JP2019046801A - Base material particle, conductive particle, conductive material and connection structure - Google Patents

Abstract

To provide conductive particles capable of making the connection resistance low, even when the pressure bonding is performed under low pressure in the case of electrically connecting between electrodes.SOLUTION: A conductive particle according to the present invention is a conductive particle that includes: a base material particle; and a conductive part arranged on a surface of the base material particle, in which when an area of the conductive particle and an area of a rectangle circumscribing the conductive particle are calculated from an electron microscope image or an optical microscope image of the conductive particle, a ratio of an area of the conductive particle to an area of the rectangle circumscribing to the conductive particle is 0.80 or larger.SELECTED DRAWING: Figure 1

Description

  The present invention relates to substrate particles used to obtain conductive particles having a conductive portion. In addition, the present invention relates to a conductive particle, a conductive material and a connection structure using substrate particles.

  Anisotropic conductive materials such as anisotropic conductive paste and anisotropic conductive film are widely known. In the anisotropic conductive material, conductive particles are dispersed in a binder.

  The said anisotropic conductive material is used in order to electrically connect between the electrodes of various connection object members, such as a flexible printed circuit board (FPC), a glass substrate, a glass epoxy substrate, and a semiconductor chip, and to obtain a connection structure. ing. Moreover, the electroconductive particle which has a base material particle and the electroconductive part arrange | positioned on the surface of this base material particle may be used as said electroconductive particle.

  As an example of the said electroconductive particle, in the following patent document 1, the electroconductive particle which has a polymer particle and the electroconductive part which has coat | covered the surface of this polymer particle is disclosed. The above-mentioned polymer particles are monofunctional with at least one polyfunctional (meth) acrylate of difunctional (meth) acrylate monomers, trifunctional (meth) acrylate monomers, and tetrafunctional (meth) acrylate monomers. It is obtained by copolymerizing the copolymerization component containing the (meth) acrylate monomer. The compression deformation recovery rate of the polymer particles is 70% or more. The volume expansion coefficient of the polymer particles is 1.3 or less.

WO 2010/013668 A1

  In conventional conductive particles, when the electrodes are electrically connected at relatively low pressure, the connection resistance between the electrodes may be high. This is because the conductive particles do not deform sufficiently at relatively low pressure, and the conductive particles and the electrode do not contact sufficiently. For this reason, in the case of using conventional conductive particles, a relatively high pressure is required to sufficiently deform the conductive particles.

  However, when the electrodes are electrically connected at relatively high pressure, although the substrate particles or the conductive particles can be deformed, the electrodes may be scratched to increase the connection resistance. In addition, the action of returning compressed base particles or conductive particles to their original shape may act to cause a phenomenon called springback. When springback occurs in the substrate particles or the conductive particles, the contact area between the conductive particles and the electrode may be reduced, the connection resistance may be increased, and the conduction reliability may be reduced.

  An object of the present invention is to provide substrate particles capable of reducing connection resistance even when pressure bonding is performed at low pressure when electrically connecting electrodes. Another object of the present invention is to provide a conductive particle, a conductive material and a connection structure using substrate particles.

  According to a broad aspect of the present invention, there is provided a conductive particle comprising a substrate particle and a conductive portion disposed on the surface of the substrate particle, wherein an electron microscope image or an optical microscope image of the conductive particle When the area of the conductive particle and the area of the rectangle circumscribing the conductive particle are calculated, the ratio of the area of the conductive particle to the area of the rectangle circumscribing the conductive particle is 0.80 or more Certain conductive particles are provided.

In a specific aspect of the conductive particles according to the present invention, the 10% K value is 3200 N / mm ² or less.

  In a specific aspect of the conductive particles according to the present invention, the compression recovery rate at 60% compression deformation is 15% or less.

  In a specific aspect of the conductive particles according to the present invention, the substrate particles are resin particles.

  In a specific aspect of the conductive particle according to the present invention, the resin particle contains an acrylic resin or a silicone resin.

  In one specific aspect of the conductive particle according to the present invention, the conductive particle further includes an insulating material disposed on the outer surface of the conductive portion.

  In a specific aspect of the conductive particle according to the present invention, the conductive particle has a protrusion on the outer surface of the conductive portion.

According to a broad aspect of the present invention, it is a substrate particle used to obtain conductive particles having a conductive portion, and a 10% K value of the substrate particle is 2000 N / mm ² or less, and the substrate When the area of the base particle and the area of a rectangle circumscribing the base particle are calculated by an electron microscope image or an optical microscope image of the particle, the base particle is circumscribed about the area of the base particle. Substrate particles are provided, wherein the ratio to the area of the rectangle is 0.80 or more.

  In one particular aspect of the substrate particles according to the present invention, the compression recovery rate at 60% compression is 15% or less.

  In a specific aspect of the substrate particle according to the present invention, the substrate particle is a resin particle.

  In a specific aspect of the substrate particle according to the present invention, the resin particle contains an acrylic resin or a silicone resin.

  According to a broad aspect of the present invention, there is provided a conductive material comprising conductive particles and a binder resin, wherein the conductive particles are the above-described conductive particles.

  According to a broad aspect of the present invention, a conductive material comprising conductive particles and a binder resin, wherein the conductive particles comprise the above-described base particles and a conductive portion disposed on the surface of the base particles Conductive particles are provided, which are

  According to a broad aspect of the present invention, a first connection target member having a first electrode on the surface, a second connection target member having a second electrode on the surface, the first connection target member, and the first connection target member And a connecting portion connecting the second connection target member, and the material of the connecting portion is a conductive particle, or a conductive material containing the conductive particle and a binder resin, the conductive A connection structure is provided, in which the conductive particles are the above-described conductive particles, and the first electrode and the second electrode are electrically connected by the conductive particles.

  According to a broad aspect of the present invention, a first connection target member having a first electrode on the surface, a second connection target member having a second electrode on the surface, the first connection target member, and the first connection target member And a connecting portion connecting the second connection target member, and the material of the connecting portion is a conductive particle, or a conductive material containing the conductive particle and a binder resin, the conductive Conductive particles are conductive particles provided with the above-mentioned base material particles and a conductive portion disposed on the surface of the base material particles, and the first electrode and the second electrode are the conductive particles A connection structure is provided which is electrically connected by

  The electroconductive particle which concerns on this invention is equipped with a base material particle and the electroconductive part arrange | positioned on the surface of the said base material particle. In the conductive particle according to the present invention, when the area of the conductive particle and the area of the rectangle circumscribing the conductive particle are calculated by the electron microscope image or the optical microscope image of the conductive particle, The ratio of the area of particles to the area of a rectangle circumscribing the conductive particles is 0.80 or more. The conductive particle according to the present invention is provided with the above-described configuration, so that, when electrically connecting the electrodes, connection resistance can be lowered even if pressure bonding is performed at a low pressure.

The substrate particles according to the present invention are used to obtain conductive particles having a conductive portion. In the substrate particle according to the present invention, the 10% K value of the substrate particle is 2000 N / mm ² or less. In the substrate particle according to the present invention, when the area of the substrate particle and the area of the rectangle circumscribing the substrate particle are calculated by the electron microscope image or the optical microscope image of the substrate particle, the substrate The ratio of the area of particles to the area of a rectangle circumscribing the base particles is 0.80 or more. In the substrate particle according to the present invention, since the above-described configuration is provided, pressure bonding is performed at a low pressure when electrically connecting the electrodes using the substrate particle as conductive particles. Also, the connection resistance can be lowered.

FIG. 1 is a cross-sectional view showing a conductive particle according to a first embodiment of the present invention. FIG. 2 is a cross-sectional view showing a conductive particle according to a second embodiment of the present invention. FIG. 3 is a cross-sectional view showing a conductive particle according to a third embodiment of the present invention. FIG. 4 is a cross-sectional view showing a modification of the conductive particle according to the first embodiment of the present invention. FIG. 5: is sectional drawing which shows an example of the bonded structure using the electroconductive particle which concerns on the 1st Embodiment of this invention. FIGS. 6A and 6B are schematic views for explaining the area of the conductive particle and the area of the rectangle circumscribing the conductive particle in the conductive particle according to the present invention. FIGS. 7A and 7B are schematic views for explaining the area of substrate particles and the area of a rectangle circumscribing the substrate particles in the substrate particles according to the present invention.

  Hereinafter, the present invention will be described in detail.

(Conductive particles)
The electroconductive particle which concerns on this invention is equipped with a base material particle and the electroconductive part arrange | positioned on the surface of the said base material particle. In the conductive particle according to the present invention, when the area of the conductive particle and the area of the rectangle circumscribing the conductive particle are calculated by the electron microscope image or the optical microscope image of the conductive particle, The ratio of the area of particles to the area of a rectangle circumscribing the conductive particles is 0.80 or more.

  In the present invention, since the above configuration is provided, the connection resistance can be lowered even when the pressure bonding is performed under a low pressure when the electrodes are electrically connected.

  In the conductive particle according to the present invention, the above configuration is provided, so that the contact area between the conductive particle and the electrode can be sufficiently secured even when the electrodes are electrically connected at a relatively low pressure. And the connection resistance can be made sufficiently low.

  Further, in the conductive particle according to the present invention, since it is not necessary to increase the pressure when electrically connecting the electrodes, scratching of the electrodes can be effectively suppressed, and the connection resistance is sufficiently low. can do. Further, in the conductive particles according to the present invention, since it is not necessary to increase the pressure when electrically connecting the electrodes, the function of returning the compressed conductive particles to their original shape is relatively difficult to work. , Springback is hard to occur. In the conductive particle according to the present invention, the reduction of the contact area between the conductive particle and the electrode can be effectively prevented, the connection resistance can be sufficiently lowered, and the conduction reliability can be effectively enhanced. Can.

  The electroconductive particle which concerns on this invention is equipped with a base material particle and the electroconductive part arrange | positioned on the surface of the said base material particle. In the conductive particles according to the present invention, it is preferable that the substrate particles according to the present invention described later be provided.

  FIG. 1 is a cross-sectional view showing a conductive particle according to a first embodiment of the present invention.

  The conductive particle 1 shown in FIG. 1 has a substrate particle 11 and a conductive portion 2 disposed on the surface of the substrate particle 11. The conductive portion 2 covers the surface of the base particle 11. The conductive particle 1 is a coated particle in which the surface of the substrate particle 11 is covered by the conductive portion 2. In the conductive particle 1, the conductive part 2 is a single layer conductive part (conductive layer). In the conductive particle 1, the side surface of the central portion in the longitudinal direction is planar.

