JP6084850B2 - Conductive particles with insulating particles, conductive material, and connection structure - Google Patents

Description

  The present invention relates to, for example, conductive particles with insulating particles that can be used for electrical connection between electrodes 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, the following Patent Document 1 discloses conductive with insulating particles having conductive particles and insulating particles fixed to the surface of the conductive particles and having adhesive properties. Particles are disclosed. The insulating particles include hard particles and a polymer resin layer covering the surfaces of the hard particles. Here, a physical / mechanical hybridization method is used as an immobilization method in order to immobilize the insulating particles on the surface of the conductive particles.

  Patent Document 2 below includes conductive particles having a polar group on at least a part of a surface, and an insulating material that covers at least a part of the surface of the conductive particles and includes insulating particles. A conductive particle with insulating particles is disclosed. Specifically, the insulating material includes a polymer electrolyte that can adsorb the polar group, and inorganic oxide particles that can adsorb the polymer electrolyte. The inorganic oxide particles are insulating particles.

  Patent Document 3 below discloses conductive particles with insulating particles in which an insulating layer is formed on the surface of a conductive core having a conductive surface, and the insulating particles are embedded in the insulating layer. Has been. Patent Document 3 describes in claim 5 that “insulating fine particles are embedded in an insulating layer of a 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”.

  The following Patent Document 4 discloses conductive particles with insulating particles in which insulating particles having a particle diameter equal to or smaller than the particle diameter of the conductive particles are attached to the surface of the conductive particles. In Patent Document 4, the third page of the specification, upper left column, line 17 to upper right column, line 1 “As a method for attaching insulating particles to the surface of conductive particles, for example, conductive particles and insulating particles are used in a container. In other words, a well-known method such as a method of adhering due to the difference in the polarity of charging caused by friction is adopted.

  In the following Patent Document 5, conductive particles with conductive particles are attached to the surface of the conductive particles. The conductive particles are smaller than the conductive particles and have insulating particles that are harder than the adhesive under the connecting conditions. Particles are disclosed. The conductive particles are particles obtained by substantially covering a core material made of a polymer with a thin conductive metal layer. In Patent Document 5, in the paragraph [0021] of the specification, “as a method for immobilizing the insulating particles 3 on the heat-deformable conductive particles 5, for example, a granulation method such as a spraying method or a high-speed stirring method can be applied. As a manufacturing apparatus by such a method, it is commercially available under the trade names such as Mechano Mill (Okada Seiko), Ong Mill (Hosokawa Micron), High Predization System (Nara Machinery), Coat Mizer (Freund Sangyo), Klux System (Orient Chemical). And both are preferably applicable. "

Special table 2007-537570 gazette JP 2008-120990 A JP 2005-209491 A Japanese Patent Laid-Open No. 3-112011 JP-A-4-259766

  In the conventional conductive particles with insulating particles as 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. 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.

  In particular, as described in Patent Document 1, when a physical / mechanical hybridization method is used to immobilize the insulating particles on the surface of the conductive particles, the insulating particles are made of conductive particles. Easily detached from the surface.

  Furthermore, when the physical / mechanical hybridization method is used, the polymer resin layer of the insulating particles adheres to a portion other than the portion to which the insulating particles adhere on the surface of the conductive particles, There is also a problem that the conductivity is easily lost after the connection between the electrodes.

  Moreover, in the conductive particles with insulating particles obtained by the methods described in Patent Documents 3 to 5, the insulating particles are likely to be unintentionally detached from the surface of the conductive particles before the conductive connection, Sometimes the insulating particles are not easily detached from the surface of the conductive particles. When the conductive particles are not easily detached from the surface of the conductive particles during the conductive connection, the insulating particles may be sandwiched between the conductive particles and the electrode, or the conductive particles and the electrode may not be in contact with each other. . If the conductive particles do not contact the electrode, poor connection occurs.

  Further, in the conventional conductive particles with insulating particles as described in Patent Documents 1 and 2, at least a part of the conductive layer is exposed. For this reason, rust tends to be generated on the surface of the conductive layer by a corrosive gas in the atmosphere or a corrosive substance in the anisotropic conductive material. For this reason, high conductivity may not be sufficiently maintained over a long period of time. In addition, when electrodes are connected using conductive particles with insulating particles in which rust is generated in the conductive layer, the electrodes are not electrically connected reliably or the connection resistance between the electrodes tends to increase. Tend.

  The object of the present invention is to insulate the insulating particles from the surface of the conductive particles unintentionally from the surface of the conductive particles before the conductive connection, and to easily release the insulating particles from the surface of the conductive particles during the conductive connection. It is to provide a conductive material with a conductive particle, a method for producing a conductive particle with a conductive particle, and a conductive material and a connection structure using the conductive particle with a conductive particle.

  A limited object of the present invention is that the conductive layer is less likely to rust, can maintain high conductivity over a long period of time, and therefore, insulating particles that can improve conduction reliability when used for connection between electrodes. It is to provide a conductive material with a conductive particle, a method for producing a conductive particle with a conductive particle, and a conductive material and a connection structure using the conductive particle with a conductive particle.

  According to a wide aspect of the present invention, 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; A coating covering the surface of the conductive particle body with insulating particles, and the coating covers a first coating covering the conductive particles and a surface covering the surface of the insulating particles. There are provided conductive particles with insulating particles, and the thickness of the first coating portion is 1/2 or less of the average particle diameter of the insulating particles.

  In another specific aspect of the conductive particles with insulating particles according to the present invention, the thickness of the first coating portion is 1/5 or less of the average particle diameter of the insulating particles.

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

  In still another specific aspect of the conductive particles with insulating particles according to the present invention, the insulating particles are attached to the surface of the conductive portion through a chemical bond.

  In another specific aspect of the conductive particles with insulating particles according to the present invention, the insulating particles include inorganic particles.

  The coating is preferably formed of a compound having an alkyl group having 6 to 22 carbon atoms. The compound having an alkyl group having 6 to 22 carbon atoms is at least one selected from the group consisting of a phosphate ester or a salt thereof, a phosphite ester or a salt thereof, an alkoxysilane, an alkylthiol, and a dialkyl disulfide. Is preferred.

