JP2016085988A - Insulative particle-adhered conductive particle and production method thereof, conductive material, and connection structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an insulative particle-adhered conductive particle that can increase the conduction reliability and insulation reliability after conductive connection.SOLUTION: The insulative particle-adhered conductive particle according to the present invention includes an insulative particle-adhered conductive particle body, and a coat coating the surface of the insulative particle-adhered conductive particle body, and in which: the insulative particle-adhered conductive particle body has a conductive particle having, at least on a surface thereof, a conductive portion, and a plurality of insulative particles disposed over the surface of the conductive particle; the conductive particle has a plurality of protrusions on the outer surface of the conductive portion; the average height of the protrusion is 0.05 μm or more and 0.5 μm or less; the coat has a first coat portion covering the conductive particle, and a second coat portion covering the surface of the insulative particle; and the ratio of the thickness at the first coat portion to the average particle size of the insulative particle is 2/3 or more and 3 or less.SELECTED DRAWING: Figure 1

Description

  The present invention relates to conductive particles with insulating particles in which insulating particles are arranged on the surface of conductive particles, and a method for producing conductive particles with insulating particles. Moreover, this invention relates to the electrically-conductive material and connection structure using the said electroconductive particle with an insulating particle.

  Anisotropic conductive materials such as anisotropic conductive pastes and anisotropic conductive films are widely known. In these anisotropic conductive materials, conductive particles are dispersed in a binder resin.

  The anisotropic conductive material is used for connection between an IC chip and a flexible printed circuit board, connection between an IC chip and a circuit board having an ITO electrode, and the like. For example, after disposing an anisotropic conductive material between the electrode of the IC chip and the electrode of the circuit board, these electrodes can be electrically connected by heating and pressing.

  As an example of the conductive particles, Patent Document 1 below discloses a conductive particle body having a conductive layer on its surface, an insulating resin layer covering the surface of the conductive particle body, and the conductive material. Conductive particles comprising a plurality of insulating particles disposed on the surface of the particle body are disclosed. The average thickness of the resin layer is 1/6 or less of the average particle diameter of the conductive particle body. The average particle diameter of the insulating particles is 1.5 to 3.5 times the average thickness of the resin layer.

Patent Document 2 below discloses conductive particles in which an insulating layer is formed on the surface of a conductive core having a conductive surface, and insulating fine particles are embedded in the insulating layer. In the example of Patent Document 2, SiO ₂ particles having a particle diameter of 0.5 μm are embedded in an insulating layer having a thickness of 1 μm.

  Further, in Patent Document 2, it is described in claim 5 that “insulating fine particles are embedded in the insulating layer of the conductive core having an insulating layer formed on the surface of the core by hybridization treatment”, paragraph [ [0033] describes that “the embedding of the insulating fine particles 32 can be performed by a known hybridization process”.

  Patent Document 3 below discloses a conductive particle including a conductive particle body with insulating particles and a coating covering the surface of the conductive particle body with insulating particles. The conductive particle body with insulating particles includes conductive particles having a conductive portion on at least a surface, and a plurality of insulating particles arranged on the surface of the conductive particles. The coating has a first coating portion covering the conductive particles and a second coating portion covering the surfaces of the insulating particles. In patent document 3, in Claim 1, it is prescribed | regulated that the thickness in the said 1st film part is 1/2 or less of the average particle diameter of the said insulating particle. Patent Document 3 describes, as Comparative Example 3, conductive particles in which the thickness of the first coating portion is 2/3 of the average particle diameter of the insulating particles.

JP 2011-187332 A JP 2005-209491 A JP 2013-175453 A

  In the conductive particles with insulating particles obtained by the methods described in Patent Documents 1 and 2, the insulating particles are easily detached from the surface of the conductive particles unintentionally before the conductive connection. In Patent Documents 1 and 2, the connection resistance may be relatively high after the conductive connection.

  The present inventor has found that the conductive particles described in Patent Document 3 have a problem that the conduction reliability and the insulation reliability are not sufficiently improved, for example, when the particles are pressed with a low load.

  The objective of this invention is providing the manufacturing method of the electroconductive particle with an insulating particle which can improve conduction | electrical_connection reliability and insulation reliability after electroconductive connection, and the electroconductive particle with an insulating particle. Another object of the present invention is to provide a conductive material and a connection structure using the conductive particles with insulating particles.

  According to a wide aspect of the present invention, a conductive particle body with insulating particles, and a coating covering a surface of the conductive particle body with insulating particles, the conductive particle body with insulating particles, A conductive particle having at least a conductive portion on the surface, and a plurality of insulating particles disposed on the surface of the conductive particle, wherein the conductive particle has a plurality of protrusions on the outer surface of the conductive portion. An average height of the protrusions is 0.05 μm or more and 0.5 μm or less, and the coating includes a first coating portion covering the conductive particles, and a surface of the insulating particles. A conductive film with insulating particles, wherein the ratio of the thickness of the first film portion to the average particle diameter of the insulating particles is 2/3 or more and 3 or less. Sex particles are provided.

  In a specific aspect of the conductive particles with insulating particles according to the present invention, the insulating particles include inorganic particles, or the outer surface of the insulating particles is higher than the glass transition temperature of the coating film. Has a transition temperature.

  On the specific situation with the electroconductive particle with an insulating particle which concerns on this invention, the outer surface of the said insulating particle has a glass transition temperature higher than the glass transition temperature of the said film.

  In a specific aspect of the conductive particles with insulating particles according to the present invention, 90% or more of the total number of the plurality of insulating particles is in contact with the conductive particles.

  In a specific aspect of the conductive particles with insulating particles according to the present invention, a plurality of the insulating particles are not exposed by being covered with the coating film.

  On the specific situation with the electroconductive particle with an insulating particle which concerns on this invention, the said insulating particle has adhered to the outer surface of the said electroconductive part through a chemical bond.

  On the specific situation with the electroconductive particle with the insulating particle which concerns on this invention, the material of the said film is a compound and reactive monomer which have a C6-C22 alkyl group.

  According to a wide aspect of the present invention, there is provided a conductive material including the conductive particles with insulating particles described above and a binder resin.

  In a specific aspect of the conductive material according to the present invention, the conductive material is a conductive paste.

  According to a wide aspect of the present invention, a first connection target member, a second connection target member, and a connection portion connecting the first connection target member and the second connection target member. A connection structure is provided in which the material of the connection portion is the above-described conductive particles with insulating particles or a conductive material including the conductive particles with insulating particles and a binder resin.

  According to a wide aspect of the present invention, there is provided a method for producing the above-described conductive particles with insulating particles, the conductive particles having at least a conductive part on the surface, and a plurality of conductive particles arranged on the surface of the conductive particles. Covering the surface of the conductive particle body with insulating particles having insulating particles to form a film, wherein the conductive particles have a plurality of protrusions on the outer surface of the conductive portion; The first coating portion covering the conductive particles and the second coating portion covering the surface of the insulating particles are an average height of 0.05 μm or more and 0.5 μm or less. And having a conductive film with insulating particles that forms the coating such that the ratio of the thickness of the first coating portion to the average particle diameter of the insulating particles is 2/3 or more and 3 or less. A method for producing particles is provided.

  In a specific aspect of the method for producing conductive particles with insulating particles according to the present invention, a plurality of methods for producing the conductive particles with insulating particles are provided on the surface of the conductive particles having at least a conductive portion on the surface. A step of arranging the insulating particles to obtain the conductive particle body with insulating particles.

  In a specific aspect of the method for producing conductive particles with insulating particles according to the present invention, in the step of obtaining the conductive particle body with insulating particles, the insulating particles are placed on the surface of the conductive particles. Do not attach by hybridization method.

  The conductive particle with insulating particles according to the present invention includes a conductive particle body with insulating particles and a coating covering the surface of the conductive particle body with insulating particles, and the conductive particle with insulating particles. The conductive particle main body has conductive particles having at least a conductive part on the surface, and a plurality of insulating particles arranged on the surface of the conductive particles, and the conductive particles are the outer surface of the conductive part. A plurality of protrusions, and an average height of the protrusions is 0.05 μm or more and 0.5 μm or less, and the coating film includes a first coating portion covering the conductive particles, and the insulating property. And the ratio of the thickness of the first coating portion to the average particle diameter of the insulating particles is 2/3 or more and 3 or less, Improve conduction reliability and insulation reliability when conducting conductive connection be able to.

  In the method for producing conductive particles with insulating particles according to the present invention, conductive particles with insulating particles having the above-described configuration are obtained, and thus conductive connection is performed using the obtained conductive particles with insulating particles. Furthermore, conduction reliability and insulation reliability can be improved.

FIG. 1 is a cross-sectional view showing conductive particles with insulating particles according to the first embodiment of the present invention. FIG. 2 is a cross-sectional view showing conductive particles with insulating particles according to the second embodiment of the present invention. FIG. 3 is a cross-sectional view showing conductive particles with insulating particles according to the third embodiment of the present invention. FIG. 4 is a front cross-sectional view schematically showing a connection structure using the conductive particles with insulating particles shown in FIG. FIG. 5 is a cross-sectional view showing a conventional conductive particle with insulating particles using a hybridization method.

  Details of the present invention will be described below.

(Conductive particles with insulating particles)
Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a cross-sectional view showing conductive particles with insulating particles according to the first embodiment of the present invention. Note that different partial configurations in the respective embodiments can be appropriately replaced and combined.

  A conductive particle 1 with insulating particles shown in FIG. 1 includes a conductive particle body 2 with insulating particles and a coating 3 covering the surface of the conductive particle body 2 with insulating particles. The coating 3 is attached to the surface of the conductive particle body 2 with insulating particles. The coating 3 covers the entire surface of the conductive particle body 2 with insulating particles.

  The conductive particle body 2 with insulating particles includes conductive particles 11 and a plurality of insulating particles 15 arranged on the surface of the conductive particles 11. The plurality of insulating particles 15 are attached to the surface of the conductive particles 11. The insulating particles 15 are formed of an insulating material.

  The coating 3 covers the surface of the conductive particles 11 and the surface of the insulating particles 15. The coating 3 includes a first coating portion 3 a that covers the surface of the conductive particles 11 and a second coating portion 3 b that covers the surface of the insulating particles 15. The first coating portion 3a and the second coating portion 3b are continuous. The first coating portion 3a covers the surface of the conductive particles 11 in the portion of the conductive particles 11 where the insulating particles 15 are not in contact. The second coating portion 3 b covers the surface of the insulating particles 15 in the portion of the insulating particles 15 where the conductive particles 11 are not in contact. The coating 3 has unevenness as a whole on the outer surface.

  The conductive particles 11 have base material particles 12 and a conductive layer 13 provided on the surface of the base material particles 12. The conductive layer 13 is a conductive part. The conductive layer 13 covers the surface of the base particle 12. The conductive layer 13 is in contact with the base particle 12. The conductive particles 11 are coated particles in which the surface of the base particle 12 is coated with the conductive layer 13. The conductive particles 11 have a conductive layer 13 on the surface.

  The conductive particles 11 have a plurality of protrusions 11 a on the outer surface of the conductive layer 13. The conductive layer 13 has a plurality of protrusions 13a on the outer surface. A plurality of core substances 14 are arranged on the surface of the base particle 12. The core substance 14 is in contact with the surface of the base particle 12. A plurality of core materials 14 are embedded in the conductive layer 13. The conductive layer 13 covers the base particles 12 and the core substance 14. The core substance 14 is disposed inside the protrusions 11a and 13a. The conductive layer 13 covers a plurality of core materials 14. The outer surface of the conductive layer 13 is raised by the plurality of core materials 14, and protrusions 11 a and 13 a are formed.