  FIG. 4 is a cross-sectional view showing a modification of the conductive particle according to the first embodiment of the present invention. The conductive particle 1X shown in FIG. 4 has a base particle 11X and a conductive portion 2X disposed on the surface of the base particle 11X. In the conductive particle 1X, the side surface of the central portion in the length direction is convex and curved. In the conductive particle 1X, the side surface of the central portion in the lengthwise direction of the base particle 11X is convex and curved. In the conductive particle according to the present invention, the side surface of the central portion in the length direction may be flat like the conductive particle 1, and the side surface of the central portion in the length direction is convex like the conductive particle 1X It may be shaped like a circle or a curved surface. In the conductive particle according to the present invention, the side surface of the central portion in the longitudinal direction may be planar, and the side surface of the central portion in the longitudinal direction may not be planar. As a shape in which the side surface of the central portion in the longitudinal direction is not planar, convex and concave shapes and the like can be mentioned.

  FIG. 2 is a cross-sectional view showing a conductive particle according to a second embodiment of the present invention.

  The conductive particle 21 shown in FIG. 2 has a substrate particle 11 and a conductive portion 22 disposed on the surface of the substrate particle 11. The conductive portion 22 as a whole has a first conductive portion 22A on the base particle 11 side and a second conductive portion 22B on the opposite side to the base particle 11 side.

  The conductive part 2 and the conductive part 22 are different between the conductive particle 1 shown in FIG. 1 and the conductive particle 21 shown in FIG. That is, in the conductive particle 1, the conductive portion having a single-layer structure is formed, whereas in the conductive particle 21, the first conductive portion 22A and the second conductive portion 22B having a two-layer structure are formed. There is. The first conductive portion 22A and the second conductive portion 22B may be formed as different conductive portions, or may be formed as the same conductive portion.

  The first conductive portion 22 </ b> A is disposed on the surface of the base particle 11. The first conductive portion 22A is disposed between the base particle 11 and the second conductive portion 22B. The first conductive portion 22 </ b> A is in contact with the base particle 11. The second conductive portion 22B is in contact with the first conductive portion 22A. The first conductive portion 22A is disposed on the surface of the base particle 11, and the second conductive portion 22B is disposed on the surface of the first conductive portion 22A.

  FIG. 3 is a cross-sectional view showing a conductive particle according to a third embodiment of the present invention.

  The conductive particle 31 shown in FIG. 3 has a substrate particle 11, a conductive portion 32, a plurality of core materials 33, and a plurality of insulating materials 34. The conductive portion 32 is disposed on the surface of the base particle 11. The plurality of core substances 33 are disposed on the surface of the base particle 11. The conductive portion 32 is disposed on the surface of the base material particle 11 so as to cover the base material particle 11 and the plurality of core substances 33. In the conductive particle 31, the conductive part 32 is a single layer conductive part (conductive layer).

  The conductive particles 31 have a plurality of protrusions 31 a on the outer surface. In the conductive particle 31, the conductive portion 32 has a plurality of protrusions 32a on the outer surface. The plurality of core substances 33 raise the outer surface of the conductive portion 32. The projections 31 a and the projections 32 a are formed by the outer surface of the conductive portion 32 being raised by the plurality of core materials 33. A plurality of core substances 33 are embedded in the conductive portion 32. The core material 33 is disposed inside the protrusions 31 a and the protrusions 32 a. In the conductive particles 31, a plurality of core substances 33 are used to form the protrusions 31a and the protrusions 32a. In the conductive particles, a plurality of the core substances may not be used to form the protrusions. The conductive particles may not include a plurality of the core materials.

  The conductive particles 31 have an insulating material 34 disposed on the outer surface of the conductive portion 32. At least a partial region of the outer surface of conductive portion 32 is covered with insulating material 34. The insulating substance 34 is formed of an insulating material and is an insulating particle. Thus, the conductive particles according to the present invention may have an insulating material disposed on the outer surface of the conductive portion. However, the conductive particles may not necessarily have an insulating substance. The conductive particles may not have a plurality of insulating materials.

  The major diameter of the conductive particles is preferably 5 μm or more, more preferably 10 μm or more, preferably 50 μm or less, more preferably 40 μm or less, and still more preferably 35 μm or less. When the major diameter of the conductive particle is not less than the lower limit and not more than the upper limit, the contact area between the conductive particle and the electrode becomes sufficiently large when the conductive particles are used to connect the electrodes, so the connection resistance Can be lowered, and it becomes difficult to form aggregated conductive particles when forming the conductive portion. In addition, when the major diameter of the conductive particle is not less than the lower limit and not more than the upper limit, the distance between the electrodes connected via the conductive particle is not too large, and the conductive portion is from the surface of the base particle It becomes difficult to peel off. Moreover, a conductive particle can be suitably used for the use of a conductive material as the major axis of the above-mentioned conductive particle is more than the above-mentioned lower limit and below the above-mentioned upper limit.

  The major diameter of the conductive particle can be calculated, for example, by observing any conductive particle with an electron microscope or an optical microscope. The major axis of the conductive particle is a dimension at which a distance obtained by connecting two points on the outer periphery of the conductive particle by a straight line becomes maximum.

  The major diameter of the above conductive particles may be determined by observing 50 arbitrary conductive particles with an electron microscope or an optical microscope and calculating the average value by arithmetically averaging the major diameters of 50 arbitrary conductive particles. preferable.

  In the conductive particle according to the present invention, when the area of the conductive particle and the area of the rectangle circumscribing the conductive particle are calculated by the electron microscope image or the optical microscope image of the conductive particle, The ratio of the area of the particle to the area of the rectangle circumscribing the conductive particle (area of the conductive particle / area of the rectangle circumscribing the conductive particle) is 0.80 or more. As the above ratio (area of conductive particle / area of rectangle circumscribing conductive particle) is larger, the conductive particle has a shape closer to a rectangle. The aspect ratio of the conductive particles according to the present invention is generally more than one. The aspect ratio (long diameter / short diameter) of the conductive particles according to the present invention may be 5 or less, or 3 or less.

  The quadrilateral circumscribing the conductive particles is not a square but a rectangle. The rectangle circumscribing the conductive particles is drawn such that the area of the rectangle circumscribing the conductive particles is minimized.

  FIGS. 6A and 6B are schematic views for explaining the area of the conductive particle and the area of the rectangle circumscribing the conductive particle in the conductive particle according to the present invention. 6A and 6B show an electron microscope image of the conductive particle 1 obtained by observing the above-described conductive particle 1 with an electron microscope, and a rectangle 51 circumscribing the conductive particle 1 and Is schematically shown.

  The area of the said electroconductive particle is an area (S1) of the electroconductive particle 1 in Fig.6 (a). The area of the rectangle circumscribing the conductive particles is the area (S2) of the rectangle 51 circumscribing the conductive particles 1 in FIG. 6B. The ratio of the area of the conductive particle to the area of the rectangle circumscribing the conductive particle is the ratio of the area (S1) of the conductive particle 1 to the conductive particle 1 in FIGS. 6 (a) and 6 (b). It is a ratio (S1 / S2) to the area (S2) of the circumscribed rectangle 51.

  From the viewpoint of effectively reducing the connection resistance, the ratio (area of conductive particles / area of rectangle circumscribing conductive particles) in the conductive particles is preferably 0.82 or more, more preferably 0. 85 or more. The ratio (area of conductive particles / area of rectangle circumscribing conductive particles) in the conductive particles is preferably 1.0 or less, more preferably less than 1.0.

  In the observation, it is preferable that the conductive particles do not reach the four apexes of the rectangle circumscribing the conductive particles.

  The ratio (area of conductive particle / area of rectangle circumscribing conductive particle) in the conductive particle is obtained by observing 50 arbitrary conductive particles with an electron microscope or an optical microscope. It is preferable to obtain | require by calculating the average value by carrying out the arithmetic mean of the above-mentioned ratio (area of a conductive particle / area of the rectangle circumscribed to a conductive particle).

  In the conductive particle according to the present invention, the above-mentioned ratio (area of conductive particle / area of rectangle circumscribing conductive particle) is 0.80 or more. When the shape of the conductive particle is a true sphere, the ratio (the area of the conductive particle / the area of the rectangle circumscribing the conductive particle) is 0.785. The shape is not spherical. The shape of the conductive particles according to the present invention is not particularly limited as long as the above-described relationship is satisfied. The shape of the conductive particles according to the present invention may be columnar or may be bowl-like.

  When the conductive particles have a shape satisfying the above-described relationship, the contact area between the conductive particles and the electrodes becomes large when the electrodes are electrically connected, so that the pressure at the time of connection is the above. It is uniformly applied to the whole conductive particle. As a result, the occurrence of plating cracks of the conductive particles can be more effectively suppressed, and the connection resistance can be further lowered. When the conductive particles are spherical, when the electrodes are electrically connected, the contact area between the conductive particles and the electrodes is small, and the pressure at the time of connection is locally applied to the conductive particles. May be granted. As a result, plating cracks of the conductive particles are likely to occur, which may make it difficult to reduce the connection resistance.

  The conductive particles satisfying the above ratio (area of conductive particles / area of rectangle circumscribing conductive particles) can be obtained by using base particles of a predetermined shape (for example, columnar or bowl-like base particles). You can get it. Substrate particles of a predetermined shape can be obtained by adjusting the production conditions at the time of formation of the substrate particles, or adjusting the production conditions and the 10% K value of the substrate particles to be formed. . For example, at the time of formation of substrate particles, substrate particles having a predetermined shape can be obtained by applying a force to knead the substrate particles.

10% K value of the conductive particles is preferably 2000N / mm ² or more, more preferably 2300N / mm ² or more, preferably 3200N / mm ² or less, more preferably 3000N / mm ² or less, more preferably It is 2800 N / mm ² or less. When the 10% K value of the conductive particles is above the lower limit and below the upper limit, the occurrence of spring back can be further effectively suppressed, and the conduction reliability can be more effectively enhanced. it can.

  The 10% K value (the compression modulus when the conductive particles are compressed by 10%) of the conductive particles can be measured as follows.

  Place conductive particles on the sample table. The conductive particles are in a stationary state by gravity. It is preferable to place the conductive particles in the most stabilized stationary state. In general, the longitudinal direction of the conductive particles is in the lateral direction. Using a micro compression tester, with a cylindrical (diameter 100 μm, made of diamond) smooth indenter end face, one conductive particle under the conditions of a compression speed of 0.3 mN / s and a maximum test load of 20 mN at 25 ° C Compress in the vertical direction on the sample table. The load value (N) and the compression displacement (mm) at this time are measured. From the measured values obtained, the 10% K value at 25 ° C. can be determined by the following equation. As the above-mentioned micro compression tester, for example, "Micro compression tester MCT-W200" manufactured by Shimadzu Corporation, "Fisher Scope H-100" manufactured by Fisher, etc. may be used. The 10% K value of the conductive particles is preferably determined by arithmetically averaging the 10% K values of 50 conductive particles selected arbitrarily to calculate an average value.