  In still another specific aspect of the conductive particles with insulating particles according to the present invention, the insulating particles cover the insulating particle main body and at least a part of the surface of the insulating particle main body, And a layer formed of a polymer compound.

  In another specific aspect of the conductive particles with insulating particles according to the present invention, the polymer compound is not attached to a portion other than the portion to which the insulating particles are attached on the surface of the conductive particles. .

  In another specific aspect of the conductive particle with insulating particles according to the present invention, the polymer compound is at least one reactive functional group selected from the group consisting of a (meth) acryloyl group, a glycidyl group, and a vinyl group. Has a group.

  In another specific aspect of the conductive particles with insulating particles according to the present invention, the insulating particles are not attached to the surface of the conductive particles by a hybridization method.

  In another specific aspect of the conductive particles with insulating particles according to the present invention, the conductive particles with insulating particles are treated with a 5% by weight aqueous citric acid solution to peel the coating film, thereby including a peeled coating film. After obtaining the treatment liquid, the filtrate obtained by filtering the treatment liquid contains 50 to 10,000 ppm of phosphorus element or silicon element.

  In another specific aspect of the conductive particles with insulating particles according to the present invention, the conductive particles with insulating particles are treated with a 5% by weight aqueous citric acid solution to peel the coating film, thereby including a peeled coating film. After obtaining the treatment liquid, the filtrate obtained by filtering the treatment liquid contains 50 to 10,000 ppm of phosphorus element.

  According to a wide aspect of the present invention, there is provided a conductive particle body with insulating particles having conductive particles having at least a conductive portion on the surface, and a plurality of insulating particles arranged on the surface of the conductive particles. Covering the surface and forming a film, and having a first film part covering the conductive particles and a second film part covering the surface of the insulating particles, And the manufacturing method of the electroconductive particle with an insulating particle which forms the said film so that the thickness in the said 1st film part is 1/2 or less of the average particle diameter of the said insulating particle is provided.

  The conductive material according to the present invention includes the above-described conductive particles with insulating particles and a binder resin. The conductive material is preferably a conductive paste.

  A connection structure according to the present invention includes a first connection target member, a second connection target member, and a connection portion that connects the first and second connection target members. The conductive particles with insulating particles described above are formed, or are formed with a conductive material containing the conductive particles with insulating particles and a binder resin.

  In the conductive particles with insulating particles according to the present invention, the surface of the conductive particle body with insulating particles is coated with a coating, and the coating is insulative with the first coating portion covering the conductive particles. A second coating portion covering the surface of the particles, and the thickness of the first coating portion is ½ or less of the average particle diameter of the insulating particles. This makes it difficult to unintentionally detach the insulating particles from the surface of the conductive particles and facilitates detachment of the insulating particles from the surface of the conductive particles during conductive connection.

  In the method for producing conductive particles with insulating particles according to the present invention, the surface of the conductive particle body with insulating particles covers the surface of the first coating portion covering the conductive particles and the surface of the insulating particles. And the second coating portion is formed so that the thickness of the first coating portion is ½ or less of the average particle diameter of the insulating particles. In addition, it is possible to obtain conductive particles with insulating particles that are difficult to unintentionally detach from the surface of the conductive particles and that easily detach from the surface of the conductive particles during conductive connection.

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 sectional view showing conductive particles with insulating particles according to the fourth embodiment of the present invention. FIG. 5 is a front cross-sectional view schematically showing a connection structure using the conductive particles with insulating particles shown in FIG. 1. FIG. 6 is a cross-sectional view showing a conventional conductive particle with insulating particles using a hybridization method.

  Hereinafter, the present invention will be clarified by describing specific embodiments and examples of the present invention with reference to the drawings.

(Conductive particle body with insulating particles)
FIG. 1 is a sectional view showing conductive particles with insulating particles according to the first embodiment of the present invention.

  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 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 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.

  FIG. 2 is a 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 23 covering the surface of the conductive particle body 22 with insulating particles. The coating 23 is attached to 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 15 arranged on the surface of the conductive particles 31. The insulating particles 15 are attached to the surface of the conductive particles 31.

  The coating 23 covers the surface of the conductive particles 31 and the surface of the insulating particles 15. The coating 23 has a first coating portion 23 a that covers the surface of the conductive particles 31, and a second coating portion 23 b that covers the surface of the insulating particles 15. The first coating portion 23a and the second coating portion 23b are continuous.

  The conductive particles 31 have base material particles 12 and a conductive layer 32 provided on the surface of the base material particles 12. The conductive layer 32 is a conductive part. The conductive particles 31 have a plurality of core substances 33 on the surface of the substrate particles 12. The conductive layer 32 covers the base particle 12 and the core substance 33. By covering the core substance 33 with the conductive layer 32, the conductive particles 31 have a plurality of protrusions 34 on the surface. The surface of the conductive layer 32 is raised by the core material 33, and a plurality of protrusions 34 are formed.

  In FIG. 3, the electroconductive particle with an insulating particle which concerns on the 3rd Embodiment of this invention is shown with sectional drawing.

  A conductive particle 41 with insulating particles shown in FIG. 3 includes a conductive particle body 42 with insulating particles and a coating 3 that covers the surface of the conductive particle body 42 with insulating particles.

  The conductive particle body 42 with insulating particles includes the conductive particles 11 and a plurality of insulating particles 45 arranged on the surface of the conductive particles 11. The insulating particles 45 are attached to the surface of the conductive particles 11. That is, except that the insulating particles are different, the conductive particles 41 with insulating particles are configured in the same manner as the conductive particles 1 with insulating particles, and the conductive particle body 42 with insulating particles is insulative. It is comprised similarly to the electroconductive particle main body 2 with a particle.

  The insulating particles 45 include an insulating particle main body 45a and a layer 45b that covers the surface of the insulating particle main body 45a and is formed of a polymer compound. Due to the presence of the layer 45b, the adhesion of the insulating particles 45 to the conductive particles 11 can be appropriately increased.

