JP2019212467A - Conductive material, connection structure, and method for manufacturing connection structure - Google Patents

Abstract

To provide a conductive material which, when electrically connecting between electrodes, can effectively increase conduction reliability and, further, can effectively increase insulation reliability.SOLUTION: The conductive material comprises a thermosetting component, a plurality of conductive particles, and a surfactant which removes an oxide layer of the conductive particles, wherein the thermosetting component contains a thermosetting compound, and the thermosetting component does not contain or contains a thermosetting agent. When the thermosetting component does not contain the thermosetting agent, an absolute value of the difference between the SP value of the thermosetting compound and the SP value of the surfactant is 2 or less, and when the thermosetting component contains the thermosetting agent, an absolute value of the difference between an SP value of the thermosetting compound and an SP value of the surfactant is 2 or less.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a conductive material including a thermosetting component and conductive particles. The present invention also relates to a connection structure using the conductive material and a method for manufacturing the connection structure.

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

  The anisotropic conductive material is used to obtain various connection structures. Examples of the connection using the anisotropic conductive material include a connection between a flexible printed circuit board and a glass substrate (FOG (Film on Glass)), a connection between a semiconductor chip and a flexible printed circuit board (COF (Chip on Film)), and a semiconductor. Examples include connection between a chip and a glass substrate (COG (Chip on Glass)), connection between a flexible printed circuit board and a glass epoxy substrate (FOB (Film on Board)), and the like.

  For example, when electrically connecting the electrode of the flexible printed circuit board and the electrode of the glass epoxy substrate by the anisotropic conductive material, an anisotropic conductive material containing conductive particles is disposed on the glass epoxy substrate. To do. Next, a flexible printed circuit board is laminated, and heated and pressurized. As a result, the anisotropic conductive material is cured, and the electrodes are electrically connected via the conductive particles to obtain a connection structure.

  Patent Document 1 below discloses a water-soluble flux for solder paste containing an acrylic resin having a carboxyl group, a thixotropic agent, a solvent, and an activator. The acrylic resin includes a (meth) acrylic acid ester monomer having an SP value of 9.4 to 12, a (meth) acrylic acid monomer, the (meth) acrylic acid ester monomer, and the (meth And other monomers having a vinyl group copolymerizable with an acrylic acid monomer. The acid value of the acrylic resin is 50 mgKOH / g to 250 mgKOH / g. The acrylic resin has a mass average molecular weight of 1,000 to 20,000. Patent Document 1 below describes a solder paste containing the above-described water-soluble flux for solder paste and solder powder.

  Patent Document 2 below discloses a solder composition containing (A) a rosin resin, (B) an activator, (C) a solvent and (D) a flux containing an antifoaming agent, and (E) a solder powder. Is disclosed. The component (D) has a solubility parameter (SP value) of 9.5 or less and a weight average molecular weight of 100,000 or more.

Japanese Patent Laid-Open No. 2006-150344 JP-A-2015-131336

  When conducting a conductive connection using a conductive material containing conductive particles, the plurality of upper electrodes and the plurality of lower electrodes are electrically connected to each other to conduct the conductive connection. The conductive particles are desirably disposed between the upper and lower electrodes, and are preferably not disposed between the adjacent lateral electrodes. It is desirable that the adjacent lateral electrodes are not electrically connected.

  Generally, a conductive material containing conductive particles is used after being disposed at a specific position on a substrate and then heated by reflow or the like. When the conductive material is heated to a temperature equal to or higher than the melting point of the conductive particles, the conductive particles are melted and a metal such as solder is aggregated between the electrodes, so that the upper and lower electrodes are electrically connected.

  In a conventional conductive material, when heated by reflow or the like, the viscosity of the thermosetting compound or the like contained in the conductive material decreases before reaching the melting point of the conductive particles, the conductive material flows, and the shape of the conductive material becomes May change. When the conductive material flows, the conductive particles contained in the conductive material may move and move away from the place where the conductive material should be originally disposed (for example, in the vicinity of the electrode). Due to the flow of the conductive material, the conductive particles may not be efficiently arranged between the upper and lower electrodes to be connected. As a result, the amount of conductive particles disposed between the upper and lower electrodes to be connected is reduced, the conduction reliability between the upper and lower electrodes to be connected is lowered, and the insulation between adjacent lateral electrodes is reduced. Reliability may be reduced. In the conventional conductive material, it is difficult to suppress the movement of the conductive particles due to the flow of the conductive material.

  An object of the present invention is to provide a conductive material capable of effectively increasing conduction reliability and further improving insulation reliability when the electrodes are electrically connected. . Another object of the present invention is to provide a connection structure using the conductive material and a method for manufacturing the connection structure.

  According to a wide aspect of the present invention, the thermosetting component includes a thermosetting component, a plurality of conductive particles, and an activator that removes an oxide film of the conductive particles, and the thermosetting component contains a thermosetting compound. Including, when the thermosetting component does not include or includes a thermosetting agent, and the thermosetting component does not include the thermosetting agent, the SP value of the thermosetting compound and the activator When the absolute value of the difference from the SP value is 2 or less and the thermosetting component contains the thermosetting agent, the SP value of the mixture of the thermosetting compound and the thermosetting agent, A conductive material is provided in which the absolute value of the difference from the SP value of the activator is 2 or less.

  In a specific aspect of the conductive material according to the present invention, the conductive particles include tin, bismuth, copper, gold, silver, or indium.

  In a specific aspect of the conductive material according to the present invention, the activator is an acidic phosphate ester.

  On the specific situation with the electrically-conductive material which concerns on this invention, the acid value of the said activator is 280 mgKOH / g or more and 580 mgKOH / g or less.

  On the specific situation with the electrically-conductive material which concerns on this invention, SP value of the said active agent is 20-28.

  On the specific situation with the electrically-conductive material which concerns on this invention, content of the said activator with respect to 100 weight part of said thermosetting compounds is 1 weight part or more and 10 weight part or less.

  According to a wide aspect of the present invention, a first connection target member having a first electrode on the surface, a second connection target member having a second electrode on the surface, the first connection target member, A connecting portion connecting the second connection target member, wherein the material of the connecting portion is the conductive material described above, and the first electrode and the second electrode are the connecting portion. To provide a connection structure that is electrically connected.

  According to a wide aspect of the present invention, using the conductive material described above, the step of disposing the conductive material on the surface of the first connection target member having the first electrode on the surface; On the surface opposite to the first connection target member side, the second connection target member having the second electrode on the surface is arranged so that the first electrode and the second electrode face each other. Forming a connection portion connecting the first connection target member and the second connection target member with the conductive material by heating the conductive material to a temperature equal to or higher than the melting point of the conductive particles; And the manufacturing method of a connection structure provided with the process of electrically connecting a said 1st electrode and a said 2nd electrode by the said connection part is provided.

  The conductive material according to the present invention includes a thermosetting component, a plurality of conductive particles, and an activator that removes an oxide film of the conductive particles. In the conductive material according to the present invention, the thermosetting component contains a thermosetting compound. In the conductive material according to the present invention, the thermosetting component does not contain or contains a thermosetting agent. In the conductive material according to the present invention, when the thermosetting component does not contain the thermosetting agent, the absolute value of the difference between the SP value of the thermosetting compound and the SP value of the activator is 2 It is as follows. In the conductive material according to the present invention, when the thermosetting component contains the thermosetting agent, the SP value of the mixture of the thermosetting compound and the thermosetting agent and the SP value of the activator The absolute value of the difference is 2 or less. Since the conductive material according to the present invention has the above-described configuration, when the electrodes are electrically connected, the conduction reliability can be effectively increased, and the insulation reliability can be effectively increased. Can be increased.

FIG. 1 is a cross-sectional view schematically showing a connection structure obtained using a conductive material according to an embodiment of the present invention. 2A to 2C are cross-sectional views for explaining each step of an example of a method for manufacturing a connection structure using a conductive material according to an embodiment of the present invention. FIG. 3 is a cross-sectional view showing a modification of the connection structure. FIG. 4 is a cross-sectional view showing conductive particles that can be used in the conductive material according to the first embodiment of the present invention. FIG. 5 is a cross-sectional view showing conductive particles that can be used in the conductive material according to the second embodiment of the present invention. FIG. 6 is a cross-sectional view showing conductive particles that can be used in the conductive material according to the third embodiment of the present invention.

  Details of the present invention will be described below.

(Conductive material)
The conductive material according to the present invention includes a thermosetting component, a plurality of conductive particles, and an activator that removes an oxide film of the conductive particles. In the conductive material according to the present invention, the thermosetting component contains a thermosetting compound. In the conductive material according to the present invention, the thermosetting component does not contain or contains a thermosetting agent. In the conductive material according to the present invention, when the thermosetting component does not contain the thermosetting agent, the absolute value of the difference between the SP value of the thermosetting compound and the SP value of the activator is 2 It is as follows. In the conductive material according to the present invention, when the thermosetting component contains the thermosetting agent, the SP value of the mixture of the thermosetting compound and the thermosetting agent and the SP value of the activator The absolute value of the difference is 2 or less. Hereinafter, when the said thermosetting component contains the said thermosetting agent, the mixture of the said thermosetting compound and the said thermosetting agent may be described as a mixture (M).

  Since the conductive material according to the present invention has the above-described configuration, when the electrodes are electrically connected, the conduction reliability can be effectively increased, and the insulation reliability can be effectively increased. Can be increased.

  A conductive material containing conductive particles is used after being placed at a specific position on a substrate and then heated by reflow or the like. When the conductive material is heated to a temperature equal to or higher than the melting point of the conductive particles, the conductive particles are melted and a metal such as solder is aggregated between the electrodes, so that the upper and lower electrodes are electrically connected.

  In a conventional conductive material, when heated by reflow or the like, the viscosity of the thermosetting compound or the like contained in the conductive material decreases before reaching the melting point of the conductive particles, the conductive material flows, and the shape of the conductive material becomes May change. When the conductive material flows, the conductive particles contained in the conductive material may move and move away from the place where the conductive material should be originally disposed (for example, in the vicinity of the electrode). Due to the flow of the conductive material, the conductive particles may not be efficiently arranged between the upper and lower electrodes to be connected.

  The inventors pay attention to the compatibility between the activator and the thermosetting compound, or the compatibility between the activator and the mixture (M), and the specific activator, the specific thermosetting compound, and the specific thermosetting. It has been found that by using an agent, the ability of the activator to remove an oxide film can be improved, the conductive particles can be bonded by metal diffusion, and the shape of the conductive material can be maintained. In the present invention, the ability of the active agent to remove the oxide film can be exhibited at a relatively low temperature at which the flow of the conductive material occurs, and the conductive particles can be bonded together by metal diffusion. For this reason, it becomes difficult for the conductive material to flow, and the conductive particles do not move and can stay at the place where they are originally arranged. In the present invention, by electrically connecting conductive particles and maintaining the shape of the conductive material, when the electrodes are electrically connected, the conduction reliability between the upper and lower electrodes to be connected is effectively increased. be able to.

  Further, by bonding the conductive particles and maintaining the shape of the conductive material, the conductive particles remaining between adjacent lateral electrodes can be reduced when the electrodes are electrically connected. As a result, it is possible to effectively increase the insulation reliability between adjacent lateral electrodes that should not be connected.

  In the present invention, since the above-described configuration is provided, when the electrodes are electrically connected, the conductive particles are likely to gather between the upper and lower electrodes, and the conductive particles are placed on the electrodes (lines). Can be arranged. In addition, it is difficult for a part of the conductive particles to be disposed between the lateral electrodes that should not be connected, and the amount of the conductive particles disposed between the lateral electrodes that should not be connected may be considerably reduced. it can. As a result, in the present invention, the remaining amount of conductive particles can be reduced between the lateral electrodes that should not be connected.