10% K value (N / mm ² ) = (3/2 ^1/2 ) · F · S ⁻³ / ² · R ^−1/2
F: Load value when conductive particles undergo 10% compression deformation (N)
S: Compressive displacement (mm) when conductive particles are 10% compressively deformed
R: major diameter of conductive particles (mm)

  The above-mentioned K value expresses the hardness of conductive particles universally and quantitatively. By using the above-described K value, the hardness of the conductive particles can be quantitatively and uniquely represented.

  From the viewpoint of more effectively suppressing the occurrence of spring back and the viewpoint of enhancing the conduction reliability more effectively, the compression recovery rate when the conductive particles are deformed by 60% compression is preferably 3%. The content is more preferably 6% or more, preferably 15% or less, more preferably 12% or less, and still more preferably 10% or less.

  The compression recovery rate when 60% of the conductive particles are deformed by compression can be measured as follows.

  Scatter the conductive particles on the sample table. The conductive particles are in a stationary state by gravity. It is preferable to place the conductive particles in the most stabilized stationary state. In general, the longitudinal direction of the conductive particles is in the lateral direction. 60% of conductive particles in the vertical direction on the sample table at 25 ° C on the smooth indenter end face of a cylinder (diameter 100 μm, made of diamond) using a micro compression tester for one dispersed conductive particle Apply load (reverse load value) until compressive deformation occurs. After that, unloading is performed to the origin load value (0.40 mN). The load-compression displacement can be measured during this period, and the compression recovery rate when the conductive particles are deformed by 60% at 25 ° C. can be determined from the following equation. The loading speed is 0.33 mN / sec. As the above-mentioned micro compression tester, for example, "Micro compression tester MCT-W200" manufactured by Shimadzu Corporation, "Fisher Scope H-100" manufactured by Fisher, etc. may be used.

Compression recovery rate (%) = [L2 / L1] × 100
L1: Compressive displacement from the home load value to the reverse load value when applying a load L2: Unloaded displacement from the reverse load value to the home load value when releasing the load

Conductive part:
The metal for forming the said electroconductive part is not specifically limited. Examples of the metal include gold, silver, palladium, copper, platinum, zinc, iron, tin, lead, aluminum, cobalt, indium, nickel, chromium, titanium, antimony, bismuth, thallium, germanium, cadmium, silicon, tungsten, molybdenum And alloys thereof and the like. Moreover, tin-doped indium oxide (ITO), a solder, etc. are mentioned as said metal. Alloys containing tin, nickel, palladium, gold, copper or silver are preferred because the connection resistance between the electrodes can be further lowered. The metal may be an alloy containing tin, nickel, palladium, gold or copper, and may be nickel or palladium.

  Further, since the conduction reliability can be effectively improved, it is preferable that the conductive portion and the outer surface portion of the conductive portion include nickel. The content of nickel in 100% by weight of the conductive part containing nickel is preferably 10% by weight or more, more preferably 50% by weight or more, still more preferably 60% by weight or more, still more preferably 70% by weight or more, particularly preferably Is 90% by weight or more. The content of nickel in 100% by weight of the conductive part containing nickel may be 97% by weight or more, 97.5% by weight or more, or 98% by weight or more.

  Note that hydroxyl groups are often present on the surface of the conductive portion due to oxidation. In general, hydroxyl groups are present on the surface of a conductive portion formed of nickel by oxidation. An insulating substance can be disposed on the surface of the conductive portion having such a hydroxyl group (surface of the conductive particle) via a chemical bond.

  Like the conductive particles 1 and 31, the conductive portion may be formed by one layer. Like the conductive particles 21, the conductive portion may be formed of a plurality of layers. That is, the conductive portion may have a laminated structure of two or more layers. When the conductive portion is formed of a plurality of layers, the outermost layer is preferably a gold layer, a nickel layer, a palladium layer, a copper layer, a silver layer or an alloy layer containing tin, and it is a gold layer Is more preferred. When the outermost layer is these preferred conductive portions, the connection resistance between the electrodes can be further effectively reduced. In addition, when the outermost layer is a gold layer, the corrosion resistance can be more effectively enhanced. The alloy layer containing tin may be an alloy layer containing tin and silver.

  The method for forming the conductive portion on the surface of the base particle is not particularly limited. As the method of forming the conductive portion, a method by electroless plating, a method by electroplating, a method by physical vapor deposition, a method of coating metal powder or a paste containing metal powder and a binder on the surface of substrate particles, etc. Can be mentioned. Since the formation of the conductive part is simple, the method of forming the conductive part is preferably a method by electroless plating. Examples of the method by physical vapor deposition include methods such as vacuum deposition, ion plating and ion sputtering.

  The thickness of the conductive portion is preferably 0.005 μm or more, more preferably 0.01 μm or more, preferably 10 μm or less, more preferably 1 μm or less, and still more preferably 0.3 μm or less. When the thickness of the conductive portion is not less than the lower limit and not more than the upper limit, sufficient conductivity is obtained, and the conductive particles do not become too hard and the conductive particles are sufficiently conductive when connecting the electrodes. Deform.

  When the conductive part is formed of a plurality of layers, the thickness of the conductive part of the outermost layer is preferably 0.001 μm or more, more preferably 0.01 μm or more, preferably 0.5 μm or less, more preferably Is less than 0.1 μm. If the thickness of the conductive part of the outermost layer is not less than the lower limit and not more than the upper limit, the coating by the conductive part of the outermost layer becomes uniform, the corrosion resistance becomes sufficiently high, and the connection resistance between the electrodes is sufficient To lower. Also, when the outermost layer is a gold layer, the thinner the thickness of the gold layer, the lower the cost.

  The thickness of the conductive portion can be measured, for example, by observing the cross section of the conductive particle using a transmission electron microscope (TEM). With respect to the thickness of the conductive portion, it is preferable to calculate the average value of the thickness of five arbitrary conductive portions as the thickness of the conductive portion of one conductive particle, and the average value of the thickness of the entire conductive portion is one It is more preferable to calculate as the thickness of the conductive part. In the case of a plurality of conductive particles, the thickness of the conductive portion is preferably determined by calculating the average value of 10 arbitrary conductive particles.

Core substance:
The conductive particles preferably have a plurality of protrusions on the outer surface of the conductive portion. The conduction reliability between the electrodes can be further enhanced by the conductive particles having the plurality of protrusions on the outer surface of the conductive portion. An oxide film is often formed on the surface of the electrode connected by the conductive particles. Furthermore, an oxide film is often formed on the surface of the conductive portion of the conductive particle. By using the conductive particles having the projections, after the conductive particles are disposed between the electrodes, the oxide film is effectively eliminated by the projections by pressure bonding. Therefore, the electrodes and the conductive particles can be more reliably brought into contact, and the connection resistance between the electrodes can be further effectively lowered. Furthermore, when the conductive particles have an insulating substance on the surface, or when the conductive particles are dispersed in a binder resin and used as a conductive material, the protrusions of the conductive particles allow the conductive particles and the electrode to be separated. Insulating materials and binder resins are effectively eliminated. Therefore, the conduction reliability between the electrodes can be more effectively enhanced.

  By embedding the core substance in the conductive portion, a plurality of protrusions can be easily formed on the outer surface of the conductive portion. However, in order to form a projection on the surface of the conductive portion of the conductive particle, the core material may not necessarily be used.

  As a method of forming the above-mentioned protrusion, after making a core substance adhere to the surface of substrate particles, a method of forming a conductive part by electroless plating, and a conductive part was formed by electroless plating on the surface of substrate particles After that, a core material is attached, and a method of forming a conductive portion by electroless plating is further included. As another method of forming the above-mentioned protrusion, after forming the first conductive portion on the surface of the base particle, the core material is disposed on the first conductive portion, and then the second conductive portion is formed. And a method of adding a core substance in the middle of forming a conductive portion (such as a first conductive portion or a second conductive portion) on the surface of a substrate particle. In addition, in order to form projections, a conductive portion is formed on the substrate particles by electroless plating without using the above-mentioned core substance, and then plating is deposited in the form of projections on the surface of the conductive portion, and further electroless plating A method or the like may be used to form the conductive portion by

  As a method of arranging the core substance on the surface of the substrate particle, the core substance is added to the dispersion of the substrate particle, and the core substance is accumulated on the surface of the substrate particle by van der Waals force, A method of adhering, and a method of adding a core substance to a container containing substrate particles and adhering the core material to the surface of the substrate particles by mechanical action by rotation of the container etc. may be mentioned. In order to easily control the amount of the core substance to be attached, it is preferable to accumulate the core substance on the surface of the substrate particles in the dispersion and to make the core substance adhere.

  The material of the core material is not particularly limited. As a material of the said core substance, an electroconductive substance, a nonelectroconductive substance, etc. are mentioned. Examples of the conductive substance include metals, metal oxides, conductive nonmetals such as graphite, and conductive polymers. Examples of the conductive polymer include polyacetylene and the like. Examples of the nonconductive material include silica, alumina, titanium oxide, barium titanate and zirconia. Metals are preferred as they can increase conductivity and can effectively lower the connection resistance. The core material is preferably metal particles. As a metal which is a material of the said core substance, the metal quoted as a metal for forming the said electroconductive part can be used suitably.

Insulating material:
The conductive particles preferably further include an insulating material disposed on the surface of the conductive portion. In this case, when conductive particles are used for connection between electrodes, short circuit between adjacent electrodes can be further prevented. Specifically, when a plurality of conductive particles are in contact with each other, an insulating material is present between the plurality of electrodes, so that it is possible to prevent a short circuit between adjacent electrodes in the lateral direction rather than between the upper and lower electrodes. In addition, at the time of connection between the electrodes, by pressurizing the conductive particles with two electrodes, the insulating substance between the conductive portion of the conductive particles and the electrodes can be easily removed. When the conductive particle has a plurality of protrusions on the outer surface of the conductive part, the insulating material between the conductive part of the conductive particle and the electrode can be more easily removed.

  The insulating material is preferably insulating particles, because the insulating material can be more easily removed at the time of pressure bonding between the electrodes.

  Examples of materials for 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, etc. Can be mentioned. As the material of the insulating substance, only one type may be used, or two or more types may be used in combination.