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

  A conductive particle 21 with insulating particles shown in FIG. 2 includes a conductive particle body 22 with insulating particles and a coating 3 covering the surface of the conductive particle body 22 with insulating particles.

  The conductive particle body 22 with insulating particles includes conductive particles 31 and a plurality of insulating particles 35 arranged on the surface of the conductive particles 31. The insulating particles 35 are attached to the surface of the conductive particles 31. Except that the insulating particles are different and the core substance is not used, the conductive particles 21 with insulating particles are configured in the same manner as the conductive particles 1 with insulating particles, and with insulating particles. The conductive particle body 22 is configured in the same manner as the conductive particle body 2 with insulating particles.

  The conductive particle 31 includes the base particle 12 and a conductive portion 32 disposed on the surface of the base particle 12. The conductive particles 31 do not have a core substance. The conductive portion 32 has a first portion and a second portion that is thicker than the first portion. The conductive particles 31 have a plurality of protrusions 31 a on the outer surface of the conductive portion 32. A portion excluding the plurality of protrusions 31 a is the first portion of the conductive portion 32. The plurality of protrusions 31a are located in the second portion where the conductive portion 32 is thick. The conductive portion 32 has a plurality of protrusions 32a on the outer surface. In order to form protrusions on the outer surface of the conductive portion, a core material may be used or a core material may not be used.

  The insulating particles 35 include an insulating particle body 35a and a layer 35b that covers the surface of the insulating particle body 35a and is formed of a polymer compound. The material of the layer 35b is a polymer compound, and the layer 35b is a polymer compound layer. Due to the presence of the layer 35b, the adhesion of the insulating particles 35 to the conductive particles 31 can be appropriately increased.

  The layer 35b covers the entire surface of the insulating particle main body 35a. Accordingly, the layer 35b is disposed between the conductive particles 31 and the insulating particle main body 35a. The layer 35b may be present so as to cover at least a part of the surface of the insulating particle main body 35a, and may not cover the entire surface of the insulating particle main body 35a. The layer 35b is preferably disposed between the conductive particles 31 and the insulating particle main body 35a.

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

  A conductive particle 41 with insulating particles shown in FIG. 3 includes a conductive particle body 42 with insulating particles and a coating 43 covering the surface of the conductive particle body 42 with insulating particles. The coating 43 is attached to the surface of the conductive particle body 42 with insulating particles.

  The conductive particle body 42 with insulating particles includes conductive particles 51 and a plurality of insulating particles 15 attached to the surface of the conductive particles 51.

  The coating 43 covers the surface of the conductive particles 51 and the surface of the insulating particles 15. The coating 43 has a first coating portion 43 a covering the surface of the conductive particles 51 and a second coating portion 43 b covering the surface of the insulating particles 15. The first coating portion 43a and the second coating portion 43b are continuous. The first coating portion 43 a covers the surface of the conductive particles 51 in the portion of the conductive particles 51 where the insulating particles 15 are not in contact. The second coating portion 43b covers the surface of the insulating particles 15 in the portion of the insulating particles 15 where the conductive particles 51 are not in contact. When a line (broken line shown in FIG. 3) is drawn from the center of the conductive particles 41 with insulating particles toward the outside, the second coating portion 43 b is on the line passing through the insulating particles 15. It is located outside. The coating 43 has no irregularities on the outer surface as a whole and has a spherical outer diameter.

  The conductive particles 51 include base material particles 12 and a conductive layer 52 provided on the surface of the base material particles 12. The conductive layer 52 is a conductive part. The conductive layer 52 has a first conductive layer 52A provided on the surface of the base particle 12 and a second conductive layer 52B provided on the outer surface of the first conductive layer 52A. The conductive particles 51 have a plurality of core materials 14 on the outer surface of the first conductive layer 52A. The second conductive layer 52B covers the first conductive layer 52A and the core substance 14. The base particles 12 and the core substance 14 are arranged with a space therebetween. A first conductive layer 52A exists between the base particle 12 and the core substance 14. By covering the core substance 14 with the second conductive layer 52 </ b> B, the conductive particles 51 have a plurality of protrusions 51 a on the outer surface of the conductive layer 52. The conductive layer 52 and the second conductive layer 52B have a plurality of protrusions 52a on the outer surface. The core substance 14 is disposed inside the protrusions 51a and 52a. The outer surfaces of the conductive layer 52 and the second conductive layer 52B are raised by the core substance 14, and a plurality of protrusions 51a and 52a are formed.

  In each of the conductive particles with insulating particles 1, 21, 41, the ratio of the thickness of the first coating portions 3a, 43a to the average particle diameter of the insulating particles 15, 35 is 2/3 or more and 3 or less. is there.

  The distinction between the first coating portion and the second coating portion, and the thicknesses of the first coating portion and the second coating portion will be specifically described with reference to FIG.

  Two tangent lines are drawn for one insulating particle 15 from the center of the conductive particle 1 with insulating particles. A region between one tangent line in one insulating particle and one tangent line in the adjacent insulating particle is the first coating portion 3a. The first coating portion 3a is a region R1 in FIG. In FIG. 1, only one region R1 is shown, but there are a plurality of regions R1. Insulating particles 15 do not exist in region R1. In the region R1 of the first coating portion 3a, the distance of the first coating portion 3a in the direction connecting the center of the conductive particles 1 with insulating particles and the surface of the conductive particles 1 with insulating particles is defined as a first distance. The thickness of the coating portion 3a. The thickness of the 1st film part 3a is the average of the thickness in whole area | region R1. A region between two tangents in one insulating particle is the second coating portion 3b. The second coating portion 3b is a region R2 in FIG. In FIG. 1, only one region R2 is shown, but there are a plurality of regions R2. In the region R2 of the second coating portion 3b, the distance between the second coating portion 3b in the direction connecting the center of the conductive particles 1 with insulating particles and the surface of the conductive particles 1 with insulating particles is set to a second value. The thickness of the coating portion 3b. The thickness of the second coating portion 3b is an average of the thickness in the entire region R2.

  The coating has a first coating portion covering the conductive particles and a second coating portion covering the surface of the insulating particles, and the thickness of the first coating portion is an average of the insulating particles. When the particle diameter is 2/3 or more and 3 or less, the conduction reliability and the insulation reliability can be improved after the conductive connection. Specifically, when the upper and lower electrodes are connected using conductive particles with insulating particles, the upper and lower electrodes to be connected are electrically connected by the conductive particles in the conductive particles with insulating particles. Thus, the conduction reliability between the upper and lower electrodes can be improved. Furthermore, when the upper and lower electrodes are connected using conductive particles with insulating particles, the electrodes adjacent to each other in the horizontal direction that should not be connected are difficult to be connected via the plurality of conductive particles. The insulation reliability between the electrodes adjacent to each other can be improved. Further, it is possible to make it difficult to unintentionally detach the insulating particles from the surface of the conductive particles before the conductive connection, and to easily detach the insulating particles from the surface of the conductive particles during the conductive connection.

  Furthermore, even when the conductive particles have a plurality of protrusions on the outer surface of the conductive portion, the protrusion portions are likely to come into contact with the upper and lower electrodes, and indentations are also easily formed on the electrodes, thereby improving conduction reliability. it can. In addition, since the conductive particles have a plurality of protrusions on the outer surface of the conductive part, the coating on the protrusions is effectively eliminated even though the coating on the protrusions is somewhat thick, thereby improving conduction reliability. Can be increased.

  When the coating has only the first coating portion covering the conductive particles, or only the second coating portion covering the surface of the insulating particles, the conductive coating is not yet connected. In addition, the insulating particles are easily detached from the surface of the conductive particles unintentionally. For example, when the conductive particles with insulating particles are dispersed in the binder resin, the insulating particles may be easily detached from the surface of the conductive particles. Furthermore, when a plurality of conductive particles with insulating particles are in contact with each other, the insulating particles are easily detached from the surface of the conductive particles due to an impact at the time of contact. Therefore, when conductive particles with insulating particles are used for connection between electrodes, there are no insulating particles between adjacent conductive particles, and the adjacent electrodes that should not be connected are electrically connected. May be connected. Such problems can be solved by the conductive particles with insulating particles according to the present invention.

  When the ratio of the thickness of the first coating portion to the average particle diameter of the insulating particles exceeds 3, the insulating particles are less likely to be detached from the surface of the conductive particles during conductive connection. As a result, when the connection structure is obtained using the conductive particles with insulating particles, the possibility that the connection resistance between the electrodes is increased or a connection failure is likely to occur is increased.

  Furthermore, in the conductive particles with insulating particles according to the present invention, the ratio of the average height of the protrusions to the average particle diameter of the insulating particles (average height) from the viewpoint of effectively increasing the conduction reliability and the insulation reliability. (Sa / average particle diameter) is 0.1 or more and 5 or less. From the viewpoint of more effectively increasing the conduction reliability and the insulation reliability, the ratio (average height / average particle diameter) is preferably 0.5 or more, and preferably 3 or less. Further, when the ratio (average height / average particle diameter) is not more than the above upper limit, the protrusions are not easily broken, and the conduction reliability is increased.

  The height of the projection is a virtual line of the conductive portion (dashed line shown in FIG. 1) on the assumption that there is no projection on the line (dashed line L1 shown in FIG. 1) connecting the center of the conductive particles and the tip of the projection. L2) Indicates the distance from the top (on the outer surface of the spherical conductive particles assuming no projection) to the tip of the projection. That is, in FIG. 1, the distance from the intersection of the broken line L1 and the broken line L2 to the tip of the protrusion is shown.

  From the viewpoint of further increasing the electrical conductivity, and from the viewpoint of effectively suppressing the unintentional detachment of the insulating particles from the surface of the conductive particles, the thinner the first coating portion, the better. The ratio (thickness / average particle diameter) of the thickness of the first coating portion to the average particle diameter of the insulating particles is preferably 2.5 or less, more preferably 2 or less. In order to effectively perform the function of preventing the detachment of the insulating particles before the conductive connection, the ratio of the thickness in the first coating portion to the average particle size of the insulating particles (thickness / average particle size) is preferably Is 3/4 or more, more preferably 1 or more.

  The “average particle diameter” of the insulating particles indicates a number average particle diameter. The average particle diameter of the insulating particles is obtained by observing 50 arbitrary insulating particles with an electron microscope or an optical microscope and calculating an average value.

  The thickness of the first coating portion and the thickness of the second coating portion may be the same or different. The thickness of the first coating portion is preferably 10 nm or more, more preferably 20 nm or more, preferably 150 nm or less, more preferably 80 nm or less. The thickness of the second coating portion is preferably 10 nm or more, more preferably 40 nm or more, preferably 300 nm or less, more preferably 150 nm or less.

  From the viewpoint of effectively preventing unintentional detachment of the insulating particles from the surface of the conductive particles before the conductive connection, the total number of the plurality of insulating particles in the conductive particles with insulating particles is It is preferable that 50% or more of them are in contact with the conductive particles. 90% or more of the total number of the plurality of insulating particles in the conductive particles with insulating particles is more preferably in contact with the conductive particles, and 95% or more is in contact with the conductive particles. More preferably.

  From the viewpoint of effectively preventing unintentional detachment of the insulating particles from the surface of the conductive particles before the conductive connection, the first coating portion and the second coating portion are continuous. Is preferred. The coating is preferably a coating in which the first coating portion and the second coating portion are continuous.

  From the viewpoint of effectively preventing unintentional detachment of the insulating particles from the surface of the conductive particles before the conductive connection, a plurality of the insulating particles are exposed by being covered with the coating film. Preferably not. It is preferable that the conductive particles with insulating particles do not have insulating particles that are not covered with a coating film and do not have exposed insulating particles. It is preferable that the conductive particles with insulating particles do not have exposed insulating particle portions.

