to as a convex portion, unlike the projection described above. The tip of the projection may not be melted at 400 ℃ or lower.

Thus, the melting temperature can be lowered by reducing the diameter of the tip of the protrusion. In addition, the material of the metal portion may be selected in order to lower the melting temperature. In order to control the melting temperature of the tip of the protrusion of the metal part to 400 ℃ or lower, the shape of the protrusion and the material of the metal part are preferably selected.

The melting temperature of the tip of the protrusion of the metal part was evaluated as follows.

The melting temperature of the tip of the protrusion of the metal part can be measured using a differential scanning calorimeter ("DSC-6300" manufactured by Yamato scientific corporation). The measurement was carried out using 15g of metal-containing particles under measurement conditions of a temperature range of 30 ℃ to 500 ℃, a temperature rise rate of 5 ℃/min, and a nitrogen purge amount of 5 ml/min.

Next, it was confirmed that the tip of the protrusion of the metal part was melted at the melting temperature obtained in the above measurement. 1g of the metal-containing particles were put into a container and put into an electric furnace. The same temperature as the melting temperature obtained in the above measurement was set in an electric furnace, and the mixture was heated for 10 minutes in a nitrogen atmosphere. Thereafter, the heated metal-containing particles were taken out from the electric furnace, and the molten state (or the solidified state after the melting) of the tips of the protrusions was confirmed using a scanning electron microscope.

The shape of the protrusion is preferably a sharp needle shape from the viewpoint of effectively lowering the melting temperature of the tip of the protrusion and effectively improving the connection reliability. In the metal-containing particle, the shape of the projection on the outer surface of the metal part is different from the conventional shape, and a new effect is exhibited by the fact that the projection is in the shape of a sharp needle.

The metal-containing particles of the present invention can be used for joining two members to be joined together because the tips of the projections of the metal part can be fusion-joined at a relatively low temperature. By fusion-bonding the tips of the projections of the metal part in the metal-containing particles between the two members to be connected, a connection part exhibiting strong connection can be formed, and connection reliability can be improved.

In addition, the metal-containing particles of the present invention can be used for conductive connection. The metal-containing particles of the present invention can be used as a gap control material (spacer).

The average (a) of the apex angles of the plurality of protrusions is preferably 10 ° or more, more preferably 20 ° or more, preferably 60 ° or less, and more preferably 45 ° or less. When the average (a) of the apex angles is equal to or greater than the lower limit, the protrusions are less likely to bend excessively. When the average (a) of the apex angles is not more than the upper limit, the melting temperature becomes further low. The bent protrusion may increase the connection resistance between the electrodes during the conductive connection.

The average (a) of the top angles of the protrusions is obtained by averaging the top angles of the protrusions contained in 1 metal-containing particle.

The average height (b) of the plurality of protrusions is preferably 3nm or more, more preferably 5nm or more, further preferably 50nm or more, preferably 5000nm or less, more preferably 1000nm or less, and further preferably 800nm or less. When the average height (b) of the protrusions is not less than the lower limit, the melting temperature is further lowered. When the average height (b) of the protrusions is equal to or less than the upper limit, the protrusions are less likely to be excessively bent.

The average height (b) of the protrusions is an average of the heights of the protrusions contained in 1 metal-containing particle. When the metal part does not have the convex part but has the protrusion, the height of the protrusion indicates a distance from a virtual line (a broken line L2 shown in fig. 1) of the metal part when no protrusion is assumed (on the outer surface of the spherical metal-containing particle when no protrusion is assumed) to the tip of the protrusion on a line (a broken line L1 shown in fig. 1) connecting the center of the metal-containing particle and the tip of the protrusion. That is, fig. 1 shows the distance from the intersection of the broken line L1 and the broken line L2 to the tip of the protrusion. In the case where the metal portion has the projection and the projection, that is, the metal portion has the projection on the projection, the height of the projection indicates a distance from a virtual line of the metal portion (projection) when it is assumed that there is no projection to a tip of the projection. The protrusion may be an aggregate of a plurality of particles. For example, the protrusions may be formed by connecting a plurality of particles constituting the protrusions. In this case, the height of the protrusions is the height of the protrusions when the aggregate or connected particles of the plurality of particles are observed as a whole. In fig. 3, the height of the protrusions 1Ba and 3Ba indicates the distance from the virtual line of the metal portion to the tip of the protrusion when no protrusion is assumed.

The average diameter (c) of the base portions of the plurality of protrusions is preferably 3nm or more, more preferably 5nm or more, further preferably 50nm or more, preferably 1000nm or less, and more preferably 800nm or less. When the average diameter (c) is not less than the lower limit, the protrusions are less likely to be excessively bent. When the average diameter (c) is not more than the upper limit, the connection reliability is further improved.

The average diameter (c) of the base of the protrusion is an average value of the diameters of the bases of the protrusions contained in 1 metal-containing particle. The diameter of the base is the maximum diameter of each base of the protrusion. In the case where the metal part has the projection and the projection, that is, in the case where the metal part has the projection on the projection, an end of a virtual line portion of the metal part on a line connecting the center of the metal-containing particle and the tip of the projection, which is assumed to be free of the projection, is a base of the projection, and a distance between the ends of the virtual line portion (a distance connecting the ends with a straight line) is a diameter of the base.

The ratio of the average height (b) of the plurality of projections to the average diameter (c) of the base of the plurality of projections (average height (b)/average diameter (c)) is preferably 0.5 or more, more preferably 1.5 or more, preferably 10 or less, more preferably 5 or less. When the ratio (average height (b)/average diameter (c)) is equal to or higher than the lower limit, the connection reliability is further improved. When the ratio (average height (b)/average diameter (c)) is equal to or less than the upper limit, the protrusions are less likely to bend excessively.

The ratio (average diameter (d)/average diameter (c)) of the average diameter (d) at the center of the height of the plurality of projections to the average diameter (c) at the base of the plurality of projections is preferably 1/5 or more, more preferably 1/4 or more, further preferably 1/3 or more, preferably 4/5 or less, more preferably 3/4 or less, and further preferably 2/3 or less. When the ratio (average diameter (d)/average diameter (c)) is equal to or greater than the lower limit, the protrusions are less likely to bend excessively. When the ratio (average diameter (d)/average diameter (c)) is equal to or less than the upper limit, the connection reliability is further improved.

The average diameter (d) at the center of the height of the protrusions is the average of the diameters at the center of the height of the protrusions contained in 1 metal-containing particle. The diameter at the center position of the height of the protrusion is the maximum diameter of each center position of the height of the protrusion.

The shape of the plurality of protrusions is preferably a shape of a part of a needle or a sphere from the viewpoint of suppressing excessive bending of the protrusions, further improving the fusion bondability by the protrusions, and effectively improving the connection reliability. The shape of the needle is preferably a pyramid shape, a cone shape, or a paraboloid of revolution, more preferably a cone shape or a paraboloid of revolution, and still more preferably a cone shape. The shape of the projection may be a pyramid shape, a cone shape, or a rotational paraboloid shape. In the present invention, the paraboloid of revolution is included in the sharp needle shape. The rotating parabolic protrusion tapers from the base to the tip.

The protrusions on the outer surface of the metal part of 1 metal-containing particle are preferably 3 or more, and more preferably 5 or more. The upper limit of the number of the above-mentioned protrusions is not particularly limited. The upper limit of the number of protrusions may be appropriately selected in consideration of the particle diameter of the metal-containing particles and the like. The protrusions included in the metal-containing particles may not be in the form of sharp needles, and it is not necessary that all of the protrusions included in the metal-containing particles are in the form of sharp needles.

The ratio of the number of needle-like projections tapered at the tip to the number of projections contained in 1 metal-containing particle is preferably 30% or more, more preferably 50% or more, further preferably 60% or more, particularly preferably 70% or more, and most preferably 80% or more. The effect of the needle-like protrusions is more effectively obtained as the ratio of the number of needle-like protrusions is larger.

The ratio (x) of the surface area of the portion where the protrusion is present in 100% of the entire surface area of the outer surface of the metal portion is preferably 10% or more, more preferably 20% or more, further preferably 30% or more, preferably 90% or less, more preferably 80% or less, and further preferably 70% or less. The more the proportion of the surface area of the portion where the projections exist, the more effectively the effect by the projections is obtained.

From the viewpoint of effectively improving the connection reliability, the proportion of the surface area of the portion where the needle-like projections are present in 100% of the entire surface area of the outer surface of the metal part is preferably 10% or more, more preferably 20% or more, further preferably 30% or more, preferably 90% or less, more preferably 80% or less, further preferably 70% or less. The effect of the projections is more effectively obtained as the ratio of the surface area of the portion where the needle-like projections are present is larger.

The average (a) of the apex angles of the plurality of projections is preferably 10 ° or more, more preferably 20 ° or more, preferably 60 ° or less, and more preferably 45 ° or less. When the average (a) of the apex angles is equal to or greater than the lower limit, the convex portions are less likely to be excessively bent. When the average (a) of the apex angles is not more than the upper limit, the melting temperature becomes further low. The bent convex portion may increase the connection resistance between the electrodes during the conductive connection.

The average (a) of the apex angles of the convex portions is obtained by averaging the apex angles of the convex portions contained in 1 metal-containing particle.

The average height (B) of the plurality of projections is preferably 5nm or more, more preferably 50nm or more, preferably 5000nm or less, more preferably 1000nm or less, and further preferably 800nm or less. When the average height (B) of the projections is not less than the lower limit, the melting temperature is further lowered. When the average height (B) of the convex portions is equal to or less than the upper limit, the convex portions are less likely to be excessively bent.

The average height (B) of the projections is an average of the heights of the projections contained in 1 metal-containing particle. The height of the convex portion indicates a distance from a virtual line (a broken line L2 shown in fig. 8) of the metal portion when no convex portion is assumed (on the outer surface of the spherical metal-containing particle when no convex portion is assumed) to the tip of the convex portion on a line (a broken line L1 shown in fig. 8) connecting the center of the metal-containing particle and the tip of the convex portion. That is, fig. 8 shows the distance from the intersection of the broken line L1 and the broken line L2 to the tip of the projection.

The average diameter (C) of the base portions of the plurality of projections is preferably 3nm or more, more preferably 5nm or more, further preferably 50nm or more, preferably 5000nm or less, more preferably 1000nm or less, and further preferably 800nm or less. When the average diameter (C) is equal to or larger than the lower limit, the convex portion is less likely to be excessively bent. When the average diameter (C) is not more than the upper limit, the connection reliability is further improved.

The average diameter (C) of the base of the convex portion is the average value of the diameters of the base of the convex portion contained in 1 metal-containing particle. The diameter of the base portion is the maximum diameter of each base portion in the convex portion. The end of a virtual line portion (broken line L2 shown in fig. 8) of the metal part in the case where no projection is present on the line (broken line L1 shown in fig. 8) connecting the center of the metal-containing particle and the tip of the projection is the base of the projection, and the distance between the ends of the virtual line portion (the distance connecting the ends by a straight line) is the diameter of the base.

The ratio (average diameter (D)/average diameter (C)) of the average diameter (D) at the center position of the height of the plurality of projections to the average diameter (C) at the base of the plurality of projections is preferably 1/5 or more, more preferably 1/4 or more, further preferably 1/3 or more, preferably 4/5 or less, more preferably 3/4 or less, and further preferably 2/3 or less. When the ratio (average diameter (D)/average diameter (C)) is equal to or greater than the lower limit, the convex portion is less likely to be excessively bent. When the ratio (average diameter (D)/average diameter (C)) is equal to or less than the upper limit, the connection reliability is further improved.

The average diameter (D) at the center of the height of the convex portion is the average of the diameters at the center of the height of the convex portion contained in 1 metal-containing particle. The diameter at the center position of the height of the convex portion is the maximum diameter of each center position of the height of the convex portion.

The shape of the plurality of projections is preferably a shape of a needle or a part of a sphere from the viewpoints of suppressing excessive bending of the projections, further improving the fusion bondability by the projections, and effectively improving the connection reliability. The shape of the needle is preferably a pyramid shape, a cone shape, or a paraboloid of revolution, more preferably a cone shape or a paraboloid of revolution, and still more preferably a cone shape. The shape of the convex part may be a pyramid shape, a cone shape, or a rotational paraboloid shape. In the present invention, the rotational paraboloid shape is also included in the sharp needle shape. The convex portion of the paraboloid of revolution is tapered from the base to the tip.

The number of the convex portions on the outer surface of the metal portion of 1 metal-containing particle is preferably 3 or more, and more preferably 5 or more. The upper limit of the number of the convex portions is not particularly limited. The upper limit of the number of the convex portions may be appropriately selected in consideration of the particle diameter of the metal-containing particles. The convex portions included in the metal-containing particles may not be needle-shaped with tapered ends, and it is not necessary that all the convex portions included in the metal-containing particles are needle-shaped with tapered ends.

The ratio of the number of needle-like projections having a tapered tip to the number of projections contained in 1 metal-containing particle is preferably 30% or more, more preferably 50% or more, further preferably 60% or more, particularly preferably 70% or more, and most preferably 80% or more. The effect of the needle-like projections is more effectively obtained as the ratio of the number of needle-like projections is larger.

The ratio (X) of the surface area of the portion where the convex portion is present in 100% of the entire surface area of the outer surface of the metal portion is preferably 10% or more, more preferably 20% or more, further preferably 30% or more, preferably 90% or less, more preferably 80% or less, and further preferably 70% or less. The effect of the projection on the convex portion is more effectively obtained as the ratio of the surface area of the portion where the convex portion exists is larger.

From the viewpoint of effectively improving the connection reliability, the proportion of the surface area of the portion where the needle-like convex portion exists in 100% of the entire surface area of the outer surface of the metal portion is preferably 10% or more, more preferably 20% or more, further preferably 30% or more, preferably 90% or less, more preferably 80% or less, further preferably 70% or less. The effect of the projection on the convex portion is more effectively obtained as the ratio of the surface area of the portion where the needle-like convex portion exists is larger.

The ratio of the average height (B) of the plurality of projections to the average height (B) of the plurality of projections (average height (B)/average height (B)) is preferably 5 or more, more preferably 10 or more, preferably 1000 or less, and more preferably 800 or less. When the ratio (average height (B)/average height (B)) is equal to or higher than the lower limit, the connection reliability is further improved. When the ratio (average height (B)/average height (B)) is equal to or less than the upper limit, the convex portion is less likely to be bent excessively.

The metal portion having a plurality of the protrusions is preferably formed by crystal orientation of a metal or an alloy. In the embodiments described later, the metal portion is formed by crystal orientation of a metal or an alloy.

From the viewpoint of effectively improving the connection reliability, the compression elastic modulus (10% K value) when the metal-containing particles are compressed by 10% is preferably 100N/mm²Above, more preferably 1000N/mm²Above, preferably 25000N/mm²The concentration is preferably 10000N/mm or less²Hereinafter, more preferably 8000N/mm²The following.

The compressive modulus of elasticity (10% K value) of the metal-containing particles can be measured as follows.

The metal-containing particles were compressed at 25 ℃ and a compression rate of 0.3 mN/sec and a maximum test load of 20mN on a smooth presser end face of a cylinder (made of diamond with a diameter of 100 μm) using a micro compression tester. The load value (N) and the compression displacement (mm) were measured. From the obtained measurement values, the compression modulus can be obtained by the following equation. As the micro compression tester, for example, "FISCERSCOPE H-100" manufactured by FISCER K.K.K. can be used.

10% K value (N/mm)²)＝(3/2^1/2)·F·S^-3/2·R^-1/2

F: load value (N) when metal-containing particles are compressed and deformed by 10%

S: compression deflection (mm) when the metal-containing particles are compressed and deformed by 10%

R: radius (mm) of the Metal-containing particles

The ratio of the (111) plane in the X-ray diffraction of the protrusion is preferably 50% or more.

Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.

Fig. 1 is a cross-sectional view schematically showing a metal-containing particle according to a first embodiment of the present invention.

As shown in fig. 1, the metal-containing particle 1 includes a base particle 2 and a metal portion 3.

The metal portion 3 is disposed on the surface of the base particle 2. The metal-containing particles 1 are coated particles in which the surfaces of the base particles 2 are coated with the metal portions 3. The metal part 3 is a continuous film.

The metal-containing particle 1 has a plurality of protrusions 1a on the outer surface of the metal part 3. The metal part 3 has a plurality of protrusions 3a on the outer surface. The plurality of projections 1a and 3a are needle-shaped with tapered tips, and in the present embodiment, are conical. In the present embodiment, the tips of the protrusions 1a and 3a can be melted at 400 ℃ or lower. The metal part 3 has a first portion and a second portion thicker than the first portion. The portions other than the plurality of projections 1a and 3a are the first portions of the metal portion 3. The plurality of projections 1a and 3a are the second portions of the metal portion 3 having a large thickness.

Fig. 2 is a cross-sectional view schematically showing a metal-containing particle according to a second embodiment of the present invention.

As shown in fig. 2, the metal-containing particle 1A includes a base particle 2 and a metal portion 3A.

The metal portion 3A is disposed on the surface of the base particle 2. The metal-containing particles 1A have a plurality of protrusions 1Aa on the outer surface of the metal portion 3A. The metal portion 3A has a plurality of protrusions 3Aa on the outer surface. The plurality of projections 1Aa and 3Aa are needle-like with tapered tips, and in the present embodiment, are in the shape of a paraboloid of revolution. In the present embodiment, the tips of the projections 1Aa and 3Aa can be melted at 400 ℃ or lower.

As in the metal-containing particles 1 and the metal-containing particles 1A, the shape of the plurality of projections of the metal portion is preferably a needle shape whose tip is tapered, and may be a conical shape or a rotational parabolic shape.

Fig. 3 is a cross-sectional view schematically showing a metal-containing particle according to a third embodiment of the present invention.

As shown in fig. 3, the metal-containing particle 1B includes a base particle 2 and a metal portion 3B.

The metal portion 3B is disposed on the surface of the base particle 2. The metal-containing particles 1B have a plurality of protrusions 1Ba on the outer surface of the metal portion 3B. The metal portion 3B has a plurality of protrusions 3Ba on the outer surface. The plurality of protrusions 1Ba and 3Ba have a shape of a part of a sphere. The metal portion 3B has metal particles 3BX embedded so as to be partially exposed on the outer surface. The exposed portions of the metal particles 3BX constitute the protrusions 1Ba and 3 Ba. In the present embodiment, the tips of the protrusions 1Ba and 3Ba can be melted at 400 ℃.

Since the protrusions are reduced in size as in the metal-containing particles 1B, the protrusions may not have a needle shape with a tapered tip, but may have a shape of a part of a sphere, for example.

Fig. 4 is a cross-sectional view schematically showing metal-containing particles according to a fourth embodiment of the present invention.

As shown in fig. 4, the metal-containing particle 1C includes a base particle 2 and a metal portion 3C.

In the metal-containing particle 1 and the metal-containing particle 1C, only the metal portion is different. That is, in the metal-containing particle 1, the metal part 3 having a 1-layer structure is formed, whereas in the metal-containing particle 1C, the metal part 3C having a 2-layer structure is formed.

Metal portion 3C has first metal portion 3CA and second metal portion 3 CB. The first metal portion 3CA and the second metal portion 3CB are disposed on the surface of the base particle 2. The first metal portion 3CA is disposed between the base particle 2 and the second metal portion 3 CB. Therefore, the first metal portion 3CA is disposed on the surface of the base particle 2, and the second metal portion 3CB is disposed on the outer surface of the first metal portion 3 CA. The first metal portion 3CA has a spherical outer shape. The metal-containing particle 1C has a plurality of protrusions 1Ca on the outer surface of the metal portion 3C. The metal part 3C has a plurality of protrusions 3Ca on the outer surface. The second metal part 3CB has a plurality of protrusions on the outer surface. The plurality of projections 1Ca and 3Ca are needle-shaped with tapered tips, and in the present embodiment, are conical. In the present embodiment, the tips of the protrusions 1Ca and 3Ca can be melted at 400 ℃. The inner first metal part may have a plurality of protrusions on an outer surface.

Fig. 5 is a cross-sectional view schematically showing metal-containing particles according to a fifth embodiment of the present invention.

As shown in fig. 5, the metal-containing particle 1D includes a base particle 2 and a metal portion 3D.

The metal portion 3D is disposed on the surface of the base particle 2. The metal-containing particle 1D has a plurality of protrusions 1Da on the outer surface of the metal portion 3D. The metal-containing particle 1D has a plurality of convex portions (first protrusions) 3Da on the outer surface of the metal portion 3D. The metal portion 3D has a plurality of convex portions (first protrusions) 3Da on the outer surface. The metal portion 3D has a protrusion 3Db (second protrusion) smaller than the convex portion (first protrusion) 3Da on the outer surface of the convex portion (first protrusion) 3 Da. The convex portion (first protrusion) 3Da and the protrusion 3Db (second protrusion) are integrated to be connected. In the present embodiment, the diameter of the tip of the protrusion 3Db (second protrusion) is small, and the tip of the protrusion 3Db (second protrusion) can be melted at 400 ℃.