  In the present invention, in order to obtain the effects as described above, it greatly contributes that the conductive material contains a specific activator, a specific thermosetting compound, and a specific thermosetting agent.

  Furthermore, in the present invention, it is possible to prevent positional deviation between the electrodes. In the present invention, when the second connection target member is superimposed on the first connection target member having the conductive material disposed on the upper surface, the electrode of the first connection target member and the electrode of the second connection target member Even in a state of misalignment, the electrodes can be connected by correcting the misalignment (self-alignment effect).

  From the viewpoint of more effectively increasing the conduction reliability and the insulation reliability when the electrodes are electrically connected, the conductive material is preferably liquid at 25 ° C., and is preferably a conductive paste. preferable. The conductive material is preferably a conductive paste at 25 ° C.

  From the viewpoint of more effectively increasing the conduction reliability and the insulation reliability when the electrodes are electrically connected, the viscosity (η25) at 25 ° C. of the conductive material is preferably 30 Pa · s or more, More preferably, it is 50 Pa · s or more, preferably 400 Pa · s or less, more preferably 300 Pa · s or less. The said viscosity ((eta) 25) can be suitably adjusted with the kind and compounding quantity of a compounding component.

  The viscosity (η25) can be measured, for example, using an E-type viscometer (“TVE22L” manufactured by Toki Sangyo Co., Ltd.) and the like at 25 ° C. and 5 rpm.

  The conductive material can be used as a conductive paste and a conductive film. The conductive paste is preferably an anisotropic conductive paste, and the conductive film is preferably an anisotropic conductive film. In the case where the electrodes are electrically connected, the conductive material is preferably a conductive paste from the viewpoint of more effectively increasing the conduction reliability and the insulation reliability. The conductive material is preferably used for electrical connection of electrodes. The conductive material is preferably a circuit connection material.

  Hereinafter, each component contained in the conductive material will be described.

(Conductive particles)
The conductive material includes a plurality of conductive particles. The conductive particles are not particularly limited. The conductive particles may be solder particles or metal particles. The said electroconductive particle may have a base material particle and the electroconductive part arrange | positioned on the surface of this base material particle. The conductive particles preferably contain solder in the conductive part. The conductive particles may contain only solder particles, may contain solder particles and conductive particles other than solder particles, or may contain only conductive particles other than solder particles.

  The conductive particles contain tin, bismuth, copper, gold, silver, or indium from the viewpoint of further improving the conduction reliability and the insulation reliability more effectively when the electrodes are electrically connected. Is preferable, and it is more preferable that tin, bismuth, copper, silver or gold is included.

  The content of the conductive particles in 100% by weight of the conductive material is preferably 40% by weight or more, more preferably 45% by weight or more, further preferably 55% by weight or more, and particularly preferably 60% by weight or more. Is 90% by weight or less, more preferably 85% by weight or less, and still more preferably 80% by weight or less. When the content of the conductive particles is not less than the above lower limit and not more than the above upper limit, it is possible to more efficiently arrange the solder on the electrodes, and it is easy to arrange much solder between the electrodes, The conduction reliability and the insulation reliability can be further effectively improved.

  The content of the solder particles in 100% by weight of the conductive particles is preferably 50% by weight or more, more preferably 60% by weight or more, still more preferably 70% by weight or more, and even more preferably 80% by weight or more. Preferably it is 90 weight% or more, Most preferably, it is 100 weight%. When the content of the solder particles is not less than the above lower limit and not more than the above upper limit, it is possible to more efficiently arrange the solder on the electrodes, and it is easy to dispose a lot of solder between the electrodes. Reliability and insulation reliability can be further improved effectively.

  In the present specification, the term “100% by weight of conductive particles” means the total weight of the conductive particles contained in the conductive material.

  Next, specific examples of conductive particles will be described with reference to the drawings.

  FIG. 4 is a cross-sectional view showing conductive particles that can be used in the conductive material according to the first embodiment of the present invention.

  The conductive particles 21 shown in FIG. 4 are solder particles. The conductive particles 21 are entirely formed of solder. The conductive particles 21 do not have base particles in the core, and are not core-shell particles. As for the electroconductive particle 21, both the center part and the outer surface part of an electroconductive part are formed with the solder.

  FIG. 5 is a cross-sectional view showing conductive particles that can be used in the conductive material according to the second embodiment of the present invention.

  The conductive particle 31 shown in FIG. 5 includes a base particle 32 and a conductive part 33 disposed on the surface of the base particle 32. The conductive portion 33 covers the surface of the base particle 32. The conductive particles 31 are coated particles in which the surface of the base particle 32 is covered with the conductive portion 33.

  The conductive portion 33 includes a second conductive portion 33A and a first conductive portion 33B. The conductive particles 31 include a second conductive portion 33A between the base particle 32 and the first conductive portion 33B. Accordingly, the conductive particles 31 include the base particles 32, the second conductive portion 33A disposed on the surface of the base particles 32, and the first conductive layer 33A disposed on the outer surface of the second conductive portion 33A. And a conductive portion 33B.

  FIG. 6 is a cross-sectional view showing conductive particles that can be used in the conductive material according to the third embodiment of the present invention.

  As described above, the conductive portion 33 in the conductive particle 31 has a two-layer structure. The conductive particle 41 illustrated in FIG. 6 includes a conductive portion 42 as a single-layer conductive portion. The conductive particles 41 include base particles 32 and conductive portions 42 disposed on the surface of the base particles 32.

  Hereinafter, other details of the conductive particles will be described.

Solder particles:
As for the said solder particle, both a center part and an outer surface are formed with the solder. The solder particles are particles in which both the central portion and the outer surface are solder. In place of the solder particles, when conductive particles including base particles formed from a material other than solder and solder portions arranged on the surface of the base particles are used, the conductive particles are conductive on the electrodes. Particles are difficult to collect. Moreover, in the said electroconductive particle, since the solder joint property of electroconductive particles is low, there exists a tendency for the electroconductive particle which moved on the electrode to move outside an electrode, and the effect of suppressing the position shift between electrodes is also effective. Tend to be lower.

  The solder is preferably a metal (low melting point metal) having a melting point of 450 ° C. or lower. The solder particles are preferably metal particles (low melting point metal particles) having a melting point of 450 ° C. or lower. The low melting point metal particles are particles containing a low melting point metal. The low melting point metal is a metal having a melting point of 450 ° C. or lower. The melting point of the low melting point metal is preferably 300 ° C. or lower, more preferably 160 ° C. or lower. The solder particles are preferably low melting point solder having a melting point of less than 150 ° C.

  The melting point of the solder particles can be determined by differential scanning calorimetry (DSC). Examples of the differential scanning calorimetry (DSC) apparatus include “EXSTAR DSC7020” manufactured by SII.

  The solder particles preferably contain tin. In 100% by weight of the metal contained in the solder particles, the content of tin is preferably 30% by weight or more, more preferably 40% by weight or more, still more preferably 70% by weight or more, and particularly preferably 90% by weight or more. . When the tin content in the solder particles is equal to or higher than the lower limit, the conduction reliability and the connection reliability between the solder portion and the electrode are further enhanced.

  The tin content is determined using a high frequency inductively coupled plasma optical emission spectrometer (“ICP-AES” manufactured by Horiba, Ltd.) or a fluorescent X-ray analyzer (“EDX-800HS” manufactured by Shimadzu). Can be measured.

  By using the solder particles, the solder particles are melted and joined to the electrodes, and the solder portion conducts between the electrodes. For example, since the solder portion and the electrode are not in point contact but in surface contact, the connection resistance is lowered. Moreover, as a result of the use of the solder particles, the bonding strength between the solder part and the electrode is increased. As a result, peeling between the solder part and the electrode is less likely to occur, and the conduction reliability and the connection reliability are further improved.

  The low melting point metal constituting the solder particles is not particularly limited. The low melting point metal is preferably tin or an alloy containing tin. Examples of the alloy include a tin-silver alloy, a tin-copper alloy, a tin-silver-copper alloy, a tin-bismuth alloy, a tin-zinc alloy, and a tin-indium alloy. The low melting point metal is preferably tin, a tin-silver alloy, a tin-silver-copper alloy, a tin-bismuth alloy, or a tin-indium alloy because of its excellent wettability with respect to the electrode. The low melting point metal is more preferably a tin-bismuth alloy or a tin-indium alloy.

  The solder particles are preferably a filler material having a liquidus line of 450 ° C. or lower based on JIS Z3001: welding terms. Examples of the composition of the solder particles include metal compositions containing zinc, gold, silver, lead, copper, tin, bismuth, indium and the like. A tin-indium system (117 ° C eutectic) or a tin-bismuth system (139 ° C eutectic) that has a low melting point and is free of lead is preferable. That is, the solder particles preferably do not contain lead, and preferably contain tin and indium, or contain tin and bismuth.

  In order to further increase the bonding strength between the solder part and the electrode, the solder particles include nickel, copper, antimony, aluminum, zinc, iron, gold, titanium, phosphorus, germanium, tellurium, cobalt, bismuth, manganese, chromium, Metals such as molybdenum and palladium may be included. Moreover, from the viewpoint of further increasing the bonding strength between the solder portion and the electrode, the solder particles preferably contain nickel, copper, antimony, aluminum, or zinc. From the viewpoint of further increasing the bonding strength between the solder part and the electrode, the content of these metals for increasing the bonding strength is 100 wt% of the metal contained in the solder particles, preferably 0.0001 wt% or more, Preferably it is 1 weight% or less.

  The particle diameter of the solder particles is preferably 1 μm or more, more preferably 2 μm or more, preferably 30 μm or less, more preferably 20 μm or less, and even more preferably 10 μm or less. When the particle diameter of the solder particles is not less than the above lower limit and not more than the above upper limit, the solder particles can be more efficiently disposed on the electrode than the solder. The particle diameter of the solder particles is particularly preferably 3 μm or more and 10 μm or less.

  The particle diameter of the solder particles is preferably an average particle diameter, and more preferably a number average particle diameter. The particle size of the solder particles is, for example, observing 50 arbitrary solder particles with an electron microscope or an optical microscope, calculating an average value of the particle size of each solder particle, or performing a laser diffraction particle size distribution measurement. Is required.

  The coefficient of variation (CV value) of the solder particle diameter is preferably 5% or more, more preferably 10% or more, preferably 40% or less, more preferably 30% or less. When the coefficient of variation of the particle diameter of the solder particles is not less than the above lower limit and not more than the above upper limit, the solder can be more efficiently arranged on the electrode. However, the CV value of the particle diameter of the solder particles may be less than 5%.

  The coefficient of variation (CV value) can be measured as follows.

CV value (%) = (ρ / Dn) × 100
ρ: Standard deviation of particle diameter of solder particles Dn: Average value of particle diameter of solder particles

  The shape of the solder particles is not particularly limited. The solder particles may have a spherical shape or a shape other than a spherical shape such as a flat shape.

  The content of the solder particles in 100% by weight of the conductive material is preferably 40% by weight or more, more preferably 45% by weight or more, still more preferably 55% by weight or more, particularly preferably 60% by weight or more, preferably It is 90 weight% or less, More preferably, it is 85 weight% or less, More preferably, it is 80 weight% or less. When the content of the solder particles is not less than the above lower limit and not more than the above upper limit, it is possible to more efficiently arrange the solder on the electrodes, and it is easy to dispose a lot of solder between the electrodes. Reliability and insulation reliability can be further improved effectively.