  The layer 45b covers the entire surface of the insulating particle main body 45a. Therefore, the layer 45b is disposed between the conductive particles 11 and the insulating particle main body 45a. The layer 45b may be present so as to cover at least a part of the surface of the insulating particle main body, and may not cover the entire surface of the insulating particle main body. The layer 45b is preferably disposed between the conductive particles and the insulating particle main body.

  FIG. 4 is a sectional view showing conductive particles with insulating particles according to the fourth embodiment of the present invention.

  The conductive particle 61 with insulating particles shown in FIG. 4 includes an insulating particle main body 62 and a coating 23 that covers the surface of the conductive particle main body 62 with insulating particles. The coating 23 is attached to the surface of the conductive particle body 62 with insulating particles.

  The conductive particle body 62 with insulating particles includes conductive particles 71 and a plurality of insulating particles 15 attached to the surface of the conductive particles 71.

  The conductive particles 71 have base material particles 12 and a conductive layer 76 provided on the surface of the base material particles 12. The conductive layer 76 is a conductive part. The conductive layer 76 includes a first conductive layer 76a provided on the surface of the base particle 12 and a second conductive layer 76b provided on the surface of the first conductive layer 76a. The conductive particles 71 have a plurality of core substances 33 on the surface of the first conductive layer 76a. The second conductive layer 76 b covers the first conductive layer 76 a and the core material 33. The substrate particles 12 and the core substance 33 are arranged with a space therebetween. A first conductive layer 76 a exists between the base particle 12 and the core substance 33. By covering the core substance 33 with the second conductive layer 76b, the conductive particles 71 have a plurality of protrusions 77 on the surface. The surfaces of the conductive layer 76 and the second conductive layer 76 b are raised by the core material 33, and a plurality of protrusions 77 are formed.

  In each of the conductive particles with insulating particles 1, 21, 41, 61, the thickness of the first coating portions 3a, 23a is 1/2 or less of the average particle diameter of the insulating particles 15, 35, 45.

  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. By being less than 1/2 of the particle diameter, it is difficult to unintentionally detach the insulating particles from the surface of the conductive particles before the conductive connection, and the insulating particles from the surface of the conductive particles during the conductive connection. Can be easily detached. Therefore, when the electrodes are connected using conductive particles with insulating particles, the conduction reliability can be improved. That is, it is possible to improve both the prevention of detachment of the insulating particles before the conductive connection and the detachability at the time of the conductive connection in the conductive particles with insulating particles. In general, a larger force that affects the detachment of insulating particles is applied during conductive connection than before conductive connection.

  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. The conductive particles with insulating particles according to the present invention can solve such problems.

  When the thickness of the first coating portion exceeds 1/2 of the average particle diameter of the insulating particles, the insulating particles are unlikely 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.

  From the viewpoint of effectively suppressing the separation of the insulating particles from the surface of the conductive particles during the conductive connection, the thickness of the first coating portion is preferably as thin as possible. The thickness of the first coating portion is preferably 1/3 or less, more preferably 1/5 or less of the average particle diameter of the insulating particles. In order to effectively fulfill the function of preventing the detachment of the insulating particles before the conductive connection, the thickness of the first coating portion is preferably 1/100 or more of the average particle diameter of the insulating particles. / 20 or more is more preferable.

  The “average particle diameter” of the insulating particles indicates a number average particle diameter. 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 second coating portion is preferably 1/2 or less, more preferably 1/5 or less of the average particle diameter of the insulating particles.

  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 5 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 μm 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.

  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. The conductive particles with insulating particles are preferably not covered with a coating and do not have exposed insulating particles.

  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 surface of the conductive part via 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 this film is formed with the compound which has a C6-C22 alkyl group. Thereby, it becomes difficult to produce rust in the conductive layer in the conductive particles with insulating particles.

  In addition, the conductive particles with insulating particles were treated with a 5% by weight citric acid aqueous solution to peel off the coating, thereby obtaining a treatment liquid containing the peeled coating and then filtering the treatment liquid. The filtrate preferably contains 50 to 10000 ppm of phosphorus element or silicon element. Thereby, it becomes difficult to produce rust in the conductive layer in the conductive particles with insulating particles. 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.

  Also, from the viewpoint of making rusting on the conductive layer even more difficult, a treatment liquid containing the peeled film is obtained by treating the conductive particles with insulating particles with a 5% by weight citric acid aqueous solution and peeling the film. Then, it is preferable that the filtrate obtained by filtering this process liquid contains 50-10000 ppm of phosphorus elements. From the viewpoint of making the conductive layer more difficult to rust, after treating the conductive particles with insulating particles with a 5 wt% aqueous citric acid solution and peeling the coating, a treatment liquid containing the peeled coating is obtained. The filtrate obtained by filtering the treatment liquid preferably contains 50 to 10,000 ppm of silicon element. The content of silicon element or phosphorus element in the filtrate is more preferably 100 ppm or more, more preferably 5000 ppm or less, still more preferably 1000 ppm or less, and particularly preferably 500 ppm or less. Further, from the viewpoint of further suppressing the separation of the insulating particles from the surface of the conductive particles before the conductive connection, the content of silicon element or phosphorus element in the filtrate is more preferably 100 ppm or more. It is.

  The contents of the phosphorus element and silicon element can be measured using an ICP emission analyzer. Examples of commercially available ICP emission analyzers include “ULTIMA2” manufactured by HORIBA, Ltd.

  In the case of conductive particles with insulating particles having a coating, the contents of the phosphorus element and the silicon element are usually determined by the coating. That is, the content of the phosphorus element and the silicon element indicates the ratio of the phosphorus element and the silicon element in the coating.

  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.

[Coating]
In order to make it difficult for rust to occur in the conductive portion, the coating is preferably formed of a compound having an alkyl group having 6 to 22 carbon atoms (hereinafter also referred to as compound A). When the carbon number of the alkyl group is less than 6, rust is likely to occur on the 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 insulating particles. 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.