Fig. 6 is a cross-sectional view schematically showing metal-containing particles according to a sixth embodiment of the present invention.

As shown in fig. 6, the metal-containing particle 1E includes a base particle 2, a metal portion 3E, and a core material 4E.

The metal portion 3E is disposed on the surface of the base particle 2. The metal-containing particle 1E has a plurality of protrusions 1Ea on the outer surface of the metal portion 3E. The metal-containing particle 1E has a plurality of convex portions (first protrusions) 3Ea on the outer surface of the metal portion 3E. The metal portion 3E has a plurality of convex portions (first protrusions) 3Ea on the outer surface. The metal portion 3E has a protrusion 3Eb (second protrusion) smaller than the convex portion (first protrusion) 3Ea on the outer surface of the convex portion (first protrusion) 3 Ea. The convex portion (first protrusion) 3Ea and the protrusion 3Eb (second protrusion) are integrated to realize connection. In the present embodiment, the diameter of the tip of the protrusion 3Eb (second protrusion) is small, and the tip of the protrusion 3Eb (second protrusion) can be melted at 400 ℃.

The plurality of core materials 4E are disposed on the outer surface of the base particle 2. The plurality of core materials 4E are disposed inside the metal portion 3E. The plurality of core materials 4E are embedded inside the metal portion 3E. The core material 4E is disposed inside the convex portion 3 Ea. The metal portion 3E covers the plurality of core materials 4E. Due to the plurality of core materials 4E, the outer surface of the metal portion 3E is raised to form the convex portion 3 Ea.

For example, the metal-containing particle 1E may include a plurality of core materials that swell the outer surface of the metal portion.

Fig. 7 is a cross-sectional view schematically showing metal-containing particles according to a seventh embodiment of the present invention.

As shown in fig. 7, the metal-containing particles 1F include base particles 2 and metal portions 3F.

The metal portion 3F is disposed on the surface of the base particle 2. The metal-containing particle 1F has a plurality of protrusions 1Fa on the outer surface of the metal portion 3F. The metal part 3F has a projection 3Fb (second projection) smaller than the convex part (first projection) 3Fa on the outer surface of the convex part (first projection) 3 Fa. The convex portion (first protrusion) 3Fa and the protrusion 3Fb (second protrusion) are not integrated. In the present embodiment, the diameter of the tip of the projection 3Fb (second projection) is small, and the tip of the projection 3Fb (second projection) can be melted at 400 ℃.

Fig. 8 is a cross-sectional view schematically showing metal-containing particles according to an eighth embodiment of the present invention.

As shown in fig. 8, the metal-containing particles 1G include base particles 2 and metal portions 3G.

The metal portion 3G includes a first metal portion 3GA and a second metal portion 3 GB. The first metal portion 3GA and the second metal portion 3GB are disposed on the surface of the base particle 2. The first metal portion 3GA is disposed between the base particle 2 and the second metal portion 3 GB. Therefore, the first metal portion 3GA is disposed on the surface of the base particle 2, and the second metal portion 3GB is disposed on the outer surface of the first metal portion 3 GA.

The metal portion 3G is disposed on the surface of the base particle 2. The metal-containing particle 1G has a plurality of projections 1Ga on the outer surface of the metal portion 3G. The metal-containing particle 1G has a plurality of convex portions (first protrusions) 3Ga on the outer surface of the metal portion 3G. The metal portion 3G has projections 3Gb (second projections) smaller than the convex portion (first projections) 3Ga on the outer surface of the convex portion (first projections) 3 Ga. An interface exists between the convex portion (first protrusion) 3Ga and the protrusion 3Gb (second protrusion). In the present embodiment, the diameter of the tip of the protrusion 3Gb (second protrusion) is small, and the tip of the protrusion 3Gb (second protrusion) can be melted at 400 ℃.

In addition, fig. 11 to 14 actually show images of the metal-containing particles produced. The metal-containing particles shown in FIGS. 11 to 14 have a plurality of protrusions on the outer surface of the metal part, and the tips of the plurality of protrusions can be melted at 400 ℃ or lower. In the metal-containing particle shown in fig. 14, the metal part has a plurality of convex portions on the outer surface, and the convex portions have projections smaller than the convex portions on the outer surface.

Fig. 15 to 18 show images of particles solidified after the projections of the metal portion of the produced metal-containing particles are melted. FIG. 18 shows a particle obtained by melting and then solidifying the distal ends of the protrusions of the metal part of the metal-containing particle shown in FIG. 14.

The metal-containing particles are described in more detail below. In the following description, "(meth) acrylic acid" means one or both of "acrylic acid" and "methacrylic acid", and "(meth) acrylate" means one or both of "acrylate" and "methacrylate".

[ base material particles ]

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

The base material 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 material particles, metal-containing particles preferable for the use of connecting two members to be connected can be obtained.

When the base material particles are resin particles or organic-inorganic hybrid particles, the metal-containing particles are easily deformed, and the flexibility of the metal-containing particles is improved. Therefore, after the connection, the impact absorbability is increased.

As the resin for forming the resin particles, various organic substances are preferably 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 polymethacrylate; polyalkylene terephthalate, polycarbonate, polyamide, phenol-formaldehyde resin, melamine-formaldehyde resin, benzoguanamine-formaldehyde resin, urea-formaldehyde resin, phenol resin, melamine resin, benzoguanamine resin, urea resin, epoxy resin, unsaturated polyester resin, saturated polyester resin, polysulfone, polyphenylene oxide, polyacetal, polyimide, polyamideimide, polyether ether ketone, polyether sulfone, and a polymer obtained by polymerizing 1 or 2 or more kinds of various polymerizable monomers having an ethylenically unsaturated group. Since resin particles having arbitrary physical properties suitable for the purpose of connecting two members to be connected at the time of compression can be designed and synthesized, and the hardness of the base material particles can be easily controlled within an appropriate range, the resin for forming the resin particles is preferably a polymer obtained by polymerizing 1 or 2 or more kinds of polymerizable monomers having a plurality of ethylenically unsaturated groups.

When the resin particles are obtained by polymerizing a polymerizable monomer having an ethylenically unsaturated group, examples of the polymerizable monomer having an ethylenically unsaturated group include a non-crosslinkable monomer and a crosslinkable monomer.

Examples of the non-crosslinkable monomer include: styrene monomers such as styrene and alpha-methylstyrene; carboxyl group-containing monomers such as (meth) acrylic acid, maleic acid, and maleic anhydride; alkyl (meth) acrylate compounds such as methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, cetyl (meth) acrylate, stearyl (meth) acrylate, cyclohexyl (meth) acrylate, and isobornyl (meth) acrylate; oxygen atom-containing (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; vinyl ester acid compounds such as vinyl acetate, vinyl butyrate, vinyl laurate and vinyl stearate; unsaturated hydrocarbons such as ethylene, propylene, isoprene, and butadiene; and halogen-containing monomers such as trifluoromethyl (meth) acrylate, pentafluoroethyl (meth) acrylate, vinyl chloride, vinyl fluoride, and chlorostyrene.

Examples of the crosslinkable monomer include: polyfunctional (meth) acrylate compounds such as tetramethylolmethane tetra (meth) acrylate, tetramethylolmethane tri (meth) acrylate, tetramethylolmethane di (meth) acrylate, trimethylolpropane tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, dipentaerythritol penta (meth) acrylate, glycerol tri (meth) acrylate, glycerol di (meth) acrylate, (poly) ethylene glycol di (meth) acrylate, (poly) propylene glycol di (meth) acrylate, (poly) tetramethylene glycol di (meth) acrylate, and 1, 4-butanediol di (meth) acrylate; silane-containing monomers such as triallyl (iso) cyanurate, triallyl trimellitate, divinylbenzene, diallyl phthalate, diallyl acrylamide, diallyl ether, γ - (meth) acryloxypropyl trimethoxysilane, trimethoxysilylstyrene, and vinyltrimethoxysilane.

The resin particles can be obtained by polymerizing the polymerizable monomer having the ethylenically unsaturated group by a known method. Examples of the method include: a method of performing suspension polymerization in the presence of a radical polymerization initiator, a method of swelling a monomer together with a radical polymerization initiator and polymerizing a sample non-crosslinked seed particle, and the like.

When the base particles are inorganic particles or organic-inorganic hybrid particles other than metal particles, examples of the inorganic substance used to form the base particles include silica, alumina, barium titanate, zirconia, carbon black, and the like. The inorganic substance is preferably a nonmetal. The particles made of the silica are not particularly limited, and include, for example, particles obtained by hydrolyzing a silicon compound having 2 or more hydrolyzable alkoxysilyl groups to form crosslinked polymer particles, and then, if necessary, firing the crosslinked polymer particles. 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 a cartridge core. The shell is preferably an inorganic shell. The base material particle is preferably an organic-inorganic hybrid particle having an organic core and an inorganic shell disposed on a surface of the organic core, from the viewpoint of effectively improving connection reliability.

Examples of the material for forming the inorganic shell include inorganic materials for forming the base particles. The material used to form the inorganic shell is preferably silica. The inorganic shell is preferably formed by forming a metal alkoxide as a shell on the surface of the core by a solvent gel method, and then firing the shell. The metal alkoxide is preferably a silanolate. The inorganic shell is preferably formed of silanolate.

The particle diameter of the core is preferably 0.5 μm or more, more preferably 1 μm or more, preferably 500 μm or less, more preferably 100 μm or less, further preferably 50 μm or less, particularly preferably 20 μm or less, and most preferably 10 μm or less. When the particle diameter of the core is not less than the lower limit and not more than the upper limit, the core can be preferably used for connecting two members to be connected. For example, when the particle diameter of the core is not less than the lower limit and not more than the upper limit, in the case where two members to be connected are connected by using the metal-containing particles, the contact area between the metal-containing particles and the members to be connected is sufficiently increased, and the aggregated metal-containing particles are not easily formed when the metal part is formed. Further, the distance between the two members to be connected via the metal-containing particles is not excessively large, and the metal portion is not easily peeled off from the surface of the base material particle.

The particle diameter of the core means a diameter when the core is spherical, and means a maximum diameter when the core is other than spherical. The particle size of the core means an average particle size obtained by measuring the core with an arbitrary particle size measuring apparatus. For example, a particle size distribution measuring instrument using the principle of laser light scattering, resistance value change, image analysis after imaging, and the like can be used.

The thickness of the shell is preferably 100nm or more, more preferably 200nm or more, preferably 5 μm or less, and more preferably 3 μm or less. When the thickness of the shell is not less than the lower limit and not more than the upper limit, the shell can be preferably used for connecting two members to be connected. The thickness of the shell is an average thickness of 1 base material particle. The thickness of the shell can be controlled by controlling the solvent gel method.

When the base particles are metal particles, examples of the metal used to form the metal particles include silver, copper, nickel, silicon, gold, titanium, and the like. However, the base material particles are preferably not metal particles.

The particle diameter of the base material particles is preferably 0.1 μm or more, more preferably 0.5 μm or more, still more preferably 1 μm or more, still more preferably 1.5 μm or more, particularly preferably 2 μm or more, preferably 1000 μm or less, more preferably 500 μm or less, still more preferably 400 μm or less, still more preferably 100 μm or less, still more preferably 50 μm or less, still more preferably 30 μm or less, particularly preferably 5 μm or less, and most preferably 3 μm or less. When the particle size of the base material particle is not less than the lower limit, the connection reliability is further improved. Further, when the metal portion is formed on the surface of the base material particle by electroless plating, the metal portion is less likely to aggregate, and aggregated metal-containing particles are less likely to be formed. When the average particle diameter of the base material particles is not more than the upper limit, the metal-containing particles are easily sufficiently compressed, and the connection reliability is further improved.

The particle diameter of the base material particle indicates a diameter when the base material particle is a regular sphere, and indicates a maximum diameter when the base material particle is not a regular sphere.

The base material particles are preferably particles containing a silicone resin (silicone particles) from the viewpoint of further suppressing the occurrence of cracks or peeling in the connection portion in a thermal cycle test for connection reliability, and further suppressing the occurrence of cracks at the time of stress loading. The material of the base material particles preferably contains a silicone resin.

The material of the polysiloxane particles is preferably a silane compound having a radical polymerizable group and a silane compound having a hydrophobic group having 5 or more carbon atoms, a silane compound having a radical polymerizable group and a hydrophobic group having 5 or more carbon atoms, or a silane compound having radical polymerizable groups at both ends. In the case of reacting these materials, a siloxane bond is formed. In general, a radical polymerizable group and a hydrophobic group having 5 or more carbon atoms remain in the resulting polysiloxane particles. By using such a material, silicone particles having a1 st order particle diameter of 0.1 μm or more and 500 μm or less can be easily obtained, and the chemical resistance of the silicone particles can be improved and the moisture permeability can be reduced.

In the silane compound having the radical polymerizable group, the radical polymerizable group is preferably directly bonded to a silicon atom. The silane compound having the radical polymerizable group may be used in 1 kind alone, or 2 or more kinds in combination.

The silane compound having the radical polymerizable group is preferably an alkoxysilane compound. Examples of the silane compound having the radical polymerizable group include: vinyltrimethoxysilane, vinyltriethoxysilane, dimethoxymethylvinylsilane, diethoxymethylvinylsilane, divinylmethoxyvinylsilane, divinylethoxyvinylsilane, divinyldimethoxysilane, divinyldiethoxysilane, and 1, 3-divinyltetramethyldisiloxane.

In the silane compound having the hydrophobic group having 5 or more carbon atoms, the hydrophobic group having 5 or more carbon atoms is preferably directly bonded to a silicon atom. The silane compound having a hydrophobic group having 5 or more carbon atoms may be used alone in 1 kind or in combination with 2 or more kinds.

The silane compound having a hydrophobic group having 5 or more carbon atoms is preferably an alkoxysilane compound. Examples of the silane compound having a hydrophobic group having 5 or more carbon atoms include: phenyltrimethoxysilane, dimethoxymethylphenylsilane, diethoxymethylphenylsilane, dimethylmethoxyphenylsilane, dimethylethoxyphenylsilane, hexaphenyldisiloxane, 1,3,3, 5-tetramethyl-1, 1,5, 5-tetravinyltrisiloxane, 1,3,5, 5-pentaphenyl-1, 3, 5-trimethyltrisiloxane, hexaphenylcyclotrisiloxane, phenyltris (trimethylsiloxy) silane, octaphenylcyclotetrasiloxane and the like.

In the above silane compound having a radically polymerizable group and a hydrophobic group having 5 or more carbon atoms, the radically polymerizable group is preferably directly bonded to a silicon atom, and the hydrophobic group having 5 or more carbon atoms is preferably directly bonded to a silicon atom. The silane compound having a radically polymerizable group and a hydrophobic group having 5 or more carbon atoms may be used in 1 kind alone or in combination of 2 or more.

Examples of the silane compound having a radically polymerizable group and a hydrophobic group having 5 or more carbon atoms include: phenylvinyldimethoxysilane, phenylvinyldiethoxysilane, phenylmethylvinylmethoxysilane, phenylmethylvinylethoxysilane, diphenylvinylmethoxysilane, diphenylvinylethoxysilane, phenyldivinylmethoxysilane, phenyldivinylethoxysilane, and 1,1,3, 3-tetraphenyl-1, 3-divinyldisiloxane.

In the case where the silane compound having the radical polymerizable group and the silane compound having the hydrophobic group having 5 or more carbon atoms are used for obtaining the polysiloxane particles, the silane compound having the radical polymerizable group and the silane compound having the hydrophobic group having 5 or more carbon atoms are preferably used in a weight ratio of 1:1 to 1:20, more preferably 1:5 to 1: 15.

The number of radical polymerizable groups and the number of hydrophobic groups having 5 or more carbon atoms in the entire silane compound used to obtain the polysiloxane particles are preferably 1:0.5 to 1:20, and more preferably 1:1 to 1: 15.

From the viewpoint of effectively improving chemical resistance, effectively reducing moisture permeability, and controlling the 10% K value within a suitable range, the polysiloxane particles preferably have a dimethylsiloxane skeleton in which 2 methyl groups are bonded to 1 silicon atom, and the material of the polysiloxane particles preferably contains a silane compound in which 2 methyl groups are bonded to 1 silicon atom.

From the viewpoints of effectively improving chemical resistance, effectively reducing moisture permeability, and controlling the 10% K value within an appropriate range, the polysiloxane particles preferably react with the silane compound using a radical polymerization initiator to form siloxane bonds. In general, it is difficult to obtain polysiloxane particles having a 1-order particle diameter of 0.1 to 500 μm, particularly 100 μm, using a radical polymerization initiator. On the other hand, even when a radical polymerization initiator is used, silicone particles having a 1-order particle diameter of 0.1 μm or more and 500 μm or less can be obtained by using the silane compound, and silicone particles having a 1-order particle diameter of 100 μm or less can be obtained.

In order to obtain the polysiloxane particles, a silane compound having a hydrogen atom bonded to a silicon atom may not be used. In this case, the silane compound may be polymerized using a radical polymerization initiator without using a metal catalyst. As a result, the metal catalyst can be eliminated from the silicone particles, the content of the metal catalyst in the silicone particles can be reduced, the chemical resistance can be further effectively improved, the moisture permeability can be effectively reduced, and the 10% K value can be controlled to be within an appropriate range.

Specific examples of the method for producing the polysiloxane particles include a method in which a silane compound is polymerized by suspension polymerization, dispersion polymerization, miniemulsion polymerization, or emulsion polymerization, to produce polysiloxane particles. The polymerization of the silane compound is carried out to obtain a polymer, and then the polymerization reaction of the silane compound as a polymer (such as a polymer) can be carried out by suspension polymerization, dispersion polymerization, miniemulsion polymerization, or emulsion polymerization, to produce polysiloxane particles. For example, a silane compound having a vinyl group to which a silicon atom is bonded at a terminal can be obtained by polymerizing a silane compound having a vinyl group. The silane compound having a phenyl group can be polymerized to obtain a polymer (such as a polymer) having a phenyl group bonded to a silicon atom in a side chain. The silane compound having a vinyl group and the silane compound having a phenyl group can be polymerized to obtain a polymer (oligomer or the like) having a vinyl group bonded to a silicon atom at the terminal and a phenyl group bonded to a silicon atom at the side chain.

The polysiloxane particles may have a plurality of particles on the outer surface. In this case, the silicone particles may include a silicone particle body and a plurality of particles disposed on the surface of the silicone particle body. As the plurality of particles. Examples thereof include polysiloxane particles and spherical silica. The presence of the plurality of particles suppresses the aggregation of the silicone particles.

[ Metal portion ]

The tip of the protrusion of the metal part can be melted at 400 ℃ or lower. From the viewpoint of suppressing the consumption of energy during heating by lowering the melting temperature and further suppressing thermal degradation of the members to be connected and the like, the tip of the protrusion of the metal part is preferably meltable at 350 ℃ or less, more preferably at 300 ℃ or less, still more preferably at 250 ℃ or less, and particularly preferably at 200 ℃ or less. The melting temperature of the tip of the protrusion may be controlled according to the type of metal of the tip of the protrusion and the shape of the tip of the protrusion. The melting point of the base of the projection, the central position of the height of the projection, the base of the projection, and the central position of the height of the projection may exceed 200 ℃, 250 ℃, 300 ℃, 350 ℃ or 400 ℃. The metal part, the convex part and the protrusion may have a portion exceeding 200 ℃, a portion exceeding 250 ℃, a portion exceeding 300 ℃, a portion exceeding 350 ℃, or a portion exceeding 400 ℃.

The material of the metal part is not particularly limited. The material of the metal portion preferably contains a metal. Examples of the metal include: gold, silver, palladium, rhodium, iridium, lithium, copper, platinum, zinc, iron, tin, lead, ruthenium, aluminum, cobalt, indium, nickel, chromium, titanium, antimony, bismuth, thallium, germanium, cadmium, silicon, alloys thereof, and the like. Further, examples of the metal include tin-doped indium oxide (ITO).

In the present invention, the material of the metal part is selected so that the tip of the protrusion of the metal part can be melted at 400 ℃ or lower.

The material of the protrusion preferably contains silver, copper, gold, palladium, tin, indium, or zinc from the viewpoint of effectively improving the connection reliability. The material of the protrusion may not contain tin.

The material of the metal part is preferably not solder. Since the material of the metal portion is not solder, the entire metal portion can be prevented from being excessively melted. The material of the metal portion may not contain tin.

From the viewpoint of effectively improving the connection reliability, the material of the metal portion preferably contains silver, copper, gold, palladium, tin, indium, zinc, nickel, cobalt, iron, tungsten, molybdenum, ruthenium, platinum, rhodium, iridium, phosphorus, or boron, more preferably contains silver, copper, gold, palladium, tin, indium, or zinc, and further preferably contains silver. These preferred materialsThe number of the compounds may be 1 alone or 2 or more in combination. The silver may be contained as a simple substance of silver or as silver oxide, from the viewpoint of effectively improving connection reliability. The silver oxide may be Ag₂O and AgO.