Conductive particles other than solder particles (conductive particles X):
The conductive particles may be conductive particles other than the above-described solder particles (hereinafter, conductive particles other than the solder particles may be referred to as conductive particles X). The conductive particles X may be metal particles. Examples of the metal particles include metal particles as substrate particles described later. The conductive particles X may have base particles and conductive portions arranged on the surface of the base particles. The conductive particles X preferably include solder in the conductive part. The conductive portion may have a single layer structure or a multilayer structure of two or more layers. The conductive particle X includes a base particle, a second conductive part disposed on the surface of the base particle, and a first conductive part disposed on the outer surface of the second conductive part. May be provided.

  Hereinafter, other details of the conductive particles X will be described.

(Base particle)
Examples of the substrate particles include resin particles, inorganic particles excluding metal particles, organic-inorganic hybrid particles, and metal particles. The substrate particles are preferably substrate particles excluding metal particles, and more preferably resin particles, inorganic particles excluding metal particles, or organic-inorganic hybrid particles. The base particle may be a core-shell particle including a core and a shell disposed on the surface of the core. The core may be an organic core, and the shell may be an inorganic shell.

  Various organic materials are suitably used as the material for the resin particles. Examples of the material for the resin particles include polyolefin resins such as polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyvinylidene chloride, polyisobutylene, and polybutadiene; acrylic resins such as polymethyl methacrylate and polymethyl acrylate; 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, polyethylene terephthalate, polysulfone, polyphenylene oxide, polyacetal, Polyimide, polyamideimide, polyetheretherketone, poly Polyether sulfone, divinyl benzene polymer, and divinylbenzene copolymer, and the like. Examples of the divinylbenzene copolymer include divinylbenzene-styrene copolymer and divinylbenzene- (meth) acrylic acid ester copolymer. Since the hardness of the resin particles can be easily controlled within a suitable range, the material of the resin particles is a polymer obtained by polymerizing one or more polymerizable monomers having an ethylenically unsaturated group. Is preferred.

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

  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; Methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, cetyl (meth) acrylate, stearyl (meth) acrylate, Alkyl (meth) acrylate compounds such as cyclohexyl (meth) acrylate and isobornyl (meth) acrylate; 2-hydroxyethyl (meth) acrylate, glycerol (meth) acrylate, polyoxyethylene (meth) acrylate, and glycidyl (meth) Oxygen atom-containing (meth) acrylate compounds such as acrylate; Nitrile-containing monomers such as (meth) acrylonitrile; Vinyl ether compounds such as methyl vinyl ether, ethyl vinyl ether, and propyl vinyl ether; Vinyl acetate, vinyl butyrate, vinyl laurate, and stearin Acid vinyl ester compounds such as vinyl acid; unsaturated hydrocarbons such as ethylene, propylene, isoprene, and butadiene; trifluoromethyl (meth) acrylate, pentafluoroethyl (meth) acrylate, vinyl chloride, vinyl fluoride, and chlorostyrene And halogen-containing monomers such as

  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) acrylate compounds such as acrylate, (poly) tetramethylene glycol di (meth) acrylate, and 1,4-butanediol di (meth) acrylate; triallyl (iso) silane Silane-containing single quantities such as nurate, triallyl trimellitate, divinylbenzene, diallyl phthalate, diallylacrylamide, diallyl ether, and γ- (meth) acryloxypropyltrimethoxysilane, trimethoxysilylstyrene, and vinyltrimethoxysilane Examples include the body.

  The term “(meth) acrylate” refers to acrylate and methacrylate. The term “(meth) acryl” refers to acrylic and methacrylic. The term “(meth) acryloyl” refers to acryloyl and methacryloyl.

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

  The organic-inorganic hybrid particles are preferably core-shell type organic-inorganic hybrid particles having a core and a shell disposed on the surface of the core. The core is preferably an organic core. The shell is preferably an inorganic shell. From the viewpoint of effectively reducing the connection resistance between the electrodes, the base material particles are preferably organic-inorganic hybrid particles having an organic core and an inorganic shell disposed on the surface of the organic core.

  Examples of the material for the organic core include the material for the resin particles described above.

  Examples of the material for the inorganic shell include the inorganic materials mentioned as the material for the base material particles. The material of the inorganic shell is preferably silica. The inorganic shell is preferably formed on the surface of the core by forming a metal alkoxide into a shell-like material by a sol-gel method and then firing the shell-like material. The metal alkoxide is preferably a silane alkoxide. The inorganic shell is preferably formed of a silane alkoxide.

  When the base particles are metal particles, examples of the metal that is a material of the metal particles include silver, copper, nickel, silicon, gold, tin, and titanium.

  The particle diameter of the substrate particles is preferably 0.5 μm or more, more preferably 1 μm or more, further preferably 3 μm or more, preferably 100 μm or less, more preferably 60 μm or less, and even more preferably 50 μm or less. When the particle diameter of the substrate particles is not less than the above lower limit and not more than the above upper limit, the solder can be more efficiently arranged on the electrode. Further, when forming the conductive portion on the surface of the base particle, it becomes difficult to aggregate, and the aggregated conductive particle X is difficult to be formed.

  The particle diameter of the substrate particles is particularly preferably 5 μm or more and 40 μm or less. When the particle diameter of the substrate particles is in the range of 5 μm or more and 40 μm or less, the solder can be arranged more efficiently on the electrode.

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

  The particle diameter of the base particle indicates a number average particle diameter. The particle diameter of the substrate particles is determined using a particle size distribution measuring device or the like. The particle diameter of the substrate particles is preferably determined by observing 50 arbitrary substrate particles with an electron microscope or an optical microscope and calculating an average value. In the case of measuring the particle diameter of the base particle in the conductive particle X, for example, it can be measured as follows.

  An embedded resin for inspecting conductive particles X is prepared by adding and dispersing in “Technobit 4000” manufactured by Kulzer so that the content of the conductive particles X is 30% by weight. A cross section of the conductive particles X is cut out using an ion milling device ("IM4000" manufactured by Hitachi High-Technologies Corporation) so as to pass through the vicinity of the center of the conductive particles X dispersed in the inspection embedding resin. Then, using a field emission scanning electron microscope (FE-SEM), the image magnification is set to 25000 times, 50 conductive particles X are randomly selected, and base particles of each conductive particle X Observe. The particle diameter of the base particle in each conductive particle X is measured, and arithmetically averaged to obtain the particle diameter of the base particle.

(Conductive part)
The method for forming the conductive part on the surface of the base particle and the method for forming the first conductive part on the surface of the base particle or the surface of the second conductive part are not particularly limited. Examples of the method for forming the conductive part include a method by electroless plating, a method by electroplating, a method by physical collision, a method by mechanochemical reaction, a method by physical vapor deposition or physical adsorption, and a metal powder or Examples thereof include a method of coating the surface of the substrate particles with a paste containing a metal powder and a binder. The method for forming the conductive part is preferably a method by electroless plating, electroplating or physical collision. Examples of the method by physical vapor deposition include methods such as vacuum vapor deposition, ion plating, and ion sputtering. Further, in the method based on the physical collision, for example, a sheeter composer (manufactured by Tokuju Kogakusha Co., Ltd.) or the like is used.

  The melting point of the substrate particles is preferably higher than the melting point of the conductive part. The melting point of the substrate particles is preferably higher than 160 ° C, more preferably higher than 300 ° C, still more preferably higher than 400 ° C, and particularly preferably higher than 450 ° C. The melting point of the substrate particles may be less than 400 ° C. The melting point of the substrate particles may be 160 ° C. or less. The softening point of the substrate particles is preferably 260 ° C. or higher. The softening point of the substrate particles may be less than 260 ° C.

  The conductive part preferably contains a metal. The metal which comprises the said electroconductive part is not specifically limited. Examples of the metal include gold, silver, copper, platinum, palladium, zinc, lead, aluminum, cobalt, indium, nickel, chromium, titanium, antimony, bismuth, germanium and cadmium, and alloys thereof. In addition, tin-doped indium oxide (ITO) or solder may be used as the metal. As for the said metal, only 1 type may be used and 2 or more types may be used together.

  The conductive particles X may have a single layer solder portion. The conductive particles X may have a single-layer conductive portion, or may have a plurality of layers of conductive portions (first conductive portion and second conductive portion). That is, in the conductive particle X, two or more conductive portions may be stacked. When the conductive part has two or more layers, the conductive particles X may have solder on the outer surface portion of the conductive part.

  The solder is preferably a solder having the same composition as the solder particles described above.

  The low melting point metal constituting the solder is not particularly limited. The low melting point metal is preferably a low melting point metal constituting the solder particles described above.

  The melting point of the second conductive part is preferably higher than the melting point of the first conductive part. The melting point of the second conductive part is preferably more than 160 ° C, more preferably more than 300 ° C, still more preferably more than 400 ° C, still more preferably more than 450 ° C, particularly preferably more than 500 ° C, Most preferably above 600 ° C. Since the first conductive portion has a low melting point, it melts at the time of conductive connection. It is preferable that the second conductive portion does not melt during conductive connection. The first conductive part is preferably a solder part, and is preferably used by melting the first conductive part, and the first conductive part is melted and the second conductive part is used. It is preferably used without melting. When the melting point of the second conductive part is higher than the melting point of the first conductive part, only the first conductive part is melted without melting the second conductive part during conductive connection. be able to.

  The absolute value of the difference between the melting point of the first conductive part and the melting point of the second conductive part exceeds 0 ° C, preferably 5 ° C or higher, more preferably 10 ° C or higher, and even more preferably 30 ° C or higher. Particularly preferably, it is 50 ° C. or higher, and most preferably 100 ° C. or higher.

  The second conductive part preferably contains a metal. The metal which comprises the said 2nd electroconductive part is not specifically limited. Examples of the metal include gold, silver, copper, platinum, palladium, zinc, lead, aluminum, cobalt, indium, nickel, chromium, titanium, antimony, bismuth, germanium and cadmium, and alloys thereof. Further, tin-doped indium oxide (ITO) may be used as the metal. As for the said metal, only 1 type may be used and 2 or more types may be used together.

  The second conductive part is preferably a nickel layer, a palladium layer, a copper layer, or a gold layer, more preferably a nickel layer, a gold layer, or a copper layer, and even more preferably a copper layer. The conductive particles X preferably have a nickel layer, a palladium layer, a copper layer, or a gold layer, more preferably have a nickel layer, a gold layer, or a copper layer, and more preferably have a copper layer. By using the conductive particles X having these preferable conductive parts for the connection between the electrodes, the solder can be arranged more efficiently between the electrodes.

  The thickness of the first conductive part is preferably 0.005 μm or more, more preferably 0.01 μm or more, preferably 10 μm or less, more preferably 1 μm or less, and still more preferably 0.3 μm or less. When the thickness of the first conductive portion is not less than the above lower limit and not more than the above upper limit, the solder can be more efficiently disposed on the electrode, and the conduction reliability and the connection reliability can be further effectively improved. be able to.

  The particle diameter of the conductive particles X is preferably 1 μm or more, more preferably 2 μm or more, preferably 30 μm or less, more preferably 20 μm or less. When the particle diameter of the conductive particles X is not less than the above lower limit and not more than the above upper limit, the solder can be arranged more efficiently on the electrode, and the conduction reliability and the connection reliability can be more effectively improved. Can be increased. The particle diameter of the conductive particles X is particularly preferably 10 μm or less. When the particle diameter of the conductive particles X is 10 μm or less, the solder can be more efficiently disposed on the electrode, and the conduction reliability and the connection reliability can be further effectively improved.

  The particle diameter of the conductive particles X is preferably an average particle diameter, and more preferably a number average particle diameter. The average particle diameter of the conductive particles X is obtained, for example, by observing 50 arbitrary conductive particles X with an electron microscope or an optical microscope, calculating an average value, or performing laser diffraction particle size distribution measurement. .