  Examples of the polyolefin compound include polyethylene, ethylene-vinyl acetate copolymer, ethylene-acrylic acid ester copolymer and the like. Examples of the (meth) acrylate polymer include polymethyl (meth) acrylate, polydodecyl (meth) acrylate and polystearyl (meth) acrylate. Examples of the block polymer include polystyrene, styrene-acrylic acid ester copolymer, SB type styrene-butadiene block copolymer, SBS type styrene-butadiene block copolymer, and hydrogenated products thereof. Examples of the thermoplastic resin include vinyl polymers and vinyl copolymers. An epoxy resin, a phenol resin, a melamine resin etc. are mentioned as said thermosetting resin. Examples of crosslinking of the thermoplastic resin include introduction of polyethylene glycol methacrylate, alkoxylated trimethylolpropane methacrylate, alkoxylated pentaerythritol methacrylate, and the like. Examples of the water-soluble resin include polyvinyl alcohol, polyacrylic acid, polyacrylamide, polyvinyl pyrrolidone, polyethylene oxide and methyl cellulose. In addition, a chain transfer agent may be used to adjust the degree of polymerization. Examples of chain transfer agents include thiol and carbon tetrachloride.

  As a method of arranging an insulating material on the surface of the above-mentioned conductive part, a chemical method, a physical or mechanical method, etc. are mentioned. Examples of the chemical method include interfacial polymerization, suspension polymerization in the presence of particles, and emulsion polymerization. Examples of the physical or mechanical method include spray drying, hybridization, electrostatic deposition, spraying, dipping and vacuum deposition. It is preferable to dispose the insulating substance on the surface of the conductive part via a chemical bond because the insulating substance is difficult to be released.

  The outer surface of the conductive part and the surface of the insulating material may be coated with a compound having a reactive functional group. The outer surface of the conductive portion and the surface of the insulating material may not be directly chemically bonded, but may be indirectly chemically bonded by a compound having a reactive functional group. After introducing a carboxyl group to the outer surface of the conductive portion, the carboxyl group may be chemically bonded to a functional group on the surface of the insulating substance via a polymer electrolyte such as polyethyleneimine.

(Base particles)
The substrate particles according to the present invention are used to obtain conductive particles having a conductive portion. In the substrate particle according to the present invention, the 10% K value of the substrate particle is 2000 N / mm ² or less. In the substrate particle according to the present invention, when the area of the substrate particle and the area of the rectangle circumscribing the substrate particle are calculated by the electron microscope image or the optical microscope image of the substrate particle, the substrate The ratio of the area of the particles to the area of the rectangle circumscribing the base particle (the area of the substrate particle / the area of the rectangle circumscribing the base particle) is 0.80 or more.

  In the substrate particle according to the present invention, since the above-described configuration is provided, pressure bonding is performed at a low pressure when electrically connecting the electrodes using the substrate particle as conductive particles. Also, the connection resistance can be lowered.

  When the substrate particles according to the present invention are used as conductive particles, sufficient contact area between the conductive particles and the electrodes can be secured even when the electrodes are electrically connected at a relatively low pressure. And the connection resistance can be made sufficiently low.

  In addition, when the substrate particles according to the present invention are used as the conductive particles, there is no need to increase the pressure when electrically connecting the electrodes, so that scratching of the electrodes can be effectively suppressed. And the connection resistance can be made sufficiently low. In addition, when the substrate particles according to the present invention are used as conductive particles, it is not necessary to increase the pressure when electrically connecting the electrodes, so the compressed substrate particles have the original shape. The action to return is relatively difficult to work, and springback hardly occurs. When the substrate particles according to the present invention are used as the conductive particles, it is possible to effectively prevent the decrease in the contact area between the conductive particles and the electrode, and to sufficiently reduce the connection resistance. The conduction reliability can be effectively enhanced.

  The major diameter of the base particle is preferably 5 μm or more, more preferably 10 μm or more, preferably 50 μm or less, more preferably 40 μm or less, and still more preferably 35 μm or less. When the base particle is used as the conductive particle, if the major diameter of the base particle is not less than the lower limit and not more than the upper limit, the contact area between the conductive particle and the electrode becomes sufficiently large, so the connection resistance Can be lowered, and it becomes difficult to form aggregated conductive particles when forming the conductive portion. In addition, when the base particle is used as the conductive particle, if the major diameter of the base particle is the lower limit or more and the upper limit or less, the distance between the electrodes connected via the conductive particle is large. It does not become too much, and the conductive part becomes difficult to peel off from the surface of the base particle. Moreover, when the said base material particle is used as an electroconductive particle as long diameter of the said electroconductive particle is more than the said lower limit and below the said upper limit, electroconductive particle can be suitably used for the use of an electrically-conductive material .

  The major diameter of the base particle can be calculated, for example, by observing any base particle with an electron microscope. The major diameter of the above-mentioned base material particle is a size which the distance which connected two points of the perimeter of substrate particle by a straight line becomes the maximum.

  The major diameter of the substrate particles may be determined by observing 50 arbitrary substrate particles with an electron microscope or an optical microscope, and arithmetically averaging the major diameters of 50 arbitrary substrate particles to calculate an average value. preferable.

In the substrate particle according to the present invention, the 10% K value of the substrate particle is 2000 N / mm ² or less. 10% K value of the base particles is preferably 500 N / mm ² or more, more preferably 700 N / mm ² or more, preferably 1500 N / mm ² or less, and more preferably not more than 1300 N / mm ^2. When the base particle is used as a conductive particle, if the 10% K value of the base particle is not less than the lower limit and not more than the upper limit, generation of spring back can be more effectively suppressed. It is possible to improve the conduction reliability more effectively. In addition, when the base particle is used as the conductive particle, when the 10% K value of the base particle is not less than the lower limit and not more than the upper limit, the occurrence of the plating cracking of the conductive particle is further enhanced. This can be effectively suppressed, and the connection resistance can be further lowered.

  The 10% K value (the compression modulus when the base particles are compressed by 10%) of the base particles can be measured as follows.

  Place the substrate particles on the sample table. The substrate particles are in a stationary state by gravity. It is preferable to place the substrate particles in the most stabilized stationary state. In general, the longitudinal direction of the substrate particles is in the lateral direction. Using a micro compression tester, with a cylindrical (diameter 100 μm, made of diamond) smooth indenter end face, one substrate particle under the conditions of a compression speed of 0.3 mN / s and a maximum test load of 20 mN at 25 ° C Compress in the vertical direction on the sample table. The load value (N) and the compression displacement (mm) at this time are measured. From the measured values obtained, the 10% K value at 25 ° C. can be determined by the following equation. As the above-mentioned micro compression tester, for example, "Micro compression tester MCT-W200" manufactured by Shimadzu Corporation, "Fisher Scope H-100" manufactured by Fisher, etc. may be used. The 10% K value of the substrate particles is preferably determined by arithmetically averaging the 10% K values of 50 arbitrarily selected substrate particles to calculate an average value.

10% K value (N / mm ² ) = (3/2 ^1/2 ) · F · S ⁻³ / ² · R ^−1/2
F: Load value when substrate particles are 10% compressively deformed (N)
S: Compressive displacement (mm) when substrate particles are 10% compressively deformed
R: major diameter of base particle (mm)

  The above-mentioned K value expresses the hardness of substrate particles in a universal and quantitative manner. By using the above-described K value, the hardness of the base material particles can be quantitatively and uniquely represented.

  In the substrate particle according to the present invention, when the area of the substrate particle and the area of the rectangle circumscribing the substrate particle are calculated by the electron microscope image or the optical microscope image of the substrate particle, the substrate The ratio of the area of the particles to the area of the rectangle circumscribing the base particle (the area of the substrate particle / the area of the rectangle circumscribing the base particle) is 0.80 or more. As the above ratio (area of base particle / area of rectangle circumscribing base particle) is larger, the conductive particle has a shape closer to a rectangle. The aspect ratio of the substrate particles according to the invention is generally more than one. The aspect ratio (long diameter / short diameter) of the substrate particles according to the present invention may be 5 or less, or 3 or less.

  The rectangle circumscribing the substrate particle is drawn so that the area of the rectangle circumscribing the substrate particle is minimized.

  FIGS. 7A and 7B are schematic views for explaining the area of substrate particles and the area of a rectangle circumscribing the substrate particles in the substrate particles according to the present invention. In FIGS. 7A and 7B, an electron microscope image of the base material particle 11 obtained by observing the base material particle 11 described above with an electron microscope, and a rectangle 61 circumscribing the base material particle 11 and Is schematically shown.

  The area of the base particle is the area (S3) of the base particle 11 in FIG. 7A. The area of the rectangle circumscribing the base particle is the area (S4) of the rectangle 61 circumscribing the base particle 11 in FIG. 7B. The ratio of the area of the substrate particle to the area of the rectangle circumscribing the substrate particle is the ratio of the area (S3) of the substrate particle 11 to the substrate particle 11 in FIGS. 7 (a) and 7 (b). It is a ratio (S3 / S4) to the area (S4) of the circumscribed rectangle 61.

  From the viewpoint of effectively reducing the connection resistance, the ratio (area of base particle / area of rectangle circumscribed to base particle) in the base particle is preferably 0.82 or more, more preferably 0. 85 or more. The ratio (area of base particle / area of rectangle circumscribing base particle) in the base particle is preferably 1.0 or less, more preferably less than 1.0.

  In the observation, it is preferable that the base material particles do not reach the four apexes of the rectangle circumscribing the base material particles.

  The above ratio (area of base particle / area of rectangular circumscribed to base particle) in the base particle is obtained by observing 50 arbitrary base particles with an electron microscope or an optical microscope. It is preferable to obtain | require by calculating the average value by carrying out the arithmetic mean of the above-mentioned ratio (area of the base material particle / area of the rectangle circumscribed to base material particle).

  In the substrate particle according to the present invention, the above ratio (area of substrate particle / area of rectangle circumscribing substrate particle) is 0.80 or more. When the shape of the substrate particle is a true sphere, the above ratio (area of substrate particle / area of rectangle circumscribing substrate particle) is 0.785, and therefore the substrate particle according to the present invention The shape is not spherical. The shape of the substrate particles according to the present invention is not particularly limited as long as the above-described relationship is satisfied. The shape of the substrate particles according to the present invention may be columnar or may be bowl-like.

  When the substrate particles have a shape satisfying the above-mentioned relationship, the contact area between the conductive particles and the electrodes when electrically connecting the electrodes using the substrate particles as the conductive particles The pressure at the time of connection is uniformly applied to the entire conductive particles. As a result, when the substrate particles are used as the conductive particles, the occurrence of the plating cracking of the conductive particles can be more effectively suppressed, and the connection resistance can be further lowered. When the substrate particles are spherical, when the substrate particles are used as the conductive particles to electrically connect the electrodes, the contact area between the conductive particles and the electrodes is small, and the connection time is established. Pressure may be locally applied to the conductive particles. As a result, when the substrate particles are used as conductive particles, plating cracks of the conductive particles are likely to occur, and it may be difficult to reduce the connection resistance.