The content of silver in 100 wt% of the metal portion containing silver is preferably 0.1 wt% or more, more preferably 1 wt% or more, preferably 100 wt% or less, more preferably 90 wt% or less, and may be 80 wt% or less, or 60 wt% or less, or 40 wt% or less, or 20 wt% or less, or 10 wt% or less. When the silver content is not less than the lower limit and not more than the upper limit, the bonding strength is improved, and the connection reliability is further improved.

The copper may be contained in the form of a simple substance of copper or copper oxide.

The copper content in 100 wt% of the copper-containing metal portion is preferably 0.1 wt% or more, more preferably 1 wt% or more, preferably 100 wt% or less, more preferably 90 wt% or less, and may be 80 wt% or less, may be 60 wt% or less, may be 40 wt% or less, may be 20 wt% or less, and may be 10 wt% or less. When the copper content is not less than the lower limit and not more than the upper limit, the bonding strength is improved, and the connection reliability is further improved.

The metal part may be formed of 1 layer. The metal part may be formed of a plurality of layers.

The outer surface of the metal part may be subjected to rust prevention treatment. The metal-containing particles may have a rust-preventive film on the outer surface of the metal part. Examples of the rust-proofing treatment include a method in which a rust-proofing agent is disposed on the outer surface of the metal part; a method of alloying the outer surface of the metal part and improving corrosion resistance; and a method of coating the outer surface of the metal part with a highly corrosion-resistant metal film. Examples of the rust inhibitor include: nitrogen-containing heterocyclic compounds such as benzotriazole compounds and imidazole compounds; sulfur-containing compounds such as thiol compounds, imidazole compounds, and organic disulfide compounds; phosphorus-containing compounds such as organic phosphoric acid compounds.

[ Rust-proofing treatment ]

In order to suppress corrosion of the metal-containing particles and reduce the connection resistance between electrodes, it is preferable to subject the outer surface of the metal portion to an anti-rust treatment or a vulcanization resistance treatment.

Examples of the vulcanization inhibitor, rust inhibitor and discoloration inhibitor include: nitrogen-containing heterocyclic compounds such as benzotriazole compounds and imidazole compounds; sulfur-containing compounds such as thiol compounds, imidazole compounds and organic disulfide compounds; phosphorus-containing compounds such as organic phosphoric acid compounds.

From the viewpoint of further improving the conduction reliability, it is preferable that the outer surface of the metal part is subjected to an anti-rust treatment using a compound having an alkyl group having 6 to 22 carbon atoms. The surface of the metal part may be subjected to an anticorrosive treatment with a compound containing no phosphorus, or may be subjected to an anticorrosive treatment with a compound containing an alkyl group having 6 to 22 carbon atoms and containing no phosphorus. From the viewpoint of further improving the conduction reliability, it is preferable to perform rust prevention treatment on the outer surface of the metal part with an alkyl phosphate compound or an alkyl thiol. By the rust prevention treatment, a rust prevention film can be formed on the outer surface of the metal part.

The rust preventive film is preferably formed from a compound having an alkyl group having 6 to 22 carbon atoms (hereinafter, also referred to as compound A). The outer surface of the metal part is preferably surface-treated with the compound a. When the number of carbon atoms of the alkyl group is 6 or more, the entire metal portion is further less likely to generate rust. When the number of carbon atoms of the alkyl group is 22 or less, the conductivity of the metal-containing particles is improved. From the viewpoint of further improving the conductivity of the metal-containing particles, the number of carbon atoms of the alkyl group in the compound a is preferably 16 or less. The alkyl group may have a straight chain structure or a branched structure. The alkyl group preferably has a linear structure.

The compound A is not particularly limited as long as it has an alkyl group having 6 to 22 carbon atoms. The compound A is preferably a phosphate having an alkyl group having 6 to 22 carbon atoms or a salt thereof; a phosphite ester having an alkyl group having 6 to 22 carbon atoms or a salt thereof; an alkoxysilane having an alkyl group having 6 to 22 carbon atoms; an alkylthiol having an alkyl group having 6 to 22 carbon atoms; or a dialkyl disulfide having an alkyl group having 6 to 22 carbon atoms. That is, the compound A having an alkyl group having 6 to 22 carbon atoms is preferably a phosphate or a salt thereof, a phosphite or a salt thereof, an alkoxysilane, an alkylthiol, or a dialkyldisulfide. By using these preferable compounds a, rust is further less likely to occur on the metal portion. From the viewpoint of further reducing the generation of rust, the compound a is preferably the phosphate or a salt thereof, the phosphite or a salt thereof, or an alkylthiol, and more preferably the phosphate or a salt thereof, or the phosphite or a salt thereof. The compound A may be used alone in 1 kind, or in combination of 2 or more kinds.

The compound a preferably has a reactive functional group that can react with the outer surface of the metal part. When the metal-containing particles include an insulating material disposed on the outer surface of the metal part, the compound a preferably has a reactive functional group capable of reacting with the insulating material. The rust preventive film is preferably chemically bonded to the metal part. The rust preventive film is preferably chemically bonded to the insulating material. The rust-preventive film is more preferably chemically bonded to both the metal part and the insulating material. The peeling of the rust preventive film is less likely to occur due to the presence of the reactive functional group and the chemical bonding, and as a result, rust is more less likely to occur on the metal portion, and the insulating material is further less likely to be unintentionally separated from the surface of the metal-containing particles.

Examples of the phosphate ester having an alkyl group having 6 to 22 carbon atoms or a salt thereof include: hexyl phosphate, heptyl phosphate, monooctyl phosphate, monononyl phosphate, monodecanyl phosphate, monoundecyl phosphate, monododecyl phosphate, monotridecyl phosphate, monotetradecyl phosphate, monopentadecyl phosphate, monohexyl phosphate monosodium salt, monooheptyl phosphate monosodium salt, monooctyl phosphate monosodium salt, monononyl phosphate monosodium salt, monodecanyl phosphate monosodium salt, monoundecyl phosphate monosodium salt, monododecyl phosphate monosodium salt, monotridecyl phosphate monosodium salt, monotetradecyl phosphate monosodium salt, and monopentadecyl phosphate monosodium salt. The potassium salts of the above-mentioned phosphoric esters can be used.

The phosphite ester having an alkyl group having 6 to 22 carbon atoms or a salt thereof includes, for example: hexyl phosphite, heptyl phosphite, monooctyl phosphite, monononyl phosphite, monodecanyl phosphite, monoundecyl phosphite, monododecyl phosphite, monotridecyl phosphite, monotetradecyl phosphite, monopentadecyl phosphite, monohexyl phosphite monosodium salt, monooheptyl phosphite monosodium salt, monooctyl phosphite monosodium salt, monononyl phosphite monosodium salt, monodecanyl phosphite monosodium salt, monoundecyl phosphite monosodium salt, monododecyl phosphite monosodium salt, monotridecyl phosphite monosodium salt, monotetradecyl phosphite monosodium salt, and monopentadecyl phosphite monosodium salt. The potassium salts of the above phosphites may be used.

Examples of the alkoxysilane having an alkyl group having 6 to 22 carbon atoms include: hexyltrimethoxysilane, hexyltriethoxysilane, heptyltrimethoxysilane, heptyltriethoxysilane, octyltrimethoxysilane, octyltriethoxysilane, nonyltrimethoxysilane, nonyltriethoxysilane, decyltrimethoxysilane, decyltriethoxysilane, undecyltrimethoxysilane, undecyltriethoxysilane, dodecyltrimethoxysilane, dodecyltriethoxysilane, tridecyltrimethoxysilane, tridecyltriethoxysilane, tetradecyltrimethoxysilane, tetradecyltriethoxysilane, pentadecyltrimethoxysilane and pentadecyltriethoxysilane, and the like.

Examples of the alkylthiol having the alkyl group having 6 to 22 carbon atoms include: hexyl mercaptan, heptyl mercaptan, octyl mercaptan, nonyl mercaptan, decyl mercaptan, undecyl mercaptan, dodecyl mercaptan, tridecyl mercaptan, tetradecyl mercaptan, pentadecyl mercaptan, and hexadecyl mercaptan, etc. The alkyl mercaptan preferably has a thiol group at the end of the alkyl chain.

Examples of the dialkyl disulfide having an alkyl group of 6 to 22 carbon atoms include: dihexyl disulfide, diheptyl disulfide, dioctyl disulfide, dinonyl disulfide, didecyl disulfide, diundecyl disulfide, didodecyl disulfide, ditridecyl disulfide, ditetradecyl disulfide, dipentadecyl disulfide, and dihexadecyl disulfide, etc.

From the viewpoint of further improving the conduction reliability, it is preferable that the outer surface of the metal part is subjected to a vulcanization resistance treatment using any one of a sulfur-containing compound containing a thioether compound or a thiol compound as a main component, a benzotriazole compound, and a polyoxyethylene ether surfactant. By the vulcanization resistance treatment, a rust-proof film can be formed on the outer surface of the metal part.

Examples of the thioether compound include: a straight chain or branched chain dialkyl sulfide (alkyl sulfide) having about 6 to 40 carbon atoms (preferably about 10 to 40 carbon atoms), such as dihexyl sulfide, diheptyl sulfide, dioctyl sulfide, didecyl sulfide, didodecyl sulfide, ditetradecyl sulfide, dihexadecyl sulfide, and dioctadecyl sulfide; aromatic sulfides having about 12 to 30 carbon atoms such as diphenyl sulfide, phenyl-p-tolyl sulfide, and 4, 4-thiobisbenzenethiol; and thiodicarboxylic acids such as 3,3 '-thiodipropionic acid and 4, 4' -thiodibutanoic acid. The above-mentioned thioether compound is particularly preferably a dialkyl thioether.

Examples of the thiol compound include: and linear or branched alkanethiols having about 4 to 40 carbon atoms (more preferably about 6 to 20 carbon atoms) such as 2-mercaptobenzimidazole, 2-mercaptobenzoxazole, 2-mercaptobenzimidazole, 2-methyl-2-propanethiol, and octadecylthiol. Further, there may be mentioned compounds in which a hydrogen atom bonded to a carbon group of these compounds is substituted with fluorine, and the like.

Examples of the benzotriazole compound include: benzotriazole, benzotriazole salts, methylbenzotriazole, carboxybenzotriazole, benzotriazole derivatives, and the like.

In addition, examples of the anti-tarnish agent include: the trade names of "AC-20", "AC-70", "AC-80" manufactured by North cell industries, Inc. "ENTECH CU-56" manufactured by Meltex corporation, the trade names of "NEWDAINSILVER", "NEWDAINSILVERS-1" manufactured by Katakazakikuwa chemical corporation, the trade name of "B-1057" manufactured by Katakayazakikuwa chemical corporation, and the trade name of "B-1009 NS" manufactured by Katakayazakikuwa chemical corporation.

The method for forming the metal portion on the surface of the base material particle is not particularly limited. Examples of the method for forming the metal portion include: a method using electroless plating; a method using plating; a physical vapor deposition method is utilized; and a method of applying a slurry containing a metal powder or a metal powder and a binder to the surface of the base particles. Since the metal portion can be easily formed, a method using electroless plating is preferable. Examples of the method using physical vapor deposition include vacuum vapor deposition, ion spraying, and ion sputtering.

As a method of forming a projection having a needle-like shape with a tapered tip on the outer surface of the metal portion, the following method can be mentioned.

Examples thereof include: a method based on electroless high-purity nickel plating using hydrazine as a reducing agent; a method based on electroless palladium-nickel alloys using hydrazine as a reducing agent; a method based on electroless CoNiP alloy plating using a hypophosphorous acid compound as a reducing agent; a method based on electroless silver plating using hydrazine as a reducing agent; and a method of plating based on an electroless copper-nickel-phosphorus alloy using a hypophosphorous acid compound as a reducing agent, and the like.

In the method of forming by electroless plating, a catalyst formation step and an electroless plating step are generally performed. Hereinafter, an example of a method of forming an alloy plating layer containing copper and nickel on the surface of the resin particle by electroless plating and forming a projection having a needle-like shape with a tapered tip on the outer surface of the metal portion will be described.

In the above-described catalyst-converting step, a catalyst is formed on the surface of the resin particle, the catalyst serving as a starting point for forming the plating layer by electroless plating.

Examples of the method for forming the catalyst on the surface of the resin particle include: a method in which resin particles are added to a solution containing palladium chloride and tin chloride, and then the surfaces of the resin particles are activated with an acid solution or an alkali solution to deposit palladium on the surfaces of the resin particles; and a method in which resin particles are added to a solution containing palladium sulfate and aminopyridine, and then the surfaces of the resin particles are activated with a solution containing a reducing agent, thereby precipitating palladium on the surfaces of the resin particles. As the reducing agent, a reducing agent containing phosphorus can be used. Further, the reducing agent may be a reducing agent containing phosphorus, whereby a metal portion containing phosphorus can be formed.

In the electroless copper-nickel-phosphorus alloy plating method using a plating solution containing a copper-containing compound, a complexing agent, and a reducing agent in the electroless plating step, it is preferable to use a copper-nickel-phosphorus alloy plating solution containing a hypophosphorous acid compound as a reducing agent, a reaction-initiating metal catalyst containing a nickel-containing compound as a reducing agent, and a nonionic surfactant.

By immersing the resin particles in a copper-nickel-phosphorus alloy plating bath, a copper-nickel-phosphorus alloy can be deposited on the surface of the resin particles on which the catalyst is formed, and a metal portion containing copper, nickel, and phosphorus can be formed.

Examples of the copper-containing compound include copper sulfate, copper chloride, and copper nitrate. The copper-containing compound is preferably copper sulfate.

Examples of the nickel-containing compound include nickel sulfate, nickel chloride, nickel carbonate, nickel sulfamate, and nickel nitrate. The nickel-containing compound is preferably nickel sulfate.

The reducing agent containing phosphorus includes hypophosphorous acid, sodium hypophosphite, and the like. In addition to the above-mentioned reducing agent containing phosphorus, a reducing agent containing boron may be used. Examples of the boron-containing reducing agent include dimethylamine borane, sodium borohydride, and potassium borohydride.

The complexing agent is preferably a monocarboxylic acid complexing agent such as sodium acetate or sodium propionate; a dicarboxylic acid complexing agent such as disodium malonate; tricarboxylic acid complexing agents such as disodium succinate; alcohol acid complexing agents such as lactic acid, DL-malic acid, Rochelle salt, sodium citrate, sodium gluconate, etc.; amino acid complexing agents such as glycine and EDTA; amine complexing agents such as ethylenediamine; organic acid complexing agents such as maleic acid, and salts thereof. These preferred complexing agents may be used alone in 1 kind, or in combination of 2 or more kinds.

Examples of the surfactant include an anionic surfactant, a cationic surfactant, a nonionic surfactant, and an amphoteric surfactant, and a nonionic surfactant is particularly preferable. Preferred nonionic surfactants are polyethers containing ether oxygen atoms. Preferred examples of the nonionic surfactant include polyoxyethylene lauryl ether, polyethylene glycol, polypropylene glycol, polyoxyethylene alkyl ether, polyoxyethylene polyoxypropylene glycol, polyoxyethylene nonylphenyl ether, polyoxyethylene polyoxypropylene alkylamine, and a polyoxyalkylene adduct of ethylenediamine. Preferred examples thereof include polyoxyethylene monoalkyl ethers such as polyoxyethylene monobutyl ether, polyoxypropylene monobutyl ether and polyoxyethylene polyoxypropylene monobutyl ether, polyethylene glycol and ethoxyphenol. The surfactant may be used alone in 1 kind, or may be used in combination of 2 or more kinds. Polyethylene glycol having a molecular weight of about 1000 (e.g., 500 to 2000) is particularly preferable.

In order to form a projection having a needle-like shape with a tapered tip on the outer surface of the metal portion, the molar ratio of the copper compound and the nickel compound is preferably controlled. The amount of the copper compound used is preferably 2 to 100 times in terms of a molar ratio to the nickel compound.

Further, even if the above-mentioned nonionic surfactant or the like is not used, a projection having a needle-like shape can be obtained. In order to form the protrusions having a shape with sharper apex angles and tapered ends, a nonionic surfactant is preferably used, and polyethylene glycol having a molecular weight of about 1000 (e.g., 500 to 2000) is particularly preferably used.

The ratio of the average height (b) of the plurality of projections to the average diameter (c) of the bases of the plurality of projections (average height (b)/average diameter (c)) depends on the thickness of the metal portion, and can be controlled by the immersion time in the plating bath. The plating temperature is preferably 30 ℃ or higher, preferably 100 ℃ or lower, and the immersion time in the plating bath is preferably 5 minutes or longer.

Next, an example of a method of forming a projection having a needle-like shape with a tapered tip on the surface of the resin particle by electroless plating, the silver plating layer, and the outer surface of the metal part will be described.

In the catalyst formation step, a catalyst is formed on the surface of the resin particle, and the catalyst serves as a starting point for forming the plating layer by electroless plating.

Examples of the method of forming the catalyst on the surface of the resin particle include a method of adding the resin particle to a solution containing palladium chloride and tin chloride, and then activating the surface of the resin particle with an acid solution or an alkali solution to deposit palladium on the surface of the resin particle; and a method in which resin particles are added to a solution containing palladium sulfate and aminopyridine, and then the surfaces of the resin particles are activated with a solution containing a reducing agent to deposit palladium on the surfaces of the resin particles. As the reducing agent, a reducing agent containing phosphorus can be used. Further, the metal portion containing phosphorus can be formed by using a reducing agent containing phosphorus as the reducing agent.

In the electroless silver plating process, in the electroless silver plating method using the plating solution containing the silver-containing compound, the complexing agent, and the reducing agent, the silver plating solution containing hydrazine, the nonionic surfactant, and the sulfur-containing organic compound as the reducing agent is preferably used.

By immersing the resin particles in a silver plating bath, silver can be deposited on the surfaces of the resin particles on which the catalyst is formed, and a metal portion containing silver can be formed.

The silver-containing compound is preferably silver potassium cyanide, silver nitrate, silver sodium thiosulfate, silver gluconate, silver-cysteine complex, or silver methanesulfonate.

Examples of the reducing agent include hydrazine, sodium hypophosphite, dimethylamine borane, sodium borohydride, potassium borohydride, formalin, and glucose.

As the reducing agent for forming the projections having a needle-like shape, hydrazine monohydrate, hydrazine hydrochloride, and hydrazine sulfate are preferable.

The complexing agent is preferably a monocarboxylic complexing agent such as sodium acetate or sodium propionate, a dicarboxylic complexing agent such as disodium malonate, a tricarboxylic complexing agent such as disodium succinate, an alkyd complexing agent such as lactic acid, DL-malic acid, Rochelle salt, sodium citrate or sodium gluconate, an amino acid complexing agent such as glycine or EDTA, an amine complexing agent such as ethylenediamine, an organic acid complexing agent such as maleic acid, or a salt thereof. These preferred complexing agents may be used alone in 1 kind, or in combination of 2 or more kinds.

Examples of the surfactant include an anionic surfactant, a cationic surfactant, a nonionic surfactant, and an amphoteric surfactant, and a nonionic surfactant is particularly preferable. Preferred nonionic surfactants are polyethers containing ether oxygen atoms. Preferred nonionic surfactants include: polyoxyethylene lauryl ether, polyethylene glycol, polypropylene glycol, polyoxyethylene alkyl ether, polyoxyethylene polyoxypropylene glycol, polyoxyethylene nonylphenyl ether, polyoxyethylene polyoxypropylene alkylamine, and a polyoxyalkylene adduct of ethylenediamine. Preferred examples thereof include polyoxyethylene monoalkyl ethers such as polyoxyethylene monobutyl ether, polyoxypropylene monobutyl ether and polyoxyethylene polyoxypropylene monobutyl ether, polyethylene glycol and ethoxyphenol. The surfactant may be used alone in 1 kind, or may be used in combination of 2 or more kinds. Polyethylene glycol having a molecular weight of about 1000 (e.g., 500 to 2000) is particularly preferable.

Further, even if the above-mentioned nonionic surfactant or the like is not used, a projection having a needle-like shape can be obtained. In order to form the protrusion having a sharp apex angle and a tapered shape, a nonionic surfactant is preferably used, and polyethylene glycol having a molecular weight of about 1000 (for example, 500 to 2000) is particularly preferably used.