  From the viewpoint of effectively preventing unintentional detachment of the insulating particles from the surface of the conductive particles before the conductive connection, the insulating particles adhere to the outer surface of the conductive portion through a chemical bond. It is preferable.

  Moreover, it becomes difficult to produce rust in the conductive layer in the electroconductive particle with an insulating particle because the film coat | covers the surface of the electroconductive particle main body with an insulating particle. The coating imparts a rust prevention effect. For this reason, the electroconductivity of the electroconductive particle in the electroconductive particle with an insulating particle becomes high, and can maintain high electroconductivity over a long period of time. Therefore, when the electrodes are connected using conductive particles with insulating particles, the conduction reliability can be improved.

  Moreover, it is preferable that the surface of the electroconductive particle main body with an insulating particle is coat | covered with the film, and the material of this film is a compound and reactive monomer which have a C6-C22 alkyl group. It is preferable that the said film is formed with the compound and reactive monomer which have a C6-C22 alkyl group. The coating is preferably a reaction product of a compound having an alkyl group having 6 to 22 carbon atoms and a reactive monomer. As a result, rust is more unlikely to occur in the conductive layer of the conductive particles with insulating particles.

  The coating is preferably attached to the surface of the conductive particle body with insulating particles. In the conductive particles with insulating particles, the coating preferably covers the entire surface of the conductive particle body with insulating particles.

  The coating does not necessarily have to cover the entire surface of the conductive particle body with insulating particles. If the coating has a first coating portion covering the conductive particles and a second coating portion covering the surface of the insulating particles, it has only the first coating portion or the second coating portion. Compared with the case of having only the coating portion, the prevention of detachment before conductive connection and the detachability at the time of conductive connection can be improved in a balanced manner. Further, at least a part of the surface of the conductive layer is covered with a coating, and particularly, a coating formed of a compound having an alkyl group having 6 to 22 carbon atoms is coated. In the portion where is formed, rust of the conductive layer can be suppressed.

  Hereinafter, details of the coating and details of the conductive particle body with insulating particles will be described. In the following description, “(meth) acryl” means one or both of “acryl” and “methacryl”, and “(meth) acrylate” means one or both of “acrylate” and “methacrylate”. means.

[Coating]
In order to make it difficult for rust to occur in the conductive part, the coating is preferably formed by polymerizing a compound having an alkyl group having 6 to 22 carbon atoms (hereinafter also referred to as compound A) and a reactive monomer. . Moreover, it is preferable that the compound A has a reactive functional group. When the carbon number of the alkyl group is less than 6, rust is likely to occur on the outer surface of the conductive portion. When carbon number of the said alkyl group exceeds 22, the electroconductivity of the electroconductive particle with an insulating particle will become low. From the viewpoint of further increasing the conductivity of the conductive particles with insulating particles, the alkyl group in the compound A preferably has 16 or less carbon atoms. The alkyl group may have a linear structure or a branched structure. The alkyl group preferably has a linear structure.

  The compound A is not particularly limited as long as it has an alkyl group having 6 to 22 carbon atoms. The compound A has a phosphate ester having an alkyl group having 6 to 22 carbon atoms or a salt thereof, a phosphite ester having an alkyl group having 6 to 22 carbon atoms or a salt thereof, and an alkyl group having 6 to 22 carbon atoms. It is preferably at least one selected from the group consisting of alkoxysilanes, alkylthiols having an alkyl group having 6 to 22 carbon atoms, and dialkyl disulfides having an alkyl group having 6 to 22 carbon atoms. That is, the compound A having an alkyl group having 6 to 22 carbon atoms is at least one selected from the group consisting of phosphate esters or salts thereof, phosphite esters or salts thereof, alkoxysilanes, alkylthiols, and dialkyl disulfides. It is preferable that By using these preferable compounds A, it is possible to further prevent rust from being generated in the conductive portion. From the viewpoint of making rust more difficult to occur, the compound A is preferably at least one selected from the group consisting of the phosphate ester or a salt thereof, a phosphite ester or a salt thereof and an alkoxysilane, More preferably, the phosphoric acid ester or a salt thereof and a phosphorous acid ester or a salt thereof are at least one of them. As for the said compound A, only 1 type may be used and 2 or more types may be used together.

  The compound A preferably has a reactive functional group capable of reacting with the conductive particles. The compound A preferably has a reactive functional group capable of reacting with the insulating particles and the reactive monomer. The coating is preferably chemically bonded to the conductive particle body with insulating particles. The coating is preferably chemically bonded to the conductive particles. The coating is preferably chemically bonded to the insulating particles. More preferably, the coating is chemically bonded to the conductive particles and the insulating particles. The presence of the reactive functional group and the chemical bond make it difficult for the coating to peel off. As a result, rust is less likely to occur in the conductive layer, and the insulating particles are more difficult to be detached from the surface of the conductive particles unintentionally.

  Examples of the phosphoric acid ester having an alkyl group having 6 to 22 carbon atoms or a salt thereof include, for example, phosphoric acid hexyl ester, phosphoric acid heptyl ester, phosphoric acid monooctyl ester, phosphoric acid monononyl ester, phosphoric acid monodecyl ester, Monoundecyl phosphate, monododecyl phosphate, monotridecyl phosphate, monotetradecyl phosphate, monopentadecyl phosphate, monohexyl phosphate monosodium salt, monoheptyl phosphate monosodium Salts, monooctyl phosphate monosodium salt, monononyl phosphate monosodium salt, monodecyl phosphate monosodium salt, monoundecyl phosphate monosodium salt, monododecyl phosphate monosodium salt, Phosphate mono tridecyl ester monosodium salt, phosphate acid mono tetradecyl ester monosodium salt and phosphoric acid mono pentadecyl ester monosodium salt. You may use the potassium salt of the said phosphate ester.

  Examples of the phosphite ester having an alkyl group having 6 to 22 carbon atoms or a salt thereof include, for example, hexyl phosphite ester, heptyl phosphite ester, monooctyl phosphite ester, monononyl phosphite ester, Phosphoric acid monodecyl ester, phosphorous acid monoundecyl ester, phosphorous acid monododecyl ester, phosphorous acid monotridecyl ester, phosphorous acid monotetradecyl ester, phosphorous acid monopentadecyl ester, phosphorous acid monohexyl Ester monosodium salt, phosphorous acid monoheptyl ester monosodium salt, phosphorous acid monooctyl ester monosodium salt, phosphorous acid monononyl ester monosodium salt, phosphorous acid monodecyl ester monosodium salt, phosphorous acid monoun Decyl ester monosodium salt, phosphorous acid Dodecyl ester monosodium salt, phosphorous acid mono-tridecyl ester monosodium salt, phosphorous acid mono-tetradecyl ester monosodium salt and phosphorous acid mono-pentadecyl ester monosodium salt. You may use the potassium salt of the said phosphite.

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

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

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

  The reactive monomer is not particularly limited as long as it has a reactive functional group. Examples of the reactive functional group include a vinyl group, a (meth) acryloyl group, a carboxyl group, and a glycidyl group. As the reactive monomer, specifically, a compound for forming resin particles to be described later can be similarly used.

[Conductive particle body with insulating particles]
The conductive particles may have at least a conductive part on the surface and a plurality of protrusions on the outer surface of the conductive part. The conductive part is, for example, a conductive layer. The conductive particles may be base particles and conductive particles having a conductive layer disposed on the surface of the base particles, or may be metal particles whose entirety is a conductive layer. Among these, from the viewpoint of reducing the cost and increasing the flexibility of the conductive particles to increase the conduction reliability between the electrodes, the base particles and the conductive material disposed on the surface of the base particles are used. The electroconductive particle which has a part is preferable.

  Examples of the substrate particles include resin particles, inorganic particles excluding metal particles, organic-inorganic hybrid particles, and metal particles. The substrate particles are preferably substrate particles excluding metal particles, and are preferably resin particles or organic-inorganic hybrid particles. The base particles may be core-shell particles. The core may be an organic core, and the shell may be an inorganic shell.

  The substrate particles are preferably resin particles formed of a resin. When connecting the electrodes using the conductive particles with insulating particles, the conductive particles with insulating particles are compressed by placing the conductive particles with insulating particles between the electrodes and then pressing them. When the substrate particles are resin particles, the conductive particles are likely to be deformed during the pressure bonding, and the contact area between the conductive particles and the electrode is increased. For this reason, the conduction | electrical_connection reliability between electrodes becomes high.

  Various organic materials are suitably used as the resin for forming the resin particles. Examples of the resin for forming the resin particles include polyolefin resins such as polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyvinylidene chloride, polyisobutylene, and polybutadiene; acrylic resins such as polymethyl methacrylate and polymethyl acrylate; Alkylene terephthalate, polycarbonate, polyamide, phenol formaldehyde resin, melamine formaldehyde resin, benzoguanamine formaldehyde resin, urea formaldehyde resin, phenol resin, melamine resin, benzoguanamine resin, urea resin, epoxy resin, unsaturated polyester resin, saturated polyester resin, polysulfone, polyphenylene Oxide, polyacetal, polyimide, polyamideimide, polyether ether Ketones, polyether sulfones, and polymers such as obtained by a variety of polymerizable monomer having an ethylenically unsaturated group is polymerized with one or more thereof. Resin for forming the resin particles can be designed and synthesized, and the hardness of the base particles can be easily controlled within a suitable range, which is suitable for conductive materials and having physical properties at the time of compression. Is preferably a polymer obtained by polymerizing one or more polymerizable monomers having a plurality of ethylenically unsaturated groups.

  When the resin particles are obtained by polymerizing a monomer having an ethylenically unsaturated group, the monomer having the ethylenically unsaturated group may be a non-crosslinkable monomer or a crosslinkable monomer. And a polymer.

  Examples of the non-crosslinkable monomer include styrene monomers such as styrene and α-methylstyrene; carboxyl group-containing monomers such as (meth) acrylic acid, maleic acid, and maleic anhydride; (Meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, cetyl (meth) acrylate, stearyl (meth) acrylate, cyclohexyl ( Alkyl (meth) acrylates such as meth) acrylate and isobornyl (meth) acrylate; oxygen such as 2-hydroxyethyl (meth) acrylate, glycerol (meth) acrylate, polyoxyethylene (meth) acrylate and glycidyl (meth) acrylate (Meth) acrylates; nitrile-containing monomers such as (meth) acrylonitrile; vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether; vinyl acids such as vinyl acetate, vinyl butyrate, vinyl laurate, vinyl stearate Esters; Unsaturated hydrocarbons such as ethylene, propylene, isoprene and butadiene; Halogen-containing monomers such as trifluoromethyl (meth) acrylate, pentafluoroethyl (meth) acrylate, vinyl chloride, vinyl fluoride and chlorostyrene Is mentioned.

  Examples of the crosslinkable monomer include tetramethylolmethane tetra (meth) acrylate, tetramethylolmethane tri (meth) acrylate, tetramethylolmethane di (meth) acrylate, trimethylolpropane tri (meth) acrylate, and dipenta 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) Polyfunctional (meth) acrylates such as acrylate, (poly) tetramethylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate; triallyl (iso) cyanure And silane-containing monomers such as triallyl trimellitate, divinylbenzene, diallyl phthalate, diallylacrylamide, diallyl ether, γ- (meth) acryloxypropyltrimethoxysilane, trimethoxysilylstyrene, vinyltrimethoxysilane It is done.