[Conductive particle body with insulating particles]
The said electroconductive particle should just have an electroconductive part on the surface at least. The conductive part is, for example, a conductive layer. The conductive particles may be base particles and conductive particles having a conductive layer provided on the surface of the base particles, or may be metal particles that are conductive layers as a whole. Among these, from the viewpoint of reducing costs and increasing the flexibility of the conductive particles to increase the conduction reliability between the electrodes, the base particles and the conductive material provided on the surface of the base particles are used. Conductive particles having a layer are preferred.

  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 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 easily deformed during the above-described pressure bonding, and the contact area between the conductive particles and the electrode can be increased. For this reason, the conduction | electrical_connection reliability between electrodes can be improved.

  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, polypropylene, polyisobutylene, and polybutadiene; acrylic resins such as polymethyl methacrylate and polymethyl acrylate. Polyalkylene terephthalate, polycarbonate, polyamide, phenol formaldehyde resin, melamine formaldehyde resin, benzoguanamine formaldehyde resin, urea formaldehyde resin, phenol resin, melamine resin, benzoguanamine resin, urea resin, epoxy resin, unsaturated polyester resin, saturated polyester resin, polysulfone , Polyphenylene oxide, polyacetal, polyimide, polyamideimide, poly Ether ketone, polyether sulfone, 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 an ethylenically unsaturated group includes a non-crosslinkable monomer and a crosslinkable monomer. And so on.

  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 Child-containing (meth) acrylates; Nitrile-containing monomers such as (meth) acrylonitrile; Vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, and propyl vinyl ether; Vinyl acetates such as vinyl acetate, vinyl butyrate, vinyl laurate, and 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 di (meth) acrylate, 1,4-butanediol di (meth) acrylate; triallyl (iso) cyanurate, tria Rutorimeriteto, divinylbenzene, diallyl phthalate, diallyl acrylamide, diallyl ether, .gamma. (meth) acryloxy propyl trimethoxy silane, trimethoxy silyl styrene, include silane-containing monomers such as vinyltrimethoxysilane.

  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 polymerizing by swelling a monomer together with a radical polymerization initiator using non-crosslinked seed particles.

  In the case where the substrate particles are inorganic particles or organic-inorganic hybrid particles excluding metal particles, examples of the inorganic material for forming the substrate particles include silica and carbon black. Although it does not specifically limit as the particle | grains formed with the said silica, For example, after hydrolyzing the silicon compound which has two or more hydrolysable alkoxysil groups, and forming a crosslinked polymer particle, it calcinates as needed. 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, silicon, and these. And the like. 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 easily generated on the surface of the conductive part. By covering the surface of such a conductive part with a film, it is possible to effectively suppress the occurrence of rust on the 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 surface of the conductive portion by oxidation. In general, a hydroxyl group exists on the 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 can be further reduced. Moreover, when the outermost layer is a gold layer, the corrosion resistance can be further enhanced.

  The method for forming the conductive layer on the surface of the substrate particles is not particularly limited. As a method for forming the conductive layer, for example, a method by electroless plating, a method by electroplating, a method by physical vapor deposition, and a method of coating the surface of base particles with metal powder or a paste containing metal powder and a binder Etc. Especially, since formation of a conductive layer 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 size of the conductive particles is preferably in the range of 0.5 to 100 μm. The average particle diameter of the conductive particles is more preferably 1 μm or more, and more preferably 20 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. In addition, it is 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 conductive layer preferably has a thickness in the range of 0.005 to 1 μm. The thickness of the conductive layer is more preferably 0.01 μm or more, and more preferably 0.3 μm or less. When the thickness of the conductive layer is not less than the above lower limit and not more than the above upper limit, sufficient conductivity can be obtained, and the conductive particles do not become too hard, and the conductive particles are sufficiently bonded at the time of connection between the electrodes. Can be deformed.

  When the conductive layer is formed of a plurality of layers, the thickness of the outermost conductive layer is within the range of 0.001 to 0.5 μm, particularly when the outermost layer is a gold layer. It is preferable that A more preferable lower limit of the thickness of the outermost conductive layer is 0.01 μm, and a more preferable upper limit is 0.1 μm. When the thickness of the outermost conductive layer is not less than the above lower limit and not more than the above upper limit, the coating with the outermost conductive layer can be made uniform, corrosion resistance can be sufficiently enhanced, and the connection resistance between the electrodes can be increased. It can be made sufficiently low. Further, the thinner the gold layer when the outermost layer is a gold layer, the lower the cost.

  The thickness of the conductive layer can be measured, for example, by observing the cross section of the conductive particles or the conductive particles with insulating particles using a transmission electron microscope (TEM).

  The conductive particles preferably have protrusions on the surface of the conductive part, and the protrusions are preferably plural. An oxide film is often formed on the surface of the electrode connected by the conductive particles with insulating particles. When conductive particles with insulating particles having protrusions on the surface of the conductive part are used, the oxide film can be effectively eliminated by the protrusions by disposing the conductive particles between the electrodes and pressing them. For this reason, an electrode and an electroconductive part can be contacted still more reliably and the connection resistance between electrodes can be made 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 can be improved.

  As a method of forming protrusions on the surface of the conductive particles, a method of forming a conductive layer by electroless plating after attaching a core substance to the surface of the base particles, and by electroless plating on the surface of the base particles Examples of the method include forming a conductive layer, then attaching a core substance, and further forming a conductive layer by electroless plating.

  As a method of attaching the core substance to 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 accumulated on the base particle surface by, for example, van der Waals force. And a method of adding a core substance to a container containing base particles and causing the core substance to adhere to the surface of the base particles by mechanical action such as rotation of the container. 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 layer on the surface of the base particle, and may have a second conductive layer on the first conductive layer. In this case, a core substance may be attached to the surface of the first conductive layer. The core material is preferably covered with a second conductive layer. The thickness of the first conductive layer is preferably in the range of 0.05 to 0.5 μm. The conductive particles form a first conductive layer on the surface of the base particle, and then a core material is deposited on the surface of the first conductive layer, and then the first conductive layer and the core material are formed. It is preferably obtained by forming a second conductive layer on the surface.