Examples of the sulfur-containing organic compound include a thioether, an organic compound having a sulfonic acid group, a thiourea compound, and a benzimidazole compound. Examples of the thioether or the organic compound having a sulfonic acid group include: n, N-dimethyl-dithiocarbamic acid- (3-sulfopropyl) ester, 3-mercapto-propylsulfonic acid sodium salt, 3-mercapto-1-propanesulfonic acid potassium salt, dithio-o-ethyl carbonate, disulfopropyldithium ether, bis- (3-sulfopropyl) -disulfide disodium salt, 3- (benzothiazolyl-s-thio) propylsulfonic acid sodium salt, pyridinium propyl sulfobetaine, 1-sodium-3-mercaptopropane-1-sulfonate, N-dimethyl-dithiocarbamic acid- (3-sulfoethyl) ester, 3-mercapto-ethylpropylsulfonic acid- (3-sulfoethyl) ester, N-dimethyl-dithiocarbamic acid- (3-sulfoethyl) ester, N-mercapto-propylsulfonic acid- (3-sulfoethyl) ester, N-dimethyl-dithiocarbamic acid, 3-mercapto-ethylsulfonic acid sodium salt, 3-mercapto-1-ethanesulfonic acid potassium salt, dithio-o-ethyl carbonate-s-ester, disulfoethyldisulfide, 3- (benzothiazolyl-s-thio) ethylsulfonic acid sodium salt, pyridinium ethylsulfobetaine, 1-sodium-3-mercaptoethane-1-sulfonate, thiourea compound, and the like. Examples of the thiourea compound include thiourea, 1, 3-dimethylthiourea, trimethylthiourea, diethylthiourea, and allylthiourea.

Further, even if the above-mentioned sulfur-containing organic compound or the like is not used, a projection having a needle-like shape can be obtained. In order to form the protrusions having a shape with a sharper apex and a tapered tip, it is preferable to use a sulfur-containing organic compound, and particularly, thiourea.

The ratio of the average height (b) of the plurality of projections to the average diameter (c) of the bases of the plurality of projections (average height (b)/average diameter (c)) depends on the thickness of the metal portion and can be controlled according to the immersion time in the plating bath. The plating temperature is preferably 30 ℃ or higher, preferably 100 ℃ or lower, and the immersion time in the plating bath is preferably 5 minutes or longer.

Next, an example of a method of forming a high-purity nickel plating layer on the surface of the resin particle by electroless plating and forming a projection having a needle-like shape with a tapered tip on the outer surface of the metal part will be described.

In the above-described catalyst formation step, a catalyst is formed on the surface of the resin particle, the catalyst serving as a starting point for forming the plating layer by electroless plating.

Examples of the method for forming the catalyst on the surface of the resin particle include: a method in which resin particles are added to a solution containing palladium chloride and tin chloride, and then the surfaces of the resin particles are activated with an acid solution or an alkali solution to precipitate palladium on the surfaces of the resin particles; and a method in which resin particles are added to a solution containing palladium sulfate and aminopyridine, and then the surfaces of the resin particles are activated with a solution containing a reducing agent, thereby precipitating palladium on the surfaces of the resin particles. As the reducing agent, a reducing agent containing phosphorus can be used. Further, the reducing agent may be a reducing agent containing phosphorus, whereby a metal portion containing phosphorus can be formed.

In the electroless plating step, in the electroless high-purity nickel plating method using the plating solution containing the nickel-containing compound, the complexing agent, and the reducing agent, it is preferable to use a high-purity nickel plating solution containing hydrazine as the reducing agent.

By immersing the resin particles in a high-purity nickel plating bath, high-purity nickel can be plated and precipitated on the surface of the resin particles on which the catalyst is formed, and a metal part of high-purity nickel can be formed.

Examples of the nickel-containing compound include nickel sulfate, nickel chloride, nickel carbonate, nickel sulfamate, and nickel nitrate. The nickel-containing compound is preferably nickel chloride.

Examples of the reducing agent include hydrazine monohydrate, hydrazine hydrochloride, and hydrazine sulfate. The reducing agent is preferably hydrazine monohydrate.

Examples of the complexing agent include: monocarboxylic acid complexing agents such as sodium acetate and sodium propionate, dicarboxylic acid complexing agents such as disodium malonate, tricarboxylic acid complexing agents such as disodium succinate, alkyd acid complexing agents such as lactic acid, DL-malic acid, Rochelle salt, sodium citrate and sodium gluconate, amino acid complexing agents such as glycine and EDTA, amine complexing agents such as ethylenediamine, and organic acid complexing agents such as maleic acid. The complexing agent is preferably glycine as an amino acid complexing agent.

In order to form a projection having a needle-like shape with a tapered tip on the outer surface of the metal part, the pH of the plating solution is preferably adjusted to 8.0 or more. In an electroless plating solution using hydrazine as a reducing agent, when nickel is reduced by an oxidation reaction of hydrazine, a sharp decrease in pH is caused. In order to suppress the above-mentioned sharp decrease in pH, a buffer such as phosphoric acid, boric acid, or carbonic acid is preferably used. The buffering agent is preferably boric acid having a buffering effect of ph8.0 or more.

The ratio of the average height (b) of the plurality of projections to the average diameter (c) of the base of the plurality of projections (average height (b)/average diameter (c)) depends on the thickness of the metal portion and can be controlled according to the immersion time in the plating bath. The plating temperature is preferably 30 ℃ or higher, preferably 100 ℃ or lower, and the immersion time in the plating bath is preferably 5 minutes or longer.

Next, an example of a method of forming a palladium-nickel alloy plating layer on the surface of the resin particle by electroless plating and forming a projection having a sharp needle-like shape on the outer surface of the metal part will be described.

Examples of the method for forming the catalyst on the surface of the resin particle include: a method in which resin particles are added to a solution containing palladium chloride and tin chloride, and then the surfaces of the resin particles are activated with an acid solution or an alkali solution to deposit palladium on the surfaces of the resin particles; and a method in which resin particles are added to a solution containing palladium sulfate and aminopyridine, and then the surfaces of the resin particles are activated with a solution containing a reducing agent, thereby precipitating palladium on the surfaces of the resin particles. As the reducing agent, a reducing agent containing phosphorus can be used. Further, the metal portion containing phosphorus can be formed by using a reducing agent containing phosphorus as the reducing agent.

In the electroless palladium-nickel plating method using a plating solution containing a nickel-containing compound, a palladium compound, a stabilizer, a complexing agent, and a reducing agent in the electroless plating step, a palladium-nickel alloy plating solution containing hydrazine as a reducing agent is preferably used.

By immersing the resin particles in a palladium-nickel alloy plating bath, palladium-nickel alloy plating can be deposited on the surfaces of the resin particles on which the catalyst is formed, and a metal portion of palladium-nickel can be formed.

Examples of the palladium-containing compound include: dichlorodiaminepalladium (II), palladium chloride, dichlorodiaminepalladium (II), dinitrodiaminepalladium (II), tetraamminepalladium (II) nitrate, tetraamminepalladium (II) sulfate, diaminepalladium (II) oxalate, tetraamminepalladium (II) chloride and the like. The palladium-containing compound is preferably palladium chloride.

Examples of the stabilizer include lead compounds, bismuth compounds, thallium compounds, and the like. Specific examples of these compounds include sulfates, carbonates, acetates, nitrates, hydrochlorides and the like of metals (lead, bismuth and thallium) constituting the compounds. In consideration of the influence on the environment, a bismuth compound or a thallium compound is preferable. These preferred stabilizers may be used alone in 1 kind, or in combination of 2 or more kinds.

Examples of the complexing agent include: monocarboxylic acid complexing agents such as sodium acetate and sodium propionate, dicarboxylic acid complexing agents such as disodium malonate, tricarboxylic acid complexing agents such as disodium succinate, hydroxy acid complexing agents such as lactic acid, DL-malic acid, Rochelle salt, sodium citrate and sodium gluconate, amino acid complexing agents such as glycine and EDTA, amine complexing agents such as ethylenediamine, and organic acid complexing agents such as maleic acid. The complexing agent is preferably ethylenediamine as an amino acid complexing agent.

In order to form a projection having a needle-like shape with a tapered tip on the outer surface of the metal part, the pH of the plating solution is preferably adjusted from 8.0 to 10.0. If the pH is 7.5 or less, the stability of the plating solution is lowered and the bath is decomposed, and therefore, it is preferable to set the pH to 8.0 or more.

Next, an example of a method of forming an alloy plating layer containing cobalt and nickel on the surface of the resin particle by electroless plating and forming a projection having a needle-like shape with a tapered tip on the outer surface of the metal portion will be described.

Examples of the method of forming the catalyst on the surface of the resin particle include a method of adding the resin particle to a solution containing palladium chloride and tin chloride, and then activating the surface of the resin particle with an acid solution or an alkali solution to deposit palladium on the surface of the resin particle; and a method in which resin particles are added to a solution containing palladium sulfate and aminopyridine, and then the surfaces of the resin particles are activated with a solution containing a reducing agent, thereby precipitating palladium on the surfaces of the resin particles. As the reducing agent, a reducing agent containing phosphorus can be used. Further, the metal portion containing phosphorus can be formed by using a reducing agent containing phosphorus as the reducing agent.

In the electroless cobalt-nickel-phosphorus alloy plating method using a plating solution containing a cobalt-containing compound, an inorganic additive, a complexing agent, and a reducing agent in the electroless plating step, it is preferable to use a cobalt-nickel-phosphorus alloy plating solution containing a hypophosphorous acid compound as a reducing agent and a reaction-initiating metal catalyst containing a cobalt-containing compound as a reducing agent.

By immersing the resin particles in a cobalt-nickel-phosphorus alloy plating bath, a cobalt-nickel-phosphorus alloy can be deposited on the surfaces of the resin particles on which the catalyst is formed, and a metal portion containing cobalt, nickel, and phosphorus can be formed.

The cobalt-containing compound is preferably cobalt sulfate, cobalt chloride, cobalt nitrate, cobalt acetate, or cobalt carbonate. The cobalt-containing compound is more preferably cobalt sulfate.

The complexing agent is preferably a monocarboxylic complexing agent such as sodium acetate or sodium propionate, a dicarboxylic complexing agent such as disodium malonate, a tricarboxylic complexing agent such as disodium succinate, a hydroxy acid complexing agent such as lactic acid, DL-malic acid, Rochelle salt, sodium citrate or sodium gluconate, an amino acid complexing agent such as glycine or EDTA, an amine complexing agent such as ethylenediamine, an organic acid complexing agent such as maleic acid, or a salt thereof. These preferred complexing agents may be used alone in 1 kind, or in combination of 2 or more kinds.

The inorganic additive is preferably ammonium sulfate, ammonium chloride, or boric acid. These preferred inorganic additives may be used alone in an amount of 1 kind, or in combination of 2 or more kinds. The inorganic additive is considered to have an action of promoting the deposition of the electroless cobalt plating layer.

In order to form a projection having a needle-like shape with a tapered tip on the outer surface of the metal portion, the molar ratio of the cobalt compound and the nickel compound is preferably controlled. The amount of the cobalt compound used is preferably 2 to 100 times in terms of a molar ratio relative to the nickel compound.

Further, even if the above inorganic additive is not used, a projection having a needle-like shape can be obtained. In order to form the protrusions having a shape with a smaller apex angle and a sharply tapered tip, an inorganic additive is preferably used, and ammonium sulfate is particularly preferably used.

The thickness of the entire metal portion in the portion where the protrusion is not present is preferably 5nm or more, more preferably 10nm or more, further preferably 20nm or more, particularly preferably 50nm or more, preferably 1000nm or less, more preferably 800nm or less, further preferably 500nm or less, and particularly preferably 400nm or less. The thickness of the entire metal portion in the portion where the convex portion is not present is preferably 5nm or more, more preferably 10nm or more, further preferably 20nm or more, particularly preferably 50nm or more, preferably 1000nm or less, more preferably 800nm or less, further preferably 500nm or less, and particularly preferably 400nm or less. When the thickness of the entire metal portion is not less than the lower limit, peeling of the metal portion can be suppressed. When the thickness of the entire metal portion is not more than the upper limit, the difference in thermal expansion coefficient between the base particle and the metal portion is small, and the metal portion is less likely to be peeled off from the base particle. The thickness of the metal part refers to the thickness of the entire metal part (the total thickness of the first metal part and the second metal part) when the metal part includes a plurality of metal parts (the first metal part and the second metal part).

When the metal portion has a plurality of metal portions, the thickness of the metal portion in the outermost layer at a portion where the protrusion is not present is preferably 1nm or more, more preferably 10nm or more, preferably 500nm or less, and more preferably 100nm or less. When the metal part has a plurality of metal parts, the thickness of the metal part in the non-convex part of the outermost layer is preferably 1nm or more, more preferably 10nm or more, preferably 500nm or less, and more preferably 100nm or less. When the thickness of the outermost metal portion is not less than the lower limit and not more than the upper limit, the outermost metal portion can be uniformly coated, the corrosion resistance can be sufficiently improved, and the connection resistance between the electrodes can be sufficiently reduced. In addition, when the outermost layer is expensive as compared with the metal part of the inner layer, the thinner the thickness of the outermost layer is, the lower the cost is.

The thickness of the metal part can be measured by observing a cross section of the metal-containing particle using, for example, a Transmission Electron Microscope (TEM).

[ core Material ]

The metal-containing particles preferably include a plurality of core materials that swell a surface of the metal part, and more preferably include a plurality of core materials that swell a surface of the metal part so that a plurality of convex portions or a plurality of protrusions are formed in the metal part. Since the core material is embedded in the metal portion, the metal portion easily has a plurality of the convex portions or a plurality of protrusions on the outer surface. However, the core material is not necessarily used to form the convex portions or protrusions on the outer surfaces of the metal-containing particles and the metal portions. For example, as a method of forming the convex portions or protrusions without using the core material by electroless plating, there is a method of generating metal nuclei by electroless plating, attaching the metal nuclei to the surface of the base particles or the metal portion, and further forming the metal portion by electroless plating.

Examples of the method for forming the convex portions or protrusions include a method in which a core material is attached to the surface of a base particle, and then a metal portion is formed by electroless plating; and a method of forming a metal portion on the surface of the base particle by electroless plating, then attaching the core material, and further forming a metal portion by electroless plating.

Examples of a method for disposing the core material on the surface of the base material particle include a method in which the core material is added to a dispersion of the base material particle, and the core material is aggregated and accumulated by, for example, van der waals force, and adhered to the surface of the base material particle; and a method in which a core material is added to a container in which the base material particles are placed, and the core material is attached to the surface of the base material particles by a mechanical action caused by rotation of the container or the like. Among these, in order to easily control the amount of the attached core material, a method of aggregating and accumulating the core material and attaching it to the surface of the base material particles in the dispersion is preferable.

Since the core material is embedded in the metal portion, the metal portion easily has a plurality of the convex portions or a plurality of protrusions on the outer surface. However, the core material is not necessarily used to form the convex portions or the protrusions on the conductive surface of the metal-containing particles and the surface of the metal portion.

Examples of the method for forming the convex portion or the protrusion include: a method of forming a metal portion by electroless plating after attaching a core material to the surface of the base material particle; a method of forming a metal portion on the surface of the base material particle by electroless plating, then attaching a core material thereto, and further forming a metal portion by electroless plating; and a method of adding a core material to the surface of the base material particle by electroless plating at a stage during the formation of the metal part.

Examples of the material of the core material include an electrically conductive material and a non-electrically conductive material. Examples of the conductive material include conductive nonmetal such as metal, metal oxide, and graphite, and conductive polymer. The conductive polymer may be polyacetylene or the like. Examples of the nonconductive substance include silica, alumina, barium titanate, and zirconia. Among them, metals are preferable because conductivity can be improved and connection resistance can be effectively reduced. The core material is preferably a metal particle. As the metal as the material of the core material, metals listed as the material of the conductive material can be suitably used.

Specific examples of the material of the core material include: barium titanate (mohs hardness 4.5), nickel (mohs hardness 5), silica (silica, mohs hardness 6-7), titanium oxide (mohs hardness 7), zirconium oxide (mohs hardness 8-9), kj mohs hardness 9), tungsten carbide (mohs hardness 9), diamond (mohs hardness 10), and the like. The inorganic particles are preferably nickel, silica, titania, zirconia, alumina, tungsten carbide, or diamond, more preferably silica, titania, zirconia, alumina, tungsten carbide, or diamond, still more preferably titania, zirconia, alumina, tungsten carbide, or diamond, and particularly preferably zirconia, alumina, tungsten carbide, or diamond. The mohs hardness of the material of the core material is preferably 5 or more, more preferably 6 or more, further preferably 7 or more, and particularly preferably 7.5 or more.

The shape of the core material is not particularly limited. The shape of the core material is preferably a block. Examples of the core material include: particulate masses, aggregates formed by aggregating a plurality of fine particles, irregular masses, and the like.

The average diameter (average particle diameter) of the core material is preferably 0.001 μm or more, more preferably 0.05 μm or more, preferably 0.9 μm or less, and more preferably 0.2 μm or less. When the average diameter of the core material is not less than the lower limit and not more than the upper limit, the connection resistance between the electrodes is effectively lowered.

The "average diameter (average particle diameter)" of the core material means an average diameter (number average particle diameter). The average diameter of the core material is determined by observing 50 arbitrary core materials with an electron microscope or an optical microscope and calculating the average diameter.

[ insulating Material ]

The metal-containing particles of the present invention preferably include an insulating material disposed on the outer surface of the metal part. In this case, when the metal-containing particles are used for connection between electrodes, short-circuiting between adjacent electrodes can be prevented. Specifically, when a plurality of metal-containing particles are in contact with each other, since an insulating material is present between a plurality of electrodes, it is possible to prevent a short circuit between laterally adjacent electrodes, rather than between upper and lower electrodes. When the metal-containing particles are connected between the electrodes, the insulating material between the metal part of the metal-containing particles and the electrodes can be easily removed by pressurizing the metal-containing particles with two electrodes. Since the metal part has a plurality of protrusions on the outer surface, the insulating material between the metal part of the metal-containing particles and the electrode can be easily removed. In addition, in the case where the metal part has a plurality of convex portions on the outer surface, the insulating material between the metal part of the metal-containing particles and the electrode can be easily removed.

The insulating material is preferably insulating particles because the insulating material can be more easily removed when pressure-bonding is performed between the electrodes.

Specific examples of the insulating resin as a material of the insulating substance include: polyolefin compounds, (meth) acrylate polymers, (meth) acrylate copolymers, block polymers, thermoplastic resins, crosslinked products of thermoplastic resins, thermosetting resins, water-soluble resins, and the like.

Examples of the polyolefin compound include: polyethylene, ethylene-vinyl acetate copolymers, ethylene-acrylate copolymers, and the like. Examples of the (meth) acrylate polymer include polymethyl (meth) acrylate, polyethyl (meth) acrylate, and polybutyl (meth) acrylate. Examples of the block polymer include: polystyrene, styrene-acrylate copolymers, SB type styrene-butadiene block copolymers, and SBs type styrene-butadiene block copolymers, and hydrogenated products thereof. Examples of the thermoplastic resin include vinyl polymers and vinyl copolymers. Examples of the thermosetting resin include epoxy resin, phenol resin, melamine resin, and the like. Examples of the water-soluble resin include: polyvinyl alcohol, polyacrylic acid, polyacrylamide, polyvinyl pyrrolidone, polyethylene oxide, methyl cellulose, and the like. Among them, water-soluble resins are preferable, and polyvinyl alcohol is more preferable.

Examples of the method of disposing the insulating material on the surface of the metal part include a chemical method and a physical or mechanical method. Examples of the chemical method include: interfacial polymerization, suspension polymerization in the presence of particles, emulsion polymerization, and the like. Examples of the physical or mechanical method include methods using spray drying, hybridization, electrostatic adhesion, spraying, dipping, and vacuum deposition. Among them, a method of disposing the insulating material on the surface of the metal part via a chemical bond is preferable in terms of the insulating material being less likely to be detached.

The outer surface of the metal part and the surface of the insulating material (insulating particles and the like) may be coated with a compound having a reactive functional group. The outer surface of the metal portion and the surface of the insulating material may be directly chemically bonded, or may be indirectly chemically bonded by a compound having a reactive functional group. After a carboxyl group is introduced to the outer surface of the metal part, the carboxyl group can be chemically bonded to a functional group on the surface of the insulating material via a polymer electrolyte such as polyethyleneimine.

The average diameter (average particle diameter) of the insulating material may be appropriately selected depending on the particle diameter of the metal-containing particles, the use of the metal-containing particles, and the like. The average diameter (average particle diameter) of the insulating material is preferably 0.005 μm or more, more preferably 0.01 μm or more, preferably 1 μm or less, and more preferably 0.5 μm or less. When the average diameter of the insulating material is not less than the lower limit, the metal portions of the plurality of metal-containing particles are less likely to contact each other when the metal-containing particles are dispersed in the binder resin. When the average diameter of the insulating material is not more than the upper limit, it is not necessary to increase the pressure excessively or to heat the insulating material to a high temperature in order to remove the insulating material between the electrode and the metal-containing particles in the connection between the electrodes.

The "average diameter (average particle diameter)" of the insulating material means a number average diameter (number average particle diameter). The average diameter of the insulating material is determined using a particle size distribution measuring apparatus or the like.

(particle assembly)

The metal-containing particles of the present invention can be formed into a particle assembly shown in fig. 15 by melting and then solidifying the projections of the metal part as described above. Such a particle assembly can be used as a novel material for improving connection reliability to a level higher than that of conventional metal-containing particles. That is, the present inventors have found the following invention as a novel connecting material.

1) The plurality of metal-containing particles (also referred to as metal-containing particle bodies, which are different from the metal-containing particles of the present invention) are particle connected bodies connected via metal-containing columnar connecting portions.