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

  When the substrate particles are inorganic particles or organic-inorganic hybrid particles excluding metal particles, examples of the inorganic material that is a material of the substrate particles include silica and carbon black. The inorganic substance is preferably not a metal. The particles formed from the silica are not particularly limited. For example, after forming a crosslinked polymer particle by hydrolyzing a silicon compound having two or more hydrolyzable alkoxysilyl groups, firing may be performed as necessary. The particle | grains obtained by performing are mentioned. Examples of the organic / inorganic hybrid particles include organic / inorganic hybrid particles formed of a crosslinked alkoxysilyl polymer and an acrylic resin.

  When the substrate particles are metal particles, examples of the metal for forming the metal particles include silver, copper, nickel, silicon, gold, and titanium. However, the substrate particles are preferably not metal particles.

  The metal for forming the conductive part is not particularly limited. Furthermore, in the case where the conductive particles are metal particles that are conductive parts as a whole, the metal for forming the metal particles is not particularly 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, tungsten, and molybdenum. , Silicon and alloys thereof. Examples of the metal include tin-doped indium oxide (ITO) and solder. Especially, since the connection resistance between electrodes can be made still lower, an alloy containing tin, nickel, palladium, copper or gold is preferable, and nickel or palladium is preferable.

  As the metal constituting the conductive part is more likely to be rusted, the coating effect by the coating is more remarkable. In the conductive part formed of nickel, copper or tin, rust is relatively likely to occur on the outer surface of the conductive part. By covering the outer surface of such a conductive part with a film, it is possible to effectively suppress rust from being generated on the outer surface of the conductive part. Since the covering effect by the said film is acquired effectively, the said electroconductive part may contain nickel, copper, or tin.

  In many cases, hydroxyl groups are present on the outer surface of the conductive portion by oxidation. Generally, a hydroxyl group exists on the outer surface of a conductive portion formed of nickel by oxidation. The conductive part having such a hydroxyl group is chemically bonded to the film.

  The conductive layer may be formed of a single layer. The conductive layer may be formed of a plurality of layers. That is, the conductive layer may have a stacked structure of two or more layers. When the conductive layer is formed of a plurality of layers, the outermost layer is preferably a gold layer, a nickel layer, a palladium layer, a copper layer, or an alloy layer containing tin and silver, and is a gold layer. Is more preferable. When the outermost layer is these preferred conductive layers, the connection resistance between the electrodes is further reduced. Moreover, when the outermost layer is a gold layer, the corrosion resistance is further enhanced.

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

  The average particle diameter of the conductive particles is preferably 0.5 μm or more, more preferably 1 μm or more, preferably 100 μm or less, more preferably 20 μm or less, and even more preferably 5 μm or less. When the average particle diameter of the conductive particles is not less than the above lower limit and not more than the above upper limit, the contact area between the conductive particles and the electrodes is sufficiently large when the electrodes are connected using the conductive particles with insulating particles. And it becomes difficult to form aggregated conductive particles when the conductive layer is formed. Further, the distance between the electrodes connected via the conductive particles does not become too large, and the conductive layer is difficult to peel from the surface of the base material particles.

  The “average particle size” of the conductive particles indicates a number average particle size. The average particle diameter of the conductive particles can be obtained by observing 50 arbitrary conductive particles with an electron microscope or an optical microscope and calculating an average value.

  The thickness of the conductive part is preferably 5 nm or more, more preferably 10 nm or more, further preferably 20 nm or more, particularly preferably 50 nm or more, preferably 1000 nm or less, more preferably 800 nm or less, still more preferably 500 nm or less, particularly preferably. Is 400 nm or less, most preferably 300 nm or less. The thickness of the conductive portion is the total thickness of the multilayer conductive portions (first and second conductive portions) when the conductive portion is a multilayer (such as the first and second conductive portions). When the thickness of the entire conductive portion is not less than the above lower limit, the conductivity of the conductive particles is further improved. When the thickness of the entire conductive part is less than or equal to the above upper limit, the difference in thermal expansion coefficient between the base particle and the conductive part is small, and the metal layer is difficult to peel from the base particle.

  When the conductive part is a multilayer, the thickness of the conductive part of the outermost layer is preferably 1 nm or more, more preferably 10 nm or more, preferably 500 nm or less, more preferably 100 nm or less. When the thickness of the conductive portion of the outermost layer is not less than the above lower limit and not more than the above upper limit, the coating with the conductive portion of the outermost layer can be made uniform, the corrosion resistance is sufficiently high, and the connection resistance between the electrodes is sufficiently high Lower. In addition, when the outermost layer is more expensive than the inner-layer conductive portion, the thinner the outermost layer, the lower the cost.

  The thickness of the said electroconductive part can be measured by observing the cross section of electroconductive particle or electroconductive particle with an insulating particle using a transmission electron microscope (TEM), for example.

  The conductive particles have a plurality of protrusions on the outer surface of the conductive part. There are a plurality of protrusions. An oxide film is often formed on the surface of the electrode connected by the conductive particles with insulating particles. When the conductive particles with insulating particles having protrusions on the outer surface of the conductive part are used, the oxide film can be effectively eliminated by the protrusions by placing the conductive particles between the electrodes and pressing them. For this reason, an electrode and an electroconductive part contact more reliably and the connection resistance between electrodes becomes low. Furthermore, when the electrodes are connected, the insulating particles between the conductive particles and the electrodes can be effectively eliminated by the protrusions of the conductive particles. For this reason, the conduction | electrical_connection reliability between electrodes becomes high.

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

  As a method for forming the protrusions, after a core substance is attached to the surface of the base particle, a conductive part is formed by electroless plating, and a conductive part is formed by electroless plating on the surface of the base particle. Thereafter, a method of attaching a core substance and further forming a conductive portion by electroless plating can be used. As another method for forming the protrusion, a first conductive part is formed on the surface of the base particle, and then a core substance is disposed on the first conductive part, and then the second conductive part. And a method of adding a core substance in the middle of forming a conductive part on the surface of the base particle.

  As a method of arranging the core substance on the surface of the base particle, for example, the core substance is added to the dispersion of the base particle, and the core substance is applied to the surface of the base particle, for example, van der Waals force. And a method for adding a core substance to a container containing base particles and attaching the core substance to the surface of the base particles by a mechanical action such as rotation of the container, and a core substance. Examples thereof include a method in which nickel powder is generated in a plating bath without being added, and the nickel powder is accumulated and adhered to the surface of the substrate particles by van der Waals force. Especially, since the quantity of the core substance to adhere is easy to control, the method of making a core substance accumulate and adhere on the surface of the base particle in a dispersion liquid is preferable.

  The conductive particles may have a first conductive portion on the surface of the base particle, and may have a second conductive portion on the first conductive portion. In this case, a core substance may be attached to the outer surface of the first conductive part. The core substance is preferably covered with the second conductive portion. The thickness of the first conductive part is preferably 0.05 μm or more, and preferably 0.5 μm or less. The conductive particles form a first conductive part on the surface of the base particle, and then attach a core substance on the outer surface of the first conductive part, and then the first conductive part and the core substance It is preferable to be obtained by forming the second conductive portion on the surface of the substrate.

  Examples of the material of the core substance include a conductive substance and a non-conductive substance. Examples of the conductive material include conductive non-metals such as metals, metal oxides, and graphite, and conductive polymers. Examples of the conductive polymer include polyacetylene. Examples of the nonconductive material include silica, alumina, and zirconia. Among them, metal is preferable because conductivity can be increased. The core substance is preferably metal particles.

  Examples of the metal include gold, silver, copper, platinum, zinc, iron, lead, tin, aluminum, cobalt, indium, nickel, chromium, titanium, antimony, bismuth, germanium and cadmium, and tin-lead. Examples include alloys composed of two or more metals such as alloys, tin-copper alloys, tin-silver alloys, tin-lead-silver alloys, and tungsten carbide. Of these, nickel, copper, silver or gold is preferable. The metal constituting the core substance may be the same as or different from the metal constituting the conductive part (conductive layer).

  The shape of the core material is not particularly limited. The shape of the core substance is preferably a lump. Examples of the core substance include a particulate lump, an agglomerate in which a plurality of fine particles are aggregated, and an irregular lump.

  The average height of the plurality of protrusions is preferably 0.05 μm or more, more preferably 0.10 μm or more, preferably 0.5 μm or less, more preferably 0.3 μm or less. When the average height of the protrusions is not less than the above lower limit and not more than the above upper limit, the connection resistance between the electrodes is effectively reduced.

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

  The “average diameter (average particle diameter)” of the core substance indicates a number average diameter (number average particle diameter). The average diameter of the core substance is determined by measuring the number average particle diameter by measuring with a pore electrical resistance method Coulter counter Multisizer 4 (manufactured by Beckman Coulter).

  The insulating particles are particles having insulating properties. Insulating particles are smaller than conductive particles. When the electrodes are connected using conductive particles with insulating particles, the insulating particles can prevent a short circuit between adjacent electrodes. Specifically, when the conductive particles with a plurality of insulating particles are in contact with each other, there are insulating particles between the conductive particles in the conductive particles with a plurality of insulating particles. Short circuit between the electrodes adjacent in the lateral direction can be prevented. In addition, the insulating particle between an electroconductive part and an electrode can be easily excluded by pressurizing the electroconductive particle with an insulating particle with two electrodes in the case of the connection between electrodes. Since the protrusion is provided on the surface of the conductive particle, the insulating particle between the conductive portion and the electrode can be more easily eliminated.

  Examples of the material constituting the insulating particles include an insulating resin and an insulating inorganic substance. As said insulating resin, the said resin quoted as resin for forming the resin particle which can be used as a base particle is mentioned. As said insulating inorganic substance, the said inorganic substance quoted as an inorganic substance for forming the inorganic particle which can be used as a base particle is mentioned.

  Specific examples of the insulating resin that is the material of the insulating particles include polyolefins, (meth) acrylate polymers, (meth) acrylate copolymers, block polymers, thermoplastic resins, crosslinked thermoplastic resins, heat Examples thereof include curable resins and water-soluble resins.

  Examples of the polyolefins include polyethylene, ethylene-vinyl acetate copolymer, and ethylene-acrylic acid ester copolymer. Examples of the (meth) acrylate polymer include polymethyl (meth) acrylate, polyethyl (meth) acrylate, and polybutyl (meth) acrylate. Examples of the block polymer include polystyrene, styrene-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. As said thermosetting resin, an epoxy resin, a phenol resin, a melamine resin, etc. are mentioned. Examples of the water-soluble resin include polyvinyl alcohol, polyacrylic acid, polyacrylamide, polyvinyl pyrrolidone, polyethylene oxide, and methyl cellulose. Of these, water-soluble resins are preferable, and polyvinyl alcohol is more preferable.

  From the viewpoint of further increasing the detachability of the insulating particles during thermocompression bonding, the insulating particles include inorganic particles, or the outer surface of the insulating particles is higher than the glass transition temperature of the coating film. It preferably has a glass transition temperature, and the inorganic particles are preferably silica particles. The insulating particles preferably include inorganic particles. The outer surface of the insulating particles preferably has a glass transition temperature higher than the glass transition temperature of the coating film. When the insulating particles do not have a layer formed of the polymer compound on the surface, the insulating particles are inorganic particles, or the insulating particles are from the glass transition temperature of the coating film. Preferably have a high glass transition temperature. When insulating particles whose surface is covered with a layer formed of the above polymer compound are used, the insulating particle body is preferably inorganic particles.

  From the viewpoint of further improving the conduction reliability and the insulation reliability, the absolute value of the difference between the glass transition temperature of the outer surface of the insulating particles and the glass transition temperature of the insulating layer is preferably more than 0 ° C., more preferably Is 10 ° C. or higher, more preferably 30 ° C. or higher, preferably 100 ° C. or lower, more preferably 50 ° C. or lower.