  The CV value of the particle diameter of the conductive particles X is preferably 5% or more, more preferably 10% or more, preferably 40% or less, more preferably 30% or less. When the CV value of the particle diameter is not less than the above lower limit and not more than the above upper limit, the solder can be more efficiently arranged on the electrode. However, the CV value of the particle diameter of the conductive particles X may be less than 5%.

  The CV value (coefficient of variation) of the particle diameter of the conductive particles X can be measured as follows.

CV value (%) = (ρ / Dn) × 100
ρ: Standard deviation of particle diameter of conductive particle X Dn: Average value of particle diameter of conductive particle X

  The shape of the conductive particles X is not particularly limited. The shape of the conductive particles X may be spherical, or may be a shape other than a spherical shape such as a flat shape.

  The content of the conductive particles X in 100% by weight of the conductive material is preferably 40% by weight or more, more preferably 45% by weight or more, still more preferably 55% by weight or more, and particularly preferably 60% by weight or more. , Preferably 90% by weight or less, more preferably 85% by weight or less, and still more preferably 80% by weight or less. When the content of the conductive particles X is not less than the above lower limit and not more than the above upper limit, it is possible to more efficiently arrange solder on the electrodes, and it is easy to dispose much solder between the electrodes. In addition, the conduction reliability and the connection reliability can be further effectively improved.

(Thermosetting component)
The conductive material includes a thermosetting component. The thermosetting component includes a thermosetting compound. The thermosetting component does not contain or contain a thermosetting agent. The thermosetting component may or may not contain a thermosetting agent. In order to cure the conductive material even better, the conductive material preferably contains a thermosetting compound and a thermosetting agent as the thermosetting component. In order to cure the conductive material even better, the conductive material preferably contains a curing accelerator as a thermosetting component.

(Thermosetting component: thermosetting compound)
The thermosetting compound is not particularly limited. Examples of the thermosetting compound include oxetane compounds, epoxy compounds, episulfide compounds, (meth) acrylic compounds, phenolic compounds, amino compounds, unsaturated polyester compounds, polyurethane compounds, silicone compounds, and polyimide compounds. From the viewpoint of further improving the curability and viscosity of the conductive material, from the viewpoint of more effectively increasing the conduction reliability, and from the viewpoint of increasing the insulation reliability more effectively, an epoxy compound or an episulfide compound is preferable. An epoxy compound is more preferable. The thermosetting compound preferably contains an epoxy compound. As for the said thermosetting compound, only 1 type may be used and 2 or more types may be used together.

  The epoxy compound is a compound having at least one epoxy group. Examples of the epoxy compounds include bisphenol A type epoxy compounds, bisphenol F type epoxy compounds, bisphenol S type epoxy compounds, phenol novolac type epoxy compounds, biphenyl type epoxy compounds, biphenyl novolac type epoxy compounds, biphenol type epoxy compounds, and naphthalene type epoxy compounds. Fluorene type epoxy compound, phenol aralkyl type epoxy compound, naphthol aralkyl type epoxy compound, dicyclopentadiene type epoxy compound, anthracene type epoxy compound, epoxy compound having adamantane skeleton, epoxy compound having tricyclodecane skeleton, naphthylene ether type Examples thereof include an epoxy compound and an epoxy compound having a triazine nucleus in the skeleton. As for the said epoxy compound, only 1 type may be used and 2 or more types may be used together.

  The epoxy compound is liquid or solid at normal temperature (23 ° C.), and when the epoxy compound is solid at normal temperature, the melting temperature of the epoxy compound is preferably equal to or lower than the melting point of the solder. By using the above-mentioned preferable epoxy compound, the first connection target member and the second connection are high when the connection target member is pasted and when the viscosity is high and acceleration is applied by impact such as conveyance. The positional deviation with respect to the target member can be suppressed. Furthermore, the viscosity of the conductive material can be greatly reduced by heat at the time of curing, and the solder can be efficiently aggregated.

  From the viewpoint of further increasing the insulation reliability more effectively and from the viewpoint of increasing the conduction reliability more effectively, the thermosetting compound preferably contains an epoxy compound.

  From the viewpoint of more efficiently arranging the solder on the electrode, the thermosetting compound preferably includes a thermosetting compound having a polyether skeleton.

  Examples of the thermosetting compound having a polyether skeleton include a compound having a glycidyl ether group at both ends of an alkyl chain having 3 to 12 carbon atoms, and a polyether skeleton having 2 to 4 carbon atoms. Examples thereof include polyether type epoxy compounds having structural units in which 2 to 10 are bonded continuously.

  From the viewpoint of further effectively increasing the heat resistance of the cured product, the thermosetting compound preferably includes a thermosetting compound having an isocyanuric skeleton.

  Examples of the thermosetting compound having the isocyanuric skeleton include triisocyanurate type epoxy compounds, and the TEPIC series (TEPIC-G, TEPIC-S, TEPIC-SS, TEPIC-HP, TEPIC-L, manufactured by Nissan Chemical Industries, Ltd.) TEPIC-PAS, TEPIC-VL, TEPIC-UC) and the like.

  The SP value of the thermosetting compound is preferably 20 or more, more preferably 22 or more, preferably 45 or less, more preferably 30 or less, and even more preferably 25 or less. When the SP value of the thermosetting compound is not less than the above lower limit and not more than the above upper limit, when the electrodes are electrically connected, the conduction reliability and the insulation reliability can be further effectively improved.

  The SP value of the thermosetting compound can be obtained from literature information, and can also be obtained by a Hansen or Hoy calculation method, a Fedors estimation method, or the like. The SP value of the thermosetting compound is preferably obtained by the Fedors estimation method.

  In 100% by weight of the conductive material, the content of the thermosetting compound is preferably 5% by weight or more, more preferably 10% by weight or more, further preferably 15% by weight or more, and preferably 90% by weight or less. Preferably it is 70 weight% or less, More preferably, it is 50 weight% or less, Most preferably, it is 30 weight% or less. When the content of the thermosetting compound is not less than the above lower limit and not more than the above upper limit, the solder can be disposed more efficiently on the electrodes, and the insulation reliability between the electrodes can be further effectively improved. Further, the conduction reliability between the electrodes can be further effectively improved. From the viewpoint of more effectively increasing the impact resistance, it is preferable that the content of the thermosetting compound is large.

  In 100% by weight of the conductive material, the content of the epoxy compound is preferably 5% by weight or more, more preferably 10% by weight or more, further preferably 15% by weight or more, preferably 90% by weight or less, more preferably It is 70% by weight or less, more preferably 50% by weight or less, and particularly preferably 30% by weight or less. When the content of the epoxy compound is not less than the above lower limit and not more than the above upper limit, the solder can be more efficiently arranged on the electrodes, and the insulation reliability between the electrodes can be further effectively improved, The conduction reliability between them can be further effectively improved. From the viewpoint of further improving the impact resistance, it is preferable that the content of the epoxy compound is large.

(Thermosetting component: thermosetting agent)
The said thermosetting agent is not specifically limited. The thermosetting agent thermosets the thermosetting compound. Examples of the thermosetting agent include imidazole curing agents, amine curing agents, phenol curing agents, polythiol curing agents and other thiol curing agents, acid anhydride curing agents, thermal cation initiators (thermal cation curing agents), and thermal radical generators. Is mentioned. As for the said thermosetting agent, only 1 type may be used and 2 or more types may be used together.

  The SP value of the thermosetting agent is preferably 19 or more, and preferably 25 or less. When the SP value of the thermosetting compound is not less than the above lower limit and not more than the above upper limit, when the electrodes are electrically connected, the conduction reliability and the insulation reliability can be further effectively improved.

  The SP value of the thermosetting agent can be obtained from literature information, and can also be obtained by a Hansen or Hoy calculation method, a Fedors estimation method, or the like. The SP value of the thermosetting agent is preferably obtained by Fedors' estimation method.

  From the viewpoint of allowing the conductive material to be cured more rapidly at a low temperature, the thermosetting agent is preferably an imidazole curing agent, a thiol curing agent, or an amine curing agent. Further, from the viewpoint of enhancing the storage stability when the thermosetting compound and the thermosetting agent are mixed, the thermosetting agent is preferably a latent curing agent. The latent curing agent is preferably a latent imidazole curing agent, a latent thiol curing agent, or a latent amine curing agent. In addition, the said thermosetting agent may be coat | covered with polymeric substances, such as a polyurethane resin or a polyester resin.

  The imidazole curing agent is not particularly limited. Examples of the imidazole curing agent include 2-methylimidazole, 2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2,4-diamino-6. -[2'-methylimidazolyl- (1 ')]-ethyl-s-triazine and 2,4-diamino-6- [2'-methylimidazolyl- (1')]-ethyl-s-triazine isocyanuric acid adducts 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2-phenyl-4-benzyl-5-hydroxymethylimidazole, 2-paratoluyl-4-methyl-5 -Hydroxymethylimidazole, 2-metatoluyl-4-methyl-5- Roxymethylimidazole, 2-metatoluyl-4,5-dihydroxymethylimidazole, 2-paratoluyl-4,5-dihydroxymethylimidazole, etc., the hydrogen at the 5-position of 1H-imidazole is a hydroxymethyl group and the hydrogen at the 2-position Examples thereof include an imidazole compound substituted with a phenyl group or a toluyl group.

  The thiol curing agent is not particularly limited. Examples of the thiol curing agent include trimethylolpropane tris-3-mercaptopropionate, pentaerythritol tetrakis-3-mercaptopropionate, and dipentaerythritol hexa-3-mercaptopropionate.

  The amine curing agent is not particularly limited. Examples of the amine curing agent include hexamethylenediamine, octamethylenediamine, decamethylenediamine, 3,9-bis (3-aminopropyl) -2,4,8,10-tetraspiro [5.5] undecane, bis (4 -Aminocyclohexyl) methane, metaphenylenediamine, diaminodiphenylsulfone and the like.

  The acid anhydride curing agent is not particularly limited and can be widely used as long as it is an acid anhydride used as a curing agent for a thermosetting compound such as an epoxy compound. Examples of the acid anhydride curing agent include phthalic anhydride, tetrahydrophthalic anhydride, trialkyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylbutenyltetrahydrophthalic anhydride. Phthalic acid anhydride, maleic anhydride, nadic anhydride, methyl nadic anhydride, glutaric anhydride, succinic anhydride, glycerin bistrimellitic anhydride monoacetate, and ethylene glycol bistrimellitic anhydride Acid anhydride curing agent, trifunctional acid anhydride curing agent such as trimellitic anhydride, pyromellitic anhydride, benzophenone tetracarboxylic anhydride, methylcyclohexene tetracarboxylic acid anhydride, polyazeline acid anhydride, etc. 4 or more functional acid anhydrides Curing agents.

  The thermal cation initiator is not particularly limited. Examples of the thermal cation initiator include iodonium cation curing agents, oxonium cation curing agents, and sulfonium cation curing agents. Examples of the iodonium-based cationic curing agent include bis (4-tert-butylphenyl) iodonium hexafluorophosphate. Examples of the oxonium-based cationic curing agent include trimethyloxonium tetrafluoroborate. Examples of the sulfonium-based cationic curing agent include tri-p-tolylsulfonium hexafluorophosphate.

  The thermal radical generator is not particularly limited. Examples of the thermal radical generator include azo compounds and organic peroxides. Examples of the azo compound include azobisisobutyronitrile (AIBN). Examples of the organic peroxide include di-tert-butyl peroxide and methyl ethyl ketone peroxide.

  The reaction initiation temperature of the thermosetting agent is preferably 50 ° C. or higher, more preferably 70 ° C. or higher, further preferably 80 ° C. or higher, preferably 250 ° C. or lower, more preferably 200 ° C. or lower, and further preferably 150 ° C. Hereinafter, it is particularly preferably 140 ° C. or lower. When the reaction start temperature of the thermosetting agent is not less than the above lower limit and not more than the above upper limit, the solder is more efficiently disposed on the electrode. The reaction start temperature of the thermosetting agent is particularly preferably 80 ° C. or higher and 140 ° C. or lower.