  The base particle satisfying the above ratio (area of base particle / area of rectangle circumscribed to base particle) adjusts the production conditions at the time of formation of the base particle, and the base formed with the production conditions It can be obtained by adjusting the 10% K value of particles. For example, at the time of formation of substrate particles, substrate particles having a predetermined shape can be obtained by applying a force to knead the substrate particles.

  From the viewpoint of more effectively suppressing the occurrence of spring back and the viewpoint of more effectively enhancing the conduction reliability, the compression recovery rate when the substrate particles are deformed by 60% compression is preferably 3%. The content is more preferably 6% or more, preferably 15% or less, more preferably 12% or less, and still more preferably 10% or less.

  The compression recovery rate when 60% of the base particles are deformed by compression can be measured as follows.

  Spray the base particles on the sample table. The substrate particles are in a stationary state by gravity. It is preferable to place the substrate particles in the most stabilized stationary state. In general, the longitudinal direction of the substrate particles is in the lateral direction. 60% of substrate particles in the vertical direction on the sample table at 25 ° C on the smooth indenter end face of a cylinder (diameter 100 μm, made of diamond) using a micro compression tester for one dispersed substrate particle Apply load (reverse load value) until compressive deformation occurs. After that, unloading is performed to the origin load value (0.40 mN). The load-compression displacement can be measured during this period, and the compression recovery rate when the substrate particles are deformed by 60% at 25 ° C. can be determined from the following equation. The loading speed is 0.33 mN / sec. As the above-mentioned micro compression tester, for example, "Micro compression tester MCT-W200" manufactured by Shimadzu Corporation, "Fisher Scope H-100" manufactured by Fisher, etc. may be used.

Compression recovery rate (%) = [L2 / L1] × 100
L1: Compressive displacement from the home load value to the reverse load value when applying a load L2: Unloaded displacement from the reverse load value to the home load value when releasing the load

  The substrate particles are used to obtain conductive particles. The above-mentioned substrate particles may be used for uses other than the use for obtaining conductive particles. The base particles may be used as a spacer. The substrate particles are preferably used as a spacer. The base particle is preferably used to obtain conductive particles having a conductive portion.

  Furthermore, the substrate particles are also suitably used as inorganic fillers, additives for toners, impact absorbers or vibration absorbers. For example, the above-mentioned substrate particles can be used as a substitute for rubber or spring.

(Other details of substrate particles)
The other details of the substrate particles will be described below. In the following description, "(meth) acrylic" means one or both of "acrylic" and "methacrylic", and "(meth) acrylate" means one or both of "acrylate" and "methacrylate". means.

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

  The base particle is more preferably a resin particle or an organic-inorganic hybrid particle, and particularly preferably a resin particle. By the use of these preferred substrate particles, the effects of the present invention can be exhibited more effectively, and conductive particles more suitable for electrical connection between electrodes can be obtained.

  When connecting the electrodes by the conductive particles using the base particles, the conductive particles are arranged between the electrodes, and then the conductive particles are compressed by pressure bonding. When the substrate particle is a resin particle, the conductive particle is easily deformed during the pressure bonding, and the contact area between the conductive particle and the electrode becomes large. Therefore, the connection resistance between the electrodes can be further lowered, and the conduction reliability between the electrodes can be further enhanced.

  Various resins are suitably used as the material of the resin particles. Examples of the material of the resin particles include polyolefin resins such as polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyvinylidene chloride, polyisobutylene and polybutadiene; acrylic resins such as polymethyl methacrylate and polymethyl acrylate; polyalkylene terephthalate, polycarbonate and polyamide Phenol formaldehyde resin, melamine formaldehyde resin, benzoguanamine formaldehyde resin, urea formaldehyde resin, phenol resin, melamine resin, melamine resin, benzoguanamine resin, urea resin, epoxy resin, unsaturated polyester resin, saturated polyester resin, polysulfone, polyphenylene oxide, polyacetal, polyimide, Polyamide imide, polyether ether ketone, polyethers Hong, and polymers such as obtained by a variety of polymerizable monomer having an ethylenically unsaturated group is polymerized with one or more thereof.

  Since resin particles having arbitrary compression physical properties suitable for the conductive material can be designed and synthesized, and the hardness of the substrate particles can be easily controlled to a suitable range, the material of the resin particles is ethylenic. It is preferable that it is a polymer obtained by polymerizing one or more kinds of polymerizable monomers having an unsaturated group.

  When the resin particle is obtained by polymerizing a polymerizable monomer having an ethylenically unsaturated group, as the polymerizable monomer having an ethylenically unsaturated group, a non-crosslinkable monomer may be used. And crosslinkable monomers.

  Examples of the non-crosslinkable monomers include styrene-based monomers such as styrene and α-methylstyrene; carboxyl-containing monomers such as (meth) acrylic acid, maleic acid and maleic anhydride; methyl ( Meta) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, cetyl (meth) acrylate, stearyl (meth) acrylate, cyclohexyl ( Alkyl (meth) acrylate compounds such as meta) acrylate and isobornyl (meth) acrylate; 2-hydroxyethyl (meth) acrylate, glycerol (meth) acrylate, polyoxyethylene (meth) acrylate, glycidyl (meth) acrylate and the like Element-containing (meth) acrylate compounds; nitrile-containing monomers such as (meth) acrylonitrile; acid vinyl ester compounds such as vinyl acetate, vinyl butyrate, vinyl laurate and vinyl stearate; ethylene, propylene, isoprene, butadiene and the like Unsaturated hydrocarbons; halogen-containing monomers such as trifluoromethyl (meth) acrylate, pentafluoroethyl (meth) acrylate, vinyl chloride, vinyl fluoride, chlorostyrene and the like can be mentioned.

  Examples of the crosslinkable monomer include, for example, tetramethylolmethane tetra (meth) acrylate, tetramethylolmethane tri (meth) acrylate, tetramethylolmethane di (meth) acrylate, trimethylolpropane tri (meth) acrylate, and dipentamer. Erythritol 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) Multifunctional (meth) acrylate compounds such as acrylate, (poly) tetramethylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate; triallyl (iso) cyan Silane-containing monomers such as triaryltrimellitate, divinylbenzene, diallyl phthalate, diallylacrylamide, diallyl ether, .gamma .- (meth) acryloxypropyltrimethoxysilane, trimethoxysilylstyrene, vinyltrimethoxysilane, etc. Can be mentioned.

  The said resin particle can be obtained by polymerizing the polymerizable monomer which has the said ethylenically unsaturated group by a well-known method. Examples of this method include a method of suspension polymerization in the presence of a radical polymerization initiator, and a method of swelling and polymerizing a monomer with a radical polymerization initiator using non-crosslinked seed particles.

  From the viewpoint of more effectively suppressing the occurrence of spring back and the viewpoint of enhancing the conduction reliability more effectively, it is preferable that the substrate particles contain an acrylic resin or a silicone resin. The base particle is preferably a particle containing an acrylic resin. The substrate particles are preferably particles containing a silicone resin.

  It is preferable that the material of the said acrylic resin is a (meth) acrylic compound. In the case where the above acrylic resin is obtained by polymerizing the above (meth) acrylic compound, as the above (meth) acrylic compound, a non-crosslinkable (meth) acrylic compound and a crosslinkable (meth) acrylic compound may be mentioned. Be

  Examples of the non-crosslinkable (meth) acrylic compounds include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate and lauryl (meth) acrylate Alkyl (meth) acrylate compounds such as cetyl (meth) acrylate, stearyl (meth) acrylate, cyclohexyl (meth) acrylate and isobornyl (meth) acrylate; 2-hydroxyethyl (meth) acrylate, glycerol (meth) acrylate, polyoxy Oxygen atom containing (meth) acrylate compounds, such as ethylene (meth) acrylate and glycidyl (meth) acrylate, etc. are mentioned. From the viewpoint of more effectively suppressing the occurrence of spring back and the viewpoint of enhancing the conduction reliability more effectively, the non-crosslinkable (meth) acrylic compound is cyclohexyl (meth) acrylate or isobornyl It is preferable that it is (meth) acrylate. The non-crosslinkable (meth) acrylic compounds may be used alone or in combination of two or more.

  Examples of the crosslinkable (meth) acrylic compound include tetramethylolmethane tetra (meth) acrylate, tetramethylolmethane tri (meth) acrylate, tetramethylolmethane di (meth) acrylate, trimethylolpropane tri (meth) acrylate, and dipentamer. Erythritol 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) Examples thereof include polyfunctional (meth) acrylate compounds such as acrylate, (poly) tetramethylene glycol di (meth) acrylate, and 1,4-butanediol di (meth) acrylate. From the viewpoint of more effectively suppressing the occurrence of spring back and the viewpoint of enhancing the conduction reliability more effectively, the crosslinkable (meth) acrylic compound is tetramethylolmethane tetra (meth) acrylate, or And tetramethylolmethane tri (meth) acrylate are preferred. Only one type of the crosslinkable (meth) acrylic compound may be used, or two or more types may be used in combination.

  The said acrylic resin can be obtained by polymerizing the said (meth) acrylic compound by a well-known method. Examples of this method include a method of suspension polymerization in the presence of a radical polymerization initiator, and a method of swelling and polymerizing a monomer with a radical polymerization initiator using non-crosslinked seed particles.

  The material of the silicone resin is either a silane compound having a radical polymerizable group and a silane compound having a hydrophobic group having 5 or more carbon atoms, or a silane having a radical polymerizable group and having a hydrophobic group having 5 or more carbon atoms It is preferably a compound or a silane compound having a radical polymerizable group at both ends. When these materials are reacted, a siloxane bond is formed. In the obtained silicone resin, a radically polymerizable group and a hydrophobic group having 5 or more carbon atoms generally remain. By using such a material, particles containing the silicone resin having a major diameter of 1 μm to 200 μm can be easily obtained, and the chemical resistance of the particles containing the silicone resin is enhanced, and moisture permeability is improved. It can be lowered.

  In the silane compound having a radical polymerizable group, the radical polymerizable group is preferably directly bonded to a silicon atom. Only one type of silane compound having a radical polymerizable group may be used, or two or more types may be used in combination.

  The silane compound having a radically polymerizable group is preferably an alkoxysilane compound. Examples of the silane compound having a radical polymerizable group include vinyltrimethoxysilane, vinyltriethoxysilane, dimethoxymethylvinylsilane, diethoxymethylvinylsilane, divinylmethoxyvinylsilane, divinylethoxyvinylsilane, divinyldimethoxysilane, divinyldiethoxysilane, and And 3-divinyl tetramethyl disiloxane and the like.