  Examples of the material constituting the core material include conductive materials and non-conductive materials. 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 0.001 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 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 can be effectively lowered.

  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. In the case where protrusions are provided on the surface of the conductive particles, the insulating particles between the conductive portion and the electrode can be more easily removed.

  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 improving the detachability of the insulating particles during thermocompression bonding, the insulating particles preferably include inorganic particles, and are preferably silica particles. When the insulating particles do not have a layer formed of the above polymer compound on the surface, the insulating particles are preferably inorganic particles, and are preferably silica particles. When the 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, and is preferably silica particles. . Examples of the inorganic particles include shirasu particles, hydroxyapatite particles, magnesia particles, zirconium oxide particles, and silica particles. From the viewpoint of further improving the detachability of the insulating particles during thermocompression bonding, the insulating particles preferably include silica particles, and the inorganic particles are preferably 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. Among 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.

  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 surface of the conductive part of the conductive particles with insulating particles are attached, and the conduction reliability in the connection structure tends to be lowered. 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, preferably 100 parts by weight of the insulating particle body. Is 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.

  The following manufacturing conditions are mentioned as an example of the specific manufacturing conditions of the layer formed with the said high molecular compound.

  First, in 100 to 500 parts by weight of a solvent such as water, 1 to 3 parts by weight of an insulating particle body having a reactive functional group on the surface, and 0.1 to 20 parts by weight of a compound having a reactive double bond and a hydroxyl group (Preferably 0.1 to 1 part by weight), cross-linking agent 0.01 to 5 parts by weight (preferably 0.01 to 1 part by weight), dispersant 0.1 to 5 parts by weight (preferably 0.1 to 3 parts) Parts by weight) and 0.1-5 parts by weight (preferably 0.1-3 parts by weight) of a thermal polymerization initiator. Next, while stirring with a three-one motor, the temperature is raised to a temperature higher than the reaction temperature of the thermal polymerization initiator in an oil bath, polymerization is started, and the state is maintained for 5 hours or longer to react. Thereafter, unreacted compounds are removed using a centrifuge to obtain insulating particles in which the surface of the insulating particle main body is covered with the layer.

  Examples of the method for attaching insulating particles to the surfaces of the conductive particles and the conductive part include chemical methods and physical or mechanical methods. 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 surfaces of the conductive particles and the conductive part is a method other than the hybridization method. Is preferred. Among these, a method of attaching insulating particles to the surface of the conductive part 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.

  As shown in FIG. 6, in the conventional conductive particles 101 with insulating particles using the hybridization method, the portions 102 b other than the portions 102 a on the surface of the conductive particles 102 are attached to the portions 102 b. 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. 6 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 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 surface of the conductive part 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 first coating portion covering the conductive particles and the second coating portion covering the surface of the insulating particles, and the thickness of the first coating portion is the insulating property. The coating is formed so that the average particle diameter of the particles is ½ or less.

  In the method for producing conductive particles with insulating particles according to the present invention, the above insulating property is obtained by using a compound having 6 to 22 carbon atoms (compound A) 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 particle body.

  The method for forming a film on the surface of the conductive particle body with insulating particles using the compound A is not particularly limited, and a solution containing the compound A is attached to the surface of the conductive particle body with insulating particles. And the like.

  The solvent in the solution containing the compound A 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.

  The content of the compound A in the solution containing the compound A is appropriately adjusted so that a desired film is obtained. In 100% by weight of the solution containing the compound A, the content of the compound A is preferably in the range of 0.5 to 3% by weight.

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

(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.

  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. 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 method for dispersing the conductive particles with insulating particles in the binder resin is not particularly limited, and a conventionally known dispersion method can be used. Examples of a method for dispersing conductive particles with insulating particles in a binder resin include, for example, a method in which conductive particles with insulating particles are added to a binder resin and then kneaded and dispersed with a planetary mixer or the like. Conductive particles with particles are uniformly dispersed in water or an organic solvent using a homogenizer or the like, then added to the binder resin, kneaded and dispersed with a planetary mixer, etc., and the binder resin is water or organic Examples include a method of adding conductive particles with insulating particles after diluting with a solvent or the like, and kneading and dispersing with a planetary mixer or the like.

  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 in the range of 10 to 99.99% by weight. The content of the binder resin is more preferably 30% by weight or more, still more preferably 50% by weight or more, particularly preferably 70% by weight or more, and more preferably 99.9% by weight or more. 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 with insulating particles can be efficiently disposed between the electrodes, and the conduction reliability of the connection target member connected by the conductive material is further increased. Can be increased.

  In 100% by weight of the conductive material, the content of the conductive particles with insulating particles is preferably in the range of 0.01 to 20% by weight. The content of the conductive particles with the upper insulating particles is more preferably 0.1% by weight or more, more preferably 20% by weight or less, and still more preferably 15% by weight or less. When the content of the conductive particles with insulating particles is not less than the above lower limit and not more than the above upper limit, the conduction reliability between the electrodes can be 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 target member, a second connection target member, and a connection portion that electrically connects the first and second connection target members. The connection structure is formed of conductive particles with insulating particles or a conductive material (such as an anisotropic conductive material) including the conductive particles with insulating particles and a binder resin. preferable. 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. 5 is a cross-sectional view schematically showing a connection structure using the conductive particles 1 with insulating particles shown in FIG.

  The connection structure 51 shown in FIG. 5 includes a first connection target member 52, a second connection target member 53, and a connection portion 54 connecting the first and second connection target members 52 and 53. Prepare. The connection part 54 is formed of a conductive material including the conductive particles 1 with insulating particles and a binder resin. In FIG. 5, for convenience of illustration, the conductive particles 1 with insulating particles are schematically shown. Instead of the conductive particles 1 with insulating particles, the conductive particles 21, 41, 61 with insulating particles may be used.