  From the viewpoint of more efficiently arranging the solder on the electrode, the reaction initiation temperature of the thermosetting agent is preferably higher than the melting point of the solder particles, more preferably 5 ° C or higher, more preferably 10 ° C. More preferably, it is higher.

  The reaction start temperature of the thermosetting agent means a temperature at which the exothermic peak of DSC starts to rise.

  The content of the thermosetting agent is not particularly limited. The content of the thermosetting agent with respect to 100 parts by weight of the thermosetting compound is preferably 0.01 parts by weight or more, more preferably 1 part by weight or more, preferably 200 parts by weight or less, more preferably 100 parts by weight or less, more preferably 75 parts by weight or less. When the content of the thermosetting agent is not less than the above lower limit, it is easy to sufficiently cure the conductive material. When the content of the thermosetting agent is not more than the above upper limit, it is difficult for an excess thermosetting agent that did not participate in curing after curing to remain, and the heat resistance of the cured product is further enhanced.

(Thermosetting component: curing accelerator)
The conductive material may contain a curing accelerator. The said hardening accelerator is not specifically limited. The curing accelerator preferably acts as a curing catalyst in the reaction between the thermosetting compound and the thermosetting agent. The curing accelerator preferably acts as a curing catalyst in the reaction with the thermosetting compound. As for the said hardening accelerator, only 1 type may be used and 2 or more types may be used together.

  Examples of the curing accelerator include phosphonium salts, tertiary amines, tertiary amine salts, quaternary onium salts, tertiary phosphines, crown ether complexes, and phosphonium ylides. Specifically, the curing accelerator includes imidazole compound, isocyanurate of imidazole compound, dicyandiamide, dicyandiamide derivative, melamine compound, melamine compound derivative, diaminomaleonitrile, diethylenetriamine, triethylenetetramine, tetraethylenepentamine. , Amine compounds such as bis (hexamethylene) triamine, triethanolamine, diaminodiphenylmethane, organic acid dihydrazide, 1,8-diazabicyclo [5,4,0] undecene-7, 3,9-bis (3-aminopropyl) -2,4,8,10-tetraoxaspiro [5,5] undecane, boron trifluoride, and triphenylphosphine, tricyclohexylphosphine, tributylphosphine and methyldiphenylphosphine And the like organic phosphorus compounds.

  The phosphonium salt is not particularly limited. Examples of the phosphonium salt include tetranormal butylphosphonium bromide, tetranormal butylphosphonium OO diethyldithiophosphoric acid, methyltributylphosphonium dimethyl phosphate, tetranormal butylphosphonium benzotriazole, tetranormal butylphosphonium tetrafluoroborate, and tetranormal butyl. Examples thereof include phosphonium tetraphenylborate.

  The content of the curing accelerator is appropriately selected so that the thermosetting compound is cured well. The content of the curing accelerator with respect to 100 parts by weight of the thermosetting compound is preferably 0.5 parts by weight or more, more preferably 0.8 parts by weight or more, preferably 10 parts by weight or less, more preferably 8 parts by weight. Less than parts by weight. When the content of the curing accelerator is not less than the above lower limit and not more than the above upper limit, the thermosetting compound can be cured well.

(Active agent)
The conductive material includes an activator. The activator removes the oxide film of the conductive particles. The activator is an oxide film removing agent. The activator is not particularly limited. As the activator, a flux generally used for soldering or the like can be used.

  Examples of the flux include zinc chloride, a mixture of zinc chloride and an inorganic halide, a mixture of zinc chloride and an inorganic acid, a molten salt, phosphoric acid, a derivative of phosphoric acid, an organic halide, hydrazine, an amine compound, an organic acid, and Examples include pine resin. As for the said flux, only 1 type may be used and 2 or more types may be used together.

  Examples of the molten salt include ammonium chloride. Examples of the organic acid include lactic acid, citric acid, stearic acid, glutamic acid, and glutaric acid. Examples of the pine resin include activated pine resin and non-activated pine resin. The flux is preferably an organic acid having two or more carboxyl groups or pine resin. The flux may be an organic acid having two or more carboxyl groups, or pine resin. By using an organic acid having two or more carboxyl groups, pine resin, the conduction reliability between the electrodes is further enhanced.

  Examples of the organic acid having two or more carboxyl groups include succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, and sebacic acid.

  Examples of the amine compound include cyclohexylamine, dicyclohexylamine, benzylamine, benzhydrylamine, imidazole, benzimidazole, phenylimidazole, carboxybenzimidazole, benzotriazole, and carboxybenzotriazole.

  The rosin is a rosin composed mainly of abietic acid. Examples of the rosins include abietic acid and acrylic modified rosin. The flux is preferably a rosin, and more preferably abietic acid. By using this preferable flux, the conduction reliability between the electrodes is further enhanced.

  The active temperature (melting point) of the activator is preferably −50 ° C. or higher, more preferably −30 ° C. or higher, preferably 30 ° C. or lower, more preferably 0 ° C. or lower. When the activation temperature of the activator is not less than the above lower limit and not more than the above upper limit, the effect of the activator is more effectively exhibited, and the conduction reliability between the electrodes is further enhanced.

  The activator is preferably liquid at normal temperature (25 ° C.). When the activator is liquid at room temperature (25 ° C.), the conduction reliability between the electrodes is further enhanced.

  The activator that is liquid at room temperature (25 ° C.) is not particularly limited. The activator is preferably an acidic phosphate compound. Examples of commercially available acidic phosphate compounds include ethyl acid phosphate and butyl acid phosphate (all of which are manufactured by Johoku Chemical Industry Co., Ltd.).

  Moreover, it is preferable that the boiling point of the said activator is 200 degrees C or less.

  The activator may be dispersed in the conductive material or may adhere to the surface of the conductive particles.

  From the viewpoint of further increasing the insulation reliability more effectively and from the viewpoint of increasing the conduction reliability more effectively, the activator is preferably a salt of an acid compound and a base compound.

  The acid compound is preferably an organic compound having a carboxyl group. Examples of the acid compound include aliphatic carboxylic acids such as malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, citric acid, malic acid, and cyclic aliphatic carboxylic acid. Examples thereof include cyclohexyl carboxylic acid, 1,4-cyclohexyl dicarboxylic acid, aromatic carboxylic acid such as isophthalic acid, terephthalic acid, trimellitic acid, and ethylenediaminetetraacetic acid. From the viewpoint of more effectively increasing the insulation reliability and further improving the conduction reliability more effectively, the acid compound is preferably glutaric acid, cyclohexyl carboxylic acid, or adipic acid.

  The base compound is preferably an organic compound having an amino group. Examples of the base compound include diethanolamine, triethanolamine, methyldiethanolamine, ethyldiethanolamine, cyclohexylamine, dicyclohexylamine, benzylamine, benzhydrylamine, 2-methylbenzylamine, 3-methylbenzylamine, 4-tert-butylbenzylamine. N-methylbenzylamine, N-ethylbenzylamine, N-phenylbenzylamine, N-tert-butylbenzylamine, N-isopropylbenzylamine, N, N-dimethylbenzylamine, imidazole compounds, and triazole compounds. . From the viewpoint of more effectively increasing the insulation reliability and the viewpoint of further effectively increasing the conduction reliability, the base compound is preferably benzylamine.

  When the electrodes are electrically connected, the acid value of the activator is preferably 280 mgKOH / g or more, more preferably 340 mgKOH / g, from the viewpoint of further effectively increasing the conduction reliability and the insulation reliability. It is above, Preferably it is 580 mgKOH / g or less, More preferably, it is 460 mgKOH / g or less.

  The acid value can be measured as follows.

  1 g of activator is added to 36 g of acetone and dispersed with ultrasound for 1 minute. Thereafter, phenolphthalein is used as an indicator and titrated with a 0.1 mol / L potassium hydroxide ethanol solution.

  The SP value of the activator is preferably 20 or more, more preferably 25 or more, and preferably 28 or less. When the SP value of the activator is not less than the above lower limit and not more than the above upper limit, when the electrodes are electrically connected, the conduction reliability and the insulation reliability can be further effectively improved.

  The SP value of the activator can be obtained from literature information, or can be obtained by a Hansen or Hoy calculation method, a Fedors estimation method, or the like. The SP value of the activator is preferably obtained by Fedors' estimation method.

  In the conductive material according to the present invention, when the thermosetting component does not contain the thermosetting agent, the absolute value of the difference between the SP value of the thermosetting compound and the SP value of the activator is 2 It is as follows. The absolute value of the difference between the SP value of the thermosetting compound and the SP value of the activator is preferably 1.5 or less, more preferably 1 or less. When the absolute value of the difference between the SP value of the thermosetting compound and the SP value of the activator is not more than the upper limit, when the electrodes are electrically connected, the conduction reliability and the insulation reliability are further improved. It can be increased more effectively.

  In the conductive material according to the present invention, when the thermosetting component contains the thermosetting agent, the SP value of the mixture (M) of the thermosetting compound and the thermosetting agent, and the SP of the activator. The absolute value of the difference from the value is 2 or less. The absolute value of the difference between the SP value of the mixture (M) and the SP value of the active agent is preferably 1.5 or less, more preferably 1 or less. When the absolute value of the difference between the SP value of the mixture (M) and the SP value of the activator is not more than the upper limit, when the electrodes are electrically connected, the conduction reliability and the insulation reliability are improved. It can be increased even more effectively.

  The SP value of the mixture (M) of the thermosetting compound and the thermosetting agent can be calculated by the following formula.

SP value of mixture (M) of thermosetting compound and thermosetting agent = SP1 × φ1 + SP2 × φ2
SP1: SP value of the thermosetting compound φ1: Volume fraction of the thermosetting compound in the mixture (M) of the thermosetting compound and the thermosetting agent SP2: SP value of the thermosetting agent φ2: With the thermosetting compound Volume fraction of thermosetting agent in mixture (M) with thermosetting agent

  When two types of thermosetting compounds are used, the SP value of the thermosetting compound can be calculated by the following formula.

SP value of thermosetting compound (the whole thermosetting compound) = SPT1 × φT1 + SPT2 × φT2
SPT1: SP value of the first thermosetting compound φT1: Volume fraction of the first thermosetting compound in the two thermosetting compounds SPT2: SP value of the second thermosetting compound φT2 : Volume fraction of the second thermosetting compound in the two thermosetting compounds

  When n (n is an integer of 3 or more) types of thermosetting compounds are used, the SP value of the thermosetting compound can be calculated by the following formula.

SP value of thermosetting compound (whole thermosetting compound) = SPT1 × φT1 + SPT2 × φT2 +... + SPTn × φTn)
SPT1: SP value of the first thermosetting compound φT1: Volume fraction of the first thermosetting compound in the n thermosetting compounds SPT2: SP value of the second thermosetting compound φT2 : Volume fraction of second kind of thermosetting compound in n kinds of thermosetting compounds (when n is 4, the third kind is omitted; when n is 5 or more, the third kind to n- (The first type is omitted)
SPTn: SP value of the nth thermosetting compound φTn: Volume fraction of the nth thermosetting compound in the nth thermosetting compound

  When two types of thermosetting agents are used, the SP value of the thermosetting agent can be calculated by the following formula.

SP value of thermosetting agent (entire thermosetting agent) = SPH1 × φH1 + SPH2 × φH2
SPH1: SP value of the first kind of thermosetting agent φH1: Volume fraction of the first kind of thermosetting agent in the two kinds of thermosetting agents SPH2: SP value of the second kind of thermosetting agent φH2: Two kinds Volume fraction of the second kind of thermosetting agent

  When n (n is an integer of 3 or more) types of thermosetting agents are used, the SP value of the thermosetting agent can be calculated by the following formula.