  Examples of the inorganic particles include shirasu particles, hydroxyapatite particles, magnesia particles, zirconium oxide particles, and silica particles. Examples of the silica particles include pulverized silica and spherical silica, and spherical silica is preferably used. The silica particles preferably have a functional group capable of chemical bonding such as a carboxyl group and a hydroxyl group on the surface, and more preferably have a hydroxyl group. Inorganic particles are relatively hard, especially silica particles are relatively hard. When the conductive particle body with insulating particles having such hard insulating particles is used, when the conductive particle body with insulating particles and the binder resin are kneaded, the surface of the conductive particles is hard. Insulating particles are easily detached. However, when the conductive particles with insulating particles according to the present invention are used, even when the hard insulating particles are used, the hard insulating particles can be prevented from being detached by the coating during the kneading. . The layer formed of the polymer compound serves as a flexible layer, for example.

  The polymer compound in the layer formed of the polymer compound or the compound that becomes the polymer compound by polymerization or the like is preferably a compound having a polymerizable reactive functional group. The polymerizable reactive functional group is preferably an unsaturated double bond. For example, a compound having an unsaturated double bond (a compound that becomes a polymer compound) may be subjected to a polymerization reaction on the surface of the insulating particle main body, and the reactive functional group on the surface of the polymer compound and the insulating particle main body. And may be reacted. Examples of the polymer compound or the compound to be the polymer compound include a compound having a (meth) acryloyl group, a compound having an epoxy group, and a compound having a vinyl group. From the viewpoint of suppressing detachment of the insulating particles from the surface of the conductive particles when dispersing the conductive particles with insulating particles, the polymer compound or the compound to be the polymer compound is (meth) It preferably has at least one reactive functional group selected from the group consisting of an acryloyl group, a glycidyl group and a vinyl group. Among these, from the viewpoint of further suppressing the detachment of the insulating particles, the polymer compound or the compound to be the polymer compound preferably has a (meth) acryloyl group.

  Specific examples of the compound having the (meth) acryloyl group include methacrylic acid, hydroxyethyl acrylate, and ethylene glycol dimethacrylate.

  Specific examples of the epoxy compound include bisphenol A type epoxy resin and resorcinol glycidyl ether.

  Specific examples of the compound having a vinyl group include styrene and vinyl acetate.

  The polymer compound preferably has a weight average molecular weight of 1000 or more. The upper limit of the weight average molecular weight of the polymer compound is not particularly limited, but the polymer compound preferably has a weight average molecular weight of 20000 or less. The weight average molecular weight indicates a value in terms of polystyrene measured by gel permeation chromatography (GPC).

  The method for forming the layer formed of the polymer compound on the surface of the insulating particles is not particularly limited. Using a polymer compound or a compound that becomes a polymer compound so as to cover at least a part of the surface of the insulating particle main body, a layer formed of the polymer compound is formed to obtain insulating particles. preferable. As an example of a method for forming a layer formed of the above polymer compound, a compound having a reactive double bond and a hydroxyl group on an insulating particle body having a reactive functional group such as a vinyl group on the surface is used as the insulating particle. Examples thereof include a method of polymerizing on the surface of the main body. However, methods other than this forming method may be used.

  The insulating particle body and the layer are preferably chemically bonded. This chemical bond includes a covalent bond, a hydrogen bond, an ionic bond, a coordination bond, and the like. Of these, a covalent bond is preferable, and a chemical bond using a reactive functional group is preferable.

  Examples of the reactive functional group that forms the chemical bond include a vinyl group, (meth) acryloyl group, silane group, silanol group, carboxyl group, amino group, ammonium group, nitro group, hydroxyl group, carbonyl group, and thiol group. Sulfonic acid group, sulfonium group, boric acid group, oxazoline group, pyrrolidone group, phosphoric acid group and nitrile group. Of these, a vinyl group and a (meth) acryloyl group are preferable.

  From the viewpoint of further suppressing the detachment of the insulating particles and further improving the insulation reliability in the connection structure, it is possible to use an insulating particle body having a reactive functional group on the surface as the insulating particle body. preferable. From the viewpoint of further suppressing the detachment of the insulating particles and further improving the insulation reliability in the connection structure, the insulating particles subjected to surface treatment using a compound having a reactive functional group as the insulating particle main body. It is preferable to use a particle body. From the viewpoint of further suppressing the detachment of the insulating particles and further improving the insulation reliability in the connection structure, the insulating particle main body having a reactive functional group on the surface, the polymer compound, or the polymer compound And the layer formed of the polymer compound is chemically bonded to the reactive functional group on the surface of the insulating particle body using the compound to form the insulating particle body and the layer. It is preferable that the insulating particles that are chemically bonded are obtained.

  Examples of the reactive functional group on the surface of the insulating particle body include a (meth) acryloyl group, a glycidyl group, a hydroxyl group, a vinyl group, and an amino group. The reactive functional group on the surface of the insulating particle body is at least one reactive functional group selected from the group consisting of a (meth) acryloyl group, a glycidyl group, a hydroxyl group, a vinyl group, and an amino group. Is preferred.

  Examples of the compound (surface treatment substance) for introducing the reactive functional group onto the surface of the insulating particle body include a compound having a (meth) acryloyl group, a compound having an epoxy group, and a compound having a vinyl group. It is done.

  As a compound (surface treatment substance) for introducing a vinyl group as the reactive functional group onto the surface of the insulating particle body, a silane compound having a vinyl group, a titanium compound having a vinyl group, and a vinyl group are used. The phosphoric acid compound etc. which have are mentioned. The surface treatment substance is preferably a silane compound having a vinyl group. Examples of the silane compound having a vinyl group include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriacetoxysilane, and vinyltriisopropoxysilane.

  As a compound (surface treatment substance) for introducing the (meth) acryloyl group which is the reactive functional group onto the surface of the insulating particle main body, a silane compound having a (meth) acryloyl group and a (meth) acryloyl group And a phosphoric acid compound having a (meth) acryloyl group. The surface treatment substance is also preferably a silane compound having a (meth) acryloyl group. Examples of the silane compound having a (meth) acryloyl group include (meth) acryloxypropyltriethoxysilane, (meth) acryloxypropyltrimethoxysilane, (meth) acryloxypropyltridimethoxysilane, and the like.

  The conductive particle body with insulating particles can be obtained by arranging a plurality of insulating particles on the surface of the conductive particles having at least the conductive portion on the surface. It is preferable that the insulating particles are not formed by friction by mixing using the insulating particle main body and the polymer compound or the compound to be the polymer compound. Moreover, it is preferable that the surface of the insulating particle body is not covered with the layer using a hybridization method. When insulating particles are formed using friction by mixing or a hybridization method, the layer is easily detached from the surface of the insulating particle body. In addition, the fragments of the layer formed during kneading easily adhere to the surface of the insulating particles. For this reason, the layer and the fragments of the layer detached on the outer surface of the conductive part of the conductive particles with insulating particles tend to adhere, and the conduction reliability in the connection structure tends to decrease. In addition, when insulating particles are formed using friction by mixing or a hybridization method, formation of a film formed of a compound having an alkyl group having 6 to 22 carbon atoms and a reactive monomer is inhibited. Sometimes. Therefore, from the viewpoint of further suppressing the detachment of the insulating particles and further increasing the insulation reliability and conduction reliability in the connection structure, it is preferable that the insulating particles are not formed by friction due to mixing. It is preferable not to use a hybridization method.

  When the insulating particles are obtained, the amount of the polymer compound or the compound that becomes the polymer is preferably 30 parts by weight or more, more preferably 50 parts by weight or more, with respect to 100 parts by weight of the insulating particle body. , Preferably 500 parts by weight or less, more preferably 300 parts by weight or less. A favorable layer can be formed as the usage-amount of the said high molecular compound is more than the said minimum and below the said upper limit.

  Examples of the method for attaching the insulating particles to the conductive particles and the outer surface of the conductive part include a chemical method and a physical or mechanical method. Examples of the chemical method include an interfacial polymerization method, a suspension polymerization method in the presence of particles, and an emulsion polymerization method. Examples of the physical or mechanical method include spray drying, hybridization, electrostatic adhesion, spraying, dipping, and vacuum deposition. However, since the hybridization method tends to cause the detachment of the insulating particles, the method of attaching the insulating particles to the outer surfaces of the conductive particles and the conductive part is a method other than the hybridization method. It is preferable. In particular, a method in which the insulating particles are attached to the outer surface of the conductive portion via a chemical bond is preferable because the insulating particles are difficult to be detached.

  In the conductive particles with insulating particles according to the present invention, the insulating particles are preferably not attached to the surface of the conductive particles by a hybridization method. In the step of obtaining the conductive particle body with insulating particles, it is preferable that the insulating particles are not attached to the surface of the conductive particles by a hybridization method.

  As shown in FIG. 5, in the conventional conductive particles 101 with insulating particles using the hybridization method, the surface of the conductive particles 102 has a portion 102b other than the portion 102a to which the insulating particles 103 are attached. Also, the polymer compound 104 adheres. This is because in the hybridization method, a compressive shear force is applied, the insulating particles are repeatedly attached and detached, and the insulating particles are gradually attached. The layer formed of the polymer compound of the insulating particles is peeled off by the compressive shearing force, and the peeled polymer compound is attached to a portion other than the portion where the insulating particles are attached on the surface of the conductive particles. The polymer compound adhering to the portion other than the portion to which the insulating particles adhere on the surface of the conductive particles increases the volume resistivity of the conductive particles or decreases the connection resistance between the electrodes. Further, even when the surface of the conductive particles 101 with insulating particles shown in FIG. 5 is coated with a coating, the conductivity is low and the connection resistance between the electrodes tends to be low.

  The following method is mentioned as an example of the method of making an insulating particle adhere to the outer surface of the said electroconductive particle and the said electroconductive part.

  First, the conductive particles are put in 3 L of a solvent such as water, and the insulating particles are gradually added while stirring. After sufficiently stirring, the conductive particles with insulating particles are separated and dried by a vacuum dryer or the like to obtain conductive particles with insulating particles.

  The conductive part preferably has a reactive functional group capable of reacting with insulating particles on the surface, and preferably has a reactive functional group capable of reacting with the coating. The insulating particles preferably have a reactive functional group capable of reacting with the conductive portion on the surface, and preferably have a reactive functional group capable of reacting with the coating. The coating preferably has a reactive functional group capable of reacting with the conductive portion on the surface, and preferably has a functional group capable of reacting with the insulating particles. By these reactive functional groups, it becomes difficult for the insulating particles to be unintentionally detached from the surface of the conductive particles, and further, the coating film is difficult to peel from the surfaces of the conductive particles and the surfaces of the insulating particles. Furthermore, the outer surface of the conductive portion can be sufficiently covered with the coating, and the surface of the insulating particles can be sufficiently covered with the coating.

  As the reactive functional group, an appropriate group is selected in consideration of reactivity. Examples of the reactive functional group include a hydroxyl group, a vinyl group, and an amino group. Since the reactivity is excellent, the reactive functional group is preferably a hydroxyl group. The conductive particle body with insulating particles preferably has a hydroxyl group in at least a part of the surface. The conductive particles preferably have a hydroxyl group on the surface. The insulating particles preferably have a hydroxyl group on the surface. The coating preferably has a hydroxyl group on the surface.

  When there are hydroxyl groups on the surface of the insulating particles and the surface of the conductive particles, the adhesion force between the insulating particles and the conductive particles is appropriately increased by the dehydration reaction.

  Examples of the compound having a hydroxyl group include a P—OH group-containing compound and a Si—OH group-containing compound. Examples of the compound having a hydroxyl group for introducing a hydroxyl group on the surface of the insulating particles include a P—OH group-containing compound and a Si—OH group-containing compound.