2) The columnar connecting portion is a particle connecting body of 1) above containing the same kind of metal as that contained in the metal-containing particle.

3) The metal-containing particles constituting the particle assembly are particle assemblies of 1) or 2) above derived from the metal-containing particles of the present invention.

4) The metal-containing particles and the columnar connecting portions constituting the particle connected body are particle connected bodies of any one of the above 1) to 3) formed by melting and solidifying the protrusions of the metal-containing particles of the present invention.

5) The columnar connecting portion is a particle connecting body of any one of the above 1) to 4) derived from the protrusion of the metal-containing particle of the present invention.

The particle connected body of the present invention can be produced by the above-described method, but the production method is not limited to the above-described method. For example, the metal-containing particles and the columnar bodies may be produced separately, and the metal-containing particles may be connected by the columnar bodies to form columnar connection portions.

The columnar coupling portion may be a columnar coupling portion or a polygonal columnar coupling portion, and the central portion of the column may be thickened or thinned.

In the columnar connecting portion, a diameter (d) of a circumscribed circle of a connecting surface with the metal-containing particle is preferably 3nm or more, more preferably 100nm or more, preferably 10000nm or less, more preferably 1000nm or less.

In the columnar connecting portion, the length (l) of the columnar connecting portion is preferably 3nm or more, more preferably 100nm or more, preferably 10000nm or less, and more preferably 1000nm or less.

In the columnar connecting portion, a ratio ((d)/(l)) of a length (l) of the columnar connecting portion to a diameter (d) of a circumscribed circle of a connecting surface of the metal-containing particle is preferably 0.001 or more, more preferably 0.1 or more, preferably 100 or less, and more preferably 10 or less.

The particle assembly of the present invention may be an assembly of 2 metal-containing particles as shown in fig. 15, or may be an assembly of 3 or more metal-containing particles.

(connecting Material)

The connecting material of the present invention is preferably used for forming a connecting portion for connecting two connection target members together. The connecting material contains the metal-containing particles and a resin. The connecting material is preferably used for forming the connecting portion by melting and then solidifying the distal ends of the protrusions of the metal portion of the plurality of metal-containing particles.

The resin is not particularly limited. The resin is a binder for dispersing the metal-containing particles. The resin preferably contains a thermoplastic resin or a curable resin, and more preferably contains a curable resin. Examples of the curable resin include a photocurable resin and a thermosetting resin. The photocurable resin preferably contains a photocurable resin and a photopolymerization initiator. The thermosetting resin preferably contains a thermosetting resin and a thermosetting agent. Examples of the resin include vinyl resins, thermoplastic resins, curable resins, thermoplastic block copolymers, and elastomers. The resin may be used alone in 1 kind, or in combination with 2 or more kinds.

Examples of the vinyl resin include vinyl acetate resins, acrylic resins, styrene resins, and the like. Examples of the thermoplastic resin include polyolefin resins, ethylene-vinyl acetate copolymers, and polyamide resins. Examples of the curable resin include epoxy resins, polyurethane resins, polyimide resins, and unsaturated polyester resins. The curable resin may be a room temperature curable resin, a thermosetting resin, a photocurable resin, or a moisture curable resin. Examples of the thermoplastic block copolymer include: styrene-butadiene-styrene block copolymers, styrene-isoprene-styrene block copolymers, hydrogenated products of styrene-butadiene-styrene block copolymers, hydrogenated products of styrene-isoprene-styrene block copolymers, and the like. Examples of the elastomer include styrene-butadiene copolymer rubber, acrylonitrile-styrene block copolymer rubber, and the like.

When the projection of the metal portion contains a metal oxide, a reducing agent is preferably used. Examples of the reducing agent include an alcohol compound (a compound having an alcoholic hydroxyl group), a carboxyoxy compound (a compound having a carboxyl group), and an amine compound (a compound having an amino group). The reducing agent may be used alone in 1 kind, or may be used in combination in 2 or more kinds.

Examples of the alcohol compound include alkyl alcohols. Specific examples of the alcohol compound include: ethanol, propanol, butanol, pentanol, hexanol, heptanol, octanol, nonanol, decanol, undecanol, dodecanol, tridecanol, tetradecanol, pentadecanol, hexadecanol, heptadecanol, octadecanol, nonadecanol, and eicosanol, and the like. The alcohol compound is not limited to a primary alcohol compound, and a secondary alcohol compound, a tertiary alcohol compound, an alkanediol, and an alcohol compound having a cyclic structure may be used. As the alcohol compound, many compounds having an alcohol group such as ethylene glycol and triethylene glycol can be used. As the alcohol compound, compounds such as citric acid, ascorbic acid, and glucose can be used.

Examples of the carboxylic acid compound include alkyl carboxylic acids. Specific examples of the carboxylic acid compound include butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, undecanoic acid, dodecanoic acid, tridecanoic acid, tetradecanoic acid, pentadecanoic acid, hexadecanoic acid, heptadecanoic acid, octadecanoic acid, nonadecanoic acid, and eicosanoic acid. The carboxylic acid compound is not limited to the primary carboxylic acid type compound, and a secondary carboxylic acid type compound, a tertiary carboxylic acid type compound, a dicarboxylic acid, and a carboxylic acid compound having a cyclic structure may be used.

The amine compound may be an alkylamine. Specific examples of the amine compound include butylamine, pentylamine, hexylamine, heptylamine, octylamine, nonylamine, decylamine, undecylamine, dodecylamine, tridecylamine, tetradecylamine, pentadecylamine, hexadecylamine, heptadecylamine, octadecylamine, nonadecylamine, and eicosylamine. In addition, the amine compound may have a branched structure. Examples of the amine compound having a branched structure include 2-ethylhexylamine and 1, 5-dimethylhexylamine. The amine compound is not limited to the primary amine compound, and a secondary amine compound, a tertiary amine compound, and an amine compound having a cyclic structure can be used.

The reducing agent may be an organic substance having an aldehyde group, an ester group, a sulfonyl group, a ketone group, or the like, or an organic substance such as a carboxylic acid metal salt. The metal carboxylate is also used as a precursor of the metal particles, and on the other hand, is also used as a reducing agent of the metal oxide particles because it contains an organic substance.

The connecting material may contain various additives such as a filler, an extender, a softener, a plasticizer, a polymerization catalyst, a curing catalyst, a colorant, an antioxidant, a heat stabilizer, a light stabilizer, an ultraviolet absorber, a lubricant, an antistatic agent, and a flame retardant in addition to the metal-containing particles and the resin.

The above-mentioned connecting material is preferably used for conductive connection, and is preferably a conductive connecting material. The above-mentioned connection material is preferably used for anisotropic conductive connection, and is preferably an anisotropic conductive connection material. The connecting material can be used as a paste, a film, or the like. When the connecting material is a film, a film containing no metal-containing particles may be stacked on a film containing metal-containing particles. The paste is preferably a conductive paste, and more preferably an anisotropic conductive paste. The film is preferably a conductive film, and more preferably an anisotropic conductive film.

The content of the resin is preferably 1 wt% or more, more preferably 5 wt% or more, may be 10 wt% or more, may be 30 wt% or more, may be 50 wt% or more, may be 70 wt% or more, preferably 99.99 wt% or less, and more preferably 99.9 wt% or less, in 100 wt% of the connecting material. When the content of the resin is not less than the lower limit and not more than the upper limit, the connection reliability is further improved.

The content of the metal-containing particles is preferably 0.01 wt% or more, more preferably 0.1 wt% or more, preferably 99 wt% or less, more preferably 95 wt% or less, and may be 80 wt% or less, may be 60 wt% or less, may be 40 wt% or less, may be 20 wt% or less, and may be 10 wt% or less in 100 wt% of the connecting material. When the content of the metal-containing particles is not less than the lower limit and not more than the upper limit, the connection reliability is further improved. In addition, when the content of the metal-containing particles is not less than the lower limit and not more than the upper limit, the metal-containing particles can be sufficiently present between the first connection target member and the second connection target member, and the use of the metal-containing particles can further suppress the narrowing of the gap portion between the first connection target member and the second connection target member. Therefore, the heat radiation property of the connection portion can be suppressed from being partially lowered.

The connecting material may contain particles containing a metal atom which do not have the base material particles, unlike the metal-containing particles.

Examples of the metal atom-containing particles include metal particles and metal compound particles. The metal compound particles contain a metal atom and an atom other than the metal atom. Specific examples of the metal compound particles include metal oxide particles, metal carbonate particles, metal carboxylate particles, and metal complex particles. The metal compound particles are preferably metal oxide particles. For example, the metal oxide particles are sintered after being converted into metal particles by heating at the time of connection in the presence of a reducing agent. The metal oxide particles are precursors of metal particles. Examples of the metal carboxylate particles include metal acetate particles.

Examples of the metal constituting the metal particles and the metal oxide particles include silver, copper, nickel, gold, and the like. Silver or copper is preferred, and silver is particularly preferred. Therefore, the metal particles are preferably silver particles or copper particles, and more preferably silver particles. The metal oxide particles are preferably silver oxide particles or copper oxide particles, and more preferably silver oxide particles. When silver particles and silver oxide particles are used, the amount of residue after connection is small and the volume reduction rate is very small. The silver oxide in the silver oxide particles includes Ag₂O and AgO.

The above-mentioned metal atom-containing particles are preferably sintered by heating at a temperature of less than 400 ℃. The temperature (sintering temperature) at which the metal atom-containing particles are sintered is more preferably 350 ℃ or less, and is preferably 300 ℃ or more. When the temperature at which the metal atom-containing particles are sintered is not more than the upper limit or less than the upper limit, sintering can be efficiently performed, energy required for sintering can be further reduced, and the environmental load can be reduced.

The connecting material containing the metal atom-containing particles is preferably a connecting material containing metal particles having an average particle diameter of 1nm or more and 100nm or less, or a connecting material containing metal oxide particles having an average particle diameter of 1nm or more and 50 μm or less and a reducing agent. When such a bonding material is used, the metal atom-containing particles can be sintered well by heating at the time of bonding. The average particle diameter of the metal oxide particles is preferably 5 μm or less. The particle size of the metal atom-containing particle is a diameter when the metal atom-containing particle is a regular sphere, and a maximum diameter when the metal atom-containing particle is not a regular sphere.

The content of the metal atom-containing particles in 100 wt% of the connecting material is preferably 10 wt% or more, more preferably 30 wt% or more, further preferably 50 wt% or more and 100 wt% or less, preferably 99 wt% or less, and more preferably 90 wt% or less. The total amount of the connecting material may be the metal atom-containing particles. When the content of the metal atom-containing particles is not less than the lower limit, the metal atom-containing particles can be sintered more densely. As a result, heat dissipation and heat resistance at the connection portion are also improved.

When the metal atom-containing particles are metal oxide particles, a reducing agent is preferably used. Examples of the reducing agent include an alcohol compound (a compound having an alcoholic hydroxyl group), a carboxylic acid compound (a compound having a carboxyl group), and an amine compound (a compound having an amino group). The reducing agent may be used alone in 1 kind, or may be used in combination in 2 or more kinds.

Examples of the alcohol compound include alkyl alcohols. Specific examples of the alcohol compound include: ethanol, propanol, butanol, pentanol, hexanol, heptanol, octanol, nonanol, decanol, undecanol, dodecanol, tridecanol, tetradecanol, pentadecanol, hexadecanol, heptadecanol, octadecanol, nonadecanol, and eicosanol, and the like. The alcohol compound is not limited to a primary alcohol compound, and a secondary alcohol compound, a tertiary alcohol compound, an alkane diol, and an alcohol compound having a cyclic structure may be used. As the alcohol compound, a compound having a large number of alcohol groups such as ethylene glycol and triethylene glycol can be used. As the alcohol compound, compounds such as citric acid, ascorbic acid, and glucose can be used.

Examples of the carboxylic acid compound include alkyl carboxylic acids. Specific examples of the carboxylic acid compound include: butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, undecanoic acid, dodecanoic acid, tridecanoic acid, tetradecanoic acid, pentadecanoic acid, hexadecanoic acid, heptadecanoic acid, octadecanoic acid, nonadecanoic acid, and eicosanoic acid, and the like. The carboxylic acid compound is not limited to the primary carboxylic acid type compound, and a secondary carboxylic acid type compound, a tertiary carboxylic acid type compound, a dicarboxylic acid, and a carboxylic acid compound having a cyclic structure may be used.

The amine compound may be an alkylamine. Specific examples of the amine compound include butylamine, pentylamine, hexylamine, heptylamine, octylamine, nonylamine, decylamine, undecylamine, dodecylamine, tridecylamine, tetradecylamine, pentadecylamine, hexadecylamine, heptadecylamine, octadecylamine, nonadecylamine, and eicosylamine. In addition, the amine compound may have a branched structure. Examples of the amine compound having a branched structure include 2-ethylhexylamine and 1, 5-dimethylhexylamine. The amine compound is not limited to the primary amine compound, and a secondary amine compound, a tertiary amine compound, and an amine compound having a cyclic structure may be used.

When a reducing agent having a melting point lower than the sintering temperature (bonding temperature) of the metal atom-containing particles is used, aggregation tends to occur during bonding, and voids tend to be generated in the bonded portion. By using the metal carboxylate, the metal carboxylate is not melted by heating at the time of bonding, and therefore, generation of voids can be suppressed. In addition to the metal carboxylate, a metal compound containing an organic substance may be used as the reducing agent.

In the case where the reducing agent is used, the content of the reducing agent is preferably 1% by weight or more, more preferably 10% by weight or more, preferably 90% by weight or less, more preferably 70% by weight or less, and further preferably 50% by weight or less, in 100% by weight of the connecting material. When the content of the reducing agent is not less than the lower limit, the metal atom-containing particles can be sintered more densely. As a result, heat dissipation and heat resistance in the joint portion are also improved.

The content of the metal oxide particles is preferably 10% by weight or more, more preferably 30% by weight or more, further preferably 60% by weight or more, preferably 99.99% by weight or less, more preferably 99.9% by weight or less, further preferably 99.5% by weight or less, further preferably 99% by weight or less, particularly preferably 90% by weight or less, and most preferably 80% by weight or less, in 100% by weight of the connecting material.

When the connecting material is a paste, the binder used for the paste is not particularly limited. The binder is preferably disappeared when the metal atom-containing particles are sintered. The above-mentioned binders may be used alone in 1 kind, or may be used in combination in 2 or more kinds.

Specific examples of the binder include, as the solvent: aliphatic solvents, ketone solvents, aromatic solvents, ester solvents, ether solvents, alcohol solvents, olefin solvents, petroleum solvents, and the like.

Examples of the aliphatic solvent include cyclohexane, methylcyclohexane, and ethylcyclohexane. Examples of the ketone solvent include acetone and methyl ethyl ketone. Examples of the aromatic solvent include toluene and xylene. Examples of the ester solvent include ethyl acetate, butyl acetate, and isopropyl acetate. Examples of the ether solvent include Tetrahydrofuran (THF), dioxane, and the like. Examples of the alcohol solvent include ethanol and butanol. The olefin-based solvent includes olefin oil, naphthenic oil, and the like. Examples of the petroleum solvent include mineral turpentine, naphtha, and the like.

(connection structure)

The connection structure of the present invention includes: the connector includes a first connection object member, a second connection object member, and a connecting portion that connects the first connection object member and the second connection object member together. In the connection structure of the present invention, the connection portion is formed of the metal-containing particle or the connection material. The material of the connecting part is the metal-containing particles or the connecting material.

The method for manufacturing a connection structure of the present invention includes: disposing the metal-containing particles or the connecting material between a first member to be connected and a second member to be connected; and a step of heating the metal-containing particles to melt and solidify the tips of the protrusions of the metal part, thereby forming a connecting portion that connects the first connection target member and the second connection target member together from the metal-containing particles or the connecting material.

Fig. 9 is a cross-sectional view schematically showing a connection structure using metal-containing particles according to a first embodiment of the present invention.

The connection structure 51 shown in fig. 9 includes: a first connection object member 52, a second connection object member 53, and a connecting portion 54 connecting the first connection object member 52 and the second connection object member 53 together. The connection portion 54 includes the metal-containing particle 1 and a resin (cured resin or the like). The connection portion 54 is formed of a connection material containing the metal-containing particles 1. The material of the connecting portion 54 is the above-described connecting material. The connecting portion 54 is preferably formed by curing a connecting material. In fig. 9, the tips of the projections 3a of the metal part 3 of the metal-containing particles 1 are melted and then solidified. The connection part 54 includes a joint body of a plurality of metal-containing particles 1. In the connection structure 51, the metal-containing particle 1 and the first connection target member 51 are joined, and the metal-containing particle 1 and the second connection target member 53 are joined.

Instead of the metal-containing particles 1, other metal-containing particles such as the metal-containing particles 1A, the metal-containing particles 1B, the metal-containing particles 1C, the metal-containing particles 1D, the metal-containing particles 1E, the metal-containing particles 1F, and the metal-containing particles 1G may be used.

The first connection target member 52 has a plurality of first electrodes 52a on the surface (upper surface). The second connection target member 53 has a plurality of second electrodes 53a on the front surface (lower surface). The first electrode 52a and the second electrode 53a are electrically connected using 1 or more metal-containing particles 1. Therefore, the first connection target member 52 and the second connection target member 53 are electrically connected by the metal-containing particles 1. In the connection structure 51, the metal-containing particle 1 is joined to the first electrode 52a, and the metal-containing particle 1 is joined to the second electrode 53 a.

The method for producing the connection structure is not particularly limited. As an example of a method for manufacturing the connection structure, there is a method in which the connection material is disposed between the first connection object member and the second connection object member to obtain a laminate, and then the laminate is heated and pressed. The pressure of the pressurization is 9.8X 10⁴～4.9×10⁶Pa or so. The heating temperature is about 120-220 ℃.

Specific examples of the member to be connected include: electronic components such as semiconductor chips, capacitors, and diodes, and electronic components serving as circuit boards such as printed boards, flexible printed boards, glass epoxy boards, and glass boards. The connection object member is preferably an electronic member. The metal-containing particles are preferably used for electrical connection of electrodes in electronic components.

Examples of the electrode provided in the connection target member include metal electrodes such as a gold electrode, a nickel electrode, a tin electrode, an aluminum electrode, a copper electrode, a silver electrode, an SUS electrode, a molybdenum electrode, and a tungsten electrode. When the member to be connected is a flexible printed circuit board, the electrode is preferably a gold electrode, a nickel electrode, a tin electrode, or a copper electrode. When the member to be connected is a glass substrate, the electrode is preferably an aluminum electrode, a copper electrode, a molybdenum electrode, or a tungsten electrode. When the electrode is an aluminum electrode, the electrode may be formed of aluminum alone or an aluminum layer may be laminated on the surface of a metal oxide layer. Examples of the material of the metal oxide layer include indium oxide doped with a metal element having a valence of 3, zinc oxide doped with a metal element having a valence of 3, and the like. Examples of the metal element having a valence of 3 include Sn, Al, and Ga.

Fig. 10 is a cross-sectional view schematically showing a modification of the connection structure using the metal-containing particles according to the first embodiment of the present invention.

The connection structure 61 shown in fig. 10 includes: a first member to be connected 62, a second member to be connected 63, a second member to be connected 64, and a connecting portion 65 and a connecting portion 66 that connect the first member to be connected 62 and the second members to be connected 63 and 64. The connection portions 65 and 66 are formed using a connection material containing the metal-containing particles 1 and other metal-containing particles 67. The material of the connection portions 65 and 66 is the above-described connection material.

The connection portion 65 and the second connection object member 63 are disposed on the first surface (one surface) side of the first connection object member 62. The connection portion 65 connects the first connection target member 62 and the second connection target member 63 together.

The connection portion 66 and the second connection object member 64 are disposed on a second surface (the other surface) side opposite to the first surface of the first connection object member 62. The connection portion 66 connects the first connection target member 62 and the second connection target member 64 together.

The metal-containing particles 1 and the metal-containing particles 67 are arranged between the first connection target member 62, the second connection target member 63, and the second connection target member 64, respectively. In the present embodiment, the particles containing a metal atom and the metal-containing particles 1 in the connection portions 65 and 66 are in a state of a sintered product obtained by sintering. The metal-containing particles 1 are arranged between the first connection target member 62, the second connection target member 63, and the second connection target member 64. The first connection target member 62, the second connection target member 63, and the second connection target member 64 are connected by the metal-containing particles 1.

A heat dissipation groove 68 is disposed on a surface of the second connection target member 63 opposite to the connection portion 65 side. A heat dissipation groove 69 is disposed on the surface of the second member to be connected 64 opposite to the connection portion 66 side. Therefore, the connection structure 61 has a portion in which the heat dissipation groove 68, the second connection object member 63, the connection portion 65, the first connection object member 62, the connection portion 66, the second connection object member 64, and the heat dissipation groove 69 are stacked in this order.