SP value of thermosetting agent (whole thermosetting agent) = SPH1 × φH1 + SPH2 × φH2 +... + SPHn × φHn)
SPH1: SP value of the first type of thermosetting agent φH1: Volume fraction of the first type of thermosetting agent in the n types of thermosetting agents SPH2: SP value of the second type of thermosetting agent φH2: n types The volume fraction of the second type of thermosetting agent in the thermosetting agent of (... when n is 4, the third type is omitted; when n is 5 or more, the third type to the n-1 type are (Omitted)
SPHn: SP value of the nth thermosetting agent φHn: Volume fraction of the nth thermosetting agent in the nth thermosetting agent

  The content of the activator with respect to 100 parts by weight of the thermosetting compound is preferably 1 part by weight or more, more preferably 5 parts by weight or more, preferably 20 parts by weight or less, more preferably 10 parts by weight or less. . When the content of the activator is not less than the above lower limit and not more than the above upper limit, it becomes more difficult to form an oxide film on the surface of the solder and the electrode, and moreover, the oxide film formed on the surface of the solder and the electrode is further reduced. It can be removed more effectively. When the content of the activator is not less than the above lower limit and not more than the above upper limit, the conduction reliability and the insulation reliability can be further effectively improved when the electrodes are electrically connected.

  The content of the activator in 100% by weight of the conductive material is preferably 0.5% by weight or more, preferably 30% by weight or less, more preferably 25% by weight or less. When the content of the activator is not less than the above lower limit and not more than the above upper limit, it becomes more difficult to form an oxide film on the surface of the solder and the electrode, and moreover, the oxide film formed on the surface of the solder and the electrode is further reduced. It can be removed more effectively. When the content of the activator is not less than the above lower limit and not more than the above upper limit, the conduction reliability and the insulation reliability can be further effectively improved when the electrodes are electrically connected.

(Filler)
The conductive material according to the present invention may contain a filler. The filler may be an organic filler or an inorganic filler. When the conductive material contains a filler, the solder can be uniformly aggregated over all the electrodes of the substrate.

  It is preferable that the conductive material does not contain the filler or contains the filler at 5% by weight or less. When using the said thermosetting compound, solder becomes easy to move on an electrode, so that there is little content of a filler.

  The content of the filler in 100% by weight of the conductive material is preferably 0% by weight (not contained) or more, preferably 5% by weight or less, more preferably 2% by weight or less, and further preferably 1% by weight or less. is there. When the content of the filler is not less than the above lower limit and not more than the above upper limit, the solder is more uniformly arranged on the electrode.

(Other ingredients)
The conductive material may be, for example, a filler, an extender, a softener, a plasticizer, a thixotropic agent, a leveling agent, a polymerization catalyst, a curing catalyst, a colorant, an antioxidant, a heat stabilizer, and a light stabilizer. In addition, various additives such as ultraviolet absorbers, lubricants, antistatic agents and flame retardants may be contained.

(Connection structure and method of manufacturing connection structure)
The connection structure according to the present invention includes a first connection target member having a first electrode on the surface, a second connection target member having a second electrode on the surface, the first connection target member, A connecting portion connecting the second connection target member. In the connection structure according to the present invention, the material of the connection portion is the conductive material described above. In the connection structure according to the present invention, the first electrode and the second electrode are electrically connected by the connection portion.

  The manufacturing method of the connection structure which concerns on this invention comprises the process of arrange | positioning the said electrically-conductive material on the surface of the 1st connection object member which has a 1st electrode on the surface using the electrically conductive material mentioned above. In the method for manufacturing a connection structure according to the present invention, a second connection target member having a second electrode on a surface thereof is provided on the surface opposite to the first connection target member side of the conductive material. A step of disposing the first electrode and the second electrode so as to face each other. The manufacturing method of the connection structure according to the present invention connects the first connection target member and the second connection target member by heating the conductive material to a temperature equal to or higher than the melting point of the conductive particles. A step of forming a connection portion with the conductive material and electrically connecting the first electrode and the second electrode with the connection portion is provided.

  In the connection structure and the manufacturing method of the connection structure according to the present invention, since a specific conductive material is used, the solder is likely to gather between the first electrode and the second electrode, and the solder is an electrode (line). Can be efficiently placed on top. In addition, a part of the solder is difficult to be disposed in a region (space) where no electrode is formed, and the amount of solder disposed in a region where no electrode is formed can be considerably reduced. Therefore, the conduction reliability between the first electrode and the second electrode can be improved. In addition, it is possible to prevent electrical connection between laterally adjacent electrodes that should not be connected, and to improve insulation reliability.

  Moreover, in order to dispose the solder efficiently on the electrode and to considerably reduce the amount of the solder disposed in the region where the electrode is not formed, the conductive material is not a conductive film but a conductive paste. It is preferable.

  The thickness of the solder part between the electrodes is preferably 10 μm or more, more preferably 20 μm or more, preferably 100 μm or less, more preferably 80 μm or less. The solder wetted area on the surface of the electrode (area where the solder is in contact with 100% of the exposed area of the electrode) is preferably 50% or more, more preferably 70% or more, and preferably 100% or less.

  In the method for manufacturing a connection structure according to the present invention, in the step of arranging the second connection target member and the step of forming the connection portion, no pressure is applied, and the second connection is applied to the conductive material. The weight of the target member is preferably added. In the method for manufacturing a connection structure according to the present invention, in the step of disposing the second connection target member and the step of forming the connection portion, the conductive material has a weight force of the second connection target member. It is preferable not to apply a pressure higher than. In these cases, the uniformity of the amount of solder can be further enhanced in the plurality of solder portions. Furthermore, the thickness of the solder portion can be increased more effectively, so that a large amount of solder is easily collected between the electrodes, and the solder can be arranged more efficiently on the electrodes (lines). Further, a part of the solder is difficult to be disposed in a region (space) where no electrode is formed, and the amount of solder disposed in a region where no electrode is formed can be further reduced. Therefore, the conduction reliability between the electrodes can be further enhanced. In addition, the electrical connection between the laterally adjacent electrodes that should not be connected can be further prevented, and the insulation reliability can be further improved.

  Moreover, if a conductive paste is used instead of a conductive film, it becomes easy to adjust the thickness of the connection part and the solder part depending on the amount of the conductive paste applied. On the other hand, in the conductive film, in order to change or adjust the thickness of the connecting portion, it is necessary to prepare a conductive film having a different thickness or to prepare a conductive film having a predetermined thickness. There is. Moreover, in the conductive film, compared with the conductive paste, the melt viscosity of the conductive film cannot be sufficiently lowered at the melting temperature of the solder, and the aggregation of the solder tends to be hindered.

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

  FIG. 1 is a cross-sectional view schematically showing a connection structure obtained using a conductive material according to an embodiment of the present invention.

  The connection structure 1 shown in FIG. 1 is a connection that connects a first connection target member 2, a second connection target member 3, and the first connection target member 2 and the second connection target member 3. Part 4. The connection part 4 is formed of the conductive material described above. In the present embodiment, the conductive material includes a thermosetting component, a plurality of conductive particles, and an activator. The thermosetting component includes a thermosetting compound and a thermosetting agent. The conductive particles are solder particles. In the present embodiment, a conductive paste is used as the conductive material.

  The connection portion 4 includes a solder portion 4A in which a plurality of solder particles are gathered and joined to each other, and a cured product portion 4B in which a thermosetting compound is thermally cured.

  The first connection target member 2 has a plurality of first electrodes 2a on the surface (upper surface). The second connection target member 3 has a plurality of second electrodes 3a on the surface (lower surface). The first electrode 2a and the second electrode 3a are electrically connected by the solder portion 4A. Therefore, the first connection target member 2 and the second connection target member 3 are electrically connected by the solder portion 4A. In the connection portion 4, no solder particles are present in a region (cured product portion 4B portion) different from the solder portion 4A gathered between the first electrode 2a and the second electrode 3a. In an area different from the solder part 4A (hardened product part 4B part), there are no solder particles separated from the solder part 4A. If the amount is small, solder particles may exist in a region (cured product portion 4B portion) different from the solder portion 4A gathered between the first electrode 2a and the second electrode 3a.

  As shown in FIG. 1, in the connection structure 1, a plurality of solder particles gather between the first electrode 2 a and the second electrode 3 a, and after the plurality of solder particles melt, After the electrode surface wets and spreads, it solidifies to form the solder portion 4A. For this reason, the connection area of 4 A of solder parts and the 1st electrode 2a, and 4 A of solder parts, and the 2nd electrode 3a becomes large. That is, by using the solder particles, the solder portion 4A, the first electrode 2a, and the solder portion are compared with the case where the conductive outer surface is made of a metal such as nickel, gold or copper. The contact area between 4A and the second electrode 3a increases. This also increases the conduction reliability and connection reliability in the connection structure 1. In the case where the conductive material contains an activator, the activator is generally gradually deactivated by heating.

  In addition, in the connection structure 1 shown in FIG. 1, all the solder parts 4A are located in the area | region which the 1st, 2nd electrodes 2a and 3a oppose. The connection structure 1X of the modification shown in FIG. 3 is different from the connection structure 1 shown in FIG. 1 only in the connection portion 4X. The connection part 4X has the solder part 4XA and the hardened | cured material part 4XB. As in the connection structure 1X, most of the solder portions 4XA are located in regions where the first and second electrodes 2a and 3a are opposed to each other, and a part of the solder portion 4XA is first and second. You may protrude to the side from the area | region which electrode 2a, 3a has opposed. The solder part 4XA protruding laterally from the region where the first and second electrodes 2a and 3a are opposed is a part of the solder part 4XA and is not a solder particle separated from the solder part 4XA. In this embodiment, the amount of solder particles separated from the solder portion can be reduced, but the solder particles separated from the solder portion may be present in the cured product portion.

  If the amount of solder particles used is reduced, the connection structure 1 can be easily obtained. If the amount of the solder particles used is increased, it becomes easy to obtain the connection structure 1X.

  In connection structure 1, 1X, when the part which 1st electrode 2a and 2nd electrode 3a oppose in the lamination direction of 1st electrode 2a, connection part 4, 4X, and 2nd electrode 3a is seen In addition, it is preferable that the solder portions 4A and 4XA in the connection portions 4 and 4X are arranged in 50% or more of the area of 100% of the facing portion between the first electrode 2a and the second electrode 3a. . When the solder portions 4A and 4XA in the connection portions 4 and 4X satisfy the above-described preferable mode, the conduction reliability can be further improved.

  When the first electrode and the second electrode face each other in the stacking direction of the first electrode, the connection portion, and the second electrode, the first electrode and the second electrode It is preferable that the solder portion in the connecting portion is arranged in 50% or more of the area of 100% of the portion facing the two electrodes. When the first electrode and the second electrode face each other in the stacking direction of the first electrode, the connection portion, and the second electrode, the first electrode and the second electrode It is more preferable that the solder portion in the connection portion is disposed in 60% or more of 100% of the area of the portion facing the two electrodes. When the first electrode and the second electrode face each other in the stacking direction of the first electrode, the connection portion, and the second electrode, the first electrode and the second electrode More preferably, the solder portion in the connecting portion is arranged in 70% or more of the area of 100% of the portion facing the two electrodes. When the first electrode and the second electrode face each other in the stacking direction of the first electrode, the connection portion, and the second electrode, the first electrode and the second electrode It is particularly preferable that the solder portion in the connecting portion is disposed in 80% or more of 100% of the area facing the two electrodes. When the first electrode and the second electrode face each other in the stacking direction of the first electrode, the connection portion, and the second electrode, the first electrode and the second electrode It is most preferable that the solder portion in the connection portion is disposed in 90% or more of the area of 100% of the portion facing the two electrodes. When the solder part in the connection part satisfies the above-described preferable aspect, the conduction reliability can be further improved.