  Specific examples of the P-OH group-containing compound include acid phosphooxyethyl methacrylate, acid phosphooxypropyl methacrylate, acid phosphooxypolyoxyethylene glycol monomethacrylate, and acid phosphooxypolyoxypropylene glycol monomethacrylate. As for the said P-OH group containing compound, only 1 type may be used and 2 or more types may be used together.

  Specific examples of the Si-OH group-containing compound include vinyltrihydroxysilane and 3-methacryloxypropyltrihydroxysilane. As for the said Si-OH group containing compound, only 1 type may be used and 2 or more types may be used together.

  For example, insulating particles having a hydroxyl group on the surface can be obtained by a treatment using a silane coupling agent. Examples of the silane coupling agent include hydroxytrimethoxysilane.

(Method for producing conductive particles with insulating particles)
The manufacturing method of the electroconductive particle with an insulating particle which concerns on this invention comprises the process of forming a film so that the surface of the electroconductive particle main body with an insulating particle may be coat | covered. The insulating property having a first coating portion covering the conductive particles and a second coating portion covering the surface of the insulating particles, and having a thickness in the first coating portion. The coating is formed so that the ratio of the particles to the average particle diameter is 2/3 or more and 3 or less.

  In the method for producing conductive particles with insulating particles according to the present invention, a compound (compound A) having an alkyl group having 6 to 22 carbon atoms and a reactive monomer are used on the surface of the conductive particle body with insulating particles. It is preferable to form a coating so as to cover the surface of the insulating particle body.

  The method for forming a film on the surface of the conductive particle body with insulating particles using the compound A and the reactive monomer is not particularly limited, and the compound A is formed on the surface of the conductive particle body with insulating particles. Examples of the method include a method in which a reactive monomer is polymerized using a polymerizable initiator and then coated.

  The solvent in the solution containing the compound A and reactive monomer is preferably water. The solvent in the solution containing the compound A may contain tetrahydrofuran and organic solvents such as alcohols such as methanol, ethanol and propanol. After making the said solution adhere to the surface of the electroconductive particle main body with an insulating particle, a solvent is removed as needed.

  Content of the said compound A and reactive monomer in the solution containing the said compound A and reactive monomer is suitably adjusted so that a desired film may be obtained.

  For example, when a reactive functional group capable of reacting with the compound A is present on the outer surface of the conductive part or the surface of the insulating particles, the reactive functional group is reacted with the compound A, and the conductive The compound A can be chemically bonded to the outer surface of the part and the surface of the insulating particles.

  Compound having conductive particle body with insulating particles having hydroxyl group in at least a part of the surface, and hydroxyl group on the surface of conductive particle body with insulating particle having a C 6-22 alkyl group having a hydroxyl group It is preferable to form a film so as to coat the surface of the conductive particle body with insulating particles by reacting (hereinafter also referred to as compound A1). Further, the conductive particles have a hydroxyl group on the surface, and the film is formed so as to cover the surface of the conductive particle body with insulating particles by reacting the compound A1 with the hydroxyl group on the surface of the conductive particle. It is preferable. It is preferable that the insulating particles have a hydroxyl group on the surface, and the coating is formed so as to cover the surface of the conductive particle body with insulating particles by reacting the compound A1 with the hydroxyl group on the surface of the insulating particles. . Furthermore, the surface of the conductive particles and the surface of the insulating particles each have a hydroxyl group, and the compound A1 is reacted with the hydroxyl groups on the surface of the conductive particles and the surface of the insulating particles, thereby conducting the conductive particles with insulating particles. It is preferable to form a coating so as to cover the surface of the main body. By forming a film in these preferred embodiments, the outer surface of the conductive portion can be sufficiently covered with the film, and the surface of the insulating particles can be sufficiently covered with the film. Accordingly, rust is more unlikely to occur in the conductive portion, the coating is difficult to peel off, and the insulating particles are not easily detached unintentionally.

  The surface of the conductive particles and the surface of the insulating particles may each be coated with a compound having a reactive functional group. The surface of the conductive particles and the surface of the insulating particles 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 into the surface of the conductive particle, the carboxyl group may be chemically bonded to a functional group on the surface of the insulating particle through a polymer electrolyte such as polyethyleneimine.

(Conductive material)
The conductive material according to the present invention includes the conductive particles with insulating particles of the present invention and a binder resin, or the conductive material with insulating particles obtained by the method for producing conductive particles with insulating particles of the present invention. Particles and a binder resin. The conductive particles are 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 of electrodes. The conductive material is preferably a circuit connection material.

  When the conductive particles with insulating particles are used, since the surfaces of the insulating particles and the conductive particles are covered with a specific coating, the conductive particles with insulating particles are dispersed in the binder resin. In some cases, it is difficult for the insulating particles to be detached from the surface of the conductive particles.

  The binder resin is not particularly limited. In general, an insulating resin is used as the binder resin. The binder resin preferably includes a thermoplastic component (thermoplastic compound) or a curable component, and more preferably includes a curable component. Examples of the curable component include a photocurable component and a thermosetting component. It is preferable that the said photocurable component contains a photocurable compound and a photoinitiator. The thermosetting component preferably contains a thermosetting compound and a thermosetting agent. Examples of the binder resin include vinyl resins, thermoplastic resins, curable resins, thermoplastic block copolymers, and elastomers. As for the said binder resin, only 1 type may be used and 2 or more types may be used together.

  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. Examples of the curable resin include an epoxy resin, a urethane resin, a polyimide resin, and an unsaturated polyester resin. 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 a styrene-butadiene-styrene block copolymer, a styrene-isoprene-styrene block copolymer, a hydrogenated product of a styrene-butadiene-styrene block copolymer, and a styrene-isoprene. -Hydrogenated product of a styrene block copolymer. Examples of the elastomer include styrene-butadiene copolymer rubber and acrylonitrile-styrene block copolymer rubber.

  In addition to the conductive particles with insulating particles and the binder resin, the conductive material includes, for example, a filler, an extender, a softener, a plasticizer, a polymerization catalyst, a curing catalyst, a colorant, an antioxidant, and heat stability. Various additives such as an agent, a light stabilizer, an ultraviolet absorber, a lubricant, an antistatic agent and a flame retardant may be contained.

  The conductive material according to the present invention can be used as a conductive paste or a conductive film. When the conductive material according to the present invention is used as a conductive film, a film not including conductive particles may be laminated on the conductive film including the conductive particles. The conductive paste is preferably an anisotropic conductive paste. The conductive film is preferably an anisotropic conductive film.

  The conductive material according to the present invention is preferably a conductive paste, and more preferably an anisotropic conductive paste. Conductive pastes such as anisotropic conductive pastes are excellent in handleability and circuit fillability. When a conductive paste is obtained, a relatively large force is applied to the conductive particles with insulating particles, but it is possible to prevent the insulating particles from being detached from the surface of the conductive particles due to the presence of the coating film.

  The content of the binder resin in 100% by weight of the conductive material 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, preferably It is 99.99 weight% or less, More preferably, it is 99.9 weight% or less. When the content of the binder resin is not less than the above lower limit and not more than the above upper limit, the conductive particles are efficiently arranged between the electrodes, and the connection reliability of the connection target member connected by the conductive material is further increased.

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

(Connection structure)
By using the conductive particles with insulating particles of the present invention or by using a conductive material containing the conductive particles with insulating particles and a binder resin, a connection structure is obtained by connecting the connection target members. Can do. Furthermore, using the conductive particles with insulating particles obtained by the method for producing conductive particles with insulating particles of the present invention, or using a conductive material containing the conductive particles with insulating particles and a binder resin. By connecting the connection target members, a connection structure can be obtained.

  The connection structure includes a first connection object member, a second connection object member, and a connection part that electrically connects the first and second connection object members, and a material for the connection part. Are conductive particles with insulating particles, or a connection structure that is a conductive material including the conductive particles with insulating particles and a binder resin. It is preferable that the connection portion is formed of the conductive particles with insulating particles or a connection structure formed of a conductive material including the conductive particles with insulating particles and a binder resin. In the case where conductive particles with insulating particles are used, the connecting portion itself is formed of conductive particles with insulating particles. That is, the first and second connection target members are electrically connected by the conductive particles in the conductive particles with insulating particles.

  FIG. 4 is a cross-sectional view schematically showing a connection structure using the conductive particles 1 with insulating particles shown in FIG.

  A connection structure 81 shown in FIG. 4 includes a first connection target member 82, a second connection target member 83, and a connection portion 84 connecting the first and second connection target members 82 and 83. Prepare. The connecting portion 84 is formed of a conductive material including the conductive particles 1 with insulating particles and a binder resin. In FIG. 4, the conductive particles 1 with insulating particles are schematically shown for convenience of illustration. Instead of the conductive particles 1 with insulating particles, conductive particles 21 and 41 with insulating particles may be used.

  The first connection target member 82 has a plurality of first electrodes 82a on the surface (upper surface). The second connection target member 83 has a plurality of second electrodes 83a on the front surface (back surface). The 1st electrode 82a and the 2nd electrode 83a are electrically connected by the electroconductive particle 11 in the electroconductive particle 1 with one or some insulating particle. Therefore, the first and second connection target members 82 and 83 are electrically connected by the conductive particles 1 with insulating particles.

The manufacturing method of the connection structure is not particularly limited. As an example of a method of manufacturing a connection structure, a method of placing the conductive material between a first connection target member and a second connection target member to obtain a laminate, and then heating and pressurizing the laminate Etc. The pressure of the said pressurization is about 9.8 * 10 < ⁴ > -4.9 * 10 < ⁶ > Pa. The temperature of the said heating is about 120-220 degreeC.

  When the laminate is heated and pressed, the insulating particles 15 existing between the conductive particles 11 and the first and second electrodes 82a and 83a can be eliminated. For example, during the heating and pressurization, the insulating particles 15 existing between the conductive particles 11 and the first and second electrodes 82a and 83a are melted or deformed, The surface of the conductive particles 11 is partially exposed. In addition, since a large force is applied during the heating and pressurization, some of the insulating particles 15 are peeled off from the surface of the conductive particles 11, and the surface of the conductive particles 11 is partially exposed. Sometimes. The portion where the surface of the conductive particle 11 is exposed contacts the first and second electrodes 82a and 83a, so that the first and second electrodes 82a and 83a are electrically connected through the conductive particle 11. it can.

  Specific examples of the connection target member include electronic components such as semiconductor chips, capacitors, and diodes, and electronic components such as printed boards, flexible printed boards, glass epoxy boards, and glass boards. The conductive material is in a paste form, and is preferably applied on the connection target member in a paste state. The conductive particles with insulating particles and the conductive material are preferably used for connection of a connection target member that is an electronic component. The connection target member is preferably an electronic component. The conductive particles with insulating particles are preferably used for electrical connection of electrodes in an electronic component.

  Examples of the electrode provided on the connection target member include metal electrodes such as a gold electrode, a nickel electrode, a tin electrode, an aluminum electrode, a copper electrode, a silver electrode, a molybdenum electrode, and a tungsten electrode. When the connection object 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 the metal oxide layer may be sufficient. Examples of the material for the metal oxide layer include indium oxide doped with a trivalent metal element and zinc oxide doped with a trivalent metal element. Examples of the trivalent metal element include Sn, Al, and Ga.

  Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples. The present invention is not limited only to the following examples.

Example 1
Divinylbenzene resin particles (average particle size of 2.8 μm) were prepared.