Examples of the first connection target member 62 include power semiconductor elements made of Si, SiC, GaN, or the like used for rectifier diodes, power transistors (power MOSFETs, insulated gate bipolar transistors), thyristors, gate turn-off thyristors, triacs, and the like. In the connection structure 61 including the first connection object member 62, when the connection structure 61 is used, a large amount of heat is likely to be generated in the first connection object member 62. Therefore, it is necessary to efficiently release the heat generated by the first connection target member 62 to the

heat dissipation grooves

68, 69, and the like. Therefore, high heat dissipation and high reliability are required for the connection portions 65 and 66 disposed between the first connection target member 62 and the

heat dissipation grooves

68 and 69.

Examples of the second member to be connected 63 and the second member to be connected 64 include substrates made of ceramics, plastics, or the like.

The connection portions 65 and 66 are formed by heating the connection material to melt and then solidify the tips of the metal-containing particles.

(conduction check Member or conduction Member)

The particle assembly and the connecting material of the present invention can be applied to a conduction test member or a conduction member. One embodiment of the conduction check member is described below. The conduction check member is not limited to the following embodiments. The conduction inspection member and the conduction use member may be sheet-like conduction members.

Fig. 19(a) and 19(b) are a plan view and a cross-sectional view showing an example of a conduction check member. Fig. 19(b) is a sectional view taken along the line a-a in fig. 19 (a).

The conduction testing member 11 shown in fig. 19(a) and 19(b) includes: a base 12 having a through-hole 12a, and a conductive portion 13 disposed in the through-hole 12a of the base 12. The material of the conductive portion 13 contains the metal-containing particles. The conduction check member 11 may be a conduction purpose member.

The base is a member of a substrate as the conduction inspection member. The substrate preferably has an insulating property, and the substrate is preferably formed of an insulating material. Examples of the insulating material include an insulating resin.

The insulating resin constituting the substrate may be any of a thermoplastic resin and a thermosetting resin, for example. Examples of the thermoplastic resin include: polyester resins, polystyrene resins, polyethylene resins, polyamide resins, ABS resins, polycarbonate resins, and the like. Examples of the thermosetting resin include: epoxy resins, polyurethane resins, polyimide resins, polyether ether ketone resins, polyamide imide resins, polyether imide resins, silicone resins, phenol resins, and the like. Examples of the silicone resin include silicone rubber.

When the substrate is formed of an insulating resin, 1 kind of insulating resin alone or 2 or more kinds of insulating resins may be used in combination to form the substrate.

The substrate is, for example, plate-shaped or sheet-shaped. The sheet-like material includes a film. The thickness of the substrate may be appropriately set according to the type of the conduction testing member, and may be, for example, 0.005mm to 50 mm. The size of the substrate in a plan view may be set as appropriate according to a target inspection apparatus.

The substrate can be obtained by molding an insulating material such as the insulating resin described above into a desired shape.

The substrate has a plurality of through holes. The through hole preferably penetrates through the substrate in the thickness direction.

The through-hole of the substrate may be formed in a cylindrical shape, but is not limited to a cylindrical shape, and may be formed in other shapes, for example, a polygonal cylindrical shape. The through hole may be tapered in one direction so that the tip end thereof becomes thinner, or may be formed in a deformed shape.

The size of the through hole, for example, the apparent area of the through hole in a plan view, may be appropriately set, and may be set to a size that can hold the conductive portion, for example. If the through-hole is cylindrical, for example, the diameter of the through-hole is preferably 0.01mm or more, and preferably 10mm or less.

All the through holes of the substrate may have the same shape and the same size, and a part of the through holes of the substrate may have a shape or a size different from those of the other through holes.

The number of the through holes of the substrate may be set within an appropriate range, and may be set as appropriate depending on the target inspection apparatus as long as the number of the through holes is sufficient to perform the continuity inspection. The position of the through hole of the substrate may be set as appropriate according to a target inspection apparatus.

The method for forming the through-hole of the substrate is not particularly limited, and the through-hole may be formed by a known method (for example, laser processing).

The conductive portion in the through hole of the base has conductivity.

Specifically, the conductive part contains particles derived from the metal-containing particles. For example, the conductive portion is formed by accommodating a plurality of metal-containing particles in the through hole. The conductive portion contains an aggregate (particle group) of particles derived from the metal-containing particles.

The material of the conductive portion may contain a material other than the metal-containing particles. For example, the material of the conductive portion may contain a binder in addition to the metal-containing particles. Since the material of the conductive portion contains a binder, the metal-containing particles are more firmly aggregated, and thus particles derived from the metal-containing particles are easily held in the through-holes.

The binder is not particularly limited, and examples thereof include a photocurable resin and a thermosetting resin. The photocurable resin preferably contains a photocurable resin and a photopolymerization initiator. The thermosetting resin preferably contains a thermosetting resin and a thermosetting agent. Examples of the resin include: silicone copolymers, vinyl resins, thermoplastic resins, curable resins, thermoplastic block copolymers, elastomers, and the like. The resin may be used alone in 1 kind, or in combination with 2 or more kinds.

In this case, the conduction test can be performed more reliably by the conduction test member. The conductive portion is preferably housed in the through hole, and is capable of conducting electricity through the conduction inspection member or the conduction member.

In the conductive portion, the particles derived from the metal-containing particles are preferably present in contact with each other continuously from the front surface to the back surface of the conductive portion. In this case, the conductivity of the conductive portion is improved.

A method of housing the conductive portion in the through hole is not particularly limited. For example, a method of applying a material containing the metal-containing particles and a binder to a substrate; or by filling the metal-containing particles in the through-hole and curing the particles under appropriate conditions, a conductive portion can be formed in the through-hole. Thereby, the conductive portion is accommodated in the through hole. The material containing the metal-containing particles and the binder may contain a solvent as needed.

The content of the binder in the material containing the metal-containing particles and the binder is preferably 5 parts by weight or more, more preferably 10 parts by weight or more, preferably 70 parts by weight or less, and more preferably 50 parts by weight or less in terms of solid content, based on 100 parts by weight of the metal-containing particles.

The conduction test member can be used as a probe card. The conduction check member may include other components to the extent that the effects of the present invention are not impaired.

Fig. 20(a) to 20(c) are diagrams schematically showing a mode of inspecting electrical characteristics of an electronic circuit device by a conduction inspection member.

In fig. 20 a to 20 c, the electronic circuit device is a BGA substrate 31 (ball grid array substrate). The BGA substrate 31 has a structure in which connection pads are arranged in a grid pattern on a multilayer substrate 31A, and solder balls 31B are arranged on the respective pads. In fig. 20(a) to 20(c), the conduction test member 21 is a probe card. The conduction check member 21 has a plurality of through holes 22a formed in the base 22, and the conductive portions 23 are accommodated in the through holes 22 a. As shown in fig. 20(a), the BGA substrate 31 and the conduction testing member 21 are prepared, and as shown in fig. 20(b), the BGA substrate 31 and the conduction testing member 21 are brought into contact and compressed. At this time, solder ball 31B contacts conductive portion 23 in through hole 22 a. In this state, as shown in fig. 20(c), the ammeter 32 is connected to perform a conduction check, and whether or not the BGA substrate 31 is acceptable can be determined.

The present invention will be described in detail below with reference to examples and comparative examples. The present invention is not limited to the following examples.

(example 1)

As the base particles A, divinylbenzene copolymer resin particles (Micropearl SP-203 manufactured by Water-accumulation chemical Co., Ltd.) having a particle diameter of 3.0 μm were prepared.

The base particles a were taken out by dispersing 10 parts by weight of the base particles a in 100 parts by weight of an alkali solution containing 5% by weight of a palladium catalyst solution using an ultrasonic disperser and then filtering the solution. Next, 100 parts by weight of a1 wt% dimethylamine borane solution was added to the base particles a to activate the surfaces of the base particles a. The surface-activated substrate particles a were sufficiently washed with water, and then, 500 parts by weight of distilled water was added thereto and dispersed, thereby obtaining a suspension (a).

Then, 1 part by weight of a metallic nickel particle slurry ("2020 SUS", manufactured by Mitsui Metal corporation, having an average particle diameter of 150nm) was added to the suspension (A) over 3 minutes to obtain a suspension (B) containing the base material particles A to which the core material was attached.

The suspension (B) was added to a solution containing 20g/L copper sulfate and 30g/L ethylenediaminetetraacetic acid to obtain a particle mixture (C).

Further, as an electroless copper plating solution, a copper plating solution (D) was prepared by adjusting a mixture solution containing 250g/L copper sulfate, 150g/L ethylenediaminetetraacetic acid, 100g/L sodium gluconate, and 50g/L formaldehyde to pH10.5 with ammonia.

Further, as an electroless silver plating solution, a silver plating solution (E) was prepared by adjusting a mixed solution containing 30g/L silver nitrate, 100g/L succinimide, and 20g/L formaldehyde to pH8.0 with ammonia water.

A plating solution (F) for forming a bump, which contained 100g/L of dimethylamine borane and 0.5g/L of sodium hydroxide, was prepared (pH 10.0).

The copper plating solution (D) was slowly dropped into the particle mixture (C) adjusted to a dispersion state of 55 ℃ to carry out electroless copper plating. The copper plating solution (D) was added dropwise at a rate of 30 mL/min for 30 minutes to carry out electroless copper plating. As described above, a particle mixture (G) containing particles having a metal portion, in which a copper metal portion is disposed on the surface of a resin particle and the copper metal portion has a convex portion on the surface, is obtained.

Thereafter, the particle mixture (G) is filtered to remove particles, and the particles are washed with water to obtain particles having a metal portion in which a copper metal portion having a convex portion on the surface is disposed on the surface of the substrate particle a. After the particles were sufficiently washed with water, 500 parts by weight of distilled water was added thereto and dispersed, thereby obtaining a particle mixed solution (H).

Next, the silver plating solution (E) was slowly dropped into the particle mixed solution (H) adjusted to a dispersion state of 60 ℃, and electroless silver plating was performed. Electroless silver plating was performed by using the silver plating solution (E) at a dropping rate of 10 mL/min for a dropping time of 30 minutes. Thereafter, the plating solution (F) for forming a protrusion is slowly dropped to form a protrusion. The projection was formed at a dropping rate of 1 mL/min and a dropping time of 10 minutes for the projection-forming plating solution (F). During the dropping of the plating solution (F) for forming the projection, silver plating is performed while dispersing the generated silver projection nuclei by ultrasonic agitation (projection forming step). Then, particles were taken out by filtration, washed with water, and dried to obtain metal-containing particles having a metal part in which copper and silver metal parts (thickness of the entire metal part in the portion where the convex part is not present: 0.1 μm) are arranged on the surface of the base particle A, the metal part having a convex part on the surface, and a plurality of protrusions on the surface of the convex part.

(example 2)

Metal-containing particles were obtained in the same manner as in example 1, except that the metallic nickel particle slurry was changed to alumina particle slurry (average particle diameter 150 nm).

(example 3)

The suspension (A) obtained in example 1 was put into a solution containing 40ppm of nickel sulfate, 2g/L of trisodium citrate, and 10g/L of aqueous ammonia to obtain a particle mixture (B).

As a plating solution for forming the needle-like protrusions, a plating solution (C) for forming the needle-like protrusions was prepared as an electroless copper-nickel-phosphorus alloy plating solution, which was obtained by adjusting a mixed solution containing 100g/L copper sulfate, 10g/L nickel sulfate, 100g/L sodium hypophosphite, 70g/L trisodium citrate, 10g/L boric acid, and 5mg/L polyethylene glycol 1000 (molecular weight: 1000) as a nonionic surfactant to pH10.0 with ammonia water.

Further, as an electroless silver plating solution, a silver plating solution (D) was prepared by adjusting a mixed solution of 30g/L silver nitrate, 100g/L succinimide, and 20g/L formaldehyde to pH8.0 with ammonia water.

A plating solution (E) for forming a bump, which contained 100g/L of dimethylamine borane and 0.5g/L of sodium hydroxide, was prepared (pH 10.0).

The needle-like projection-forming plating solution (C) is slowly dropped into the particle mixed solution (B) adjusted to a dispersion state of 70 ℃. The needle-like projection-forming plating solution (C) was added dropwise at a rate of 40 mL/min for 60 minutes, and electroless copper-nickel-phosphorus alloy plating was performed (needle-like projection-forming and copper-nickel-phosphorus alloy plating step). Then, the particles are removed by filtration to obtain particles (F) having a metal portion in which a copper-nickel-phosphorus alloy metal portion having a convex portion on the surface is disposed on the surface of the base particles a. The particles (F) were added to 500 parts by weight of distilled water and dispersed, thereby obtaining a suspension (G).

Thereafter, the suspension (G) is filtered to remove particles having a copper-nickel-phosphorus alloy metal portion disposed on the surface of the base particle a, and the particles are washed with water to obtain particles having a metal portion having a needle-like convex portion on the surface. The particles were sufficiently washed with water, and then 500 parts by weight of distilled water was added thereto and dispersed, thereby obtaining a particle mixed solution (H).

Next, the silver plating solution (D) was slowly dropped into the particle mixed solution (H) adjusted to a dispersion state of 60 ℃, and electroless silver plating was performed. Electroless silver plating was performed with the dropping speed of the silver plating solution (D) at 10 mL/min for 30 minutes. Thereafter, the plating solution (E) for forming a protrusion is slowly dropped to form a protrusion. The plating solution (E) for forming a protrusion was added at a rate of 1 mL/min for 10 minutes to form a protrusion. During the dropping of the plating solution (E) for forming the protrusions, silver plating is performed while dispersing the generated silver protrusion nuclei by ultrasonic agitation (protrusion forming step). Then, particles having a copper-nickel-phosphorus alloy and a silver metal portion (the thickness of the entire metal portion in the portion where the convex portion is not present: 0.1 μm) having a plurality of needle-like convex portions on the surface and a plurality of protrusions on the surface of the convex portion were disposed on the surface of the base particle A were taken out by filtration, washed with water, and dried to obtain metal-containing particles.

(example 4)

The suspension (A) obtained in example 1 was put into a solution containing 80g/L of nickel sulfate, 10ppm of thallium nitrate, and 5ppm of bismuth nitrate to obtain a particle mixture (B).

As the plating solution for forming needle-like projections, a plating solution (C) for forming needle-like projections was prepared as an electroless high-purity nickel plating solution, which was obtained by adjusting a mixed solution containing 100g/L of nickel chloride, 100g/L of hydrazine monohydrate, 50g/L of trisodium citrate, and 20mg/L of polyethylene glycol 1000 (molecular weight: 1000) to pH9.0 with sodium hydroxide.

Further, as an electroless silver plating solution, a silver plating solution (D) was prepared, and obtained by adjusting a mixed solution containing 30g/L silver nitrate, 100g/L succinimide, and 20g/L formaldehyde to pH8.0 with ammonia water.

The needle-like projection-forming plating solution (C) is slowly dropped into the particle mixed solution (B) adjusted to a dispersion state of 60 ℃ to form needle-like projections. The needle-like projection-forming plating solution (C) was added dropwise at a rate of 20 mL/min for 50 minutes, and electroless high-purity nickel plating was performed (needle-like projection formation and copper-nickel-phosphorus alloy plating step). Thereafter, particles were taken out by filtration to obtain particles (F) having a metal portion with a high-purity nickel metal portion disposed on the surface of the base particle a, and a convex portion on the surface of the metal portion. The particles (F) were added to 500 parts by weight of distilled water and dispersed, thereby obtaining a suspension (G).

Thereafter, the suspension (G) was filtered to remove particles having a metal portion with a needle-like projection on the surface, the particles having a high-purity nickel metal portion disposed on the surface of the substrate particle a, and the particles were washed with water. After the particles were sufficiently washed with water, 500 parts by weight of distilled water was added thereto and dispersed, thereby obtaining a particle mixed solution (H).

Next, the silver plating solution (D) was slowly dropped into the particle mixed solution (H) adjusted to a dispersion state of 60 ℃, and electroless silver plating was performed. Electroless silver plating was performed with the dropping speed of the silver plating solution (D) at 10 mL/min for 30 minutes. Thereafter, the plating solution (E) for forming a protrusion is slowly dropped to form a protrusion. The plating solution (E) for forming a protrusion was added at a rate of 1 mL/min for 10 minutes to form a protrusion. During the dropping of the plating solution (E) for forming the protrusions, silver plating is performed while dispersing the generated silver protrusion nuclei by ultrasonic agitation (protrusion forming step). Then, particles having a metal portion with a needle-like convex portion on the surface and a plurality of protrusions on the surface of the convex portion are taken out by filtration to obtain a particle mixture (I) having a metal portion with a high-purity nickel and silver metal portion disposed on the surface of the base particle a.

Thereafter, the particle mixture (I) was filtered to take out particles, and the particles were washed with water and dried to obtain metal-containing particles in which high-purity nickel and silver metal portions (thickness of the entire metal portion in the portion where no convex portion exists: 0.1 μm) having a plurality of needle-like convex portions on the surface and a plurality of protrusions on the surface of the convex portion were disposed on the surface of the base material particle a.

(example 5)

The suspension (A) obtained in example 1 was put into a solution containing 500ppm of silver nitrate, 10g/L of succinimide and 10g/L of ammonia water to obtain a particle mixture (B).

As an electroless silver plating solution, a silver plating solution (C) was prepared by adjusting a mixture solution containing 30g/L silver nitrate, 100g/L succinimide, and 20g/L formaldehyde to a pH of 8 with ammonia water.

A plating solution (D) (pH10.0) for forming a bump, containing 100g/L of dimethylamine borane and 0.5g/L of sodium hydroxide, was prepared.

The electroless silver plating solution (C) was slowly dropped into the particle mixture (B) adjusted to a dispersion state of 60 ℃, thereby forming needle-like protrusions. Electroless silver plating was performed with the electroless silver plating solution (C) being dropped at a rate of 10 mL/min for 30 minutes (silver plating step). Thereafter, the plating solution (D) for forming a protrusion is slowly dropped to form a protrusion. The plating solution (D) for forming a protrusion was added at a rate of 1 mL/min for 10 minutes to form a protrusion. During the dropping of the plating solution (D) for forming the protrusions, silver plating is performed while stirring and dispersing the generated silver protrusion nuclei by ultrasonic waves (protrusion forming step). Thereafter, particles were taken out by filtration, washed with water, and dried to obtain metal-containing particles in which silver metal portions (thickness of the entire metal portion without protruding portions: 0.1 μm) having a plurality of protrusions on the surface thereof were arranged on the surface of the base particles a.

(example 6)

The suspension (A) obtained in example 1 was put into a solution containing 500ppm of silver potassium cyanide, 10g/L of potassium cyanide, and 10g/L of potassium hydroxide to obtain a particle mixture (B).

As a plating solution for forming the needle-like protrusions, a silver plating solution (C) was prepared by adjusting a mixture solution containing 80g/L of silver potassium cyanide, 10g/L of potassium cyanide, 20mg/L of polyethylene glycol 1000 (molecular weight: 1000), 50ppm of thiourea, and 100g/L of hydrazine monohydrate to pH7.5 with potassium hydroxide.

The electroless silver plating solution (C) was slowly dropped into the particle mixture (B) adjusted to a dispersion state of 80 ℃ to form needle-like protrusions. Electroless silver plating (needle-like projection formation and silver plating step) was performed at a dropping rate of 10 mL/min and a dropping time of 60 minutes. Thereafter, the particles were taken out by filtration, washed with water and dried to obtain metal-containing particles in which silver metal portions (the thickness of the entire metal portion without projections: 0.1 μm) having a plurality of needle-like projections formed on the surface thereof were arranged on the surface of the resin particles.

(example 7)

Further, as an electroless silver plating solution, a silver plating solution (D) was prepared by adjusting a mixed solution containing 30g/L silver nitrate, 100g/L succinimide, and 20g/L formaldehyde to pH8.0 with ammonia water.

The electroless silver plating solution (C) was slowly dropped into the particle mixture (B) adjusted to a dispersion state of 80 ℃ to form needle-like protrusions. Electroless silver plating (needle-like projection formation and silver plating step) was performed at a dropping rate of 10 mL/min and a dropping time of 45 minutes.

Thereafter, particles were taken out by filtration to obtain particles (F) having a metal portion with a needle-like projection on the surface, the particles (F) having a silver metal portion disposed on the surface of the base particle a. The particles (F) were added to 500 parts by weight of distilled water and dispersed to obtain a particle mixed solution (G).

Next, the silver plating solution (D) was slowly dropped into the particle mixed solution (G) adjusted to a dispersion state of 60 ℃, and electroless silver plating was performed. Electroless silver plating was performed with the dropping speed of the silver plating solution (D) at 10 mL/min for 30 minutes. Thereafter, the plating solution (E) for forming a protrusion is slowly dropped to form a protrusion. The plating solution (E) for forming a protrusion was added at a rate of 1 mL/min for 10 minutes to form a protrusion. During the dropping of the plating solution (E) for forming the protrusions, silver plating is performed while stirring and dispersing the generated silver protrusion nuclei by ultrasonic waves (protrusion forming step). Thereafter, particles having a metal portion with a plurality of needle-like convex portions on the surface and a plurality of protrusions on the surface of the convex portion were obtained by taking out the particles by filtration, washing with water, and drying the particles, thereby obtaining metal-containing particles having a metal portion with a silver metal portion (thickness of the entire metal portion in a portion where the convex portion is not present: 0.1 μm) arranged on the surface of the base particle A.