  When the portion where the first electrode and the second electrode face each other in the direction orthogonal to the stacking direction of the first electrode, the connection portion, and the second electrode is seen, It is preferable that 60% or more of the solder portion in the connection portion is disposed in a portion where the electrode and the second electrode face each other. When the portion where the first electrode and the second electrode face each other in the direction orthogonal to the stacking direction of the first electrode, the connection portion, and the second electrode is seen, More preferably, 70% or more of the solder portion in the connection portion is disposed in a portion where the electrode and the second electrode face each other. When the portion where the first electrode and the second electrode face each other in the direction orthogonal to the stacking direction of the first electrode, the connection portion, and the second electrode is seen, More preferably, 90% or more of the solder portion in the connection portion is disposed in a portion where the electrode and the second electrode face each other. When the portion where the first electrode and the second electrode face each other in the direction orthogonal to the stacking direction of the first electrode, the connection portion, and the second electrode is seen, It is particularly preferable that 95% or more of the solder portion in the connection portion is disposed at a portion where the electrode and the second electrode face each other. When the portion where the first electrode and the second electrode face each other in the direction orthogonal to the stacking direction of the first electrode, the connection portion, and the second electrode is seen, It is most preferable that 99% or more of the solder portion in the connection portion is disposed in a portion where the electrode and the second electrode face each other. When the solder part in the connection part satisfies the above-described preferable aspect, the conduction reliability can be further improved.

  Next, FIG. 2 illustrates an example of a method for manufacturing the connection structure 1 using the conductive material according to the embodiment of the present invention.

  First, the 1st connection object member 2 which has the 1st electrode 2a on the surface (upper surface) is prepared. Next, as shown in FIG. 2A, a thermosetting component 11B, solder particles 11A, and a conductive material 11 containing an activator are arranged on the surface of the first connection target member 2 (first). Process). The used conductive material 11 contains a thermosetting compound and a thermosetting agent as the thermosetting component 11B.

  The conductive material 11 is disposed on the surface of the first connection target member 2 on which the first electrode 2a is provided. After the conductive material 11 is disposed, the solder particles 11A are disposed both on the first electrode 2a (line) and on a region (space) where the first electrode 2a is not formed.

  The arrangement method of the conductive material 11 is not particularly limited, and examples thereof include application using a dispenser, screen printing, and ejection using an inkjet apparatus.

  Moreover, the 2nd connection object member 3 which has the 2nd electrode 3a on the surface (lower surface) is prepared. Next, as shown in FIG. 2B, in the conductive material 11 on the surface of the first connection target member 2, on the surface of the conductive material 11 opposite to the first connection target member 2 side, The 2nd connection object member 3 is arrange | positioned (2nd process). On the surface of the conductive material 11, the second connection target member 3 is disposed from the second electrode 3a side. At this time, the first electrode 2a and the second electrode 3a are opposed to each other.

  Next, the conductive material 11 is heated above the melting point of the solder particles 11A (third step). Preferably, the conductive material 11 is heated above the curing temperature of the thermosetting component 11B (thermosetting compound). At the time of this heating, the solder particles 11A that existed in the region where no electrode is formed gather between the first electrode 2a and the second electrode 3a (self-aggregation effect). When the conductive paste is used instead of the conductive film, the solder particles 11A are more effectively collected between the first electrode 2a and the second electrode 3a. Also, the solder particles 11A are melted and joined together. Further, the thermosetting component 11B is thermoset. As a result, as shown in FIG. 2C, the connection portion 4 that connects the first connection target member 2 and the second connection target member 3 is formed of the conductive material 11. The connection part 4 is formed of the conductive material 11, the solder part 4A is formed by joining a plurality of solder particles 11A, and the cured part 4B is formed by thermosetting the thermosetting component 11B. If the solder particles 11A are sufficiently moved, the first electrode 2a and the second electrode are moved after the movement of the solder particles 11A not located between the first electrode 2a and the second electrode 3a starts. It is not necessary to keep the temperature constant until the movement of the solder particles 11A is completed.

  In the present embodiment, it is preferable that no pressure is applied in the second step and the third step. In this case, the weight of the second connection target member 3 is added to the conductive material 11. For this reason, the solder particles 11A are more effectively collected between the first electrode 2a and the second electrode 3a when the connection portion 4 is formed. In addition, if pressure is applied in at least one of the second step and the third step, the solder particles 11A tend to collect between the first electrode 2a and the second electrode 3a. The tendency to be inhibited becomes high.

  Moreover, in this embodiment, since pressurization is not performed, the first connection target member 2 and the second connection target member 3 are in a state where the alignment between the first electrode 2a and the second electrode 3a is shifted. Can be corrected, the first electrode 2a and the second electrode 3a can be connected (self-alignment effect). This is because the molten solder self-aggregating between the first electrode 2a and the second electrode 3a is different from the solder between the first electrode 2a and the second electrode 3a and other conductive materials. This is because, when the area in contact with the component is minimized, the energy becomes more stable, and thus the force for forming the aligned connection structure, which is the connection structure having the minimum area, acts. At this time, it is desirable that the conductive material is not cured and that the viscosity of components other than the solder particles of the conductive material is sufficiently low at that temperature and time.

  The viscosity (ηmp) of the conductive material at the melting point of the solder is preferably 50 Pa · s or less, more preferably 10 Pa · s or less, further preferably 1 Pa · s or less, preferably 0.1 Pa · s or more, more preferably Is 0.2 Pa · s or more. When the viscosity (ηmp) is equal to or lower than the upper limit, the solder can be efficiently aggregated on the electrode. When the viscosity (ηmp) is equal to or higher than the lower limit, voids at the connection portion can be suppressed, and the protruding of the conductive material to other than the connection portion can be suppressed.

  The viscosity (ηmp) is STRESSTECH (manufactured by REOLOGICA) etc., strain control 1 rad, frequency 1 Hz, temperature rising rate 20 ° C./min, measurement temperature range 25-200 ° C. (however, the melting point of the solder is 200 ° C.) If it exceeds the upper limit, the upper limit of the temperature is taken as the melting point of the solder). From the measurement results, the viscosity at the melting point (° C.) of the solder is evaluated.

  In this way, the connection structure 1 shown in FIG. 1 is obtained. The second step and the third step may be performed continuously. Moreover, after performing the said 2nd process, the laminated body of the 1st connection object member 2, the electrically-conductive material 11, and the 2nd connection object member 3 which are obtained is moved to a heating part, and the said 3rd connection object is carried out. You may perform a process. In order to perform the heating, the laminate may be disposed on a heating member, or the laminate may be disposed in a heated space.

  The heating temperature in the third step is preferably 140 ° C. or higher, more preferably 160 ° C. or higher, preferably 450 ° C. or lower, more preferably 250 ° C. or lower, and even more preferably 200 ° C. or lower.

  As the heating method in the third step, a method of heating the entire connection structure using a reflow furnace or an oven above the melting point of the solder and the curing temperature of the thermosetting component, or a connection structure The method of heating only the connection part of these is mentioned.

  As a tool used for the method of heating locally, a hot plate, a heat gun for applying hot air, a soldering iron, an infrared heater, and the like can be given.

  In addition, when heating locally with a hot plate, the metal directly under the connection is made of a metal with high thermal conductivity, and other places where heating is not preferred are made of a material with low thermal conductivity such as a fluororesin. The upper surface of the hot plate is preferably formed.

  The said 1st, 2nd connection object member is not specifically limited. Specifically as said 1st, 2nd connection object member, electronic components, such as a semiconductor chip, a semiconductor package, LED chip, LED package, a capacitor | condenser, a diode, and a resin film, a printed circuit board, a flexible printed circuit board, flexible Examples thereof include electronic components such as circuit boards such as flat cables, rigid flexible boards, glass epoxy boards, and glass boards. The first and second connection target members are preferably electronic components.

  It is preferable that at least one of the first connection target member and the second connection target member is a resin film, a flexible printed board, a flexible flat cable, or a rigid flexible board. The second connection target member is preferably a resin film, a flexible printed board, a flexible flat cable, or a rigid flexible board. Resin films, flexible printed boards, flexible flat cables, and rigid flexible boards have the property of being highly flexible and relatively lightweight. When a conductive film is used for connection of such a connection object member, there exists a tendency for a solder not to gather on an electrode. On the other hand, by using a conductive paste, even if a resin film, a flexible printed circuit board, a flexible flat cable, or a rigid flexible circuit board is used, the conductive reliability between the electrodes can be efficiently collected by collecting the solder on the electrodes. Can be increased sufficiently. When using a resin film, a flexible printed circuit board, a flexible flat cable, or a rigid flexible circuit board, compared to the case of using other connection target members such as a semiconductor chip, the conduction reliability between the electrodes by not applying pressure is improved. The improvement effect can be obtained more effectively.

  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, a silver electrode, a SUS 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, a silver 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, a silver 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. From the viewpoint of more efficiently arranging the solder on the electrode, the electrode provided on the connection target member is preferably a gold electrode, a silver electrode, a copper electrode, or an aluminum electrode.

  In the connection structure according to the present invention, it is preferable that the first electrode and the second electrode are arranged in an area array or a peripheral. In the case where the first electrode and the second electrode are arranged in an area array or a peripheral, the effect of the present invention is more effectively exhibited. The area array is a structure in which electrodes are arranged in a grid pattern on the surface on which the electrodes of the connection target members are arranged. The peripheral is a structure in which electrodes are arranged on the outer periphery of a connection target member. In the case of a structure in which the electrodes are arranged in a comb shape, the solder may be aggregated along the direction perpendicular to the comb, whereas in the area array or peripheral structure, the electrode is disposed on the entire surface. It is necessary that the solder agglomerates uniformly. Therefore, in the conventional method, the amount of solder tends to be non-uniform, whereas in the method of the present invention, the solder can be uniformly aggregated on the entire surface.

  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.

Thermosetting component (thermosetting compound):
Thermosetting compound 1: bisphenol F type epoxy compound, “YDF-8170C” manufactured by Nippon Steel & Sumikin Chemical Co., SP value: 23.4, specific gravity: 1.20
Thermosetting compound 2: bisphenol A type epoxy compound, “YD-8125” manufactured by Nippon Steel & Sumikin Chemical Co., SP value: 22.3, specific gravity: 1.16
Thermosetting compound 3: phenol novolac type epoxy compound, “DEN431” manufactured by DOW, SP value: 24.6, specific gravity: 1.15
Thermosetting compound 4: aliphatic epoxy compound, “Epolite 1600” manufactured by Kyoeisha Chemical Co., SP value: 20.0, specific gravity: 1.03
Thermosetting compound 5: epoxy compound containing isocyanuric skeleton, “TEPIC-SP” manufactured by Nissan Chemical Industries, SP value: 41.1, specific gravity: 1.45

Thermosetting component (thermosetting agent):
Thermosetting agent 1: Acid anhydride curing agent, “Ricacid TH” manufactured by Shin Nippon Chemical Co., Ltd., SP value: 24.8, specific gravity: 1.38
Thermosetting agent 2: Acid anhydride curing agent, “Ricacid MH” manufactured by Shin Nippon Chemical Co., Ltd., SP value: 19.4, specific gravity: 1.36

Thermosetting component (curing accelerator):
Curing accelerator 1: Organic phosphonium salt, “PX-4MP” manufactured by Nippon Chemical Industry Co., Ltd.