  In the silane compound having a 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. Only one type of silane compound having a hydrophobic group having 5 or more carbon atoms may be used, or two or more types may be used in combination.

  The silane compound having a hydrophobic group having 5 or more carbon atoms is preferably an alkoxysilane compound. The above-mentioned silane compounds 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-tetrapenyltrisiloxane, 1,1,3,5,5-pentaphenyl-1,3,5-trimethyltrisiloxane, hexaphenylcyclotrisiloxane, phenyl Examples include tris (trimethylsiloxy) silane, octaphenyl cyclotetrasiloxane and the like.

  In the silane compound having a radical polymerizable group and a hydrophobic group having 5 or more carbon atoms, the radical polymerizable group is preferably directly bonded to a silicon atom, and the hydrophobic group having 5 or more carbon atoms is preferably a silicon atom Preferably, they are directly bonded. Only one type of silane compound having a radical polymerizable group and a hydrophobic group having 5 or more carbon atoms may be used, or two or more types may be used in combination.

  As the silane compound having a radical polymerizable group and having a hydrophobic group having 5 or more carbon atoms, phenylvinyldimethoxysilane, phenylvinyldiethoxysilane, phenylmethylvinylmethoxysilane, phenylmethylvinylethoxysilane, diphenylvinylmethoxysilane And diphenylvinylethoxysilane, phenyldivinylmethoxysilane, phenyldivinylethoxysilane, 1,1,3,3-tetraphenyl-1,3-divinyldisiloxane and the like.

  When a silane compound having a radical polymerizable group and a silane compound having a hydrophobic group having 5 or more carbon atoms are used to obtain particles containing the silicone resin, the hydrophobic group having 5 or more carbon atoms is provided. The ratio of the weight of the silane compound to the weight of the silane compound having a radically polymerizable group is preferably 1 or more, more preferably 5 or more. When a silane compound having a radical polymerizable group and a silane compound having a hydrophobic group having 5 or more carbon atoms are used to obtain particles containing the silicone resin, the hydrophobic group having 5 or more carbon atoms is provided. The ratio of the weight of the silane compound to the weight of the silane compound having a radically polymerizable group is preferably 20 or less, more preferably 15 or less.

  The ratio of the number of hydrophobic groups having 5 or more carbon atoms to the number of radically polymerizable groups is preferably 0.5 or more, more preferably 1 or more in the entire silane compound for obtaining particles containing the silicone resin. Preferably it is 20 or less, More preferably, it is 15 or less.

  From the viewpoint of more effectively suppressing the occurrence of spring back and the viewpoint of enhancing the conduction reliability more effectively, the particle containing the silicone resin is dimethyl having two methyl groups bonded to one silicon atom. It is preferable to have a siloxane skeleton. From the viewpoint of more effectively suppressing the occurrence of spring back and the viewpoint of enhancing the conduction reliability more effectively, the material of the silicone resin is a silane compound in which two methyl groups are bonded to one silicon atom. Is preferred.

  From the viewpoint of more effectively suppressing the occurrence of spring back and the viewpoint of enhancing the conduction reliability more effectively, the particles containing the silicone resin are reacted with the above-mentioned silane compound using a radical polymerization initiator. Preferably, a siloxane bond is formed. Generally, when synthesizing particles containing the above silicone resin by polycondensation using an acid or base catalyst, it is difficult to obtain particles containing a silicone resin having a long diameter of 10 μm or more and 500 μm or less, and have a long diameter of 50 μm or less It is particularly difficult to obtain particles comprising a silicone resin. On the other hand, by using a radical polymerization initiator and the silane compound having the above structure, particles containing a silicone resin having a long diameter of 1 μm to 500 μm can be obtained, and particles containing a silicone resin having a long diameter of 10 μm or more And particles containing a silicone resin having a major diameter of 50 μm or less can also be obtained.

  In order to obtain particles containing the silicone resin, a silane compound having a hydrogen atom bonded to a silicon atom may not be used. In this case, the silane compound can be polymerized using a radical polymerization initiator without using a metal catalyst. As a result, the particles containing the silicone resin can be prevented from containing the metal catalyst, the content of the metal catalyst in the particles containing the silicone resin can be reduced, and the occurrence of springback is further enhanced. And conduction reliability can be more effectively enhanced.

  As a specific production method of the particles containing the silicone resin, the polymerization reaction of the silane compound is carried out by a suspension polymerization method, a dispersion polymerization method, a mini emulsion polymerization method, an emulsion polymerization method or the like to produce particles containing a silicone resin. There is a way to do it. After the polymerization of the silane compound is advanced to obtain an oligomer, the polymerization reaction of the silane compound which is a polymer (oligomer etc.) is carried out by a suspension polymerization method, a dispersion polymerization method, a mini emulsion polymerization method, or an emulsion polymerization method, Particles comprising a silicone resin may be made. For example, a silane compound having a vinyl group may be polymerized to obtain a silane compound having a vinyl group bonded to a silicon atom at an end. The silane compound having a phenyl group may be polymerized to obtain a silane compound having a phenyl group bonded to a silicon atom in a side chain as a polymer (oligomer or the like). A polymer (such as an oligomer) obtained by polymerizing a silane compound having a vinyl group and a silane compound having a phenyl group is a phenyl group having a vinyl group bonded to a silicon atom at its end and bonded to a silicon atom in a side chain You may obtain the silane compound which has these.

  The conductive particle may have a nonconductive portion between the base particle and the conductive portion. The non-conductive portion is preferably disposed on the surface of the base particle. The non-conductive portion preferably covers the surface of the base particle. In the present invention, when the non-conductive portion is disposed on the surface of the base particle, the conductive portion is disposed on the surface of the base particle via the non-conductive portion. . The non-conductive portion may cover a part of the surface of the base particle, or may cover the entire surface of the base particle. The non-conductive portion may have a single layer structure or a multilayer structure of two or more layers.

(Conductive material)
The conductive material according to the present invention includes conductive particles and a binder resin. The conductive particles are the above-described conductive particles, or the conductive particles provided with the above-described base particles and a conductive portion disposed on the surface of the base particles. The conductive particles are preferably dispersed in a binder resin and used, and preferably dispersed in a binder resin and used as a conductive material. The conductive material is preferably an anisotropic conductive material. The conductive material is preferably used for electrical connection between the electrodes. The conductive material is preferably a conductive material for circuit connection.

  The conductive material may include conductive particles (second conductive particles) other than the conductive particles according to the present invention. The second conductive particles may be spherical. The conductive material may include second conductive particles as a component different from the conductive particles. The second conductive particles are different from the conductive particles described above. With the second conductive particle, the area of the second conductive particle and the area of a rectangle circumscribing the second conductive particle were calculated by the electron microscope image or the optical microscope image of the second conductive particle. Sometimes, it means conductive particles in which the ratio of the area of the second conductive particles to the area of the rectangle circumscribing the second conductive particles is 0.785 or more and less than 0.80.

  In the conductive material, the content of the second conductive particles is not particularly limited. In the above conductive material, when the content of the second conductive particle is larger than the content of the conductive particle, when the electrodes are connected using the conductive material, the entire conductive particle is connected between the electrodes It is easy to be placed evenly. In the conductive material, when the content of the conductive particles is larger than the content of the second conductive particles, the connection resistance is further increased when the electrodes are connected using the conductive material. It can be lowered.

  The binder resin is not particularly limited. A well-known insulating resin is used as said binder resin. The binder resin preferably contains a thermoplastic component (thermoplastic compound) or a curable component, and more preferably contains a curable component. As said curable component, a photocurable component and a thermosetting component are mentioned. It is preferable that the said photocurable component contains a photocurable compound and a photoinitiator. It is preferable that the said thermosetting component contains a thermosetting compound and a thermosetting agent.

  As said binder resin, a vinyl resin, a thermoplastic resin, curable resin, a thermoplastic block copolymer, an elastomer, etc. are mentioned. The binder resin may be used alone or in combination of two or more.

  Examples of the vinyl resin include vinyl acetate resin, acrylic resin and styrene resin. Examples of the thermoplastic resin include polyolefin resins, ethylene-vinyl acetate copolymers, and polyamide resins. As said curable resin, an epoxy resin, a urethane resin, a polyimide resin, unsaturated polyester resin, etc. are mentioned. The curable resin may be a room temperature curable resin, a thermosetting resin, a photocurable resin, or a moisture curable resin. The curable resin may be used in combination with a curing agent. Examples of the thermoplastic block copolymer include styrene-butadiene-styrene block copolymer, styrene-isoprene-styrene block copolymer, hydrogenated product of styrene-butadiene-styrene block copolymer, and styrene-isoprene-styrene The hydrogenated substance of a block copolymer etc. are mentioned. Examples of the elastomer include styrene-butadiene copolymer rubber and acrylonitrile-styrene block copolymer rubber.

  In addition to the conductive particles and the binder resin, the conductive material is, for example, a filler, an extender, a softener, a plasticizer, a polymerization catalyst, a curing catalyst, a colorant, an antioxidant, a heat stabilizer, and light stability. Various additives such as agents, UV absorbers, lubricants, antistatic agents and flame retardants may be included.

  The method of dispersing the conductive particles in the binder resin can be a conventionally known dispersion method, and is not particularly limited. The following method is mentioned as a method of disperse | distributing the said electroconductive particle in the said binder resin. A method in which the conductive particles are added to the binder resin and then kneaded and dispersed by a planetary mixer or the like. A method of uniformly dispersing the conductive particles in water or an organic solvent using a homogenizer or the like, and then adding the conductive particles in the binder resin, and kneading and dispersing the mixture using a planetary mixer or the like. Furthermore, as another method of dispersing the conductive particles in the binder resin, after diluting the binder resin with water, an organic solvent or the like, the conductive particles are added and kneaded by a planetary mixer or the like. The method of disperse | distributing etc. are mentioned.

  The said conductive material can be used as a conductive paste, a conductive film, etc. When the conductive material is a conductive film, a film not containing conductive particles may be laminated on a conductive film containing conductive particles. The conductive paste is preferably an anisotropic conductive paste. The conductive film is preferably an anisotropic conductive film.

  The content of the binder resin is preferably 10% by weight or more, more preferably 30% by weight or more, still more preferably 50% by weight or more, particularly preferably 70% by weight or more, based on 100% by weight of the conductive material. Is 99.99% by weight or less, more preferably 99.9% by weight or less. When the content of the binder resin is the lower limit or more and the upper limit or less, the conductive particles are efficiently disposed between the electrodes, and the connection reliability of the connection target member connected by the conductive material is further enhanced. .