(example 8)

The suspension (B) obtained in example 1 was put into a solution containing 50g/L of nickel sulfate, 30ppm of thallium nitrate, and 20ppm of bismuth nitrate to obtain a particle mixture (C).

As the electroless nickel-tungsten-boron alloy plating solution, an electroless nickel-tungsten-boron alloy plating solution (D) was prepared by adjusting a mixed solution containing 100g/L of nickel sulfate, 5g/L of sodium tungstate, 30g/L of dimethylamine borane, 10ppm of bismuth nitrate, and 30g/L of trisodium citrate to pH6 with sodium hydroxide.

Further, as an electroless silver plating solution, a silver plating solution (E) was prepared by adjusting a mixed solution of 30g/L silver nitrate, 100g/L succinimide, and 20g/L formaldehyde to pH8.0 with ammonia water.

The electroless nickel-tungsten-boron alloy plating solution (D) is slowly dropped into the particle mixed solution (C) adjusted to a dispersion state of 60 ℃ to perform electroless nickel-tungsten-boron alloy plating. Electroless nickel-tungsten-boron alloy plating was performed with the electroless nickel-tungsten-boron alloy plating solution (D) being dropped at a rate of 15 mL/min for 60 minutes. As described above, a particle mixture (G) containing particles having a nickel-tungsten-boron alloy metal portion disposed on the surface of the base particle a and having a convex portion on the surface is obtained.

Thereafter, the particle mixture (G) is filtered to take out particles having a metal part with a convex part on the surface, and the particles are washed with water to obtain particles having a metal part with a nickel-tungsten-boron alloy metal layer disposed on the surface of the substrate particles a. The particles were sufficiently washed with water, and then 500 parts by weight of distilled water was added thereto and dispersed, thereby obtaining a particle mixed solution (H).

Next, the silver plating solution (E) was slowly dropped into the particle mixed solution (H) adjusted to a dispersion state of 60 ℃, and electroless silver plating was performed. The electroless silver plating was carried out at a dropping rate of 10 mL/min and a dropping time of 30 minutes for the silver plating solution (E). Thereafter, the plating solution (F) for forming a protrusion is slowly dropped to form a protrusion. The projection was formed at a dropping rate of 1 mL/min and a dropping time of 10 minutes for the projection-forming plating solution (F). During the dropping of the plating solution (F) for forming the protrusions, silver plating is performed while stirring and dispersing the generated silver protrusion nuclei by ultrasonic waves (protrusion forming step). Thereafter, particles having a metal portion with a plurality of convex portions on the surface and a plurality of protrusions on the surface of the convex portion were obtained by taking out the particles by filtration, washing with water, and drying the particles, thereby obtaining metal-containing particles having a metal portion with a nickel-tungsten-boron alloy and a silver metal portion (thickness of the entire metal portion in a portion where the convex portion is not present: 0.1 μm) on the surface of the base particles a.

(example 9)

As the electroless nickel-tungsten-boron alloy plating solution, an electroless nickel-tungsten-boron alloy plating solution (D) was prepared by adjusting a mixed solution containing 100g/L of nickel sulfate, 2g/L of sodium tungstate, 30g/L of dimethylamine borane, 10ppm of bismuth nitrate, and 30g/L of trisodium citrate to pH6 with sodium hydroxide.

Further, as an electroless gold plating solution, a gold plating solution (E) was prepared by adjusting a mixture solution containing 30g/L of potassium gold cyanide, 2g/L of potassium cyanide, 30g/L of trisodium citrate, 15g/L of ethylenediaminetetraacetic acid, 10g/L of potassium hydroxide, and 20g/L of dimethylamine borane to pH8.0 with potassium hydroxide.

A plating solution (F) for forming protrusions (pH10.0) containing 30g/L of sodium borohydride and 0.5g/L of sodium hydroxide was prepared.

The electroless nickel-tungsten-boron alloy plating solution (D) is slowly dropped into the particle mixed solution (C) adjusted to a dispersion state of 60 ℃ to perform electroless nickel-tungsten-boron alloy plating. Electroless nickel-tungsten-boron alloy plating was performed with the electroless nickel-tungsten-boron alloy plating solution (D) being dropped at a rate of 15 mL/min for 60 minutes. As described above, particles (G) having a metal portion with a convex portion on the surface were obtained, the particles (G) having a nickel-tungsten-boron alloy metal portion disposed on the surface of the base particles a.

Thereafter, the suspension (G) is filtered to take out particles having a nickel-tungsten-boron alloy metal portion disposed on the surface of the base particle a, and the particles are washed with water to obtain particles having a metal portion having a convex portion on the surface. After the particles were sufficiently washed with water, 500 parts by weight of distilled water was added thereto and dispersed, thereby obtaining a particle mixed solution (H).

Then, the electroless gold plating solution (E) was slowly dropped into the particle mixture (H) adjusted to a dispersion state of 60 ℃, and electroless gold plating was performed. Electroless gold plating was performed at a dropping rate of 10 mL/min and a dropping time of 30 minutes for electroless gold plating. Thereafter, the plating solution (F) for forming a protrusion is slowly dropped to form a protrusion. The plating solution (F) for forming a protrusion was added at a rate of 1 mL/min for 5 minutes to form a protrusion. During the dropping of the plating solution (F) for forming a bump, gold plating is performed while stirring and dispersing the generated gold bump nuclei by ultrasonic waves (bump forming step). Thereafter, particles having a metal portion with a plurality of convex portions on the surface and a plurality of protrusions on the surface of the convex portion were obtained by taking out the particles by filtration, washing with water, and drying the particles, thereby obtaining metal-containing particles having a metal portion with a nickel-tungsten-boron alloy and a gold metal portion (thickness of the entire metal portion in a portion where no convex portion exists: 0.1 μm) disposed on the surface of the base particles a.

(example 10)

The suspension (B) obtained in example 1 was put into a solution containing 20g/L copper sulfate and 30g/L ethylenediaminetetraacetic acid to obtain a particle mixture (C).

Further, as an electroless tin plating solution, a tin plating solution (E) was prepared by adjusting a mixed solution containing 20g/L of tin chloride, 50g/L of nitrosotriacetic acid, 2g/L of thiourea, 1g/L of thiomalic acid, 7.5g/L of ethylenediaminetetraacetic acid, and 15g/L of titanium trichloride to pH7.0 with sulfuric acid.

Further, a plating solution (F) for forming a bump, which contained 100g/L of dimethylamine borane, was prepared (pH 7.0).

The copper plating solution (D) was slowly dropped into the particle mixture (C) adjusted to a dispersion state of 55 ℃ to carry out electroless copper plating. The copper plating solution (D) was added dropwise at a rate of 30 mL/min for 30 minutes to carry out electroless copper plating. Thereafter, particles are taken out by filtration, and thus a particle mixture (G) containing particles having a metal portion with a convex portion on the surface, in which the copper metal portion is arranged on the surface of the base particle a, is obtained.

Thereafter, the particle mixture (G) is filtered to take out particles having a metal portion with a convex portion on the surface, and the particles are washed with water to obtain particles having a metal portion in which the copper portion is disposed on the surface of the substrate particle a. After the particles were sufficiently washed with water, 500 parts by weight of distilled water was added thereto and dispersed, thereby obtaining a particle mixed solution (H).

Subsequently, the tin plating solution (E) was slowly dropped into the particle mixed solution (H) adjusted to a dispersion state of 60 ℃, and electroless tin plating was performed. Electroless tin plating was performed with the tin plating solution (E) added at a rate of 10 mL/min for 30 minutes. Thereafter, the plating solution (F) for forming a protrusion is slowly dropped to form a protrusion. The projection was formed at a dropping rate of 1 mL/min and a dropping time of 10 minutes for the projection-forming plating solution (F). During the dropping of the plating solution (F) for forming the bump, the tin plating is performed while stirring and dispersing the generated tin bump nuclei by ultrasonic waves (bump forming step). Thereafter, particles having a plurality of projections on the surface and a plurality of protrusions on the surface of the projections were obtained by taking out the particles by filtration, washing with water, and drying, thereby obtaining metal-containing particles having metal portions in which copper and tin metal portions (thickness of the entire metal portion in the portion where no projections are present: 0.1 μm) were disposed on the surface of the base particle A.

(example 11)

(1) Preparation of polysiloxane oligomers

1 part by weight of 1, 3-divinyltetramethyldisiloxane and 20 parts by weight of a 0.5% by weight aqueous solution of p-toluenesulfonic acid were placed in a 100ml separable flask placed in a warm bath. After stirring at 40 ℃ for 1 hour, 0.05 part by weight of sodium hydrogencarbonate was added. Then, 10 parts by weight of dimethoxymethylphenylsilane, 49 parts by weight of dimethyldimethoxysilane, 0.6 part by weight of trimethylmethoxysilane, and 3.6 parts by weight of methyltrimethoxysilane were added thereto, and the mixture was stirred for 1 hour. Thereafter, 1.9 parts by weight of a 10% by weight aqueous solution of potassium hydroxide was added, the temperature was raised to 85 ℃ and the mixture was stirred for 10 hours while reducing the pressure with an aspirator to carry out a reaction. After the reaction was completed, the reaction mixture was returned to normal pressure, cooled to 40 ℃ and then added with 0.2 part by weight of acetic acid, and the mixture was allowed to stand in a separatory funnel for 12 hours or longer. The lower layer after the two layers were separated was taken out and purified by an evaporator, whereby a polysiloxane oligomer was obtained.

(2) Preparation of Silicone particulate Material (containing organic Polymer)

A solution A was prepared in which 0.5 part by weight of t-butyl-2-ethyl peroxyhexanoate (polymerization initiator, "Perbutyl O" manufactured by Nichigan Co., Ltd.) was dissolved in 30 parts by weight of the obtained polysiloxane oligomer. In addition, 150 parts by weight of ion-exchanged water was mixed with 0.8 part by weight of a 40 wt% aqueous solution (emulsifier) of triethanolamine lauryl sulfate and 80 parts by weight of a 5 wt% aqueous solution of polyvinyl alcohol ("GOHSENOL GH-20" manufactured by Nippon synthetic chemical Co., Ltd., having a polymerization degree of about 2000 and a saponification degree of 86.5 to 89 mol "). The solution a was placed in a separable flask provided in a warm bath, and then the aqueous solution B was added thereto. Thereafter, emulsification was performed by using Shirasu Pore Glass (SPG) membrane (average pore diameter about 1 μm). Thereafter, the temperature was raised to 85 ℃ to carry out polymerization for 9 hours. The total amount of the particles after polymerization was washed with water by centrifugation and freeze-dried. After drying, the particles were pulverized by a ball mill until the aggregate became a target ratio (average 2-order particle diameter/average 1-order particle diameter), to obtain polysiloxane particles (base material particles B) having a particle diameter of 3.0 μm.

The base particle a was changed to the base particle B, and a metal portion was formed in the same manner as in example 1 to obtain a metal-containing particle.

(example 12)

Polysiloxane particles (base particles C) having a particle diameter of 3.0 μm were obtained by using both-terminal acrylic silicone oil ("X-22-2445" manufactured by shin Etsu chemical Co., Ltd.) in place of the polysiloxane oligomer.

The base particle a was changed to the base particle C, and a metal portion was formed in the same manner as in example 1 to obtain a metal-containing particle.

(example 13)

Pure copper particles ("HXR-Cu" manufactured by Japan atom Mize processing Co., Ltd., particle size 2.5 μm) were prepared as the base particles D.

The base particles a were changed to the base particles D, and metal portions were formed in the same manner as in example 1 to obtain metal-containing particles.

(example 14)

Pure silver particles (particle size 2.5 μm) were prepared as the base particles E.

The base particles a were changed to the base particles E, and metal portions were formed in the same manner as in example 1 to obtain metal-containing particles.

(example 15)

Base particles F having a particle diameter of 2.0 μm, which is different from that of the base particles A, were prepared.

The base particles a were changed to the base particles F, and metal portions were formed in the same manner as in example 1 to obtain metal-containing particles.

(example 16)

Base material particles G having a particle diameter of 10.0 μm, which was different from that of the base material particles A, were prepared.

The base particles a were changed to the base particles G, and metal portions were formed in the same manner as in example 1 to obtain metal-containing particles.

(example 17)

Base particles H having a particle diameter of 50.0 μm, which is different from that of the base particles A, were prepared.

The base particles a were changed to the base particles H, and metal portions were formed in the same manner as in example 1 to obtain metal-containing particles.

(example 18)

A monomer composition containing 100mmol of methyl methacrylate, 1mmol of N, N, N-trimethyl-N-2-methacryloyloxyethyl ammonium chloride and 1mmol of 2, 2' -azobis (2-amidinopropane) dihydrochloride was weighed in a 1000mL separable flask equipped with a four-neck separable cap, a stirring blade, a three-way stopcock, a cooling tube and a temperature probe so that the solid content rate became 5% by weight in ion-exchanged water, and then, polymerization was carried out at 70 ℃ for 24 hours under a nitrogen atmosphere with stirring at 200 rpm. After the reaction, the mixture was freeze-dried to obtain insulating particles having ammonium groups on the surface, an average particle diameter of 220nm and a CV value of 10%.

Insulating particles were dispersed in ion-exchanged water under ultrasonic irradiation to obtain a 10 wt% aqueous dispersion of insulating particles.

10g of the metal-containing particles obtained in example 1 were dispersed in 500mL of ion-exchanged water, and 4g of an aqueous dispersion of insulating particles was added thereto, followed by stirring at room temperature for 6 hours. After filtration through a 3 μm mesh filter, the resultant was further washed with methanol and dried to obtain metal-containing particles having insulating particles adhered thereto.

As a result of observation with a Scanning Electron Microscope (SEM), only a coating layer of 1 layer of the insulating particles was formed on the surface of the metal-containing particles. The coating ratio of the coated area of the insulating particles to the area 2.5 μm from the center of the metal-containing particles (i.e., the projected area of the particle diameter of the insulating particles) was calculated by image analysis, and as a result, the coating ratio was 30%.

(example 19)

As the electroless nickel-phosphorus alloy plating solution, an electroless nickel-phosphorus alloy plating solution (D) was prepared by adjusting a mixed solution containing 100g/L nickel sulfate, 30g/L sodium hypophosphite, 10ppm bismuth nitrate, and 30g/L trisodium citrate to a pH of 6 with sodium hydroxide.

A plating solution (F) for forming protrusions (pH12.0) containing 130g/L of sodium hypophosphite and 0.5g/L of sodium hydroxide was prepared.

The electroless nickel-phosphorus alloy plating solution (D) was slowly dropped into the particle mixture (C) adjusted to a dispersion state of 65 ℃ to perform electroless nickel-phosphorus alloy plating. Electroless nickel-phosphorus alloy plating was performed at a dropping rate of 15 mL/min and a dropping time of 60 minutes for the electroless nickel-phosphorus alloy plating solution (D). As described above, a particle mixture (G) containing particles having a nickel-phosphorus alloy metal portion disposed on the surface of the base particle a and having a convex portion on the surface was obtained.

Thereafter, the particle mixture (G) is filtered to take out particles having a metal part with a convex part on the surface, and the particles are washed with water to obtain particles having a metal part with a nickel-phosphorus alloy metal layer disposed on the surface of the substrate particles a. After the particles were sufficiently washed with water, 500 parts by weight of distilled water was added thereto and dispersed, thereby obtaining a particle mixed solution (H).

Next, the silver plating solution (E) was slowly dropped into the particle mixed solution (H) adjusted to a dispersion state of 60 ℃, and electroless silver plating was performed. The electroless silver plating was carried out at a dropping rate of 10 mL/min and a dropping time of 30 minutes for the silver plating solution (E). Thereafter, the plating solution (F) for forming a protrusion is slowly dropped to form a protrusion. The projection was formed at a dropping rate of 1 mL/min and a dropping time of 10 minutes for the projection-forming plating solution (F). During the dropping of the plating solution (F) for forming the protrusions, silver plating is performed while stirring and dispersing the generated silver protrusion nuclei by ultrasonic waves (protrusion forming step). Then, particles having a metal part with a plurality of convex parts on the surface and a plurality of protrusions on the surface of the convex part were obtained by taking out the particles by filtration, washing with water, and drying, thereby obtaining metal-containing particles having a metal part with a nickel-phosphorus alloy and a silver metal part (thickness of the entire metal part in the portion where the convex part is not present: 0.1 μm) arranged on the surface of the base particle a.

(example 20)

The metal-containing particles obtained in example 1 were subjected to an anti-sulfurization treatment using "NEWDAINSILVER" manufactured by Daihu chemical Co., Ltd as an anti-silver-discoloration agent.

The metal-containing particles having the anti-vulcanization film formed thereon were obtained by dispersing 10 parts by weight of the metal-containing particles obtained in example 1 in 100 parts by weight of an isopropyl alcohol solution containing NEWDAINSILVER 10% by weight using an ultrasonic disperser and then filtering the solution.

(example 21)

The metal-containing particles obtained in example 1 were subjected to an anti-vulcanization treatment using a 2-mercaptobenzimidazole solution as an anti-silver vulcanizing agent.

The metal-containing particles obtained in example 1 were dispersed in 10 parts by weight in 100 parts by weight of an isopropyl alcohol solution containing 0.5% by weight of 2-mercaptobenzimidazole using an ultrasonic disperser, and the solution was filtered to obtain metal-containing particles having an anti-vulcanization film formed thereon.

Comparative example 1

The base particles a were taken out by dispersing 10 parts by weight of the base particles a in 100 parts by weight of an alkali solution containing 5% by weight of a palladium catalyst solution using an ultrasonic disperser and then filtering the solution. Next, 100 parts by weight of a1 wt% dimethylamine borane solution was added to the base particles a to activate the surfaces of the base particles a. After the substrate particles a whose surfaces were activated were sufficiently washed with water, they were dispersed in 500 parts by weight of distilled water to obtain a dispersion (a).

Then, 1g of a metallic nickel particle slurry ("2020 SUS", manufactured by Mitsui Metal corporation, having an average particle diameter of 150nm) was added to the dispersion (A) over 3 minutes to obtain a suspension (B) containing the base material particles A to which the core material had adhered.

The suspension (B) was put into a solution containing 50g/L of nickel sulfate, 30ppm of thallium nitrate, and 20ppm of bismuth nitrate to obtain a particle mixture (C).

Further, a nickel plating solution (D) (pH6.5) containing 200g/L of nickel sulfate, 85g/L of sodium hypophosphite, 30g/L of sodium citrate, 50ppm of thallium nitrate, and 20ppm of bismuth nitrate was prepared.

The nickel plating solution (D) was slowly dropped into the particle mixture (C) adjusted to a dispersion state of 50 ℃ to perform electroless nickel plating. Electroless nickel plating was performed with the dropping speed of the nickel plating solution (D) being 25 mL/min and the dropping time being 60 minutes (Ni plating step). Thereafter, particles having a nickel-phosphorus alloy metal portion disposed on the surface of the base particle A and having protrusions on the surface thereof were taken out by filtration, washed with water, and dried to obtain a metal-containing particle alloy (thickness of the entire metal portion in the portion without protrusions: 0.1 μm) having metal portions disposed on the surface of the base particle A.

Comparative example 2

In 100 parts by weight of an alkali solution containing 5% by weight of a palladium catalyst solution, 10 parts by weight of the base particles a were dispersed using an ultrasonic disperser, and then the solution was filtered, thereby taking out the base particles a. Next, the base particles a were added to 100 parts by weight of a1 wt% solution of dimethylamine borane, thereby activating the surfaces of the base particles a. The substrate particles a whose surfaces were activated were sufficiently washed with water, and then, 500 parts by weight of distilled water was added thereto and dispersed, thereby obtaining a suspension (a).

The suspension (A) was put into a solution containing 50g/L of nickel sulfate, 30ppm of thallium nitrate, and 20ppm of bismuth nitrate to obtain a particle mixture (B).

A plating solution (C) for forming protrusions (pH11.0) containing 300g/L sodium hypophosphite and 10g/L sodium hydroxide was prepared.

The projection is formed by slowly dropping the plating solution (C) for forming projections into the particle mixed solution (B) adjusted to a dispersion state of 50 ℃. The plating solution (C) for forming a protrusion was added at a dropping rate of 20 mL/min for 5 minutes to form a protrusion. During the dropping of the plating solution (C) for forming the protrusions, nickel plating is performed while stirring and dispersing the generated Ni protrusion nuclei by ultrasonic waves (protrusion forming step). As described above, a mixed solution (E) of Ni protruding nuclei and particles in a dispersed state was obtained.