  The first connection target member 52 has a plurality of electrodes 52b on the upper surface 52a (front surface). The second connection target member 53 has a plurality of electrodes 53b on the lower surface 53a (front surface). The electrode 52b and the electrode 53b are electrically connected by one or more conductive particles 1 with insulating particles. Therefore, the first and second connection target members 52 and 53 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 pressurized, the insulating particles 15 existing between the conductive particles 11 and the electrodes 52b and 53b can be eliminated. For example, during the heating and pressurization, the insulating particles 15 existing between the conductive particles 11 and the electrodes 52b and 53b are melted or deformed, so that 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 electrodes 52b and 53b, whereby the electrodes 52b and 53b can be electrically connected through the conductive particle 11.

  Specific examples of the connection target member include electronic components such as a semiconductor chip, a capacitor, and a diode, and circuit components such as a printed board, a flexible printed board, and a glass board. 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.

  The conductive particles with insulating particles according to the present invention are particularly suitable for COG having a glass substrate and a semiconductor chip as connection target members, or FOG having a glass substrate and a flexible printed circuit board (FPC) as connection target members. Is done. The conductive particles with insulating particles according to the present invention may be used for COG or FOG. In the connection structure according to the present invention, the first and second connection target members are preferably a glass substrate and a semiconductor chip, or a glass substrate and a flexible printed board. The first and second connection target members may be a glass substrate and a semiconductor chip, or may be a glass substrate and a flexible printed board.

It is preferable that bumps are provided on a semiconductor chip used in a COG having a glass substrate and a semiconductor chip as connection target members. The bump size is preferably an electrode area of 1000 μm ² or more and 10,000 μm ² or less. The electrode space in the semiconductor chip provided with the bump (electrode) is preferably 30 μm or less, more preferably 20 μm or less, and still more preferably 10 μm or less. For such COG applications, the conductive particles with insulating particles according to the present invention are preferably used. In the FPC used in the FOG using a glass substrate and a flexible printed circuit as a connection target member, the electrode space is preferably 30 μm or less, more preferably 20 μm or less.

  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 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
Conductive particles (average particle diameter: 3.01 μm, conductive layer thickness: 0.2 μm) having a metal layer having a nickel plating layer formed on the surface of divinylbenzene resin particles were prepared.

  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.

  In a mixed solution of 25 g of pure water and 25 g of ethanol, 10 parts by weight of the conductive particle body with insulating particles and 0.5 part by weight of monohexyl phosphate were added and stirred at 50 ° C. for 1 hour. Then, it is filtered and dried at 100 ° C. for 8 hours by a vacuum dryer, and conductive particles with insulating particles having a coating formed by the monohexyl phosphate are formed on the surface of the conductive particle body with insulating particles. 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 ( EDS) was used to observe the state of the film formed by monohexyl phosphate and to measure the thickness of the film. 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 thickness in the first coating portion was 1/5 or less of the average particle diameter of the insulating particles. 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 of 3.01 μm, conductive layer thickness of 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.

  In 200 mL of water, 1 part by weight of the insulating particle body, 0.22 part by weight of methacrylic acid, 0.05 part by weight of ethylene glycol dimethacrylate, and initiator (“V-50” manufactured by Wako Pure Chemical Industries, Ltd.) ) 0.5 part by weight was heated to 70 ° C. while sufficiently 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 thickness in the first coating portion was 1/5 or less of the average particle diameter of the insulating particles. 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)
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 (“2020SUS” manufactured by Mitsui Kinzoku Co., Ltd., 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 3.02 μm, and the thickness of the conductive layer was 0.2 μm. The conductive particles had protrusions on the surface.

  Except having used the obtained electroconductive particle, it carried out similarly to Example 1, and obtained the electroconductive particle with an insulating particle.

Example 4
Conductive particles with insulating particles were obtained in the same manner as in Example 1 except that monohexyl phosphate was changed to monooctyl phosphate.

(Example 5)
Conductive particles with insulating particles were obtained in the same manner as in Example 1 except that monohexyl phosphate was changed to monododecyl phosphate.

(Example 6)
Conductive particles with insulating particles were obtained in the same manner as in Example 1 except that the monohexyl phosphate was changed to monohexadecyl phosphate.

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

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

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

(Example 10)
Production of insulating particles:
The surface of silica particles (average particle size 200 nm) produced using the sol-gel method was coated with vinyltriethoxysilane, and insulating particles having vinyl groups as reactive functional groups on the surface were obtained as insulating particle bodies. . 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 mixture of water and ethanol in 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. Thereafter, the mixed solution was filtered, dried at 100 ° C. for 2 hours, and then sieved to obtain an insulating particle body.

  In 200 mL of water, 1 part by weight of the insulating particle main body, 2 parts by weight of methacrylic acid as a polymer compound, 1 part by weight of ethylene glycol dimethacrylate as a compound as a polymer compound, and an initiator (Wako Pure Chemical Industries "V-50") 0.5 parts by weight and polyoxyethylene lauryl ether (Kao "Emulgen 106") 1 part by weight as an emulsifier, and using an ultrasonic irradiation machine And sufficiently emulsified. Then, it heated up to 70 degreeC, fully stirring with a three-one motor, and hold | maintained at 70 degreeC for 6 hours, and the said monomer was polymerized.

  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 containing insulating particles. The average particle diameter of the insulating particles covered with the polymer compound in the state of the dispersion of the insulating particles was 324 nm.

Production of conductive particles with insulating particles:
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 11)
A dispersion containing insulating particles was obtained in the same manner as in Example 10 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 12)
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 10 except that the amount was changed to 1.0 part by weight of N, N-methylenebisacrylamide.

  The insulating particle body was obtained in the same manner as in Example 10 except that 10 parts by weight of silica particles and 0.1 part by weight of methacryloxypropyltriethoxysilane were used to obtain the insulating particle body. It was. 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 13)
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 14)
A dispersion containing insulating particles was prepared in the same manner as in Example 10 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 15)
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 rotations / minute. Conductive particles with particles were obtained.