  The content of the conductive particles is preferably 0.01% by weight or more, more preferably 0.1% by weight or more, and preferably 80% by weight or less, more preferably 60% by weight in 100% by weight of the conductive material. % Or less, more preferably 40% by weight or less, particularly preferably 20% by weight or less, and most preferably 10% by weight or less. When the content of the conductive particles is not less than the lower limit and not more than the upper limit, the conduction reliability between the electrodes is further enhanced.

  When the conductive material according to the present invention and the second conductive particle according to the present invention are included in the conductive material, the content of the conductive particle according to the present invention relative to the content of the second conductive particle according to the present invention The ratio may be 0.01 or more, 0.05 or more, or 0.1 or more. When the conductive material according to the present invention and the second conductive particle according to the present invention are included in the conductive material, the content of the conductive particle according to the present invention relative to the content of the second conductive particle according to the present invention The ratio may be 0.99 or less, 0.95 or less, or 0.9 or less.

(Connected structure)
A connection structure can be obtained by connecting the connection target member using the conductive particles described above or using the conductive material containing the conductive particles described above and the binder resin.

  A connection structure according to the present invention includes a first connection target member having a first electrode on the surface, a second connection target member having a second electrode on the surface, the first connection target member, and the above. And a connection portion connecting the second connection target member. The material of the connection portion is conductive particles, or a conductive material containing conductive particles and a binder resin. The conductive particles are the above-described conductive particles or the above-described base particles, and the conductive particles provided with the conductive portion disposed on the surface of the base particles. It is preferable that the material of the said connection part contains the electroconductive particle mentioned above. It is preferable that the connection portion is a connection structure formed of the conductive particles or formed of the conductive material.

  When the conductive particles are used alone, the connection portion itself is a conductive particle. That is, the first connection target member and the second connection target member are connected by the conductive particles. The conductive material used to obtain the connection structure is preferably an anisotropic conductive material. It is preferable that the first electrode and the second electrode be electrically connected by the conductive particles.

  FIG. 5 is a cross-sectional view showing an example of a connection structure using the conductive particles 1 shown in FIG.

  The connection structure 41 shown in FIG. 5 is a connection in which the first connection target member 42, the second connection target member 43, the first connection target member 42, and the second connection target member 43 are connected. And a unit 44. The connection portion 44 is formed of a conductive material including the conductive particles 1 and a binder resin. In FIG. 5, for convenience of illustration, the conductive particles 1 are shown schematically. Instead of the conductive particles 1, other conductive particles such as conductive particles 21 and 31 may be used.

  The first connection target member 42 has a plurality of first electrodes 42 a on the surface (upper surface). The second connection target member 43 has a plurality of second electrodes 43a on the surface (lower surface). The first electrode 42 a and the second electrode 43 a are electrically connected by one or more conductive particles 1. Therefore, the first connection target member 42 and the second connection target member 43 are electrically connected by the conductive particles 1.

The manufacturing method of the said connection structure is not specifically limited. As an example of a method of manufacturing a connection structure, a method of disposing the conductive material between a first connection target member and a second connection target member, obtaining a laminate, and then heating and pressing the laminate. Etc. The pressure of the said pressurization is about 9.8 * 10 < ⁴ > Pa-4.9 * 10 < ⁶ > Pa. The temperature of the said heating is about 120 degreeC-220 degreeC. The pressure of the said pressurization for connecting the electrode of a flexible printed circuit board, the electrode arrange | positioned on a resin film, and the electrode of a touch panel is about 9.8 * 10 < ⁴ > Pa-1.0 * 10 < ⁶ > Pa.

  Specific examples of the connection target member include electronic components such as a semiconductor chip, a capacitor, and a diode, and electronic components such as a printed circuit board, a flexible printed circuit, a circuit board such as a glass epoxy substrate and a glass substrate, and the like. The connection target member is preferably an electronic component. It is preferable that at least one of the first connection target member and the second connection target member is a semiconductor wafer or a semiconductor chip. The connection structure is preferably a semiconductor device.

  The conductive material is preferably a conductive material for connecting an electronic component. The conductive paste is a paste-like conductive material, and is preferably applied on the connection target member in a paste-like state.

  The conductive particles and the conductive material are also suitably used in a touch panel. Therefore, the connection target member is preferably a flexible substrate or a connection target member in which an electrode is disposed on the surface of a resin film. It is preferable that the said connection object member is a flexible substrate, and it is preferable that it is a connection object member by which the electrode was arrange | positioned on the surface of a resin film. When the flexible substrate is a flexible printed substrate or the like, the flexible substrate generally has an electrode on the surface.

  As an electrode provided in the said connection object member, metal electrodes, such as a gold electrode, a nickel electrode, a tin electrode, an aluminum electrode, a silver electrode, a SUS electrode, a copper electrode, a molybdenum electrode, a tungsten electrode, etc. are mentioned. When the connection target member is a flexible printed board, the electrode is preferably a gold electrode, a nickel electrode, a tin electrode or a copper electrode. When the connection target member is a glass substrate, the electrode is preferably an aluminum electrode, a copper electrode, a molybdenum electrode or a tungsten electrode. In addition, when the said electrode is an aluminum electrode, the electrode formed only with aluminum may be sufficient, and the electrode by which the aluminum layer was laminated | stacked on the surface of a metal oxide layer may be sufficient. As a material of the said metal oxide layer, the indium oxide in which the trivalent metal element was doped, the zinc oxide in which the trivalent metal element was doped, etc. are mentioned. Sn, Al, Ga, etc. are mentioned as said trivalent metal element.

  Hereinafter, the present invention will be specifically described by way of examples and comparative examples. The invention is not limited to the following examples.

Example 1
(1) Preparation of Base Particle As a seed particle, polystyrene particles having an average particle diameter of 6.0 μm were prepared. A mixed solution was prepared by mixing 5.0 parts by weight of the polystyrene particles, 900 parts by weight of ion exchanged water, and 170 parts by weight of a 5% by weight aqueous solution of polyvinyl alcohol. The above mixed solution was dispersed by ultrasonication, and then placed in a separable flask and uniformly stirred.

  Next, 10 parts by weight of polytetramethylene glycol diacrylate, 10 parts by weight of cyclohexyl methacrylate, and 80 parts by weight of isobornyl acrylate were mixed to obtain a mixture. To the obtained mixture, 6.0 parts by weight of benzoyl peroxide (“Nyper BW” manufactured by NOF Corporation) was added, and further, 1000 parts by weight of ion exchanged water was added to prepare an emulsion.

  The above emulsion was further added to the above mixture in the separable flask and stirred for 16 hours to allow the seed particles to absorb the monomer, thereby obtaining a suspension containing the seed particles in which the monomer was swollen.

  Thereafter, 510 parts by weight of a 5% by weight aqueous solution of polyvinyl alcohol is added, heating is started, and the rotor at the bottom of the separable flask is reacted with stirring at 300 rpm for 10 hours at 85 ° C. The base particles were washed with water, methanol and acetone.

(2) Preparation of Conductive Particles The obtained base material particles were washed and classified and then dried. Thereafter, a nickel layer was formed on the surface of the obtained base material particles by electroless plating to prepare conductive particles. The thickness of the nickel layer was 0.1 μm.

(3) Production of Conductive Material (Anisotropic Conductive Paste) In order to produce a conductive material (anisotropic conductive paste), the following materials were prepared.

(Material of conductive material (anisotropic conductive paste))
Thermosetting compound A: epoxy compound (manufactured by Nagase ChemteX "EP-3300P")
Thermosetting Compound B: Epoxy Compound ("EPICLON HP-4032D" manufactured by DIC Corporation)
Thermosetting compound C: Epoxy compound ("Epogorsey PT", polytetramethylene glycol diglycidyl ether, manufactured by Yokkaichi Gosei Co., Ltd.)
Thermosetting agent: Thermal cation generator (Sanaid "SI-60" manufactured by Sanshin Chemical Co., Ltd.)
Filler: silica (average particle size 0.25 μm)
A conductive material (anisotropic conductive paste) was produced as follows.

(Method of producing conductive material (anisotropic conductive paste))
10 parts by weight of a thermosetting compound A, 10 parts by weight of a thermosetting compound B, 15 parts by weight of a thermosetting compound C, 5 parts by weight of a thermosetting agent, and 20 parts by weight of a filler were blended to obtain a compound. Furthermore, after adding the obtained conductive particles so that the content in 100% by weight of the composition is 10% by weight, the conductive material (anisotropic material (anisotropic material) is obtained by stirring for 5 minutes at 2000 rpm using a planetary stirrer. Conductive paste) was obtained.

(4) Preparation of Connection Structure A glass substrate having an aluminum electrode pattern with L / S of 20 μm / 20 μm on the top surface was prepared as a first connection target member. In addition, as a second connection target member, a semiconductor chip having a gold electrode pattern (gold electrode thickness 20 μm) of 20 μm / 20 μm at L / S on the lower surface was prepared.

  A conductive material (anisotropic conductive paste) immediately after preparation was coated on the upper surface of the glass substrate to a thickness of 30 μm to form a conductive material (anisotropic conductive paste) layer. Next, the semiconductor chip was laminated on the upper surface of the conductive material (anisotropic conductive paste) layer so that the electrodes face each other. Thereafter, while adjusting the temperature of the head so that the temperature of the conductive material (anisotropic conductive paste) layer becomes 170 ° C., the pressure heating head is placed on the upper surface of the semiconductor chip, and the conductive material (anisotropic conductive paste) The layer was cured under conditions of 170 ° C., 1.0 MPa, and 15 seconds to obtain a connection structure.

(Example 2)
In the same manner as in Example 1 except that the rotational speed of the stirrer was changed to a half rotational speed (150 rpm) when producing the substrate particles, the substrate particles, the conductive particles, the conductive material, and the connecting structure I got

(Example 3)
A substrate particle, a conductive particle, a conductive material, and in the same manner as in Example 1 except that polytetramethylene glycol diacrylate is changed to 1,4-butanediol diacrylate when producing the substrate particle I got a connection structure.

(Example 4)
The substrate particles, the conductive particles, the conductive material, and the connection are prepared in the same manner as in Example 1 except that the rotation speed of the stirrer is changed to a rotation speed (100 rpm) of 1/3 when producing the substrate particles. I got a structure.

(Example 5)
When producing the conductive particles, conductive particles, a conductive material, and a connection structure were obtained in the same manner as in Example 1 except that a gold layer (0.02 μm) was formed on the surface of the nickel layer.

(Example 6)
When producing a conductive particle, conductive particles, a conductive material, and a connection structure were obtained in the same manner as in Example 1 except that a palladium layer (0.02 μm) was formed on the surface of the nickel layer.

(Example 7)
When producing the conductive particles, conductive particles, a conductive material and a connection structure were obtained in the same manner as in Example 1 except that a copper layer (0.1 μm) was formed on the surface of the nickel layer.