  The resin particles 10g were etched and then washed with water. Next, palladium sulfate was added to the resin particles to adsorb palladium ions to the resin particles. The resin particles to which palladium was attached were stirred and dispersed in 300 mL of ion exchange water for 3 minutes to obtain a dispersion. Next, 1 g of metallic nickel particle slurry (average particle size 200 nm) was added to the dispersion over 3 minutes to obtain resin particles to which the core substance was adhered. A nickel layer was formed by electroless nickel plating on the surface of the resin particles to which the core substance adhered. In this way, conductive particles were obtained in which the core material was adhered to the surface of the resin particles, and the surfaces of the resin particles and the core material were covered with the nickel layer. The average particle diameter of the conductive particles was 3 μm, and the thickness of the conductive layer was 0.2 μm. The conductive particles had protrusions having an average height of 0.25 μm on the outer surface of the nickel layer.

  Moreover, the surface of the silica particle (average particle diameter 200nm) produced using the sol-gel method was coat | covered with hydroxytriethoxysilane, and the insulating particle which has a hydroxyl group on the surface was obtained. The insulating particles were dispersed in 30 mL of pure water to obtain a dispersion containing insulating particles.

  In a 1 L separable flask, 250 mL of pure water, 50 mL of ethanol, and 15 parts by weight of the conductive particles were put, and stirred sufficiently to obtain a liquid containing conductive particles. A dispersion containing insulating particles was dropped into the liquid containing conductive particles over 10 minutes while applying ultrasonic waves. Then, it filtered and it was made to dry at 100 degreeC with a vacuum dryer for 8 hours, and the electroconductive particle main body with an insulating particle was obtained.

  10 parts by weight of the conductive particles with insulating particles and 0.5 part by weight of oleyl acid phosphate were placed in a mixed solution of 25 g of pure water and 25 g of ethanol, and stirred at 50 ° C. for 1 hour. After heating to 70 ° C., mixing of 2 parts by weight of methyl methacrylate, 0.5 part by weight of initiator (“V-50” manufactured by Wako Pure Chemical Industries, Ltd.), 10 parts by weight of pure water and 10 parts by weight of ethanol The solution was added dropwise over 2 hours, followed by stirring for 5 hours. Then, it is filtered and dried at 100 ° C. for 8 hours by a vacuum drier. Conductive particles with insulating particles having a film formed of the oleyl acid phosphate and methyl methacrylate on the surface of the conductive particle body with insulating particles. Sex particles were obtained. Using a focused ion beam, a thin film section of the obtained conductive particles was prepared, and an energy dispersive X-ray analyzer (“JEM-2010FEF” manufactured by JEOL Ltd.) was used with a transmission electron microscope FE-TEM ( By EDS), the state of the film formed with oleyl acid phosphate and methyl methacrylate was observed, and the thickness of the film was measured. The coating covered the surface of the conductive particles and the surface of the insulating particles. The first coating portion covering the surface of the conductive particles and the second coating portion covering the surface of the insulating particles were continuous. The thickness of the 1st film part and the 2nd film part was the same. The ratio (thickness / average particle diameter) of the thickness of the first coating portion to the average particle diameter of the insulating particles was 1. All of the plurality of insulating particles were in contact with the conductive particles. In the conductive particles with insulating particles, all the insulating particles were not exposed.

(Example 2)
The same conductive particles as those of Example 1 (average particle diameter 3 μm, conductive layer thickness 0.2 μm) were prepared.

  Moreover, the surface of the silica particle (average particle diameter 200nm) produced using the sol-gel method was coat | covered with vinyltriethoxysilane, and the insulating particle which has a vinyl group on the surface was obtained as an insulating particle main body. Specifically, 10 parts by weight of silica particles were dispersed in 400 mL of a liquid in which water and ethanol were mixed at a weight ratio of 1: 9 using a three-one motor to obtain a first dispersion. Next, 0.1 part by weight of vinyltriethoxysilane was dispersed in 100 mL of a liquid in which water and ethanol were mixed at a weight ratio of 1: 9 to obtain a second dispersion. Thereafter, the second dispersion was dropped into the first dispersion over 10 minutes to obtain a mixed solution. After the dropwise addition, the resulting mixture was stirred for 30 minutes. Then, after filtering a liquid mixture and drying at 100 degreeC for 2 hours, the insulating particle main body was obtained by sieving with a sieve.

  In 200 mL of water, 1 part by weight of the insulating particle main body, 0.22 part by weight of methyl methacrylate, 0.05 part by weight of ethylene glycol dimethacrylate, and an initiator as a polymer compound covering the insulating particle main body (V-50 manufactured by Wako Pure Chemical Industries, Ltd.) 0.5 parts by weight was heated to 70 ° C. with sufficient stirring with a three-one motor and held at 70 ° C. for 6 hours to polymerize the monomer. .

  Then, it cooled, solid-liquid separation was performed twice with the centrifuge, the excess monomer was removed by washing | cleaning, and the insulating particle by which the whole surface was coat | covered with the high molecular compound was obtained. Next, the obtained insulating particles were dispersed in 30 mL of pure water to obtain a dispersion of insulating particles.

  A 1 L separable flask was charged with 250 mL of pure water, 50 mL of ethanol, and 15 parts by weight of the conductive particles, and stirred sufficiently to obtain a liquid containing conductive particles. To the liquid containing the conductive particles, the dispersion of the insulating particles was dropped over 10 minutes while applying ultrasonic waves, and then the temperature was raised to 40 ° C. and stirred for 1 hour. Then, it filtered and it was made to dry at 100 degreeC with a vacuum dryer for 8 hours, and the electroconductive particle main body with an insulating particle was obtained.

  Except having used the obtained electroconductive particle main body with an insulating particle, it carried out similarly to Example 1, and obtained the electroconductive particle with an insulating particle. The coating covered the surface of the conductive particles and the surface of the insulating particles. The first coating portion covering the surface of the conductive particles and the second coating portion covering the surface of the insulating particles were continuous. The thickness of the 1st film part and the 2nd film part was the same. The ratio (thickness / average particle diameter) of the thickness of the first coating portion to the average particle diameter of the insulating particles was 1. All of the plurality of insulating particles were in contact with the conductive particles. In the conductive particles with insulating particles, all the insulating particles were not exposed.

(Example 3)
Insulation was performed in the same manner as in Example 1 except that the metal nickel particle slurry (average particle size 200 nm) was changed to metal nickel particle slurry (average particle size 50 nm) and the average height of the protrusions was changed to 0.06 μm. Conductive particles with conductive particles were obtained.

Example 4
Insulation was conducted in the same manner as in Example 1 except that the metal nickel particle slurry (average particle diameter 200 nm) was changed to metal nickel particle slurry (average particle diameter 70 nm) and the average height of the protrusions was changed to 0.08 μm. Conductive particles with conductive particles were obtained.

(Example 5)
Insulation was performed in the same manner as in Example 1 except that the metal nickel particle slurry (average particle diameter 200 nm) was changed to metal nickel particle slurry (average particle diameter 400 nm) and the average height of the protrusions was changed to 0.45 μm. Conductive particles with conductive particles were obtained.

(Example 6)
Conductive particles with insulating particles were obtained in the same manner as in Example 1, except that oleyl acid phosphate was changed to monooctyl phosphate.

(Example 7)
Conductive particles with insulating particles were obtained in the same manner as in Example 1 except that oleyl acid phosphate was changed to monododecyl phosphate.

(Example 8)
Conductive particles with insulating particles were obtained in the same manner as in Example 1 except that oleyl acid phosphate was changed to monohexadecyl phosphate.

Example 9
Conductive particles with insulating particles were obtained in the same manner as in Example 1 except that oleyl acid phosphate was changed to hexyltriethoxysilane.

(Example 10)
Conductive particles with insulating particles were obtained in the same manner as in Example 1 except that oleyl acid phosphate was changed to octyltriethoxysilane.

(Example 11)
Conductive particles with insulating particles were obtained in the same manner as in Example 1 except that oleyl acid phosphate was changed to dodecyltriethoxysilane.

(Example 12)
A dispersion containing insulating particles was obtained in the same manner as in Example 2 except that the polymer compound was changed to 2.5 parts by weight of methacrylic acid and 1.2 parts by weight of divinylbenzene. The average particle diameter of the insulating particles coated with the polymer compound in the state of the dispersion of the insulating particles was 335 nm.

  Conductive particles with insulating particles were obtained in the same manner as in Example 1 except that the obtained dispersion containing insulating particles was used as the dispersion containing insulating particles.

(Example 13)
The surface of the silica particles was coated with methacryloxypropyltriethoxysilane to obtain insulating particles having a methacryloyl group on the surface as the insulating particle body, and the compound to be a polymer compound was 2.2 parts by weight of vinyl acetate. A dispersion containing insulating particles was obtained in the same manner as in Example 2 except that the amount was changed to 1.0 part by weight of N, N-methylenebisacrylamide.

  The average particle diameter of the insulating particles covered with the polymer compound in the state of the dispersion of the insulating particles was 326 nm.

  Conductive particles with insulating particles were obtained in the same manner as in Example 1 except that the obtained dispersion containing insulating particles was used as the dispersion containing insulating particles.

(Example 14)
As conductive particles, nickel powder (100 nm) is attached as a core substance to the surface of divinylbenzene resin particles, and a nickel plating layer (conductive layer) is formed on the surface of divinylbenzene particles to which nickel powder is attached. Conductive particles with insulating particles were obtained in the same manner as in Example 1 except that the conductive particles (average particle size: 3.03 μm, conductive layer thickness: 0.21 μm) were used.

(Example 15)
A dispersion containing insulating particles was obtained in the same manner as in Example 2 except that the polymer compound was changed to 0.4 parts by weight of methacrylic acid and 0.05 parts by weight of ethylene glycol dimethacrylate. Obtained.

  The average particle diameter of the insulating particles coated with the polymer compound in the state of the dispersion of the insulating particles was 248 nm.

  Conductive particles with insulating particles were obtained in the same manner as in Example 1 except that the obtained dispersion containing insulating particles was used as the dispersion containing insulating particles.

(Example 16)
Conductive particles with insulating particles were obtained in the same manner as in Example 2 except that the conductive particle body with insulating particles was obtained using the hybridization method. In the hybridization method, insulating particles and conductive particles are mixed using a hybridizer (“NHS series” manufactured by Nara Machinery Co., Ltd.) under the conditions of 50 ° C. and 12,000 revolutions / minute to obtain insulating properties. Conductive particles with particles were obtained.

(Example 17)
The amount of the material used for forming the coating was changed, and the thickness in the first coating portion was changed to 0.70 times (140 nm) the average particle diameter of the insulating particles in the same manner as in Example 1. As a result, conductive particles with insulating particles were obtained.

(Example 18)
The amount of the material used for forming the coating was changed, and the thickness in the first coating was changed to 2.5 times (500 nm) the average particle diameter of the insulating particles, as in Example 1. As a result, conductive particles with insulating particles were obtained.

(Example 19)
Insulation was performed in the same manner as in Example 1 except that the amount of the material used for forming the coating was changed and the thickness of the first coating was changed to 3 times the average particle diameter (600 nm) of the insulating particles. Conductive particles with conductive particles were obtained.

(Example 20)
As conductive particles, silica powder (average particle diameter 200 nm) is attached as a core substance to the surface of divinylbenzene resin particles, and a nickel plating layer (conductive layer) is formed on the surface of divinylbenzene particles to which silica powder is attached. ) Was used in the same manner as in Example 1 except that conductive particles (average particle diameter of 3 μm, conductive layer thickness of 0.2 μm) formed thereon were obtained.