Activator:
Activator 1: Acid phosphate ester compound (butyl acid phosphate), “JP-504” manufactured by Johoku Chemical Industry Co., Ltd., liquid at room temperature, SP value: 25.1
Activator 2: Acid phosphate ester compound (ethyl acid phosphate), “JP-502” manufactured by Johoku Chemical Industry Co., Ltd., liquid at room temperature, SP value: 28.0
Activator 3: “Stearic acid” manufactured by Wako Pure Chemical Industries, Ltd., solid at normal temperature, SP value: 18.7
Activator 4: “Diethylphosphonoacetic acid” manufactured by Johoku Chemical Industry Co., Ltd., liquid at room temperature, SP value: 20.0
Activator 5: “Glutaric acid benzylamine salt”, melting point 108 ° C., solid at room temperature, SP value: 29.2

Method for preparing activator 5:
In a glass bottle, 24 g of water as a reaction solvent and 13.212 g of glutaric acid (manufactured by Wako Pure Chemical Industries, Ltd.) were added and dissolved until uniform at room temperature. Thereafter, 10.715 g of benzylamine (manufactured by Wako Pure Chemical Industries, Ltd.) was added and stirred for about 5 minutes to obtain a mixed solution. The obtained mixture was put in a refrigerator at 5 to 10 ° C. and left overnight. The precipitated crystals were collected by filtration, washed with water, and dried under vacuum to obtain Activator 5.

  Activator 6: “Adipic acid benzylamine salt”, melting point 170 ° C., solid at room temperature, SP value: 28.2

Method for preparing activator 6:
In a glass bottle, 24 g of water as a reaction solvent and 14.61 g of adipic acid (manufactured by Wako Pure Chemical Industries, Ltd.) were added and dissolved at room temperature until uniform. Thereafter, 10.715 g of benzylamine (manufactured by Wako Pure Chemical Industries, Ltd.) was added and stirred for about 5 minutes to obtain a mixed solution. The obtained mixture was put in a refrigerator at 5 to 10 ° C. and left overnight. The precipitated crystals were collected by filtration, washed with water, and dried under vacuum to obtain activator 6.

Activator 7: “Citric acid” manufactured by Wako Pure Chemical Industries, Ltd., solid at room temperature, SP value: 33.8
Activator 8: “Malic acid” manufactured by Wako Pure Chemical Industries, solid at room temperature, SP value: 31.5

Conductive particles (solder particles, conductive particles containing solder other than solder particles (conductive particles X)):
Conductive particles 1: SnBi solder particles, melting point 138 ° C., solder particles selected from Mitsui Kinzoku “Sn42Bi58”, average particle size: 20 μm
Conductive particles 2: SnBi solder particles, melting point 138 ° C., solder particles selected from Mitsui Kinzoku “Sn42Bi58”, average particle size: 10 μm
Conductive particles 3: SnBi solder particles, melting point 138 ° C., solder particles selected from Mitsui Kinzoku “Sn42Bi58”, average particle size: 7 μm
Conductive particles 4: SnBi solder particles, melting point 138 ° C., solder particles selected from Mitsui Kinzoku “Sn42Bi58”, average particle size: 5 μm
Conductive particles 5: SnBi solder particles, melting point 138 ° C., solder particles selected from Mitsui Kinzoku “Sn66Bi34”, average particle size: 10 μm
Conductive particles 6: SnAgCu solder particles, “SnAg3Cu0.5” manufactured by Mitsui Mining & Smelting Co., Ltd., average particle size: 10 μm, melting point: 217 ° C.

SP values of thermosetting compounds, thermosetting agents and activators:
The SP values of the thermosetting compound, thermosetting agent and activator were calculated by the Fedors estimation method.

(Examples 1-13 and Comparative Examples 1-9)
(1) Preparation of conductive material (anisotropic conductive paste) The components shown in the following Tables 1 and 2 are blended in the blending amounts shown in Tables 1 and 2 to obtain a conductive material (anisotropic conductive paste). It was.

(2) Production of connection structure As a first connection target member, a glass epoxy substrate (material: FR−) having a gold electrode (electrode length: 650 μm, electrode thickness: 28 μm) on the surface as L / S = 350 μm / 300 μm 4, thickness: 0.6 mm).

  As a second connection target member, a glass epoxy substrate (material: FR-4, thickness: 0.6 mm) having a gold electrode (electrode length: 650 μm, electrode thickness: 28 μm) on the surface as L / S = 350 μm / 300 μm Prepared.

  A conductive material (anisotropic conductive paste) immediately after fabrication was applied to the upper surface of the glass epoxy substrate so as to have a thickness of 100 μm, thereby forming a conductive material (anisotropic conductive paste) layer. Next, a glass epoxy substrate was laminated on the upper surface of the conductive material (anisotropic conductive paste) layer so that the electrodes face each other. The weight of the glass epoxy substrate is added to the conductive material (anisotropic conductive paste) layer. From this state, heating was performed so that the temperature of the conductive material (anisotropic conductive paste) layer became the melting point of the conductive particles within 60 seconds from the start of temperature increase. Furthermore, the conductive material (anisotropic conductive paste) layer is heated so that the temperature of the conductive material (anisotropic conductive paste) layer becomes 140 ° C. to 160 ° C. for 240 seconds after reaching the melting point, and the conductive material (anisotropic conductive paste) layer is cured. Got. No pressure was applied during heating.

(Evaluation)
(1) Absolute value of difference between SP value of mixture (M) of thermosetting compound and thermosetting agent and SP value of activator SP value of mixture (M) of thermosetting compound and thermosetting agent From the SP value of the activator, the absolute value of the difference between the SP value of the mixture (M) of the thermosetting compound and the thermosetting agent and the SP value of the activator was calculated. In addition, SP value of the mixture (M) of a thermosetting compound and a thermosetting agent was computed by the following formula.

SP value of mixture (M) of thermosetting compound and thermosetting agent = SP1 × φ1 + SP2 × φ2
SP1: SP value of the thermosetting compound φ1: Volume fraction of the thermosetting compound in the mixture (M) of the thermosetting compound and the thermosetting agent SP2: SP value of the thermosetting agent φ2: With the thermosetting compound Volume fraction of thermosetting agent in mixture (M) with thermosetting agent

(2) Shape maintenance characteristic of conductive material A glass epoxy substrate used for production of a connection structure was prepared. On the electrode of the glass epoxy substrate, the obtained conductive material was applied so as to have a width of 10 mm, a length of 10 mm, and a thickness of 100 μm, and the conductive material was laminated. The laminated conductive material was observed with X-rays, the width and length of the conductive material were measured, and the area (S1) occupied by the conductive material before heating was calculated. The glass epoxy board | substrate which apply | coated the electrically-conductive material was heated on 70 degreeC and the conditions for 10 minutes. The conductive material after heating was observed with X-rays, the width and length of the conductive material were measured, and the surface group (S2) occupied by the conductive material after heating was calculated. S2 (S2 / S1) relative to S1 was calculated from the obtained measurement results. The shape maintenance characteristics of the conductive material were determined according to the following criteria.

[Judgment criteria for shape maintenance characteristics of conductive materials]
○: S2 / S1 is 1.1 or less Δ: S2 / S1 exceeds 1.1 and 1.2 or less X: S2 / S1 exceeds 1.2

(3) Solder placement accuracy on the electrode In the obtained first, second, third, and fourth connection structures, the first electrode and the second electrode in the stacking direction of the first electrode, the connection portion, and the second electrode. The ratio of the area where the solder part in the connection part is arranged in 100% of the area of the part where the first electrode and the second electrode face each other when the part facing the two electrodes is seen X was evaluated. The placement accuracy of the solder on the electrode was determined according to the following criteria.

[Criteria for solder placement accuracy on electrodes]
○○○: Ratio X is 80% or more ○○: Ratio X is 70% or more and less than 80% ○: Ratio X is 60% or more and less than 70% Δ: Ratio X is 50% or more and less than 60% X: Ratio X is 50 %Less than

(4) Conduction reliability between upper and lower electrodes In the obtained connection structure (n = 15), the connection resistance per connection point between the upper and lower electrodes was measured by a four-terminal method. The average value of connection resistance was calculated. Note that the connection resistance can be obtained by measuring the voltage when a constant current is passed from the relationship of voltage = current × resistance. The conduction reliability was determined according to the following criteria.

[Judgment criteria for conduction reliability]
○○: The average value of connection resistance is 50 mΩ or less ○: The average value of connection resistance exceeds 50 mΩ and 70 mΩ or less △: The average value of connection resistance exceeds 70 mΩ and 100 mΩ or less ×: The average value of connection resistance exceeds 100 mΩ, or There is a bad connection

(5) Insulation reliability between adjacent electrodes In the obtained connection structure (n = 15), after leaving in an atmosphere of 85 ° C. and 85% humidity for 100 hours, 5 V is applied between adjacent electrodes. The resistance value was measured at 25 locations. Insulation reliability was judged according to the following criteria.

[Criteria for insulation reliability]
○: Average connection resistance is 10 ⁷ Ω or more ○: Average connection resistance is 10 ⁶ Ω or more and less than 10 ⁷ Ω Δ: Average connection resistance is 10 ⁵ Ω or more and less than 10 ⁶ Ω ×: Connection resistance Average value less than 10 ⁵ Ω

  The results are shown in Tables 1 and 2 below.

  The same tendency was observed even when a resin film, a flexible flat cable, and a rigid flexible substrate were used.

DESCRIPTION OF SYMBOLS 1,1X ... Connection structure 2 ... 1st connection object member 2a ... 1st electrode 3 ... 2nd connection object member 3a ... 2nd electrode 4, 4X ... Connection part 4A, 4XA ... Solder part 4B, 4XB ... cured material part 11 ... conductive material 11A ... solder particle 11B ... thermosetting component 21 ... conductive particle 31 ... conductive particle 32 ... base particle 33 ... conductive part 33A ... second conductive part 33B ... first conductive Part 41 ... Conductive particles 42 ... Conductive part

Claims (8)

A thermosetting component, a plurality of conductive particles, and an activator that removes an oxide film of the conductive particles;
The thermosetting component comprises a thermosetting compound;
The thermosetting component does not contain or contain a thermosetting agent;
When the thermosetting component does not contain the thermosetting agent, the absolute value of the difference between the SP value of the thermosetting compound and the SP value of the activator is 2 or less,
When the thermosetting component contains the thermosetting agent, the absolute value of the difference between the SP value of the mixture of the thermosetting compound and the thermosetting agent and the SP value of the activator is 2 or less. A conductive material.   The conductive material according to claim 1, wherein the conductive particles include tin, bismuth, copper, gold, silver, or indium.   The conductive material according to claim 1, wherein the activator is an acidic phosphate ester.   The conductive material according to claim 1, wherein an acid value of the activator is 280 mgKOH / g or more and 580 mgKOH / g or less.   The conductive material according to claim 1, wherein the activator has an SP value of 20 or more and 28 or less.   The conductive material according to claim 1, wherein a content of the activator with respect to 100 parts by weight of the thermosetting compound is 1 part by weight or more and 10 parts by weight or less. A first connection object member having a first electrode on its surface;
A second connection target member having a second electrode on its surface;
A connecting portion connecting the first connection target member and the second connection target member;
The material of the connection part is the conductive material according to any one of claims 1 to 6,
A connection structure in which the first electrode and the second electrode are electrically connected by the connection portion. Using the conductive material according to claim 1, disposing the conductive material on the surface of the first connection target member having the first electrode on the surface;
On the surface opposite to the first connection target member side of the conductive material, the second connection target member having the second electrode on the surface is opposed to the first electrode and the second electrode. A step of arranging to
By heating the conductive material to a temperature equal to or higher than the melting point of the conductive particles, a connection portion connecting the first connection target member and the second connection target member is formed of the conductive material, and A method for manufacturing a connection structure, comprising: electrically connecting the first electrode and the second electrode by the connection portion.

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