(Example 8)
When producing the conductive particles, conductive particles, a conductive material, and a connection structure were obtained in the same manner as in Example 1 except that a silver layer (0.1 μm) was formed on the surface of the nickel layer.

(Example 9)
When producing conductive particles, conductive particles, a conductive material, and a connection structure were obtained in the same manner as in Example 1 except that a solder layer (0.3 μm) was formed on the surface of the nickel layer.

(Example 10)
When producing a conductive particle, a nickel particle slurry (average particle diameter 150 nm) is adsorbed on the surface of a substrate particle, then a nickel layer is formed, and a plurality of protrusions are formed on the outer surface of a conductive portion. In the same manner as in Example 1, conductive particles, a conductive material, and a connection structure were obtained.

(Example 11)
When preparing the conductive particles, after the alumina particle slurry (average particle diameter 150 nm) is adsorbed on the surface of the base particle, a nickel layer is formed, and a plurality of protrusions are formed on the outer surface of the conductive portion. In the same manner as in Example 1, conductive particles, a conductive material, and a connection structure were obtained.

(Example 12)
When producing a conductive particle, a nickel layer is formed after a titanium oxide particle slurry (average particle diameter 150 nm) is adsorbed on the surface of a substrate particle, and a plurality of protrusions are formed on the outer surface of a conductive portion In the same manner as in Example 1, conductive particles, a conductive material and a connection structure were obtained.

(Comparative example 1)
When producing the substrate particles, the substrate particles, the conductive particles, the conductive material, and the connection are the same as in Example 1 except that the stirring is performed with the paddle in the center of the separable flask without stirring with the stirrer. I got a structure.

(Comparative example 2)
When preparing the substrate particles, the blending amount of polytetramethylene glycol diacrylate is changed from 10 parts by weight to 3 parts by weight, and the blending amount of cyclohexyl methacrylate is changed from 10 parts by weight to 3 parts by weight, The compounding amount of the nyl acrylate was changed from 80 parts by weight to 94 parts by weight. A substrate particle, a conductive particle, a conductive material, and a connection structure were obtained in the same manner as in Example 1 except for the above changes.

(Evaluation)
(1) Long Diameters of Base Particles and Long Diameters of Conductive Particles The obtained base particles and conductive particles were observed with an electron microscope to calculate the long diameters of the base particles and the conductive particles. The major diameters of the base particles and the conductive particles are obtained by observing 50 arbitrary base particles and 50 optional conductive particles with an electron microscope, and 50 long diameters of any base particles and optional conductive particles 50 It calculated | required by computing the average value arithmetically averaging the length diameter of this.

(2) 10% K value of substrate particles and 10% K value of conductive particles About the obtained substrate particles and conductive particles, 10% K value of substrate particles and 10% K value of conductive particles It measured using the micro compression tester (Fisher's "Fisher scope H-100") by the method mentioned above.

(3) Shape of Base Material Particles and Shape of Conductive Particles The obtained base material particles were observed with an electron microscope to calculate the area of the base material particles and the rectangular area circumscribed to the base material particles. From the measurement results, the ratio of the area of the substrate particles to the area of the rectangle circumscribing the substrate particles (the area of the substrate particles / the area of the rectangle circumscribing the substrate particles) was calculated. The above ratio (area of base particle / area of rectangular circumscribed to base particle) in the obtained base particle is obtained by observing 50 arbitrary base particles with an electron microscope, and 50 arbitrary base particles The above ratio (area of base particle / area of rectangle circumscribed to base particle) is arithmetically averaged to obtain an average value. From the above ratio (area of base particle / area of rectangle circumscribed to base particle), the shape of the base particle was determined according to the following criteria.

[Criteria for determining the shape of substrate particles]
○: Ratio of area of substrate particle to area of rectangle circumscribing substrate particle (area of substrate particle / area of rectangle circumscribing substrate particle) is 0.80 or more. ×: area of substrate particle The ratio to the area of the rectangle circumscribing the substrate particles (the area of the substrate particles / the area of the rectangle circumscribing the substrate particles) is less than 0.80

  The area of the conductive particles and the area of a rectangle circumscribing the conductive particles were calculated by observing the obtained conductive particles with an electron microscope. From the measurement results, the ratio of the area of the conductive particles to the area of the rectangle circumscribing the conductive particles (area of the conductive particles / area of the rectangle circumscribing the conductive particles) was calculated. The above ratio (area of conductive particle / area of rectangle circumscribing conductive particle) in the obtained conductive particles is obtained by observing 50 of any conductive particles with an electron microscope, and 50 of any conductive particles The ratio (area of conductive particle / area of rectangle circumscribing conductive particle) is arithmetically averaged to obtain an average value. From the above ratio (area of conductive particle / area of rectangle circumscribing conductive particle), the shape of the conductive particle was determined according to the following criteria.

[Criteria for judging the shape of conductive particles]
○: The ratio of the area of the conductive particle to the area of the rectangle circumscribing the conductive particle (area of the conductive particle / area of the rectangle circumscribing the conductive particle) is 0.80 or more. ×: area of the conductive particle And the ratio of the area of the rectangle circumscribing the conductive particle (the area of the conductive particle / the area of the rectangle circumscribing the conductive particle) is less than 0.80.

(4) Compression recovery rate when 60% compression deformation of base material particles and compression recovery rate when 60% compression deformation of conductive particles are obtained For the obtained base particles and conductive particles, base material particles are used. The compression recovery rate at 60% compression deformation and the compression recovery rate at 60% compression deformation of the conductive particles were measured by the method described above.

(5) Initial Connection Resistance The connection resistance A between opposing electrodes of the obtained connection structure was measured by the four-terminal method. From the relationship of voltage = current × resistance, the connection resistance A can be obtained by measuring the voltage when a constant current flows. The initial connection resistance was determined from the connection resistance A based on the following criteria.

[Criteria for initial connection resistance]
○: Connection resistance A is 2Ω or less ○: Connection resistance A is more than 2Ω and 3Ω or less Δ: Connection resistance A is more than 3Ω and 5Ω or less ×: Connection resistance A is more than 5Ω

(6) Connection resistance after high temperature and high humidity (conduction reliability)
The connection structure after evaluation of the connection resistance in the above (5) initial stage was left for 500 hours at 85 ° C. and 85% humidity. In the connection structure after being left for 500 hours, the connection resistance B between the opposing electrodes was measured by the four-terminal method. The connection resistance (conduction reliability) after being left at high temperature and high humidity was determined from the connection resistances A and B according to the following criteria.

[Judgment criteria of connection resistance (conduction reliability) after high temperature and high humidity]
○: connection resistance B is less than 1.25 times connection resistance A ○: connection resistance B is 1.25 times or more and less than 1.5 times connection resistance A :: connection resistance B is 1. of connection resistance A 5 times or more and 2 times or less Δ: connection resistance B is 2 times or more and 5 times or less of connection resistance A ×: connection resistance B is 5 times or more of connection resistance A

(7) Plating crack By the scanning electron microscope, in the electroconductive particle in the connection part of the obtained bonded structure, it was observed whether the plating crack generate | occur | produced. The plating cracking was determined according to the following criteria.

[Determining criteria for plating cracks]
○: no plating cracking occurred ×: plating cracking occurred

  The results are shown in Table 1 below.

DESCRIPTION OF SYMBOLS 1 ... Conductive particle 1X ... Conductive particle 2 ... Conductive part 2X ... Conductive part 11 ... Base material particle 11X ... Base material particle 21 ... Conductive particle 22 ... Conductive part 22A ... 1st conductive part 22B ... 2nd conductive Part 31 ... conductive particle 31 a ... projection 32 ... conductive part 32 a ... projection 33 ... core material 34 ... insulating material 41 ... connection structure 42 ... first connection target member 42 a ... first electrode 43 ... second connection Target member 43a ... 2nd electrode 44 ... connection part

Claims (15)

Substrate particles,
A conductive particle provided on the surface of the substrate particle;
When the area of the conductive particle and the area of a rectangle circumscribing the conductive particle are calculated by an electron microscope image or an optical microscope image of the conductive particle, the conductive particle of the area of the conductive particle Conductive particles, wherein the ratio to the area of the rectangle circumscribing the is 0.80 or more. The electroconductive particle of Claim 1 whose 10% K value is 3200 N / mm < ² > or less.   The conductive particle according to claim 1 or 2, wherein a compression recovery rate at a time of 60% compression deformation is 15% or less.   The electroconductive particle of any one of Claims 1-3 whose said base material particle is a resin particle.   The conductive particle according to claim 4, wherein the resin particle comprises an acrylic resin or a silicone resin.   The conductive particle according to any one of claims 1 to 5, further comprising an insulating material disposed on the outer surface of the conductive portion.   The electroconductive particle of any one of Claims 1-6 which has a processus | protrusion in the outer surface of the said electroconductive part. A substrate particle used to obtain conductive particles having a conductive portion,
The 10% K value of the base particle is 2000 N / mm ² or less,
When the area of the substrate particle and the area of a rectangle circumscribing the substrate particle are calculated by an electron microscope image or an optical microscope image of the substrate particle, the substrate particle of the area of the substrate particle Substrate particles whose ratio to the area of a rectangle circumscribed by is 0.80 or more.   The substrate particles according to claim 8, wherein the compression recovery rate when compressed 60% is 15% or less.   The base material particle of Claim 8 or 9 which is a resin particle.   The base material particle of Claim 10 in which the said resin particle contains an acrylic resin or a silicone resin. Containing conductive particles and a binder resin,
A conductive material, wherein the conductive particle is the conductive particle according to any one of claims 1 to 7. Containing conductive particles and a binder resin,
A conductive material, wherein the conductive particle is a conductive particle including the substrate particle according to any one of claims 8 to 11 and a conductive portion disposed on the surface of the substrate particle. A first connection target member having a first electrode on the surface;
A second connection target member having a second electrode on its surface;
A connecting portion connecting the first connection target member and the second connection target member;
The material of the connection portion is conductive particles, or a conductive material containing the conductive particles and a binder resin,
The said electroconductive particle is an electroconductive particle of any one of Claims 1-7,
The connection structure which the said 1st electrode and the said 2nd electrode are electrically connected by the said electroconductive particle. A first connection target member having a first electrode on the surface;
A second connection target member having a second electrode on its surface;
A connecting portion connecting the first connection target member and the second connection target member;
The material of the connection portion is conductive particles, or a conductive material containing the conductive particles and a binder resin,
The conductive particle is a conductive particle provided with the substrate particle according to any one of claims 8 to 11 and a conductive portion disposed on the surface of the substrate particle,
The connection structure which the said 1st electrode and the said 2nd electrode are electrically connected by the said electroconductive particle.

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