(Example 21)
Nickel nanopowder was changed so that the nanopowder (200 nm) generated in the system during the plating reaction was attached to the surface of the divinylbenzene resin particles without adding metallic nickel particles as the core material as conductive particles. Example 1 except that conductive particles (average particle diameter 3 μm, conductive layer thickness 0.2 μm) in which a nickel plating layer (conductive layer) is formed on the surface of the divinylbenzene particles to which the body is attached are used. Similarly, conductive particles with insulating particles were obtained.

(Comparative Example 1)
The electroconductive particle with an insulating particle which is the electroconductive particle main body with an insulating particle obtained in Example 1. That is, in Comparative Example 1, the conductive particle main body with insulating particles obtained in Example 1 was not formed on the conductive particle main body with insulating particles obtained in Example 1, and the insulating particle was used as an insulating particle. The attached conductive particles were used for evaluation described later.

(Comparative Example 2)
Conductive particles (average particle diameter: 3 μm, conductive layer thickness: 0.2 μm) having a metal layer on which nickel plating layers are formed on the surface of divinylbenzene resin particles were prepared.

  10 parts by weight of the conductive particles with insulating particles and 0.5 part by weight of oleyl acid phosphate were placed in a mixed solution of 25 g of pure water and 25 g of ethanol, and stirred at 50 ° C. for 1 hour. Then, it filtered and dried at 100 degreeC with the vacuum dryer for 8 hours, and obtained the electroconductive particle which has the film formed with the said monohexyl phosphate on the surface of electroconductive particle. The coating covered the surface of the conductive particles.

  Moreover, the surface of the silica particle (average particle diameter 200nm) produced using the sol-gel method was coat | covered with hydroxytriethoxysilane, and the insulating particle which has a hydroxyl group on the surface was obtained. The insulating particles were dispersed in 30 mL of pure water to obtain a dispersion containing insulating particles.

  In a 1 L separable flask, 250 mL of pure water, 50 mL of ethanol, and 15 parts by weight of the conductive particles were put, and stirred sufficiently to obtain a liquid containing conductive particles. A dispersion containing insulating particles was dropped into a liquid containing conductive particles having a film over 10 minutes while applying ultrasonic waves. Then, it filtered and it was made to dry at 100 degreeC with a vacuum dryer for 8 hours, and the electroconductive particle with an insulating particle was obtained. In the obtained conductive particles with insulating particles, the coating did not cover the surfaces of the insulating particles.

(Comparative Example 3)
The amount of the material used for forming the coating was changed, and the thickness in the first coating was changed to 0.60 times (120 nm) the average particle diameter of the insulating particles in the same manner as in Example 1. As a result, conductive particles with insulating particles were obtained.

(Comparative Example 4)
Conductive particles with insulating particles were obtained in the same manner as in Example 1 except that no protrusion was formed.

(Comparative Example 5)
The amount of the material used for forming the coating was changed, and the thickness in the first coating was changed to 3.5 times (700 nm) the average particle diameter of the insulating particles, as in Example 1. As a result, conductive particles with insulating particles were obtained.

(Comparative Examples 6 and 7)
Insulation was carried out in the same manner as in Example 1 except that the average particle diameter of the metal nickel particle slurry (average particle diameter 200 nm) used as the core substance was changed and the average height of the protrusions was changed as shown in Table 1 below. Conductive particles with conductive particles were obtained.

(Evaluation)
Preparation of anisotropic conductive paste:
The conductive particles with insulating particles were added to “Strectbond XN-5A” manufactured by Mitsui Chemicals so that the content was 10% by weight, and dispersed to obtain an anisotropic conductive paste.

Fabrication of connection structure:
A transparent glass substrate having an ITO electrode pattern with an L / S of 30 μm / 30 μm formed on the upper surface was prepared. Further, a semiconductor chip was prepared in which a copper electrode pattern having L / S of 30 μm / 30 μm was formed on the lower surface.

  On the transparent glass substrate, the obtained anisotropic conductive paste was applied to a thickness of 30 μm to form an anisotropic conductive paste layer. Next, the semiconductor chip was stacked on the anisotropic conductive paste layer so that the electrodes face each other. Then, while adjusting the temperature of the head so that the temperature of the anisotropic conductive paste layer becomes 185 ° C., a pressure heating head is placed on the upper surface of the semiconductor chip, and a pressure of 0.5 MPa is applied to apply the anisotropic conductive paste. The layer was fully cured at 185 ° C. to obtain a connection structure.

(1) Evaluation of conduction reliability (between upper and lower electrodes)
The connection resistance between the upper and lower electrodes of the obtained connection structure was measured by a four-terminal method. The average value of the two connection resistances was calculated. Note that the connection resistance can be obtained by measuring the voltage when a constant current is passed from the relationship of voltage = current × resistance. The conduction reliability (connection resistance) was determined according to the following criteria.

[Judgment criteria for conduction reliability]
○○: Connection resistance is 2.0Ω or less ○: Connection resistance exceeds 2.0Ω, 3.0Ω or less △: Connection resistance exceeds 3.0Ω, 4.0Ω or less Δ △: Connection resistance is 4.0Ω Exceeding 5.0Ω or less ×: Connection resistance exceeds 5.0Ω

(2) Evaluation of insulation reliability (between adjacent electrodes in the horizontal direction)
In the obtained connection structure, the presence or absence of leakage between adjacent electrodes was evaluated by measuring resistance with a tester. Insulation reliability was judged according to the following criteria.

[Criteria for insulation reliability]
○: Resistance exceeds 700 MΩ and it is determined that there is no leak. Δ: Resistance exceeds 500 MΩ and is 700 MΩ or less, and it is determined that there is no leakage. X: Resistance is 500 MΩ or less and it is determined that there is a leak.

(3) Rust prevention The connection structure was left under conditions of 85 ° C. and relative humidity 85%. After 100 hours from the start of standing, the connection resistance between the electrodes was measured by the 4-terminal method in the same manner as described above. Rust prevention was evaluated by evaluating how much the average value of connection resistance (after leaving) rises compared to the average value of connection resistance (before leaving) at the time of evaluation of the above-mentioned conduction reliability. .

[Criteria for rust prevention]
○: The average value of the connection resistance (after leaving) is less than 150% of the average value of the connection resistance (before leaving). ×: The connection resistance (after leaving) of the average value of the connection resistance (before leaving). The average value is 150% or more

(4) Insulation prevention property of insulating particles before conductive connection In the anisotropic conductive paste, it was observed whether or not the insulating particles were detached from the surface of the conductive particles. The anti-detachment property of the insulating particles was determined according to the following criteria.

[Decision criteria for desorption prevention]
○: The ratio of the insulating particles detached from the surface of the conductive particles is extremely small (the number ratio of the detached insulating particles is less than 10%).
Δ: There are a few insulating particles detached from the surface of the conductive particles (number ratio of the detached insulating particles is 10% or more and less than 40%)
X: There are many insulating particles detached from the surface of the conductive particles (number ratio of detached insulating particles is 40% or more)

(5) Insulative particle detachability during conductive connection In the connection structure, the insulating particle is sandwiched between the electrode and the conductive particle without or after detachment from the surface of the conductive particle. It was evaluated whether or not insulating particles exist.

[Judgment criteria for detachability of insulating particles]
○: There are no insulating particles sandwiched between the electrode and the conductive particles. Δ: There are a few insulating particles sandwiched between the electrode and the conductive particles. There are insulating particles sandwiched between the particles

  The results are shown in Table 1 below. In Table 1 below, the ratio (thickness / average particle diameter) indicates the ratio of the thickness of the coating to the average particle diameter of the insulating particles. In the evaluation of (1) conduction reliability, the specific value of the connection resistance was lower in Example 18 than in Example 19.

DESCRIPTION OF SYMBOLS 1 ... Conductive particle with insulating particle 2 ... Conductive particle body with insulating particle 3 ... Coating 3a ... First coating part 3b ... Second coating part 11 ... Conductive particle 11a ... Protrusion 12 ... Base particle 13 ... Conductive layer (conductive part)
DESCRIPTION OF SYMBOLS 13a ... Protrusion 14 ... Core substance 15 ... Insulating particle 21 ... Conductive particle with insulating particle 22 ... Conductive particle body with insulating particle 31 ... Conductive particle 31a ... Protrusion 32 ... Conductive part 32a ... Protrusion 35 ... Insulating Particle 35a ... Insulating particle body 35b ... Layer 41 ... Conductive particle with insulating particle 42 ... Conductive particle body with insulating particle 43 ... Coating 43a ... First coating part 43b ... Second coating part 51 ... Conductivity Particle 51a ... Protrusion 52 ... Conductive layer 52A ... First conductive layer 52B ... Second conductive layer 52a ... Protrusion 81 ... Connection structure 82 ... First connection object member 82a ... First electrode 83 ... Second connection Target member 83a ... second electrode 84 ... connecting portion

Claims (13)

A conductive particle body with insulating particles, and a coating covering the surface of the conductive particle body with insulating particles,
The conductive particle body with insulating particles has conductive particles having at least a conductive part on the surface, and a plurality of insulating particles arranged on the surface of the conductive particles,
The conductive particles have a plurality of protrusions on the outer surface of the conductive portion;
The average height of the protrusions is 0.05 μm or more and 0.5 μm or less,
The coating has a first coating portion covering the conductive particles and a second coating portion covering the surfaces of the insulating particles,
Conductive particles with insulating particles, wherein the ratio of the thickness of the first coating portion to the average particle diameter of the insulating particles is 2/3 or more and 3 or less.   The conductive particles with insulating particles according to claim 1, wherein the insulating particles include inorganic particles, or an outer surface of the insulating particles has a glass transition temperature higher than a glass transition temperature of the coating film. .   The conductive particles with insulating particles according to claim 1 or 2, wherein an outer surface of the insulating particles has a glass transition temperature higher than a glass transition temperature of the coating film.   The conductive particles with insulating particles according to any one of claims 1 to 3, wherein 90% or more of the total number of the plurality of insulating particles is in contact with the conductive particles.   The conductive particles with insulating particles according to claim 1, wherein a plurality of the insulating particles are not exposed by being covered with the coating film.   The conductive particles with insulating particles according to claim 1, wherein the insulating particles are attached to the outer surface of the conductive part via chemical bonds.   The electroconductive particle with an insulating particle of any one of Claims 1-6 whose materials of the said film are a compound and reactive monomer which have a C6-C22 alkyl group.   The electrically-conductive material containing the electroconductive particle with an insulating particle of any one of Claims 1-7, and binder resin.   The conductive material according to claim 8, which is a conductive paste. A first connection target member;
A second connection target member;
A connection portion connecting the first connection target member and the second connection target member;
The material of the connection portion is the conductive particles with insulating particles according to any one of claims 1 to 7, or is a conductive material including the conductive particles with insulating particles and a binder resin. , Connection structure. A method for producing conductive particles with insulating particles according to any one of claims 1 to 7,
A process of forming a film by covering the surface of the conductive particle body with insulating particles having conductive particles having at least a conductive part on the surface and a plurality of insulating particles arranged on the surface of the conductive particles. With
The conductive particles have a plurality of protrusions on the outer surface of the conductive portion;
The average height of the protrusions is 0.05 μm or more and 0.5 μm or less,
The insulating particles having a thickness in the first coating portion so as to have a first coating portion covering the conductive particles and a second coating portion covering the surface of the insulating particles. The method for producing conductive particles with insulating particles, wherein the coating is formed so that the ratio of the average particle diameter to 2/3 or more and 3 or less.   12. With the insulating particles according to claim 11, comprising a step of arranging a plurality of insulating particles on the surface of the conductive particles having at least a conductive part on the surface thereof to obtain the conductive particle body with insulating particles. A method for producing conductive particles.   The process for obtaining a conductive particle body with insulating particles, wherein the insulating particles are not attached to the surface of the conductive particles by a hybridization method. Method.

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