Thereafter, the nickel plating solution (D) is slowly dropped into the dispersed Ni protruding nuclei and particle mixed solution (E) to perform electroless nickel plating. Electroless nickel plating was carried out with the dropping speed of the nickel plating solution (D) being 25 mL/min and the dropping time being 60 minutes. During the dropping of the nickel plating solution (D), nickel plating is performed while stirring and dispersing the generated Ni protruding nuclei by ultrasonic waves (Ni plating step). Thereafter, the particles were taken out by filtration, washed with water and dried to obtain metal-containing particles (thickness of the entire metal part without projections: 0.1 μm) having metal parts with projections on the surface of the base particles A and nickel-phosphorus alloy metal parts disposed on the surface of the metal parts.

(evaluation)

(1) Measurement of height of convex portion and protrusion

The obtained metal-containing particles were added to "Technovit 4000" manufactured by Kulzer, and dispersed so that the content thereof was 30% by weight, thereby producing embedded resins for metal-containing particle inspection. The cross section of the metal-containing particles was cut out by an ion milling device ("IM 4000" manufactured by hitachi high-tech corporation) so as to be dispersed in the vicinity of the center of the metal-containing particles in the inspection resin.

Then, using a field emission transmission electron microscope (FE-TEM) (JEM-ARM 200F, manufactured by japan electronics corporation), the image magnification was set to 5 ten thousand times, 20 metal-containing particles were randomly selected, and the convex portions and protrusions of each metal-containing particle were observed. The heights of the convex portions and protrusions in the obtained metal-containing particles were measured, and the average height of the convex portions and protrusions was obtained by arithmetic averaging.

(2) Determination of the mean diameter of the base of the protrusions

The obtained metal-containing particles were dispersed in "Technovit 4000" manufactured by Kulzer, and the content thereof was adjusted to 30% by weight, thereby preparing a metal-containing embedded resin for particle inspection. The cross section of the metal-containing particles was cut out by an ion milling device ("IM 4000" manufactured by hitachi high-tech corporation) so as to be dispersed in the vicinity of the center of the metal-containing particles in the inspection resin.

Then, using a field emission transmission electron microscope (FE-TEM) (JEM-ARM 200F, manufactured by japan electronics corporation), the image magnification was set to 5 ten thousand times, 20 metal-containing particles were randomly selected, and the convex portions and protrusions of each metal-containing particle were observed. The diameters of the bases of the convex portions and the protrusions of the obtained metal-containing particles were measured, and the average base diameters of the convex portions and the protrusions were determined by arithmetic averaging.

(3) Observation of the shape of the convex part and the protrusion

Using a scanning electron microscope (FE-SEM), the image magnification was set to 25000 times, 20 metal-containing particles were randomly selected, the convex portions and protrusions of each metal-containing particle were observed, and the types of all the convex portions and the shapes belonging to the protrusions were examined.

(4) Measurement of average apex angle of convex portion and protrusion

The obtained metal-containing particles were added to "Technovit 4000" manufactured by Kulzer, and dispersed so that the content thereof became 30% by weight, thereby producing embedded resins for metal-containing particle inspection. The cross section of the metal-containing particles was cut out by an ion milling device ("IM 4000", manufactured by hitachi high-tech corporation) so as to be dispersed in the vicinity of the center of the metal-containing particles in the inspection resin.

Then, 20 metal-containing particles were randomly selected with an image magnification set to 100 ten thousand times using a field emission transmission electron microscope (FE-TEM) (JEM-ARM 200F, manufactured by japan electronics corporation), and the protrusions of the respective metal-containing particles were observed. The apex angles of the convex portions and the protrusions in the obtained metal-containing particles were measured, and the values were arithmetically averaged to obtain an average value of the apex angles of the convex portions and the protrusions.

(5) Measurement of average diameter at center of height of convex portion and protrusion

The obtained metal-containing particles were added to "Technovit 4000" manufactured by Kulzer, and dispersed so that the content thereof became 30% by weight, thereby producing embedded resins for metal-containing particle inspection. The cross section of the metal-containing particles was cut out by an ion milling device ("IM 4000" manufactured by hitachi high-tech corporation) so as to be dispersed in the vicinity of the center of the metal-containing particles in the inspection resin.

Then, 20 metal-containing particles were randomly selected with an image magnification set to 5 ten thousand times using a field emission transmission electron microscope (FE-TEM) (JEM-ARM 200F, manufactured by japan electronics corporation), and the protrusions of the respective metal-containing particles were observed. The diameters of the base portions of the convex portions and the protrusions in the obtained metal-containing particles were measured, and the average diameter at the center of the heights of the convex portions and the protrusions was obtained by arithmetic averaging the diameters.

(6) Measurement of the ratio of the number of needle-like projections and protrusions

Using a scanning electron microscope (FE-SEM), 20 metal-containing particles were randomly selected with an image magnification of 25000 times, and the convex portions and protrusions of the respective metal-containing particles were observed. All the projections and protrusions are classified into: whether or not the shape of the convex portion and the shape of the protrusion are of a needle shape with a tapered tip is evaluated, and the difference is that the shape of the convex portion and the shape of the protrusion are a convex portion and a protrusion formed of a needle shape with a tapered tip, and a convex portion and a protrusion formed of a needle shape with a convex portion shape and a protrusion shape other than a needle shape with a tapered tip. As described above, the number of 1) projections and protrusions formed by a needle-like shape whose tip is tapered and 2) projections and protrusions formed by a needle-like shape other than the sharp needle-like shape were measured for 1 metal-containing particle. The ratio X of the number of needle-like projections and protrusions was calculated as 1) out of 100% of the total number of projections of 1) and 2).

(7) Measurement of thickness of Metal part without convex portion and protruding portion

The obtained metal-containing particles were added to "Technovit 4000" manufactured by Kulzer, and dispersed so that the content thereof became 30% by weight, thereby producing embedded resins for metal-containing particle inspection. The cross section of the metal-containing particles was cut out by dispersing the particles in the vicinity of the center of the metal-containing particles in the embedded resin for inspection using an ion milling apparatus ("IM 4000", manufactured by hitachi high-tech co.

Then, using a field emission transmission electron microscope (FE-TEM) (JEM-ARM 200F, manufactured by japan electronics corporation), an image magnification was set to 5 ten thousand times, 20 metal-containing particles were randomly selected, and the metal portion of each metal-containing particle where no protruding portion exists was observed. The thickness of the entire metal portion in the non-protrusion portion of the obtained metal-containing particles was measured, and the thickness (average thickness) was obtained by arithmetically averaging the thicknesses (described in the above examples and comparative examples).

(8) Compressive modulus of elasticity (10% K value) of the Metal-containing particles

The modulus of elasticity under compression (10% K value) of the metal-containing particles obtained was measured at 23 ℃ by the method described above using a micro compression tester ("FISCOPE H-100" manufactured by FISCER K.K.). The 10% K value was determined.

(9) Evaluation of surface lattice of Metal portion

The peak intensity ratio of diffraction lines specific to the device depending on the diffraction angle was calculated using an X-ray diffraction device ("RINT 2500 VHF" manufactured by chem motors). The ratio of the diffraction peak intensity of the (111) azimuth to the diffraction peak intensity of the diffraction line of the metal layer as a whole (the ratio of the (111) plane) was obtained.

(10) Molten and solidified state of the tip of the projection of the metal portion in the connection structure body a

The obtained metal-containing particles were dispersed in "struct. bond XN-5A" manufactured by Mitsui chemical corporation to a content of 10% by weight, to prepare an anisotropic conductive paste.

A transparent glass substrate having a copper electrode pattern with an L/S of 30 μm/30 μm on the upper surface was prepared. In addition, a semiconductor chip having a gold electrode pattern with an L/S of 30 μm/30 μm on the lower surface was prepared.

The transparent glass substrate was coated with the anisotropic conductive paste after fabrication to form an anisotropic conductive paste layer to a thickness of 30 μm. Next, the semiconductor chips are stacked on the anisotropic conductive paste layer, and the electrodes L are opposed to each other. Thereafter, while adjusting the temperature of the head so that the temperature of the anisotropic conductive paste layer became 250 ℃, a pressure heating head was placed on the upper surface of the semiconductor chip, and a pressure of 0.5MPa was applied to cure the anisotropic conductive paste layer at 250 ℃. In order to obtain a connection structure A, the electrodes were connected at a low pressure of 0.5 MPa.

The obtained connection structure was placed in "Technovit 4000" manufactured by Kulzer, and cured to prepare an embedding resin for connection structure inspection. The cross section of the metal-containing particles was cut out so as to pass through the vicinity of the center of the connection structure in the inspection resin using an ion milling apparatus ("IM 4000" manufactured by hitachi high-tech corporation).

Then, whether or not the obtained connection structure a is solidified after the tips of the protrusions of the metal portion of the metal-containing particles are melted is determined by observing the cross section using a scanning electron microscope (FE-SEM).

[ criteria for determining the molten and solidified states of the tips of the projections of the metal part ]

A: solidifying the metal part after the tip of the protrusion of the metal part is melted

B: the front end of the protrusion of the metal part is not solidified after being melted

(11) Connection structure A having metal part protruding therefrom

In the connection structure a obtained in the above evaluation of (10), the connection structure a was observed in a cross section to determine the joint state of the protrusions of the metal portions.

[ criterion for determining the bonding state of the projections of the metal part ]

A: in the connecting portion, the tip of the protrusion of the metal portion among the metal-containing particles is melted and then solidified, and is joined to the electrode and other metal-containing particles.

B: in the connecting portion, the tips of the protrusions of the metal portion among the metal-containing particles are solidified after being melted, and are not bonded to the electrode and other metal-containing particles.

(12) Connection reliability in connection structure A

The connection resistance between 15 upper and lower electrodes of the connection structure a obtained in the above (10) evaluation was measured by the 4-terminal method. The average value of the connection resistance was calculated. The connection resistance can be determined by measuring the voltage when a constant current is applied, from the relationship of voltage to current × resistance. The connection reliability was determined by the following criteria.

[ criterion for determining connection reliability ]

O ≈: the connection resistance is 1.0 omega or less

O ^ O: the connection resistance is more than 1.0 omega and less than 2.0 omega

O: the connection resistance is more than 2.0 omega and less than 3.0 omega

And (delta): the connection resistance is more than 3.0 omega and less than 5 omega

X: the connection resistance exceeds 5 omega

(13) Molten and solidified state of the tip of the protrusion of the metal part in the connection structure B

The obtained metal-containing particles were added to "ANP-1" (particles containing a metal atom) manufactured by japan super corp, and dispersed so that the content was 5 wt, thereby preparing a sintered silver paste.

As a first connection target member, a power semiconductor element having a connection surface plated with Ni/Au was prepared. As the second connection target member, an aluminum nitride substrate having a connection surface plated with Cu was prepared.

The sintered silver paste was applied to the second member to be connected to form a silver paste layer for connection so that the thickness thereof was about 70 μm. Then, the first connection target member was laminated on the connection silver paste layer to obtain a laminated body.

The obtained laminate was preheated at 130 ℃ for 60 seconds, and then heated at 300 ℃ for 3 minutes under a pressure of 10MPa, thereby sintering the metal atom-containing particles contained in the sintered silver paste to form a connection portion containing a sintered material and metal-containing particles, and the first connection object member and the second connection object member were joined to each other by the sintered material to obtain a connection structure B.

The obtained connection structure was placed in "Technovit 4000" manufactured by Kulzer, and cured to prepare an embedding resin for connection structure inspection. The cross section of the metal-containing particles was cut out so as to pass through the vicinity of the center of the connection structure embedded in the inspection resin using an ion milling apparatus ("IM 4000" manufactured by hitachi high-tech).

The obtained connection structure B was observed in cross section by using a scanning electron microscope (FE-SEM). It is determined whether or not the metal part of the metal-containing particles is solidified after the tip of the protrusion is melted.

(14) Connection structure B having metal part protruding therefrom

The connection structure B obtained in the above evaluation (13) was observed in a cross section to determine the bonding state of the protrusions of the metal portions.

A: in the connecting portion, the tips of the protrusions of the metal portion among the metal-containing particles are melted and then solidified, and are joined to the electrode and other metal-containing particles.

B: in the connecting portion, the tip of the protrusion of the metal portion among the metal-containing particles is melted and then solidified, and is not bonded to the electrode and other metal-containing particles.

(15) Connection reliability of connection structure B

The connection structure B obtained in the above evaluation (13) was added to a thermal shock tester (TSA-101S-W, manufactured by ESPEC corporation), the treatment conditions of holding at a minimum temperature of-40 ℃ for 30 minutes and at a maximum temperature of 200 ℃ for 30 minutes were set to 1 cycle, and after 3000 cycles, the joint strength was measured by a shear strength tester (STR-1000, manufactured by Rhesca corporation). The connection reliability was determined by the following criteria.

[ criterion for determining connection reliability ]

O ≈: the bonding strength is 50MPa or more

O ^ O: the bonding strength is more than 40MPa and less than 50MPa

O: the bonding strength is more than 30MPa and less than 40MPa

And (delta): the bonding strength is more than 20MPa and less than 30MPa

X: the bonding strength is 20MPa or less

(16) Contact resistance value of conduction inspection component

10 parts by weight of a polysiloxane-based copolymer, 90 parts by weight of the obtained metal-containing particles, 1 part by weight of an epoxy silane coupling agent ("KBE-303", manufactured by shin-Etsu chemical Co., Ltd.), and 36 parts by weight of isopropyl alcohol were mixed, and the mixture was stirred at 1000rpm for 20 minutes by a high-speed disperser, and then defoamed by "Margar ARE 250", manufactured by THINKY corporation, to prepare a conductive material containing the metal-containing particles and a binder.

The polysiloxane copolymer described above was polymerized by the following method. A metal kneader having an internal volume of 2L was charged with 162g (628mmol) of 4, 4' -dicyclohexylmethane diisocyanate ("Degussa corporation") and 900g (90mmol) of one-terminal amino-modified polydimethylsiloxane ("TSF 4709" manufactured by Meiji corporation) (molecular weight 10000), and the mixture was dissolved at 70 to 90 ℃ and stirred for 2 hours. Thereafter, 65g (625mmol) of neopentyl glycol (manufactured by Mitsubishi gas chemical) was gradually added thereto, and kneaded for 30 minutes, and then unreacted neopentyl glycol was removed under reduced pressure. The obtained polysiloxane copolymer was dissolved in isopropanol to make 20 wt% and used. The disappearance of the isocyanate group was confirmed by IR spectroscopy. In the resulting polysiloxane-based copolymer, the polysiloxane content was 80% by weight, the weight average molecular weight was 25000, the SP value was 7.8, and the SP value of the repeating unit of the structure (polyurethane) having a polar group was 10.

Next, silicone rubber was prepared as a base material (sheet-like base material made of an insulating material) of the conduction test member. The organic rubber had dimensions of 25mm in transverse width, 25mm in longitudinal width and 1mm in thickness. In the silicone rubber, 20 cylindrical through holes having a diameter of 0.5mm were formed in the vertical direction and 20 cylindrical through holes having a diameter of 400 in total were formed in the horizontal direction by laser processing.

The conductive material is applied to the silicone rubber having the through-hole by using a knife coater, and the through-hole is filled with the conductive material. Subsequently, the silicone rubber having the through-holes filled with the conductive material was dried in an oven at 50 ℃ for 10 minutes, and then further dried at 100 ℃ for 20 minutes to obtain a conduction test member having a thickness of 1 mm.

The contact resistance value of the obtained conduction test member was measured using a contact resistance measurement system ("MS 7500" manufactured by fatk corporation). For the contact resistance measurement, a platinum probe having a diameter of 0.5mm was used to apply pressure in a direction perpendicular to the conductive portion of the conduction testing member obtained under a load of 15 gf. At this time, a low resistance meter ("MODEL 3566" manufactured by Hakka electric Co., Ltd.) was charged with 5V to measure a contact resistance value. The average value of the contact connection resistance values of the conductive parts at 5 points was calculated. The contact resistance value was determined by the following criteria.

[ criterion for determining contact resistance value ]

O ^ O: the average value of the connection resistance is 50.0m omega or less

O: the average value of the connection resistance is more than 50.0m omega and less than 100.0m omega

And (delta): the average value of the connection resistance is more than 100.0m omega and less than 500.0m omega

X: the average value of the connection resistance exceeds 500.0m omega

(17) Repeated reliability test of component for conduction inspection

The conduction testing member for evaluation of the contact resistance value of the conduction testing member (16) is prepared.

The repetitive reliability test and the contact resistance value of the obtained conduction test member were measured using a contact resistance measurement system ("MS 7500" manufactured by fatk corporation). For the repeated reliability test, pressurization was repeated 1000 times with a platinum probe having a diameter of 0.5mm from a direction perpendicular to the conductive portion of the probe sheet obtained under a load of 15 gf. After the pressurization was repeated 1000 times, 5V was applied by a low resistance meter ("MODEL 3566" manufactured by Hakka electric Co., Ltd.), and the contact resistance value was measured. Similarly, the average value of the contact resistance values of the conductive portions at 5 points was measured. The contact resistance value was determined by the following criteria.

[ criterion for determining contact resistance value after repeated pressurization ]

O ^ O: the average value of the connection resistance is less than 100.0m omega

O: the average value of the connection resistance is more than 100.0m omega and less than 500.0m omega

And (delta): the average value of the connection resistance is more than 500.0m omega and less than 1000.0m omega

X: the average value of the connection resistance exceeds 1000.0m omega

The compositions and results are shown in tables 1 to 5.

[ Table 1]

[ Table 2]

[ Table 3]

[ Table 4]

[ Table 5]

The spherical shape of the convex portion and the protrusion includes a shape of a part of the ball. In comparative examples 1 and 2, it was confirmed that the tips of the protrusions were not melted even when heated to 400 ℃.

Claims

1. A metal-containing particle comprising:

substrate particles, and

a metal portion disposed on the surface of the base particle,

the base material particles are base material particles other than metal particles,

the metal part has a plurality of convex parts on an outer surface,

the metal part has a plurality of protrusions on an outer surface of the convex part,

the tip of the protrusion of the metal part can be melted at 400 ℃ or less.

2. The metal-containing particle of claim 1,

the ratio of the average height of the convex portions to the average height of the protrusions is 5 or more and 1000 or less.

3. The metal-containing particle of claim 1 or 2,

the average diameter of the base of the projection is 3nm to 5000 nm.

4. The metal-containing particle of claim 1 or 2,

the surface area of a portion where the convex portion is present is 10% or more of the total surface area 100% of the outer surface of the metal portion.

5. The metal-containing particle of claim 1 or 2,

the shape of the convex part is a needle shape or a shape of a part of a sphere.

6. The metal-containing particle of claim 1 or 2,

the average value of the apex angle of the protrusions is 10 DEG to 60 deg.

7. The metal-containing particle of claim 1 or 2,

the average height of the protrusions is 3nm to 5000 nm.

8. The metal-containing particle of claim 1 or 2,

the average diameter of the base of the protrusion is 3nm to 1000 nm.

9. The metal-containing particle of claim 1 or 2,

the ratio of the average height of the protrusions to the average diameter of the base of the protrusions is 0.5 to 10.

10. The metal-containing particle of claim 1 or 2,

the shape of the protrusion is a needle shape or a shape of a part of a sphere.

11. The metal-containing particle of claim 1 or 2,

the material of the protrusions comprises silver, copper, gold, palladium, tin, indium or zinc.

12. The metal-containing particle of claim 1 or 2,

the material of the metal part is not solder.

13. The metal-containing particle of claim 1 or 2,

the material of the metal portion includes silver, copper, gold, palladium, tin, indium, zinc, nickel, cobalt, iron, tungsten, molybdenum, ruthenium, platinum, rhodium, iridium, phosphorus, or boron.

14. The metal-containing particle of claim 1 or 2,

the tip of the protrusion of the metal part can be melted at 350 ℃ or less.

15. The metal-containing particle of claim 14,

the tip of the protrusion of the metal part can be melted at 300 ℃ or less.

16. The metal-containing particle of claim 15,

the tip of the protrusion of the metal part can be melted at 250 ℃ or less.

17. The metal-containing particle of claim 16,

the tip of the protrusion of the metal part can be melted at 200 ℃ or less.

18. Metal-containing particles according to claim 1 or 2, having a modulus of elasticity under compression of 100N/mm when subjected to 10% compression²Above 25000N/mm²The following.

19. The metal-containing particle of claim 1 or 2,

the substrate particles are polysiloxane particles.

20. A connecting material, comprising:

the metal-containing particles and resin of any one of claims 1-19.

21. A connection structure body is provided with:

a first member to be connected,

A second member to be connected,

A connecting portion that connects the first connection target member and the second connection target member together,

the material of the connecting part is the metal-containing particle described in any one of claims 1 to 19; or a connecting material containing the metal-containing particles and a resin.

22. A method of manufacturing a connection structure, comprising:

disposing the metal-containing particle according to any one of claims 1 to 19 or a connecting material containing the metal-containing particle and a resin between a first member to be connected and a second member to be connected;

and a step of heating the metal-containing particles to melt and solidify the tips of the protrusions of the metal part, and forming a connection portion for connecting the first connection target member and the second connection target member together using the metal-containing particles or the connection material.