(Example 16)
Insulation was carried out 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 1/3 (67 nm) of the particle diameter of the insulating particles. Conductive particles with conductive particles were obtained.

(Example 17)
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: 3.03 μm, conductive layer thickness: 0.21 μm) were used.

(Example 18)
By changing the amount of the material used when forming the coating, the conductive particles with insulating particles were treated with a 5% by weight aqueous citric acid solution and the coating was peeled off to obtain a treatment liquid containing the peeled coating. Thereafter, conductive particles with insulating particles were obtained in the same manner as in Example 1 except that the concentration of phosphorus element in the filtrate obtained by filtering the treatment liquid was 53 ppm.

(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: 3.01 μm, conductive layer thickness: 0.2 μm) having a metal layer having a nickel plating layer formed on the surface of divinylbenzene resin particles were prepared.

  In a mixed solution of 25 g of pure water and 25 g of ethanol, 10 parts by weight of the conductive particle body with insulating particles and 0.5 part by weight of monohexyl phosphate were added 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)
Insulating particles are provided in the same manner as in Example 1 except that the amount of the material used for forming the coating is changed and the thickness of the first coating is set to 2/3 of the particle size of the insulating particles. Conductive particles were obtained.

(Evaluation)
(1) Evaluation of content of phosphorus element or silicon element in conductive particles with insulating particles 1 part by weight of conductive particles with insulating particles of Examples and Comparative Examples was added to 5 wt% aqueous citric acid solution (5 wt% A solution obtained by dissolving citric acid in 95% by weight of water) was added to 100 parts by weight, stirred at 40 ° C. for 30 minutes to obtain a treatment liquid, and then the treatment liquid was filtered through a filter paper to obtain a filtrate. In the conductive particles with insulating particles of Examples 1 to 18 and Comparative Examples 1 to 3, the coating adhered to the surface of the conductive particle body with insulating particles was peeled off after the treatment with the citric acid aqueous solution. .

  The content of phosphorus element or silicon element in the obtained filtrate was measured using an ICP emission analyzer (“ULTIMA2” manufactured by Horiba, Ltd.).

(2) Preparation of connection structure Conductive particles with insulating particles of Examples and Comparative Examples were added to Mitsui Chemicals' “Struct Bond XN-5A”) so that the content would be 10% by weight, and dispersed. An anisotropic conductive paste was obtained.

  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 1 MPa is applied to form the anisotropic conductive paste layer. Completely cured at 185 ° C. to obtain a connection structure.

(3) Conductivity evaluation (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. “○” indicates that the average value of the connection resistance is 2.0Ω or less and the polymer compound is not attached to any part other than the part where the insulating particles are attached on the surface of the conductive particles. When the average value of 2Ω is 2Ω or less, “△” indicates that there is a portion where the 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 results are shown in Table 1 below, assuming that the average value exceeds 2Ω as “x”.

(4) Insulation evaluation (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. When the resistance exceeds 500 MΩ, it is determined that there is no leakage and the result is “◯”, and when the resistance is 500 MΩ or less, it is determined that there is leakage and the result is “X”.

(5) Rust prevention evaluation The connection structure produced by the above-mentioned insulation evaluation 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. When the average connection resistance (after leaving) is less than 150% compared to the average value of the connection resistance (before leaving) at the time of the above continuity evaluation, “○” indicates that the average value of the connection resistance (after leaving) is The results are shown in Table 1 below, where “x” indicates a case where the temperature rose by 150% or more.

(6) Insulation particle detachment preventing property before conductive connection Further, in the anisotropic conductive paste obtained by the insulation evaluation, it was observed whether 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)

(7) Detachability of insulating particles during conductive connection In the connection structure obtained by the above continuity evaluation, the electrode and the conductive particles are not detached from the surface of the conductive particles or after the desorption. It was evaluated whether or not there were insulating particles sandwiched between the two.

[Judgment criteria for detachability of insulating particles]
○: Insulating particles sandwiched between electrodes and conductive particles do not exist ×: Insulating particles sandwiched between electrodes and conductive particles exist

  The results are shown in Table 1 below. In Table 1 below, the thickness of the coating film indicates the thickness when the particle diameter of the insulating particles is 1, based on the particle diameter of the insulating particles. In Examples 1 to 15, 17, and 18, the thickness of the coating was 1/100 or more of the particle diameter of the insulating particles.

  As shown in Table 1 above, in the rust prevention evaluation using the conductive particles with insulating particles of Comparative Example 1, the resistance value increased by 150% or more. This is because rust has occurred on the surface of the conductive layer.

  Further, in the conductive particles with insulating particles of Examples 1 to 14 and 16 to 18, the polymer compound is not attached to the portion other than the portion to which the insulating particles are attached on the surface of the conductive particles. It was confirmed. In Example 15, since the physical / mechanical hybridization method is used, the portion where the polymer compound is attached to the portion other than the portion where the insulating particles are attached on the surface of the conductive particles. was there. Thus, if the polymer compound is attached to a portion other than the portion to which the insulating particles are attached on the surface of the conductive particles, the conduction reliability may be lowered depending on the case.

  In addition, in the anisotropic conductive paste using the conductive particles with insulating particles of Examples 1 to 18, the conductive paste is more conductive than the anisotropic conductive paste using the conductive particles with insulating particles of Comparative Example 1. The ratio of insulating particles detached from the surface of the conductive particles was extremely small. In particular, the anisotropic conductive paste using the conductive particles with insulating particles of Example 1 is more conductive than the anisotropic conductive paste using the conductive particles with insulating particles of Comparative Examples 1 and 2. The ratio of insulating particles detached from the surface of the conductive particles was extremely small. This is considered to be because the conductive particles with insulating particles of Examples 1 to 18 have the above-described coating formed thereon, so that the detachment of the insulating particles is suppressed. Moreover, the anisotropic conductive paste using the conductive particles with insulating particles of Examples 1 to 15, 17, and 18 is compared with the anisotropic conductive paste using the conductive particles with insulating particles of Example 16. Thus, the ratio of insulating particles detached from the surface of the conductive particles was small. The evaluation results of the anti-detachment property before conductive connection between Example 16 and Example 18 are both “Δ”, but the ratio of the insulating particles detached from the surface of the conductive particles is 18 was less than Example 16.

  Furthermore, the anisotropic conductive paste using the conductive particles with insulating particles of Example 2 is more conductive than the anisotropic conductive paste using the conductive particles with insulating particles of Example 1. The ratio of the insulating particles detached from the surface of the film was small. This is probably because in the insulating particles of Example 2, the surface of the insulating particles was covered with a flexible layer formed of a polymer compound, so that the detachment of the insulating particles was suppressed.

  Further, in Comparative Example 3, there were insulating particles sandwiched between the electrode and the conductive particles, but the level did not affect the conductivity, and the evaluation result of the conductivity evaluation was “◯”. It was.

DESCRIPTION OF SYMBOLS 1 ... Conductive particle with insulating particle 2 ... Conductive particle main body with insulating particle 3 ... Coating 3a ... 1st coating part 3b ... 2nd coating part 11 ... Conductive particle 12 ... Base particle 13 ... Conductive layer (Conductive part)
DESCRIPTION OF SYMBOLS 15 ... Insulating particle 21 ... Conductive particle with insulating particle 22 ... Conductive particle main body with insulating particle 23 ... Coating 23a ... 1st coating part 23b ... 2nd coating part 31 ... Conductive particle 32 ... Conductive layer (Conductive part)
33 ... Core material 34 ... Projection 35 ... Insulating particle 41 ... Conductive particle with insulating particle 42 ... Conductive particle body with insulating particle 45 ... Insulating particle 45a ... Insulating particle body 45b ... Layer 51 ... Connection structure 52 ... 1st connection object member 52a ... Upper surface 52b ... Electrode 53 ... 2nd connection object member 53a ... Lower surface 53b ... Electrode 54 ... Connection part 61 ... Conductive particle with insulating particle 62 ... Conductive particle with insulating particle Main body 71 ... Conductive particles 76 ... Conductive layer 76a ... First conductive layer 76b ... Second conductive layer 77 ... Projection

Claims (15)

Conductive particles having at least a conductive portion on the surface, and conductive particle bodies with insulating particles having a plurality of insulating particles arranged on the surface of the conductive particles;
A coating covering the surface of the conductive particle body with insulating particles,
The coating has a first coating portion covering the conductive particles and a second coating portion covering the surfaces of the insulating particles,
The thickness of the first coating portion is ½ or less of the average particle diameter of the insulating particles and 80 nm or less,
Wherein the surface of the conductive portion via a chemical bond, wherein that have insulating particles adhere, insulating particles with the conductive particles. Conductive particles having at least a conductive portion on the surface, and conductive particle bodies with insulating particles having a plurality of insulating particles arranged on the surface of the conductive particles;
A coating covering the surface of the conductive particle body with insulating particles,
The coating has a first coating portion covering the conductive particles and a second coating portion covering the surfaces of the insulating particles,
A thickness of the first coating portion is ½ or less of an average particle diameter of the insulating particles;
Filtration obtained by treating the conductive particles with insulating particles with a 5% by weight citric acid aqueous solution to peel off the film to obtain a treatment liquid containing the peeled film, and then filtering the treatment liquid. Conductive particles with insulating particles, wherein the liquid contains 50 to 10,000 ppm of phosphorus element or silicon element. Filtration obtained by treating the conductive particles with insulating particles with a 5% by weight citric acid aqueous solution to peel off the film to obtain a treatment liquid containing the peeled film, and then filtering the treatment liquid. The conductive particles with insulating particles according to claim 2, wherein the liquid contains 50 to 10,000 ppm of phosphorus element. Conductive particles having at least a conductive portion on the surface, and conductive particle bodies with insulating particles having a plurality of insulating particles arranged on the surface of the conductive particles;
A coating covering the surface of the conductive particle body with insulating particles,
The coating has a first coating portion covering the conductive particles and a second coating portion covering the surfaces of the insulating particles,
A thickness of the first coating portion is ½ or less of an average particle diameter of the insulating particles;
Compound having an alkyl group having 6 to 22 carbon atoms, wherein the coating is at least one selected from the group consisting of phosphate ester or salt thereof, phosphite ester or salt thereof, alkoxysilane, alkylthiol and dialkyl disulfide Conductive particles with insulating particles formed by The conductive particles with insulating particles according to any one of claims 1 to 4 , wherein a thickness of the first coating portion is 1/5 or less of an average particle diameter of the insulating particles. The conductive particles with insulating particles according to any one of claims 1 to 5 , wherein 90% or more of the total number of the plurality of insulating particles is in contact with the conductive particles. A plurality of said insulating particles, not exposed by being covered by the coating, the insulating particles with conductive particles according to any one of claims 1-6. The insulating particles comprise inorganic particles, insulating particles with the conductive particles according to any one of claims 1-7.   The insulating particle has an insulating particle body and a layer that covers at least a part of the surface of the insulating particle body and is formed of a polymer compound. The electroconductive particle with an insulating particle of any one of Claims 1.   The conductive particles with insulating particles according to claim 9, wherein the polymer compound is not attached to a portion other than the portion to which the insulating particles are attached on the surface of the conductive particles.   The conductive particle with insulating particles according to claim 9 or 10, wherein the polymer compound has at least one reactive functional group selected from the group consisting of a (meth) acryloyl group, a glycidyl group, and a vinyl group. .   The conductive particles with insulating particles according to claim 1, wherein the insulating particles are not attached to the surface of the conductive particles by a hybridization method. And insulating particles with conductive particle according to any one of claims 1 to 12 and a binder resin, conductive material. The conductive material according to claim 13 , which is a conductive paste. A first connection target member, a second connection target member, and a connection portion connecting the first and second connection target members;
The connection part is formed of the conductive particles with insulating particles according to any one of claims 1 to 12 , or is formed of a conductive material including the conductive particles with insulating particles and a binder resin. A connection structure.

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